Yunnan Power Grid Load Characteristics Analysis And Load Modeling Study

The effect of load model on the power system operation, analysis and control is very remarkable, and its modeling has already been given rise to the electrodynamics engineers and technicians extensive value at home and abroad. Excessive crude load model has been the key factor of restricting power grid simulation calculation precision, thereby establishing the right synthetical load model is significant in engineering. Study on load characteristics of Yunnan Power Grid (YPG) not only can improve the stability of YPG, increase region load factor of YPG, but also has great significance for the low-frequency oscillation since YPG connects with Southern China Power Grid. Developing load characteristics synthesis and load modeling research in YPG can supply effectual foundation to adjust the load parameter and plan reasonable mode of operation. The research process, method and conclusion of this paper have a vast guidance and reference for YPG simulation calculation.This paper selects YPG as main research object, and analyzes several key problems consisted in developing load characteristics synthesis and load modeling research in YPG deeply. The following issues are investigated:(1) Electric power source and load characteristics current situation of YPG are analyzed. Development trend and intending level of YPG load characteristics are forecasted, and its influence factors are also discussed.(2) According to daily load curve of YPG various substations and on the basis of analyzing typical load characteristics, industrial, agricultural, commercial and civil load composition curves were established. The method of analyzing YPG load composition proportion based-on the daily load curve was discussed.(3) It discoursed on the necessity and feasibility of the load characteristics classification and synthesis and clarified the principle and steps of fuzzy clustering. The composition proportion of substations, daily load factor and minimum daily load factor were chosen as the classifying eigenvector, and then the aggregate load characteristics of substations using two classification approaches based-on fuzzy equivalent relation clustering and the fuzzy C means clustering were researched. It arranged 48 110kV power substations of Kunming Power Grid under categories using two methods above and gained the effective classification, in the meantime the corresponding clustering center was calculated.(4) It summarized present situation of application of both load model and parameters for stability analysis in China. According to the clustering result of substations, using model vector base, the model parameter database can be constructed. Using model vector base to construct the model parameter database that YPG simulation needs is maneuverable under current conditions.(5) Fault simulation was used to research transient stability of YPG under different load models and parameters. Focusing on transient stability, the influence of static load model, induction motor load model and proportion of induction motor in total load was studied. The more field measurements and system test data are needed whether stability calculation in YPG should use the whole static load model. If using the static load model simulates load, it should consider the influence of frequency. From the nature of inductor motor, IEEE-6 type is the civil and industrial composite inductor motor, and its parameters have universal representativeness. Simultaneously it also fits the specific load types of YPG whose main load are the industrial and civil load.