The Research Of Stability Based On Virtual Synchronous Generator With Adaptive Inertia And Damping Parameter

In recent years,with the rapid development of new energy and microgrid technology,distributed power supply based on inverter interface has been increasingly used in power systems.However,due to the inverter's lack of inertia,the stability of the microgrid system is reduced.In order to make the distributed power equipment operate more stably,foreign experts put forward the virtual synchronous generator(VSG)control technology.Based on the flexible and adjustable control parameters of virtual synchronous generator,this paper studies the adaptive control of the virtual synchronous generator and its stability.First of all,this paper gives the core idea of VSG control and its mathematical expression,based on which a complete set of control structure is established and the model is built in Matlab/Simulink.Then,the influence of the values of inertia parameter and damping parameter on the stability of VSG system and the dynamic characteristics of control system are emphatically analyzed,and the simulation results are used to verify the results.In the following,the paper points out the advantages of the flexible controllability of the virtual synchronous generator compared to the synchronous generator.In particular,the virtual inertia and the damping parameters can have significant impacts on the stability of the VSG.On this basis,how the existing adaptive control strategy improves the static stability of VSG and its limitations are analyzed,and an adaptive control strategy is proposed which jointly adjusts the virtual inertia and damping parameters.This strategy can shorten the transient process to the first quarter period of power oscillation and restrain the oscillation amplitude,which significantly improves the static stability of VSG.The simulation results show the effectiveness of the control strategy.Finally,the paper analyzes the power angle characteristics when the VSG has the current limiting control link,and on this basis studies the stability of the VSG under large disturbance.By using the research method of accelerating area and deceleration area in synchronous generator,the limit cutoff angle of fault occurred was solved.The adaptive control strategy in this case is proposed and the mechanism to improve transient stability is also analyzed.Through the simulation results,the paper verifies the superiority of the proposed control strategy.