INVERTER AIR CONDITIONER FOR PROPERLY DRIVING FIRST AND SECOND SWITCHING ELEMENTS

摘要

PURPOSE: An inverter air conditioner is provided to suppress harmonics with obtaining a high power factor by properly driving first and second switching elements, resulting in improved maximum ability and efficiency of an air conditioner. CONSTITUTION: A rectifier circuit(2) having two input terminals and two output terminals is connected to AC(Alternating Current) power supply(1) through a reactor(3) at one side of the input terminals, and converts an AC-power supply voltage into a DC(Direct Current) voltage. Condenser circuits(4,5) are formed of a plurality of condensers connected in the serial, and connected between two output terminals of the rectifier circuit. A converter includes a first switching element(7) connected between one input terminal of the rectifier circuit and one connection point between the condensers in the condenser circuits, and a second switching element(8) connected between the other input terminal of the rectifier circuit and the connection point in the condenser circuits. A power-source phase detection element(14) detects a phase of the AC power supply. A control element(9) controls the first and second switching elements based on a signal of the power-source phase detection element. An inverter(10) is formed of an inverter part converting a DC output voltage of the converter into an AD voltage, and a revolving-speed control element controlling an inverter part output frequency or inverter part output voltage by changing a conduction ratio to the inverter. A compressor(11) is driven by the inverter.