Enhancing performance and power quality in a wind energy conversion system based on permanent magnet synchronous generator through improved 3rd-order super-twisting control

Traditional control methods, including vector control (VC) with proportional-integral (PI) controllers, sliding mode control (SMC), and second-order SMC (SOSMC) employing the super-twisting (ST) algorithm, significantly impact system performance and power quality. However, these techniques are susceptible to internal and external disturbances. This study introduces an improved third-order ST control (ITOSTC) designed for wind energy conversion systems (WECS) that incorporate a permanent magnet synchronous generator (PMSG). ITOSTC addresses issues such as chattering and power ripples by employing a novel sliding surface with continuous smooth switching control. The ITOSTC is designed to regulate the generator speed to align with the desired value during wind variations. Additionally, the proposed ITOSTC manages the grid supply to ensure power injection with a unity power factor. The DC-link voltage is also regulated by the proposed approach. A comprehensive analysis under random wind speed variations assesses the robustness of the suggested approach, with stability verified using Lyapunov theory, considering system uncertainties for enhanced efficacy. Comparisons with a PI regulator and conventional SOSMC reveal the outstanding performance and high robustness of ITOSTC. It improves system efficiency to 96.66 %, surpassing SOSMC (91.22 %) and PI (88.12 %). Furthermore, the designed ITOSTC minimizes grid-injected total harmonic distortion by approximately 55.32 % compared to conventional SOSMC. The outcomes obtained from this study, utilizing MATLAB/Simulink, illustrate the efficacy and success of the proposed approach in various tests conducted on a variable-speed WECS using PMSG, compared to conventional methods.