Optimal Placement Of Capacitors In Distribution Network Based On Evaluation Model

Capacitors are employed as main devices for reactive power compensation in distribution network, and the reasonable configuration of capacitors arrangement is of great significance for secure and economical operation of distribution network, since it may effectively improve the voltage level, reduce operation loss, enhance the utilization ratio of transmission equipment and strengthen the adjustment ability of controlling devices. As for distribution network that has been already equipped with certain amount of capacitors for compensation, it is necessary to reasonably evaluate the formal functional state of network under the performance of primary arrangement of capacitors, which may serve as guidance for further optimal arrangement of capacitors. This thesis presents an overall review over the current research situation of the field of capacitor optimal configuration, base on which the researching on optimal arrangement of capacitors in distribution network is carried out, and the main work of this thesis can be generalized as follow:At first, this thesis conducts deeply analysis on relationship between capacitor arrangement and major indices of distribution network, such as transmission line loss rate, voltage level. And the thesis comes to a conclusion that difference in capacity, location and type has remarkable influence on those system indices, while calculation methods for measuring such influence are also presented. Then based on the above information and methods, the model for evaluating reactive power compensation in distribution network is established, which may access the reasonability of the former configuration of capacitor arrangement, while the access result can be demonstrated in the form of sets of removed nodes and added nodes.Secondly, based on the proposed evaluation model, a new optimal capacitor arrangement model is established in this thesis. The main process of solving the new model is as follow: firstly it makes full use of the result of the evaluation model. And in forming the objective function, two particular factors are considered; one is the impact of the recruitment of the formally removed capacitors, while the other is the influence of avenue beneficial rate of investment in installation of new capacitors. Finally, a improved GA method is employed to solve the problem of optimal arrangement of the capacitors.At last of the thesis, a simulation about reactive power compensating evaluation is carried out on a 22-nodes power system, in consequence, the optimization of capacitor placement is conducted by improved GA, the result of which verifies the validity and practicability of the proposed method in optimizing the arrangement of capacitors in distribution network.