Influence Degree of Multiple Faults on Reliability Indices of Distribution System

In the reliability evaluation of distribution system,due to the large number of its components whether the multiple-fault is taken into account or not will influence the confidence of evaluation indices,however the work amount of evaluation will be evidently increased when multiple faults are considered,thus rational accepting or rejecting of multiple faults have to be performed.In this paper,a method of multiple faults influence degree analysis (MFIDA),which is used to analysis the influence degree of multiple faults on reliability indices of distribution network,is proposed,and the expression of ratio of multiple faults’ occurrence probability to that of single fault is derived,and it is pointed out that more number of system components and longer yearly outage hours of components will make a bigger influence of multiple faults on system reliability indices,and it is also pointed out that in the processing the maintenance time of single component can be regarded as single fault.So it can rationally accept or reject multiple faults.