Power Electronics Graduate Certificate

This course introduces the basic concepts of switched-mode converter circuits for controlling and converting electrical power with high efficiency. Principles of converter circuit analysis are introduced, and are developed for finding the steady state voltages, current, and efficiency of power converters. Assignments include simulation of a DC-DC converter, analysis of an inverting DC-DC converter, and modeling and efficiency analysis of an electric vehicle system and of a USB power regulator.

After completing this course, you will:

• Understand what a switched-mode converter is and its basic operating principles
• Be able to solve for the steady-state voltages and currents of step-down, step-up, inverting, and other power converters
• Know how to derive an averaged equivalent circuit model and solve for the converter efficiency

A basic understanding of electrical circuit analysis is an assumed prerequisite for this course.

This course introduces more advanced concepts of switched-mode converter circuits. Realization of the power semiconductors in inverters, or in converters having bidirectional power flow, is explained. Power diodes, power MOSFETs, and IGBTs are explained, along with the origins of their switching times. Equivalent circuit models are refined to include the effects of switching loss. The discontinuous conduction mode is described and analyzed. A number of well-known converter circuit topologies are explored, including those with transformer isolation.

The homework assignments include designing a boost converter and an H-bridge inverter used in a grid-interfaced solar inverter system, as well as transformer-isolated forward and flyback converters.

After completing this course, you will:

• Understand how to implement the power semiconductor devices in a switching converter
• Understand the origins of the discontinuous conduction mode and be able to solve converters operating in DCM
• Understand the basic DC-DC converter and DC-AC inverter circuits
• Understand how to implement transformer isolation in a DC-DC converter, including the popular forward and flyback converter topologies.

Completion of the first course ECEA 5700 Introduction to Power Electronics is a prerequisite for this course.

In this course, students learn how to design a feedback system to control a switching converter. The equivalent circuit models derived in the previous courses are extended to model small-signal AC variations. These models are then solved, to find the important transfer functions of the converter and its regulator system. Finally, the feedback loop is modeled, analyzed, and designed to meet requirements such as output regulation, bandwidth and transient response, and rejection of disturbances.

Upon completion of this course, you will be able to design and analyze the feedback systems of switching regulators.

Completion of courses 1 (ECEA 5700 Introduction to Power Electronics) and 2 (ECEA 5701 Converter Circuits) are prerequisites for this course.

This course covers the analysis and design of magnetic components, including inductors and transformers, used in power electronic converters. The course starts with an introduction to physical principles behind inductors and transformers, including the concepts of inductance, core material saturation, air gap and energy storage in inductors, reluctance and magnetic circuit modeling, transformer equivalent circuits, and magnetizing and leakage inductance. Multi-winding transformer models are also developed, including inductance matrix representation, for series and parallel structures. Modeling of losses in magnetic components covers core and winding losses, including skin and proximity effects. Finally, a complete procedure is developed for design optimization of inductors in switched-mode power converters.

After completing this course, you will:

• Understand the fundamentals of magnetic components, including inductors and transformers
• Be able to analyze and model losses in magnetic components, and understand design trade-offs
• Know how to design and optimize inductors and transformers for switched-mode power converters

Completion of courses 1 (ECEA 5700 Introduction to Power Electronics) and 2 (ECEA 5701 Converter Circuits) are prerequisites for this course.

This is the first course in the Modeling and Control of Power Electronics Specialization. The course is focused on practical design-oriented modeling and control of pulse-width modulated switched mode power converters using analytical and simulation tools in time and frequency domains. A design-oriented analysis technique known as the Middlebrook’s Feedback Theorem is introduced and applied to analysis and design of voltage regulators and other feedback circuits.

Furthermore, it is shown how circuit averaging and averaged-switch modeling techniques lead to converter-averaged models suitable for hand analysis, computer-aided analysis, and simulations of converters. After completion of this course, students will be able to practice design of high-performance control loops around switched-mode power converters using analytical and simulation techniques.

This course is focused on two techniques of design-oriented analysis known as Middlebrook's Extra-Element Theorem (EET), and N-Extra-Element Theorem (NEET). It is shown how EET simplifies circuit analysis and design, allowing the designer to gain insights into effects of circuit elements initially neglected, and to formulate design approaches. NEET allows the designer to easily derive complex transfer functions in circuits such as converter filters and averaged circuit models.

Application examples related to switched-mode power converters are used to illustrate the use of EET and NEET in practice. Completion of this course will enable the student to practice powerful techniques of design-oriented analysis. Assignments include section quizzes, open-ended design problems, and a final exam.

Prerequisite: completion of Course #1 in the Advanced Modeling and Control course sequence.

The course is a prerequisite for Courses #3-5 in the Advanced Modeling and Control sequence.

To meet electromagnetic interference (EMI) requirements and to mitigate effects of switching noise, switching power converters often require input filters. Using Extra-Element Theorem, it is shown how addition of an input filter may compromise system stability, and impedance criteria are formulated to mitigate the system stability issues. Input filter design techniques are developed for single-stage and multi-stage filters to simultaneously meet attenuation requirements, properly damp filter stages and meet impedance criteria, and minimize the size of passive components. The techniques are illustrated in practical design examples. Upon completion of this course, students will be able to design converter input filters. Assignments include section quizzes, open-ended design problems, and a final exam.

Prerequisites: completion of Courses #1 and #2 in the Advanced Modeling and Control course sequence.

Control loops around switch-mode power converters are often based on current-mode control techniques.

This course is focused on analysis, modeling, and design of current programmed mode or peak current mode (PCM) control, as well as average current mode (ACM) control. Effects of sampling and the need for compensation ramp are introduced.

Averaged dynamic models and transfer functions of PCM controlled converters are developed, including a simple model, as well as a more accurate model. Completion of the course will enable the student to design practical high performance control loops using PCM and ACM control techniques in DC-DC, AC-DC and DC-AC applications. Assignments include section quizzes, open-ended design problems, and a final exam.

Prerequisites: completion of Courses #1 and #2 in the Advanced Modeling and Control course sequence.

This course covers digital control of switched-mode power converters. Digital control loops include analog-to-digital converters, discrete-time compensators, and digital pulse-width modulators. An introduction to discrete-time systems and discrete-time transfer functions is provided, based on prerequisite background in continuous-time analog control techniques, and mapping techniques.

Effects of delays and quantization effects are explained. A review of implementation techniques for digital controllers is given. Upon completion of this course, the student will be able to design practical digital control loops around switched-mode power converters. Assignments include section quizzes, open-ended design problems, and a final exam.

Prerequisites: completion of Courses #1 and #2 in the Advanced Modeling and Control.

A design project that applies the material of courses ECEA 5700, 5701, 5702, 5703, and 5705, to design and verify a bidirectional DC-DC converter and its controller, to interface a lithium-polymer battery to a USB-C device. Three milestones demonstrate: design and steady-state operation of converter power stage, averaged modeling and design of converter controller, and closed-loop transient response and regulation.

• Introduction and Power Stage Design
• Power Stage Design and Documentation. Milestone 1 submission.
• Preliminary Controller Design
• Preliminary Controller Design and Documentation. Milestone 2 submission.
• Complete Design
• Complete Design and Documentation. Milestone 3 submission.