A New Type of Photovoltaic Series Micro Converter

Generally, a centralized photovoltaic power converter is unable to track the maximum power of local module. This results the low output efficiency. Thus, a new series micro converter type is put forward in this paper. The DC bus of micro inverter is in series in this topology structure, and the maximum power of photovoltaic module is tracked by each independent micro-inverter. In this way, the overall efficiency of the system output can be effectively improved. An improved network-side control algorithm is studied, and the quasi-PR control and the repeat control technology is chosen for the control of voltage loop and current loop in this algorithm. The impact of the grid frequency fluctuation can be effectively suppressed, and the accuracy is improved. With MATLAB / Simulink tool, a simulation model of tandem type micro converter and centralized converter were built, and the relevant simulation was progressed. The results indicate that the improved control algorithm can be used to achieve good control effect, compared to series micro-converter, the centralized inverter has more stable output power and higher conversion efficiency.