| 摘要 |
PURPOSE:To suppress a torque ripple generated in a motor by providing a signal transition period of a state that both a phase excitation signal and a phase switching signal are active at both the signals, and smoothly switching a current for obtaining a revolving magnetic field in a polyphase AC motor. CONSTITUTION:A signal transition period of a state that both a phase excitation signal (a) and a phase switching signal (b) to be sequentially switched with respect to the rotating speed of a polyphase AC motor 30 are active is provided at the signals (a), (b). When exciting switching elements 21u-21w, phase switching elements 22u-22w in an inverter 20 are switched by the signals (a), (b), polyphase primary voltages are conducted in the motor 30 to be rotatably driven. Further, since the signal transition periods are provided at the signals, switching of the current for obtaining a revolving magnetic field in the motor is smoothened. Thus, a torque ripple can be suppressed to a small value while employing a circuit configuration of a rectangular wave drive type. |
