Research On The Influence Of Electric Vehicle Charging To Distribution Network And Voltage Disturbance Detection

Development and application of electric cars,more and more social attention,the advantage of energy saving and "emission reduction" is very obvious.Future electric cars large-scale access,will bring significant change to power system planning and operation.The electric cars are applied in eliminating the peak and valley difference both day and night,both can be used as a user and energy storage,smooth load effect,also has the effect of the transmission to the power grid to adjust frequency.But the disturbance of electricity cannot be ignored.Therefore,to study the effect of large-scale electric vehicle access to distribution network,as well as the electric vehicle charging to power quality disturbance,it has important theoretical significance and application value for future large-scale construction planning and operation of electric vehicle charging station and improving the distribution network stability.This dissertation focuses on the voltage sag mechanism and detection method when the electric car access to distribution network,charging stations modeling analysis and simulation verification.First discusses the electric vehicle development scale,the technical characteristics and charging methods,analysis of the electric car battery core parts as power battery,charging intelligent control technology,etc.Through the analysis of the types and characteristics of power batteries,the charging method,the mathematical model of power battery and topological structure of the electric car charger were established.The electric vehicle charging motor driver and its intelligent control technology were analyzed,the grid side converter control system structure was established.Applying Dig SILENT/Power Factory software,electric vehicle battery model and simulation models of charger were established,constant current charging and dc chopper circuit control module,the network side of the inverter control module,which provides the theoretical foundation for electric vehicle charging.The dissertation analyzes the influence of the large-scale electric vehicle access to the distribution power system,through modeling simulation reveals that the charging access and fault cause of voltage sag.For electric car result in the distribution network of power quality disturbance detection problem,based on the Hilbert Huang transform(HHT);The classification of power quality disturbance identification method and time locating method are proposed.Applied Dig SILENT/Power Factory software,the model of electric vehicle and the simulation research the voltage sag and time positioning signal classification and recognition were studied,the results show that a good ability to recognize and accuracy.The study reveals the large-scale electric vehicle charging access and fault cause voltage sag,it provided the technical measures to prevent power grid failure and to improve the distribution network security and stability,based on the Hilbert Huang transform of the voltage sag signal classification recognition and time locating method,it has the characteristics of fast response time,high precision,the distribution network real-time detection of power quality disturbance,and provided a new technical way.