Patent ID: 7245094

Claim:
A power output apparatus that outputs power for driving, said power output apparatus comprising: multiple motors that are capable of outputting power for driving; multiple driving circuits that individually have switching elements and respectively drive the multiple motors by switching operations of the switching elements; a power demand setting module that sets a power demand in response to an operator's operation; and a control module that, when all the multiple driving circuits are in a normal state, drives and controls the multiple driving circuits to ensure output of a power equivalent to the set power demand from the multiple motors, when one of the multiple driving circuits is in an abnormal state, said control module driving and controlling the multiple driving circuits to restrict output of the power from a motor driven by the driving circuit in the abnormal state, prior to restriction of a switching frequency of the switching elements included in the driving circuit in the abnormal state and to ensure output of the power equivalent to the set power demand from the multiple motors; and wherein said control module drives and controls a driving circuit heated to at least a preset first temperature among the multiple driving circuits, as the driving circuit in the abnormal state; wherein when one of the multiple driving circuits is heated to the preset first temperature, said control module drives and controls the multiple driving circuits to restrict output of the power from a motor driven by the driving circuit heated to the preset first temperature and to ensure output of the power equivalent to the set power demand from the multiple motors, when one of the multiple driving circuits is heated to a preset second temperature, which is higher than the preset first temperature, said control module driving and controlling the multiple driving circuits to restrict the switching frequency of the switching elements included in at least the driving circuit heated to the preset second temperature and to ensure output of the power equivalent to the set power demand from the multiple motors; and wherein said control module drives and controls the multiple driving circuits to enable a motor driven by a driving circuit in the normal state to compensate for an insufficiency of the power caused by the restriction of the output of the power from the motor driven by the driving circuit in the abnormal state.