Current Measurement Error Compensation Method for Permanent Magnet Synchronous Motor Drive System Based on Current Ripple Information Extraction

The accurate measurement of current feedback is a key factor for the optimal operation of permanent magnet synchronous motor ( PMSM ) drive system. In the actual control system. The temperature drift, aging, nonlinearity and other factors of the sensor and the related regulating circuit will produce errors in the current measurement. When the current frequency is equal to the power frequency, the current measurement deviation will lead to torque and speed ripple, which will affect the control performance of the permanent magnet synchronous motor. In this paper, the influence of current measurement offset error is analyzed, and the influence of closed-loop control on current ripple amplitude is further studied. It should be emphasized that the traditional derivation may not be valid when considering the influence of closed-loop control. Aiming at this problem, a current measurement error compensation method for permanent magnet synchronous motor drive system based on current pulsation information extraction is proposed. This method can actively identify and compensate the current ripple generated during the operation of the motor, and use the closed-loop control strategy to reduce the torque and speed ripple caused by the current measurement error. It is worth noting that, unlike the traditional method, the scheme proposed in this paper eliminates the requirements for motor shaft inertia or stator resistance parameters. The effectiveness of the proposed algorithm is finally verified by experiments on permanent magnet synchronous motors in CNC machine tools.