Improvement of transient stability performance of VSG considering power angle stability and fault current limiting
In addition to transient power angle instability,the virtual synchronous generator system may also experience overcurrent in the event of a grid short circuit fault.In order to improve the transient pow-er angle stability and fault current limiting performance of VSG,firstly,the overall control structure of virtual synchronous generator system including voltage and current control loop,virtual impedance and power control loop structure is established in this paper,the theoretical basis for establishing a virtual im-pedance power model is provided.Due to the activation of reactive power control loop,transient power angle stability will be reduced,a method of improving the power angle curve by setting the free control branch of the voltage increment is proposed.Secondly,with the combined effect of the reactive power control loop and the voltage increment free control branch,a virtual impedance optimisation method that can simultaneously satisfy transient power angle stability and fault current limitation is proposed for two different operating conditions,namely"without considering fault removal"and"considering fault remov-al".Finally,adaptive control algorithms for transient power angle instability control and fault current limi-tation of virtual synchronous generators are proposed to meet the requirements of real operating condi-tions.The validity and feasibility of the control strategy proposed in this paper are verified by the simula-tion model.
virtual synchronous generatorsynchronous stabilityequal area rulevirtual impedancefault current limitationLyapunov stability
万方数据
维普
