Solar PV Transient Mitigation Using Superimposed Sliding Mode-Perturb and Observe MPPT under Varying Irradiation Conditions

Varying weather specifically temperature and irradiation have a significant impact on Solar Photo Voltaic (SPV) output performance and efficiency. Both the output voltage and power are unstable due to the unwanted solar fuel variation. Therefore, Maximum Power Point Tracking (MPPT) plays an important role in the case of SPV. Although different MPPT techniques are imposed to mitigate the above-said issues, the Perturb and Observe (P&O) is unique in its operation and simple to design. But when P&O comes under a sudden large variation of solar parameters, it fails to track and move away from the Maximum Power Point (MPP). A sliding mode controller superimposed with conventional P&O known as Superimposed Sliding Mode Controller-P&O (SISMC-PO) is proposed in this paper that improves the tracking accuracy and tries to minimize the transient disturbance during the rapid change in irradiation. Input side capacitor current and error in SPV voltage with reference voltage are taken as the input to the SMC whereas solar voltage and current are taken as the input to the P&O MPPT. SISMC-PO produces highly efficient and robust control of the switching frequency with a suitable step size that drives the switch of the DC-DC boost converter which is tested and verified by MATLAB/SIMULINK.