Reliability Evaluation Of Smart Distribution Network

As one of the most fundamental research tasks of power system, reliability evaluation of distribution network has relatively complete research theory and method. With the transformation and upgrading for distribution system from traditional to smart, however, both content and method of reliability evaluation have been changing. For the reliability evaluation of smart distribution network, we should take more factors into account besides those considered in methods of troditional distribution network. For example, distribution automation system, distributed generations(DGs) and maintenance policy. In view of the insufficiency in existing reliability valuation methods, in the paper, we made an in depth research on the impact on smart distribution network reliability of automation system and DGs and maintenance policy, and propose the corresponding algorithm for reliability evaluation respectively which have been simulated on the MATLAB platform. The paper’s main work is as follows:(1) The basic knowledge of reliability evaluation for distribution network, including reliability index and typical methods of reliability evaluation.(2) A method of reliability evaluation under the background of distribution automation. We propose a method of failure mode and effect analysis considering fault disposing procedure which has an impact on all kinds of power supply interrupted districts. The method solves the problem in reliability evaluation under distribution automation effectively by turning the analysis of impact on interrupted districts of fault disposing procedure into the analysis of power states in different interrupted districts.(3) An analytical algorithm of distribution reliability evaluation considering the acess of DGs, in which the model of DGs and loads are probabilistic and an method to calculate the abundance probability of island. The new approach and related analytical formulation of reliability index of loads is proposed in classification under the comprehensive consideration of the fault reconstruction, the types of switches and DGs, the location of DGs and the abundance probability of island.(4) A method of reliability evaluation for distribution network taking preventive maintenance policy in account. We study the influence of preventive maintenance on the failure rate of equipment, in which the preventive maintenance policy is described through reliability function. The failure of equipment is simulated through sequential Monte Carlo method and the lifetime is simulated through reliability function. The operating states and reliability of equipment are recorded through two different clocks which are coordinated by another one named system operating clock.(5) All the methods proposed in the paper are implemented in MATLAB platform, by which we make reliability evaluation to IEEE RBTS BUS6 system and the simulation results verify the rationality and effectiveness of the methods proposed in the paper.