In such a product that torque of a motor is continuously generated when a rotation number of the motor is nearly equal to zero, since an output voltage is kept at a constant value in accordance with a rotation position of the motor, such a condition that currents are concentrated in a specific element are maintained. As a result, a temperature of the specific element is increased, so that there are problems that a temperature fail of an inverter apparatus may readily occur, and thus, lifetimes of elements are lowered. In a power converter of a motor drive apparatus, windings are energizing-controlled in such a manner that only 1 phase of a switching circuit is pulse-width-controlled when the motor is under motor locking condition.