## Power Electronics and Motor-Drive Textbook

The book is designed for senior undergraduate students in electrical engineering and the first year of graduate students who would like to know more about the applications of power electronics in motor-drives, wind, and solar energy systems. This book can be adopted as a textbook for (i) energy conversion, (ii) power electronics, and (iii) advanced power electronics courses. I have assumed that students taking the first two courses will know electric circuit analysis. Chapter 1, parts of Chapter 2, Chapter 3, and Chapter 4 can be used to teach the energy conversion course for undergraduate students. Chapter 1, parts of Chapter 2, Chapter 5, Chapter 7, and Chapter 8 can be used to teach the power electronics course for undergraduate students. The book can also be used to teach an advanced power electronics course for graduate students using Chapter 6, Chapter 9, Chapter 10, Chapter 11, and Chapter 12.

Semiconductor materials and solid-state switches are the backbones of power electronics. In Chapter 1, students can get familiar with some semiconductor materials and solid-state switching devices. They also learn about the characteristics of solar panels and wind turbines as intermittent energy resources and the need for solid-state-based power converters. In this chapter, a brief description of motor drive technology is also presented as the basis of electromechanical devices such as robots and powertrains in full-electric and hybrid electric vehicles. This chapter’s materials are carried on 25 figures, 25 mathematical expressions, and 7 examples, along with 15 exercise problems.

In Chapter 2, students learn the difference between linear, nonlinear, and switching circuits. The phasor and Laplace transformations are also reviewed through examples for solving linear circuits. The principles of inductor Volt-Sec-balance and capacitor Amp-Sec-balance are derived for switching circuits, and switching loss calculations are presented. In this chapter, students also learn how three-phase systems can be converted from the abc reference frame into the space vector, or the direct-quadrature-zero (dq0) reference frame. This chapter’s materials are carried on 28 figures, 159 mathematical expressions, and 23 examples, along with 16 exercise problems.

Magnetic circuits are the basis for the analysis of inductors, electric machines, and electromechanical actuators. In Chapter 3, students learn how to solve magnetic circuits and calculate the magnetic field energy. In particular, they learn about nonideality effects and loss calculations in magnetic cores. In this chapter, they also learn how the core nonideality is modeled in the equivalent electric circuits of inductors and transformers. This chapter’s materials are carried on 27 figures, 173 mathematical expressions, and 25 examples, along with 52 exercise problems.

Electric machines play an essential role in wind turbines, robotics, as well as hybrid and electric vehicles. Chapter 4 represents how electromagnetic force and torque can be derived from magnetic field calculations. Students also learn the steady-state circuit models and analysis of asynchronous (induction) and synchronous machines. This chapter’s materials are carried on 31 figures, 131 mathematical expressions, and 16 examples, along with 31 exercise problems.

DC-DC converters are used in DC power supplies, battery energy storage, and solar energy systems. In Chapter 5, students learn how to analyze DC-DC converters in two different steady-state operations, namely continuous and discontinuous conduction modes. This chapter covers main DC-DC converter topologies, buck, boost, buck-boost, isolated buck-boost (Flyback), and bidirectional half and full-bridge DC-DC converters, while the principles learned in this chapter can be extended for the analysis of other switching circuits. This chapter’s materials are carried on 34 figures, 134 mathematical expressions, and 16 examples, along with 33 exercise problems.

Chapter 6 is devoted to the dynamic behaviors of buck, boost, and buck-boost converters. In this chapter, students learn how the averaging technique is often used to simplify the model while capturing dynamic behavior. They also learn how to derive the converter transfer functions for designing the control schemes using the root locus technique. This chapter’s materials are carried on 20 figures, 73 mathematical expressions, and 7 examples, along with 14 exercise problems.

Chapter 7 deals with DC-AC converters (inverters) and their switching techniques to form an adjustable AC waveform from a DC source. The focus of this chapter is on single-phase and three-phase two-level voltage source inverters. In this chapter, students learn how to implement different pulse-width modulation (PWM) techniques for two-level inverters. They also learn the switching techniques for cascaded h-bridge and the diode-clamped multi-level inverters. This chapter’s materials are carried on 51 figures, 104 mathematical expressions, and 23 examples, along with 39 exercise problems.

In Chapter 8, students learn about the differences between passive and active AC-DC converters (rectifiers) for single-phase and three-phase systems. They learn how active rectifiers can regulate the output DC voltage, minimize the total harmonic distortion (THD), and provide unity power factor by making the AC-side current in phase with the voltage. This chapter’s materials are carried on 29 figures, 64 mathematical expressions, and 10 examples, along with 20 exercise problems.

Inverters are the last stage of wind and solar energy conversion systems. In Chapter 9, students learn about basic control schemes for grid-interactive inverters. They learn how inverters can be programmed to operate in grid-connected and islanded modes of operation and to provide ancillary services under abnormal conditions. This chapter’s materials are carried on 37 figures, 66 mathematical expressions, and 12 examples, along with 22 exercise problems.

The steady-state analysis of AC machines was covered in Chapter 4. In Chapter 10, students learn the dynamic models of AC machines in the dq0 reference frame. In particular, they first learn how to model the squirrel-cage and wound rotor induction motors and then learn how to model doubly-fed induction generators (DFIGs). They also learn dynamic models of the surface-mounted permanent magnet (SPM) and the interior surface permanent magnet (IPM) motors. This chapter’s materials are carried on 21 figures, 97 mathematical expressions, and 6 examples, along with 10 exercise problems.

Motor-drives are an essential part of many electromechanical systems such as electric vehicles and robots. In Chapter 11, students learn how inverters are controlled to develop adjustable voltage and current sources. Students learn how to build the scalar speed controller for squirrel-cage induction motors and vector control schemes for both squirrel-cage induction and PM motors. This chapter’s materials are carried on 12 figures, 44 mathematical expressions, and 3 examples, along with 6 exercise problems.

In Chapter 12, students learn why fast switching leads to electrostatic and magnetic couplings due to stray capacitances and inductances. They also learn how fast switching inverters generate high-frequency voltages, leakage currents, and traveling waves in motor-drives. This chapter’s materials are carried on 12 figures, 40 mathematical expressions, and 2 examples, along with 8 exercise problems.

## Teaching

### Spring Semester

ECE 530 - Control systems Design

Course Objective: To provide the students with an understanding of, and proficiency in the modeling and analysis of, continuous-time systems. The students will learn how to apply model the continuous-time systems, learn how to analyze the continuous-time systems, and learn how to design time-domain and frequency-domain controller systems to meet specified needs. A final project is designed to apply the control knowledge gained for a real-world problem using MATLAB/Simulink.

Prerequisites: Math 340 and ECE 512 Or Graduate Student.

ECE 824 - Advanced Power Electronics

Objective: To introduce students to the dynamics, switching patterns, and control of power electronic converters.

Prerequisites: ECE 624 - Power Electronics (electric circuit analysis, differential equations, feedback control systems).

ECE 581 - Energy Conversion

Course Objective: To introduce students to the principles of energy conversion including inductor design, transformers, torque and force in electromagnetic circuits and actuators, and fundamentals of electric machines (motors and generators).

Prerequisites: ECE 410 - Circuit Theory I (RL circuit analysis in time and phasor domains, power and energy calculations, three-phase circuits, Thevenin’s theorem, integral and partial derivative, Ampere’s and Faraday’s laws).

ECE 881 - Power Electronics for Renewable Energy Systems

Course Objective: To explore the electrical characteristics of PV energy sources, the requirements for grid-connection, and the system-level power electronic circuits and controls needed to perform the interconnection. IEEE, NEC, UL and other regulatory standards that govern PV systems will also be studied.

Prerequisites: ECE 511 - Electrical Circuits II, ECE 624 - Power Electronics

ECE 684 - Power Laboratory

Objective: To be familiar with laboratory equipment, learn characterization of machines and design of induction machines, test a PWM-based DC-DC buck converter and a single-phase inverter, and analyze grid fault and stability as well as microgrid operation using PSCAD software.

Prerequisites: ECE 581 - Energy Conversion, ECE 624 - Power Electronics, ECE685 - Power Systems Design

ECE 890 - System Identification and Adaptive Control

Course Objective: System identification methods are used to mathematically model a system via measured data which may be inadequate or uncertain. Adaptive control schemes provide an adequate control on the system with an uncertain model. This course provides an overview of system identification techniques and adaptive control schemes for time-varying systems. After taking this course, students should be able to use some system identification methods to design adaptive control schemes.

Prerequisites: ECE 530 - Control Systems Design

### Fall Semester

ECE 530 - Control systems Design

Course Objective: To provide the students with an understanding of, and proficiency in the modeling and analysis of, continuous-time systems. The students will learn how to apply model the continuous-time systems, learn how to analyze the continuous-time systems, and learn how to design time-domain and frequency-domain controller systems to meet specified needs. A final project is designed to apply the control knowledge gained for a real-world problem using MATLAB/Simulink.

Prerequisites: Math 340 and ECE 512 Or Graduate Student.

ECE 830 - Advanced System Theory

Course Objective: To learn state space description and analysis of continuous time dynamic systems and control solutions. Both linear and nonlinear systems are considered.

Prerequisites: ECE 530 - Control System Design or ME 640 - Control of Mechanical Systems II

ECE 624 - Power Electronics

Course Objective: To learn the fundamentals of power electronics, DC-to-DC converters operation (buck, boost, buck-boost), DC-to-AC converters (single-phase and three-phase PWM inverters), and AC-to-DC converters (single-phase and three-phase rectifiers).

Prerequisites: ECE 511 - Electrical Circuits II