Research On Weak Area Recognition Method For Voltage Stability In Power System Based On Fuzzy Clustering

Since 1970's, system disintegration accidents caused by voltage instability have occurred many times in some big electric power systems overseas, which have caused long time large area power cut and huge economic loss. The system voltage collapses are often caused by voltage instability of some bus or some area, then proliferate to the overall system, make the system disintegrate. Therefore how to judge the system voltage stability weak nodes and weak area has become a focus problem.With data mining technology in the electric power system of more extensive, clustering algorithm as a supplementary analysis, a system also used in a wide range of state determined that the power load forecasting, system fault analysis, users load classification, dynamic load characteristics Clustering, and many other areas.This thesis aims to propose some practical voltage stability weak area indices, and carry on thorough analysis to the voltage stability weak area. First through the calculation of system loss sensitivity,dV/dQ and voltage sensitivity, and so on, through the establishment of data processing fuzzy clustering sample space and then using fuzzy clustering algorithm to calculate areas of different cluster radius, by clustering the best way to assess effectiveness of cluster radius, in accordance with the voltage stability were weak areas; Finally, use the result of weak area as operation reference for power system.Based on the IEEE 39 node system and the a real Power Grid Simulation tests .Loss sensitivity, dV/dQ, voltage sensitivity, modal analysis, as well as fuzzy clustering method weak nodes were calculated and compared area, comparative analysis showed that Fuzzy clustering methods for the analysis of the data through clustering, can make up a single calculation error sensitivity of the indicators, compared with modal analysis of the real-time speed with good characteristics.Finally, the method of fuzzy clustering node voltage stability weak area is approached to the application of the results of IEEE39 bus system and a real power grids, in the voltage collapse under the conditions of operation before the collapse of the weak points judgement area emergency load-shedding, and not its weak areaal judge for the entire network of direct shear load levels compared. The results showed that the area power grid to identify weaknesses in emergency situations to guide operation to make an accurate judgement of staff to the smallest possible cost recovery system stability. Verification of the fuzzy clustering method proposed in this paper the validity and accuracy of the power system voltage stability weak points, the weak area analyses provide a good practical tools.