Research On Real-Time Economic Operation Of Distribution Network

The economical operation of the distribution network is to reduce the loss of lines and transformers maximumly on the basis of guaranteeing the security of the distribution network and satisfying the power supply. Distribution network reconfiguration is a effective way to reduce the loss of distribution network, and it is also can balance the load and improve the voltage quality. At present, the distribution network reconfiguration mainly operates according to the season. Because load changes at any moment, the reconfiguration effect is not obvious. With the improvement of the automatic level of distribution network and communication technology, it is possible to adjust network structure according to the actual conditions of load. At present, the method solving reconfiguration problem is mostly aim at the static reconfiguration with a given load condition. Usually, the static network reconfiguration applying to the planning field is not competent for the operation problem under continuous time. For this reason, aiming at the active power economical operation of the distribution network, a real-time economical operation scheme based on ultra short-term load forecasting is proposed. The main research works in this paper are as follows: (1) Aiming at the active power economical operation of distribution network, ultra short-term load forecasting is considered in the real-time economic dispatcher of the distribution network, and a new reconfiguration scheme is formed according to the prediction results of next decision period. Benefit of the new reconfiguration scheme is estimated by the controller, and the times of switch movement is considered synthetically, thus the controller can determine whether a configuration should be carried out. This method can reduce power supply cost, decrease the times of switch movement and unnecessary structural adjustment, and then improve systematic economy and stability effectively. (2) The ultra short-term load algorithm is improved and made to be suitable for the real-time economic dispatcher of the distribution network. Instead of 24 hours'load of whole day, the relative load increment of next period is predicted. So the Ann network size can be diminished. The whole day is also divided into several parts and different artificial neural network model is used separately. It avoids a lot of problem such as long study time, unstable and convergence problem of the network. (3) The reconfiguration model based of ultra short-term load forecasting is set up. The movement times of switch and the reconfiguration benefit restrain is considered in this model. The method of making switch movement order is proposed and its necessity is discussed. The method of estimating the benefit of reconfiguration is also proposed.