State-of-the-art power electronics systems for solar-to-grid integration

Power generated by PV panels is highly vulnerable to uncertain weather conditions, and impedance connected to its terminals. Therefore, to maximize the energy productivity from panels by controlling output impedance, a power electronic converter capable of adopting maximum power point tracking (MPPT) technique is required. This paper includes a comprehensive review of basic and advanced MPPT techniques proposed to address the variations in temperature, irradiance, partial shading conditions. Power processing equipment such as dc/dc converters and inverters are mandatory in extracting power from PV panels and utilizing either for standalone systems or grid integration. Grid integration is a major focus where access to utility line ranging from domestic micro-inverters ( < 300 W) to solar generation ( > MW). A centralized inverter topology interfaces a MW power rating PV farm consisting several parallel strings of series connected PV panels to the grid. This review article contributes on presenting an overview of the state-of-the-art power electronics systems for integration of PV panels to the grid. Various interfacing power electronic architectures covering micro-inverter, central inverter up to modular inverter approach operating at low switching frequency and high switching frequency with resonant and pulse-width modulated (PWM) soft-switching or hard-switching are reported. Various voltage-fed and current-fed multi-level inverters for such architectures are studied and discussed.