Study On Low-voltage Reactive Power Configuration Of Guangdong Power Grid

With the rapid development of power system, the power quality is required to be betterand better, besides the distribution network is the important part which supplies electricalenergy to power users by connecting the power sources or transmission systems and the userfacilities. However, reactive power flow in the distribution networks will cause the power lossand the voltage loss. So Installing adequate capacitors of reactive compensation in networksand selecting optimum compensation to make local reactive power equilibrium, can reducereactive power in distance transmission and make full use of transmitting and transformingcapacity of equipment, and improve the quality of electric energy of power system anddecrease the loss of networks. Through the optimal allocation of reactive power compensation,the lower loss, better voltage quality and higher efficiency can be achieved. In the other hand,differences of distribution networks’ structures and complexity of operation situation makethe optimization of reactive power configuration become complicated nonlinear programmingproblems, which is difficult to achieve large-scale configuration of reactive power planning.Studying on the low-voltage reactive power optimal configuration problem, the purpose ofthis thesis is to find out a kind of reactive power configuration planning method which is easyto implement with theoretical and practical value.In this thesis,10kV feeders’ operation situations of the Guangdong power grid voltageare statistically analyzed and classified. To realize differentiated configuration of reactivepower compensation,10kV distribution feeders are classified into four types according totheir electricity characteristics firstly, and their corresponding base-state models areestablished for reactive power optimization. Several indicators have been defined in order tofacilitate the base-state analysis, such as the configuration rate of reactive powercompensation, the average load rate of distribution transforms on the feeder, the naturalpowerfactor of distribution transforms, the generation-consumption ratio, and the sensitivitybetween characteristic parameters and the configuration rate of reactive power compensation.Secondly, the configuration rate of reactive power compensation of each base-state model hasbeen calculated by reactive power optimization computation and the sensitivity analysis on various electricity characteristic parameters, and then the configuration rate of non-base-statefeeders can be reckoned according to it. At last, the recommended table of the configurationmedian rate about reactive power compensation capacity can be provided and can be used toguide the reactive power configuration planning on different types of10kV feeders anddifferent transformers.In this thesis, the base-states reactive power optimization based differentiatedconfiguration method is proposed. At last, it has been demonstrated by an example that thismethod is effective and practical.