Single-Stage Multi-Input Boost Inverter with High Frequency Link

The single-stage multi-input high-frequency-link grid-connected inverter are proposed and deeply investigated. The inverter is divided into three parts: a current source inverter unit, a transformer operating at high frequencies with multiple winding inputs and single winding outputs, and a cycle-converter. The current source inverter unit can contain multiple current source input links, and the boost inductor is connected in parallel with a bypass switch. The corresponding maximum power output energy management strategy of the inverter is proposed, and the magnetic saturation problem of the current source inverter is solved by calculating the energy-releasing duty cycle in real time. This article uses a simple circuit structure to achieve single-stage power conversion and high-frequency current isolation, and has good grid connected waveform quality. The soft switching process of the converter, duty cycle calculation formula and the design of the main circuit parameters are obtained. A 1.5kW experimental prototype of high-frequency-link inverter with two inputs is built and tested, verifying the feasibility of circuit topology and the effectiveness of the control strategy.