Capacitor Selection Method in PV Interfaced Converter Suitable for Maximum Power Point Tracking

Capacitor is connected primarily between photovoltaic (PV) panel and power electronics converter (PEC) to suppress input voltage ripple and filter ripple current. However, this capacitor creates an error in maximum power point tracking (MPPT) for a fixed step algorithm under rapidly changing environmental conditions if not selected properly. Therefore, the capacitor value selection along with maximum sampling rate determination is crucial for achieving error-free MPPT. A comprehensive analysis is carried out to prove the dependence of capacitor value on MPPT performance under irradiation and temperature variation. The analysis also includes the effect of ripple power on capacitor value selection when a PV interfaced converter is connected to the grid. Finally, the capacitor value and the sampling rate of PV interfaced PEC are determined. Simulation and experimental results confirm the theoretical findings.