| With the rapid development of modern power electronic technology,the market demand for power quality products is increasing,and the reactive power and harmonic phenomena have a great impact on the normal operation of the power grid,resulting in a sharp decline in the quality of power.Reactive power compensation device can effectively compensate power loss and improve power factor.Static var generator(SVG)possesses the characteristics of quick response,high stability,strong adaptability and small volume,which are the crucial trend to improve power quality.The cost of high voltage SVG is relatively higher.Therefore,Direct R & D of entities lead s to cost wastes and are not practical as well.While entities are running,power module can be regulated only according to experience and theoretical model.For this reason,there is a great need to establish the emulated platform,to assess the potential problems in operation overall and to adjust correctly,by which the stability,reliability and availability of the platform can be achieved and the constant voltage,constant current and reactive power compensation of whole system emulation can be implemented.According to the performance requirements of ±100MVAR,this paper has determined the linking methods.It has designed the simulation platform of H bridge cascade SVG consisting of the main SVG modules to achieve the simulation verification of control modulation strategy and capacitance selection and has proposed the scheme of reactive compensation,which has already been applied practically.The analysis of the results of power quality indicates that the problems of reactive compensation in the power grid of high voltage and high load have been solved and the performance requirements of energy saving have been met.In this paper,firstly according to the performance comparison between "? " and "Y",it is concluded that "? " can better improve the stability and reliability of h-bridge cascade by the mathematical model.Secondly,The simulation platform is established by Matlab to realize the three main modules of SVG C urrent detection and reference current generation?feedforward decoupling control and DC side voltage balance control module.Thirdly,the simulation research of control strategy is the main simulation function,and three-phase phase control method is used to build the overall control block diagram.It has been analyzed constant voltage,constant current and reactive power compensation simulation waveform,which has been verified that the target parameter used as the original parameter is input to adjust the voltage and current to ensure constant voltage equalization and to make the reactive compensation of the whole machine stable;The carrier phase shift modulation technique determines the harmonic content of the voltage and the magnitude of the operating power of the entire device.In this paper,two simulation models of cascade modules have been built,simulation of unipolardual-frequency CPS-SPWM with modulated wave inversion is carried out and by analyzing the port voltage and the corresponding voltage harmonic spectrum,validity and correctness of the single-stage frequency modulation with modulated wave inversion in the H-bridge cascade SVG system application can be verified.Finally,as for the device size selection,the simulation analysis of capacitance has been mainly carried out.According to the simulation analysis of capacitance,the capacity of the whole SVG machine can be determined.Finally,combined with the simulation results,a hardware platform of 35KV±100MVAR static reactive power generator device is built.Through analyzing and comparing the measured waveform,effectiveness of the simulation platform has been verified,the reactive power compensation has been achieved and the performance requirements have been met. |
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