Wide-Area Protection Method for Transmission Lines Based on Traveling Wave Energy Comparison

To improve the reliability of conventional protection using traveling wave, a wide-area protection method was proposed based on energy comparison of traveling wave for transmission lines in the period after line fault. Firstly, the fault direction was determined by computing the energy ratio of forward and reverse voltage traveling wave. Secondly, the protection device associated matrix is formed, based on the connection of the lines of the regional power grid and protection devices. Finally, a fault correlation matrix is formed based on the output values of each traveling wave protection device and the protection device correlation matrix, and the fault line was confirmed accordingly. The simulation experiment results indicate that the indicated wide-area protection indicate not only amplifies the fault information, eliminates the influence of the fault line overreach, but also overcomes the problem of protection failure due to the improper start of a protective device. Thus, the reliability and practicability are greatly enhanced.