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Research On The Control Of Reactive Power And Voltage Of Distribution Networks Contained Distributed Generation

Posted on:2016-07-08Degree:MasterType:Thesis
Country:ChinaCandidate:Y J FuFull Text:PDF
GTID:2322330473965759Subject:Electrical engineering
Abstract/Summary:PDF Full Text Request
After access of distributed generations(DGs) to distribution network, DGs have impact on reactive power planning in distribution network and reactive/voltage real-time control. IEEE157 standard recommends small DGs access the distribution network, should actively avoid participation in the distribution network voltage regulation. Although IEEE157 standard ensures the safe operation of the distribution network, but to some extent, limit the ability of DGs to provide ancillary services. Therefore, it is necessary to study the reactive power optimization under conditions of DGs.This paper firstly discusses the research status of reactive power optimization in distributed network and studies the model and algorithm of reactive power optimization in distributed network. The main work of this paper includes the following three aspects:Firstly,this paper establishes the model of optimization of a llocation of reactive power compensation device based on Harmony Search Algorithm(HS),which considers the cost of reactive power compensation device and energy loss of distributed network.This paper converts the investment cost of reactive power compensation device into annual value and the objective function is the minimum of annual value and yearly cost of energy loss of distributed network.In order to make the model closer to actual operation of distributed network,the load is divided into maximum load,minimum load and general load,the output of DGs is also divided into the output under maximum load, minimum load and general load.The DGs is as PQ nodes.This paper determines the capacity of reactive power compensation device and the investment cost of reac tive power compensation device and calculates the cost of energy loss of distributed network under maximum load.This paper determines the results of switching capacitor banks and the cost of energy loss of distributed network according to the capacity of r eactive power compensation device.Secondly,this paper establishes the mathematical model of reactive power optimization based on sensitivity analysis, which objective function is the offset of voltage, and consider adjusting the reactive power of DGs and switching capacitor banks for reactive power optimization.This paper analysis the ability of regulating reactive power of DGs and classifies the DGs based on the ability of reactive power compensation.This paper reduces voltage/reactive power sensitivity m atrix and can quickly get voltage / reactive sensitivity matrix to determine the reactive power compensation node by node with high sensitivi ty under the premising of distribution network operating parameters.Lastly,this paper establishes the model of mul ti-objective reactive power compensation based on Pareto optimal and uses the multi-objective Harmony Search algorithm to solve the model directly, without the need to use weights to convert the multiple objectives into single objective.The multi-objective Harmony Search algorithm this paper proposed uses a hierarchical sorting method to find Pareto optimal solution with the help of the adaptive parameters.This paper uses ZDT1,ZDT2,ZDT3 functions to test the multi-objective Harmony Search algorithm and uses the crowding distance and dispersion to evaluate the algorithm,and compares with NSGA-?.The results shows the effectiveness of the algorithm.
Keywords/Search Tags:Distribution network, Reactive power optimization, Voltage/reactive power sensitivity, Harmony search, Pareto optimal
PDF Full Text Request
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