The Research Of PV Power Optimizer Based On The Control Of Adaptive Voltage

Photovoltaic (PV) power optimizer as an effective way of solving PV shadow, not only saved the energy loss caused by shadow, but also keep high response and smooth transition process in the change of external environment. Considering the large dc voltage range of the inverter, which needs the input capacitance withstand big pressure, we designed a adaptive voltage controller to control the input voltage of the inverter and the output voltage of the power optimizer, which make the input voltage of inverter stable in10%of the rated voltage range.This paper focus on the series structure of the PV array, analyzed the topology, circuit principle, parameter calculation and the principle of optimality, an adaptive voltage control unit was designed, including the MPPT control, the output voltage control of PV power optimizer and the input voltage control of inverter, the control of inverter input voltage adopted variable voltage control, when the external environment changed, a new dc voltage value will be calculated and after the judgment and comparison a reference voltage will be output, through the coordination and cooperation between the PV power optimizer, the series of PV power optimizer will eventually keep stable in10%of the rated voltage range.The simulation verified the buck-boost mode and the conversion process of the PV power optimizer, compared with the centralized MPPT system, it can save energy loss caused by shadows. The simulation was under different conditions, in the condition of insufficient number of PV modules, it can solve the insufficient high voltage; in the condition of different degree of shadows, the output of dc voltage and PV power optimizer is constantly changing, the final simulation results verified the adaptive voltage controller was effective in voltage boost and stabile.