| In hybrid renewable energy power systems, it is effective to simply the system structure,decrease the size of converter, keep the cost of system down, if the multiple dc-dc converters arereplaced by a multiple-input converter(MIC). MIC power systems are typical multi-input multi-outputcoupling systems, when the input sources supply the power simultaneously, and it has severaloperating modes. Control design is difficult for a MIC to achieve good control performance becausethere are various modes of operation. This paper elaborates the design of two loops according to asingle primary winding dual-input buck converter and design the current and the voltage controllers inthree operating modes.In the thesis, the operating modes of the SPW dual-input buck converter are proposed. Then theeffect of relative chronology of the switches of the PVSCs and the mother converter on the outputinductor current ripple are analyzed, and the control principles of different modes of the converter areelaborated to analyse multi-mode transition.A detailed approach is provided utilizing state-space averaging method to obtain the small-signalmodel of the converter and the transfer function matrix from control to output, then a decouplingnetwork is added to allow seperate controller designs. The steps of close-loop designing to guaranteethe control performance of all three modes of operation.An500W prototype has been built and tested in the lab. Design of main circuit, drive circuit andcontrol circuit are completed, and simulation circuit also has been built. Simulation and experimentresults verify the control design. |
