Abstract: A long cable transmission model is established to solve this problem,the generation mechanism of motor terminal overvoltage is explored,and over-voltage suppression strategy with adaptive control is proposed. The disturbance of system impedance parameters eliminated,and the converter output voltage is adjusted to suppress the motor terminal over-voltage. According to the simulation of the parameters of the direct-drive permanent magnet wind power generation system,the results show that the adaptive suppression strategy can effectively suppress the o ver-voltage of the motor terminal,shorten the overshooting time of the voltage overshoot,and have strong robustness to the disturbance of the system impedance parameters,thereby improving the reliability of the long drives system.