The Research On Key Technologies Of Self- Healing Control On Intelligent Distribution Network

With the deepening of the state of EHV and UHV transmission and unified strong smart grid strategy, traditional power transmission, substation, distribution, scheduling and other aspects of the various measurement and control equipment and the corresponding data processing and control technology have been unable to meet the high standards of the smart grid, distribution network is the end of a ring that assigned to the system terminal specific load, the high reliability is the basic premise of to ensure EHV and UHV transmission line of power transmission to the terminal power load. Along with the electric power equipment and appliances of various high-tech applications in use, so the performance requirements of the power load of distribution network. In order to meet the higher demand of power load and reduce the fault losses caused by the impact and, the concept of smart distribution network arises at the historic moment, self-healing is the evaluation of a distribution network intelligent main standard. Based on the analysis of the theory and technology of self-healing, this paper refine of the relevant basic concepts of self-healing control of distribution network.Fault self-healing control in smart distribution network is a discrete optimization problem consists of a large number of feeder, electric power equipment and load, the end result is to seek a group action combination composed of intelligent switch in part of the lines of in the condition of keeping the network structure of the distribution network connectivity and line under normal circumstances, the goal is maximize the recovery of power supply with minimum loss and the least switch. At the same time, improving the work reliability of intelligent control switch is the effective premise of fault self recovery, this paper design the intelligent switch from the aspects of the circuit breaker operation speed and the statistics of operation and digital input and output, communication, finally analyses its feasibility.For the limitation of implicating the traditional heuristic search to realizing self-recovery of distribution network, which is restricted by the regional size of the distribution network, it can’t analyze and process rapidly in the fault diagnosis of large-scale distribution network. This paper introduced an improved minimum spanning tree algorithm, taking the power, load and switches in the regional of distribution network as nodes, and distribution lines between each node as the edge of the distribution network equivalent simplification and assigns a weight to each edge, generate the corresponding tree, and then traversal the tree under the constraint conditions of the reliability of distribution network, the number of the switches’action and net loss, finally obtain a optimal group actions that consists of intelligent switches and a sub optimal combination as a backup plan to realize the reconfiguration of the distribution network. The algorithm makes full use of the real-time monitoring function of online monitoring system of equipment in the distribution network, controlling the corresponding switches action reliably through the control command remotely, it can isolate the fault and recovery after network failure quickly and accurately, provides an effective way simple and economical in order to realize the fault self-recovery of distribution network.