Research On The Technology Of Smart Distribution Grid Self-Healing Control

In order to promote a new round of the energy revolution, all countries in the world have their own ambitious electric power development plans. China is also planning a grand blueprint for grid development. In the past 5 years, the China State Grid Corp is vigorously promoting the construction of a unified strong smart grid. The next five years, power grid will be in perfect phase of ascension as an international leader in the smart grid. As an important part of smart grid, intelligent power distribution network (smart distribution grid) is also the core content of the construction and development.The healing of the distribution network is the core and foundation to realize intelligent power distribution network, and the distribution network reconfiguration is one of the key technologies to realize distribution network self-healing.In the whole power system, the distribution network is directly connected to the users. If the fault occurs, it will have a direct impact on people’s daily life and economic development. Reducing active power loss of distribution network has also been attention and efforts in the direction of the electric power enterprise. With the development of city construction pace accelerating, the user requirements for the power quality and reliability of power supply is also increasing, However, the current our country city power distribution network structure is large and complex.The distribution lines is aging serious and the distribution is messy.What’s more, management and scheduling efficiency is low. Quality and reliability of the power supply can not meet the new requirements. It has a large gap with the developed countries in Europe and America. Distribution network reconfiguration is an effective way to reduce the loss of distribution network. Through the network reconstruction, which can also promote load to be more balanced, eliminate overload, and improve power supply quality and reliability. Therefore, based on the present situation of distribution network in China, to achieve the strategic goals of the smart grid, conducting the thorough research to the distribution network reconfiguration has very important practical and long-term significance.Distribution network reconfiguration is divided into fault recovery after reconstruction and the normal operation of optimal reconstruction. In view of the current situation of distribution network in our country, research on fault after reconstruction of distribution network is particularly urgent and necessary. So, this paper also focuses on the reconfiguration technology of distribution network after fault.The distribution network topology analysis and power flow calculation are the important contents of distribution network reconfiguration. Based on the distribution network topology structure having the characteristics of the radiating, using forward and backward substitution method to calculate each node on the network voltage, branch power, branch current and the total active loss of the network.Distribution network recovery reconfiguration after fault is a nonlinear, multi-objective, and combinatorial optimization problems, and the intelligent optimization algorithms are considered to be the most effective method to solve by many scholars. This paper uses discrete binary particle swarm optimization algorithm (BPSO) to study the solution of distribution network fault recovery reconstruction problem.The establishment of mathematical model for distribution network fault restoration reconfiguration to network active power loss minimization is the reconstruction of the target. In the process of distribution network reconfiguration, first of all, the network structure will be detected. This paper uses the breadth-first search algorithm to detect. For the occurrence of ring networks, the broken circle treatment on the ring network has been chosed. This paper adopts the "minimum break ring method" to modify a ring of power distribution network structure.This paper adopts IEEE33 nodes distribution system and USA PG&E69 nodes distribution system. Programming based on MATLAB8.3 software platform, by analyzing the simulation results, it verifys that the BPSO algorithm being applied to the fault restoration in distribution network reconfiguration is feasible and effective, and it has faster convergence speed and better global convergence ability. Finally, it achieves the goal of the distribution network fault self-healing quickly. In addition, the effects of self-healing have been preliminarily evaluated.