Power System Load Modeling And Impact Analysis Based On Intelligent Distribution Network

Electrical load is an important part of the power system, it plays an important role in power system operation control, analysis and design. The accuracy of the load model in power system studies affect the scheduling operation of the grid and grid planning and decision realized by the model simulation. At present, the load model and its impact on the smart grid got a great attention of scholars.Building strong and smart grid is the future development trend of the grid, smart grid development is inseparable from the application of electric vehicles, along with the continuous development of electric vehicle charging and discharging technology, electric vehicles will be increasingly used in people’s lives of them. When EV and the electric vehicle charging and discharging station construction of large-scale, the electric vehicle load will be very large, which would make impact on the power load to a certain extent. In order to ensure the power grid could meet the needs of the development of electric vehicles at the same time electric vehicles to avoid make adverse impact on the operation of the grid, we need to study the influence of large-scale application to electric vehicles on the grid.Therefore, the paper utilize the statistical synthesis method establishing the power load modeling, using cubic spline interpolation function and the measured power flow data to validate the effectiveness of the model and analysing the impact of electric vehicles accessing the intelligent distribution network. The main contents as follows:(1) Introducing the concept of intelligent distribution network and power system load modeling concepts, methods, common model structure and parameter identification methods. Papers use statistical synthesis method establish load modeling, first of all classifying the electricity industry users, selecting the typical user, getting the user’s device parameters through the survey, and finally establish the substation node load model.(2) Through substation monitoring equipment get the voltage and power data to establish the cubic spline interpolation function model, the model curve is the most realistic response to the trend of the measured data points. Thus compared with the previous builted model and verifying the validity of the model.(3) Binding the practical construction of the charging and discharging station of electric vehicle somewhere in Shanxi, depending on the different way of the electric car charging and discharging, leads to the classification of electric vehicle load, called a class of electric vehicle as the base load because of it as the traditional load absorbing the electricity, achieving the electricity charge and discharge process of a class of electric vehicle called the bi-directional load. Charging and discharging of the bi-directional load using V2G technology that can achieve two-way interaction of electric vehicles and grid, electric vehicles are used as a removable distributed storage unit. Analysing the operation condition of the charging and discharging motor achieving V2G function running, combined with the local power grid operating characteristics and analysing the influence of based load and two-way load to the grid load curve. Obtaining the result is that as bi-directional load electric vehicles can achieve peak load shifting.(4) Building operation diagram of grid in PSASP, obtained load model into the load parameters, the first work is comparing the power flow with simulation data and the actual flow data, and verifying the applicability and effectiveness of the model; Calculating the power flow of electric vehicles using the charging and discharging mode, it could make a certain reference value for electricity planning. Achieving the grid line loss analysis and calculation, considering the loss of the grid contained the electric vehicle grid in seasons. Finally, analysing the distribution transformers losses and voltage variations of the grid contained electric car, the result is that electric car joining the grid could increase the copper consumption, while charging during peaking hours, the farther distance away from the transformer, the lower voltage on both sides of it.