AC side switched active filter based high performance three-phase boost rectification with energy recovery snubber

Input current and power factor improvements of single and three-phase rectifiers by switch mode regulators are usually achieved by switching the output of rectifier´s diode bridge. In this paper a three phase boost rectifier is proposed which is switched at the input side by one three phase bidirectional switch. The input switching makes input current switched at high frequency, which is then filtered by a small filter to get low THD input current at near unity power factor. Direct input current switching ensures current displacement with input voltage to be unity. This makes the control logic simpler for maintaining high input power factor and high input power factor. An energy recovery snubber is proposed which makes the efficiency high. A comparison of the proposed input side switched active filter based boost rectifier is made with the conventional boost regulated three-phase rectifier. Results show that the performance of the proposed boost rectifier is superior to the conventional boost rectifier in terms of low input current THD and high input power factor. The rectifier operates at a line voltage of 400 Volts with a power rating of 5 kW.