Informatics Publishing Limited

Abstract

Reliability indices are parametric quantities used to assess the performance levels of electrical power distribution systems.

In this work, a generalized quadratic model is developed for electrical power distribution system contributions to system reliability indices using Ikeja, Port-Harcourt, Kaduna and Kano distribution system feeders as case studies.

The mean System Average Interruption Duration Index (SAIDI), System Average Interruption Frequency Index (SAIFI) and Customer Average Interruption Duration Index (CAIDI) contributions to system reliability indices for Ikeja, Port-Harcourt, Kaduna and Kano distribution systems were 0.0033, 0.0026, 0.0033 and 0.0018 respectively due to the fact that a prolonged period of interruptions was recorded on most of the feeders attached to Port-Harcourt and Kano distribution systems making them to be less reliable compared to Ikeja and Kaduna distribution systems.

The generalized Quadratic model forms a basis for a good design, planning and maintenance of distribution systems at large.

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Abstract

This paper discusses the transfer function method as a tool for detection of winding deformations in power transformers. A series of transfer function measurements on selected transformer rating were carried out on the active part within the transformer and thereafter without bushings, oil and tank. using a network analyzer. The new transfer functions were measured after the application of the vertical and radial deformations to the windings and after the replacement of the active part in the tank and oil refilled. For this particular transformer construction, it is evident that only vertical deformations can be detected by the transfer function method.

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