| 摘要 |
PURPOSE:To eliminate torque ripple of a motor occurring at phase switching time of PWM signal by providing a phase pattern converting means, a phase pattern memory means, means for storing phase pattern produced two times before, and a PWM converting means. CONSTITUTION:A commutator signal detected from a motor 1 is converted through a phase pattern converting means 4 into current time phase pattern (a). A previous time phase pattern (b) is outputted from a previous time pattern memory means 5 and a two times before pattern (c) is outputted from a two times before pattern memory means 6. Current pattern (a), previous pattern (b) and two times before pattern (c) are then added and provided as an adding phase pattern to a PWM converting means 3 together with a current command value thus producing a PWM signal having ON-OFF timing lag. When thus produced PWM signal is provided to an inverter circuit 2 for controlling the motor 1, phase is shifted without decrease of total current flowing to the motor 1. |
