Impact of STATCOM on Distance Relay Operation for Various Types of Faults
Ali Abdolkhani1, PeymanS.Bandaghiri2, FarzadA. Rocky3
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Flexible AC Transmission (FACT) devices are normally used to to enhance controllability and increase power transfer capability of the grid. However, in power systems grids, presence of FACT devices such as STATCOM (Static Synchronous Compensator) usually affects the operation of some sub-systems such as distance relays. It is very important that the distance relays do not mal-operate under system fault conditions as this will result in the loss of stability or the security of the system. As STATCOM devices have fast response and their functional characteristics and control system introduce dynamic changes during fault conditions in a transmission line it is important that distance relays perform correctly irrespective of such dynamic changes introduced during fault. This paper presents a complete analysis of distance relay operation in the presence of STATCOM for all types of faults. It has been found from the simulation results that the operation of distance relays prone to either under-reach or over-reach when a STATCOM installed at the mid-point within the protection zone of the relay.