Control Method of Three-Phase Bidirectional Voltage Source Rectifier

摘要

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-phase rectifier circuit, in which an AC power source (Va, Vb, Vc) input with a phase difference of 120 W through the terminals (a, b, c) is rectified and applied to a load side. Switching transistors Q1 and Q4 driven in accordance with the switching signals S1 and S4 between the load sides, and switching transistors Q3 and Q6 driven in accordance with the switching signals S3 and S6 between the terminal b and the load side. Is connected between the terminal c and the load side of the switching transistors Q5 and Q2 which are driven in accordance with the switching signals S5 and S2. The transistors Q1, Q3 and Q5 are connected to the voltages Va and Vb. Controls only the transistor connected to the phase with the largest phase voltage of Vc conducting and the other two transistors to be off; Transistors Q2, Q4 and Q6 control only the transistors connected to the phase with the smallest phase voltages of voltages Va, Vb and Vc to conduct and the other two transistors to be off.;That is, in the present invention, there is an advantage in that there is no switching loss by controlling the driving of transistors acting as a switch by comparing only the size of each phase of a three-phase AC power supply, and turning the transistor on or off when the voltage across the transistor is zero.