The Distribution Static Compensator for Load Compensation

IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 27, NO. 3, MARCH 2012

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A DSTATCOM Topology With Reduced DC-Link Voltage Rating for Load Compensation With Nonstiff Source
Srinivas Bhaskar Karanki, Nagesh Geddada, Student Member, IEEE, Mahesh K. Mishra, Senior Member, IEEE, and B. Kalyan Kumar, Member, IEEE

Abstract—The distribution static compensator (DSTATCOM) is used for load compensation in power distribution network. In this paper, a new topology for DSTATCOM applications with nonstiff source is proposed. The proposed topology enables DSTATCOM to have a reduced dc-link voltage without compromising the compensation capability. It uses a series capacitor along with the interfacing inductor and a shunt filter capacitor. With the reduction in dc-link voltage, the average switching frequency of the insulated gate bipolar transistor switches of the DSTATCOM is also reduced. Consequently, the switching losses in the inverter are reduced. Detailed design aspects of the series and shunt capacitors are discussed in this paper. A simulation study of the proposed topology has been carried out using power systems computer-aided design simulator and the results are presented. Experimental studies are carried out to verify the proposed topology. Index Terms—Average switching frequency, dc-link voltage, distribution static compensator (DSTATCOM), hybrid topology, nonstiff source.

I. INTRODUCTION

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HE proliferation of power electronics devices, nonlinear loads, and unbalanced loads has degraded the power quality in the power distribution network [1]. To improve the quality of power, active power filters have been proposed [2]–[4]. The distribution static compensator (DSTATCOM) is a shunt active filter, which injects currents into the point of common coupling (PCC) (the common point where load, source, and DSTATCOM are connected) such that the harmonic filtering, power factor correction, and load balancing can be achieved. In practice, the load is remote from the

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His research interests include power quality, power electronic devices, and power electronics applications in power systems. KARANKI et al.: DSTATCOM TOPOLOGY WITH REDUCED DC-LINK VOLTAGE RATING FOR LOAD COMPENSATION WITH NONSTIFF SOURCE 1211 Nagesh Geddada (S’11) received the B.Tech. degree from J.N.T.U., Kakinada, India, in 2004, and the M.S. degree from the Indian Institute of technology Madras, Chennai, India, in 2009, where he is currently working toward the Ph.D. degree. His research interests include custom power devices and power electronics applications to power systems and control systems. B. Kalyan Kumar (M’07) received the B.Tech. degree from J.N.T.U., Hyderabad, India, and the Masters and Doctoral degrees from the Indian Institute of Technology, Kanpur, India, in 2003 and 2007, respectively. He is currently an Assistant Professor at the Indian Institute of Technology Madras, Chennai, India. His research interests include power quality, power system dynamics, and Flexible AC Transmission Systems. Mahesh K. Mishra (S’00–M’02–SM’10) received the B.Tech. degree from the College of Technology, Pantnagar, India, in 1991, the M.E. degree from the University of Roorkee, Roorkee, India, in 1993, and the Ph.D. degree in electrical engineering from the Indian Institute of Technology Kanpur, Kanpur, India, in 2001. He has 20 years of teaching and research experience. He was with the Electrical Engineering Department, Visvesvaraya National Institute of Technology, Nagpur, India, for approximately ten years. He is currently a Professor in the Department of Electrical Engineering, Indian Institute of Technology Madras, Chennai, India. His research interests include the areas of power distribution systems, power electronics, and control systems. Dr. Mahesh is Life Member of the Indian Society of Technical Education.