Abstract
A pulse width modulation (PWM)-based control method for a three-level, four-wire neutral point clamped (NPC) inverter employed in a hybrid active power filter (HAPF) is proposed in this paper. The control method is based on switching function coefficients (SFCs) for harmonic compensation. An interior loop is also proposed for control and balancing of the DC-link voltages. In the proposed control system, one carrier signal is employed in the PWM unit in order to simplify its hardware as compared with traditional PWMs. Based on Fourier decomposition technique, mathematical analysis of the proposed control method is also presented. To decrease the NPC inverter rated power, passive power filters (PPFs) are designed to eliminate fifth and seventh order harmonic currents and to compensate source reactive currents. The proposed control system is implemented by a digital signal processing (DSP) in a laboratory prototype. The experimental results confirmed the validity of the proposed control method in compensation of harmonic currents under non-linear conditions
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Notes on contributors
Mehdi Asadi
Mehdi Asadi was awarded B.Sc., M.Sc., and Ph.D. degrees in electrical engineering from Iran University of Science and Technology (IUST), Tehran, Iran in 2002, 2004, and 2013, respectively. He is currently working with Arak University of Technology. His research interests are in power electronic, power quality, and electrical machine drives.
Alireza Jalilian
Alireza Jalilian was awarded a B.Sc. degree in electrical engineering from Iran in 1989, and M.Sc. and Ph.D. degrees from Australia in 1992 and 1997, respectively. Since 1998, he has been with the Department of Electrical Engineering, Centre of Excellence for Power System Automation and Operation, Iran University of Science and Technology (IUST), Tehran, Iran. Dr. Jalilian is currently an assistant professor and head of the power group at IUST. His research interests include power quality causes, effects, and mitigation methods.