| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a general-purpose AC motor controller that detects a current highly accurately and responds to requirements for a drive controller of the AC motor even when an intermediate phase of a voltage command value is close to the maximum phase or the minimum phase, so that it is difficult to measure a current, when an AC motor is driven by a three-phase PWM inverter which operates on a direct current and a current flowing in the AC motor is measured by a single current sensor. <P>SOLUTION: This AC motor controller is constituted of an AC motor current detection portion, which calculates each three-phase current in the AC motor with measurement results from a DC current measuring means; a three-phase voltage command calculation portion, which calculates a three-phase voltage command given from the three-phase currents to the AC motor; and a three-phase PWM waveform creation portion, which has a carrier wave generation portion which generates either 1, 2 or 3 carrier waves having a constant interval and generates a three-phase PWM inverter control signal by comparing a level between three-phase voltage reference signals of U-phase, V-phase, W-phase constituting the three-phase voltage command calculated by the three-phase voltage command calculation portion and the carrier waves generated by the carrier wave generation portion. <P>COPYRIGHT: (C)2008,JPO&INPIT |
