Method and apparatus for controlling rotor position of electric machine

The invention is applicable to the motor technical field and provides a motor rotor position control method and a device, the method comprises the following steps: the collected correct rotor position is compared with the rotor position calculated when in error, whether the difference value between the collected correct rotor position and the rotor position calculated when in error exceeds the given range of the motor rotor position change is judged; if so, the collected correction rotor position of this time is deserted; the total value of the rotor position calculated when in error and the maximum value of the given range of the motor rotor position change is calculated and used as a correction value to control the operation of the motor. The method and the device solve the problem in the prior art that when errors happen to the motor rotor position continuously, the collected correct rotor position is directly used for controlling the motor, thus causing the change rate of the current to be overlarge and damaging power devices.