| 摘要 |
PURPOSE:To prevent the occurrence of deviation in an inverter output current waveform by detecting the state of continuity between inverter switching elements, counting the continuity time and giving the result as a compensation signal for voltage command value. CONSTITUTION:A sensor 14 detects the state of continuity between elements at the positive polarity side of two switches connected in series of an inverter 3 and inputs a detection signal to a counter 15. The counter 15 counts the conducting time between switches by a detection signal and inputs the counted value (v) to a current control arithmetic unit (IC) 11. Therefore, the IC 11 performs the current control arithmetic operations from a current command value (i')of speed control arithmetic unit 8, a digital value (i)of an A/D converter 10 and a count value V of the counter 15 and calculates a voltage command value (v). That is, compensation calculation for dead time is performed by the current value (v) for the voltage command value obtained from the current command value (i') and the digital value (i), a final voltage command value (v') is obtained, and the voltage command value (v') is input to the PWM equipment 12. |
