The Research Of EMC In Solar Photovoltaic Grid-connected Power System

The traditional energy and air pollution are more urgent in our life,improving the structure of renewable energy and enhancing the power quality have been the Strategic measures of our state.In Recent years,the solar energy was concerned for its pollution-free,resource-rich and short construction cycle with the development of power electronics and the support of national policies.The electromagnetic problems become important for the using of nonlinear power electronic devices in solar photovoltaic grid-connected power system,even more important with the increase of grid-connected system.In this paper,the main interference,coupled channel and sensitive equipment was analyzed on the base of 6KVA Three-phase grid connected inverter system.The electromagnetic compatibility of the inverter system has been analyzed and designed in detail;the following aspects are included:1) Common and differential mode EMI filter were designed for the system;2) Anti-interfere on the hardware circuit and soft system were designed;the feature of PCB and the basic rules of PCB were analyzed;circuit grounding,the shell structure and electromagnetic shielding were designed for the system;and over-voltage protection design is also included;3) The further analysis on harmonic generation and suppression were made,in order to have a good suppression of high frequency harmonic,a LCL filter is designed for the system and simulated with Matlab;4) The power dissipation of IGBT increase with the switching frequency increase, so the efficiency of system is affected.In order to enhance the system efficiency, the DSVPWM modulate is analyzed in details and applied in the inverter system. A model is set up in Matlab,the waveform is got from simulation,and the drive waveform is also got from the hardware circuit.The system efficiency increase for the using of DSVPWM modulate model.From the experiments on the inverter system,the anti-interference ability and the stable of the system were improved for the design of electromagnetic compatibility.