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Research On Power Sharing Strategy For Paralleled Virtual Synchronous Generators

Posted on:2019-12-02Degree:MasterType:Thesis
Country:ChinaCandidate:Y ZhangFull Text:PDF
GTID:2382330566998241Subject:Electrical engineering
Abstract/Summary:PDF Full Text Request
The large-scale use of renewable distributed generation has provided new ideas for solving the energy crisis and environment damage.The distributed generation has advantages in terms of reducing environment pollutants,making full use of renewable energy,reducing construction period and realizing economic benefits.And it helps to increase resource utilization efficiency,optimize the energy structure to maintain the sustainable energy development.Parallel inverters system can expand capacity,improve the reliability and achieve redundancy in power supply system.Virtual synchronous generator(VSG)control can simulate the inertia and damping characteristics of the real synchronous generator in power system.VSG control has the ability to improve robustness on frequency disturbance and adjust the voltage of the power system.In this paper,the power sharing strategy of paralleled VSGs is studied in detail.Firstly,the basic principle of VSG control is described in detail.Virtual excitation controller and speed controller are designed based on the synchronous generator model.The influence of key parameters on power and frequency response characteristics of VSG is discussed.On this basis,the interaction between parameters of paralleled VSG is analyzed.And the influence of parameters on the stability of the system is also discussed.Secondly,the effectiveness of VSG can be significantly affected by resistive line impedance.It will cause power coupling between the active and reactive.This parper analyses the impact of paralleled VSG equivalent output impedance on power coupling.To reduce the influence of the power coupling,a virtual impedance control strategy based on the VSG stator equation is proposed.The strategy can improve performance of the system.Finally,the parameter matching method for power sharing is proposed in this paper.The influence of line impedance on the precision of reactive power sharing is analyzed.The reactive power sharing accuracy is increased by improved reactive power drooping control strategy.The effectiveness of the proposed active power sharing method is demonstrated by simulation results with the software Plecs.
Keywords/Search Tags:Distributed generation, Paralleled inverters, Virtual synchronous generator, Power sharing strategy
PDF Full Text Request
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