Iskra FPC 200 User manual
Content
1 USER MANUAL FPC 200 - 3/2017
FPC 200
USER MANUAL
Mar 2017
jun-2016
Feeder F1 and F3
Motor M1 and M3
Busbar B2 and B3
Transformer T1 and T3
Content
2 USER MANUAL FPC 200 - 3/2017
Preface
Copyright
Copyright © Iskra d.d. Ljubljana, Slovenia 2016. All rights reserved. Dissemination or reproduction of this document, or
evaluation and communication of its contents is not authorized except where expressly permitted.
Purpose of this manual
The manual describes the functionality, as well as operation, installation and commissioning instructions for the FPC 200
types F1, F3, M1, M3, B2, B3, T1 and T3.
Target audience
Protection engineers, mechatronic engineers, commissioning engineers, personnel concerned with setting, monitoring
and service of protection equipment, industrial automatic and control facilities and personnel of electrical facilities and
power plants.
Applicability
This manual is valid for all FPC 200 type multifunctional numerical relays.
Conformity
This product complies with the Low Voltage Directive 2014/35/EU and EMC Directive 2014/30/EU. This
conformity has been proved by tests according to product standards IEC 60255-26 (for EMC directive)
and IEC 60255-27 (for Low Voltage Directive).
Liability statement
Specialists and responsible persons of Iskra d.d. has checked the contents of this manual to ensure the description of both
hardware and software are as accurate as possible. However, deviations from the description cannot be completely ruled
out, so that no liability can be accepted for any errors or failures contained in the given manual. The content of this
manual is reviewed regularly. Corrections will be included in following editions. Any suggested improvements are highly
appreciated. We reserve the right to make technical improvements without notice.
Content
4 USER MANUAL FPC 200 - 3/2017
Safety symbols and messages
The warnings and notes contained in this manual serve for your own safety as well as safety of people and property
around you. Please observe them!
The following indicators and standard definitions are used:
DANGER
Indicates an imminently hazardous
situation which, if not avoided, will result
in death, serious injury or property
damage.
WARNING
Indicates a potentially hazardous situation
which, if not avoided, could result in death,
serious injury or property damage.
CAUTION
Indicates a potentially hazardous situation
which, if not avoided, could result in
minor or moderate injury of property
damage.
NOTE
Indicates information about the device or
respective part of instruction manual
which is essential to highlight.
Explanation of device safety symbols
Depending on the device layout, the following labels and symbols can be used on device itself or in the
corresponding technical documentation:
WARNING!
Risk of electrical shock!
CAUTION!
Refer to product technical documentation!
Protective and functional ground terminal.
Waste Electrical and Electronic Equipment (WEEE) Directive 2002/96/EC; the affixed
product label indicates that you must not discard this electrical / electronic product in a
domestic household waste.
Content
USER MANUAL FPC 200 - 3/2017 5
Warning
Only qualified personnel can work on this device. Certain parts of the device inevitably have dangerous voltage. Thorough
familiarity with all warnings and safety notices of this manual along with applicable safety regulations is required. Failure
to observe these precautions can result in fatality, personal injury or extensive material damage. The successful and safe
operation of this device is dependent on proper handling, installation, operation and maintenance by qualified personnel.
QUALIFIED PERSONNEL
For the purpose of this manual and product, a qualified person is the one who is familiar with the
installation, construction and operation of the equipment and hazards involved. Following qualifications are
needed:
Knowledge to energize, de-energize, clear, ground and tag circuits and equipment in accordance
with established safety practices.
Knowledge of proper care and use of protective equipment in accordance with established safety
practices.
Proficiency in rendering first aid.
NOTE
This is a class A product. In a domestic environment this product may cause radio
interference in which case the user may be required to take adequate measures.
Content
6 USER MANUAL FPC 200 - 3/2017
Content
Preface ..................................................................................................................................................................................... 2
Copyright.............................................................................................................................................................................. 2
Purpose of this manual ........................................................................................................................................................ 2
Target audience ................................................................................................................................................................... 2
Applicability ......................................................................................................................................................................... 2
Conformity ........................................................................................................................................................................... 2
Liability statement ............................................................................................................................................................... 2
Contact................................................................................................................................................................................. 3
Safety symbols and messages.............................................................................................................................................. 4
DANGER ........................................................................................................................................................................... 4
WARNING ........................................................................................................................................................................ 4
CAUTION.......................................................................................................................................................................... 4
NOTE................................................................................................................................................................................ 4
Explanation of device safety symbols.............................................................................................................................. 4
Warning ............................................................................................................................................................................... 5
Content..................................................................................................................................................................................... 6
1Introduction................................................................................................................................................................... 10
1.1 Presentation ......................................................................................................................................................... 11
1.2 Selection table ...................................................................................................................................................... 12
1.3 Device description ................................................................................................................................................ 13
Connection configuration ................................................................................................................................. 13
2Functionality .................................................................................................................................................................. 14
2.1 Protections in general........................................................................................................................................... 15
Default values................................................................................................................................................... 15
Protection operation range .............................................................................................................................. 15
Time characteristics.......................................................................................................................................... 17
2.2 Current based protections.................................................................................................................................... 20
Overcurrent protection - ANSI code 50/51 ...................................................................................................... 20
Earth fault overcurrent protection - ANSI code 50/51|N/G............................................................................. 22
Negative sequence/unbalance overcurrent protection - ANSI code 46........................................................... 24
Restricted earth fault protection - ANSI code 64REF ....................................................................................... 26
Phase undercurrent protection - ANSI code 37................................................................................................ 28
Inrush restraint................................................................................................................................................. 30
Content
USER MANUAL FPC 200 - 3/2017 7
2.3 Voltage based protections ....................................................................................................................................32
Phase to phase overvoltage protection - ANSI code 59....................................................................................32
Neutral voltage displacement - ANSI code 59N................................................................................................34
Phase to phase undervoltage protection - ANSI code 27 .................................................................................36
Positive sequence undervoltage protection - ANSI code 27D ..........................................................................38
Remanent undervoltage protection - ANSI code 27R.......................................................................................40
2.4 Frequency based protections................................................................................................................................42
Overfrequency protection - ANSI code 81H .....................................................................................................42
Underfrequency protection - ANSI code 81L ....................................................................................................44
Rate of change of frequency protection - ANSI code 81R ................................................................................46
2.5 Power and machine protections ...........................................................................................................................48
Thermal overload protection –ANSI code 49T.................................................................................................48
Machine Thermal Overload Protection - ANSI code 49M.................................................................................50
Temperature monitoring - ANSI code 38/49T ..................................................................................................53
Locked rotor protection, excessive starting time - ANSI code 48/51LR/14 ......................................................55
Starts per hour - ANSI code 66..........................................................................................................................57
Buchholz relay protection –ANSI code 63........................................................................................................58
Thermal switch protection –ANSI code 26.......................................................................................................59
2.6 Automation and diagnostic ...................................................................................................................................60
Circuit breaker control and monitoring - ANSI 94/69 with integrated circuit breaker failure - ANSI 50BF/62BF
function..........................................................................................................................................................................60
Trip circuit supervision - ANSI 74 - TCS .............................................................................................................66
Auto-reclosing function - ANSI 79 - AR .............................................................................................................69
Machine control................................................................................................................................................72
External trip –EXT-T .........................................................................................................................................74
2.7 User defined signals ..............................................................................................................................................75
Description........................................................................................................................................................75
Assigning user defined signals to digital outputs..............................................................................................75
Blocking of individual protection ......................................................................................................................75
2.8 Disturbance recording...........................................................................................................................................76
Description........................................................................................................................................................76
USB stick ...........................................................................................................................................................76
Trigger...............................................................................................................................................................76
Recorded data...................................................................................................................................................76
Clearing disturbance records ............................................................................................................................76
Setting parameters ...........................................................................................................................................77
2.9 Measurements ......................................................................................................................................................78
Presented measured values..............................................................................................................................78
Content
8 USER MANUAL FPC 200 - 3/2017
Nominal values ................................................................................................................................................. 78
Current measurement ...................................................................................................................................... 78
Voltage measurement ...................................................................................................................................... 78
Frequency measurement ................................................................................................................................. 78
Symmetrical components................................................................................................................................. 79
Temperature..................................................................................................................................................... 79
2.10 Self-diagnostic....................................................................................................................................................... 80
System status register.................................................................................................................................. 80
Operating states........................................................................................................................................... 80
Internal faults description ............................................................................................................................ 81
3Communication ............................................................................................................................................................. 82
3.1 Modbus RTU ......................................................................................................................................................... 82
General description .......................................................................................................................................... 82
Modbus PDU (protocol data unit) .................................................................................................................... 82
Modbus function supported............................................................................................................................. 82
Time synchronization ....................................................................................................................................... 82
Events ............................................................................................................................................................... 83
Parameters ....................................................................................................................................................... 84
Address table.................................................................................................................................................... 85
3.2 Protocol IEC60870-5-103 ...................................................................................................................................... 98
General description .......................................................................................................................................... 98
Acronyms and Terms........................................................................................................................................ 98
Protocol data transfer ...................................................................................................................................... 98
Supported standard options and functions.................................................................................................... 100
8 Interoperability......................................................................................................................................................... 100
Parameters ..................................................................................................................................................... 107
Data table –Monitor direction....................................................................................................................... 108
Data table –Control direction ........................................................................................................................ 111
4Settings ........................................................................................................................................................................ 112
4.1 Introduction ........................................................................................................................................................ 113
4.2 Human machine interface (HMI) ........................................................................................................................ 113
User interface ................................................................................................................................................. 113
LCD.................................................................................................................................................................. 114
Menu overview............................................................................................................................................... 116
Submenus overview ....................................................................................................................................... 119
4.3 PC based graphical interface MiQen Setting Studio ........................................................................................... 130
Installation...................................................................................................................................................... 131
Using MiQen software.................................................................................................................................... 132
Content
USER MANUAL FPC 200 - 3/2017 9
5Mounting and commissioning .....................................................................................................................................148
5.1 Safety instructions...............................................................................................................................................149
5.2 Precautions .........................................................................................................................................................149
Device stored in its original packaging............................................................................................................149
Device installed in a cubicle ............................................................................................................................150
Working environment.....................................................................................................................................150
5.3 Equipment identification and unpacking ............................................................................................................151
Package specification......................................................................................................................................151
Device identification .......................................................................................................................................151
5.4 Device installation ...............................................................................................................................................152
Service conditions ...........................................................................................................................................152
Dimensions .....................................................................................................................................................152
Cut-out dimensions.........................................................................................................................................153
Assembly.........................................................................................................................................................154
Spacing............................................................................................................................................................155
Recommended external protection elements ................................................................................................155
5.5 Connection ..........................................................................................................................................................156
Grounding wire ...............................................................................................................................................157
Connection scheme ........................................................................................................................................158
Serial connection ............................................................................................................................................159
5.6 External module ..................................................................................................................................................160
EX 408 Temperature module ..........................................................................................................................160
5.7 Commissioning ....................................................................................................................................................162
Handling conditions ........................................................................................................................................162
Testing equipment required ...........................................................................................................................162
Device overall check .......................................................................................................................................162
Checking parameter and protection setting ...................................................................................................163
Start-up ...........................................................................................................................................................163
Hardware overview.........................................................................................................................................163
Protection validation ......................................................................................................................................166
6Technical data ..............................................................................................................................................................167
6.1 Type tests ............................................................................................................................................................168
6.2 Technical characteristics .....................................................................................................................................170
7Appendix A: Ordering code ..........................................................................................................................................173
8Appendix B: Analog inputs configuration ....................................................................................................................174
9Glossary........................................................................................................................................................................175
Introduction
10 USER MANUAL FPC 200 - 3/2017
1Introduction
The chapter introduces FPC 200 device. Provided information can help you to pick device type which covers specific needs
of your project.
1.1 Presentation ........................................................................................................................................................... 8
1.2 Selection table ........................................................................................................................................................ 9
1.3 Device description ................................................................................................................................................ 10
Introduction
USER MANUAL FPC 200 - 3/2017 11
1.1 Presentation
FPC 200 is a family of current and voltage numerical protection relays with easy to use interface meant for variety of
solutions in industry and power distribution.
Its robust design enables it to be placed in demanding industrial environments.
Setting can be done completely through user friendly Human Machine Interface (HMI) unit. Visual experience is enhanced
through PC based interface software MiQen featuring specially designed menus where electrical attributes of power
system are graphically and numerically displayed in real time.
Transferring settings between different devices is easily done thanks to front panel USB port. Same settings are
transferred from one device to another using USB stick which can also be used to save fault recordings, counters and
software updates.
FPC 200 is a member of NEO3000 Substation system and can be integrated to any other new or existing substation or
automation protection and control system.
Main features are:
-Robust design for industrial usage
-Fast and simple commissioning
-Fault and event recording
-Intuitive user interface
-Multiple communication capabilities
-Numerical and graphical MiQen software tool
-Easy data transfer using USB stick
-Low power consumption
Figure 1.1: FPC 200 protection relay.
Introduction
12 USER MANUAL FPC 200 - 3/2017
1.2 Selection table
Feeder
Busbar
Motor
Transformer
ANSI code
F1
F3
B2
B3
M1
M3
T1
T3
Current protections
Overcurrent DT/IDMT with Inrush restraint and Cold
Load Pick-up
50/51
4
4
4
4
4
4
Earth fault overcurrent DT/IDMT with Inrush restraint
and Cold Load Pick-up
50/51|N/G
4
4
4
4
4
4
Restricted earth-fault
64REF
2
2
2
Negative sequence overcurrent / unbalance
46
1
1
1
1
1
1
Phase undercurrent
37
1
1
Voltage protections
Phase-to-phase under voltage
27
2
2
Remanent under voltage
27R
1
1
Positive sequence under voltage
27D
2
2
Phase-to-phase overvoltage
59
2
2
Neutral voltage displacement/Residual overvoltage
59N
2
2
Over frequency
81H
2
2
Under frequency
81L
2
2
Rate of change (ROCOF)
81R
1
Power and machine protections and diagnostic
3 phase thermal overload (transformers)
49
Temperature monitoring (up to 8 sensors)
38/49T
Locked rotor, excessive starting time
48/51LR/14
Starts per hour
66
Thermostat / Buchholz switch
26/63
External trip
2
2
2
2
2
2
2
2
Automation and diagnostic
Circuit breaker control and monitoring
94/69
Circuit breaker failure
50BF/62BF
Trip circuit supervision (TCS)
74TC
Auto-reclosing
79
Lockout Relay
86LR/94
Cumulative breaking current
Metering
Phase current, RMS, THD, Harm., Residual c. 3I0
Earth current sensitive
Opt.
Opt.
Opt.
Opt.
Opt.
Opt.
Ph. & PPV voltages, RMS, THD, Harmonics
Frequency
Running hours
Communication protocols
Modbus
Optional
IEC 60870-5-103
Optional
Table 1: Selection table Opt. Optional,
included.
Introduction
USER MANUAL FPC 200 - 3/2017 13
1.3 Device description
Design of FPC 200 is modular. Base unit consists of housing, human machine interface (HMI), analog measurement card
(AMC) and six digital outputs (DO) with power supply (PS). AMC provides current or voltage measurements. Optional cards
extends the input/output and communication capabilities. Further extension is possible with external modules.
Base unit with maximum configuration includes:
Front panel with HMI and USB interface
rear panel with 10 digital inputs
8 digital outputs
2 serial communication ports
3 analog outputs
4 analog inputs
Connection configuration
Two connection configurations exist based on device type. Current measuring configuration is shown on Figure 1.2
whereas voltage version is shown on Figure 1.3.
Figure 1.2: Current measurements configuration.
Figure 1.3: Voltage measurements configuration.
Functionality
14 USER MANUAL FPC 200 - 3/2017
2Functionality
This chapter describes various functions of the FPC 200 device. It explains options of each function in maximum
configuration and provides information on how to determine the setting values and, if required, corresponding formulas.
The following information also allows you to specify which of the available functions to use.
2.1 Protections in general........................................................................................................................................... 15
2.2 Current based protections.................................................................................................................................... 20
2.3 Voltage based protections .................................................................................................................................... 32
2.4 Frequency based protections ............................................................................................................................... 42
2.5 Power and machine protections........................................................................................................................... 48
2.6 Automation and diagnostic................................................................................................................................... 60
2.7 User defined signals.............................................................................................................................................. 75
2.8 Disturbance recording .......................................................................................................................................... 76
2.9 Measurements...................................................................................................................................................... 78
2.10 Self-diagnostic....................................................................................................................................................... 80
3Communication ............................................................................................................................................................. 82
3.1 Modbus RTU ......................................................................................................................................................... 82
Functionality
USER MANUAL FPC 200 - 3/2017 15
2.1 Protections in general
Within this chapter the general theory of protection functions is described. For clear understanding several time
characteristics for different scenarios are presented.
Default values
Default values are presented as bold.
Example:
Parameter
Range
Pickup delay
0 … 5… 1000 ms
Minimum value of pickup delay is 0 ms, maximum
value is 1000 ms. Default value is set to 5ms.
Table 2 Example of default parameter setting.
Protection operation range
Fault is detected when monitored value exceeds the
chosen threshold (pickup value). At that point the
protection enters into protection operation range or
fault area. To prevent unwanted switching a hysteresis
characteristic is introduced. Drop-out value is set
relative to pickup value.
When the monitored value enters the protection
operating range the protections picks up. On the other
hand when the value falls below the operating range the
protection drops or resets.
Protection operation range is shown on Figure 2.1.
Pickup value
Drop-out value
Fault detection
Monitored value
Fault area
Figure 2.1: Protection operation range - fault area.
Example: Nominal current of protected element In_obj is
set to 300 A, pickup value is set to 1,1 In_obj and Drop-out
is 0,95 Ip. The protection will pick up when current
exceeds 330 A. It will drop out when the current drops
below 313,5 A.
Operational scenario is illustrated on Figure 2.2. Drop-
out delay prevents the timer of protection function to
reset in case the fault falls below the pickup value for a
short period of time. It is usually used when very long
time characteristics are used. In case the protection
trips, drop out delay is not accounted for and other
means of delaying trip signal are used.
Pickup signal
Fault detection
Trip signal
Pickup
delay
Trip delay
Drop-out
delay
Drop-out
delay
Figure 2.2: Pickup signal and Trip signal when fault duration is
shorter than trip delay.
2.1.2.1 Pickup logic
The pickup signal indicates that monitored value
exceeded the set value and indicates that a fault
occurred (Figure 2.2). The pickup delay is intended for
fault signalling stabilization to prevent the short-lived
disturbances in the measuring part of the system from
being reported as faults (Figure 2.4).
The pickup is set (Figure 2.3):
When a fault is detected and
Pickup delay confirmation time runs out and
There is no blocking
Fault
detection
Pickup
Blocking
Pickup
Delay Pickup
&
Figure 2.3: Pickup set logic.
Functionality
16 USER MANUAL FPC 200 - 3/2017
Pickup drops when:
Fault is not present anymore, the drop-out
delay runs out and the Trip signal has not set
yet or
fault is not present anymore and Trip signal is
already set or
a blocking occurs.
Pickup signal
Fault detection
Trip signal
Drop-out
delay
Pickup
delay
Pickup
delay
Trip
delay
Figure 2.4: Fault confirmation.
2.1.2.2 Trip logic
The Trip signal is intended for opening of circuit breaker,
which eliminates faulty element from power system.
Majority of faults have transient character and
disappear spontaneously. The duration of such faults is
relatively short. In order to avoid unnecessary opening
of circuit breaker the Trip signal can be delayed. Among
others the delaying of Trip signal may be used to ensure
selectivity along the power system network. The delay is
set with Trip delay parameter. In case the protection is
blocked the Trip signal will not set.
The Trip is set (Figure 2.5):
When a fault is detected and
when the pickup signal is stated and
trip delay time runs out and
no blocking is present.
Trip
Delay
&
Blocking
Pickup
Fault
detection
Trip
Figure 2.5: Trip set logic.
Trip signal drops:
when the pickup drops or Blocking appears
When the protection trips there are some particular
delays on detection and trip execution levels. Several
milliseconds can pass during transfer of the signal to
external output relay and forward to the circuit breaker
switch of the circuit. The compensation of lost time is
solved with default value.
2.1.2.3 Blocking
Function is blocked when any pickup Block input is set. It can be set through digital input port or it can be set internally in
combination with different functions. When the protection is blocked the pickup signal drops and pickup blocked signal is
stated. Consequently after the pickup signal drops the Trip delay timer resets. After the blocking is reset and if the fault is
still present the protection function starts again. Protection operation with blocking signal turned on for a certain amount
of time is shown on Figure 2.6.
Pickup
Pickup block
Fault
Pickup blocked
Pickup
delay
Pickup
delay
Trip
delay
Trip
Trip
delay
Figure 2.6: Protection operation with blocking signal turned on for a certain duration.
Functionality
USER MANUAL FPC 200 - 3/2017 17
Time characteristics
The main purpose of inverse time characteristics (IDMT
–Inverse Definite Minimum Time) is to enable shorter
time of protection trip when the fault current amplitude
is greater. At a set fault value the protection must trip in
time that can be read out from a characteristic. The
operation time depends on the measured current value
in accordance with standards IEC 60255-3 and IEEE C-
37112.
The available area of inverse time characteristic is
defined in a range between 1,1 and 20 Ip, where Ip
stands for pickup value. Amplitudes above 20 Iphave an
equal trip delay as the amplitude at 20 Ip. Amplitudes
from 1,1 Ipand lower have an equal trip delay as the
amplitude at 1,1 Ip.
The type of time characteristic can be chosen with the
mode parameter. It is necessary to set the pickup value
and IDMT coefficient parameters. Values are used with
all types of time characteristics. The IDMT coefficient
factor defines the time delay level. Lower values
indicate faster operation at equal fault values.
The fault current amplitude is not always constant and
can change during fault duration. For this reason the
algorithm dynamically integrates parts of time during
the fault according to particular characteristic and when
the sum reaches the switch off limit the protection trips.
0 1,0
drop
out 20 x Pickup
Trip
delay
Fault area
Fault
amplitude
1,1
Figure 2.7: Time inverse characteristic.
Name of curve
IEC Normal inverse
IEC Very inverse
IEC Extremely inverse
IEC Long time inverse
IEEE Moderately inverse
IEEE Very inverse
IEEE Extremely inverse
RI curve
Table 3 Time inverse curve types.
2.1.3.1 IEC characteristics
Equation 1 Time to trip for IEC inverse characteristics.
Name of characteristic
α
β
Normal inverse
0,02
0,14
Very inverse
1
13.5
Extremely inverse
2
80
Long time inverse
1
120
Table 4: Coefficients of IEC characteristics.
2.1.3.2 RI curve
Equation 2 Time to trip for RI inverse characteristics.
2.1.3.3 IEEE characteristics
Equation 3 Time to trip for IEEE inverse characteristics
equation.
Name of characteristic
α
β
Moderately inverse
0,02
0,114
0,0515
Very inverse
2
0,491
19,61
Extremely inverse
2
0,1217
28,2
Table 5: Coefficients of IEEE characteristics.
T …
protection trip time
k …
IDMT coefficient factor
α, β, …
Coefficient values
I…
Fault current amplitude
…
set limit of fault range, pickup value
Functionality
18 USER MANUAL FPC 200 - 3/2017
2.1.3.4 Graphs of inverse characteristics
Graphs below represent time to trip depending on current and user defined IDMT setting for each of the inverse time
characteristics.
Figure 8 IEC Normal inverse characteristics.
Figure 9 IEC Very inverse characteristics.
Figure 10IEC Extremely inverse characteristics.
Figure 11 IEC Long time inverse characteristics.
1.1 2 3 4 5 6 7 8 9 10
1
10
100
1000
1500 IEC Normal inverse
I / In
t [s]
0.05
IDMT
0.1
IDMT
0.2
IDMT
0.3
IDMT
0.4
IDMT
0.6
IDMT
0.8
IDMT
1
IDMT
1.1 2 3 4 5 6 7 8 9 10
0.1
1
10
100
1000
1500 IEC Very inverse
I / In
t [s]
0.05
IDMT
0.1
IDMT
0.2
IDMT
0.3
IDMT
0.4
IDMT
0.6
IDMT
0.8
IDMT
1
IDMT
1.1 2 3 4 5 6 7 8 9 10
0.1
1
10
100
1000
1500 IEC Extremely inverse
I / In
t [s]
0.05
IDMT
0.1
IDMT
0.2
IDMT
0.3
IDMT
0.4
IDMT
0.6
IDMT
0.8
IDMT
1
IDMT
1.1 2 3 4 5 6 7 8 9 10
1
10
100
1000
1500 IEC Long time inverse
I / In
t [s]
0.05
IDMT
0.1
IDMT
0.2
IDMT
0.3
IDMT
0.4
IDMT
0.6
IDMT
0.8
IDMT
1
IDMT
Functionality
USER MANUAL FPC 200 - 3/2017 19
Figure 12 IEEE moderately inverse characteristics.
Figure 13 IEEE Extremely inverse characteristics.
Figure 14 IEEE Very inverse characteristics.
Figure 15 RI inverse time characteristics.
1.1 2 3 4 5 6 7 8 9 10
0.1
1
10
100
150 IEEE MI
I / In
t [s]
0.05
IDMT
0.1
IDMT
0.2
IDMT
0.3
IDMT
0.4
IDMT
0.6
IDMT
0.8
IDMT
1
IDMT
1.1 2 3 4 5 6 7 8 9 10
0.1
1
10
100
150 IEEE EI
I / In
t [s]
0.05
IDMT
0.1
IDMT
0.2
IDMT
0.3
IDMT
0.4
IDMT
0.6
IDMT
0.8
IDMT
1
IDMT
1.1 2 3 4 5 6 7 8 9 10
0.1
1
10
100
150 IEEE VI
I / In
t [s]
0.05
IDMT
0.1
IDMT
0.2
IDMT
0.3
IDMT
0.4
IDMT
0.6
IDMT
0.8
IDMT
1
IDMT
1.1 2 3 4 5 6 7 8 9 10
1
10
100
150 RI
I / In
t [s]
0.05
IDMT
0.1
IDMT
0.2
IDMT
0.3
IDMT
0.4
IDMT
0.6
IDMT
0.8
IDMT
1
IDMT
Functionality
20 USER MANUAL FPC 200 - 3/2017
2.2 Current based protections
Overcurrent protection - ANSI code 50/51
Overcurrent protection is one of the basic functions of FPC 200 numerical relays. It protects the feeder or other elements
of the power system from overcurrent when fault occurs. It comprises of various time-delayed characteristics. Protective
function includes Inrush restraint [2.2.5] and Cold load pickup (CLP) protection.
2.2.1.1 Functionality
Overcurrent protection is used as non-directional time
delayed overcurrent and short-circuit protection. It picks
up when current in one, two or three phases exceeds
the set threshold. The function can be enabled or
disabled through corresponding menu. The trip time
characteristics can be selected to be Instantaneous,
definite time (DT) or inverse definite minimum time
(IDMT). When instantaneous operation mode is selected
the trip signal is stated as the DT characteristic. The
settings of this function are applied to each of the three
phases to produce pickup and trip signals per each
phase.
Several overcurrent protection instances with different
settings can run independently at the same time.
The selection of pickup value, pickup delay as well as
drop-out ratio and drop-out delay helps the user to fine
tune the protection according to the project
specifications.
50/51 Over current
Mode:
Enable:
IDMT coeficient: 0,02
ON
Pickup value: 1,2xIn
A
Trip delay: 0,4s
Ext. inverse
1A 1B 2A 2B 3A 3B 4A
Figure 2.16: Overcurrent protection setting.
2.2.1.2 Measurements
The value of each phase current is acquired through
separate input current transformer. The measured
phase currents are compared with the set pickup value.
2.2.1.3 Delays
Function includes following delays explained in Chapter
2.1:
Pickup delay
Trip delay
Drop-out delay
2.2.1.4 Cold load pickup
A temporary increased starting current can appear
when energizing feeders with loads that had a long zero
voltage period (e.g. air-conditioning systems, heating
installations, motors...). Its value can be up to several
times higher than the nominal current. To avoid
unwanted protection operation the pickup limit has to
be raised temporarily. The function is set with
parameter Enable. It triggers through the activation of
corresponding digital input or when current raises
above
5 % of In_obj in at least one phase after certain amount
of time has passed.
The dynamic pickup value changeover is common to all
overcurrent elements. With inverse characteristics, the
CLP influences only the fault detection limit, whereas
the time calculation of the selected inverse
characteristic is not affected.
Pickup value
Drop-out value
CLP activated
Monitored value
Fault area
Fault detection
Figure 2.17: Operation with CLP activated for a shorter than
fault time duration.
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