Investigation of Distance Protection Applied to the Bahrain Interconnection on the Gulf Cooperation Council (GCC) Power Grid

Energy demands has considerably grown in the GCC states, including Bahrain, which requires for injecting power from other GCC grids. Distance relay performance along the Bahrain interconnection when 600 MW is injected from the GCC network was investigated using DIgSILENT. GCC network, consisting of Bahrain, Kuwait, and back-to-back high voltage direct current (BTB HVDC) link, was modelled to test the distance relay. When 600 MW is injected from Kuwait, the relay was tested when subjected to infeed sources, parallel line outages, resistive faults, power flow reversal, and mutual coupling. Parallel line outages caused underreaching and overreaching issues, and infeed sources caused non-linear measured impedances along the feeders, limiting the settings selectivity. It was observed that quadrilateral relays are superior under resistive faults. When power flow is reversed, blind zone developed for ground faults, and with mutual coupling between double lines, the relay maloperates for ground faults. Short circuit and electromagnetic transient (EMT) simulations were conducted to observe the effects of injecting power from the BTB link. It contributed low fault currents, and harmonics and distortions were produced due to commutation failure. When the BTB link was the main source, the relay significantly underreached. To conclude, a Permissive Overreaching Transfer Trip (POTT) with weak infeed was recommended.