EE 413 – Introduction to Electrical Engineering Practice



EE 415 – Electrical Engineering Senior Project - Final Report

“Plasmatron” Plasma Exciter

Developed in Conjunction with

Advanced Energy Industries, Inc. – Voorhees, NJ

[pic]

Project by : Joseph Eugene Palaia, IV

May 13, 2002

Professor : Dr. James K. Beard

Advisor : Mohammed Feknous

New Jersey Institute of Technology - Mt Laurel, NJ

|This report contains data proprietary to Advanced Energy Industries, Inc. of Voorhees, NJ. It's use is restricted to |

|academic evaluation unless specifically approved in writing by a designated representative of Advanced Energy |

|Industries, Inc. |

Table of Contents

Page .

Definition of Project 3

1. Introduction 3

a. Description 3

b. Background 4

c. Applications 6

d. Advantages and Disadvantages 7

2. Objective 9

3. Design Specification 10

4. Project Goals 11

a. Size 11

b. Cost of Additional Development 11

c. Performance 12

d. Educational Value 12

B) Description of Author’s Contribution 13

5. Theory of Operation 14

6. Schematic Circuit Diagrams 16

7. Necessary Equipment 18

8. Design and Construction Effort 19

a. Transformer Analysis 21

b. Description of PC Board Design 23

9. Bill of Materials 30

10. Testing and Analysis 31

C) Results of the Project 33

11. Originally Proposed Project Schedule 33

12. Concessions to Time Limitations 34

13. Final Result 35

14. Directions on Generator Operation for Demonstration Purposes 36

D) References 40

a. Individuals/Qualifications 40

b. Published Sources 40

Appendices

1) Data Sheets

2) Additional Pictures

3) Articles

Cover Page – 200kHz Plasma, generated by early, hand-made prototype unit at

Advanced Energy, Voorhees, NJ. 11/30/2000

A) Definition of Project

1. Introduction

a. Description

The production of toxic and polluting chemicals due to the burning of fossil fuels by internal combustion engines is a matter of extreme environmental impact. With the continued growth of our society, the use of the internal combustion engine is becoming more and more prevalent as the number of vehicles in use continues to increase. In the US alone, 131,838,538 passenger cars were registered in 1998. Obviously, as the number of cars increases, so does the volume of toxic and polluting emissions. If we are to preserve our natural environment for our children and our children’s children, then we must find a way to curb this stream of pollutants.

An early step has been taken in the state of California, which has recently announced new state regulations which will greatly reduce the acceptable levels of vehicle pollution. Under California’s new LEV II regulations to be phased in from 2004 to 2010, diesel passenger cars and light trucks will be included in the same category as gasoline-powered cars. Also, in January of 2001, the US EPA announced the reduction of emission standards for 2007 and subsequent model year heavy-duty diesel engines. These represent a 90% reduction of nitrogen oxide emissions, 72% reduction of non-methane hydrocarbon emissions, and 90% reduction of particulate matter emissions compared with the 2004 model standards. As a result of these new regulations, most large diesel trucks will no longer be allowed to drive on California highways, and soon, on highways nationwide. This could have an obviously devastating effect on the national economy, and especially, on California’s due to the use there of about 525,000 heavy-duty diesel trucks and 680,000 diesel-fueled engines used in construction and agriculture.

To provide a solution to this problem, Massachusetts Institute of Technology in conjunction with Advanced Energy Industries, Inc. has been in the process of developing a plasma treatment device for use with these engines. This device will break down gasoline, diesel fuel, or other hydrocarbon fuels and create hydrogen-rich gas, a high quality fuel. This is then used in the engine resulting in a drastic reduction of polluting chemicals, perhaps as much as a 100X reduction. While an intern at Advanced Energy, the author has been responsible for providing prototype generators for the research being conducted at MIT. This has entailed the design, construction, and troubleshooting of the amplifier circuit and necessary matching circuitry. It is the intent to present the development of this generator as the author’s senior project.

b. Background

A plasma, as defined by the American Heritage Dictionary is, “highly ionized gas composed of ions, electrons, or neutral particles. It is a phase of matter distinct from solids, liquids, and normal gases.” By exposing complex molecules to this highly energized state, the necessary energy is provided to increase reaction rates and break down these molecules. This is the basic concept of the device currently in development by MIT and AE, a device called the, ‘Plasmatron’. Hydrocarbon fuel is injected into a chamber, though a plasma which is generated inside. The plasma provides the energy to break the bonds, releasing hydrogen. In it’s nominal operation, one fourth of the hydrocarbon fuel is routed through the Plasmatron and broken down. The hydrogen-rich fuel is combined with the remaining fuel and is provided to the engine. The result is a modification of the combustion reactions leading to the reduced production of pollutants.

In order to create this plasma, it is necessary to utilize the 12V or 24V DC system present in large diesel trucks and convert it to a much higher voltage. In the Plasmatron, this voltage is delivered across a circular spark-gap. There must be a sufficiently high voltage to breakdown the dielectric (air/fuel mixture) and provide an arc. By injecting this mixture between the two circular electrodes off-center, the fuel follows a cylindrical motion around the inside of the chamber. Ordinarily the arc would remain at the location of the smallest distance between the electrodes. This leads to erosion of the electrodes at these locations. The cylindrical motion of the mixture forces the spark to also follow this cylindrical motion as it delivers it’s energy, hence a cylindrical plasma is formed.

Generating the necessary voltage to break down this spark gap and matching the generator to the load is the project at hand. This has involved the creation of the necessary circuitry, rough bread-boarding of the circuit and initial testing, pc board design for integration into an early package, production of a fully operational prototype, and testing and improvement of said prototype. Some of this work had been completed prior to EE413/EE415, and several prototype units with hand-soldered circuitry have been sent to MIT for testing. What remained to be done at the beginning of EE415 was the design of a printed circuit board and it’s implementation in a more refined prototype package. This will be presented as the conclusion of the author’s senior project.

c. Applications

The Plasmatron holds the potential for use in a number of commercial applications. Initial development is aimed towards use of the device in large trucks and equipment since these are often considered to be heavy polluters. Eventually, as the device becomes more refined and compact, it will be introduced into the conventional automobile market.

The device can also be used to provide a hydrogen source for fuel cells. By running conventional fossil fuels through it, hydrogen, CO, and CO2 are produced. Fuel cells are intolerant of CO but have no problem with CO2. This limitation can be overcome by converting the CO to CO2 through use of a simple chemical reaction known as the, “water-shift reaction.” The CO2, and hydrogen is then fed into the fuel cell along with oxygen from the atmosphere. The result is CO2, water and electricity. In the case of fuel cell vehicles this could provide a just-in-time hydrogen source, allowing for the storage of energy in the relatively stable hydrocarbon molecules rather than through hydrogen stored in large and potentially dangerous tanks.

Finally, there is the possibility of using the Plasmatron in back-up power generators. Running the device initially off of a battery, hydrogen would be produced to begin the operation of the fuel cell. The fuel cell would produce enough energy to continue the operation of the Plasmatron, charge the battery and provide electrical power to a load, all while producing virtually zero emissions and storing the energy in relatively stable, conventional fossil fuels.

d. Advantages and Disadvantages

There are many possible advantages to this plasma based system. It’s implementation on large trucks, industrial equipment, and eventually on conventional automobiles will result in a drastic reduction of toxic and polluting emissions. Implementation on fuel cell vehicles will remove the necessity and burden of carrying a dangerous and bulky hydrogen tank on board. Implementation on backup generators will allow use of virtually any fossil fuel without the pollutants inherent in the use of internal combustion engines. The Plasmatron’s small size and relative simplicity will make it suitable for use onboard vehicles without the requirement of reducing vehicle range and performance. It will reduce the production of green house gases and conserve our nonrenewable energy resources. The result will be a cleaner environment for all mankind.

In order to fulfill this promise, the Plasmatron will need to be cheap, small, and light in weight. These are certainly prerequisites for application in the automobile industry. Initial development has been aimed for the large truck and heavy equipment industries since there, these restrictions are not as stringent. Once in production, the device will undoubtedly undergo a period of size and cost reduction. The fruit of this effort will be a device of suitable size, cost and weight for implementation under the hood of every car in America.

There remain a few disadvantages that will need to be overcome in order for the Plasmatron to become a viable pollution-reduction option. Foremost on this list is the generation of radio frequency interference and noise. The generation of a voltage of magnitude great enough to break down the spark gap within the device requires a switching circuit utilizing a square wave signal. Square wave signals retain high energy even in harmonics of increasing frequency. Sufficient shielding will have to be provided so that this noise does not harm electronics in or around the vehicle.

Another issue of some consequence would be the necessity to tailor the apparatus for each vehicle it would be installed in, since all vehicles are not built alike. Mounting hardware, power connections and fuel flow hardware would have to be designed and modified for each different kind of vehicle on which the device was to be implemented. This is simply a hurdle that will have to be dealt with at some point in time.

Finally, this is a device which will compete directly with other pollution reduction devices. There are many groups around the world exploring concepts to reduce the emissions from vehicles to levels in agreement with the new EPA regulations. It will be a challenge to maintain supremacy in this highly political and financial arena. To do so it will be necessary for the device to be inexpensive, easy to install and maintain, as well as the most effective.

2. Objective

The objective of this project was the construction of an LF (Low Frequency) Output, DC Input Generator / Amplifier. The frequency is slightly variable in the range from approximately 50kHz to 200kHz. The amplifier supplies as much as 1kW of electrical power to a proprietary spark-gap apparatus through a suitable matching network. The apparatus is being provided by MIT for use in the testing of this prototype generator. For experimentation and practicality purposes, the power delivered will be varied by manually controlling the level of DC input voltage.

The generator and matching network were built and tested both at Advanced Energy Industries, Inc. in Voorhees, NJ and at the NJIT, Mt. Laurel Technology Center facility utilizing equipment in the laboratories of both facilities. With the successful design, construction and testing of this prototype generator, all pertinent data has been included in this document and will be submitted for review by researchers at MIT, by the management of Advanced Energy, and by the faculty of NJIT. A final presentation of the working prototype will be made on May 13, 2002 at NJIT – Mt. Laurel. This will including a demonstration of the generator’s ability to create and maintain an atmospheric plasma. (Generation of hydrocarbon plasmas had been left to MIT and others who are crazy enough to do it).

3. Design Specifications

LF Power Supply Specifications for Prototype Plasmatron Generator

1. Input DC Voltage: 12V – 24V DC

2. Frequency: 200kHz

3. Power Level : as much as 1kW at 200kHz

4. DC/AC Conversion Efficiency: >60%, for car >80%

5. LF Output Impedance, Typical : 100 [pic] to 1000 [pic]

6. Output Voltage : 10kV to 20kV at specified frequency,

depending upon gap distance

7. Size: Generator Box (5” by 6” by 9”)

Transformer Box (5” by 6” by 4” deep)

8. Operating Temperature: Room temperature (for car 0 to 175

degrees F)

9. DC Power Input Connections: Two wire connections (for car, one wire +,

chassis ground).

10. Output HV Connections: HV wire connection with ground return

terminal. (for car, HV wire connection)

11. Cooling Conditions: Utilization of DC Fan(s) to cool generator.

12. Logic Supply Connections: Separate, external terminals (for car, logic

driven off same supply as power)

13. Finished Cost of Prototype: ................
................

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