Improved 1kW solar inverter with wide input voltage range

Abstract

In case of medium voltage (several tenth up to several hundred volts) solar inverter applications of DC-DC converter for voltage level adaptation is required. To raise the over all efficiency of the inverter a spited power stage concept was chosen. The insertion of a further optimization topic leads to a significant improve of the system efficiency. In our model two coupled converter stages are used. Therefore, due to the usage of synergy effects only two additional power electronic components (a diode and a power switch) are necessary for the system extension. In the current paper the development of a 120V-240V DC (input) to 230V AC(output)/1 kW inverter is derived, realization hints are given and the efficiency of the complete converter is compared to a conventional solution. Further optimization aspects and improvements are discussed.