MALFUNCTION DIAGNOSIS METHOD, MOTOR CONTROL METHOD, POWER CONVERSION DEVICE, MOTOR MODULE, AND ELECTRIC POWER STEERING DEVICE

摘要

This malfunction diagnosis method involves executing, for each of a plurality of switching elements: a step for determining whether the voltage at the switching element when the switching element has been controlled to be in an on state is at least a prescribed voltage; a step for detecting, when the voltage at the switching element is at least the prescribed voltage, the amount of time that the voltage at the switching element is at least the prescribed voltage; a step for determining whether the detected amount of time is at least a prescribed about of time; a step for counting, when the detected amount of time is at least the prescribed amount of time, the number of times that the detected amount of time has been at least the prescribed amount of time; and a step for determining whether a counted total number of times is at least a prescribed number of times. Of n phases, the phases of windings that are connected to switching elements for which the counted total number of times is at least the prescribed number of times are determined to be malfunctioning phases.