Hardware in the loop simulation and testing of volts per hertz protection scheme for a generator overexcitation system

Abstract

A power plant's large generators are essential components for ensuring the steady production and delivery of electric power for a variety of purposes. A power system's stability is greatly impacted by the generator protection system. It has recently become necessary to think about upgrading the existing protective devices due to a rise in power demand and their aging. The over-excitation, overvoltage, and under-voltage circumstances that affect generators as well as their protection mechanisms were the subject of this study. The analyses of the various method used for generator protection is conducted in this research as part of the literature review. The research developed a logic design and algorithm for volts per hertz protection strategy for overexcited generators. The logic design of over and under-voltage conditions is also developed. The implementation of the current differential and overcurrent protection schemes for generator using DIgSILENT power factory simulation environment is performed and the simulation results are studied for both normal and abnormal conditions for both current differential and overcurrent protection schemes. The lab scale test bench to test volts per hertz, a backup overcurrent, over and under voltage protection schemes for a generator is implemented using SEL 700G IED and simulation results are analysed and presented. The hardware in the loop test-bed is implemented to test analyse the volts per hertz, simple back up overcurrent, and overvoltage and under voltage protection schemes. The HIL test bed was implemented using real time digital simulator and SEL 700G IED. The Hardware-in-the-Loop simulation results for over excitation conditions, overcurrent fault events, over and under voltage conditions of a generator is presented.