| 摘要 |
Even though the protection function of an inverter device (210) for stopping the inverter is originally designed to be actuated in case of an abnormality state such as an overcurrent condition or a drop in control power supply voltage, it is sometimes performed because of the false detection of an overcurrent detection circuit (237), which is caused when switching noises generated in the inverter or the power circuit are overlapped with an overcurrent detection signal. If the protection function is actuated to stop the inverter device (210), although the protection function has been actuated due to the false detection of an overcurrent, it is still difficult to diagnose the cause of the actuation of the protection function, that is, it is not clear whether the inverter (221) has stopped because of the failure in the IPM or the driver circuit. Therefore, an inverter device (210) of the present invention includes a DC detection circuit (233) for detecting a DC flowing in the inverter (221), an overcurrent detecting circuit (237) for detecting an overcurrent if the detected direct current is not less than a set value, and protection means for stopping the inverter if the detected DC is not less than a second set value greater than the set value. |
