Research On Load Modeling Theory And Development Of Load Modeling Platform

With the scale of power grid expanding and regional power grid interconnection, establishing an accurate load model is a critical problem in power system modeling. In recent years, a lot of load modeling research work was carried out, that has significant meaning in power system digital simulation and dynamic security analysis. The power load has the characteristics of randomness, dispersion and discontinuity, which increases the difficulty of the power system load modeling. Therefore, the research of load modeling method has important theoretical value and practical significance. In this paper, load modeling theory and load modeling system are deeply studied.Based on the randomness of load composition and the time-varying of load characteristics, the restriction factors of accurate load modeling are analyzed thoroughly. The load modeling based on analytic hierarchy process (AHP) is proposed in this paper. Electric traction load has characteristics of randomness and volatility. While synthesis load model considers impact of power distribution network and compensation capacitor. Single load model cannot describe power load accurately and effectively. Advantages of two kinds of load models are combined with. To analyze qualitative problems quantitatively, internal connections and differences of these two models are used as criteria of AHP. Active power fitting degree, reactive power fitting degree, environmental impact and model reliability are formed in the criterion hierarchy. Weight coefficients of these two models can be calculated, after different criteria hierarchies are formed by analyzing internal connections and differences. Distribution network and traction power system synthesis load model will establish after synthesizing these two load models by weight coefficients. This method can adjust the weight coefficients with the change of power load, so the randomness problem of power load can be solved. The effectiveness of the proposed method was examined through simulation. MATLAB is used to simulate actual power system, parameter identification results and power fitting curves of synthesis load model and traction power system load model can be calculated by simulation data of different load models. Parameter identification results and power fitting curves of distribution network and traction power system synthesis load model can be calculated, after weight coefficients of these two models integrate. Parameter identification results by measurement-based modeling approach and power fitting curves show that load modeling based on AHP can effectively improve the accuracy of load model.In this paper, a load modeling platform based on AHP is developed. The platform uses MATLAB GUI as a front desk operation interface, the ODBC database programming technology is used to connect MATLAB and database. After compile and test this platform, it has achieved functions of database view, typical load modeling and load modeling based on AHP. Load modeling platform based on AHP achieve to identify the classic load model (CLM), the synthesis load model (SLM), the generalized load model (GLM) and traction power system load model (TM) completely and comprehensively, and accomplishes the load modeling based on AHP. Compared with existing load modeling platforms, this platform contains a lot of load models and identification algorithms, the function of parameter identification and fitting curves of load model have a great enhance. In this paper, Load modeling platform based on AHP has the advantages of fully functions, friendly interface, stably operation and well extensibility.