Expert Details

Expert in Power Electronics and Renewable Energy Systems

Expert ID: 107831 Texas, USA

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Expert's expertise is in the area of power electronics and utility interface issues. He has designed and developed several low-cost static power conversion topologies for several applications. He is knowledgeable in a wide range of power conversion issues including pulse width modulation (PWM) techniques; suppression of specific unwanted harmonics; various types of DC-DC, DC-AC, AC-AC, and single-phase and three-phase power conversion systems; UPS and emergency standby system design, and battery charging converters in electric/hybrid electric propulsion systems. Expert has consulted with industry in the design of "clean" power converters, which draw sinusoidal input currents at unity power factors to meet strict harmonic current/voltage distortion limits specified in IEC 1000-3, IEC 61000-3-4, IEEE 519-1992, and German VDE standards.

Expert is very familiar with the characteristics of modern power semiconductor devices and their usage in high-frequency link converters, flyback power supplies, and resonant transition power conversion. He has expertise with the design of closed loop control circuitry for switching power converters. Expert has applied digital signal processing control (DSP) for UPS system output voltage regulation feeding varying nonlinear loads. He has consulted with industries in the area of renewable energy power conversion systems such as wind, fuel cells, and solar energy systems.

Expert is experienced with electronic ballast design for fluorescent and high intensity discharge (HID) lamps. He has consulted with clients in reducing the cost and improving the power factor and line current distortion without sacrificing high-frequency lamp operation. He is familiar with conventional and electronic ballast technology for HID lamps. Expert has designed and developed switched DC and high-frequency electronic ballasts for HID lamps. He has developed specific frequency modulation techniques to stabilize high-frequency operation of metal halide lamps and also formulated mathematical models for acoustic resonance phenomenon. With Intota, formerly Teltech, Expert participated as the lead technical expert to write a research dossier on electronic ballasts for HID lamps.

Expert has the necessary experience in specifying variable speed AC/DC motor control systems in energy saving applications. He has consulted with inverter/motor manufacturers to study and recommend solutions to several application related problems associated with modern PWM motor controls. More specifically, Expert has evaluated the effects of using long motor leads (cables) between the PWM-inverter and the motor. He has reviewed and evaluated various electronic speed control methods for induction motors, DC motors, brushless DC motors, switched reluctance motors, and permanent magnet synchronous motor drive systems. He has experience in selecting appropriate technology for Adjustable Speed Drive (ASD) Ride-through for voltage sags and short-term power interruptions. He has consulted with industries on the selection of adjustable speed drives and solving specific problems associated with the drilling industry, steel mills, pulp and paper mills, and others.

In work related to motor controls, Expert designed and developed filters to mitigate the effect of high PWM dv/dt, reduce overvoltages at the motor terminals, and turn insulation voltage stress within the motor windings. He has extensively evaluated the effects of fast turn-on IGBTs and high PWM dv/dt on motor bearing currents and the problem of neutral-shift in medium voltage drive systems.

Expert has consulted with numerous industries in evaluating harmonic distortion at the point of common coupling and has proposed solutions to reduce total demand distortion (TDD) in order to comply with IEEE-519 limits. In the area of mitigating harmonics, Expert is knowledgeable of the selection and placement of passive harmonic filters (traps) in the electric distribution systems. His invention - active filters to reduce neutral current harmonics in low-voltage, three-phase electric distribution systems is now a commercial product. He is also familiar with modern static transfer switch design and applications to dual feed systems, battery energy storage, and SMES systems to improve power quality.

As the Director of the Power Electronics and Power Quality Laboratory at Texas A&M University, Expert is very familiar with utility power quality-related issues and their solutions. He has designed and evaluated numerous single phase and three phase power factor correction circuits for switching power supplies. His laboratory frequently tests industry equipment for compliance to the international standards and consults with the power supply industry to meet IEC 1000-3. Expert is well-versed with IEEE 519-1992 recommended practice for voltage/current harmonic limits.

Expert participated in several on-site technical reviews of new products for clients involved in designing new power conversion and motor drive technology.Expert is a recognized authority in the power electronics industry and a competent, credible addition to your power conversion legal team. As a technical power electronics expert, he can quickly assess case details and prioritize the key points. As an experienced executive, he can provide industry overview and recognize the business implications at hand.
Primary Services
He can assist your legal team in the following areas:
• Review documents to:
- Determine the soundness of your case
- Extract the key supporter for the case
- Recognize and neutralize potential weaknesses
- Analyze intellectual property issues
• Find additional significant documents and information to strengthen your case
• Sharpen your power conversion legal strategy
• Act as a power conversion expert witness
• Prepare declarations and expert reports
• Sit for depositions
• Suggest questions that you should ask - and give you the answers
• Train your staff in power electronics technology and terminology Areas of Expertise

Expert may consult nationally and internationally, and is also local to the following cities: Houston, Texas - Austin, Texas - Pasadena, Texas - Waco, Texas - Killeen, Texas - College Station, Texas - Baytown, Texas - Bryan, Texas - Sugar Land, Texas - Round Rock, Texas

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Year Degree Subject Institution
Year: 1988 Degree: Ph.D. Subject: Electrical Engineering Institution: Concordia University, Montreal
Year: 1982 Degree: M.S. Subject: Electrical Engineering Institution: IIT Kanpur, India
Year: 1980 Degree: B.S. Subject: Electrical Engineering Institution: Osmania University, India

Work History

Years Employer Title Department Responsibilities
Years: 1998 to Present Employer: Undisclosed Title: Professor Department: Responsibilities:
Years: 1994 to 1998 Employer: Texas A&M University Title: Associate Professor Department: Responsibilities:
Years: 1988 to 1994 Employer: Texas A&M University Title: Assistant Professor Department: Responsibilities:
Years: 1984 to 1987 Employer: Concordia University, Montreal Title: Graduate Research Assistant Department: Responsibilities:

Career Accomplishments

Associations / Societies
Expert is a member of the IEEE Industry Applications Society, the IEEE Power Electronics Society, and the IEEE Industrial Electronics Society.
Licenses / Certifications
He is a Professional Engineer in the state of Texas.
Professional Appointments
Expert is a member of IEEE IAS Executive Board. He is also the Chair of the Standing Committee on "Electronic Communications."
Awards / Recognition
He received the IEEE Fellow award for "contributions to solutions of utility interface problems in power electronic systems and harmonic mitigation." The IEEE directory describes the honor as "one of unusual professional distinction conferred only by the [IEEE] Board of Directors upon a person of extraordinary qualifications and experience." He was the recipient of the IEEE-IAS second and third best paper award in 1993, 1996, 1998 and 1999 respectively. He received the second best IEEE-IA transaction paper published in mid-year 1994 to mid-year 1995. He also received the IEEE-IAS Magazine Prize Article Award in 1996.
Publications and Patents Summary
Expert has three patents, several others pending, and over 50 IEEE Publications.

Additional Experience

Expert Witness Experience
Expert has conducted several patent reviews and has provided expert report preparation to several law firms in the area of power electronics and power conversion.
Training / Seminars
1. Tutorial Co-Presenter “Design considerations of photovoltaic power systems installed on curved surfaces” IEEE ECCE 2011 Conference, Phoenix, AZ, Sept 18, 2011; Lead presenter: Dr. Robert Balog
2. Tutorial on “Power Conditioning Systems for Fuel Cells”, March 7,8,9, 2007, Tubitak Mam, Energy Research Institute, Istanbul, Turkey
3. Tutorial on “Fuel Cell Power Conditioning”, Fuel Cell Seminar, 2005, November 2005, Palm Springs, CA
4. Tutorial on “Fuel Cell Power Conditioning”, Fuel Cell Seminar, 2004, November 2004, San Antonio, TX
5. Tutorial on “Fuel Cell Power Conditioning”, Fuel Cell Seminar 2003, November 2003, Miami Beach, FL
6. Advanced Fuel Cell Power Conditioning Systems, National Technology University, Sponsored by US Department of Energy, March 25th to March 27th, 2002, Course Link
7. Tutorial on “Power Electronics for Distributed Energy Systems: Fuel Cells and Microturbines”, CIEP’02 Seminar on October 20th 2002, Guadalajara, Mexico,
8. An Overview of Single Phase and Three Phase Power Factor Correction Methods for Switching Converters, IEEE Applied Power Electronics Conference, March 10th, 2002, with Oscar Garcia
9. Low Cost Approaches for Mitigation of Harmonics and Ensure Power Quality Compliance of Adjustable Speed Drive Systems, ICPE’01 Conference, Seoul, Korea, October 15th, 2001
10. Utility interface issues of Power Electronic Equipment, IEEE Industry Application Society Annual Conference, October, 1999, Tutorial topic presenter.
11. Design of three-phase rectifier system with Clean input power characteristics, IEEE Power Electronics Specialists Conference, June 1999, with Ira. J. Pitel
12. How to select and apply an adjustable speed ac drive, IEEE Applied Power Electronics Conference, March, 1999, with V.R. Stefanovic
13. Assessment of ride-through alternatives for adjustable speed drives, PCIM98 Conference, November 1998, with A. von Jouanne
14. Fundamentals of Brush-less motor control, Tutorial topic presenter at Motor College, Small Motors Manufacturing Association, April, 2000, 1999 & 1998, with Dal Ohm
15. “Motor Drive/Power System Interaction”, IEEE Industry Application Society Annual Conference, October, 1997, Tutorial topic presenter
16. “Adjustable speed ac motor drives: Application problems”, European Power Electronics Conference, September 6th, 1997, Trondheim, Norway, with F. Blaabjerg and J. Pederson
17. “Power Electronics Simulation with Pspice”, Presented to Baldor Motors & drives design engineers”, April 1997
18. “Power Quality considerations of power electronic systems and the application of Active Filters” Presented at the University of Concepcion, Concepcion, Chile, March 1997
19. “Electronic ballast’s for fluorescent and high intensity discharge lamps”, PCIM 1996 Conference.
20. “Utility interface issues of power electronic converters”, Tutorial topic presenter on - case studies of harmonics in low voltage three phase four wire electric distribution systems, IEEE Industry Application Society Annual Conference, 1995 and 1996.
21. “Application of adjustable speed ac motor drives - problems and some low cost solutions”, PCIM95 & PCIM 96 Conference and IEEE APEC 1996 Conference.
22. “Introduction to Power System Harmonics and Active Harmonic Filtering”, to IEEE Houston section IAS/PES members, April 20-21, 1994
23. “Power Electronics Simulation” - Tutorial, Presented at CIEP94 3rd International power electronics conference, Puebla, Mexico, August, 1994 and PCIM Conference, October, 1994.
24. “Simulation of high power electronic systems and motor drives”, Toshiba industrial division, Houston, TX, Oct. 1994 and Allen Bradley Industrial division, Milwaukee, WI, March 1995
25. “Simulation of Power Electronic Circuits with PSPICE”, AT&T Power Supply Group, Mesquite, TX, April 6,7 and November 29, 30 1994.
26. “Advanced Pulse width Modulation (PWM) Techniques”, IEEE APEC Conference Seminar, Dallas, TX, 1991.
Other Relevant Experience
He is the lead developer of the Power Electronics/Power Quality Laboratory and Fuel Cell Power Systems Laboratory at Texas A&M University. Expert is also actively involved in many projects with industries while at the same time engaged in teaching, research, and consulting. He consults in the area of power electronics, motor drives, fuel cells, power quality, and clean power utility interface issues.

Fields of Expertise

electric-power conversion, electric-power converter, power electronics, alternating-current to direct-current conversion, direct-current to alternating-current conversion, direct-current to alternating-current converter, resonant transition power conversion, switching power converter design, high-frequency electric power converter, high-frequency link converter, solar energy, solar energy system, wind energy, energy-efficient fluorescent ballast, fluorescent lamp ballast, compact fluorescent lamp, fluorescent lamp design, electronic fluorescent lamp ballast, high-intensity discharge lamp, motor controller, motor drive, motor drive design, variable-speed motor control, alternating-current variable-frequency motor, direct-current motor drive, variable-speed drive, energy-efficient variable-speed drive, overvoltage protection, overload protection, electrical overvoltage, active filter, active power filter, alternating-current power line harmonic, passive filter, power factor controller, electric power quality, power quality assurance, power-supply circuit, dc link converter, DC to DC conversion, DC-to-DC converter, energy-efficient lighting controller, energy-efficient lighting device, energy-efficient lighting system, fluorescent lamp technology, flyback power supply, flyback transformer, frequency modulation, high-voltage power converter design, high-voltage power supply circuit, power engineering, power factor, switched-mode power supply circuit, uninterruptible power system, report preparation, battery industry, high-pressure sodium lamp, alternating current motor controller, fluorescent lamp failure analysis, lighting design, solar power supply, direct-current relay, electric motor failure, variable-speed alternating-current motor drive, open-circuit voltage, Electric Power Research Institute, output power rating, linear power-supply circuit, starting box, power field-effect transistor, automatic train control system, aerospace battery, direct-current voltage, output power, electric power system, PSPICE software, fluorescent lighting tube, lighting system design, capacitor testing, solar energy application, solar technology, automobile battery, power supply safety, resonant transition power converter, electric power generation equipment, electric current measurement, space electronics science, incandescence, alternating current, direct current, intellectual property, pulse-width modulation, capacitor reliability, electronic-device-component life-prediction methodology, electronics reliability testing, power semiconductor device new product development, power metal-oxide semiconductor field effect transistor, lighting system technology, high-voltage engineering, direct-current motor application, power semiconductor device, alternating-current to alternating-current converter, power quality, power generation system, electronics engineering, electronic device design, alternating-current to direct-current converter, alternating-current to alternating-current conversion, fluorescent lighting system, constant-current source, electric power distribution, energy-efficient incandescent lamp, direct-power generator, energy conversion, high-frequency semiconductor, alternating-current to direct-current conversion, alternating-current motor, alternating-current frequency divider, amplitude-modulation radio frequency, electric power, alternating-current motor drive, quality high-power converter, high-voltage transformer, choke coil, capacitor filter, contact rectifier, electronic rectifying element, passive electronic element, dynamo electric rotary transformer, synchronous converter, heating, ventilating, and air-conditioning equipment, electronic device, lighting system, resistor, pulse transformer, propulsion, power inductor, operational amplifier, lighting device, incandescent lamp, fluorescent lamp, electronics testing, electrical safety, electric motor, electric filter, direct-current amplifier, derating, capacitor, analog circuit

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