Study On Reactive Power Optimizing For Distribution Network

The reactive power compensation is an important problem of electric power system's economical operation. This paper presents a new algorithm on reactive power optimization so that the power factor of user and network is improved, the user's voltage quality is improved, and the transmission ability of transformers and lines is increased. Steps of study are following.The first step is power flow calculation. The node voltage and distribution of power are obtained under a determined operation condition, so as to check whether distribution of power flow is reasonable, whether quality of node voltage is satisfactory, whether every element is overloaded, and power losses etc. Node correlation matrix is defined again and a method of building node correlation matrix is present. The precise power flow calculation is realized on the basis of node correlation matrix. The energy loss calculation and reactive power optimization are based on the power flow calculation.The second step is theoretical calculation of energy losses. The energy loss is defined that sum of every element power loss under a given time. From this point, the precise energy loss is very complicate. Method of energy losses' calculation should be simplified according to different requirement and condition. By the node equivalent power method, energy losses is transformed into power losses on the basis of node correlation matrix, which original data are very easily collected and arranged, which original data are more precise from power meter than that from current meter.The third step is reactive power optimization. It includes compensation capacity, distribution of capacity, location of compensation and the economic power factor etc. Distributive compensation is applied to distribution network so that the reactive power is balanced in user's place. The equivalent tiny ratio of network losses is derived from calculation of power flow and power losses, instead of traditional method that the equivalent tiny ratio of network losses is derived from impedance matrix parameter of lines and transformers. Making a group of equations that is formed according to the principle of the optimum tiny ratio of network losses, the result of reactive power optimization is obtained, replace of trying compensation method by given power factor and power flow, again and again.