Voltage Sliding Mode Control of Autonomous Single Phase Microgrid Based on Second Order Generalized Integral Algorithm

Abstract

Aiming at the inherent characteristics of traditional droop control of autonomous microgrid, which can cause the voltage amplitude and frequency deviation and the poor anti-disturbance capability of inner loop voltage control. A sliding mode control method based on second order generalized integral (SOGI) is proposed. Firstly, two phase orthogonal output voltage and current signals are reconstructed by the second order generalized integrator quadrature signals generators (SOGI-QSG) to realize independent control of active and reactive components. Then, in the reference voltage droop control loop, the second order generalized integral (SOGI-FLL) bus voltage frequency and amplitude estimation model based on frequency locked loop is used to improve the traditional droop control, so that the droop reference voltage is closer to the expected nominal value. Finally, a sliding mode voltage controller is designed for inner loop voltage control, so that the output voltage of inverter system can track its reference voltage quickly and accurately, and the robustness of the system can be enhanced. The experimental data shows that the method can ensure the stable output voltage, the output voltage total harmonic distortion is reduced, and has good dynamic response speed and has strong anti-interference of load.