| 摘要 |
PURPOSE:To accurately reset the voltage after releasing the overcurrent limit by turning ON or OFF a switch inserted into a voltage control loop which controls an inverter with the detected output current value passed through a delay unit. CONSTITUTION:The output voltage of an inverter 1 is detected and is compared with the voltage of a setter 5, is inputted through a switch 6 to a PI regulator 7 to control a firing angle regulator 8, the output current is compared with the value of a current limit value setter 11 to turn ON or OFF the switch 6, and is controlled through a timer 13 to apply no delay when the OFF signal is applied and to apply the delay when the ON signal is applied. Accordingly, the inverter 1 is controlled in the voltage control loop at the normal time and in the current control loop at the overcurrent state generating time, and the skip due to the delay in the detection of the stored voltage value in a PI regultor 7 is prevented at the time of releasing the overcurrent limit, thereby accurately resetting to the original voltage. |
