| How to improve the distribution power service and enhance thereliability of the power system is a most important task for utilities.Evaluation of distribution power system caPability and reliability iswidely used in the system planning and operation. In this dissertation,the Beijing downtown area distribution system capability is evaIuatedbased on fuzzy theory according to the present condition of Beijingdistribution system. Factors considered in this dissertation affecting thecapability are including as follows: feeder load rate, voltage offset,network 1oss and N-l analysis. The load allocation in Beijingdistribution system of downtown area is got, and conclusion of thewhole fuzzy distribution caPability is reached.On the basis of the distribution caPability assessment, emphasisis fOcused on the discussion of the reliability modeling and evaluationof distribution system with series and mesh configuration employingtechniques applied in practice. The concept of complex distributionsystem is introduced and the difference between statistic evaluationand predict evaluation is compared. Indices are established for bothstatistic and predict reliability evaluation. In this thesis, load flowalgorithm for radial distribution networks is also discussed. A newalternate iterating algorithm is adopted which shows its efficiency indistribution reliability evaluation. A new algorithm of double --layertree structure to simplify the complex distribution network is proposed,which is used in FMEA to improve the efficiency of distributionreliability evaluation.The new algorithm proposed in this thesis to evaluate thedistribution system reliability is based on the practical operationcondition of Bejing downtown area distriblltion system, consideringthe constraints of neighbor feeds' circuit caPacity margin and voltageoffset at the feeder's terminal. This algorithm is aPplicable for complexradial networks. Its efficiency has been tested in practical distributionsystem. There is also detailed analysis in this thesis about the effect ofdistribution automation aPpliance and distribution system capability onthe reliability of distribution system. |
