Power rectifier with harmonic suppression for supply of refrigerator motor inverter

摘要

A power unit for supplying power to the inverter power supply 45 for the compressor motor 46 of a refrigerator includes an AC power source 1, a bridge rectifier circuit 2 with diodes D1, D2, D3 and D4, an auxiliary capacitor 3 connected in parallel with the output of the rectifier, a serial circuit of a variable inductance 42, 43 and a diode 5 connected between one output of the rectifier and the inverter 45 so that a load current can flow in the forward direction, and a smoothing capacitor 6 connected in parallel with the inverter. The variable inductance includes a first inductance 42 and a second inductance 43, and the inductance can be changed by means of a switch 44 activated by the controller 47. The capacitance of the smoothing capacitor is about 100 times the capacitance of the auxiliary capacitor 3, which serves for the suppression of higher order harmonics during the operation of the power unit.