Improving Efficiency and Reliability of Protection System of Tarbela Power Station

Protective relaying system plays a vital role in ensuring the proper and smooth functioning of the Power plant. As the generator is the most expensive part of the plant that’s why the provision of a healthy protection system is must. Protection system guarantees the reliability and safe operation of the plant and is called the brain of the power system. Tarbela is the largest power plant of Pakistan and considered as a back bone of power system of Pakistan. In this paper, the generator protective relay of Tarbela power plant is tested and their results are presented. All the protective relays of Tarbela Power Plant are of electromechanical types which were manufactured in 1970-80. Setting, calculation and test result of these relays were then analyzed and recommendation is made for improving the reliability of the protection system of the said plant. Features of new numerical relays and comparison with the installed relays are also presented and finally the description of upgradation/retrofitting of installed electromechanical relay are discussed for smooth transition to new technology.