Load Modeling With Generalized Load And Technology Support System

Power system simulation is the basis of power system planning,dispatching and control.The accuracy of power load model directly affects the simulation results of power system.With the large-scale development of power grid,the continuous deepening of the process of smart power grid and the large number of grid connection of distributed generation,the time variability,dispersion and uncertainty of power load become increasingly prominent,and it is difficult for traditional load model structure and modeling methods to accurately describe the load characteristics.This paper mainly studies the technical support system of generalized load modeling including pumped storage power station,the specific contents are as follows:(1)In order to solve the problem of load modeling after grid connection of variable speed pumped storage power station,based on in-depth analysis of the operating principle and internal structure of variable speed pumped storage station,a generalized load modeling method for variable-speed pumped storage power station is proposed.The operation mechanism of variable-speed generator-motors in pumped storage power station was studied,and their dynamic characteristics were analyzed in depth,and a generalized load model with variable-speed generator-motors of variable-speed pumped storage power station was constructed;a simulation system was built to study its influence on power system stability,verify the effectiveness of the proposed method.(2)In order to solve the shortcomings of the traditional AIMM load modeling algorithm due to the use of fixed Markov transfer probability,a method of adaptive adjustment of Markov transition probability is proposed.The update weight of the load model at a certain moment and the weight of the previous moment are known.The difference between the two reflects the change in the degree of matching between the model and the actual situation,and the difference is used to adjust the transition probability between the models.An algorithm for adaptive adjustment of Markov transition probability is established.The algorithm realizes the adaptive adjustment of the transition probability matrix and meets the two basic conditions of the elements of the Markov transition matrix;AIMM load modeling based on Markov transition probability self-adaption and AIMM-based load modeling are compared and analyzed,and the effectiveness of the proposed method is verified by simulation.(3)In view of the shortcomings of the current load modeling system software,a new type of load modeling technology support system was developed.The system is based on the combination of B/S and C/S,using Visual Studio 2013 as a development tool,using C#and C++as programming languages,and using MFC,database communication technology,and ASP.NET web development technology for system development,and according to the system architecture and function design,the functions of the management of the background load model database and load modeling using modeling methods(component-based method,measurement-based method,improved AIMM algorithm)are realized respectively.Through practical application,it is proved that the load modeling technology support system built in this paper has the characteristics of advanced technology,powerful functions,good man-machine interface,and simple operation,which promotes the practical process of load modeling.