Analysis Of Substation Voltage Stability And Regional Power Grid AVC System

With the continuous development of society and improvement of living standards,the demand of power boosts as the same time as large-medium cities gradually expand,the security and stability of power grid system become the key of the power industry.Voltage is an important parameter in grid operation and one of the important indicators of power system quality.In substation's centralized monitoring and supervising process,the factors of influencing the voltage change is multifaceted.In-depth study of the influencing factors contributes to a better control of voltage stability.In recent years,automatic voltage control(AVC)has gradually become important means to improve the regional power grid and enhance the economic system.AVC usage is directly related to the merits of substation voltage quality.Establishing a sound automatic voltage control system not only does a great help to evaluate substation voltage stability factors but also make much easier for controllers to knew about AVC's impact on current period power gird.Although there are plenty of domestic voltage control literature,the overwhelming majority are research and applications on automatic voltage control system theory.For a single substation,the automatic voltage control system can not intuitively reflect how much influence this site brings;while for multiple substations,we can not through pural substations' automatic voltage control system usage situation to compare advantages and disadvantages of them.In foreign countries,due to the different regulatory mechanisms and the different infrastructure,the main focus are difference in the study of automatic voltage control system,for example,some of them play emphasis on voltage control theory,the others oriented on secondary device operating data under grid control system,and they lack of analysis and overall evaluation system on the factors that impair the voltage stability.The research is helpful to cognize the factors affecting the substation and voltage stability,evaluate automatic voltage control system actual usage situation on regional power grid and classify the AVC system stability and efficacy act on voltage substation.It also helpful to abstract evaluation criteria and simplify Index System.Mathematics theory are applied to make an overall rating about AVC system which affected by many factors and get clear results.Specific research work is summarized as follows:(1)Summarize and analyze effect factors of substation voltage.Most researches values on the power system's voltage stability at home and abroad.Generally considered,insufficient reactive power is the root cause of voltage instability.For the substation,there are three main ways to disturb reactive voltage: According to the situation,switching shunt capacitors,adjusting transformer taps,controlling load reactive voltage variation law.(2)Establish a regional grid AVC Evaluation System.AVC system brings manifold efficacy to local power grid scheduling system.The condition in affecting efficacy are also multi-faceted.To solve this problem,establishing a regional power grid AVC Evaluation System which each single factors are listed and analyzed in contributes to mastering the actual use of AVC.(3)Apply Fuzzy Evaluation to judge AVC Evaluation System.Factors affecting the AVC system's effect are multiple and they have a certain degree of ambiguity.The combination of Fuzzy Mathematics and AHP Algorithm can successfully solve such problems.