Winding switching device for three-phase AC motor drive system

摘要

PPROBLEM TO BE SOLVED: To provide a coil switching device of a three-phase ac motor which coil switching device substantially reduces conduction losses to achieve high efficiency. PSOLUTION: The coil switching device of a three-phase ac motor drive system includes an electrical coil switching unit (3) which short-circuits an intermediate tap of each of phase coils in response to a control signal from an inverter, and a mechanical coil switching unit (15) which short-circuits a winding-end terminal of each of phase coils in response to a control signal from the inverter. PCOPYRIGHT: (C)2010,JPO&INPIT