Research On Full-bridge Boost Multiple-input DC-DC Converter Mode Grid-connected Inverter

With the development of human society, renewable energy as an alternative to traditionalfossil energy sources to solve the energy crisis and environmental pollution problems havereceived increasing attention. Grid-connected inverter as the key technologies and thetechnology of joint supply power by multiple renewable energy become an important researchdirection.Based on the detailed discussion on the research actuality and development of multi-inputDC-DC converter and grid-connected inverter, the full-bridge Boost multi-input DC-DCconverter mode grid-connected inverter is proposed and deeply study in this paper. Thisconverter is cascaded by full-bridge Boost mode DC-DC converter and full-bridgegrid-connected inverter. The control strategy of master-slave instantaneous voltage and currentphase-shifted is adopted by the former, and the control strategy of instantaneous voltagefeed-forward, current feedback unipolar SPWM is adopted by the latter.The circuit topology of full-bridge Boost multi-input DC-DC converter modegrid-connected inverter, control strategy, the characteristic of steady principle, working mode aredeeply investigated in this paper. The important conclusions and the design of criteria of keycircuit parameters are obtained.The theoretical analysis of full-bridge Boost mode two-input DC-DC converter have shownthat the converter has the advantages such as multiple input sources can supply the powersimultaneously or individually, double isolation among multiple input sources and between inputand output of the converter, simply topology, high power density, small input current ripple etc.The theoretical analysis and simulation result of6kW430VDC/220VAC full-bridgegrid-connected inverter indicate that the inverter has the advantages of better dynamic and staticperformance, high quality of output current waveform, simple circuit structure, high conversionefficiency, low cost. Principle tests confirmed the correctness and feasibility of the converter andlay the technical foundation on joint supply power of variety of renewable energy.