DESIGN, IMPLEMENTATION AND EVALUATION OF A
PROTECTION SYSTEM MONITORING SCHEME
A Project
Presented to the faculty of the Department of Electrical and Electronic Engineering
California State University, Sacramento
Submitted in partial satisfaction of
the requirements for the degree of
MASTER OF SCIENCE
In
Electrical and Electronic Engineering
by
Selvin LoweRodriguez
Chris Ridley
SUMMER
2013
© 2013
Selvin LoweRodriguez
Chris Ridley
ALL RIGHTS RESERVED
ii
DESIGN, IMPLEMENTATION AND EVALUATION OF A
PROTECTION SYSTEM MONITORING SCHEME
A Project
by
Selvin LoweRodriguez
Chris Ridley
Approved by:
__________________________________, Committee Chair
Turan Gonen
__________________________________, Second Reader
Salah Yousif
____________________________
Date
iii
Student: Selvin LoweRodriguez
Chris Ridley
I certify that these students have met the requirements for format contained in the
University format manual, and that this project is suitable for shelving in the Library and
credit is to be awarded for the project.
__________________________, Graduate Coordinator
Preetham Kumar
Department of Electrical and Electronic Engineering
iv
___________________
Date
Abstract
of
DESIGN, IMPLEMENTATION AND EVALUATION OF A
PROTECTION SYSTEM MONITORING SCHEME
by
Selvin LoweRodriguez
Chris Ridley
Statement of Problem
NERC Standard PRC-005 outlines the maintenance and testing requirements for transmission
and generator protection systems. The requirements are aimed at enhancing the reliability of
the protection system by enforcing the performance and documentation of all maintenance
and testing tasks. Such tasks are usually time consuming and in many cases can render
generation and transmission systems inoperable for extended periods of time.
This project is aimed at the design, implementation and evaluation of an automated
protection system monitoring (PSM) scheme. The system will perform checks on all relays,
current and voltage transformers associated with generation system protection during normal
steady state operation. The performance of each instrument transformer will be evaluated
based on readings from adjacent devices in the system as well as historic data. The protection
system includes generator, cable and generator step-up (GSU) transformer microprocessor
(µP) relays. Data from all relays will be collected and analyzed via a real time automation
controller (RTAC). The RTAC will evaluate the condition of all relays as well as associated
v
voltage and current transformers to provide a report that can be used to meet PRC-005 testing
requirements and decrease system scheduled and unscheduled down time.
Sources of Data
IEC 61131-3-2013
IEEE C57.13.1-2006
NERC PRC-005-2-2013
Conclusions Reached
Protection system monitoring can be accomplished utilizing up to date intelligent
electronic devices without the use of phasor measurement units. The importance of
protection system monitoring schemes is valuable ensuring power systems remain in
service with less likelihood of inadvertent operations due to preventable component
failures.
_______________________, Committee Chair
Turan Gonen
_______________________
Date
vi
TABLE OF CONTENTS
Page
List of Tables .............................................................................................................. ix
List of Figures ............................................................................................................... x
Chapter
1. INTRODUCTION ................................................................................................. 1
2. LITERATURE SURVEY ....................................................................................... 3
2.1 Protection System Overview....................................................................... 3
2.2 NERC PRC-005-2 Requirements ............................................................... 4
2.3 Real Time Automation Controller Application .......................................... 5
2.4 Current Transformer Characteristics........................................................... 6
3. MATHEMATICAL MODEL ................................................................................. 8
3.1 Introduction ................................................................................................. 8
3.2 Logic Programming .................................................................................... 9
3.2.1 Devices ............................................................................................. 10
3.2.2 Global Variables .............................................................................. 10
3.2.3 CT Test Function Block ................................................................... 10
3.2.4 Validation Program .......................................................................... 11
3.2.5 Tag Processor ................................................................................... 11
3.3 Reliability Impact of Monitoring System ................................................. 12
4. APPLICATION OF MATHEMATICAL MODEL.............................................. 17
4.1 CT Metering Performance Evaluation ...................................................... 17
vii
4.2 Implementation of Monitoring System ..................................................... 20
4.3 Performance Evaluation of PSM .............................................................. 21
5. CONCLUSION ..................................................................................................... 23
Appendix A. Protection and Communications Single Line Diagram ........................ 24
Appendix B. PSM Logic Diagram ............................................................................. 26
Appendix C. PSM Settings and Programming Summary .......................................... 31
References ................................................................................................................... 46
viii
LIST OF TABLES
Tables
1.
Page
Table 3.1 Inadvertent Opening Probabilities .................................................. 16
ix
LIST OF FIGURES
Figures
Page
1.
Figure 2.1 Basic CT Rating Calculation Example ............................................ 6
2.
Figure 3.1 Device Integration Diagram ............................................................ 9
3.
Figure 3.2 Basic Block Diagram for Protection System Reliability Studies .. 12
4.
Figure 3.3 Hyatt Power Plant Protection System Block Diagram .................. 13
5.
Figure 3.4 Protection System Event Tree ....................................................... 14
6.
Figure 4.1 RTAC Program Layout ................................................................. 17
7.
Figure 4.2 Current Transformer Performance Evaluation .............................. 19
8.
Figure 4.3 Current Transformer Performance Evaluation with Steady State
Permissive ....................................................................................................... 22
x
1
CHAPTER 1
INTRODUCTION
The continuous increase in demand placed in the bulk power system calls for the
implementation of maintenance and monitoring systems that increase the overall
reliability of such stressed network. Great emphasis is placed on protection system
maintenance and testing and is enforced by the North American Electric Reliability
Corporation (NERC) via standard PRC-005-2. The two aspects of protection system
reliability are defined in IEEE Standard C37.2 to be dependability and security [1].
Dependable operation refers to the ability of a system to operate correctly when required
per the intent of its design. Security refers to the certainty that a system will not operate
erroneously (misoperation). Protection system monitoring plays an important role in
overall as it prevents conditions protection system misoperation or failure. Such
conditions may lead to extended power outages and/or equipment damage.
In the era of the electromechanical (EM) relay, the protection system was regarded as a
silent sentinel, a system that only reports its condition when a fault or adverse system
condition exists. Today, the microprocessor relay has taken the place of EM and its
predecessor the solid-state relay. The extended capabilities of the µP relay range from
multiple devices in a single package through programmable logic, to the availability of
various communications protocols.
2
This project focuses on the integration of several microprocessor relays, each performing
an individual protective role for a pump/generating unit to include generator step-up
transformer (GSU) and cable up to a main high voltage (HV) bus. Protection system
monitoring (PSM) will provide status and report via supervisory control and data
acquisition (SCADA) to a remote computer running a human-machine interface (HMI)
program. While many devices are available for purpose of protection system integration,
this paper will focus in the use of Schweitzer Engineering Laboratories (SEL) SEL-3530
real-time automation controller (RTAC) for data collection and validation of current
transformer (CT) circuits. I this project, the process of validating current transformer
measurements will be introduced, documented and implemented. A similar procedure can
be utilized to validate potential transformers (PT) s but will not be presented. The
procedure for validating relay settings will be discussed without implementation due to
lack of resources and equipment capabilities.
3
CHAPTER 2
LITERATURE SURVEY
2.1 Protection System Overview
The power system protection system is regarded as unnecessary during normal operating
conditions. The term “Normal” is used in theory to identify the ideal conditions for which
a system is engineered. Over time these conditions may deviate based on changes in load,
changes in generation or abnormal conditions. It is during these abnormal conditions that
the protection system becomes extremely crucial in order to prevent such inadequate
performance or minimize outage time.
The modern protection system is comprised of instrument transformers, protective relays,
communication channels, breakers, and batteries. Later in this paper and for the purpose
of reliability analysis, these five components are regrouped into four categories or blocks.
When protection system failure is of concern, redundant practices aid in increasing
reliability. Inadvertent operation, in the other hand, is undesirable since redundancy
provides no protection against such action.
In modern protective system installations, inadvertent operation is commonly caused by
human error. When equipment is the cause of misoperation, a monitoring system can aid
in detecting unusual conditions. The article “Case Study in Improving Protection System
Reliability With Automatic NERC PRC-005 Inspection, Testing, Reporting, and
4
Auditing” discusses the event in which damaged wiring to a current transformer (CT)
caused several inadvertent operations. Damage to the specific circuitry could have been
detected by simple metering and comparison of downstream or upstream CTs.
Protection system maintenance and monitoring plays an essential role in maintaining
continuity of service and ensuring the protection system is available and ready to perform
during faults and other abnormal conditions. When properly scheduled, maintenance
practices yield little impact to power system performance. In the age of µP relays,
continuous monitoring is achieved via system integration and the scheduled maintenance
cycle elongated. Continuous monitoring not only aids in scheduled maintenance but also
helps detect abnormal conditions within the protection system.
2.2 NERC PRC-005-2 Requirements
The North American Electric Reliability Corporation (NERC) establishes and enforces
standards to protect the bulk electric system. One of these standards is PRC-005-2
(Protection System Maintenance). The purpose of PRC-005-2 is to require maintenance
programs of all Protection Systems with a critical impact to the bulk electric system.
Included in these required maintenance programs are the following tests: battery, relay
calibration, associated communications, and CT and PT tests. For the purpose of this
project, the focus will be the CT and PT tests. The required test intervals depend on the
device tested. The purpose of these intervals is to improve the reliability of the protection
system by detecting any failures, and fixing them, before a fault occurs. Real-Time
5
Automation Controller (RTAC) provides the ability to monitor a power system by
interfacing with an existing SEL microprocessor relay. This system monitoring meets the
requirements of the PRC-005-2 CT and PT tests. In addition, this RTAC increases the
reliability of the protection system because the CTs and PTs are tested continuously,
rather than the minimum interval requirement of every five years.
2.3 Real Time Automation Controller Application
System integration provides the means of utilizing the capabilities of each intelligent
electronic device (IED) to ensure system reliability is increased and maintained.
Programable logic controllers (PLCs) provide a base level of integration and are largely
used to automate electromechanical systems. They usually consist of inputs, outputs and
a programming environment based on contacts and coils called ladder logic.
Programmable automation controllers (PAC) s add a level of flexibility by incorporating
advanced programming languages such as C, C++ and IEC 61131 amongst others.
The SEL-3530 RTAC allows for advanced integration and concentration of data via the
use of industry standard programming language and over a wide variety of protocols. The
RTAC programming environment is based on IEC 61131 standard for programmable
controllers with user-friendly interface that allows the use of IEC 61131-3 operators as
well as proprietary extending functions. The protocols include industry standard DNP3,
Modbus, IEC C37.118 Synchrophasors, FTP/Telnet and SEL proprietary
communications.
6
2.4 Current Transformer Characteristics
CTs are a critical component of the protection scheme. Without a valid CT input to the
relay, the protection system will fail on every fault. The main CT characteristics are the
ratio (or tap for multi-ratio CTs), polarity and CT rating. The most common reasons for
an invalid CT input to the protective relay are loose connections or CT saturation. Loose
connections can be found during a visual inspection, CT saturation requires
measurements and proper CT rating selection when designing the protection scheme. See
Figure 2.1 for CT rating calculation example:
7000/5
Fault
ZLEAD
0.4Ω
ZLEAD
0.4Ω
Fault Data:
IF = 26.5kAϕ-G
X/R = 13.5
ZRELAY
0.15Ω
Figure 2.1 Basic CT Rating Calculation Example
The equations to calculate the CT Rating are,
X
(1 + R) × IF × ZB ≤ VSTD
(2.1)
VSTD = CT Standard Voltage Rating = 20 × IN × ZSTD
(2.2)
From equation (1) and (2),
7
X
𝐼
𝑍𝐵
(1 + R) × I𝐹 × Z
N
STD
≤ 20
(2.3)
Where,
IN = CT Nominal Current
ZSTD = Standard Burden (C100 = 1Ω, C200 = 2Ω…at 60°)
IF = Max Fault in per unit of CT secondary nominal current
ZB = Burden in per unit of standard
Results from C100 (ZSTD = 1Ω) are,
26.5kA
0.4Ω + 0.4Ω + 0.15Ω
(1 + 13.5) × (
)×(
) = 52.15 which is not ≤ 20
7kA
1Ω
Results from C400 (ZSTD = 4Ω) are,
26.5kA
0.4Ω + 0.4Ω + 0.15Ω
(1 + 13.5) × (
)×(
) = 13.04 ≤ 20
7kA
4Ω
Therefore, the CT Rating selected is C400 to avoid CT saturation in a faulted condition.
8
CHAPTER 3
MATHEMATICAL MODEL
3.1 Introduction
Protection system integration provides users and operators the ability to communicate
with remote devices to gather data or provide control capabilities. While this project will
not contemplate the control capabilities of system integration, the goal is to utilize the
protective devices to perform tasks that would otherwise be performed by maintenance
personnel requiring system outages and additional testing equipment. The system can
then accessed locally or remotely via direct or network communications.
The system to be integrated consists of two SEL-300G generator relays, one SEL-387-6
current differential and overcurrent relay, one SEL-387E current differential and voltage
relay, and one SEL-311L line current differential protection and automation system.
Appendix A illustrates the single line diagram of the protection system for each of the
units at California Department of Water Resources (CDWR) Hyatt Power Plant. Figure
3.1 illustrates the high-level diagram of the devices to be integrated. While relay 11CA
and 11CB provide differential protection of the HV cable between the GSU and the HV
bus, only 11CA will form part of this PSM. The 11CB relay will form part of the future
PSM to monitor bus and transmission line protection systems. Figure 3.1 illustrates the
block diagram of the proposed PSM.
9
Modbus
SEL Serial Communications
Fiber
Figure 3.1 Device Integration Diagram
3.2 Logic and Programming
Interaction with the RTAC is performed via AcSELerator RTAC, SEL’s proprietary
software. The bulk of the program is comprised of IEC 61131-3 operators as well as
SEL’s RTAC proprietary extending functions. Structured text is used in cases where the
use of operators and functions becomes cumbersome. All programs are compiled in a
project file. When loaded to the RTAC, all programs are ran sequentially as tasks; the
order is set based on priority of the task and the cycle time is set accounting for its
complexity. The following subsections summarize the process of the programming.
10
3.2.1 Devices
The initial step is to add all devises to be integrated. Each device along with the correct
communications protocol must be selected; in this application, the serial communications
using SEL protocol is chosen. The communication settings are set to match each relay.
The desired metering tags must also be enabled. The Addition of human-machine
interface is also possible and will be integrated in future applications.
3.2.2 Global Variables
As with many programming languages and structures, the RTAC programming
environment allows for the definition of global variables. These variables can be used and
redefined in all programs. The definition of global variables requires user logic of type
GVL. The global variables in the project are define under specific program, user logic of
type program.
3.2.3 CT Test Function Block
A function block is a program template that can be utilized in many instances and under
many other programs. The CT test function block is built in order to accommodate the
testing of all CTs in the system of interest. The test performs several checks in order to
validate CT performance at a given mismatch percentage. A minimum current check
ensures the primary relay is metering enough current to validate all readings; for all
relays in the system, this value is 0.3 amps.
11
All CTs used in all zones are verified against the primary relay’s (11GA) neutral side CT.
Special consideration is given to GSU differential relays (11TA and 11TB) due to the
step up ratio. In addition, a time deadband check is utilized to ensure the proper timing is
maintained between polls and to help set a maximum program (watchdog timer in SEL
RTAC terms). This timer is essential to prevent programs from entering endless loops.
Individual validation of each of the CTs is mapped to alarm points via the RTAC’s tag
processor. These alarm points aid in identification of the CT of concern.
3.2.4 Validation Program
The validation program utilizes the CT test function block. Three functions blocks are
used to evaluate all three phases. One alarm per validation program is used to specify the
percent error threshold. A performance evaluation of the CTs in the system is required to
identify the average metering percent error. The performance evaluation project is used to
obtain the base level of metering error. The monitoring program is used to alarm the
operator or maintenance personnel when metering of a specific CT is outside the set
threshold; this monitoring program settings are based on data collected during the
performance evaluation.
3.2.5 Tag Processor
The tag processor serves as the data mapper. All data entering the RTAC via
communications or data held in global variables is routed to a specified destination [2].
12
The tag processor allows for a very flexible manipulation of the data. If the data is an
alarm point, the tag processor can be used to log its activity.
3.3 Reliability Impact of Monitoring System
Reliability of a power system pertains to the proper performance of all components in the
protection system as well as the scheme. This is determined by the security and
dependability of the system. Security is defined as “the degree of certainty a relay or
relay system will not operate incorrectly” [1]. Dependability is defined as “the degree of
certainty that a relay or relay system will operate correctly” [1]. RTAC increases the
reliability of the power system by constantly detecting and indicating when the CTs are
sending invalid inputs to the relay. This information increases the systems dependability
and security by knowing to fix the CT before an undetected fault or a nuisance trip occurs
due to the invalid inputs. The change in the system reliability with the RTAC can be
calculated using an event tree with CT test intervals of 5 years without the PSM, and test
intervals of 1 second with the PSM.
Instrument
Transformer
IT
Relay
Trip Signal
Breaker
R
TS
B
Figure 3.2 Basic Block Diagram for Protection System Reliability Studies
13
The figure above illustrates the four main components of a protection scheme. For this
project, the instrument transformer will be a current transformer. The relays are two
redundant SEL 300G relays and only one trip signal from both relays is sent to the 230kV
Power Circuit Breaker (PCB). This protection scheme is shown in the figure below:
RELAY 1
CT
TRIP SIGNAL
BREAKER
RELAY 2
Figure 3.3 Hyatt Power Plant Protection System Block Diagram
Inadvertent operation, also known as nuisance tripping, is the event when a protection
device sends a false trip to the breaker. One example of inadvertent operation is when a
CT is saturating and the differential protection calculated an imbalance due to the
saturation, sending a false trip to the breaker. PSM allows detection of the CT saturation
before it reaches the trip pickup point. Figure below illustrates all possible outcomes due
to CT saturation initiating an inadvertent operation.
14
FD
R1
R2
TS
B
Outcome
Inadvertent Operation
Operation Avoided
O
1
B
-
2
-
B
3
-
B
4
B
-
5
-
B
6
-
B
7
B
-
8
-
B
9
-
B
10
-
B
O
F
O
F
O
O
O
F
F
Initiating
Event
F
O
O
F
O
F
F
F
Figure 3.4 Protection System Event Tree
Following the minimum NERC test interval requirements, all devices in the figure are
tested once every five years. Using the unavailability equation below, the reliability can
be calculated[3]:
U=
1
(1 − e−𝜆TC )
TC
15
Where TC is the test interval and l is the failure rate which is the inverse of the mean time
between failures (MTBF). The MTBF for the current transformer is about 500 years [4].
According to SEL, “Historical data show that SEL relays have a mean time between
failures (MTBF) rate of about 300 years” [5]. The MTBF for the trip signals are
determined by the battery charging system which has a MTBF of about 200,000 hours or
22.83 years [6]. The MTBF for the oil circuit breaker with a hydraulic drive is 18.61
years [7]. If we apply all these MTBF and a test interval of 5 years into the unavailability
equation we calculate the following:
UCT w/o PSM =
5yr
1
1
−
(1 − e−𝜆TC ) = (1 − e 500yr ) = 0.002
TC
5
1
1
−
UCT w/ PSM = (1 − e−𝜆TC ) = 1 − (1 − e
TC
5
1𝑠×
1yr
31536000s
500yr
)
= 1.26 × 10−11
Similarly, UR = 0.0033, UTS = 0.0393, and UB = 0.0471. Using this method to calculate
the unavailability, the probability of an inadvertent operation can be calculated. The
results are shown in the table below:
16
Table 3.1 Inadvertent Opening Probabilities
Path
Probability Equation
Probability
without PSM
Probability
with PSM
1
𝑈𝐶𝑇 × (1 − 𝑈𝑅 )2 × (1 − 𝑈𝑇𝑆 ) × (1 − 𝑈𝐵 )
1.82 × 10−3
1.15 × 10−11
2
𝑈𝐶𝑇 × (1 − 𝑈𝑅 )2 × (1 − 𝑈𝑇𝑆 ) × 𝑈𝐵
8.99 × 10−5
5.66 × 10−13
3
𝑈𝐶𝑇 × (1 − 𝑈𝑅 )2 × 𝑈𝑇𝑆
7.81 × 10−5
4.92 × 10−13
4
𝑈𝐶𝑇 × (1 − 𝑈𝑅 ) × 𝑈𝑅 × (1 − 𝑈𝑇𝑆 ) × (1 − 𝑈𝐵 )
6.02 × 10−6
3.79 × 10−14
5
𝑈𝐶𝑇 × (1 − 𝑈𝑅 ) × 𝑈𝑅 × (1 − 𝑈𝑇𝑆 ) × 𝑈𝐵
2.98 × 10−7
1.88 × 10−15
6
𝑈𝐶𝑇 × (1 − 𝑈𝑅 ) × 𝑈𝑅 × 𝑈𝑇𝑆
2.59 × 10−7
1.63 × 10−15
7
𝑈𝐶𝑇 × 𝑈𝑅 × (1 − 𝑈𝑅 ) × (1 − 𝑈𝑇𝑆 ) × (1 − 𝑈𝐵 )
6.02 × 10−6
3.79 × 10−14
8
𝑈𝐶𝑇 × 𝑈𝑅 × (1 − 𝑈𝑅 ) × (1 − 𝑈𝑇𝑆 ) × 𝑈𝐵
2.98 × 10−7
1.88 × 10−15
9
𝑈𝐶𝑇 × 𝑈𝑅 × (1 − 𝑈𝑅 ) × 𝑈𝑇𝑆
2.59 × 10−7
1.63 × 10−15
10
𝑈𝐶𝑇 × 𝑈𝑅 × 𝑈𝑅
2.18 × 10−8
1.37 × 10−16
From the protection event tree the probability the breaker will inadvertently open during
a non-fault is the sum of paths 1, 4, and 7. Without a PSM, the probability the breaker
will inadvertently open is 0.00183. With a PSM, the probability the breaker will open is
1.16 × 10−11 . The probability is significantly reduced when PSM is included in the
reliability calculations.
rth American Electric Reliability Corporation (NERC) establishes and enforces
17
CHAPTER 4
APPLICATION OF MATHEMATICAL MODEL
4.1 CT Metering Performance Evaluation
The performance evaluation required the use of a version of the PSM project that was
developed to count how many readings were made at different percent error settings.
Figure 4.1 illustrates a snapshot from AcSELerator RTAC. Appendix C presents detailed
information of settings and programming.
Figure 4.1 RTAC Program Layout
18
The settings for each of the devices was configured to match the generator/motor, GSU
and cable relays. This task was performed based on data from maintenance and
commissioning records. A set of global variables named “GLOBAL_CONSTANTS”,
was created to allow quick access to data by all programs. The program
“ADJUSTABLE_CONSTANTS” defines the values that will remain fixed. A second set
of global variables, “LOGGING_VARIABLES”, is set to allow mapping of alarm points
via the tag processor.
The “CT_TEST_FUNCTION_BLOCK” as the name states, forms the template for the
validation programs “CT_nn_PERCENT_ERROR”, where nn is the percent of error to be
verified. A counting program, “CT_VALIDATION_COUNTERS”, was added
statistically evaluate the average percentage of error read across all CTs in the system.
The program “TIME_COMPARE_COUNTERS” was created to verify the average time
between polling cycles. All alarm points were routed via the tag processor and set to
trigger alarm logs. These alarm logs yielded the data necessary to set a suitable alarms
when employing the PSM. Figure 4.2 provides the graph of the alarm log for a period of
five hours when unit 4 of Hyatt Power Plant was brought online and ramped up to its full
capacity.
19
140
12
120
10
Load (MW)
8
80
6
60
4
% Error Validation
100
40
2
20
9:15
9:12
9:09
9:06
9:03
9:00
0
8:57
0
Time
LOAD
% VALIDATION
Figure 4.2 Current Transformer Performance Evaluation
From the graph, we obtain the percent error readings based on alarm logs for the multiple
load conditions. Based on the alarm logs it is desireable to employ a steady state
verification process that will block erroneous indications due to quick changes in power
output or transient conditions based on load variation. Metering error at steady state was
verified to be less than one percent. The graph provided sufficient data and no statistical
analysis was necessary.
20
4.2 Implementation of Monitoring System
With the data gathered during the performance evaluation, the PSM project file was
modified to be used in monitoring the CT performance and meet PRC-005-2
requirements. With average readings verified at one percent, two settings were chosen to
provide alarming. One alarm was set to activate at or above three percent. A second
setting chosen to be at 10 percent, the accuracy guaranteed by CT manufacturers at 20
times the secondary current. Appendix C summarizes the settings of the PSM at Hyatt
Power Plant unit 4.
While the RTAC provides time synchronization of all connected relays via
Communications channels, polling of all devices is not synchronized. Intervals between
polls will vary based on the designated program sequence, speed of communications
protocol and ultimately, the processing speed of the individual devices. For this reason,
steady state verification is needed to ensure that the metered current is not varying due to
load conditions or other transient conditions. A slight difference between polled device
readings is expected but due to steady state, their difference should be within CT’s rated
accuracy of 10%.
Per California Independent System Operator, the maximum power ramp rate of 30MW
per minute. Given the rating of the largest machines at Hyatt Power Plant (123MW), this
equates to approximately 0.4% change per second. A value of 28.4 (0.5%/sec) amps
primary is used to verify the system is at steady state; if the current metered by generator
21
relay 11GA is increasing or decreasing at a higher rate, a block is issued to the validation
logic, preventing erroneous readings. Programming of such verification requires the use
of structured text and IEC 61131-3 operators in two separate programs.
4.3 Performance Evaluation of PSM
With the steady state verification program implemented, the readings at or below two
percent. This readings are suitable based on our settings. The current system may be
accessed locally via USB interface. The steady state program will be modified at a later
date after gathering data on average ramp rates instead of maximum aggregate ramp rate
dictated by CAISO. In figure 4.3 below, the times when the generator is commanded to
ramp up or down still yield readings that may cause the monitoring system to issue false
alarms.
22
140
9
8
120
Load (MW)
6
80
5
60
4
3
% Error Validation
7
100
40
2
20
1
8/7/13 9:01
8/7/13 6:37
8/7/13 4:13
8/7/13 1:49
8/6/13 23:25
8/6/13 21:01
8/6/13 18:37
8/6/13 16:13
0
8/6/13 13:49
0
Date & Time
LOAD
% VALIDATION
Figure 4.3 Current Transformer Performance Evaluation with Steady State Permissive
23
CHAPTER 5
CONCLUSION
Protection system monitoring can be implemented using modern microprocessor based
relays and automation controllers. PRC-005-2 requirements can be met without the need
of phasor measurement units. Even though the full capability of the monitoring system
was not achieved, it yielded results that can be easily integrated to an automated
maintenance and reporting program.
The reliability of the overall protection system can be improved by performing
continuous checks on system components. Detection of abnormal operating conditions in
the protection system can help prevent misoperation or failures, helping maintain
continuity of service when it is needed.
Protection system integration is an area that receives little attention in power systems
engineering. It is quickly becoming a crucial field as system automation and control is
gaining popularity amongst operators at all levels.
24
APPENDIX A
Protection and Communications Single Line Diagram
26
APPENDIX B
PSM Logic Diagram
31
APPENDIX C
PSM Settings and Programming Summary
A.1 CT Metering Performance Evaluation
The settings and programming details of this RTAC project file are omitted due to
amount of data. A copy of the project file is issued with this report for reference and can
be viewed by using AcSELerator RTAC software.
A.2 PSM Project File
Note that only non default settings are listed to aid in summarizing this report.
A.2.1 Device Settings
SEL_300G_A (11GA) Settings
Serial Communications Port
Serial Communications Port Type
Baud Rate
Data Bits
Parity Bit
Stop Bit
RTS_CTS
Xon / Xoff
Level 1 Password
Level 2 Password
Poll CASCII Retries
Poll CASCII Inactivity Timeout
Poll Binary Retries
Poll Binary Inactivity Timeout
Slow Poll Mode Multiplier
Transmit Fast Unsolicited Write Messaging on Startup
UTC Offset
DST Enabled
Com_01
EIA232
19200
8
None
1
FALSE
TRUE
OTTER
TAIL
3
8000
3
750
5
FALSE
0
FALSE
32
SEL_300G_A (11GA) Tags
SEL_300G_A_SEL.FM_INST_IA87
SEL_300G_A_SEL.FM_INST_IB87
SEL_300G_A_SEL.FM_INST_IC87
SEL_300G_A_SEL.FM_INST_IA
SEL_300G_A_SEL.FM_INST_IB
SEL_300G_A_SEL.FM_INST_IC
SEL_300G_A_SEL.FM_INST_52A
SEL_300G_A_SEL.CA_STA_ST
CMV
CMV
CMV
CMV
CMV
CMV
SPS
INS
SEL_300G_B (11GB) Settings
Serial Communications Port
Serial Communications Port Type
Baud Rate
Data Bits
Parity Bit
Stop Bit
RTS_CTS
Xon / Xoff
Level 1 Password
Level 2 Password
Poll CASCII Retries
Poll CASCII Inactivity Timeout
Poll Binary Retries
Poll Binary Inactivity Timeout
Slow Poll Mode Multiplier
Transmit Fast Unsolicited Write Messaging on Startup
UTC Offset
DST Enabled
SEL_300G_B (11GB) Tags
SEL_300G_B_SEL.FM_INST_IA87
SEL_300G_B_SEL.FM_INST_IB87
SEL_300G_B_SEL.FM_INST_IC87
SEL_300G_B_SEL.FM_INST_IA
SEL_300G_B_SEL.FM_INST_IB
SEL_300G_B_SEL.FM_INST_IC
SEL_300G_B_SEL.FM_INST_IA87
CMV
CMV
CMV
CMV
CMV
CMV
CMV
Com_02
EIA232
19200
8
None
1
FALSE
TRUE
OTTER
TAIL
3
8000
3
750
5
FALSE
0
FALSE
33
SEL_300G_B_SEL.FM_INST_IB87
CMV
SEL_387_A (11TA) Settings
Serial Communications Port
Serial Communications Port Type
Baud Rate
Data Bits
Parity Bit
Stop Bit
RTS_CTS
Xon / Xoff
Level 1 Password
Level 2 Password
Poll CASCII Retries
Poll CASCII Inactivity Timeout
Poll Binary Retries
Poll Binary Inactivity Timeout
Slow Poll Mode Multiplier
Transmit Fast Unsolicited Write Messaging on Startup
UTC Offset
DST Enabled
SEL_387_A (11TA) Tags
SEL_387_A_SEL.FM_INST_IAW1
SEL_387_A_SEL.FM_INST_IAW2
SEL_387_A_SEL.FM_INST_IBW1
SEL_387_A_SEL.FM_INST_IBW2
SEL_387_A_SEL.FM_INST_ICW1
SEL_387_A_SEL.FM_INST_ICW2
SEL_387_A_SEL.FM_INST_IAW1
SEL_387_A_SEL.FM_INST_IAW2
CMV
CMV
CMV
CMV
CMV
CMV
CMV
CMV
Com_03
EIA232
19200
8
None
1
False
True
OTTER
TAIL
3
8000
3
750
5
False
0
False
34
SEL_387_B (11TB) Settings
Serial Communications Port
Serial Communications Port Type
Baud Rate
Data Bits
Parity Bit
Stop Bit
RTS_CTS
Xon / Xoff
Level 1 Password
Level 2 Password
Poll CASCII Retries
Poll CASCII Inactivity Timeout
Poll Binary Retries
Poll Binary Inactivity Timeout
Slow Poll Mode Multiplier
Transmit Fast Unsolicited Write Messaging on Startup
UTC Offset
DST Enabled
SEL_387_B (11TB) Tags
SEL_387_B_SEL.FM_INST_IAW1
SEL_387_B_SEL.FM_INST_IAW2
SEL_387_B_SEL.FM_INST_IBW1
SEL_387_B_SEL.FM_INST_IBW2
SEL_387_B_SEL.FM_INST_ICW1
SEL_387_B_SEL.FM_INST_ICW2
SEL_387_B_SEL.FM_INST_IAW1
SEL_387_B_SEL.FM_INST_IAW2
CMV
CMV
CMV
CMV
CMV
CMV
CMV
CMV
Com_04
EIA232
19200
8
None
1
False
True
OTTER
TAIL
3
8000
3
750
5
False
0
False
35
SEL_311L_A (11CA) Settings
Serial Communications Port
Serial Communications Port Type
Baud Rate
Data Bits
Parity Bit
Stop Bit
RTS_CTS
Xon / Xoff
Level 1 Password
Level 2 Password
Poll CASCII Retries
Poll CASCII Inactivity Timeout
Poll Binary Retries
Poll Binary Inactivity Timeout
Slow Poll Mode Multiplier
Transmit Fast Unsolicited Write Messaging on Startup
UTC Offset
DST Enabled
Com_05
EIA232
19200
8
None
1
False
True
OTTER
TAIL
3
8000
3
750
5
False
0
False
SEL_311L_A (11CA) Tags
SEL_311L_A_SEL.FM_INST_IA
SEL_311L_A_SEL.FM_INST_IB
SEL_311L_A_SEL.FM_INST_IC
CMV
CMV
CMV
A.2.2 Tag Processor
Build
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
Destination Tag Name
SystemTags.User_Logged_On
SystemTags.User_Logged_Off
SystemTags.Unsuccessful_Log_O
n_Attempt
SystemTags.User_Changed_Settin
gs
SystemTags.Password_Changed
SystemTags.User_Information_Ch
anged
SystemTags.User_Removed
SystemTags.User_Added
DT
Data
Type
STR
STR
STR
STR
STR
STR
STR
STR
Source Expression
SE Data
Type
36
TRUE
TRUE
TRUE
TRUE
SystemTags.Device_Upgrade
SystemTags.Factory_Reset
SystemTags.Logs_Cleared
SystemTags.Power_Up_Descriptio
n
SystemTags.Disable_Password_Ju
mper_Enabled
SystemTags.Port_Power_Overcurr
ent
SystemTags.Port_Power_Overcurr
ent
SystemTags.Application_Status
SystemTags.System_Watchdog_E
xpired
SystemTags.Out_Of_Memory_Sys
tem_Reset
SystemTags.System_Hardware_Fa
ilure
SystemTags.HMI_Control_Operati
on
SystemTags.HMI_Analog_Write_
Operation
SystemTags.IED_Events_Cleared
STR
STR
STR
STR
ALARM_MIN_CUR_A_3
BOOL
TRUE
ALARM_IA87_300G_A_3
BOOL
TRUE
ALARM_IA_300G_B_3
BOOL
TRUE
ALARM_IA87_300G_B_3
BOOL
TRUE
ALARM_IAW1_387_A_3
BOOL
TRUE
ALARM_IAW2_387_A_3
BOOL
TRUE
ALARM_IAW1_387_B_3
BOOL
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
FALSE
FALSE
TRUE
SPS
SPS
SPS
STR
STR
STR
STR
STR
STR
STR
CT_3_PERCENT_VALI
DATION.MIN_CURREN
T_A_3
CT_3_PERCENT_VALI
DATION.CK_IA87_300G
_A_3
CT_3_PERCENT_VALI
DATION.CK_IA_300G_
B_3
CT_3_PERCENT_VALI
DATION.CK_IA87_300G
_B_3
CT_3_PERCENT_VALI
DATION.CK_IAW1_387
_A_3
CT_3_PERCENT_VALI
DATION.CK_IAW2_387
_A_3
CT_3_PERCENT_VALI
DATION.CK_IAW1_387
_B_3
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
37
TRUE
ALARM_IAW2_387_B_3
BOOL
TRUE
ALARM_IA_311L_3
BOOL
TRUE
ALARM_MIN_CURRENT_B_3
BOOL
TRUE
ALARM_IB87_300G_A_3
BOOL
TRUE
ALARM_IB_300G_B_3
BOOL
TRUE
ALARM_IB87_300G_B_3
BOOL
TRUE
ALARM_IBW1_387_A_3
BOOL
TRUE
ALARM_IBW2_387_A_3
BOOL
TRUE
ALARM_IBW1_387_B_3
BOOL
TRUE
ALARM_IBW2_387_B_3
BOOL
TRUE
ALARM_IB_311L_3
BOOL
TRUE
ALARM_MIN_CURRENT_C_3
BOOL
TRUE
ALARM_IC87_300G_A_3
BOOL
TRUE
ALARM_IC_300G_B_3
BOOL
TRUE
ALARM_IC87_300G_B_3
BOOL
TRUE
ALARM_ICW1_387_A_3
BOOL
TRUE
ALARM_ICW2_387_A_3
BOOL
CT_3_PERCENT_VALI
DATION.CK_IAW2_387
_B_3
CT_3_PERCENT_VALI
DATION.CK_IA_311L_3
CT_3_PERCENT_VALI
DATION.MIN_CURREN
T_B_3
CT_3_PERCENT_VALI
DATION.CK_IB87_300G
_A_3
CT_3_PERCENT_VALI
DATION.CK_IB_300G_
B_3
CT_3_PERCENT_VALI
DATION.CK_IB87_300G
_B_3
CT_3_PERCENT_VALI
DATION.CK_IBW1_387
_A_3
CT_3_PERCENT_VALI
DATION.CK_IBW2_387
_A_3
CT_3_PERCENT_VALI
DATION.CK_IBW1_387
_B_3
CT_3_PERCENT_VALI
DATION.CK_IBW2_387
_B_3
CT_3_PERCENT_VALI
DATION.CK_IB_311L_3
CT_3_PERCENT_VALI
DATION.MIN_CURREN
T_C_3
CT_3_PERCENT_VALI
DATION.CK_IC87_300G
_A_3
CT_3_PERCENT_VALI
DATION.CK_IC_300G_
B_3
CT_3_PERCENT_VALI
DATION.CK_IC87_300G
_B_3
CT_3_PERCENT_VALI
DATION.CK_ICW1_387
_A_3
CT_3_PERCENT_VALI
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
38
TRUE
ALARM_ICW1_387_B_3
BOOL
TRUE
ALARM_ICW2_387_B_3
BOOL
TRUE
ALARM_IC_311L_3
BOOL
TRUE
ALARM_THREE_PERCENT_V
ALIDATION
BOOL
FALSE
FALSE
TRUE
ALARM_MIN_CUR_A_10
BOOL
TRUE
ALARM_IA87_300G_A_10
BOOL
TRUE
ALARM_IA_300G_B_10
BOOL
TRUE
ALARM_IA87_300G_B_10
BOOL
TRUE
ALARM_IAW1_387_A_10
BOOL
TRUE
ALARM_IAW2_387_A_10
BOOL
TRUE
ALARM_IAW1_387_B_10
BOOL
TRUE
ALARM_IAW2_387_B_10
BOOL
TRUE
ALARM_IA_311L_10
BOOL
TRUE
ALARM_MIN_CURRENT_B_10
BOOL
TRUE
ALARM_IB87_300G_A_10
BOOL
DATION.CK_ICW2_387
_A_3
CT_3_PERCENT_VALI
DATION.CK_ICW1_387
_B_3
CT_3_PERCENT_VALI
DATION.CK_ICW2_387
_B_3
CT_3_PERCENT_VALI
DATION.CK_IC_311L_3
CT_3_PERCENT_VALI
DATION.THREE_PERC
ENT_VALIDATION
CT_10_PERCENT_VALI
DATION.MIN_CURREN
T_A_10
CT_10_PERCENT_VALI
DATION.CK_IA87_300G
_A_10
CT_10_PERCENT_VALI
DATION.CK_IA_300G_
B_10
CT_10_PERCENT_VALI
DATION.CK_IA87_300G
_B_10
CT_10_PERCENT_VALI
DATION.CK_IAW1_387
_A_10
CT_10_PERCENT_VALI
DATION.CK_IAW2_387
_A_10
CT_10_PERCENT_VALI
DATION.CK_IAW1_387
_B_10
CT_10_PERCENT_VALI
DATION.CK_IAW2_387
_B_10
CT_10_PERCENT_VALI
DATION.CK_IA_311L_1
0
CT_10_PERCENT_VALI
DATION.MIN_CURREN
T_B_10
CT_10_PERCENT_VALI
DATION.CK_IB87_300G
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
39
TRUE
ALARM_IB_300G_B_10
BOOL
TRUE
ALARM_IB87_300G_B_10
BOOL
TRUE
ALARM_IBW1_387_A_10
BOOL
TRUE
ALARM_IBW2_387_A_10
BOOL
TRUE
ALARM_IBW1_387_B_10
BOOL
TRUE
ALARM_IBW2_387_B_10
BOOL
TRUE
ALARM_IB_311L_10
BOOL
TRUE
ALARM_MIN_CURRENT_C_10
BOOL
TRUE
ALARM_IC87_300G_A_10
BOOL
TRUE
ALARM_IC_300G_B_10
BOOL
TRUE
ALARM_IC87_300G_B_10
BOOL
TRUE
ALARM_ICW1_387_A_10
BOOL
TRUE
ALARM_ICW2_387_A_10
BOOL
TRUE
ALARM_ICW1_387_B_10
BOOL
TRUE
ALARM_ICW2_387_B_10
BOOL
TRUE
ALARM_IC_311L_10
BOOL
_A_10
CT_10_PERCENT_VALI
DATION.CK_IB_300G_
B_10
CT_10_PERCENT_VALI
DATION.CK_IB87_300G
_B_10
CT_10_PERCENT_VALI
DATION.CK_IBW1_387
_A_10
CT_10_PERCENT_VALI
DATION.CK_IBW2_387
_A_10
CT_10_PERCENT_VALI
DATION.CK_IBW1_387
_B_10
CT_10_PERCENT_VALI
DATION.CK_IBW2_387
_B_10
CT_10_PERCENT_VALI
DATION.CK_IB_311L_1
0
CT_10_PERCENT_VALI
DATION.MIN_CURREN
T_C_10
CT_10_PERCENT_VALI
DATION.CK_IC87_300G
_A_10
CT_10_PERCENT_VALI
DATION.CK_IC_300G_
B_10
CT_10_PERCENT_VALI
DATION.CK_IC87_300G
_B_10
CT_10_PERCENT_VALI
DATION.CK_ICW1_387
_A_10
CT_10_PERCENT_VALI
DATION.CK_ICW2_387
_A_10
CT_10_PERCENT_VALI
DATION.CK_ICW1_387
_B_10
CT_10_PERCENT_VALI
DATION.CK_ICW2_387
_B_10
CT_10_PERCENT_VALI
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
40
TRUE
FALSE
TRUE
ALARM_TEN_PERCENT_VALI
DATION
BOOL
ONE_PERCENT_TOTAL_COUN
TS
TRUE
TWO_PERCENT_TOTAL_COU
NTS
TRUE
THREE_PERCENT_TOTAL_CO
UNTS
TRUE
FOUR_PERCENT_TOTAL_COU
NTS
TRUE
FIVE_PERCENT_TOTAL_COU
NTS
TRUE
SIX_PERCENT_TOTAL_COUN
TS
TRUE
SEVEN_PERCENT_TOTAL_CO
UNTS
TRUE
EIGHT_PERCENT_TOTAL_CO
UNTS
TRUE
NINE_PERCENT_TOTAL_COU
NTS
TRUE
TEN_PERCENT_TOTAL_COUN
TS
MV
FALSE
TRUE
ALARM_SS_VALIDATION
BOOL
TRUE
SS_PERMISSIVE
BOOL
MV
DATION.CK_IC_311L_1
0
CT_10_PERCENT_VALI
DATION.TEN_PERCEN
T_VALIDATION
BOOL
CT_VALIDATION_COU
NTERS.ONE_PERCENT
_TOTAL
CT_VALIDATION_COU
NTERS.TWO_PERCENT
_TOTAL
CT_VALIDATION_COU
NTERS.THREE_PERCE
NT_TOTAL
CT_VALIDATION_COU
NTERS.FOUR_PERCEN
T_TOTAL
CT_VALIDATION_COU
NTERS.FIVE_PERCENT
_TOTAL
CT_VALIDATION_COU
NTERS.SIX_PERCENT_
TOTAL
CT_VALIDATION_COU
NTERS.SEVEN_PERCE
NT_TOTAL
CT_VALIDATION_COU
NTERS.EIGHT_PERCEN
T_TOTAL
CT_VALIDATION_COU
NTERS.NINE_PERCENT
_TOTAL
CT_VALIDATION_COU
NTERS.TEN_PERCENT
_TOTAL
MV
IDIFF_CHECK.SS_CHE
CK
IDIFF_CHECK.SS_CHE
CK
BOOL
MV
MV
MV
MV
MV
MV
MV
MV
MV
BOOL
41
A.2.3 Main Controller
Enabled
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
TRUE
Task cycle time
Task watchdog time
100
15000
Item
SEL_300G_A_SEL
SEL_300G_B_SEL
SEL_311L_A_SEL
SEL_387_A_SEL
SEL_387_B_SEL
ADJUSTABLE_CONSTANTS
STEADY_STATE_CHECK
CT_3_PERCENT_VALIDATION
CT_10_PERCENT_VALIDATION
CT_VALIDATION_COUNTERS
Tag Processor
IDIFF_CHECK
Order
1
2
3
4
5
6
7
8
9
10
11
12
ms
ms
A.2.4 User Logic - GLOBAL_CONSTANTS (Structured Text)
VAR_GLOBAL
HI_SIDE_SCALE:REAL;
MINIMUM_CURRENT:REAL;
TIME_DEADBAND:REAL;
CT_300G_RATIO:REAL;
THREE_PERCENT:REAL;
TEN_PERCENT:REAL;
SS_RATE:REAL;
I1:REAL;
I2:REAL;
IDIFF:REAL;
SS_PERMISSIVE:BOOL;
END_VAR
A.2.5 User Logic - ADJUSTABLE_CONSTANTS (Structured Text & Proprietary
Function)
PROGRAM ADJUSTABLE_CONSTANTS
VAR
END_VAR
42
A.2.6 User Logic – LOGGING_VARIABLES (Structured Text)
VAR_GLOBAL
ALARM_MIN_CUR_A_3:BOOL;
ALARM_IA87_300G_A_3:BOOL;
ALARM_IA_300G_B_3: BOOL;
ALARM_IA87_300G_B_3:BOOL;
ALARM_IAW1_387_A_3:BOOL;
ALARM_IAW2_387_A_3:BOOL;
ALARM_IAW1_387_B_3:BOOL;
ALARM_IAW2_387_B_3:BOOL;
ALARM_IA_311L_3:BOOL;
ALARM_MIN_CURRENT_B_3:BOOL;
ALARM_IB87_300G_A_3:BOOL;
ALARM_IB_300G_B_3: BOOL;
ALARM_IB87_300G_B_3:BOOL;
ALARM_IBW1_387_A_3:BOOL;
ALARM_IBW2_387_A_3:BOOL;
ALARM_IBW1_387_B_3:BOOL;
ALARM_IBW2_387_B_3:BOOL;
ALARM_IB_311L_3:BOOL;
ALARM_MIN_CURRENT_C_3:BOOL;
ALARM_IC87_300G_A_3:BOOL;
ALARM_IC_300G_B_3:BOOL;
ALARM_IC87_300G_B_3:BOOL;
ALARM_ICW1_387_A_3:BOOL;
ALARM_ICW2_387_A_3:BOOL;
ALARM_ICW1_387_B_3:BOOL;
ALARM_ICW2_387_B_3:BOOL;
ALARM_IC_311L_3:BOOL;
ALARM_THREE_PERCENT_VALIDATION:BOOL;
ALARM_MIN_CUR_A_10:BOOL;
43
ALARM_IA87_300G_A_10:BOOL;
ALARM_IA_300G_B_10:BOOL;
ALARM_IA87_300G_B_10:BOOL;
ALARM_IAW1_387_A_10:BOOL;
ALARM_IAW2_387_A_10:BOOL;
ALARM_IAW1_387_B_10:BOOL;
ALARM_IAW2_387_B_10:BOOL;
ALARM_IA_311L_10:BOOL;
ALARM_MIN_CURRENT_B_10:BOOL;
ALARM_IB87_300G_A_10:BOOL;
ALARM_IB_300G_B_10:BOOL;
ALARM_IB87_300G_B_10:BOOL;
ALARM_IBW1_387_A_10:BOOL;
ALARM_IBW2_387_A_10:BOOL;
ALARM_IBW1_387_B_10:BOOL;
ALARM_IBW2_387_B_10:BOOL;
ALARM_IB_311L_10:BOOL;
ALARM_MIN_CURRENT_C_10:BOOL;
ALARM_IC87_300G_A_10:BOOL;
ALARM_IC_300G_B_10:BOOL;
ALARM_IC87_300G_B_10:BOOL;
ALARM_ICW1_387_A_10:BOOL;
ALARM_ICW2_387_A_10:BOOL;
ALARM_ICW1_387_B_10:BOOL;
ALARM_ICW2_387_B_10:BOOL;
ALARM_IC_311L_10:BOOL;
ALARM_TEN_PERCENT_VALIDATION:BOOL;
THREE_PERCENT_TOTAL_COUNTS:MV;
TEN_PERCENT_TOTAL_COUNTS:MV;
TIME_TOTAL_AI87:MV;
TIME_TOTAL_IB:MV;
TIME_TOTAL_BI87:MV;
TIME_TOTAL_IW1A:MV;
TIME_TOTAL_IW2A:MV;
TIME_TOTAL_IW1B:MV;
TIME_TOTAL_IW2B:MV;
TIME_TOTAL_311L:MV;
ALARM_SS_VALIDATION:BOOL;
END_VAR
A.2.7 User Logic – STEADY_STATE_CHECK (Structured Text)
PROGRAM STEADY_STATE_CHECK
VAR
TInst:TI;
TUP:BOOL;
END_VAR
44
I1:=SEL_300G_A_SEL.FM_INST_IA.instCVal.mag;
TInst(IN:=FALSE, PT:=T#1S);
TUP := TInst.Q;
IF TUP=TRUE THEN
I2:=SEL_300G_A_SEL.FM_INST_IA.instCVal.mag;
END_IF
TUP:=FALSE;
A.2.8 User Logic – IDIFF_CHECK (Structured Text & Proprietary Function)
PROGRAM IDIFF_CHECK
VAR
END_VAR
VAR_OUTPUT
SS_CHECK:BOOL;
END_VAR
A.2.9 User Logic – CT_TEST_FUNCTION_BLOCK (Structured Text &
Proprietary Function)
Appendix B illustrates logic for this function block.
A.2.10 User Logic – CT_3_PERCENT_VALIDATION (Structured Text &
Proprietary Function)
Appendix B illustrates logic for this function block.
45
A.2.11 User Logic – CT_10_PERCENT_VALIDATION (Structured Text &
Proprietary Function)
Appendix B illustrates logic for this function block.
A.2.12 User Logic – CT_VALIDATION_COUNTERS (Structured Text &
Proprietary Function)
PROGRAM CT_VALIDATION_COUNTERS
VAR
IA_3:CTU;
IA_10:CTU;
T3:R_TRIG;
T10:R_TRIG;
END_VAR
VAR_OUTPUT
THREE_PERCENT_TOTAL:MV;
TEN_PERCENT_TOTAL:MV;
END_VAR
46
REFERENCES
[1] ANSI/IEEE Standard C37.2, Standard Electrical Power System Device
Function.
[2] “Real-Time Automation Controller Instruction Manual”, Schweitzer
Engineering Laboratories, 2013.
[3] Billinton, Roy and Allan, Ronald, Reliability Evaluation of Power Systems.
1996.
[4] Fleming, Bill, and Lee, Tony J. “RELIABILITY ANALYSIS OF
TRANSMISSION PROTECTION USING FAULT TREE METHODS”,
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