基于VSG并网逆变器的模糊滑模控制策略研究

Research on Fuzzy Sliding Mode Control Strategy Based on VSG Grid-Connected Inverter

为改善微网逆变器性能,提出基于虚拟同步发电机(VSG)技术的模糊滑模控制(FSMC)策略。在上层控制中,采用VSG技术为底层控制提供参考电压,并为系统提供必要的惯性和阻尼;在底层控制中,采用滑模变结构控制(SMC)算法提高系统的鲁棒性和动态性,根据输出电压与参考电压的差值构成三阶滑模面,控制部分采用等效控制和切换控制;为减弱滑模变结构控制带来的“抖振”,在切换增益环节采用模糊控制算法。最后, MATLAB/Simulink仿真结果验证了所提控制策略的正确性和有效性。

In order to improve the performance of the micro-grid inverter, a fuzzy sliding mode control (FSMC) strategy based on virtual synchronous generator (VSG) technology is proposed. In the upper layer control, the VSG technology is used to provide the reference voltage for the bottom layer control and provide the necessary inertia and damping for the system. In the bottom layer control, the sliding mode variable structure control (SMC) algorithm is used to improve the robustness and dynamics of the system. A third-order sliding mode surface is formed according to the difference between the output voltage and the reference voltage, and the control part adopts equivalent control and switching control. To reduce the ‘chattering’ brought by the SMC, a fuzzy control algorithm is adopted in the switching gain step. Finally, both the correctness and validity of the proposed control strategy are vertified by the simulation results in MATLAB/Simulink platform.