Zero calibration method and system for rotary transformation of permanent magnet synchronous motor along with different rotating speeds

The invention discloses a zero calibration method and system for a permanent magnet synchronous motor rotating along with different rotating speeds, and relates to the technical field of new energy electric vehicle driving motors. The method comprises the following steps: S1, pre-positioning the position of a rotor and determining an initial zero value of a rotary transformer; s2, controlling the driving motor to reach a preset rotating speed; s3, zero-current control is implemented through the controller so that the rotating speed of the motor can be freely decreased; s4, the target voltage is kept to be zero by adjusting the zero value of the rotary transformer; and S5, recording the zero values of the rotary transformer at different rotating speeds, and fitting a curve to complete calibration. According to the technical scheme of the invention, high-precision rotary transformer zero angle calibration can be realized without additional rack resources, the complexity of the calibration process is reduced, an