Voltage and frequency protection
The ARGUS 8 series of voltage and frequency
relays are numerical, multi-function devices that are
designed to be applied for the protection of
transmission, distribution and industrial systems.
ARGUS 8 can be used for load shedding and other
protection purposes, and can provide phase under
and over voltage, neutral displacement overvoltage,
negative sequence overvoltage and under and
overfrequency protection elements.
ARGUS 8 is part of the comprehensive range of
ARGUS-platform based numeric relays. These
relays have extensive control functions, which are
supplemented by advanced metering, data storage
and fibre-optic communications. Supervisory and
self monitoring features give added confidence to
the user as well as reduced maintenance and down
time. A menu-based interface gives user-friendly
access to relay settings, meters and operational
data.
FEATURES
• Each phase voltage element can be
configured for undervoltage or overvoltage
• With 2 or 3 phase measurement each
element can be configured to require
operation of any phase or all phases.
• Negative sequence overvoltage with two
elements
• Neutral voltage displacement with two
elements
• Four independent frequency elements, each
of which can be configured for
underfrequency or overfrequency
• Frequency elements can be blocked by
voltage elements, enabling simple logic
schemes
• Independent definite time delays for each
element
• Modbus IEC 60870-5-103 protocol for
communicating
• Fibre optic or RS485 electrical
communication
• Fault, event & waveform recorder
• Starter & trip LED Indication
DESCRIPTION
The protection functions available in ARGUS 8 have
many possible applications, some of which are
mentioned within the descriptions below.
Undervoltage and overvoltage
Four independent elements are supplied, each of
which can be set to operate for undervoltage or
overvoltage conditions and all having separate
definite time delay elements. These can be used to
protect generators against overvoltages, motors
against loss of supply or applied as backup
protection in the event of defective system
regulating equipment.
Negative sequence overvoltage
Two independent elements are supplied, each of
which has a definite time delay element. These can
be used to monitor the quality of the supply and
protect plant or feeders against system unbalance.
Neutral voltage displacement
Two independent elements are supplied, each of
which has a definite time delay element. These can
be used to detect earth faults in high impedance
earthed or isolated systems. For this feature, the
residual voltage can be measured directly from an
open delta tertiary winding or calculated internally
from the three phase voltage inputs.
These elements include a third harmonic filter,
which de-sensitises the elements to any
superimposed third harmonic frequencies.
Underfrequency and overfrequency
ARGUS 8 – 200/ 300 series only.
Four independent elements are supplied, each of
which can be set to operate for underfrequency or
overfrequency and all having separate definite time
delay elements. These can be applied wherever
frequency protection is required to maintain system
stability e.g. in load shedding schemes. The
accuracy and security of operation of the numeric
algorithms enables the relay to be employed to
detect any frequency abnormalities.
SYSTEM DATA
ARGUS 8 variants with two voltage inputs have a ' 2
Systems A/ B‘ connection setting. This allows two
different systems each to be assigned two of the
under/ overvoltage elements, using one of the
voltage inputs for each system.
This feature could be used as part of a local
generation scheme with islanding capability, where
one input is allocated to the local system, and the
other to the grid. |
Indotrade Priority 16th Year
