Method for measuring direct-axis inductance of permanent magnet synchronous motor

The invention discloses a method for measuring direct-axis inductance of permanent magnet synchronous motor, and belongs to the technical field of electric power and electronic. The method comprises the following steps: firstly, driving the permanent magnet synchronous motor twice by the same control method to achieve no-load steady state operations, wherein in two no-load steady state operation states, amplitudes of driving signals are different, while the frequencies of the driving signal are the same and are smaller than the fundamental frequency of the permanent magnet synchronous motor; secondly, according to currents and voltages of the driving signals in the two no-load steady state operation states, computing to obtain the direct-axis inductance. By the method, the direct-axis inductance of the permanent magnet synchronous motor can be measured relatively accurately, voltage detection equipment and a voltage detection component are not required additionally, and direct-axis positioning of the synchronous motor is not required; the method is simple in operation and strong in robustness.