The “Generator rotor overload protection” function is used to protect the rotor winding against excessive temperature as a result of overcurrents. The functions operating characteristic is designed in accordance with the American standard IEEE-C50.13.
For more detailed information on “Generator rotor overload protection” function, refer to ABB, Relion 670 Series manuals.
The “Generator stator overload protection”, is used to protect the stator winding against excessive temperature as a result of overcurrents. The functions operating characteristic is designed in accordance with the American standard IEEE-C50.13.
For more detailed information on “Generator stator overload protection” function, refer to ABB, Relion 670 Series manuals.
Inadvertent or accidental energizing of off-line generators has occurred often enough due to operating errors, breaker head flashovers, control circuit malfunctions, or a combination of these causes. Inadvertently energized generator operates as induction motor drawing a large current from the system. The voltage supervised overcurrent protection is used to detect the inadvertently energized generator. “Accidental energizing protection for synchronous generator” takes the maximum phase current input and maximum phase to phase voltage inputs from the terminal side.
For more detailed information on “Accidental energizing protection for synchronous generator” function, refer to ABB, Relion 670 Series manuals.
The “Average power transient earth fault protection” is a transient measuring directional earth-fault protection. Determination of the earth fault direction is based on the short-term built-up transient at the beginning of the earth fault. This transient is to a large extent independent of the neutral point treatment. This means that the function can be used without any modification in all types of high-impedance grounded, resonant grounded or isolated power systems.
For more detailed information on “Average power transient earth fault protection” function, refer to ABB, Relion 670 Series manuals.
Reset of the function including all
internal calculations and all outputs
APPTEF Output signals
APPTEF Output signals
Name
Type
Description
TRIP
BOOLEAN
Trip for earth fault in forward direction
STFW
BOOLEAN
Start in forward direction
STRV
BOOLEAN
Start in reverse direction
STUN
BOOLEAN
Start of the residual overvoltage stage 3Uo>
STIEF
BOOLEAN
Intermittent earth fault detetcted
WRNFW
BOOLEAN
Warning, a transient corresponding to the forward fault
has been detected
ALMCC
BOOLEAN
Alarm when cross country fault condition is detected by
3Io measurement. Transient EF function will be prevented to make any
directional decision while this signal is active.
ALMCIRI
BOOLEAN
Alarm when 3Io circulating current is detected, which can
influence the Io*cos(Phi) calculations. Pickup for Io*cos(Phi) part will be
adjusted accordingly. 3Io circulating current shall be reduced by appropriate
action in the primary system.
IFUNDRE
REAL
Integrated real part (proportional to active power) of the
fundamental frequency phasor in the residual current 3Io, given in primary
amperes
IFUNDIM
REAL
Integrated imaginary part (proportional to reactive power)
of the fundamental frequency phasor in the residual current 3Io, given in
primary amperes
IHARMIM
REAL
Integrated imaginary part (proportional to harmonic
reactive power) of the lumped harmonic phasors in the residual current 3Io,
given in primary amperes
APPTEF Non group settings (basic)
APPTEF Non group settings (basic)
Name
Values (Range)
Unit
Step
Default
Description
GlobalBaseSel
1 – 12
–
1
1
Selection of one
of the Global Base Value groups
APPTEF Group settings (basic)
APPTEF Group settings (basic)
Name
Values (Range)
Unit
Step
Default
Description
Operation
Off
On
–
–
Off
Operation Off / On
OperationMode
Start Only
Start and Trip
–
–
Start Only
Operation mode ( Start Only / Start and
Trip )
tPulseMin
0.02 – 1.00
s
0.01
0.15
Minimum pulse length duration in
seconds, for trip and/or start outputs
UN>
5 – 80
%UB
1
30
Minimum threshold level for residual
overvoltage start condition 3Uo>
IN>
3 – 100
%IB
1
5
Minimum threshold level for residual
overcurrent start condition 3Io>
IMinForward
1.5 – 100.0
%IB
0.1
2.5
Minimum operate level for integrated
current in order to declare the forward direction
IMinReverse
1.0 – 100.0
%IB
0.1
1.5
Minimum operate level for integrated
current in order to declare the reverse direction
tStart
0.04 – 2.00
s
0.01
0.15
Minimum time delay to declare EF
direction in seconds. Timer will be activated with STUN signal.
tReset
0.05 – 5.00
s
0.01
0.5
Drop off time delay added to 3Uo
overvoltage condition start signal STUN, after which the function will be
fully reset
tTrip
0.00 – 20.00
s
0.01
2.00
Minimum trip time delay in seconds
after STFW signal has been issued
UN>StartsNo
2 – 20
–
1
4
Minimum number of consequitive 3Uo>
start conditions to detect intermitten EF. Note that this counting will only
be active while reset timer is running.
APPTEF Group settings (advanced)
APPTEF Group settings (advanced)
Name
Values (Range)
Unit
Step
Default
Description
OperationCC
Off
On
–
–
On
Operation of cross country fault
detection On/Off
CrossCntry_IN>
20 – 1000
%IB
1
120
Operate 3Io current level for cross
country fault detection
tCC
0.02 – 1.00
s
0.01
0.03
Time delay in seconds to activate cross
country fault detection
Circulate_IN>
2 – 200
%IB
1
10
Operate 3Io current level for
circulating current detection
tCircIN
5.0 – 60.0
s
0.1
10.0
Time delay in seconds to activate
circulating current detection
APPTEF Monitored data
APPTEF Monitored data
Name
Type
Values (Range)
Unit
Description
INRMS
REAL
–
A
RMS value of residual current 3Io
UNMAG
REAL
–
kV
Magnitude of fundamental frequency
phasor for measured neutral voltage 3Uo in primary kV
ANGDIF
REAL
–
deg
Phase angle difference between rotated
-3Uo voltage phasor and 3Io current phasor in degrees
Integrated real part (proportional to
active power) of the fundamental frequency phasor in the residual current
3Io, given in primary amperes
IFUNDIM
REAL
–
A
Integrated imaginary part (proportional
to reactive power) of the fundamental frequency phasor in the residual
current 3Io, given in primary amperes
IHARMIM
REAL
–
A
Integrated imaginary part (proportional
to harmonic reactive power) of the lumped harmonic phasors in the residual
current 3Io, given in primary amperes
Logics & highlights
Example Substation
Simplified zero-sequence equivalent circuit during an EF in Feeder 1
Flow of active power in the zero-sequence system at the moment when EF happens
Active power based on fundamental frequency
Deriving Iocos(ɸ) and Iosin(ɸ) quantities from -Uo and Io phasors
Example how waveforms and the active power signals may look like for a faulty feeder
Example how waveforms and the active power signals may look like for a healthy feeder
Reactive power calculation
Example how waveforms and the summed harmonic reactive power signals may look like for a faulty feeder
Example how waveforms and the summed harmonic reactive power signals may look like for a healthy feeder
Simplified logic for measurement part of the APPTEF function
Residual over-voltage start logic and reset logic
Intermittent EF start logic
Start and Trip logic for an EF in forward direction
The “Negative sequence time overcurrent protection for machines” is intended primarily for the protection of generators against possible overheating of the rotor caused by negative sequence current in the stator current. NS2PTOC can also be used as a backup protection, that is, to protect the generator in case line protections or circuit breakers fail to clear unbalanced system faults.
For more detailed information on “Negative sequence time overcurrent protection for machines” function, refer to ABB, Relion 670 Series manuals.
Shunt Capacitor Banks (SCB) are used in a power system to provide reactive power compensation and power factor correction. They are as well used as integral parts of Static Var Compensators (SVC) or Harmonic Filters installations. The “Capacitor bank protection” function is specially designed to provide protection and supervision features for SCBs.
For more detailed information on “Capacitor bank protection” function, refer to ABB, Relion 670 Series manuals.
The “Thermal overload protection” estimates the internal heat content of the transformer (temperature) continuously. This estimation is made by using a thermal model of the transformer with two time constants, which is based on current measurement.
For more detailed information on “Thermal overload protection, two time constants” function, refer to ABB, Relion 670 Series manuals.
The “100% stator earth fault protection” is used to detect earth faults in the stator windings of generators and motors. STTIPHIZ is applicable for generators connected to the power system through a unit transformer in a block connection.
For more detailed information on “100% stator earth fault protection, injection based” function, refer to ABB, Relion 670 Series manuals.
The “Under impedance protection” function is a three zone full scheme impedance protection using offset mho characteristics for detecting faults in the generator, generator-transformer and transmission system. The three zones have fully independent measuring loops and settings.
For more detailed information on “Under impedance protection for generators and transformers”, refer to ABB, Relion 670 Series manuals.
In the “Line differential protection, 3 or 6 CT sets” function, the L3CPDIF is used for conventional two-terminal lines with or without a 1½ circuit breaker arrangement in one end, as well as three-terminal lines with single breaker arrangements at all terminals. The L6CPDIF is used for conventional two-terminal lines with 1½ circuit breaker arrangements in both ends, as well as multi-terminal lines with up to five terminals.
For more detailed information on “Line differential protection 3 or 6 CT sets, with in-zone transformers”, refer to ABB, Relion 670 Series manuals.
