Research On Sliding Mode Control Method Of Nonlinear DC Micro-Grid Active Power Filter

A large number of nonlinear components lead to ripples in the DC micro grid. Therefore, sliding mode control, which is more suitable for nonlinear systems, is applied to active filters to improve the power quality of the micro grid. The traditional sliding mode control has some problems such as chattering and slow convergence, that a DC active power filter (DC-APF) ripple suppression method based on double power fixed-time sliding mode control is proposed. The integral sliding mode surface is designed to avoid the shortcomings of the normal sliding mode surface that the initial state cannot be guaranteed to be on the sliding mode surface, and to enhance the robust performance; the introduction of the double-power reaching law enables the system to reach a fixed time convergence without considering the initial state. Then, double power fixed-time sliding mode control and PI control are applied to DC-APF respectively, and the comparative simulation is carried out to verify that the proposed control method has faster convergence speed, effectively reduces system chattering, and can effectively suppress the system ripple.