APEC 2002

March 10-14, 2002
The Adam's Mark Hotel
Dallas, Texas

Professional Education Seminars

SEMINARS AT A GLANCE

SESSION I
Sunday, March 10, 9:30 AM - 1:00 PM

SESSION II
Sunday, March 10, 2:30 PM - 6:00 PM

SESSION III
Monday, March 11, 8:30 AM - 12:00 Noon

SEMINAR DESCRIPTIONS

SESSION I
Sunday, March 10, 9:30 AM - 1:00 PM

S.1 Brushless DC And Switched-Reluctance Motor Drives

James M. Kokernak, Advanced Energy Conversion & David A. Torrey, Rensselaer Polytechnic Institute

San Antonio Ballroom A

This course is intended for those who work with either brushless dc or switched-reluctance motor drives and desire a better understanding of how they can be controlled. The presentation will be broken up into six parts that address the operation of these machines, and how they may be controlled. Part 1 provides an overview of the basic principles of how brushless dc motors operate. Part 2 discusses the converters used to operate brushless dc motors at variable speed. Switch specification, snubber circuits and clamps, thermal issues and costs are addressed. With a basic understanding of motor operation providing the motivation, Part 3 revisits the control of brushless dc motors, discussing issues such as system modeling, control loop design, and enhancements that can improve or extend performance of the drive. Part 4 provides an overview of the basic principles of how switched-reluctance motors operate. Part 5 discusses the converters used to operate switched-reluctance motors at variable speed. Again, switch specification, snubber circuits and clamps, thermal issues and costs are addressed. Part 6 revisits control of the switched-reluctance motors, also addressing modeling, control design and enhancements. Back To The Top

S.2 Practical Methods For Optimizing Power Transistor And Diode Selection

Eric Persson, International Rectifier

Houston Ballroom A

Selecting the proper size power transistor (FET or IGBT) and diode for any particular power electronics application should be a straightforward task-but often is not. The objective is to use the smallest silicon size that can handle the current, yet keep the die temperature to a safe limit. For DC applications, this is simple- but for the complex waveforms often found in power electronic circuits, many questions arise: When should you use average current ratings instead of peak or rms value: How do you determine the effective value of current for complex waveforms like those modulated by another low frequency waveform? How is transient thermal impedance used to determine the maximum die temperature for these complex waveforms?

Almost every power electronic application involves tradeoffs between worst-case values of current, voltage, and temperature against the need to reduce cost to the absolute minimum. How do you know if you are on the edge, or have plenty of margin in your design? Too close to the edge results in poor reliability, while too much margin means that costs are unnecessarily high. The objective of this course is to help the designer gain a better understanding of how to estimate device temperature applications. Conduction and switching loss mechanisms will be clearly explained. The difference between peak, average, and rms values, and when to use each, will be covered in detail.

This is an intermediate level course intended for power electronics designers and engineers who would like a practical course in sizing power devices. Back To The Top

S.3 Power Supply Design From The Trenches

Charles E. Mullett, Condor DC Power Supplies

Houston Ballroom B

This seminar takes the audience through a real power supply design, from start to finish, with special emphasis on the design of each magnetic component. A power-factor corrected, 100-watt multi-output forward converter is used as the example. Novices will gain much insight into the "total picture" of this exciting process, while the veteran designer will identify with the "war stories" and see some of the challenges in a new light. Non-designers will be fascinated to see just what their engineering colleagues are going through to come up with a new product design.

The focus of this seminar is twofold: First, it provides an overview of the entire power supply, including the operation of each functional block, from the input EMI filter through the rectifier, PFC stage, bulk storage capacitor, to the main power converter, output regulators, feedback control circuits and protection circuits. Second, it provides the design techniques for each of the magnetic components, including choice of core materials, wire, winding structure and test specifications, as well as selection criteria for the semiconductors.

While not meant as a substitute for a two- to four-day intensive course, it provides a valuable perspective of the design process and a solid foundation for further study. It shows the "big picture" and contains enough detail to be extremely helpful to new designers, field applications engineers in component companies, and sales engineers in the power electronics industry. A comprehensive bibliography is included. Back To The Top

S.4 Power Systems For Electronic Equipment

Robert V. White, Artesyn Technologies

Houston Ballroom C

This seminar gives an overview of designing power systems for electronic equipment. The seminar starts with a problem statement: Convert power from a given source into power that can be used by a given load. The first step is to review the basic types and characteristics of power sources and electronic equipment loads. The next discussion is of the possible power system architectures that can be used to move power from source to load: central, distributed and hybrid. Then the various building blocks, AC-DC power supplies and DC-DC converters are reviewed to understand how to choose the best one for a given application. Reliability and availability are most important in today's equipment and these get an extended review of the fundamentals. Important regulatory and agency standards are briefly reviewed. The discussion progresses to the fundamentals of power system protection and control methods. The emphasis is on understanding what is being protected, why it is being protected and choosing the best technique to achieve the needed performance. Distributed power systems are becoming common and the seminar dedicates a section to distributed power system fundamentals. The seminar concludes with a survey of batteries in power systems and some miscellaneous design topics. Back To The Top

S.5 EMI: Theory, Issues And Solutions

Michael J. Schutten, General Electric Corporate Research And Development

San Antonio Ballroom B

This seminar is intended for entry-level engineers wanting a fundamental understanding of electromagnetic interference (EMI) issues and experienced engineers desiring a thorough understanding of EMI concerns. The presentation introduces the concept of how energy couples between separate electronic circuits. The fundamentals of EMI are presented including theory, energy coupling mechanisms having the ability to corrupt or damage a circuit, troubleshooting approaches, and EMI fixes. The characteristics and electrical symptoms of the four methods of EMI energy transfer are presented: common impedance coupling, magnetic field coupling, electric field coupling, and radiation coupling. Understanding EMI theory allows simple noise equivalent circuit approximations and low cost, robust fixes at the circuit board or component level. PWB layout and IC decoupling procedures are derived from fundamental EMI concepts. Novel test methods are presented that decouple multiple simultaneous EMI problems allowing a systematic approach for improving and quantifying EMI susceptibility.Back To The Top

SESSION II
Sunday, March 10, 2:30 - 6:00 PM

S.6 Automotive Integrated Starter-Generator Systems

John M. Miller, Ford Corporation; Patrick McCleer, McCleer Power And Raymond B. Sepe, Electro Standards Laboratories

San Antonio Ballroom A

Automotive OEM's have announced plans to improve passenger vehicle fuel economy 25% or more by year 2005. Fuel economy improvement levels beyond current mandates are likely to be legislated during the next five years in North America. In Europe and Asia the mandates for reduced CO2 emissions are already coming into effect. This challenge of higher fuel economy standards is promoting optimized and sometimes novel vehicle power train architectures that combine the traditional heat engine with various forms of electric drives. Today hybridized power trains are commercially available and as 42V next generation automotive electrical power systems are deployed the consumer will see the availability of ISG systems. Vehicle power trains in which electric traction power levels are upwards of 50% of the heat engine peak power are, or will soon be, available as powersplit and through the road hybrids. The industry is now poised to introduce soft hybridization of power trains, enabled by the introduction of 42V PowerNet, and facilitated by advancements on full hybrids. In the case of such soft or mild hybrids the power levels are nominally 10 kW of peak power in a 42V system which is typically 5% to 10% of the heat engine peak power. This seminar will introduce the development of ISG for automotive applications, why a particular type of electric machine technology is selected and how the ISG is controlled for not only optimized performance but continued operation in the face of single and multiple faults. Back To The Top

S.7 An Overview Of Single-Phase and Three-Phase Power Factor Correction Methods For Switching Converters

Prasad Enjeti, Texas A&M University And Oscar Garcia, Universidad Politécnica de Madrid

Houston Ballroom A

The objective of this seminar is to present an overview of several single phase and three phase advance power factor correction (PFC) approaches for switching power converters. The course will begin with an introduction to national and international harmonic standards. Several active power factor correction approaches to realize sinusoidal input currents in single phase and three phase switching converters will be thoroughly reviewed. Application specific control ICs for PFC will be discussed. Digital control design for PFC with emerging low cost digital signal processors (DSP) will also be examined. Analysis, simulation and design of PFC methods will be dealt in per-unit to facilitate comparison. Throughout the course, numerous design examples with simulation and experimental results will be presented. Power electronic design engineers who deal with single phase and three phase power conversion for power supplies, switch mode converters, UPS, Battery chargers, rectifiers etc. You will find this course informative and the knowledge gained in this seminar can be immediately applied. Back To The Top

S.8 Analysis And Design Of Power Electronics Circuits Using PSpice

Thomas Salem, Elizabethtown College

Houston Ballroom B

This seminar will discuss using PSpice to analyze and design power electronic circuits. The presentation will address a variety of circuit topologies for both AC and DC converters. Emphasis will be placed upon using the circuit simulation as an engineering tool first to understand the topology, and then to develop and improve circuit design. Throughout the discussion, a variety of implementation tips and tricks for working with PSpice will be demonstrated. Details will be provided on recognizing and troubleshooting simulation difficulties and problems, using vendor supplied device models, understanding limitations on circuit simulations, and references for further information and assistance.

For the computer savvy entry-level engineer with a minimal background in power electronics, this course will provide a survey of power electronic converter simulation. For the intermediate-level engineer with a knowledgeable background in power electronics, this course will provide a detailed examination of developing PSpice circuit simulations. The overall focus of the course will be to promote self-learning and discovery of using PSpice as an engineering analysis and design tool. Back To The Top

S.9 Power Packaging Techniques For Low And High Voltage Systems

Douglas C. Hopkins, State University Of New York At Buffalo

Houston Ballroom C

This seminar provides the power electronics designer with an in-depth description of leading and next-generation power packaging techniques used in supplies and drives. Emphasis is placed on transitioning FR-4 systems to other packaging approaches to improve performance and reduce cost. The designer will gain familiarity with nomenclature, electrical and material characteristics, and guidelines for use of several packaging processes. In particular, the designer will gain an understanding of packaging characteristics that limit current and voltage, with emphasis on higher voltage systems (>1200V). Included will be a review of the latest in integrated thermal augmentations. A case study of a commercial power module will demonstrate an electrical/physical circuit design and be used to identify the critical packaging issues. This is an essential course for the designer who must look at other packaging design approaches to further shrink their electronics. Back To The Top

S.10 Overview Of HALT And HASS: Methods That Work

Kirk A. Gray, AcceleRel Engineering

San Antonio Ballroom B

Over the last decade, Accelerated Stress Testing (AST) has been embraced by an ever widening array of worldwide electronics design and manufacturing companies seeking to reconcile the need for the highest quality product with the necessary push for early time to market.

This AST Seminar is designed as an overview of these methods for product development, reliability, quality, and design validation engineers that want the basics on how to apply AST methods (also known as Highly Accelerated Life Test, or HALT, and Highly accelerated Stress Screens, or HASS). Those that attend will learn the reasons why leading companies are using the new orientation of testing to limits. Information will be presented on why basing screening on the capabilities of the material and physics of failure is so cost effective and time efficient. Attendees will learn in general the steps on how to implement an AST development and manufacturing screening process at their own facilities. The seminar will also present a case history of how a power supply manufacturer reduced warranty returns 5% to 0.5% at the same time they reduced testing time from 4 days to 1 hour. Back To The Top

SESSION III
Monday, March 11, 8:30 AM - 12:00 Noon

S.11 Sensorless Control Of Adjustable Speed Motor Drives: State Of The Art And Recent Advances

H. A. Toliyat, Texas A&M University And B. Fahimi, Electro Standards Laboratories

San Antonio Ballroom A

Detection of rotor position forms an integral part of control in adjustable speed motor drives. In fact, proper synchronization of the excitation with respect to spatial distribution of magnetic field is an essential step in optimal control of motor drives. Since rotor position portraits a one to one correspondence with magnetic status of the machine, it has been traditionally used for control purposes. External position sensors, such as optical encoders, Hall effect sensors, etc. are traditionally used for detection of rotor position. These sensors, however, contribute to unreliability, additional cost and size in most cases. This, in turn, has motivated substantial research on development of position sensorless control techniques all around the globe.

The main idea behind all these techniques stems from the fact that mechanical time constants of the motor drive systems are significantly larger than their electrical time constants. Given the impressive speed of computation in the state-of-the-art controllers, one can use the existing separation between system time constants to extract embedded position information from electromagnetic quantities of the machine. In fact, one might directly process the magnetic data to monitor the spatial distribution of the magnetic field thereby eliminating the need for position information in control.

The proposed seminar is intended to offer a systematic review of the position sensorless techniques in induction, BLDC and SRM motor drives. This will cover an entire range of topics related to these emerging technologies such as resolution versus speed range, four-quadrant operation, hardware intensive versus software intensive methods, etc. While presenting fundamentals of classified sensorless methods, we will also provide design examples to clarify important engineering issues. This will provide practicing engineers and graduate students with an insightful description of sensorless techniques. Back To The Top

S.12 Solar And Alternative Energy - The Engineering Issues

Dean Patterson, University Of South Carolina

Houston Ballroom A

The subject of "alternative" or "renewable" energy is one that typically evokes emotive and political responses, which often have higher visibility than the engineering issues. This tutorial is a very broad introductory overview of the field. It aims to provide you with the information, in terms of facts, figures, analytical tools, design procedures and costings to make engineering judgements about the viability of alternative energy sources for given situations, and to highlight the range of applications where they should be seriously considered.

The tutorial begins with an overview of the two-sided issue of energy provision and use, and then concentrates on the use firstly solar energy via photovoltaics, and secondly wind energy. The state of the art of technology for both of these will be examined in some detail.

The tutorial will include a survey of storage technologies. This will lead to the presentation of procedures for stand alone system design. The complementary issue of efficiency of energy use will also be addressed. Back To The Top

S.13 Soft-Switching In DC-DC Converters: Principles, Practical Topologies, Simulations And Design Techniques

Raja Ayyanar, University Of Arizona; Ned Mohan, University Of Minnesota And Eric Persson, International Rectifier

Houston Ballroom B

Soft-switching in dc-dc converters can result in improved energy efficiency, power density, reliability and lower EMI. The main objectives of this tutorial are as follows. To explain the basic principles of soft-switching, both zero-current switching (ZCS) and zero-voltage switching (ZCS). Brief survey of important topologies classified as resonant transition, quasi-resonant and resonant load topologies. Detailed discussion including the principles of operation, simulations and design techniques for a few popular topologies like the phase-shift controlled full-bridge converter, active reset ZVT forward converter etc. The effectiveness of the proposed design procedures will be clearly demonstrated using PSPICE simulations. The trade-offs involved in the design in terms of increased conduction losses, need for extra components and the additional complexity etc. will be discussed.

Discussion on the latest developments like the family of full-load-range hybrid full-bridge converters, soft-switching in power factor correction circuits, analysis of failure mode in phase-shifted full bridge converters due to poor reverse recovery characteristic of the body diode.

This tutorial is designed to benefit both entry level as well as experienced power supply designers, designers of switch mode converters, power factor correction circuits, technical managers, application engineers and professors teaching Power Electronics. Back To The Top

S.14 Puzzles And Answers In The Thermal Management Of Board-Mounted Power Modules

Frank Liang, Tyco Electronics Power Systems

Houston Ballroom C

The objective of this seminar is to clarify the misconceptions and identify the common mistakes in the thermal management of power modules through theoretical analysis, experiments and computer-based CFD simulations. Following a practical review of the fundamentals of heat transfer and fluid dynamics in a manner geared towards practicing power electronics professionals, the issues involved in thermal characterization testing of power modules are first discussed, followed by the "tricks" in power derating. Next covered are heat-sinking problems and other system and application issues, along with the common mistakes in thermal (CFD) modeling.

This seminar is designed as an intermediate-level broad tutorial, and is intended for general audience with common interest in thermal issues. Back To The Top

S.15 Understanding And Controlling Common-Mode Emissions In High-Power Electronics

Henry W. Ott, Henry Ott Consultants

San Antonio Ballroom B

Most people try to fix their common-mode emission problem without first understanding the basic cause of the problem. This at best leads to a trial and error approach to the solution. Therefore, this seminar starts out with a discussion of what causes common-mode emission problems and how common-mode currents are generated. This requires an understanding of what I like to call "the invisible schematic," as well as some basic principles of EMC. Once the source of the problem is understood, the control techniques become fairly straightforward and obvious. They are not "black magic."

A discussion of the applicable FCC and European Union EMC regulations, and the difference between them, is also included. Knowledge of these regulations is important since they determine the allowable magnitude of the common-mode emission -- and hence the degree of mitigation required. This seminar then goes on to describe basic control techniques, which include filtering, grounding, and shielding. This is followed by examples of these techniques applied to a switching power supply, and a high power IGBT motor drive circuit. The presentation concludes with a discussion of some simple techniques for measuring the common-mode emission-- since only by measuring the emissions, can you determine the effectiveness of your solution. This is an in-depth presentation on the subject of common-mode emissions and is intended for an intermediate level audience. Back To The Top