Patent ID: 8680794
Filing Date: 2014-03-25
Classification: B60L,H02M,H02P,Y02T

Abstract:
1. A load drive system for driving first, second, and third loads, comprising: first, second, and third three-phase inverters each having an input terminal and an output terminal, the input terminals of the first, the second, and the third three-phase inverters being connected to a direct current power source, the output terminals of the first, the second, and the third three-phase inverters being respectively connected to the first, the second, and the third loads; a first control unit operable to (i) generate a first carrier signal of a sawtooth waveform and (ii) control the first three-phase inverter according to the generated first carrier signal; a second control unit operable to (i) generate a second carrier signal of a sawtooth waveform which is inverted with respect to the first carrier signal and has a same frequency and a same phase as the first carrier signal and (ii) control the second three-phase inverter according to the generated second carrier signal; and a third control unit operable to (i) generate a third carrier signal of a triangular waveform having ramps respectively equal to the sawtooth waveform of the first carrier signal and the sawtooth waveform of the second carrier signal, the triangular waveform either having a same phase as the first and the second carrier signals or being out of phase by half a period relative to the first and the second carrier signals, and (ii) control the third three-phase inverter according to the generated third carrier signal.