DC-Link Voltage Regulation for Wind Power System by Complementary Sliding Mode Control

Considering the non-rigid transmission connection between the wind turbine and the generator, their angular velocity is inconsistent. A DC-link voltage control model with uncertainties is established by a two-mass inertial model. The system uncertainties increase greatly compared with the single-mass inertial model, which aggravates a DC-link voltage accuracy. To suppress the uncertainties, the complementary sliding mode control (CSMC) is proposed to regulate the DC-link voltage since it has strong robustness. The equivalent controller for the voltage loop is obtained by the conservation principle of AC and DC side power, and the compensation controller for the uncertainties is designed by the saturation function. The CSMC system is analyzed to be asymptotic stability. The simulation and experiment results show that the CSMC system can suppress the system uncertainties, and obtain a more little steady-state error of the DC-link voltage, compared with PI control system.