Novel Pulse-width Modulation Strategy to Minimize the Switching Losses of Z-Source Inverters

Abstract

AbstractThis article proposes a novel pulse-width modulation strategy to minimize switching losses of the Z-source inverter. The Z-source inverter has different pulse-width modulation patterns unlike the conventional voltage source inverter. Shoot-through states have been inserted within the zero states of the traditional pulse-width modulation patterns of a voltage source inverter to boost DC input voltage. Thus, the Z-source inverter has six active states, two zero states, and additional shoot-through states differentiating the Z-source and conventional voltage source inverters. The currents flowing through the switches of the Z-source inverter are larger than those of the conventional voltage source inverter, because Z-network currents must flow through the switches during the shoot-through states. Therefore, shoot-through currents increase the total switching losses of the Z-source inverter. In this article, switching losses of the Z-source inverter with the existing pulse-width modulation strategy are analyzed in detail. Then, new modulation signals of the Z-source inverter are introduced to produce unique pulse-width modulation patterns that minimize the switching losses of the Z-source inverter. The switching losses of the Z-source inverter with both pulse-width modulation strategies are simulated and compared. In addition, an experimental system has been built and tested to verify the effectiveness of the proposed strategy.Keywords: Z-source Inverter (ZSI)switching lossespulse width modulation (PWM)shoot-through statesspace vector modulation (SVM)digital scalar PWM (DSPWM)hybrid PWMzero state intervalsmodified space vector modulation (MSVPWM)switching currents Additional informationNotes on contributorsSeonghwan KimSeonghwan Kim received the B.S, M.S., and Ph.D. degrees in electrical engineering from Korea University, Seoul, Korea in 1991, 1995, and 1998, respectively. He became an Assistant Professor in 1999, and he is currently a Full Professor in Department of Control and Robot Engineering, Mokpo National University, Jeonnam, Korea. He was a visiting scholar in the University of Michigan-Dearborn, USA from Feb. 2012 to Jan. 2014. His main research interests include the application of intelligent control to ac motor drives, power electronics, and renewable energy. Janghyun ParkJanghyun Park received the B.S, M.S., and Ph. D. degrees in electrical engineering from Korea University, Seoul, Korea, in 1995, 1997 and 2002, respectively. He is currently a professor in the department of Control and Robot Engineering, Mokpo National University, Jeonnam, Korea. His research interests include neuro control, fuzzy control, adaptive nonlinear control, robust control, and their implementations to the real plant.Kwangwoon LeeKwangwoon Lee (M'04) received the B.S., M.S., and Ph.D. degrees in electrical engineering from Korea University, Seoul, Korea, in 1993, 1995, and 1999, respectively. From 2000 to 2002, he was at the Samsung Advanced Institute of Technology, Younggin-si Gyunggi-do, Korea, where he was involved in developing micro electro-mechanical systems sensor applications. From 2002 to 2007, he was a Senior Research Engineer at the Samsung Living Appliance R&D Center, Samsung Electronics, Suwon, Korea, where he was engaged in the research on sensorless motor drive systems for refrigerators and air conditioners. He is currently an Assistant Professor at the Department of Electronic Engineering, Mokpo National Maritime University, Mokpo, Korea. He was a visiting scholar in the University of Michigan-Dearborn, USA in 2013. Dr. Lee was the recipient of the 2008 Second Prize Paper Award from the Electric Machines Committee of the IEEE Industry Applications Society. His research interests include power electronics and control, which includes ac machine drives, digital signal processing (DSP)-based control applications, and fault diagnosis of electrical machines.Taehyung KimTaehyung Kim received the Ph.D. degree from Texas A&M Uni