Research On Integrated Control Of Voltage And Power Factor Based On Electric Spring

Energy saving,emission reduction and green electricity have promoted the rapid development of renewable energy generation.As the main form of renewable energy power generation,DG output power is affected by the intermittent characteristics of renewable energy sources,which is highly volatile and difficult to predict.Therefore,large-scale DG grid connection will cause problems such as voltage fluctuations and PF failure in the distribution network.In order to solve the problem of DG grid-connected voltage and improve the capacity of DG in distribution network for,the traditional control technologies of voltage,PF and ES have been widely concerned by scholars at home and abroad.However,with the popularization of renewable energy generation and grid connection,traditional control technologies of voltage and PF wasn't been able to solve the problem comprehensively and effectively,while voltage and PF stabilization technologies that rely on load switch control are less flexible and cannot be continuously controlled.Therefore,in order to solve the above problems,improve the capacity of the distribution network to the grid-connected DG,and the stable operation of the power grid,this paper proposes the control methods of ES-based voltage and PF based on ES theory.The main contents are as follows.Firstly,the voltage control technology of ES is studied.After introducing the basic concepts of ES,the circuit model of ES is established.What's more,the four circuit topologies of ES and their effective operating ranges are compared herein.And as the research object,the ES-B2 B topology is selected in this paper.By analyzing the advantages and disadvantages of the ES control circuit,an adaptive PI control method for ES is proposed,and the effectiveness of the method is verified by simulation.Secondly,the control technology of ES in PF is studied.Establish ES power control model,including active control model and reactive power control model.Than analyze ES output voltage and input current control model.Combined with ES power control model,an ES-based reactive current closed-loop control method is proposed for PF control,and the effectiveness of the method is verified by simulation.Thirdly,the integrated control of voltage and power factor of ES is studied.The traditional ES control method based on the Radial-Chordal Decomposition principle is analyzed,and its disadvantages in voltage and power factor control are obtained.Then,based on the above ES power control model,a four-quadrant control model of ES is established.Based on the four-quadrant model,an active-reactive voltage and power factor control method based on ES is proposed.The validity of the control method is verified by simulation.Finally,the application of ES in power systems is studied.This paper mainly studies the application of ESs in household photovoltaic systems,and uses its active power control to achieve power fluctuation suppression of household photovoltaic power generation systems.Principle analysis and experimental simulation verification are performed respectively.Through the research in this paper,it is proved that ES can flexibly control the power flow in the power system,effectively Improving the power supply quality of household photovoltaic systems.