In power system networks, protection has to be designed such that protective relays
isolate the faulted portion of the network, to prevent equipment damage, injury to
operators and to ensure minimum system disruption enabling continuity of service to
healthy portion of the network.
Power system analysis is a very critical part in any electrical design and its
operation. Relay coordination study or relay coordination calculation is a part of
the traditional power system analysis performed for all plants and facilities for a
smooth operation. Relay coordination studies plays a vital role in the electrical
maintenance and plant operation.
Relay coordination is used to achieve proper fault identification and fault clearance
sequence. These relays must be able to differentiate between the normal operating
currents that including short time over currents that may appear due to certain
equipment normal operation such as motor starting currents, Transformer inrush
currents and sustained overcurrent due to fault conditions. power system relaying
and overcurrent protection are mutually dependent concepts which contribute to the
plants smooth operation. Protection coordination or protective device coordination
study will include the protection relay setting calculation and the power system
protection and switchgear, MCB, Fuse, ACB, VCB so on.
In order to provide the overcurrent protection we need to properly conduct the power
system protection and the protective device coordination study with our compromising
the electrical safety of the system. The main object of the protection coordination
is to avoid nuisance tripping by proper protection relay setting calculation by
enabling the power system protection. During fault conditions, these relays must
operate quickly so as to isolate the faulted part of the network only and allowing
for continued operation of the healthy circuits.
Our Relay Coordination Study Methodology:
Our dedicated electrical professional team will visit your ream and collect all the
data. For conducting a relay setting calculation we need all the electrical
installation data of the plant and their complete behaviour manuals. Power system
relaying is configured by the OEMs as a standard international practice and the
manufactured will have a defined parameters with respect to the behaviour of the
equipment. Once the data is collected we model the data collected in the reputed
electrical simulation software ETAP /SKM. The data modelled will be integrated with
the OEM library for setting the configuration values. The modelled network will be
subject to various simulation studies like voltage drop analysis, short circuit
studies and protective device coordination studies. The fault current calculation
shall be done to identify what is the maximum available fault current at each and
every feeder and bus. IEEE short circuit current calculation sheets will provide you
the values of the 3 phase bolted and arcing fault. We have to use these short
circuit calculation values obtained to perform relay coordination calculation. Relay
setting calculation will depend on the fault current calculation and the time
values.
- Data Collection
and SLD Preparation
- Short Circuit Studies
- Relay Coordination Studies
- Implementation