CONTROL UNIT OF POLYPHASE AC CURRENT

PROBLEM TO BE SOLVED: To allow the actual current value of each phase of polyphase AC current having the number of phases exceeding three phases follow the current instruction value of respective phase without phase delay. SOLUTION: In order to PWM-control a 5-phase motor 2, for example, through an inverter 1, there are provided a coordinate converter 7 which converts, for coordinate transformation, phase currents i1-i5 to the current component on an orthogonal rotation coordinate and calculates at least two current components id and iq being AC current in a normal state, current controllers 8 and 9 to feedback-control the acquired current components, and a current controller 13 for direct feedback controlling of the current of respective phase. The inverter 1 is controlled using a synthetic value of the voltage command from the current controllers 8 and 9 and that from the current controller 13. COPYRIGHT: (C)2005,JPO&NCIPI