Paper title: PROPOSAL OF AN ADAPTIVE OVERCURRENT RELAY FOR 110 KV NETWORK
Author(s): IONUȚ CIPRIAN BORĂSCU,
Abstract: Connection of many distributed generations (DG) has a major impact to the setting of
numerical overcurrent relays since the power produced by wind power plants or
photovoltaic power plants varies considerably. Therefore, in order to not exceed the
limits of transportable power in certain sections, in the case of unavailability of a 110 kV
line, territorial power dispatcher imposes operating regimes that have consequences to
numerical overcurrent protections. Since power system is a dynamic system, changing
the source impedance ratio (SIR), affects sensitivity, selectivity or in some cases can
lead to the impossibility of starting the numerical overcurrent relay. Hence, in order to
improve the functionality of a numerical overcurrent protection, under constant modification
of the source behind the relay, the paper is proposing an adaptive overcurrent algorithm
based on the phase to phase differential currents (PDC). As a result, the relay is sensitive to
all types of phase to phase short circuits and the protection area is improved through the
recognition of equivalent impedance source.
Keywords: Network topology, Relays, Fault currents Year: 2015 | Tome: 60 | Issue: 4 | Pp.: 376-386
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