Revision 13 - UMKC Senior Design - Home



SENIOR PROJECT DESIGNSUBSTATION GROUPECE-402WISUBSTATION DESIGN MANUALRevision 13098743October December 11February 7th, 20131st, 2013(Page Intentionally Left Blank)Table of Contents13.6 Substation Lighting1.7 Controls House1.7.1 Construction1.7.2 Flooring1.7.3 Battery Station1.7.4 Protective Fire Wall1.7.5 HVACSection 5 - Substation Equipment5 Protective Relaying5.1 Purpose5.2 Relay Panel Specifications5.3 Relay SpecificationsSection 6 - Communications6 Communications6.1 Communications Equipment6.2 Additional CommunicationsSection 7 - Substation Grounding7.1 Introduction7.2 General Requirements7.3 Design Specification7.4 Design Criteria7.4.1 Soil Testing7.4.2 Ground Fault Currents7.4.3 Fault Current Split Calculation7.4.4 Ground Conductor(Conductor Material)7.4.5 Ground Conductor Sizing (Ampacity Calculation)7.4.6 Connections From Equipment and Stricter to Grounding Grid7.4.7 Addition of Surface Layer & Reduction Factor7.5 Safety Considerations7.5.1 Tolerable Limits of Body Currents7.5.2 Touch and Step Voltage Limits7.5.3 GPR (Ground Potential Rise)7.6 Substation Fence GroundingIntroductionThis substation design manual defines the design criteria calculated and/or selected and supported by the members of the Substation Design Group of course ECE-402WI for use with the 138 kV UMKC Substation Project. The members of this group and their primary responsibilities are:Zane Potts- Power TransformerPayam Ansari- Circuit BreakersBrandon Howland- Protective RelayingRobert Biggs- Lightning MitigationEhab Abdelhaq- GroundingGary Kertz- Substation LayoutFROM THIS POINT ON GENTLEMEN PLEASE EDIT YOUR RELEVANT SECTION AND OTHER AREAS TO COMPLETE THIS DOCUMENT – I LEFT THE ORIGIBAL MATERIAL SHOULD ANY BE OF USE. FEEL FREE TO USE TEXT FROM THE B&McD SUBSTATION DESIGN MANUAL TO SUPPLEMENT YOUR INPUT. SEND ALL YOUR WRITEUPS TO MARIA COTE AS WELL AS INCLUDING HERE> REVISE PER MARIA's COMMENTSThe 138 kV UMKC Substation will be a conventional outdoor, open air insulated, low profile, rigid bus design, utilizing SF6 circuit breakers and vertical break disconnect switches configured in a three position ring bus arrangement. The arrangement will consist of one transmission line connection to the new load in the East Bottoms and one transmission line connection to the new load in the West Bottoms and a transformer bay consisting of a 138 kV to 69 kV transformer and a 69 kV transmission line as shown on the electrical one-line diagram submitted.Table of Contents TOC \t "Chapter,1,Section,2,Sub 1,3,Sub 2,4,Appendix,1,Appendix Sub,2" 1 - Site Design PAGEREF _Toc379564637 \h 41.1Roadways PAGEREF _Toc379564638 \h 41.2Site Surfacing PAGEREF _Toc379564639 \h 41.3Fencing and Landscaping PAGEREF _Toc379564640 \h 41.4Security PAGEREF _Toc379564641 \h 41.5Signage PAGEREF _Toc379564642 \h 41.6Substation Lighting PAGEREF _Toc379564643 \h 41.7Control House PAGEREF _Toc379564644 \h 41.7.1 - Construction PAGEREF _Toc379564645 \h 41.7.2 - Flooring PAGEREF _Toc379564646 \h 51.7.3 - Battery Station PAGEREF _Toc379564647 \h 51.7.4 - Protective Fire Wall PAGEREF _Toc379564648 \h 51.7.5 - HVAC PAGEREF _Toc379564649 \h 52 - Substation Structure Design PAGEREF _Toc379564650 \h 52.1Material PAGEREF _Toc379564651 \h 52.2Design PAGEREF _Toc379564652 \h 52.2.1 - Switch Support Structures PAGEREF _Toc379564653 \h 52.2.2 - Bus and Insulator Support Structures PAGEREF _Toc379564654 \h 62.2.3 - Dead end Structures PAGEREF _Toc379564655 \h 62.3Transformer Bunding PAGEREF _Toc379564656 \h 63 - Bus construction PAGEREF _Toc379564659 \h 73.1Basic Impulse Insulation Level PAGEREF _Toc379564664 \h 73.1.1 - Insulation Coordination PAGEREF _Toc379564665 \h 73.2Environmental Considerations PAGEREF _Toc379564666 \h 73.3Clearances and Spacing PAGEREF _Toc379564667 \h 83.4Bus Assembly Design PAGEREF _Toc379564668 \h 83.4.1 - Bus Conductors PAGEREF _Toc379564670 \h 83.4.1.1 - Aeolian Dampening PAGEREF _Toc379564671 \h 83.4.2 - Bus Fittings PAGEREF _Toc379564672 \h 93.4.3 - Bus Expansion Joints. PAGEREF _Toc379564673 \h 93.4.4 - Transition Plates. PAGEREF _Toc379564674 \h 93.4.5 - Bus conductor supports PAGEREF _Toc379564675 \h 93.4.6 - Bus Elevation and Spacing PAGEREF _Toc379564676 \h 93.5Insulator Selection PAGEREF _Toc379564677 \h 93.5.1 - Station Post Insulators PAGEREF _Toc379564678 \h 93.5.2 - Suspension Insulators PAGEREF _Toc379564679 \h 103.6Raceway Systems PAGEREF _Toc379564680 \h 103.6.1 - Raceway Drawings PAGEREF _Toc379564681 \h 104 - Substation Equipment PAGEREF _Toc379564682 \h 114.1Circuit Breakers PAGEREF _Toc379564683 \h 114.1.1 - Circuit Breakers (Located at 138KV side of the transformer) PAGEREF _Toc379564684 \h 124.1.2 - Circuit Breaker (Located at 69KV side of the transformer) PAGEREF _Toc379564685 \h 134.1.3 - Disconnect Switches PAGEREF _Toc379564686 \h 144.1.3.1 - Disconnect Switches (Located on both sides of 138KV breakers) PAGEREF _Toc379564691 \h 144.1.3.2 - Disconnect Switches (Located on both sides of 69KV breaker) PAGEREF _Toc379564692 \h 144.1.3.3 - Disconnect Switch for Control Power (Single Phase Switch) PAGEREF _Toc379564693 \h 154.1.4 - Motor Operated Air Break (MOAB) Switch PAGEREF _Toc379564694 \h 154.2Surge Arresters PAGEREF _Toc379564697 \h 174.3Power Transformer PAGEREF _Toc379564698 \h 184.3.1 - Rating and Technical Details PAGEREF _Toc379564699 \h 184.3.2 - Tank Construction PAGEREF _Toc379564703 \h 194.3.3 - Operation and Status Components PAGEREF _Toc379564704 \h 204.3.4 - Valves and Safety Components PAGEREF _Toc379564705 \h 204.3.5 - Grounding PAGEREF _Toc379564706 \h 224.3.6 - Transportation PAGEREF _Toc379564707 \h 224.3.7 - Surge Arrester Mounts PAGEREF _Toc379564708 \h 224.3.8 - Transformer Bushings PAGEREF _Toc379564709 \h 234.3.9 - De-energized Tap Changer (DETC) PAGEREF _Toc379564710 \h 234.3.10 - Conservator PAGEREF _Toc379564711 \h 234.3.11 - Cooling PAGEREF _Toc379564712 \h 234.3.12 - Fans PAGEREF _Toc379564713 \h 244.3.13 - Controls PAGEREF _Toc379564714 \h 244.3.14 - Noise PAGEREF _Toc379564715 \h 244.3.15 - Tertiary Winding PAGEREF _Toc379564716 \h 244.3.16 - Neutrals PAGEREF _Toc379564717 \h 244.4Coupling Capacitor Voltage Transformers PAGEREF _Toc379564719 \h 254.5Lightning Shielding PAGEREF _Toc379564720 \h 254.5.1 - Design PAGEREF _Toc379564721 \h 254.5.2 - Masts PAGEREF _Toc379564722 \h 264.5.3 - Installation PAGEREF _Toc379564723 \h 264.6DC Station Service (more precise details to be determined) PAGEREF _Toc379564734 \h 265 - Protective Relaying PAGEREF _Toc379564739 \h 275.1Purpose PAGEREF _Toc379564740 \h 275.2Relay Panel Specifications PAGEREF _Toc379564741 \h 285.3Relay Specifications PAGEREF _Toc379564742 \h 296 - Communication PAGEREF _Toc379564743 \h 316.1Communications Equipment PAGEREF _Toc379564744 \h 316.2Additional Communication PAGEREF _Toc379564745 \h 317 - Substation grounding PAGEREF _Toc379564746 \h 327.1Introduction PAGEREF _Toc379564747 \h 327.2General Requirements PAGEREF _Toc379564748 \h 327.3Design Specification PAGEREF _Toc379564749 \h 327.4Design Criteria PAGEREF _Toc379564778 \h 337.4.1 - Soil Testing PAGEREF _Toc379564779 \h 337.4.2 - Ground Fault Currents PAGEREF _Toc379564780 \h 357.4.3 - Fault Current Split Calculation PAGEREF _Toc379564782 \h 367.4.4 - Ground Conductor(Conductor Material) PAGEREF _Toc379564783 \h 367.4.5 - Ground Conductor Sizing (Ampacity Calculation) PAGEREF _Toc379564784 \h 367.4.6 - Connections From Equipment and Stricter to Grounding Grid PAGEREF _Toc379564785 \h 377.4.7 - Addition of Surface Layer & Reduction Factor PAGEREF _Toc379564786 \h 377.5Safety Considerations PAGEREF _Toc379564787 \h 387.5.1 - Load and fault studies: PAGEREF _Toc379564788 \h 387.5.2 - Tolerable Limits of Body Currents PAGEREF _Toc379564789 \h 387.5.3 - Touch and Step Voltage Limits PAGEREF _Toc379564790 \h 397.5.4 - GPR (Ground Potential Rise) PAGEREF _Toc379564791 \h 397.6Substation Fence Grounding PAGEREF _Toc379564792 \h 39Appendix A - Equations PAGEREF _Toc379564793 \h 41Wind Loads: PAGEREF _Toc379564794 \h 41Span or Support Spacing: PAGEREF _Toc379564795 \h 42Grounding: PAGEREF _Toc379564796 \h 43Lightning and Shielding: PAGEREF _Toc379564797 \h 44Momentary Current: PAGEREF _Toc379564798 \h 45Busbar Expansion PAGEREF _Toc379564799 \h 46Cantilever Strength: PAGEREF _Toc379564800 \h 47Short Circuit Force: PAGEREF _Toc379564801 \h 48Appendix B - Bus Height PAGEREF _Toc379564802 \h 49Appendix C - Rigid Bus Spreadsheet PAGEREF _Toc379564803 \h 50Appendix D - Isokeraunic Chart PAGEREF _Toc379564804 \h 52Appendix E - Communications PAGEREF _Toc379564805 \h 541Site DesignRoadwaysA 20ft wide road, as per design guide, will follow the interior perimeter of the substation security fence. The road will consist of a 200 mm (8-inch) aggregate base course and a 100 mm (4-inch) aggregate surface course. Pipe arch will be utilized anywhere roadway will cross a potential wiring trench location within the Substation.Site SurfacingThe entire yard, as well as a 1 meter (3 feet) perimeter beyond the substation fence, will be covered with 4 to 6 inches of crushed rock or stone. Prior to surfacing, the ground will be sterilized in order to prevent vegetation growth.Fencing and LandscapingDue to the inherent dangers associated with a substation it is necessary to prevent unauthorized access. A security fence utilizing a one foot barbed wire extension will be constructed from galvanized chain link fabric for this purpose. It will extend around the perimeter of the site. To allow entrance for utility and service traffic there shall be two 16-foot manually operated swing gates installed. They will be of chain link construction.SecurityFencing will include provisions to facilitate locking of the entrance gates of the substation, but no further security measures will be provided.SignageSignage will be provided expressing the dangers within the substation as well and informing individuals that unauthorized admittance is not allowed. This signage will be well lit and in ordinance with the specifications given by the National Electrical Safety Code (NESC).Substation LightingLighting fixtures will be affixed to bus support structures. Density will be such as to provide sufficient lighting to meet local code for maintenance and repair on the substation. Control HouseConstructionThe superstructure will be a windowless pre manufactured metal building constructed from fire-resistant low maintenance materials. Per NEC or UBC code it will have two entry doors.Flooring The control house floor will be a floating concrete slab 12.7 to 15.2 cm (5 to 6 inches) thick reinforced with welded wire fabric. Elevation will be 6 inches above the finished grade of the outside of the control house.Battery StationBattery station will be 125 VDC as requested by Burns and McDonnell . Charge will be maintained through the use of a primary as well as a backup charger.Protective Fire WallThe controls house will be located at a distance greater than 50 ft. from the transformer therefore a protective fire wall will not be necessary at this time.HVACHeating and Cooling will be provided and sized as to maintain a range of 60 – 80 degrees Fahrenheit within the control structure. The Unit will be located on the roof of the structure as to aid in security.1.1RoadwaysA 20ft wide road, as per design guide, will follow the interior perimeter of the substation security fence. The road will consist of a 200 mm (8-inch) aggregate base course and a 100 mm (4-inch) aggregate surface course. Pipe arch will be utilized anywhere roadway will cross a potential wiring trench location within the Substation.1.21Site SurfacingThe entire yard as well as a 1 meter (3 feet) perimeter beyond the substation fence will be covered with 4 to 6 inches of crushed rock or stone. Prior to surfacing, the ground will be sterilized in order to prevent vegetation growth.1.32Fencing and LandscapingDue to the inherent dangers associated with a substation it is necessary to prevent unauthorized access. A security fence utilizing a one foot barbed wire extension will be constructed from galvanized chain link fabric for this purpose. It will extend around the perimeter of the site. To allow entrance for utility and service traffic there shall be two 16-foot manually operated swing gates installed. They will be of chain link construction.1.43SecurityFencing will include provisions to facilitate locking of the entrance gates of the substation but no further security measures will be provided.1.53SignageSignage will be provided expressing the dangers within the substation as well and informing individuals that unauthorized admittance is not allowed. This signage will be well lit and in ordinance with the specifications given by the National Electrical Safety Code (NESC).1.6Substation LightingLighting fixtures will be affixed to bus support structures. Density will be such as to provide sufficient lighting to meet local code for maintenance and repair on the substation. 1.7Controls House1.7.1ConstructionThe superstructure will be a windowless pre manufactured metal building constructed from fire-resistant low maintenance materials. Per NEC or UBC code it will have two entry doors.1.7.2Flooring The control house floor will be a floating concrete slab 12.7 to 15.2 cm (5 to 6 inches) thick reinforced with welded wire fabric. Elevation will be 6 inches above the finished grade of the outside of the control house.1.7.3Battery StationBattery station will be 125 VDC as requested by Burns and McDonnell . Charge will be maintained through the use of a primary as well as a backup charger.1.7.4Protective Fire WallThe controls house will be located at a distance greater than 50 ft. from the transformer therefore a protective fire wall will not be necessary at this time.1.7.5HVACHeating and Cooling will be provided and sized as to maintain a range of 60 – 80 degrees Fahrenheit within the control structure. The Unit will be located on the roof of the structure as to aid in security.2SwitchyardSubstation Structure Design2.1MaterialEquipment support and dead-end structures will be designed using folded-plate tapered tubular steel. All yard structures will be ASTM A36 steel hot-dip galvanized for corrosion protection per supplied design manual. All welding fabrication of structures will be performed prior to the galvanization process. 2.2 DesignThe steel structures will be designed using the Allowable Stress Design (ASD) approach as defined by the American Institute of Steel Construction’s (AISC) Manual of Steel Construction, ASD. All structures shall conform to the requirements of Part 36 of NEMA Publication SG 6.Base plates for all support structures shall be designed to rest on leveling screws which will allow for error in level and trueness of the foundation surface as well as aid in structure alignment resulting from fabrication tolerances and buswork fit up.2.2.1Switch Support StructuresSwitch support structures will be designed to remain within the deflection limitations as specified in Section SG6-36.03 of NEMA Publication SG 62.2.2Bus and Insulator Support StructuresBus support structures and other stationary equipment stands shall be designed as to prevent deflections greater than 1/200 of the bus height under listed environmental conditions.2.2.3Dead end StructuresLines entering and leaving the substation shall have less than 1000 lbs. tension per phase, terminating to a Dead End structure. The Dead End structure will be of an A frame configuration constructed from structural tubing and of the outboard leg design. Transformer BundingTo prevent oil migration to the environment or other site equipment in the case of a spill, a humped bund constructed of concrete will surround the power transformer. Flooring within the bund will be 1% grade, as to direct flows to an 18’ deep sump to allow for pump down of materials captured within the bund. The containment basin will be fitted with a Parallel Plate Separator (PPS) to allow for rainwater/oil separation.The dimensions will be such that it will be capable of containing 110% of the oil capacity of the transformer while allowing the bund walls to be a distance from the transformer which is greater than half the height of the oil level contained within it.These dimensions will be called out in the layout drawing next semester once the size and capacity of the transformer is known.3Bus construction3.1General3.1.1Basic Impulse Insulation LevelThe Basic Impulse Insulation Level was provided by Burns and McdonnellMcDonnell. to be 550 kVKv for the 138 KvkV line and 350 KvkV for the 69 KvkV side. 3.1.1.1 Insulation CoordinationAn insulation coordination study will not be necessary due to the BIL value having been provided by Burns and McdonnellMcDonnell.3.1.2Environmental ConsiderationsThe following environmental factors will be used in determining the most optimal design of the substation bus, insulators and support structures.ElevationLess than 2,000 feetIsokeraunic Level50 – 60 days???????Wind and Ice LoadingDesign greatest 3 sec duration speeds at 30 ft.70 mphDesign Maximum Ice-Radial Thicknesss0.5 inchSeismic Conditions Risk Zone2 A3.23Clearances and SpacingThe 138 kV switchyardsubstation facilities will be designed to maintain a minimum of the following clearances and spacing based on the desired 550 kVKv BIL:Rigid bus center-to-center phase spacing, minimum, inches84 in Minimum phase-to-phase, metal-to-metal distance, inches53 inMinimum phase-to-ground, feet12 ftMinimum vertical clearance from roadway, feet25 ftThe 69 kV switchyardsubstation facilities will be designed to maintain a minimum of the following clearances and spacing based on the desired 350Kv BIL:Rigid bus center-to-center phase spacing, (minimum), inches60 in Minimum phase-to-phase, metal-to-metal distance, inches31 inMinimum phase-to-ground, feet11 ftMinimum vertical clearance from roadway, feet23 ft 3.34 Bus Assembly DesignBus components will be sized in the design as to maintain uniformity of components and spacing requirements at both voltages. Sizing of components to maintain compliance with standards shall be determined through the use of Burns and McDonnell supplied spreadsheet.Results of spreadsheet can be observed in appendix A.Bus ConductorsThe outdoor tubular bus system will be constructed through the use of 3”, Schedule 40, 6061-T6, aluminum alloy material which possesses a maximum load rating of 2,272 amperes for the given conditions. Due to the increased allowable span that 5” tube would allow it is recommended that the client consider its use rather than 3” tube as the cost savings in foundation and support costs would be significant.Aeolian DampeningA 954 KCMIL aluminum damper will be utilized to reduce the Aeolian vibration.Bus FittingsFittings for the aluminum tubular bus shall be welded. Fittings for conductor jumpers will be welded bolted or compression type for all aluminum conductors to a bolted pad. Equipment terminal connections will be NEMA 4-hole bolted type to allow for easy removal when performing equipment maintenance, repair, or replacement. 3.34.1Bus ConductorsThe outdoor tubular bus system will be constructed through the use of 3”, Schedule 40, 6061-T6, aluminum alloy material which possesses a maximum load rating of 2,272 amperes for the given conditions. Due to the increased allowable span that 5” tube would allow it is recommended that the client consider its use rather than 3” tube as the cost savings in foundation and support costs would be significant.3.4.1.1Aeolian DampeningA 954 KCMIL aluminum damper will be utilized to reduce the Aeolian vibration.3.34.2Bus FittingsFittings for the aluminum tubular bus shall be welded. Fittings for conductor jumpers will be welded bolted or compression type for all aluminum conductors to a bolted pad. Equipment terminal connections will be NEMA 4-hole bolted type to allow for easy removal when preforming equipment maintenance, repair, or replacement. 3.34. 3Bus Expansion Joints.Each length of bus will be fitted with a single slip expansion joint which will be located at the end of the bus.3.34. 3 Transition Plates.Transition plates will not be necessary for this project due to the bus and all conductors being constructed of aluminum only.3.34. 4Bus conductor supportsBus conductors will be fixed on one end with the remaining supports slipping which results in a minimum support distance of 25 ft.Support will be performed through the use of the station post insulators which have been specified hereafter.3.34.1Bus Elevation and SpacingThe lower bus shall have a bus height of 15 feet above the foundation. This will be obtained through the insulator support structure having a height of 10.5 feet and the insulator height of 54 inches. The high bus shall be at a height of 25 feet. All bus bars will be spaced 10 feet from phase to phase centerline. 3.45Insulator SelectionAll insulators will be rated 550 kV BIL for the 138 KV as well as the 69 KV system to maintain uniformity. They will be dove grey in color and be of Polymer composition. 3.45.1Station Post InsulatorsANSI TR-289 station post insulators will be used on all bus supports and disconnect switches.Leakage Distance (inches):116Dry Arcing Distance (inches):54Dry Flashover (kV):435Wet Flashover (kV):335Cantilever strength (lbs.)22004 x 5” bolt circle with 5/8-11 threaded mounting 3.45.2Suspension InsulatorsANSI S025047H2010 suspension insulators will be used on all dead ends. Three additional bells will be included for high voltage dead ends and two for low voltage dead ends.Ratings:Leakage Distance (inches):142Dry Arcing Distance (inches):47.9Dry Flashover (kV):510Wet Flashover (kV):475Working load (lbs.)12500 3.56Raceway SystemsThe raceway systems will consist of below grade pre-cast cable trench and pipe arch will be utilized as the primary wire run with the use of PVC conduit as the secondary feeders which carry wiring to the individual devices. Transitions of wire ways will be supported by the use of hand holds. NEC codes will be recognized in the installation of all race ways and control wiring.3.56.1Raceway DrawingsDrawings will be generated with size and location of components that will make up the raceway system.3.67Switchyard LightingLighting fixtures will be affixed to bus support structures. Density will be such as to provide sufficient lighting to meet local code for maintenance and repair on the substation. 3.78Controls House3.75.1ConstructionThe superstructure will be a windowless pre manufactured metal building constructed from fire-resistant low maintenance materials. Per NEC or UBC code it will have two entry doors.3.78.2Flooring The control house floor will be a floating concrete slab 12.7 to 15.2 cm (5 to 6 inches) thick reinforced with welded wire fabric. Elevation will be 6 inches above the finished grade of the outside of the control house.3.78.3Battery stationBattery station will be 125 VDC as requested by Burns and McdonellMcDonnell . Charge will be maintained through the use of a primary as well as a backup charger.3.78.4Protective Fire wallThe controls house will be located at a distance greater than 50 ft. from the transformer therefore a protective fire wall will not be necessary at this time.3.78.5HVACHeating and Cooling will be provided and sized as to maintain a range of 60 – 80 degrees Fahrenheit within the control structure. The Unit will be located on the roof of the structure as to aid in security.Transformer BundingTo prevent oil migration to the environment or other site equipment in the case of a spill, a humped bund constructed of concrete will surround the power transformer. Flooring within the bund will 1% grade as to direct flows to an 18’ deep sump to allow for pump down of materials captured within the bund. The containment basin will be fitted with a Parallel Plate Separator (PPS) to allow for rainwater/oil separation.The dimensions will be such that it will be capable of containing 110% of the oil capacity of the transformer while allowing the bund walls to be a distance from the transformer which is greater than half the height of the oil level contained within it.These dimensions will be called out in the layout drawing next semester once the size and capacity of the transformer is known.1.2.7Switchyard Substation EquipmentEquipmentThis section summarizes the major equipmentequipment in the switchyard substation facilitiesCircuit BreakersBy definition, a circuit breaker is a device that closes and interrupts (opens) an electric circuit between separable contacts under both load and fault conditions. The rating of a circuit breaker is a summary of its characteristics that identifies its application on an electric system, its performance capabilities, and its adaptability. This summary of characteristics is given principally in terms of voltages, currents, and time as described in the rating tables.This substation will use three 138KV breakers in a ring bus configuration, this ring bus will have two exit lines, and a single 138:69KV transformer line exit with breaker. Column A represents my calculations, scope contents, and IEEE Standards. Column B represents the data in breaker’s data sheet. Circuit Breakers (Located at 138KV side of the transformer)1.2.7.1Circuit BreakersPower Circuit BreakersBy definition, a circuit breaker is a device that closes and interrupts (opens) an electric circuit between separable contacts under both load and fault conditions. The rating of a circuit breaker is a summary of its characteristics that identifies its application on an electric system, its performance capabilities, and its adaptability. This summary of characteristics is given principally in terms of voltages, currents, and time as described in the rating tables.This substation will use three 138KV breakers in a ring bus configuration, this ring bus will have two exit lines, and a single 138:69KV transformer line exit with breaker. Column A represents my calculations, scope contents, and IEEE Standards. Column B represents the data in breaker’s data sheet. 1.2.7.1Circuit Breakers (Located at 138KV side of the transformer)ParametersColumn A / RatingsColumn B / RatingsMaximum continuous current2000 A (Scope)3000 AShort circuit interrupting current20000 A (Scope)40000 AAsymmetrical Current 33953.997, X/R=11.44417 (Scope, appendix calculations)Maximum voltage145 KV (Scope)145 KVNominal voltage138 KV (Scope)138 KVBasic Impulse Level (BIL)550 KV (Scope)750 KVInterrupting time3 Cycles ( IEEE C37.04-1999 )3 CyclesReclosing time At least 135 mS (IEEE C37.010-1999 )135 mSVoltage range factor K1.01.0TypeSF6 gas, Dead tank (Scope)SF6 gas, Dead tankQuantity3 (Scope)3Provisions: Six (6) sets of 1200:5 Multi Ratio Current Transformer, Rating Factor(R.F.) 2.5, C800 accuracy class (two (2) CT’s per bushing), (Scope)Porcelain bushings (ANSI 70 gray) rated: 750 kV BIL (data sheet)Paint color will be ANSI-70 Gray.Operating mechanism will be motor charged spring-springSingle tank-mounted gas density monitor and pressure gauge.Dual trip coils with trip coil 1, trip coil 2 and close coil each on a separately fused 125V DC supply. Fuses at the breaker will be replaced with slugs in the field.Breaker position indicator.Current transformers secondary will be grounded in control panelCircuit Breaker (Located at 69KV side of the transformer)ParametersColumn A / RatingsColumn B / RatingsMaximum continuous current2000 A (Scope)3000 AShort circuit interrupting current20000 A (Scope)40000 AAsymmetrical Current 33953.997, X/R=11.44417 (Scope, appendix calculation)Maximum voltage72.5 KV (Scope)72.5 KVNominal voltage69 KV (Scope)69 KVBasic Impulse Level (BIL)350 KV (Scope)350 KVInterrupting time3 Cycles ( IEEE C37.04-1999 )3 CyclesReclosing time At least 135 mS (IEEE C37.010-1999 )135 mSVoltage range factor K1.01.0TypeSF6 gas, Dead tank (Scope)SF6 gas, Dead tankQuantity1 (Scope)1Provisions: Six (6) sets of 1200:5 Multi Ratio Current Transformer, Rating Factor(R.F.) 2.5, C800 accuracy class (two (2) CT’s per bushing), (Scope)Porcelain bushings (ANSI 70 gray) rated: 350 kV BIL (data sheet)Paint color will be ANSI-70 Gray.Operating mechanism will be motor charged spring-springSingle tank-mounted gas density monitor and pressure gauge.Dual trip coils with trip coil 1, trip coil 2 and close coil each on a separately fused 125V DC supply. Fuses at the breaker will be replaced with slugs in the field.Breaker position indicator.Current transformers secondary will be grounded in control panelDisconnect SwitchesAlmost every transmission line or major equipment in a substation has associated with a disconnect switch as a means of completely isolating it from other energized elements as a prudent means of insuring safety by preventing accidental energization. These simple switches, called disconnects, or disconnecting switches, are usually installed on both sides of the equipment or line upon which work is to be done.Disconnect switches should not be operated while the circuit in which they are connected is energized, but only after the circuit is de-energized. As a further precaution, they may be opened by means of an insulated stick that helps the operator keep a distance from the switch if load breaking modifications have been made to the switch.Two types of disconnect switches are used in this substation, Horizontally mounted Vertical Switches for 138KV circuit breakers, and VEE switches for 69KV breakers.1.2.7.2Disconnect SwitchesAlmost every transmission line or major equipment in a substation has associated with a disconnect switch as a means of completely isolating it from other energized elements as a prudent means of insuring safety by preventing accidental energization. These simple switches, called disconnects, or disconnecting switches, are usually installed on both sides of the equipment or line upon which work is to be done.Disconnect switches should not be operated while the circuit in which they are connected is energized, but only after the circuit is deenergized. As a further precaution, they may be opened by means of an insulated stick that helps the operator keep a distance from the switch if load breaking modifications have been made to the switch.Two types of disconnect switches are used in this substation, Horizontally mounted Vertical Switches for 138KV circuit breakers, and VEE switches for 69KV breakers.\Disconnect Switches (Located onDisconnect Switches (Located on both sides of 138KV breakers) both sides of 138KV breakers)ParametersRatingsTypeHorizontally mounted Vertical BreakMaximum continuous current2000 AShort circuit interrupting current20000 AMaximum voltage145 KVNominal voltage138 KVBasic Impulse Level (BIL)550 KVOperatorManual with linkages for 3 Phase OperationQuantity18Disconnect Switches (Located on both sides of 69KV breaker)ParametersRatingsTypeVEE switchMaximum continuous current2000 AShort circuit interrupting current20000 AMaximum voltage72.5 KVNominal voltage69 KVBasic Impulse Level (BIL)350 KVOperatormanualQuantity6Disconnect Switch for Control Power (this switch I just a 1Single Pphase Sswitch)ParametersRatingsTypeVEE switchMaximum continuous current2000 AShort circuit interrupting current20000 AMaximum voltage72.5 KVNominal voltage69 KVBasic Impulse Level (BIL)350 KVOperatormanualQuantity1, Provisions:No current interrupting or energized closing capabilitiesInsulators: High strength station post, porcelain Motor Operated Air Break (MOAB) SwitchMotor operated switch will be installed at the high side of the transformer (138KV) and before two 138KV circuit breakers. Logic for the MOAB is that when a fault happens in transformer, two 138KV breakers will be tripped, then upon successful breaker operation, the MOAB will open, and when it’s confirmed open, the two breakers will be reclosed thereby returning the ring bus to normal. The size of DC motor size is to be determined later. We are also going to have a limit switch on the MOAB operating shaft that will let the motor run until the disconnect switch is properly opened vertically ( 90 degree ), or properly closed horizontally (0 degree).1.2.7.3Motor Operated Air Break (MOAB) SwitchMotor operated switch will be installed at the high side of the transformer (138KV) and before two 138KV circuit breakers. Logic for the MOAB is that when a fault happens in transformer, two 138KV breakers will be tripped, then upon successful breaker operation, the MOAB will open, and when it’s confirmed open, the two breakers will be reclosed thereby returning the ring bus to normal. The size of DC motor size is to be determined later. We are also going to have a limit switch on the MOAB operating shaft that will let the motor run until the disconnect switch is properly opened vertically ( 90 degree ), or properly closed horizontally (0 degree). ParametersRatingsTypeHorizontally mounted Vertical BreakMaximum continuous current2000 AShort circuit interrupting current20000 AMaximum voltage145 KVNominal voltage138 KVBasic Impulse Level (BIL)550 KVOperatorManual with linkages for 3 Phase Operation with DC motor (details To Be Determined later)Quantity11.2.7.43Coupling Capacitor Voltage Transformers1.2.7.4Surge ArrestersSurge arresters are designed to minimize the effects of transient voltage spikes due to switching operations and lightning strikes of currents less than Is. When the Maximum Continuous Operating Voltage (MCOV) is exceeded, the arrester reduces its internal impedance from line to ground. This action draws current through the surge impedance thereby reducing the magnitude of the wave voltage. As the voltage decreases back to MCOV, the internal impedance of the arrester increases minimizing the current flowing through it. This response protects the substation equipment from damaging voltage surges while allowing the substation to still operate. The surge arresters will be installed on both sides of the power transformer and each location where a transmission line enters and connects to the substation bus work. The surge arresters connected to the incoming lines shall have inverted skirting to prevent the accumulation of debris and possible shorting around the arrester. 138kV Surge Arrester RatingsType: Siemens 3EL2 180-2PM31-4NHSArrester rating (duty cycle): 108 kVArrester rating (MCOV): 84 kV Class: StationLocation: Outdoor, vertical mounting, porcelain shell, ANSI 70 gray color69kV Surge Arrester RatingsType: Siemens 3EL1 060-1PH21-4YH5Arrester rating (duty cycle): 60 kVArrester rating (MCOV): 48 kV Class: StationLocation: Outdoor, vertical mounting, porcelain shell, ANSI 70 gray color1.2.7.5Current TransformersPower TransformerThe primary function of a transformer is to take one nominal voltage and "transform" it into another nominal voltage.1.2.7.6.1 Rating and Technical DetailsThe transformer shall have the following ratings as found in Table x.1Table x.1Design Standard:ANSI Std C57.12.10-2010Transformer TypeOil immersed, conservator design, autotransformerNo. of PhasesThreeFrequency60 HzNominal Primary Voltage - HV140 kVNominal Secondary Voltage - LV72 kVNominal Tertiary - TV13.2 kVInsulation Level Winding: HVLVTVNeutral550 kV350 kV150 kV150 kVInsulation Level Bushings:HVLVTVNeutral650 kV350 kV150 kV150 kVLocation: Indoor/OutdoorOutdoorType of CoolingONAN / ONAFRated Capacity100 / 134 MVAConnection: HV-LV TVWye - Delta Earthing:HV/LVSolidly grounded neutralImpedance5.6%De-energized Tap Changer (DETC) HV:4 Position / 3 steps @ 3.57%4321Volts kVCurrent At100 MVA134 MVA140135130125412428444462553573595619Altitude< 1000 m (3300 ft)Ambient TemperatureHiLoAverage Rise Above Ambient 40 oC-20 oC 65 oCTank FinishNonmetallic pigment1.2.7.6.2 Tank ConstructionThe tank shall be sufficiently constructed to withstand strain caused by transportation by rail, road, or sea. It will be designed, along with the radiators , for 14.7 PSI and full vacuum filling. The sides of the cover will be slopped for water runoff and covered with a non-skid coating. The interior will be painted white. The following construction considerations will have location referenced to Figure 1 of IEEE c57.12.10-2010 as shown below.174307531750Figure 1 - "Accessories" IEEE c57.12.10-20101.2.7.6.3 Operation and Status ComponentsThe DETC operating handle shall be brought out through the side of the tank in segment 4. The Handle shall have the ability to be padlocked, and a visual indication of handle position should be visible without unlocking. Visual indication will be clearly marked with Arabic numerals in sequence with "4" being assigned to the maximum ratio. The DETC warning plate will be mounted directly above operating handle. A magnetic oil level gauge with vertical face will be located in segment 1 on both the tank and conservator. The gauges will be of dark-face and high contrast markings and dial. The dimensions will be of those found in IEEE std c57.12.10-2010 section 5.1.2. Extremes will be labeled "HI-LO" and a permanent marking of 25 oC with 10 oC divisions will be implemented. To measure top-oil temperature, a liquid temperature gauge will be located in segment 1. The display will be analog with a range from 0 to 120 oC. Faceplate will be dark-face with high contrast pointer and markings. A sensor that detects ambient temperature will be located in segment 4 just below the transformer monitoring cabinet. Under load, transformer oil increases in temperature and thus volume which causes the rubber bag in the conservator to expand. This expansion pushes air out. Conversely, the opposite happens when the oil's volume decreases. This process is called breathing. The air that is breathed in contains moisture that needs to be dehydrated since moisture compromises insulation. To remove moisture, a silica gel breather will be installed in segment 2.1.2.7.6.4 Valves and Safety ComponentsThe transformer is a sealed device and can become subject to excessive pressure during internal faults. To discharge overpressure, a pressure relief valve will be mounted on the top of the transformer that is rated at 10 PSI. During transformer faults, hydrogen is produced. To aid in early detection, a dissolved hydrogen & water IED (gas analyzer) will be installed which monitors hydrogen levels. The IED also monitors moisture levels to insure premature deterioration of insulation doesn't occur. The dissolved hydrogen & water monitor uses two compression fittings to supply oil (top-oil valve) and then return it (bottom valve). Both ball valves are next to the monitor which will be in segment 1 and are 0.5" in diameter. To reduce shipping weight, the transformer will be shipped without oil. To prevent the entrance of moisture during transit, the transformer will be filled with dry air under pressure. A 0.5" DIA globe valve will be installed in segment 1 for this purpose. For quickly removing oil, a 3" DIA ball valve will be installed on top of the transformer between H2 and H3 for connecting to a vacuum (brass fitting). To fill the conservator with oil, a 1" DIA globe valve will be installed on the top of the conservator. At the bottom of the conservator, the same type of globe valve will be used to drain oil from the conservator. A bleeder valve will be installed on the top of conservator to release air during the filling process and breathing due to fluctuations in oil volume. To isolate the oil from the conservator from the oil in the main tank, a 3" DIA butterfly shutoff valve will be installed in the middle of the connecting pipe. A 1" DIA connection valve will be installed on top of the Silica Gel Breather in segment 2.A sudden pressure relay allows for early detection of faults that occur inside the transformer. The type used will be an under fluid sudden pressure relay which reacts to rapidly changing pressure from 10 kPa/s to 38 kPa/s. Alarm contacts will be in accordance with 5.1.10 and 5.1.11 found in IEEE c57.12.10-2010. A 2.5" DIA gate valve will be installed directly above the sudden pressure relay. A Buchholz relay will be installed between the conservator and tank which allows cheap, early direction of slow developing faults inside the transformer. During faults and overloads, the insulating oil will decompose which produces gas that accumulates at the top of the relay forcing oil down. A float system initiates an alarm. A gas sampling valve with 5/16" DIA piping for use with the Buchholz relay will be located in segment 2 and a gas accumulation pipe of 1.5" in diameter will be run across the top of the transformer. 1.2.7.6.5 GroundingThe transformer is the most expensive piece of equipment in the substation, so proper grounding is important to protect the investment, as well as ensuring the safety of others during a fault. A 4 x 0.25 inch copper bar will run down the side of the transformer in segment 1, along with a 2 x 0.25 inch copper bar to provide a ground path for the bushings. The larger bar is for the neutral of the high and low side bushings, whereas the smaller bar is for the tertiary. The larger bar will have 2-4/0 AWG cables on each end and the smaller bar will have a single 4/0 AWG cable on each end. Grounding will terminate to 2 stainless steel grounding pads of NEMA type 2. 1.2.7.6.6 TransportationLifting, moving, and jacking facilities will be such that the ratio of ultimate stress on the material to the working stress (safety factor) is 5 when suspended and 2 or greater for pulling applications. The transformer will be shipped without oil to reduce weight. To keep moisture out, the transformer will be filled with dry air under pressure. To keep the transformer under pressure during transit, dry air canisters will be mounted on the side of the transformer in segment 4. Just above the dry air canisters will be an impact recorder to indicate any unusual impacts. The center of gravity for both dry air and filled with oil will be labeled on the side of the transformer in segment 4. The transformer's base shall be suitable for both skidding and rolling. For shipping, 4 lugs located at all 4 corners of the transformers will be used. For lifting the entire transformer, 4 lugs will be provided (2 in segment 2 & 2 in segment 4). In addition, 4 separate lugs will be provided on the core and coil assembly for lifting from the tank. For jacking the transformer, 4 jacking plates will be located on all 4 corners of the transformer and have a surface size of 17.72" x 12.99".1.2.7.6.7 Surge Arrester MountsSurge arresters provide protection against transient overvoltages like those from lightning strikes. When an overvoltage is detected the arrester conducts and discharges the surge to ground. Once the surge is reduced to a safe point, the arrester stops conducting and the circuit returns to normal. The maximum amount of voltage that can occur across the terminals of the surge arrester is called the duty cycle. The transformer will have 3 HV arresters and 3 LV arresters. The high side has a duty cycle of 108 kV and the low side has a duty cycle of 60 kV. The maximum amount of voltage that the arrester is designed to operate with and not conduct is called the maximum continuous operating voltage (MCOV). For the high side, the surge arresters are rated for 84 kV and the low side is 48 kV. 1.2.7.6.8 Transformer BushingsBushings are how the transformer interfaces with the rest of the substation. They are the insulators that the conductors pass in and out of the transformer. There will be 3 HV bushings, 3 LV bushings, 2 tertiary bushings, and a neutral bushing. All bushings will ship with the transformer. The insulation material of choice will be largely composite with the HV bushings being the only porcelain insulated bushings. The HV bushing is rated for a nominal voltage of 138 kV and a nominal current of 1200 A. The rest of the bushings are rated for a nominal current of 2000 A with the LV bushing being 69 kV nominal voltage and the tertiary being 150 kV nominal voltage. The BIL ratings can be found in the table of section 4.3x.1 and are as follows HV = 650 kV, LV = 350 kV, and the neutral and tertiary = 150 kV.1.2.7.6.9 De-energized Tap Changer (DETC)The DETC allows for a de-energized changing of nominal voltage ranging from 140 kV (position 4) to 125 kV (position 1) on the HV side (essentially a 4 position switch of a 4% reduction of voltage). The DETC is usually set seasonally to better match the incoming voltage to the load during higher or lower demands throughout the year. The switch and warning label can be found in segment 4. 1.2.7.6.10 ConservatorThe conservator tank is what keeps the transformer flooded with oil. Inside the tank is a diaphragm (rubber bag) which reacts to changes in volume of the oil. It will be located above the transformer by means of a supporting bracket in segment 2. The tank will have 2 lifting lugs for removal. 1.2.7.6.11 CoolingAlthough transformers are extremely efficient, the large currents that they are capable of generatinges a lot of heat that needs to be taken from the oil to maintain life expectancy. If the oil is allowed to get too hot, the insulation inside would deteriorate much more rapidly. Radiators are used to cool transformers along with other peripherals such as pumps and fans.This transformer's design will implement 2 stages of cooling and use the IEC designations which are found below.ONAN - Oil Natural - Air Natural ONAF - Oil Natural - Air Forced The first stage of cooling will be ONAN which is natural convection of oil through the radiator. This stage will allot 100 MVA. The next stage will be ONAF which will utilize fans to force air across the radiator. This bay of fans allows an increase of load and thus a 34% increase in MVA resulting in 134 MVA. The radiator and fans will be located in segment 3.1.2.7.6.12 FansThe fan motors will be 240 V, 60 Hz, single-phase, without centrifugal switch and shall be individually fused. AC power will be provided from auxiliary transformer inside substation. The fan motors will 1/6 HP at 1140 RPM.1.2.7.6.13 ControlsThe control cabinet will be located in segment 1 and have (2) 7 x 21.25 inch openings on the bottom for conduit. 1.2.7.6.14 NoiseCore vibrations inside the transformer coupled with the cooling fans will generate undesirable noise at a certain SPL (Sound Pressure Level). The substation’s location does not pose concern of noise complaints. 1.2.7.6.15 Tertiary WindingThe tertiary winding in this design is only for mitigation of triplen harmonics and to introduce neutral stability which addresses the two biggest problems with Wye to Wye transformers. It will not be used for power in the substation. 1.2.7.6.16 NeutralsThe neutral of both the high side Wye and low side Wye will be solidly grounded through the use of copper bus bars and 4/0 AWG wire as noted in the section xgrounding section (4.3.5).Coupling Capacitor Voltage TransformersCoupling capacitor voltage transformers or CCVT's are transformers that take the large voltages in the substation and transform them to a smaller magnitude without a phase change. Single Phase CCVT Ratings:Primary voltage:138/√3 kVSecondary voltage:69/√3 kVRatio:2500/4500:1Accuracy class:X1-X2-X3 Winding - 0.3 W, X, Y, Z, & ZZ BurdenY1-Y2-Y3 Winding - 0.3 W, X, Y, Z, & ZZ BurdenBasic Impulse Level (BIL):550 kVTotal Capacitance:greater than 3000 pFProvisions:Porcelain bushing (ANSI 70 gray).Tank paint color will be ANSI-70 VTs will be supplied with NEMA standard 4-hole pads on HV bushing terminal.Carrier accessories required on all CCVTs. 1.2.8Lightning ShieldingLightning shielding is a system designed to protect the substation equipment and bus work from lightning strikes and associated surges. The system consists of masts located on top of structural bus supports, or mounted directly on the ground. These masts are electrically connected directly to the grounding grid of the substation. This is to minimize the impedance the lightning stroke current will see, diverting it to the masts and from other substation equipment.This lightning shielding system will be designed using the Rolling Sphere method per IEEE 998-2012. This method involves a sphere, of radius S, and "rolling" it around the lightning masts. Any equipment located under the tent created by the rolling sphere is assumed to be protected. However, there are no 100% effective means of lightning protection.Rolling Sphere Example1.2.8.1 DesignS is the strike distance (in feet) of the last stepped leader of a lightning strike. This distance becomes the radius of the sphere. To determine sphere radius S, several aspects of the substation design must be considered. The allowable surge current (Is) determines the magnitude of stroke current the substation can endure without failure due to flashover.S is the strike distance (in feet) of the last stepped leader of a lightning strike. This distance becomes the radius of the sphere. To determine sphere radius S, several aspects of the substation design must be considered. The allowable surge current (Is) determines the magnitude of stroke current the substation can endure without failure due to flashover. Surge impedance (Zs) is the impedance of the equipment, that the surge current is passing through, to ground. Surge current and surge impedance can be determined using the following equations:Zs (Ω) = 60*ln(2*he/rc)Is (kA) = 2.2*BIL/Zswhere "he" is the height, in feet, of the equipment the surge current is flowing through; "rc" is the radius of the conductor, not including insulation; BIL is the Basic Impulse Level. From this, the sphere radius, S, can be calculated, according to IEEE 998-2012 equation 17.where he is the height, in feet, of the equipment the surge current is flowing through; rc is the radius of the conductor, not including insulation; BIL is the Basic Impulse Level. From this, the sphere radius, S, can be calculated, according to IEEE 998-2012 equation 17.S (feet) = 26.25*Is^0.65This sphere is then rolled around, while keeping constant contact with the mast. If any piece of equipment passes into the sphere, it is not protected and more shielding must be added for adequate protection.1.2.8.2 MastsThere will be six (6) 65' masts and two (2) 49' masts installed. The 65' masts are for protection of the 138kV system and the 49' masts will protect the 69kV system and control house structure. These masts will be connected directly to the ground grid. 1.2.8.3 InstallationLightning masts can be installed on top of equipment or bus supporting structures, or they can be mounted as a stand-alone on a foundation on the ground. Masts mounted to support structures allow for lightning protection inside the equipment footprint, while satisfying BIL requirements. Two of the 65' masts will be installed on top of the main supporting A-frame structure. The remaining masts will be installed as standalones at locations specified by calculations in accordance with IEEE 998-2012. Both methods of installation require the mast to be electrically connected to the substation ground grid. This is accomplished by connecting a copper cable of appropriate size from the mast to the ground grid. THIS SENTENCE DOES NOT MAKE SENSE This cable will be connected to the ground grid via , to prevent contamination between the conductors that could cause a rise in impedance.Lightning masts can be installed on top of equipment or bus supporting structures, or they can be mounted as a stand-alone on a foundation on the ground. Masts mounted to support structures allow for lightning protection inside the equipment footprint, while satisfying BIL requirements. Two of the 65' masts will be installed on top of the main supporting A-frame structure. The remaining masts will be installed as standalones at locations specified by calculations in accordance with IEEE 998-2012. Both methods of installation require the mast to be electrically connected to the substation ground grid. This is accomplished by connecting a copper cable of appropriate size from the mast to the ground grid. THIS SENTENCE DOES NOT MAKE SENSE This cable will be connected to the ground grid via to prevent contamination between the conductors that could cause a rise in impedance. 1.2.9Switchyard Grounding1.2.10Switchyard Raceway Systems1.2.11Switchyard Lighting1.2.12Control Enclosure Electrical Design1.2.12.1Conductor Raceway Design1.2.12.1.1Conduit and Wireway1.2.12.2Grounding1.2.12.3Lighting1.2.13Station Service Design1.2.13.1AC Station Service1.2.13.2DC Station ServiceThe 125V DC system will consist of one battery and two chargers. Each charger and the battery will be capable of providing emergency operation and continuous control power for the substation facility and breaker operating power at the end of the 8 hour duty cycle. The battery will be supplied with a manual maintenance switch to disconnect the DC distribution panel from the battery. In order to calculate minimum Amp-hour output for battery and it’s charger it is necessary to add the amperages needed for all dc lamps in substation, relays and panel indicating lamps, communications, four simultaneous breaker operation and the current to be consumed by the DC motor of the motor operated air break (MOAB). All the calculations for battery sizing will be based on the IEEE 485-1997. The battery will be sized for a minimum Amp-hour output 470 with the following criteria:Nominal battery voltage:: 125V DCNumber of cells:: 60Emergency operating time:: 8 hroursMinimum cell voltage:: 1.75VLowest expected electrolyte temperature: 68? FType: Lead-calciumAging Factor: 25%Design Margin:: 10%The charger will be sized for a minimum Ampere output 40 with the following criteria: Input voltage: 2240 volts -, 1- phaseOutput voltage: Adjustable from 125 to 140 volts125 - 140 VEqualize timer: 0 - to 72 hrhoursRecharge time at design load: eight hours248 hr5 Protective Relaying5.1 PurposeThe objectives of protective relaying are to minimize the effects of system disturbances and to minimize the possible damage to power system equipment. Relay protection for the larger size transformers usually includes sudden pressure relays, differential relays, overcurrent relays or and ground overcurrent relays. Sudden pressure relays are the primary relay protection on a transformer. Protective RelayingPurposeThe objectives of protective relaying are to minimize the effects of system disturbances and to minimize the possible damage to power system equipment. Relay protection for the larger size transformers usually includes sudden pressure relays, differential relays, overcurrent relays or and ground overcurrent relays. Sudden pressure relays are the primary relay protection on a transformer.5.2 Relay Panel SpecificationsThe control and relay panels will be designed according to the following criteria:NEMA standard vertical switchboardPanel construction: 1/8 in ” cold rolled steelRelay panel width: 30 in”Breaker control panel width: 30 in”Panel height: 90 in”Interior color:: High Gloss WhiteExterior color: ANSI 70 light grayControl leads: No. 12 AWG stranded copper, 600 V, SIS typeCurrent and potential leads: No. 10 AWG sstranded copper, 600 V, SIS typeTerminal blocks: Similar to 12-point Marathon 1600 seriesGround bus: ?" ” x 2"” CcopperAll relays must have the following:Access to back of Schweitzer relays is required for PC connection.Appropriate test/disconnect switches are required to provide connections for relay testing and isolation.5.3 Relay SpecificationsAll relay schemes shall be suitable for power line carrier connections. All relays shall incorporate event recorders, in addition, SCADA (control, indication and metering) will be required for the new equipment. This will include SCADA control (trip and close) of all circuit breakers, breaker status (52a) indication as well as additional SCADA indication and metering as indicated in the following: 138 kV Breaker B1 (East Bottoms/West Bottoms) Breaker Failure-to-Trip Relay Schweitzer SEL-035210325HXX4XX, (BFR/B1) Breaker Failure relay, suitable for use at 125V DC. To be used for 138 kV Breaker B1 failure-to-trip protection.Electroswitch series 24 Lock-Out Relay (86BF/B1)Electroswitch series 24 switch to be used as a Failure to Trip cutoff switch (FT/CO). This switch shall be utilized to disable the Failure to Trip relaying for testing and maintenance. 138 kV Breaker B1 (East Bottoms/West Bottoms) Automatic Reclosing RelaySchweitzer SEL-0351A00H23554X, (79/B1) Breaker Auto-reclosing relay, suitable for use at 125V DC. To be used for 138 kV Breaker B1 Automatic Reclosing.138 kV Breaker B2 (East Bottoms/TR) Breaker Failure-to-Trip RelaySchweitzer SEL-035210325HXX4XX, (BFR/B2) Breaker Failure relay, suitable for use at 125V DC. To be used for 138 kV Breaker B2 failure-to-trip protection.Electroswitch Series 24 Lock-Out Relay (86BF/B2)Electroswitch series 24 switch to be used as a Failure to Trip cutoff switch (FT/CO). This switch shall be utilized to disable the Failure to Trip relaying for testing and maintenance.138 kV Breaker B3 (TR /West Bottoms) Breaker Failure-to-Trip RelaySchweitzer SEL-035210325HXX4XX, (BFR/B3) Breaker Failure relay, suitable for use at 125V DC. To be used for 138 kV Breaker B3 failure-to-trip protection.Electroswitch Series 24 Lock-Out Relay (86BF/B3)Electroswitch series 24 switch to be used as a Failure to Trip cutoff switch (FT/CO). This switch shall be utilized to disable the Failure to Trip relaying for testing and maintenance.138 kV East Bottoms Line ExitSchweitzer SEL-32111-4256-HNB3X4, (PR/EB) phase distance relay and ground directional overcurrent relay with fault locator and fast meter communications. New to be used to provide phase and ground protection. SCADA remote sub unknown.Schweitzer SEL-311B-00H24254XX, (BU/EB) phase distance relay and ground directional overcurrent relay. New to be used to provide one set of phase and ground protection. SCADA remote sub unknown.138 kV West Bottoms Line ExitSchweitzer SEL-311L1H-3254-XXXX, (PR/WB) current differential relay and phase and ground distance relay and ground directional overcurrent relay. New to be used to provide current differential plus phase and ground primary protection. SCADA remote sub unknown.Connect West Bottoms fiber optic channel to the fiber port on the back of the relay.Install a Line Differential Cut-Off Switch for primary line relay which shall provide and input into the SEL-311L.Schweitzer SEL-32111-4256-HNB3X4, (BU/WB) phase distance relay and ground directional overcurrent relay with fault locator and fast meter communications. New to be used to provide phase and ground protection. SCADA remote sub unknown.138/69kV Transformer (TR) Differential RelayingSchweitzer “SEL-0587103X5X1” (87T/TR) Current Differential relay to be used as primary transformer low impedance differential protection. Appropriate test switches are required to provide connections for relay testing and isolation.Note: LOR 86TX/TR is reset by a 89b contact from the high side MOAB (A1). This is to allow the 138kV breaker to be closed after the TR MOAB is open.138/69kV Transformer (TR) 138kV Lead Differential RelayingSchweitzer “SEL-0587Z0X325H12XX” high impedance bus differential relay with high energy (2) clamping MOVs. Horizontal rack mount. New, to be used for TR 138 kV bus differential protection.Electroswitch “LOR”, spring operated, Manual reset, multi-stage auxiliary tripping relay. New, to be used with the above FILLIN \* MERGEFORMAT SEL 587Z relay for TR 138 kV leads/bus auxiliary.138/69kV Transformer (TR) Overall Differential RelayingSchweitzer “SEL-038750-4X5HXX4XX” (87OA/TR) current differential relay. New, to be used for TR overall differential protection.Electroswitch “LOR”, (86OA/TR) spring operated, Manual reset, multi-stage auxiliary tripping relay. New, to be used with the above FILLIN \* MERGEFORMAT SEL 587 relay for TR differential relaying.138/69kV Transformer (TR) Ground Overcurrent ProtectionSchweitzer “SEL-055100-3X5X1X,” overcurrent relay, with metering, suitable for use at 125V DC. New, to be used for TR tertiary ground protection. 5A Phase input, 5A neutral.Series the Phase A and IN CT circuits.ABB “AR” aux tripping relay. New, to be used with the above FILLIN \* MERGEFORMAT SEL 551 relay for TR ground overcurrent.6 Communication6.1 Communications Equipment138 kV East Bottoms Line ExitRFL 9785 65-156 kHz frequency range 10 watt, 1000 Hz bandwidth, carrier relaying transmitter-receiver assembly complete with keying unit, checkback module and auxiliary power supply at 125V DC. To be tuned to 142.5 kHz. New, to be used for DCB communications on the East Bottoms 138kV exit.Monitor the checkback failure alarm by SCADA alarm point.Include hardware necessary to capture sequence of events.No voice functions necessary.138kV Single Frequency Wave Trap for use at 142.5 kHz, minimum 2000A continuous. New, to be used for 138kV East Bottoms DCB communications on the East Bottoms circuit exit. Unit shall be coupled to phase 3.Single Frequency Resonant Line Tuner. New, to be used for 138kV East Bottoms DCB communication on East Bottoms circuit exit. Unit shall be tuned to 142.5 kHz and be used with phase 3 wave trap.6.2 Additional CommunicationGeneral communications one line via LAN/WAN is supplied, specific models and details to be determined by utility. (see Appendix) Substation groundingIntroductionThe grounding grid provides a common ground for the electrical equipment as well all the metallic structures in the substation. Effective Grounding system design is important as it deals with personnel safety and protection of electrical equipment. Earth Fault gives rise to potential gradient within and around the substation. This voltage gradient should not exceed the tolerable human body limit. Substation grounding grid design therefore requires calculating of parameters related to earth and grounding with a great concern for the safety of the persons who may come under the influence of the potential gradient due to severe earth faults. Reduction of the substations ground grid total’s resistance also minimizes the effect of the ground potential rise to elements connected to the substations metallically but not in the fault current path. General RequirementsA ground grid design has two primary objectives:To provide means for carrying electric currents into the earth under normal and fault conditions to maintain continuity of service and low impedance path for ground fault such that the equipment ratings are not comprised.To protect personnel within and in the vicinity of the substation, from the dangers of electric shock during a ground fault.In order to properly plan and design the grounding grid, the following parameters are calculated or defined: maximum fault current, grid resistance, grid current, safe touch and step voltages, ground potential rise, as well as expected touch and step voltage levels.Design SpecificationThe grounding system grid shall consist of a network of bare conductors, the mesh buried in the earth to provide grounding connections to equipment ground terminals, equipment housing, and structures to limit the maximum possible shock current during fault conditions to safe values. If the determined step and touch voltages are below the maximum values for touch and step then the design is considered adequate.The ground grid should encompass all of the area within the substation fence and extend at least 3.0 feet outside the substation fence. The maximum single phase grid current during fault conditions has been determined to be: 20 kA.The tolerable touch and step voltages are to be determined using WinIGS for a shock duration of 0.25 seconds and must conform to IEEE Std80 (2000) safety standards.The equipment and grid ground conductor should be 4/0 soft drawn bare copper.The ground grid should consist of horizontal conductors placed in the ground to produce a square mesh. This can be visualized by a checkerboard pattern.Every grid conductor intersection should be bonded using exothermic welds.Vertical ground rods should be placed at grid corners and at junction points along the perimeter of the grid. Ground rods should be installed near major equipment, especially surge arresters. Vertical ground rods were specified to be 5/8 inch diameter and 10 foot long copper clad steel.All hand-crank switches require a 4 foot x 6 foot safety mat that is electrically connected to the switch and is placed directly below the switch crank. This will essentially prevent a potential gradient between the switch and the grid should a fault occur during switch operation.The entire area inside the fence and including a minimum of 3.5 feet outside the fence should be covered in 6 inches of crushed rock, possessing an approximate resistivity of 3,000 ohm-meters.7.1 Substation grounding:7.1.1 Introduction:The grounding grid provides a common ground for the electrical equipment as well all the metallic structures in the substation. Effective Grounding system design is important as it deals with personnel safety and protection of electrical equipment. Earth Fault gives rise to potential gradient within and around the substation. This voltage gradient should not exceed the tolerable human body limit. Substation grounding grid design therefore requires calculating of parameters related to earth and grounding with a great concern for the safety of the persons who may come under the influence of the potential gradient due to severe earth faults. Reduction of the substations ground grid total’s resistance also minimizes the effect of the ground potential rise to elements connected to the substations metallically but not in the fault current path. 7.1.2 General Requirements: A ground grid design has two primary objectives:To provide means for carrying electric currents into the earth under normal and fault conditions to maintain continuity of service and low impedance path for ground fault such that the equipment ratings are not comprised.To protect personnel within and in the vicinity of the substation, from the dangers of electric shock during a ground fault.In order to properly plan and design the grounding grid, the following parameters are calculated or defined: maximum fault current, grid resistance, grid current, safe touch and step voltages, ground potential rise, as well as expected touch and step voltage levels.7.1.3 Design Specification:The grounding system grid shall consist of a network of bare conductors, the mesh buried in the earth to provide grounding connections to equipment ground terminals, equipment housing, and structures to limit the maximum possible shock current during fault conditions to safe values. If the determined step and touch voltages are below the maximum values for touch and step then the design is considered adequate.The ground grid should encompass all of the area within the substation fence and extend at least 3.0 feet outside the substation fence. The maximum single phase grid current during fault conditions has been determined to be: 20 kA.The tolerable touch and step voltages are to be determined using WinIGS for a shock duration of 0.25 seconds and must conform to IEEE Std80 (2000) safety standards.The equipment and grid ground conductor should be 4/0 soft drawn bare copper.The ground grid should consist of horizontal conductors placed in the ground to produce a square mesh. This can be visualized by a checkerboard pattern.Every grid conductor intersection should be bonded using exothermic welds.Vertical ground rods should be placed at grid corners and at junction points along the perimeter of the grid. Ground rods should be installed near major equipment, especially surge arresters. Vertical ground rods were specified to be 5/8 inch diameter and 10 foot long copper clad steel.All hand-crank switches require a 4 foot x 6 foot safety mat that is electrically connected to the switch and is placed directly below the switch crank. This will essentially prevent a potential gradient between the switch and the grid should a fault occur during switch operation.The entire area inside the fence and including a minimum of 3.5 feet outside the fence should be covered in 6 inches of crushed rock, possessing an approximate resistivity of 3,000 ohm-meters.7.1.4 Design Criteria: The study shall be carried out in conformity with the design guidelines listed below and the computer software used for the design calculations shall take into account all of the factors listed:7.1.4.1 Soil Testing: Before the design process can begin, soil resistivity measurements should be taken at the substation site. These should be made at a number of places within the site. Substation sites where the soil may possess uniform resistivity throughout the entire area and to a considerable depth are seldom found. Typically, there are several layers, each having a different resistivity. Often, lateral changes also occur, but, in comparison to the vertical ones, these changes usually are more gradual. Make soil resistivity tests to determine if there are any important variations of resistivity with depth. The number of such readings taken should be greater where the variations are large, especially if some readings are so high as to suggest a possible safety problem.A number of measuring techniques are described in detail in IEEE Std. 81-1983. The Wenner four-pin method as shown in Figure 1 is the most commonly used technique. In brief, four probes are driven into the earth along a straight line, at equal distances a apart, driven to a depth b. The voltage between the two inner (potential) electrodes is then measured and divided by the current between the two outer (current) electrodes to give a value of resistance, R. The current tends to flow near the surface for the small probe spacing, whereas more of thecurrent penetrates deeper soils for large spacing. Thus, it is usually a reasonable approximation to assume that the resistivity measured for a given probe spacing a represents the apparent resistivity of the soil to a depth of a when soil layer resistivity contrasts are not excessive. A soil resistivity test has been accomplished starting at very small spacing “a” in order to determine upper layer characteristics and depth, the test results at different probe spacing are listed in table 1.0.790575-4445 Figure 1Soil Test Data:Upper layer resistivity calculated by computer software WinIGS = 320.14 ohms-metersUpper layer depth calculated by WinIGS = 4.01 metersLower layer resistivity = 48.17 ohms-meters7.1.4.2 Ground Fault Currents :When a substation bus or transmission line is faulted to ground, the flow of ground current in both magnitude and direction depends on the impedances of the various possible paths. The flow may be between portions of a substation ground grid, between the ground grid and surrounding earth, along connected overhead ground wires, or along a combination of all these paths.The relay engineer is interested in the current magnitudes for all system conditions and fault locations so that protective relays can be applied and coordinating settings made. The designer of the substation grounding system is interested primarily in the maximum amount of fault current expected to flow through the substation grid, especially that portion from or to remote earth, during the service lifetime of the installed design. The maximum fault current for this substation was determined to be 20kA.7.1.4.3 Fault Current Split Calculation.A fault current split calculation shall be carried out based on a circuit model of the high and low voltage power line systems connected to the substation, including the remote substations whose transformers contribute fault current, in order to correctly determine the fault current distribution between the substation grounding system and power line ground return conductors, such as neutral and shield wires. The circuit model shall properly account for overhead and buried circuit characteristics, including conductor impedances, inductive coupling between conductors, leakage and ground impedances. The fault current split calculation shall consider faults occurring not only within the substation but also on circuits outside the substation, in order to determine the worst case fault location. 7.1.4.4 Ground Conductor(Conductor Material)The two most commonly used materials for grounding in the United States are copper and copper-clad steel.CopperCopper is a common material used for grounding. Copper conductors, in addition to their high conductivity, have the advantage of being resistant to most underground corrosion because copper is cathodic with respect to most other metals that are likely to be buried in the vicinity. Thus copper will be used for the grounding grid mesh.Copper-Clad SteelCopper-clad steel is usually used for underground rods and occasionally for grounding grids, especially where theft is a problem. Use of copper, or to a lesser degree copper-clad steel, ensures that the integrity of an underground network will be maintained for years, so long as the conductors are of an adequate size and not damaged and the soil conditions are not corrosive to the material used. Other types of ground conductor materials are discussed in IEEE Std. 80.Ground Conductor Sizing (Ampacity Calculation)Compute the required grounding conductor size, such that the maximum anticipated fault current can be carried, with the worst case symmetrical transient offset magnitude and backup fault duration, without damaging the conductor, based on the methodology specified in IEEE Standard 80. The conductor size to be used for my grounding system was determined to be 4/0 soft drawn bare copper.7.1.4.5 Ground Conductor Sizing (Ampacity Calculation):Compute the required grounding conductor size, such that the maximum anticipated fault current can be carried, with the worst case symmetrical transient offset magnitude and backup fault duration, without damaging the conductor, based on the methodology specified in IEEE Standard 80. The conductor size to be used for my grounding system was determined to be 4/0 soft drawn bare copper.7.1.4.6 Connections From Equipment and Stricter to Grounding Grid: Careful attention needs to be applied to the connections of substation structures, equipment frames, and neutrals to the ground grid to realize the benefits of an effective ground grid system. Conductors of adequate ampacity and mechanical strength should be used for the connections between:1. All ground electrodes, such as grounding grids, rodbeds, ground wells, and, where applicable, metal, water, or gas pipes, water well casings, etc.2. All above-ground conductive metal parts that might accidentally become energized, such as metal structures, machine frames, metal housings of conventional or gas-insulated switchgear, transformer tanks, guards, etc. Also, conductive metal parts that might be at a different potential relative to other metal parts that have become energized should be bonded together, usually via the ground grid.3. All fault current sources such as surge arresters, capacitor banks or coupling capacitors, transformers, and, where appropriate, machine neutrals, lighting, and power circuits.Extra ground connections should be considered at all critical locations (such as at equipment neutrals, transformers, surge arrester grounds, operating handles and ground mats, etc.) To ensure an effective grounding capability even when one conductor is broken or a connection is improperly made. Do not assume equal division of currents between multiple ground connections.Oxidation or corrosion in the connection can create hot spots that can shorten the life ofthe connection. With the connection below grade, there is no visual way of knowingwhen the connection has failed. A properly installed exothermic connection is amolecular connection that eliminates the oxidation and corrosion in the connection andreduces the opportunity for hot spots.7.1.4.7 Addition of Surface Layer & Reduction Factor:Additional surface A thin layer of highly resistive protective surface material such as crushed rock (approximately 3000 ohm..m in resistivity) spread above the earth grade at a substation can greatly reduce the available shock current at a substation. The surface material increases the contact resistance between the soil and the feet of people in the substation. The surface material is 6 inches in depth and extends to 4 feet outside the substation fence, however it can vary between 0.08 to 0.15 meter (3 to 6 inches) in depth and extends 0.91 to 1.22 meters (3 to 4 feet) outside the substation fence. If the surface material does not extend outside the substation fence, then the touch voltage may become dangerously high.Reduction Factor CSTo be determined later. 7.1.5 Safety ConsiderationsUnderground fault conditions, the portion of fault current flowing between a substation ground grid and the surrounding earth, IG, will result in potential gradients within and around the substation. Unless proper precautions are taken in design, the maximum gradients present can result in a potential hazard to a person in or near the substation. In addition to the voltage magnitude of the local gradients, such things as duration of the current flow, impedances in its path, body resistance, physical condition of the person, and probability of contact all enter into the safety considerationsLoad and fault studies:Load and fault studies are done by our client Burns & McDonnell. Below is given a short definition of load and fault studies and their purposes. The Short Circuit Study provides the calculated information necessary to properly size the circuit breakers and fuses to successfully interrupt a short circuit, and as well as to determine the forces encountered in the substation due to these short circuit currents. This type of study tells what the maximum amount of fault current is available for particular type of fault(s). In addition, the Short Circuit Study will provide symmetrical and asymmetrical current values for the faults. A Load Study is the analysis of power availability and usage within a system. The study will determine the voltage regulation and maximum steady state current demands for the various pieces of equipment in the substation at both 138 and 69KV. 7.1.5.1 Tolerable Limits of Body Currents The most common physiological effects of electric current on the body, stated in order of increasing current magnitude, are perception, muscular contraction, unconsciousness, fibrillation of the heart, respiratory nerve blockage, and burning. The threshold of perception for the human body is about one milliampere at commercial (50 or 60 Hz) frequencies. Currents of 1 to 6 mA, often termed let-go currents, though unpleasant to sustain, generally do not impair the ability of a person holding an energized object to control his muscles and release it. Higher currents (about 9 to 25 mA) can result in painful situations and affect the muscles so that the energized object is difficult if not impossible to release. Still higher mA currents can affect breathing and may cause fatalities if duration (usually on the order of minutes) is long enough. Further current increases (about 60 mA and above) can result in ventricular fibrillation of the heart. Sixty mA is approximately the current drawn by a 7.5 watt 120 V lamp. Currents above the level for ventricular fibrillation can cause heart paralysis, inhibition of breathing, and burns.7.1.5.2 Touch and Step Voltage Limits. The tolerable touch and step voltages are the criteria that have to be met to ensure a safe design. The lower the maximum touch and step voltages, the more difficult it is to produce an adequate grid design. In most cases the tolerable touch voltage will be the limiting factor. Touch & Step tolerable safety limits were calculated in accordance with IEEE Standard 80 in appendix AX.7.1.5.3 GPR (Ground Potential Rise) :Ground potential rise is the maximum electrical potential that a substation grounding grid may attain relative to a distant grounding point assumed to be at the potential of remote earth. This voltage, GPR, is equal to the maximum grid fault current times the grid resistance. (Grid resistance will be determined using the software WinIGS).7.1.6 Substation Fence GroundingThe grounding of the substation fence is critical because the fence is generally accessible to the public. The substation grounding design should be such that the touch potential on both sides of the fence is within the calculated tolerable limit of touch potential. The substation fence should be connected to the main ground grid by means of an outer grid conductor installed a minimum of 0.91 meter (3 feet) (approximately one arm’s length) outside the substation fence. Connections to the outer grid conductor should be made at all corner posts and at line post every 12.92 to 15.24 meters (40 to 50 feet). The gateposts should be securely bonded to the adjacent fence and the grid extended below the gate swing. It is recommended that all gates swing inward and be designed and installed to prevent an outward swing. If gates are installed with an outward swing, then the ground grid should extend a minimum of 0.91 meter (3 feet) past the maximum swing of the gate. The reasons to extend the ground grid to cover the swing of the gate are the same as the reason to install a ground conductor 0.91 meter (3 feet) outside the fence. The voltage above remote earth decreases rapidly as one leaves the substation grounding area. For example, if a person standing outside the substation grounding grid touches a fence or outward-swung gate under substation fault conditions, the resulting potential difference could be large enough to pose a serious danger.1.2.14Control and Power Cable1.2.15Control and Relay Panels1.2.16SCADA RTU1.2.17Revenue Metering1.3Outage Schedule1.4.1 Load and fault studies: Load and fault studies are done by our client Burns & McDonnell. Below is given a short definition of load and fault studies and their purposes. The Short Circuit Study provides the calculated information necessary to properly size the circuit breakers and fuses to successfully interrupt a short circuit, and as well as to determine the forces encountered in the substation due to these short circuit currents. This type of study tells what the maximum amount of fault current is available for particular type of fault(s). In addition, the Short Circuit Study will provide symmetrical and asymmetrical current values for the faults. A Load Study is the analysis of power availability and usage within a system. The study will determine the voltage regulation and maximum steady state current demands for the various pieces of equipment in the substation at both 138 and 69KV. x.1Coupling Capacitor Voltage TransformersSingle Phase CCVT Ratings:Primary voltage: 138/√3 kVSecondary voltage: 69/√3 kVRatio: 2500/4500:1Accuracy class:X1-X2-X3 Winding - 0.3 W, X, Y, Z, & ZZ BurdenY1-Y2-Y3 Winding - 0.3 W, X, Y, Z, & ZZ BurdenBasic Impulse Level (BIL): 550 kVTotal Capacitance: greater than 3000 pfProvisions:Porcelain bushing (ANSI 70 gray).Tank paint color will be ANSI-70 VTs will be supplied with NEMA standard 4-hole pads on HV bushing terminal.Carrier accessories required on all CCVTs. X Diagramsx.1 Control AC Schematic DiagramsTo be completed next semester.x.2 Control DC Schematic DiagramsTo be completed next semester.x.3 One Line DiagramAppendixx.4 Three Line DiagramTo be completed next semester.AppendicesEquationsWind Loads:Span or Support Spacing:Grounding:Grounding System Calculations: Step, Touch & reduction factor Calculations: Step & touch potentials were calculated using WinIGS :Permissible touch voltage = 1074.4V(Over Insulating Surface Layer) Permissible Step Voltage = 677.6V (Over Native Soil) -They can also be calculated by hand using the following equations:Etouch = IB ?RB + 1.5 Csρ?Estep = IB ?RB + 6 Csρ??Where: RB is the resistance of the human body in Ω, approximately=1000 Ω IB : is the rms magnitude of the current through the body in A, IB = 0.116ts for 50kg body weight. ρ: is the resistivity of the earth beneath the surface material in Ω·m (ρ= 320.1Ω·m) from soil data Cs : is the surface layer derating factor, determined using this equation: Where is the thickness of the surface layer (m) = 0.152 of crushed rock in my design. is the resistivity of the surface layer material (Ω.m) = 3000 Ω.m for crushed rock.Cs = 1- .09(1-320.13000)2*0.152+0.09 = 0.796Finally calculating the permissible touch & step: Etouch = IB ?RB + 1.5 Csρ???? 0.1160.25 (1000 + 1.5*0.796*3000) = 1062.97 VoltsEstep = IB ?RB + 6 Csρ???? 0.1160.25 (1000+ 6*1*321.14)=678.8332V, Cs = 1 Over Native SoilLightning and Shielding:138kVhe = 25'rc = 0.0702'Zs = 60*ln(2*he/rc)Zs = 60*ln(2*25/0.0702)Zs = 394.11ΩIs = 2.2*BIL/ZsΙs = 2.2*550/394.11Is = 3.07kAS = 26.25*k*Is^0.65S = 26.25*1.2*3.07kAS = 65.31'69kVhe = 15'rc = 0.0702'Zs = 60*ln(2*he/rc)Zs = 60*ln(2*15/0/0.0702)Zs = 363.46ΩIs = 2kA (<69kV)S = 26.15*k*Is^0.65S = 26.25*1.2*2S = 49.43'k is a coefficient to account for different strike lengths to a mast, shield wire, or ground plane.k = 1.2 for masts; 1.0 for shield wire or ground planeMomentary Current:Formulas given below are based on IEEE C37.04-1999, and IEEE C37.09-1999 Below is my calculation:Iasymetrical = Isymetrical * 1+2(%dc100)2%dc = 100 e-α , α = (XR2πf)@ 60 HZ , XR= 11.44417 ( given in scope) α = (XR2πf) = (11.444172π(60)) = 0.030357%dc = 100 e-0.030357= 97.0099Isymetrical = 20,000 Iasymetrical = 20,000 * 1+2(97.0099100)2 = 33953.997Busbar ExpansionCantilever Strength:Short Circuit Force:Bus HeightRigid Bus SpreadsheetIsokeraunic ChartLIGHTNING SHIELDING CALCULATIONS138kVhe = 25'rc = 0.0702'Zs = 60*ln(2*he/rc)Zs = 60*ln(2*25/0.0702)Zs = 394.11ΩIs = 2.2*BIL/ZsΙs = 2.2*550/394.11Is = 3.07kAS = 26.25*k*Is^0.65S = 26.25*1.2*3.07kAS = 65.31'69kVhe = 15'rc = 0.0702'Zs = 60*ln(2*he/rc)Zs = 60*ln(2*15/0/0.0702)Zs = 363.46ΩIs = 2kA (<69kV)S = 26.15*k*Is^0.65S = 26.25*1.2*2S = 49.43'k is a coefficient to account for different strike lengths to a mast, shield wire, or ground plane.k = 1.2 for masts; 1.0 for shield wire or ground planeCalculations (Momentary Current)Formulas given below are based on IEEE C37.04-1999, and IEEE C37.09-1999 Below is my calculation:Iasymetrical = Isymetrical * 1+2(%dc100)2%dc = 100 e-α , α = (XR2πf)@ 60 HZ , XR= 11.44417 ( given in scope) α = (XR2πf) = (11.444172π(60)) = 0.030357%dc = 100 e-0.030357= 97.0099Isymetrical = 20,000 Iasymetrical = 20,000 * 1+2(97.0099100)2 = 33953.997CommunicationsGrounding System Calculations: Step, Touch & reduction factor Calculations: Step & touch potentials were calculated using WinIGS :Permissible touch voltage = 1074.4V(Over Insulating Surface Layer) Permissible Step Voltage = 677.6V (Over Native Soil) -They can also be calculated by hand using the following equations:Etouch = IB ?RB + 1.5 Csρ?Estep = IB ?RB + 6 Csρ??Where: RB is the resistance of the human body in Ω, approximately=1000 Ω IB : is the rms magnitude of the current through the body in A, IB = 0.116ts for 50kg body weight. ρ: is the resistivity of the earth beneath the surface material in Ω·m (ρ= 320.1Ω·m) from soil data Cs : is the surface layer derating factor, determined using this equation: Where is the thickness of the surface layer (m) = 0.152 of crushed rock in my design. is the resistivity of the surface layer material (Ω.m) = 3000 Ω.m for crushed rock.Cs = 1- .09(1-320.13000)2*0.152+0.09 = 0.796Finally calculating the permissible touch & step: Etouch = IB ?RB + 1.5 Csρ???? 0.1160.25 (1000 + 1.5*0.796*3000) = 1062.97 VoltsEstep = IB ?RB + 6 Csρ???? 0.1160.25 (1000+ 6*1*321.14)=678.8332V, Cs = 1 Over Native Soil ................
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