Powergrid Corporation of India Limited (POWERGRID) is one of the largest transmission utilities in the world. It owns and operates upwards of 47,000 circuit kms of transmission lines of voltages ranging from 66 kV to 800 kV AC and ± 500 kV HVDC & 81 substations with transformation capacity of approximately 47,000 MVA.
With the growing need to maintain high reliability of the system, a tool has been developed to address the voluminous data related to outages of lines and various equipments. In this era of increasingly high competition and with the aim of POWERGRID to achieve an availability figure of above 99% it is necessary to pin-point the weaknesses of the system and to analyze faults accruing therefrom. The data in the current context has been analysed for Northern Region-I of POWERGRID for the period April 2003 to December 2004. Such an exercise is the beginning and will continue to keep up to ever increasing standards.
For the analysis, Microsoft Access is used as the Database management system which serves as an interface between a common database and software programme. The system uses a three level database model-the physical database organization, the logical database organization and the application programme files which have been written in ASP and SQL to extract the relevant data into meaningful form so that analysis can be performed.
This paper aims to estimate failure rates and restoration time for overhead lines as functions of operating voltage, circuit length, to generate a data base for analysis of three phase faults, pollution related failures etc. This analysis becomes all the more necessary as certain lines of POWERGRID are terminating at substations owned by other utilities and outages at such terminals cause disruption of power thus decreasing availability of the system.
Outage rates, Outage frequency, Fault analysis, Database management systems, Active server pages
