POWER CONVERSION APPARATUS

摘要

An object is to determine a current limit level most suitable to a drive system for a hybrid automobile or an electric automobile so that a DC-side capacitor is prevented from being broken down when an inverter is stopped in an emergency during high-speed rotation of a motor. A controller (60A) for switching an inverter (40) includes: a current detecting unit (61) ; an overcurrent level determining unit (63) which determines an overcurrent level for stopping the inverter (40) in accordance with a value corresponding to the number of revolutions of a motor (M); a current comparing unit (64) which compares a detected output current value of the inverter (40) with the overcurrent level; and a gate signal generating unit (65) which generates a signal for turning off all semiconductor switching devices of the inverter (40) when the current comparing unit (64) makes determination that the detected output current value has reached the overcurrent level. In addition, the overcurrent level is lowered as the number of revolutions of the motor (M) increases.