Study on Photovoltaic MPPT Based on Boundary Layer Variable Sliding Mode Control

In response to the shortcomings of traditional sliding mode MPPT control strategy in photovoltaic maximum power point tracking technology, such as tracking voltage error and chattering, compares and analyzes the shortcomings of traditional sliding mode MPPT control strategy, and proposes a targeted sliding mode control strategy with variable boundary layer. An improved saturation function power-law approach law is established, utilizing the fast convergence of the power-law function and the adaptive adjustment characteristics within the improved saturation function boundary layer. The system position error is controlled by the boundary layer thickness expression, and a segmented adjustment strategy is established at different stages of the approach process, so that the initial state points in the boundary layer move to the equilibrium point of sliding mode control, achieving accurate tracking of the maximum power point of the photovoltaic system. Finally, simulation is conducted using Matlab/Simulink and an experimental platform is built for verification. The results show that the use of a sliding mode MPPT control strategy with variable boundary layers can achieve accurate tracking of the maximum power point of the photovoltaic system, and even under large disturbances, it can still achieve fast tracking and smooth output of the maximum power.