EVALUATION AND SELECTION FOR AVAILABILITY IMPROVEMENT OF FREQUENCY CONVERTERS IN ELECTRIFIED RAILWAY

Yasser A. Mahmood, Alireza Ahmadi, and Ajit K. Verma

Keywords

RAM analysis, frequency converter, traction power supply system,availability improvement, multi-criteria decision-making, analytichierarchy process

Abstract

Railway traction power supply systems that work at low frequencies contain frequency converters (FCs) that convert the adequate power from a public grid to a traction grid. Availability and system importance analysis is a key aspect of the overall system perfor- mance. It identifies the weakest areas of a system and indicates where resources must be invested to achieve maximum improvement. Availability analysis of the FC types is crucial to reduce outages of traction power that lead to traffic delays and cancellations due to unavailability of FCs. The aim of this study is to rank FC types on the basis of priority of needs for reliability and maintain- ability improvement so that the availability can be enhanced. The proposed approach involves collection of outage data by calculating performance measures, and then these measures are compared via a comparative chart. Thereafter, opinions of experts are collected and aggregated through linguistic variables, and the FC types are then identified using analytic hierarchy process. Reliability, availability and maintainability have been used as the criteria to identify the FC types. In addition to power sharing, capacity and service factors are considered to be productivity measures. Probabilistic perfor- mance indexes are used to measure availability, maintainability and productivity, whereas the mean number of outages is used as a reliability index.

Important Links:

Go Back