Traveling Wave-Based AC Transmission Line Protection using One Terminal
Line transmission protection, traveling waves, one-terminal protection
A fast protection method increases the electrical power system stability, avoids damages to system components, and reduces power quality issues effects, benefiting all the electrical power system agents. The transmission lines are extremely important to the electrical system since it connects the generation units to the consumers. Therefore, problems in the transmission system has the potential of affecting all the power system. The transmission line protection based on traveling waves proposes to be the fastest protection method. The traveling waves are high frequency electromagnetic transients that arise in the voltage and current signals after an event inception in the transmission line, as a fault. Two-terminal protection schemes based on traveling waves are easier developed and implemented than one-terminal ones, but need communication and, normally, data synchronization systems among the two line terminations, which demands costs and presents technical drawbacks. This work pretends to investigate the traveling waves protection principles and, at the end, will propose anone-terminal transmission line protection based on traveling waves with no need of a communication and, obviously, data synchronization systems.The proposal of this research includes performing the equation of the sampling frequency effects in the one-terminal protection, which was not perform until now. Furthermore, classic issues related to protection based on traveling waves, such as fault close to the line terminals and the traveling waves velocity estimation, will be detailedlyequated in order to present solutions to such problems. The research will be evaluated by means of computational simulations in a 500 kV transmission system based on Brazilian and Chinese systems with the lines modulated at distributed parameters. At the end, it is expected that a fast and reliable one-terminal transmission line protection based on traveling wave method be proposed.