POLYPHASE MOTOR DRIVING APPARATUS

PROBLEM TO BE SOLVED: To suppress vibration of voltages and currents of a direct-current power supply, taking advantage of the carrier synchronization technique.SOLUTION: There is provided a polyphase motor driving apparatus comprising: a polyphase motor 1 including an M number of windings and an N phases of windings, where M is an integer of 4 or greater and N is an integer of 4 or greater, the windings being electrically insulated from each other and magnetically coupled to each other; an N number of inverter circuits 11 of a single-phase pulse width modulation system connected to each of the windings and configured to convert a direct-current power into an alternating-current power; and a phase correction circuit configured to shift a phase of a carrier of each control circuit such that a line voltage is switched on with dispersed timing in each of the inverter circuits 11, by repeating a process of shifting a phase of a carrier between a first inverter and a second inverter by a phase angle and shifting a phase of a carrier between a second inverter and a third inverter by a phase angle in each of the inverter circuits 11. In the polyphase motor driving apparatus, the number M of windings is configured to be integral multiples of a phase number N and a number N of inverters. The polyphase motor driving apparatus is connected in parallel to an output of each of the inverter circuits 11 by the number of windings M/N of the polyphase motor 1.