A case study on reliability improvement of 10 worst performing feeders in Niagara Mohawk Power Corp. (NMPC) service territory

This case study demonstrates the reliability improvement initiative taken by Niagara Mohawk Power Corporation (NMPC), to analyze 10 of their worst performing feeders. The CYMDIST-RAM (Reliability Assessment Module) from CYME International Inc. was used for the analysis. The program computes system indices (SAIFI, SAIDI, CAIDI etc.) and load point indices (interruption frequency, outage duration etc.) for each zone on the feeder, based on the failure rates and repair times input by the user. Load indices of a zone reflect the trouble areas within a feeder, and are useful for micro-analysis. Variation of different indices along a feeder may be displayed as a color code. Indices may also be reported on the one-line diagram, and as reports in various formats (spreadsheet, Excel, ASCII etc.). Corrective measures such as device addition/relocation, tree-trimming, fault locators were attempted and reliability improvement was assessed in terms of saved CHI (customer-hrs interrupted). Different projects were ranked according to the cost benefit factor (nvestment/CHI saved)