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A Two Stage Power Converter Topology for High Voltage DC Power Supplies Under Pulsed Loads

2006; Taylor & Francis; Volume: 16; Issue: 2 Linguagem: Inglês

10.1080/09398368.2006.11463619

0939-8368

N. Vishwanathan, Venkataramanan Ramanarayanan,

Induction Heating and Inverter Technology

SummaryHigh voltage power supplies for radar applications are investigated, which are subjected to high frequency pulsed load (above 100 kHz) with stringent specifications (regulation < 0.01%, efficiency >85%, droop < 0.5 V/micro-sec.). As good regulation and stable operation requires the converter to be switched at much higher frequency than the pulse load frequency, transformer poses serious problems of insulation failure and higher losses. The solution to this problem as a single stage converter is very difficult. In converters operating at high voltage and high frequency, the insulation failure of high voltage transformer is very common. Skin and proximity effect result in higher power losses. Because of high turns ratio, the winding capacitance results in delays and current spikes. Hence a two-stage converter has been proposed. It isolates the HV transformer from high frequency requirement of the regulation. Its block diagram is shown in the following figure. One stage of it, namely, Base power supply(BPS), operates at low frequency and produces majority of the output voltage and power. The other one, namely, fast power supply (FPS), operating at high frequency and low output voltage supplies the remaining power and takes care ofthe transient variations of line and load and provides the required regulation. The final output voltage is obtained as sum of the outputs of BPS & FPS. Each of the BPS & FPS use phase modulated-series resonant converter as the power-processing unit with zero voltage switching (ZVS). This topology also allows load frequency variation over a certain range.Key Words: High-voltage DC power suppliesresonant converterpulsed load Additional informationNotes on contributorsNeti VishwanathanNeti Vishwanathan received his B.Sc(Engg.) degree in electrical engineering from Dayalbagh Educational Institute, Agra, India, in 1990, M.Tech. degree in electrical machines and industrial drives from REC, Warangal, India in 1992, and the Ph.D. degree from Indian Institute of Science, Bangalore, India, in 2004. He is currently working as a Lecturer in the Dept. of Electrical Engg, NIT, Warangal, India. His areas of interest are switched mode power conversion and electrical drives.Venkataramanan RamanarayananVenkataramanan Ramanarayanan received his B.E. degree from the University of Madras, Madras, India, in the year 1970, the M.E. degree from the Indian Institute of Science, Bangalore, India in 1975, and the Ph.D. degree from the California Institute of Technology, Pasadena, in 1986. He is currently a Professor in the Department of Electrical Engineering at the Indian Institute of Science. He has held positions in Industry as Senior Design Engineer, M/s Larsen & Toubro Ltd., Mumbai (1970–79) and Chief of R&D, NGEF Ltd., Bangalore (1979–82). His areas of interest are power electronics, industrial drives, switched mode power conversion, electromagnetics, and power quality issues. He is a consultant to several industries in related areas.