Testing of Protection Relay: Typhoon HIL, Scada Modeling

Krutika Gite
VJTI Mumbai, India

Abstract— This article describes some methods, used in their reliable service, all of these relays require a regular
protective relay testing. Protective relay is a very important care and maintenance like preventive medical checkups by
part of the energy system. Its purpose is to find out the fault human. They also required to be tested frequen. Electrome-
and to switch off a circuit breaker in order to prevent the
non-affected part of the power network. Modeling the energy chanical Fig. 1b. Solid State Relays. Digital Relay Intervals
system is needed not only to test and evaluate the action of for their functional testing. The details of maintenance and
the protective relays but for personnel training in conditions functional testing to be done on various types of relays will
similar to these in real networks as well. Because of that the be discussed in subsequent sections. Table I summarize the
model must be more realistic and has to perform faults in field maintenance and tests to be done on various relays with
real time. A various of parameters of the signals must be
simulated to perform situations, occur in real networks. The their testing frequency. TABLE I FIELD MAINTENANCE
paper shows some methods for protective relays static and AND TESTS Maintenance or Tests to be done Frequency
dynamic testing. These methods require generating signals with Electromechanical relays calibration and functional testing
variable parameters for every different application. The paper Once in every 1 year in clean environment or once in every 6
describes some signals used in research and manufacturing months in polluted area. [1] Solid-state relays calibration and
of relay equipment and for field tests of protective relays
too. Today’s Protective relays are the vital components in the functional testing Once in every 2 years [2] Microprocessor1
electrical power system. These relays monitor the set electrical (digital) relays functional testing. Once in every 4 years [3]
parameters like voltage, current etc. and initiate action to isolate
the faulty component from the electrical network so that the
balance healthy system will continue to extend the services to
II. MAINTENANCE OF RELAYS
its customers. These important elements in the electrical system
require regular maintenance and field testing so as to ensure Like any other machines relays also requires regular
their availability in the system. This paper intends to overview maintenance on them. They are discussed here with cate-
the type of relays and their field maintenance requirements for gory wise. 1.Electro-Mechanical relays: These are the first
their reliable service. Connecting the physical protection relays generation relays having so many moving mechanical parts
to our real-time replica of the microgrid on the signal, power, to be maintained as follows:- i. Cleaning of relay case,
and communication level. Using Typhoon API and Python
scripting, execute complex scenarios and fully automate our terminals, and all the internals. ii. Check the tightness of
testing processes. The same environment enables you to conduct all the wire connections and parts. iii. Lubrication of all
a sensitivity analysis of the whole system in real-time. the moving parts. iv. Check for the free rotation of disc
Index Terms— Protective Relay, Field Maintenance,Current in case of IDMT (Inverse Definite Minimum Time) relays.
Transformer(CT), Potential Transformer(PT), TyphoonHIL, v. Check the contact gap with feeder gauge. vi. Check for
Scada modeling
any dents on the disc and repair/replace the worn out disc,
other hardware like washers, springs and screws. vii. Visual
I. INTRODUCTION
checking for intervals healthiness. 2. Solid State Relays:
As power grids get bigger and carry more power, the These are of second generation which generally do not have
need for quick, reliable disconnection when faults occur any mechanical/moving components except contacts. These
becomes more and more urgent. The purpose of protective relays require some maintenance as follows:- i. Cleaning of
relay equipment is to sense fault states and trip circuit relay case, terminals, and all the internals. ii. Check the
breakers. If a fault is not corrected early, personal injuries tightness of all the wire connections and parts. iii. Check
and serious damage can occur. Disconnection must take for overheated electronic components like Thyristors, heat
place selectively, i.e. it must be limited to the faulty part of sinks, resistors, inductors, capacitors etc. iv. Check for black
the power grid. This is why the protective relay equipment spots on Printed Circuit Board (PCB). v. Visual checking
must be able to distinguish between permissible heavy load for internal healthiness. 3. Digital relays: These are the
conditions and hazardous operational disturbances. To avoid latest third generation relays which require basic minimum
unjustifiable interruptions, the protective relay equipment maintenance .They do not have any moving or mechanical
must not react to disturbances beneath a specified level called parts, hence they are more reliable but the dust is the
the pick-up value. Protection is the main diagnosis system main culprit for their mal operation. Following minimum
in the electrical power network which will continuously maintenance is required for these relays:- i. Cleaning of
monitor the power network and detects the faults as and relay case, terminals, and all the internals. ii. Check the
when they occurs simultaneously they will isolate the faulty tightness of all the wire connections and parts. iii. Check for
equipment from the network and protects the network.For overheated electronic and microprocessor based components.
iv. Check for black spots on Printed Circuit Board(PCB). v. PC front port communication for convenient relay settings •
Visual inspection for internal healthiness. User friendly local operation with key pad • Large Liquid
crystal display (20X4) with backlight • Password Protection
III. DESIRABLE PROPERTIES OF PROTECTIVE • If Special connector is removed from the back side of the
RELAYS CT Terminal, CT secondary terminal will be automatically
The desirable attributes are as follows [4]: i. shorted. • Measurement of Voltage, current magnitude, sym-
Dependability- It means relay trips only when it is metrical components, Real, Reactive and Apparent Power,
expected to trip Dependability = Number of correct trips Power factor and frequency. Software Support: • Online/
Number of desired trips This can be improved by increasing offline Setting Editor. • Programmable scheme logic Editor.
the sensitivity of the protection system. ii. Sensitivity: • Settings upload / download. • Online Measurement. •
The relay shall be able to detect even the smallest faulty Disturbance analysis. • Relay assistant for testing relay at
protected parameter. iii. Security: It is nothing but the relay site.
not acting when it is not desired to act. Security = Number
of correct trips Total Number of trips This can be improved V. A PPLICATION OF RELAY ADR245B
by improving the selectivity of the protection system. iv.
Selectivity: It is the ability to discriminate between different ADR245B numerical multifunction relay is designed for
faults v. Reliability: It is the performance of the relay Transmission line protection, ADR245B
consistently. Reliability= Number of correct trips Number Underground cable feeder protection, Machine protection,
of desired trips+Number of incorrect trips and shunt capacitor bank protection applications. Relay de-
signed with fast and selective tripping ensures the stability
IV. RELAY ADR245B and availability of electrical power system. ADR245B relay
ASHIDA has designed economical reliable Multifunc- can be applied for protection, control monitoring of radial
tion ADR245B Protection Control System. The simple and ring main feeder to achieve sensitivity and selectivity on
and compact construction of ADITYA series. ADR245B phase and ground faults. The core functionality of ADR245B
relay provides integrated Protection, Control and Monitoring relay is equipped with multi function feederprotection. The
functions for Over head Transmission Lines, Underground relay provides Directional and Non Directional phase and
cables, and Distributed Feeders. Key Protection Control ground over current protection with multiple settings (four
Functions: • Four Independent Settings Groups. • Directional stages for phase over current and three stages for ground
/ Non Directional Phase Ground Over Current Function over current) for various power system applications and
(50/51/51N/51/67/67N). • Four Independent Stages for Di- wide range of protection settings. The relay is equipped
rectional / Non Directional Phase Over Current Protection. with digital filter algorithms, which provides the rejection of
• Three Stages of Directional / Non Directional Internally higher harmonics DC offset. Selectable IEC/IEEE inverse
Derived (3I0¿) / Externally Measured (IE¿) Ground Over time curves with directional/non directional over current
Current Protection. • Inverse time Over Current Protec- protection will be provide greater selectivity, flexibility and
tion (IEC IEEE curves according to IEC60255). • High sensitivity to users for better relay coordinations. ADR245B
Impedance Restricted Earth Fault Protection (64R). • Ther- relay provides inverse time over current characteristic for
mal Overload Protection (49) • Inverse Definite time Positive phase and ground over current elements. Each stages of phase
Negative Phase Sequence Over Current Protection (46). • and ground over current elements are independently settable
Broken Conductor Protection (46BC) • Positive Negative with inverse time or definite time characteristic Directional
Phase Sequence Over Voltage Protection (47). • Under and element of relay will decide faults in forward/reverse direc-
Over Voltage Protections (27 /59). • Externally Measured tion by voltage current flows on over head transmission line
(VN¿) / Internally Derived (3Vo¿) Residual Over Voltage / underground cable during faults. RCA/MTA setting range
Protection (59N). • Frequency Protection (81) • Rate of of relay will provide flexibility to user to set directional
change of Frequency (81R) (Optional) • Fault Locator (21FL) angles based on power system parameters. Operating time
(Optional) • Sync Check (25) (Optional) • SOTF (Optional) of directional element shall be settable instantaneous or with
• Multi shots (4-shots) Auto-reclosing function. • Breaker definite inverse time delay.ADR245B relay provides three
Failure detection (50BF) • VT and CT supervision function stages of definite time/inverse time internally derived zero
• Trip circuit supervision function • Programmable Inputs sequence over current (3I0¿) protection to detect asymmet-
Outputs • CB Close / Trip from HMI • Programmable Target rical faults in electrical network. It can be applied to over
LEDs for indications with dual colours • Self Supervision of head transmission line, underground cable, and feeder. The
relay • Metering function • Disturbance Recording (10 nos.) ground current (3I0¿) can be calculated from three line
• Event Recording (512 nos.) • Fault Recording on HMI currents.ADR245B relay provides three stages of externally
display (10 nos.) • Non-Volatile memory • Fully commu- ground over current protection. ADR245B relay measures
nicable with IEC standard open protocol IEC60870-5-103, ground fault current through neutral CT input. Externally
MODBUS, IEC104 IEC 61850. • SCADA communication ground CT input can also be applied for high impedance
• Single / Dual Ethernet ports (RJ45 / FO), RS485 port • restricted earth fault protection or for sensitive ground fault
PRP/HSR option for fast redundant network (Optional). • protection through CBCT.
 VI. P ROTECTION Frequency protection function provides either under or
over frequency protection of line/feeder/machine. ADR245B
Thermal overload Protection (49):
relay provides six independent stages with definite time delay
ADR245B relay provides thermal over load protection of
characteristic. Stages can be set in a under or over frequency
transformer against over load conditions. Relay estimates
mode. Protection function can also be used for load shedding
thermal content and initiate alarm tripping if the thermal
scheme.
contents are higher than the preset value. Trip time of relay
Rate of change of frequency - 81R (df/dt):
follows the thermal time constant value set in relay.
This Protection function is used for quick disconnection of
Sequence Over Current Protection (50P/46):
a generator or loadshedding control. Based on the calculation
ADR245B provides sequence over current against unbal-
of the frequency variation, it is insensitive to transient voltage
ance faults/condition or high impedance faults over trans-
disturbances and therefore more stable than a phase-shift
mission line/under ground cable or over load condition.
protection function.
Sequence over current function is provided in two modes;
Positive sequence and Negative sequence over current func- Synch-check (25):
tion. User can select the mode based on their application This function helps to monitor the voltages on both sides
and requirement.The negative phase sequence over current of a circuit breaker and determines that proper phase angle
element can be programmed as IDMT or definite time and voltage exist prior to allowing the breaker to be closed.
characteristic. ADR245B relay provides ten selectable IEC Fault locator (21FL):
IEEE inverse curves for each stage. Protection can also be The fault locator (FL) is designed to estimate the distance
applied in a condition when there is a very high resistive of the fault in the feeder using fundamental phasor magnitude
ground fault and ground element may not sense the fault of the voltage and current signals.
current. Breaker Failure detection (50BF):
Broken Conductor Protection (46BC): If the fault current is not interrupted even after a expiry
ADR245B is equipped with Broken conductor detection of time delay, circuit breaker failures shall be detected, and
protection. Broken conductor condition can be detected by should execute trip command to upstream circuit breaker.
the ratio of Negative sequence current to Positive sequence ADR245B relay incorporates circuit breaker failure protec-
current (I2/I1). Protection provides higher sensitivity on High tion to detect failure of tripping command execution due to
resistive fault. mechanical or electrical problems in circuit breaker.
I0/I1 detection:
ADR245B provide independent I0/I1 function for sensitive VII. T YPHOON HIL SCADA
ground fault detection. Relay measure the ratio of zero to Typhoon Script Editor enables you to build and execute
positive sequence current precisely. test libraries to exhaustively test all aspects of a controller.
Over Under Voltage Protections (59/27): ADR245B relay Program test sequences under a spectrum of operating con-
provides independent phase over and under voltage protec- ditions, including faults. For grid connected converters, test
tions with definite time delay range. Relay also provides dynamic grid support, i.e. low voltage ride through, active
the positive sequence over voltage protection with definite and reactive power injection, protection etc. Use the library
time characteristic option. Protection functions can be pro- of test scripts to test in accordance with dynamic grid support
grammed for alarm signal or trip signal. standards such as German BDEW or American UL 1741
Residual Over Voltage Protections (59N): SA. In drives applications, program various drive cycles
ADR245B relay provides zero sequence / residual over and test fault responses under both internal and external
voltage protection with definite time delay range. Protection faults. For example, inject short and open circuit faults,
can be achieved by externally measured residual voltage switch faults, and test against parameter variations. Define
through open delta VT or the zero sequence voltage inter- performance envelopes and verify the system compliance.
nally calculated from three phases. Typhoon API comprises: HIL Control Panel API, Schematic
Negative Phase Sequence Over Voltage Protections (47): Editor API, Texas Instruments DSP Control Panel API, and
ADR245B relay provides positive/negative sequence over Test Executor. HIL Control Panel API provides an interface
voltage protections with definite time delay range. It pro- with the target HIL and enables control of the simulation
vides protection against high resistive faults and unbalanced process and all functions available through Control Panel.
loading condition Schematic Editor API provides programmatic interface to
Directional Power Protection (32): manipulate existing schematic diagrams. It enables chang-
The directional power protection is designed for protection ing circuit parameters, compiling a circuit, setting target
against reverse power mode and over / under load protection hardware platform, time step, simulation method etc. Texas
in forward power mode. It can also be settable as a active Instruments DSP Control Panel API provides programmatic
/ reactive power mode. ADR245B provides four elements interface to control TI docking station and change controller
for power protection with independent definite time delay parameters. Test Executor Test enables running one or more
characteristic. python scripts and generates html report files with test
Frequency Protection (81O/U): results. Supervisory control and data acquisition (SCADA)
is a control system architecture comprising computers, net- ACKNOWLEDGE
worked data communications and graphical user interfaces The authors of the paper would like to acknowledge the
(GUI) for high-level process supervisory management, while support of Dr. N. M. Singh associated with Control and De-
also comprising other peripheral devices like programmable cision Research Center (CDRC), EED, VJTI, Mumbai, India,
logic controllers (PLC) and discrete proportional-integral- for providing guidance and rigorous technical discussion.
derivative (PID) controllers to interface with process plant or The authors also would like to extend gratitude to the Dr. S.
machinery. The use of SCADA has been considered also for R. Wagh for providing support and help in the preparation
management and operations of project-driven-process in con- of manuscript.
struction.The operator interfaces which enable monitoring
and the issuing of process commands, like controller set point R EFERENCES
changes, are handled through the SCADA computer system. www.researchgate.net/publication/340848870R eviewo nF ieldT estingo fP rote
The subordinated operations, e.g. the real-time control logic ieeexplore.ieee.org/document/931069
or controller calculations, are performed by networked mod-
ules connected to the field sensors and actuators.
The SCADA concept was developed to be a universal
means of remote-access to a variety of local control modules,
which could be from different manufacturers and allowing
access through standard automation protocols. In practice,
large SCADA systems have grown to become very similar to
distributed control systems in function, while using multiple
means of interfacing with the plant. They can control large-
scale processes that can include multiple sites, and work over
large distances as well as small distance. It is one of the
most commonly-used types of industrial control systems, in
spite of concerns about SCADA systems being vulnerable
to cyberwarfare/cyberterrorism attacks.All functions, such as
modeling in Schematic Editor, controlling and interacting
with the emulation in HIL SCADA, acquiring data with
scope and capture, and automating testing through Typhoon
API and Python scripts, work exactly as if you were using
a single HIL.
The ASCADA-SAS (ASHIDA SCADA Software Sys-
tems) is Windows operating system based, extremely user-
friendly Software and works in a point-n-click environment.
The ASCADA - SAS Software interrogates SCADA mod-
ules installed on individual bays/post. All such information
collected from various modules is then processed, recorded
presented to the user in form of colored mimic diagrams,
event lists, alarm lists, graphs, summary screens annunci-
ation windows etc. These can be further conferred as per
user requirements for customized audio alarms, etc. In this
mimic display screen, monitored component can be selected
and operated with a simple point-n-click procedure. The user
has an option to control individual bays based on this data.
Multiple such sub-stations can be monitored from a single
location. The recorded data is used to generate reports like
history event, feeder logs, energy audits, interruption, outage
or tripping reports, history graphs and other analytical reports
as per user requirements. Any of these can be exported to
all popular word processing spread sheet formats.
We connected the output of the HIL model to the amplifier
because output voltage of the HIL model was nearly about
5 volts. We used three amplifiers for 3 different phases of
voltage and current. The minimum requirement of the relay
was nearly 60 to 70 volts.Analyse the over current, over
voltage, under current, undervoltage fault by passing the
current and voltage through primary CT PT.