Research On Modeling And Fault Diagnosis Of Power Grid Energy Storage System Based On Switching System

With the increase of national industrialization degree,the load fluctuation of power grid increases gradually,and the loss of power grid in the platform area is increasing.In order to further reduce the transmission loss of power grid and improve the operation efficiency,the energy storage system of power grid in the platform area with supercapacitor as the energy storage carrier is becoming more and more mature.There are a lot of power electronic circuits in supercapacitor energy storage system.As the control circuit of the energy storage system,the power electronic circuit has a high failure rate and serious consequences.If the fault cannot be diagnosed quickly,the energy storage system will fail or even be damaged.Therefore,it is particularly important to carry out the modeling and fault diagnosis research of the grid supercapacitor energy storage system in the station area.First of all,based on the switching system theory,this paper establishes the switching model of the supercapacitor energy storage system in the station area,and according to the Lyapunov second method,an appropriate switching law is designed in this paper to control the charging and discharging working states of the energy storage system,so as to achieve the purpose of charging the energy storage system when the load power is low and discharging the energy storage system when the load power is high.Then,based on the mathematical model method,the fault diagnosis of power electronic circuit is studied.Starting from the basic physical characteristics of power electronic circuits,the use of power electronic circuit switching system model,is proposed in this paper by comparing the expectations of circuit switching rule and the actual switching rule for fault diagnosis of power electronic circuit fault diagnosis methods,this method has characteristics of easy implementation,high universality,diagnosis rapidly.In addition,this paper studies and summarizes the acquisition of circuit expectation switching rules involved in fault diagnosis and the topology identification of actual circuits,and proposes a topology identification method based on the numerical characteristics of state variables and voltage monitoring.Finally,this fault diagnosis method is applied to the energy storage system of power grid in the platform area,so as to realize real-time monitoring of the working status of the energy storage system,so that it can locate the fault point and fault type after the failure,and send out alarm information.And MATLAB simulation platform is used to verify the correctness of the switching model of the supercapacitor energy storage system in the station area and the effectiveness and accuracy of the fault diagnosis method.