POWER SUPPLY APPARATUS FOR INVERTER

摘要

A power supply apparatus for inverters is provided to reduce conduction loss and switching loss due to current by operating the power supply apparatus in a power factor compensating mode and an inverter mode which counteract to each other. A power input terminal(10) supplies commercial AC power. An inductor has an energy accumulating path for the AC power from the power input terminal(10). Transistors(Q1,Q2) are series-connected to the inductor. Transistors(Q3,Q4) are parallel-connected to the transistors(Q1,Q2) and convert the AC power to a DC signal. A battery(BT) is parallel-connected between the transistors(Q1,Q2) and the transistors(Q3,Q4) and charges DC voltage according to switching operations of the transistors(Q1-Q4). A capacitor(C2) is parallel-connected to the battery(BT) and reduces ripples voltages. Transistors(Q5,Q6) are parallel-connected to the transistors(Q3,Q4) and convert the DC signal to the AC power. One end of a transformer(T2) is connected to the transistors(Q5,Q6) and the other end of the transformer(T2) is connected to the inductor. A controller(40) outputs switching signals to gate terminals of the transistors(Q1-Q6) according to variation of source voltage and current of the power input terminal(10).