Transient Voltage Stability Of Grid-connected Photovoltaic Power Generation Based On Power Storage System

In recent years,with the significant increase in the proportion of wind power photovoltaic-based renewable energy generation and the diversified development of the distribution network,the problem of grid voltage stability has become more serious.In order to improve the responsiveness of the power grid to the dynamic process of voltage in an uncertain environment,the energy storage system can be introduced on the renewable energy power generation side to directly or indirectly change the system reactive power support characteristics,so as to improve the system transient voltage stability effect.However,how to effectively use the grid-connected photovoltaic power generation system with energy storage system for transient voltage optimization control,improve transient voltage stability,improve the utilization rate of renewable energy,and ensure the safe and stable operation of the distribution system is a high proportion of renewable energy An important development trend in the research of voltage stability optimization control in distribution systems.Aiming at the difficulties of reactive energy coordination of photovoltaic energy storage systems and the complex characteristics of voltage stability of distribution networks,combined with the traditional theory of transient voltage stability analysis of distribution systems,this paper analyzes the voltage regulation characteristics of photovoltaic energy storage combined systems,high-scale photovoltaic The research on the determination method of the transient voltage stability of the distribution network and the cooperative control strategy of the photovoltaic energy storage combined system to improve the transient voltage stability,the specific contents include:First,study the voltage regulation characteristics of photovoltaic power generation grid-connected systems with storage systems.Based on the modeling of the mechanism and regulation characteristics of reactive power adjustment resources such as photovoltaic power generation systems,batteries and super capacitors,a photovoltaic power generation system model including a hybrid power storage system is established,and a photovoltaic storage based on dynamic reactive power adjustment is proposed Can be combined with system voltage regulation model.Secondly,study the method of judging the transient voltage stability of high-ratio photovoltaic distribution network.Aiming at the problem of judging the voltage stability of complex power distribution systems,the mechanism of transient voltage stability is studied,and the quantitative model of the voltage stability margin evaluation index during the transient process is established.Stability evaluation model,and verified the correctness of the model in simulation examples.Finally,the cooperative control strategy of photovoltaic power storage combined system for improving transient voltage stability is studied.Considering the constraints of transient voltage stability and the constraints of reactive power output characteristics of photovoltaic inverters,the reactive power dynamic output characteristics of photovoltaic storage systems under different transient voltage regulation requirements are studied,and the voltage stability coordination of photovoltaic storage systems is proposed.Control method,and verify the effectiveness of the proposed method in the built simulation model.