Load driving device with failure detection

A load driving device comprising:

• an inverter circuit including a pair of upper and lower arms provided to each phase of three or more multiple phases, where a switching element is provided to each of the upper arm and the lower arm of each phase;
• and
• a controller configured to control each of the switching elements to repeatedly turn on and off,
• wherein a diode is connected in parallel to each of the switching elements in an opposite direction with respect to a power source, and
• wherein a current is supplied to a load from the power source via the inverter circuit based on an on state and off state of the each switching element,
• wherein the load driving device further comprises:
• a failure detection unit configured to detect a failure of at least one of the switching elements corresponding to a faulty switching element, and a failure of the diode that is connected in parallel to the faulty switching element, and
• wherein the controller:
• performs, when the failure detection unit detects the failure according to which the faulty switching element provided to one of the upper and lower arms of a certain phase is not conducting, but does not detect the failure according to which the diode that is connected in parallel to the faulty switching element is not conducting in a forward direction, control for each switching element of other phases and control for a switching element which is paired with the faulty switching element of the certain phase to repeatedly turn on and off, and
• maintains, when the failure detection unit detects the failure according to which the faulty switching element provided to the one of the upper and lower arms of the certain phase is not conducting, and detects the failure according to which the diode that is connected in parallel to the faulty switching element is not conducting, a switching element of the certain phase, which is paired with the faulty switching element, in an off state, and performs control for each switching element of other phases to repeatedly turn on and off.