MOTOR CONTROLLER AND AIR CONDITIONER

摘要

PROBLEM TO BE SOLVED: To appropriately protect a switching element from thermal destruction.

SOLUTION: A motor controller 11A performs drive control of a three-phase synchronous motor 15 by using a three-phase inverter circuit 17A which has a plurality of switching elements and converts DC power to three-phase AC power. The motor controller 11A comprises: a junction part temperature detection part 21 for detecting junction part temperature related to the switching elements; a current detection part 19 for detecting current flowing in the three-phase inverter circuit 17A; and an overcurrent stop control part 23 for performing control of stopping driving the three-phase synchronous motor 15 when the current detected by the current detection part 19 has exceeded an overcurrent threshold which is set in advance and is a criterion in the case of determining whether the current is overcurrent or not. The overcurrent threshold is set so as to have a temperature characteristic variable depending on variation in the junction part temperature so that the overcurrent threshold is high in a region whose junction part temperature detected by the junction part temperature detection part 21 is low, and is low in a region whose temperature is higher than that of the region whose junction part temperature is low.

COPYRIGHT: (C)2013,JPO&INPIT