Component Reliability Modeling of Distribution Systems Based on the Evaluation of Failure Statistics

Abstract

The procedures of asset-management have been developed into a central element of network operation and planning in liberalised electric markets of power supply for the present. The method of asset management considers all relevant life cycle cost related to the network equipment and provides strategies for reinvestment, maintenance and fault elimination. However, the method requires practical information about the available failure statistic from distribution networks, as well as about the reliability evaluation of equipment installed in distribution network. For the quantitative evaluation we collect failure record data of distribution networks in the special failure statistic. Furthermore, this paper represents the first attempt at modeling the component reliability for representative electrical components due to electrical stress, mechanical stress, temperature and time, which takes general aging mechanisms of insulating materials into consideration. Thus the proposed models provide reliability estimates, e.g. failure probability and failure rate for distribution systems. These models can be not only parameterized with a great deal of statistical data but also determined by aging tests and breakdown tests being available for the probabilistic assessment. Our results imply that the assessment approach for component reliability will motivate a need for reasonable and accurate data at an early decision-making stage in future deregulation of electric power market.

Fault causes analysis in feeders of power distribution networks

“…Results shown in Fig. 3 are consistent with [6], which exposes that in distribution networks the primary causes Relative number of incidences (%) for failure are the aging (decrease of electrical strength, thermal strength and mechanical strength) and random failure (environmental causes, accidents, etc).…”

“…Common causes, correlations between causes and feeders types (overhead and underground) can be found. According to [6] the information about the failure cause is of special importance since the consequences of failures can be prophesied and the appropriate measures of maintenance may be devised by evaluating it.…”

Bayesian Network representation of meaningful patterns in electricity distribution grids

“…Failure statistics is a practical technique for component reliability evaluation which is addressed in many previous works [6]- [8], [10], [11], [13]. In this case, failure probability, failure rate, principal failure causes, events classification, and mean-time-between-failures (MTBF) are the most commonly considered indicators.…”

Applicability of auxiliary contacts in circuit breaker online condition assessment

“…International surveys indicate that about 45% of major and 40% of minor failures in CBs are of mechanical origin [9][10][11][12][13][14][15][16][17][18]. An applicable and conventional method to assess the condition of CB mechanisms called the timing test.…”