| 摘要 |
PURPOSE:To compensate an output-voltage drop in response to the magnitude of the output currents of an inverter without detecting the output signal of the inverter by compensating the output-voltage drop of the inverter in response to the magnitude of the output currents of the inverter. CONSTITUTION:A PWM inverter 1 has three pairs of transistors as switching elements on the positive side and the negative side, receives a pulse width modulation signal from a PWM pulse computing element 9, converts DC voltage into three-phase AC voltage, and supplies an induction motor 2 with converted three-phase AC voltage. An output-voltage drop to the AC output currents of the PWM inverter 1 is changed in response to the magnitude of output currents. Compensating voltage Vf is acquired in response to the magnitude of output currents and added to the three-phase AC voltage command signal V of the stator coordinate system of the AC motor 2, thus compensating the voltage drop of the PWM inverter 1 with on-delay. Accordingly, the generation of a torque ripple can be prevented. |
