Patent ID: 11356044

Abstract:
The present invention provides a method for detecting motor initial phase and phase sequence and a system for controlling a permanent-magnet synchronous motor. The method is applied to the system and comprises sequentially acquiring, through an encoder, first displacement data which register the encoder's reading when a rotor spins to a Q-axis, second displacement data which register the encoder's reading when the rotor spins from the Q-axis to a D-axis, third displacement data which register the encoder's reading when the rotor spins from the D-axis to a negative Q-axis and fourth displacement data which register the encoder's reading when the rotor spins from the negative Q-axis to the D-axis; obtaining an initial phase of the motor to be detected according to the second displacement data, the fourth displacement data and the encoder's CPR; and determining the phase sequence of the motor based on the first displacement data, the second displacement data and the encoder's CPR. That is to say, the method can not only automatically detect the initial phase of the rotor, but also the motor wiring phase sequence, and overcome the influence of friction force to improve the initial phase detection precision.