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Voltage And Reactive Power Control In Substation Under Decentralized Control Mode Of AVC

Posted on:2011-03-31Degree:MasterType:Thesis
Country:ChinaCandidate:A J MaFull Text:PDF
GTID:2132360308958588Subject:Electrical engineering
Abstract/Summary:PDF Full Text Request
Voltage quality has a major impact on the stability of power grid and safe operation of electrical equipment, so it is an important indicator of power quality. In recent years, automatic voltage control (AVC) has been widely researched and applied at home and abroad in the regional power grid, and it has achieved the desired results In the optimization of voltage quality, improving system safety, reducing loss, and reducing labor intensity dispatcher.Voltage and reactive power control (VQC) in substations is an important component of automatic voltage control (AVC).This article divided control voltage and reactive power control in substations into local mode and the decentralized control mode and centralized control mode under automatic voltage control (AVC) system, and introduces a variety of control modes Research. Under the decentralized control of mode Automatic Voltage Control in Power (AVC) system, designed the hardware architecture map of the substation part in the AVC system and the block diagram of voltage and reactive power control system.Against the dynamic optimization control module of the system, at the base of forecast data, this paper construct the mathematical model of reactive power/voltage control in substations that make the voltage and reactive power in the secondary side of transformer closest to the expected value, and the number of movements about tap and capacitor as little as possible, and use immune-ant colony algorithm to seek the optimal control strategy of this model. The calculation of example indicates that the tactic by immune-ant colony algorithm has a best accuracy.Against the static optimization control module of the system, because the defects that traditional VQC strategies are not adapted to AVC and their control effects are unsatisfied, in this paper a new VQC strategy for substation is proposed. According to this strategy and based on desired voltage value of AVC, adjusting times of on-load tap changer (OLTC) and switching times of capacitor banks, a multi-objective decision-making model is constructed. For the selectable schemes to solve the proposed model an objective decision matrix is built and through non-dimension treatment the objective decision matrix is changed into relative superior attribute degree matrix of all objectives. To overcome the shortcoming of single weight determination and make the determination of weight more effective and reasonable, the improved analytical hierarchy process (AHP), i.e., the subjective weight determining, and dispersion maximization, i.e., the objective weight determining, are integratively utilized to determine the weight the weights of indices. Finally, the optimal control strategy is solved by multi-objective decision-making based linear weighted sum. The feasibility and superiority of the proposed control strategy are verified by calculation example.
Keywords/Search Tags:Automatic voltage control (AVC), voltage and reactive power control (VQC), immune-ant colony algorithm, multi-objective decision-making, combination weighing
PDF Full Text Request
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