Winding switching device and winding switching method for three-phase AC motor

摘要

PPROBLEM TO BE SOLVED: To provide a coil switching device for a three-phase AC motor, which switches coils without reducing a current command for the motor even while changing the speed of the motor, reduces a shock at the coil switching and obtains a smooth speed. PSOLUTION: The coil switching device for the three-phase AC motor has: a coil-selection synchronous unit 34 synchronizing a coil selection signal with a synchronizing signal and outputting the synchronized coil selection signal; a coil-switching sequence control section 30 performing an arithmetic control operation for a coil-switching sequence on the basis of the synchronizing signal, a speed mode and an arithmetic-operation completing signal and outputting an arithmetic-start signal, a constant switching signal and the coil selection signal; and a voltage-command synchronous machine 33 synchronizing a phase-voltage command with the synchronizing signal and outputting the synchronized phase-voltage command. PCOPYRIGHT: (C)2010,JPO&INPIT