Model-free Predictive Current Control Combined with Sliding Mode Voltage Control for Wind Power Grid-connected System

Abstract

In the context of global energy transition towards low-carbonization, direct-drive permanent magnet synchronous wind power generation systems have become one of the mainstream power generation equipment due to their unique advantages. However, traditional control algorithms are difficult to cope with the complex operating conditions of the grid-side converter. This paper aims to improve the grid connection control algorithm of the direct-drive wind power system. It proposes a collaborative algorithm based on sliding mode control (SMC) for DC link voltage control and model-free predictive control (MFPC) for current control. Additionally, a discrete extended state observer (DESO) is designed to observe the unknown state variables in the system to avoid the influence of model mismatch. By comparing the simulation results of different algorithms of the control system under internal and external disturbances, it is verified that the proposed algorithm can more effectively track the d-q axis target current and stabilize the DC link voltage. The proposed method can help wind turbine generators operate efficiently in harsh environments, and has certain theoretical and engineering value for improving the grid connection performance of direct-drive wind power and promoting the consumption of new energy.