Patent ID: 8541962
Filing Date: 2013-09-24
Classification: G01R

Abstract:
1. A motor driving apparatus comprising: at least one motor driving unit comprising an inverter coupled between a positive direct current bus line and a negative direct current bus line of a direct current power source, the inverter being configured to convert direct current power into alternating current power to drive an alternating current motor; a low-voltage source coupled between a ground and at least one of the positive direct current bus line and the negative direct current bus line; a current detecting element configured to detect a closed circuit current flowing through a closed circuit of the low-voltage source, the alternating current motor, and a part of the inverter; and an insulation resistance degradation determinator configured to make a comparison between the closed circuit current detected by the current detecting element and a predetermined threshold, and configured to determine, based on the comparison, whether an insulation resistance of the alternating current motor is degraded, wherein the inverter includes a plurality of arm switching elements configured to switch between an open state and a closed state with respect to the alternating current motor, wherein the current detecting element is configured to detect: wherein the motor driving apparatus further comprises an offset removal element configured to obtain a difference between the offset current and the closed circuit current which are detected by the current detecting element, and wherein the insulation resistance degradation determinator is configured to make a comparison between the difference and the predetermined threshold.