PROTECTING METHOD OF INVERTER

摘要

PROBLEM TO BE SOLVED: To provide an apparatus which detects that a power source is connected with a motor terminal of an inverter and prevents breakdown of a power element. SOLUTION: When a power source terminal is correctly connected with a motor terminal at the closing of power source, a current flowing in a regenerative power discharge circuit 4 flows in the order of a power source - a converter part 1 - a converter current detecting circuit 7 - the regenerative power discharge circuit 4 - a rush current detecting circuit 9 - the converter part 1 - the power source. When the power source terminal is inversely connected with the motor terminal, a current flowing in the regenerative power discharge circuit 4 flows in the order of the power source - an inverter part 2 - the discharge circuit 4 - the inverter part 2 - a motor current detecting circuit 8 - the power source. Thereby inverse connection of the power source can be judged by detecting whether the current of the discharge circuit 4 flows through the converter part current detecting circuit 7, the rush current detecting circuit 9 and the motor current detecting circuit 8.