| 摘要 |
PROBLEM TO BE SOLVED: To drive a load without operation of a circuit breaker under the condition where a multi-phase AC power supply is unbalanced by effectively using an electrical power of the power supply even in such condition. SOLUTION: A control circuit 20 estimates the input maximum current under the condition that a 3-phase AC power supply 10 is unbalanced, by executing a predetermined calculation based on a ripple voltage obtained as a voltage detected value Vm after the rectification and a current detected value Im as a current value flowing into a resistor 14. A control signal is applied to an inverter 15 to control the estimated maximum current within the allowable range of the circuit breaker in order to drive a motor 30. |
