| 摘要 |
PURPOSE:To always bring a command into coincidence with a real current by controlling an induced voltage compensation value in response to the variation in a main circuit power source voltage. CONSTITUTION:The output signal of an oscillator 5 for generating a sine wave of a frequency proportional to a primary frequency command I' and the added value of a current command I' and the output of an induced voltage compensator 11 are applied to a multiplier 6 to obtain an AC current command. A deviation value between the command and a detection signal detected by a current detector 7 are PWM-modulated by a triangular wave oscillator 9, and the modulated signals are supplied to an inverter 3. Further, a main circuit DC voltage is detected by a voltage detector 12, a PWM conversion gain is divided by the detected value EPN, the value is multiplied by the output signal of the compensator 11 as a compensation signal of the value I'. |
