|
New & Emerging Technologies |
|
The Company strived hard to provide the needed focus on use of new and emerging technologies and innovative techniques for an enhanced performance. Some of the areas where the new technologies were used by the Company include :
Numerical Relays Nearly 170 numerical relays of different makes for protection of lines as well as power transformers are in service in MP TRANSCO grid since the year 2003 and the information provided by these relays for different types of faults has been found extremely useful for fault analysis. Numerical differential relays in particular have proved their worth by preventing failue of incomer CTs at a few places by detecting changes in currents due to developing faults in CTs and ensuring timely tripping of transformers. The Company has, also, evolved a programme for phased replacement of additional 168 Nos. old sluggish relays by these latest type of relays before September, 2006. Fault Analysers Effective use of Portable Digital Three-phase Off line Overhead Transmission Line Fault Analyzer System has been made by the Company not only for break-down maintenance, but also preventive maintenance. This equipment is very sensitive and accurate and it has been possible to locate the faults with an accuracy of + 50 metres. This system has been extensively used and has proved its worth by reducing downtime of EHV lines by around 30%. Punctured Insulator Detectors Use of punctured insulator detectors has not only proved to be a vital tool for effective preventive maintenance, but has also reduced cost of maintenance. Earlier due to puncture of disc, the entire insulator string was being replaced because of difficulty in pinpointing the defective disc in the string. Now with the advent of this equipment, it is possible to pinpoint the defective disc, which alone is being replaced using hot line technique. This has helped in reducing the cost of replacement as also outages developing on account of punctured discs. Thermo Vision Scanning: Thermo-vision scanning is prevalent in power sector for more than two decades. However, during past two years development in this technology has been unbelievable. Presently, precision wide lense thermo-vision equipments are available, which facilitate large area scanning even in day light and also provide a comparison of pre and post scanned object. Temperatures are recorded in the microprocessor, which facilitate use of equipment at a stretch for scanning of more than 100 joints. In MP Transco, extensive use of this equipment is being made not only for the purpose of scanning of weak joints alone, but also efforts have been made to compare the operating temperature of CTs and VTs in the same bay. In few substations, it was found that one of the CT/PT (out of set of three) was operating at a high temperature compared to the others. The equipment was taken out for maintenance and it was found that oil characteristics in the equipment have lowered down and also loose connections were found therein. Maintenance was done to save the equipment. Thermo-vision scanning, therefore, will write its own history in the power sector, if full advantage of the facilities provided by the technology is taken. For this equipment as well as critical equipments of this nature, MP Transco has developed a system of maintaining equipment-wise log book to record history of each operation as also utilization schedule for the equipment. Leakage Current Monitors for Metal Oxide Surge Arresters: Lightning arrestor has always been an equipment causing anxiety for system operators because inspite of not so good quality surge monitors installed with the equipment, the healthiness of this equipment always remains doubtful. Presently leakage current monitors have been developed which provide the facility for monitoring of leakage current in surge arrestors without disconnecting them from service. This equipment has been found to be very accurate and is extensively being utilized to verify healthiness of lightning arrestors installed at all critical points in the EHV substations. Hot Line Tools: MP Transco has adequate quantum of hot line tools imported from USA, which are effectively being utilized for hot line maintenance and also bare hand working on 220kV and 400kV transmission lines. We have the required infrastructure and trained staff for undertaking this job, which has resulted into considerable economy because of avoidance of shutdown for normal maintenance. Precision Transformer Winding Resistance Measuring Kit: Precision transformer winding resistance measuring kit for EHV power transformers has almost proved to be a boon to the Company in locating certain critical faults, which during routine maintenance and testing remain undetected. Whenever major tripping of a power transformer takes place, now a practice has been introduced to verify the resistance of transformer winding apart from other investigations, which were normally being done to verify and remedy the cause of tripping. In as many as 12 cases, measurement of winding resistance indicated certain abnormalities, which if not attended in time, would have resulted into failure of transformers. Looseness in bushing lead, tap-changer lead, breaking of lugs in selector switch, loosening of copper flexible lead in diverter switch etc. are some of the problems which got detected merely by measuring the resistance of the winding. These precision resistance measuring kits are now extensively being used for preventive maintenance of EHV transformers. *********** |