Research On The Multiport Converter Of Distributed Generation Based On Nine-Switch Converter

Under the background of energy saving and emission reducing, the development and utilization of the new energy has got more and more attention, the distributed power generation has received more and more attention and application because of low investment, clean energy, high reliability and flexibility. The converter of distributed generation based on the power electronic technology is very meaningful to the development and utilization of new energy, this paper did the following research of nine-switch converter based on this theme:Firstly, this paper expounded the research background and significance of the research, and then introduced the topological structure and control method of the frequently-used converters of distributed generation.Subsequently, this paper introduced the topological structure of nine-switch converter and the applications of this converter. Combining with the topological structure of nine-switch converter, this paper did the research of the switch signal modulation method based on SPWM and the algorithm of modified proportion resonant (PR) controller which is used to control the output current of the converter.The function of the output ports of nine-switch converter has been set, the up port was set as three-phase inverter and the down port was set as the active power filter (APF), the simulation models of the two parts were set respectively, during which process, the design procedures of the filter installed in output port was introduced, the method of using PR controller to compensate harmonic wave of different frequency in APF was introduced, and then combined the two different model into the model of nine-switch converter, by the way of adding DC bias to the modulating signal to give the model the function of grid-connected inverter and APF.To prove the research contents above, a experimental platform of nine-switch converter has been designed and established in this paper, this platform included two parts of hardware circuit design and software programmaing design, the part of hardware circuit include the sampling circuit, the main control circuit, and the driving circuit, the part of software include the main program of DSP, the program of FPGA and the interrupt service routine (ISR) of DSP, especially the AD interrupt service routine, and the experimental waveforms would be given, the experimental results were also analyzed.Finally the paper made the summary and the outlook of the research.