A three-phase boost AC-AC voltage converter

Abstract

A two bi-directional switch based three-phase boost AC voltage regulator is presented in this paper. The operational principle of the proposed three-phase regulator is a direct consequence of using two three-phase bi-directional switches in the boost converter topology. The topology has reduced number of switches for a three-phase AC voltage regulator having output voltage regulation, input current shaping and power factor improvement capability. It provides opportunity for simple control technique to be adopted. In this paper output/input voltage feedback and boost inductor average current tracking method is used for controlling the regulator. Reduced number of switches allows simple control circuit, less switching loss, reliable operation and low cost. Steady state analysis and simulation results of close loop control of the proposed converter are presented in this paper. The average inductor current tracking control shows acceptable regulation of the converter output voltage. During sudden variation of load or input voltage the controller adjusts the duty cycle to recover to the desired output voltage. Experimental investigation of the converter without any feedback control is also described.