A secure generator distance phase backup protection setting for enhancing generator overexcitation thermal capability during system disturbances

A Secure ANFIS based Relay for Turbo-Generators Phase Backup Protection

“…I R21 ≤ 0.2 for no faults condition The proposed (R and X) ANFIS relay detects (R, X) ANFIS based relay detects phase faults within (370-600 msec) and detects over load conditions within (1030-1830 msec), under various faults, overload, generator loading conditions. The proposed relay also solved the problem associated with the Relay (21) setting as reported in [5].…”

“…Moreover, some of the researchers have proved the existence of a potential problem due to the current setting of Relay (21) when it is set according to the present standards and recent related publications for generator thermal backup protection against transmission line uncleared faults, it is found that the current setting of the Relay (21) for generator thermal backup protection restricts the over excitation thermal capability of the generator [5]. Such a restriction does not allow the generator to supply its maximum reactive power during such events.…”

“…From this point, the necessity of this research work appeared, to present another solution for the Relay (21) setting rather than that described in [5], which was reducing the Relay (21) reach. This solution is based on the ANFIS algorithm.…”

“…This may cause cascading trip events and accelerate power system failure. In addition, the complex setting principle of conventional backup protection may induce hidden failures caused by setting mistakes [2], which would increase the risk of system instability during a disturbance [3,4].Moreover, some of the researchers have proved the existence of a potential problem due to the current setting of Relay (21) when it is set according to the present standards and recent related publications for generator thermal backup protection against transmission line uncleared faults, it is found that the current setting of the Relay (21) for generator thermal backup protection restricts the over excitation thermal capability of the generator [5]. Such a restriction does not allow the generator to supply its maximum reactive power during such events.…”

Impact of Generator Distance Phase Backup Protection on Generator Overexcitation Thermal Capability during System Disturbances

“…Therefore, research is being performed and reported in [2]- [4] to address the coordination between generator overexcitation limiters (OEL) and field overcurrent protection. Furthermore, the coordination between generator distance protection (Relay (21)), generator overexcitation limiters (OEL) and generator overexcited capability limit is being studied and reported only in [5]. The obtained results in [5] based on in-depth dynamic stability studies for SMIB system have shown that the current setting of Relay (21) has a restricting impact on generator overexcitation thermal capability during two common system disturbances, namely a system fault and a sudden application of a large system load while the generator overexcitation limiter (OEL) is in service.…”