Busbar differential protection in conjunction with a current transformer compensating algorithm

A novel distributed unit transient protection algorithm using support vector machines

“…Thus, if one protection unit is in failure or out of service, other protection units would not be affected and could still maintain normal operation, namely each protection unit is independent. Traditional busbar protection algorithms need the information of all the lines connected with it [8][9][10][11][12][13], and they cannot be operated normally if the information of any of the lines had gone wrong. Accordingly, compared with traditional protection methods which depend on the information of all the connected lines, the reliability of the proposed algorithm could be sufficiently improved.…”

“…According to the direction of the detected initial travelling wave, an extra high-speed busbar protection technique was proposed in [10], nevertheless it must detect the initial travelling waves on all connected lines, i.e., the whole protection could not be operated normally if any unit was disabled to judge fault travelling wave direction. Based on the third-difference function of the current, [11] proposed a current transformer compensating algorithm to protect busbar. In addition, [12] presented a novel wavelet-transform-based directional algorithm for busbar protection, where only the high-frequency details at the first level were employed.…”

“…Furthermore, [14] combined several protection principles and measuring techniques into a scheme with minimum CT performance requirements, which enhanced the performance of busbar protection to some extent. However, due to the deficiency of neglecting the impacts of the transition resistance and fault initial angle [6][7][8][9][10][11][12][13][14], the reliability of traditional transient protection methods cannot be guaranteed whilst their performance are not stable enough, thus limiting their wide utilization in reality. Overall, all these methods need information of all lines connected to the busbar, which may lead to the complexity of such methods and the poor reliability of the protection schemes.…”

CT dimensioning for transmission line protections-an investigation into increasing saturation tolerance for protection functions

“…A method-based third difference function was presented in Reference [1]. Wavelet transforms have also been used for primary current regeneration from the saturated secondary currents [2].…”

A novel measurement technique for extra high voltage bus bar fault detection

“…Current transformer (C.T.) saturation during external faults has been a major problem for the different types of differential relays; however several algorithms have been implemented to overcome such a problem [3,4]. Digital relaying made use of the information given by the transient components associating fault conditions to fully identify busbar fault presence, besides solving the problem of wrong trip due to C.T saturation.…”