Single-stage multi-input Buck grid-connected inverter

Single new energy power supply has many defects, such as strong intermittency and poor power quality, In order to make full use of new energy and improve power supply quality, it is necessary to combine multiple new energy power generation devices to supply power together. In order to overcome the shortcomings of single new energy power supply and improve the stability and flexibility of the power supply system, it is urgent to explore and seek a multiple input grid-connected inverter with a single-stage topology. A single-stage multi-input Buck grid-connected inverter is proposed and studied in this paper. The system’s circuit topology, control strategy and derivation of multiple duty cycles are researched thoroughly. This system is composed of multiple input sources and their corresponding filter capacitors, parallel time-division selection switches, full bridge high-frequency inverter, power frequency transformer T with primary side leakage inductance and output filtering circuit. In the energy management control strategy, the outer loop uses MPPT, and the inner loop uses decomposed filtered inductance current. A 1kW experimental prototype is designed, and the experimental results are feasible, proving the system can be applied in practice.