The maximum power point tracking method based on Lagrange multiplier

Grid photovoltaic system (PV) is a nonlinear system, PV is easily affected by the grid work and the meteorological factors, and power output is volatile. Aiming at misjudging and tracking slow the problem of incremental conductance method, PV array model was built using MATLAB\ Simulink; the Lagrange multiplier algorithm was improved and optimized by using tracking differentiator based on Lagrange multipliers method in analysis. The simulation results showed that the Lagrange multiplier algorithm could rapidly and accurately tracking photovoltaic system maximum power using tracking differentiator after transformation, it could effectively inhibit various disturbances and reduce the misjudgment rate, the dynamic performance and stability of the system were better than the conventional incremental conductance method, thereby improving the robustness of the system.