| Power factor is an important measure of power quality,and the size of reactive power directly determines the power factor.Compared with the traditional reactive power compensation device,the three-phase H-bridge static var generator(SVG)is adopted in this paper to achieve fast continuous tracking compensation of reactive power,to improve the power factor and improve the power quality.Firstly,the research significance of the subject is clarified,the basic principle of reactive power compensation technology is elaborated,and the existing three main circuit topology and current control strategy are analyzed and summarized.Secondly,the main circuit based on the three-phase H-bridge SVG device is designed,and the parameters of IGBT,DC-side capacitor C,connection reactance L and Hall sensor are designed and selected according to the circuit structure.By building mathematical modeling,the control strategy of the outer DC voltage on the top DC side and the inner control strategy of the current direct control are designed.the underlying PWM control strategy and the on-wave current limiting control strategy for IGBT current are proposed.in peripheral circuit design aspects,current and voltage sampling circuit,IGBT driver circuit,power supply circuit are designed.in Program design aspects,the part program of the DSP+FPGA are designed.Then,the model building of the three-phase H-bridge SVG device based on PSCAD / EMTDC is carried out,which lays the foundation for the next simulation work.Completed the design of the main circuit of the 3D assembly structure diagram,the actual installation of the follow-up prototype practical guidance.Finally,a low-power experimental circuit was set up in the laboratory,and experiments on digital output function of PWM and over-current protection based on FPGA were carried out.The experimental results were recorded and analyzed Which lays a solid foundation for the follow-up of other unfinished experiments... |
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