Control apparatus for rotary electric machines

A control apparatus for a rotary electric machine with terminals receiving power from a DC power supply with positive and negative terminals, comprising:

• a DC-AC converting circuit provided with serially connected circuits each having a high-potential-side switching element and a low-potential-side switching element, the high-potential-side and low-potential-side switching elements selectively connecting the terminals of the rotary electric machine to the positive and negative output terminals of the power supply for controlling a controlled variable of the rotary electric machine;
• a connecting/disconnecting circuit arranged to be electrically opened and closed between the DC-AC converting circuit and the power supply to electrically connect and disconnect an electric path connecting both the DC-AC converting circuit and the power supply;
• current detecting means that detects a current passing in the rotary electric machine;
• determining means that determines whether or not the high-potential-side and low-potential-side switching elements have a malfunction which is a short-circuit;
• and
• failsafe performing means that turns OFF all the switching elements in the DC-AC converting circuit when the determining means determines that the high-potential-side and low-potential-side switching elements have the malfunction;
• open/close control means that makes the connecting/disconnecting circuit open when the determining means determines that the high-potential-side and low-potential-side switching elements have the malfunction;
• turning-on means that turns ON a switching element belonging to part of the high-potential-side and low-potential-side switching elements while avoiding a state where potential at all the terminals of the rotary electric machine become the same potential, when the determining means determines that the high-potential-side and low-potential-side switching elements have the malfunction;
• and
• identifying means that identifies a location at which the short-circuit occurs, based on changes in the current detected by the current detecting means in response to turning ON the switching element by the turning-on means, the changes in the current being at least one of a reduction in deviation of the current from a zero point and a reduction change in an absolute value of the current.