| 摘要 |
PURPOSE:To rapidly restart an inverter after recovery of the inverter by employing the remaining voltage of a motor when the motor is operated in the vicinity of rated speed and employing a power source voltage after the recovery at the low speed operation time to charge a commutation condenser. CONSTITUTION:In case that an instantaneous stop occurs in a motor at the vicinity of a rated speed, i.e., when the remaining voltage of the motor is the prescribed voltage or higher, a firing signal is applied to a thyristor U to utilize the remaining voltage, and a switch 66 is closed. Thus, a commutation condenser 5 is charged. In case that an instantaneous stop occurs in the motor at the low speed time, i.e., when the remaining voltage of the motor is the prescribed value or lower, a switch 65 is closed to utilize the power source voltage. Thus, the condenser 5 is charged. In this case, when the charging time constant which is determined by a resistor 61 and the condenser 5 is selected to a small value, the charging time is shortened, and the inverter can be restarted in a short time after the recovery. |
