Motor control method

A motor control method used for a synchronous motor, wherein a position sensor is coupled to the synchronous motor, and the motor control method comprises:

• adjusting a voltage component of an estimated voltage command to a steady-state voltage value;
• performing a coordinate axis conversion on another voltage component of the estimated voltage command and the steady-state voltage value to generate a two-axis voltage command;
• generating a three-phase excitation current to drive the synchronous motor to a rotating position and stop based on a DC excitation voltage command and the two-axis voltage command;
• retrieving the three-phase excitation current to calculate an estimated current signal, wherein a current component of the estimated current signal corresponds to the steady-state voltage value;
• obtaining a measured value of the rotating position through the position sensor when determining that the current component is not maintained at a steady-state current value;
• adjusting the another voltage component of the estimated voltage command based on the measured value of the rotating position, so that the current component corresponding to the steady-state voltage value is maintained at the steady-state current value;
• and
• calculating an effective inductance of the synchronous motor based on the steady-state voltage value, the another voltage component of the estimated voltage command, the steady-state current value, and another current component of the estimated current command when determining that the current component is maintained at the steady-state current value.