Testing of IEC 61850 Compliant Smart Grid Devices: A Malaysian Experience
1M.I. RIDWAN,
1N.S. MISWAN,
1M.N. NORAN,
1M.S.M. SHOKRI,
2H.N. AWANG,
2A. MUSA
1TNB RESEARCH SDN BHD
2TENAGA NASIONAL BERHAD
MALAYSIA
AORC Technical meeting 2014C4-1093
http : //www.cigre.org
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SUMMARY
One of the important aspects to ensure the success of a Smart Grid implementation is the ability of
the devices and systems in a Smart Grid domain to be able to seamlessly communicate and exchange
information with each other. This aspect, which is also referred as interoperability, is crucial for the
execution of functions that are defined in a Smart Grid domain, regardless whether it is a distributed or
centralized function. To ensure interoperability is implemented successfully in a Smart Grid domain, it
is imperative for power utilities to acquire know-now on the relevant open standard based Smart Grid
technologies that can ensure interoperability without fail. Smart Grid solutions with proprietary
technology may pose significant long term risks to utilities, such as expensive replacement of devices
and system extension due to over dependency to single vendor , low flexibility to define new
requirements and susceptible to technology obsolescence from the single vendor.
Interoperability in a Smart Grid domain is crucial to ensure the seamless information exchange
between devices and systems in the domain to execute their intended functions. Standardization bodies
such as the Institute of Electrical and Electronic Engineers (IEEE), International Electrotechnical
Committee (IEC) and National Institute of Standards and Technology (NIST) have published
standards, guideline and roadmaps suggesting on the technologies that can enable seamless
interoperability between devices and systems in a Smart Grid domain. For communications related to
power system and electrical substations in Smart Grid domain, IEC 61850 standard has been
recognized as the open standard that enables interoperability through its standardized data models and
communication services. These data models and communication services are mapped to the
mainstream Ethernet technology, which has allowed IEC 61850 to be future proof regardless of the
advancements of communication technology.
As the public electric utility company in Malaysia, Tenaga Nasional Berhad (TNB) believes that the
integration of solutions from different vendors using open standard is the way forward and has the
promising potential to provide substantial cost savings in the near future. TNB has identified the IEC
61850 standard as the key enabler standard for this purpose and has included the standard as a part of
the long term technology implementation plan under the TNB Technology Road Map (TRM). To
ensure the successful implementation of IEC 61850 standard in a Smart Grid domain, TNB has
embarked in several initiatives, which are also defined in TNB TRM. The initiatives include the
development of an IEC 61850 laboratory, new product acceptance process for IEC 61850 compliant
devices and in-house software applications for IEC 61850 substations. These initiatives are vital for
TNB not only to pave the path to realize TRM vision, but also to obtain in-depth understanding
regarding IEC 61850 and to develop in-house expertise on the subject. Although IEC 61850 promises
interoperability, it is imperative for users to understand the detailed methodologies and know-how
specified in IEC 61850 to successfully achieve interoperability during the implementation stage. This
paper will discuss TNB’s experience on the interoperability testing of IEC 61850 compliant devices
and highlights some of the findings which were observed during the execution of the initiatives above.
KEYWORDS
IEC 61850, Intelligent Electronic Devices (IEDs), Interoperability, Smart Grid, Substation Configuration Language (SCL), Substation Information Management System (SIMS), Substation
Protection, Automation and Control System (SPACS), System Verification and Simulation (SVS)
Laboratory
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1. Introduction
Interoperability in a Smart Grid domain is crucial to ensure the seamless information exchange
between devices and systems in the domain to execute their intended functions. Standardization bodies
such as the Institute of Electrical and Electronic Engineers (IEEE), International Electrotechnical
Committee (IEC) and National Institute of Standards and Technology (NIST) have published
standards, guideline and roadmaps suggesting on the technologies that can enable seamless
interoperability between devices and systems in a Smart Grid domain [1,2,3]. For communications
related to power system and electrical substations in Smart Grid domain, IEC 61850 has been
recognized as the open standard that enables interoperability through its standardized data models and
communication services [4]. These data models and communication services are mapped to the
mainstream Ethernet technology, which has allowed IEC 61850 to be future proof regardless of the
advancements of communication technology [5].
Realizing the benefits that can be exploited from the implementation of IEC 61850 standard, Tenaga
Nasional Berhad (TNB), a public electric utility company in Malaysia has recognized IEC 61850 as
the key enabler standard in the long term technology implementation plan which is called Technology
Road Map (TRM). TRM defines “Smart and Intelligent Electricity Delivery System” as TNB’s own
definition of Smart Grid. The vision of TRM is to achieve the “Smart and Intelligent Electricity
Delivery System” by the year 2020, which smart substation based on IEC 61850 standard has been
identified as one of the major contributors for TNB to achieve the vision [6]. The overview of TNB
TRM is illustrated in Fig. 1 below.
Fig. 1. TNB Technology Roadmap Destinations and Enabling Technology
Under TRM, a cluster of technologies have been identified to achieve the vision of “Smart and
Intelligent Electricity Delivery System” by the year 2020. The vision is to develop smart substations
equipped with integrated Substation Protection, Automation and Control System (SPACS), which is
TNB’s term for SAS. Realizing the capabilities and potential benefits of IEC 61850, the standard has
been identified as the key enabler standard and foundation for the technologies. Fig. 2 highlights the
cluster of technologies in TRM.
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Fig. 2. Clusters of Technology under TRM with IEC 61850 Standard as the Enabler
With IEC 61850, TNB expects to achieve the following goals:
1. Integration of SPACS with IEDs from different vendors, or multi-vendor solution. This is to reduce the risk of common cause of failure and failure modes of IEDs from the same vendor
2. Standardized and self descriptive data models which explicitly defines the functions in power system domain. Such feature will simplify the engineering and configuration of SPACS.
3. Seamless exchange of information between multi-vendor devices using standardized
communication services.
4. Vendor independent engineering and maintenance tools to ease the training and change
management process of end users in maintaining SPACS.
To ensure that the above expectations are met, it is imperative for TNB to have the facility, tools and
procedure to:
1. Test IEC 61850 compliant devices and systems to ensure the functions are actually available and within the required performance criteria
2. Confirm the interoperability of the devices in utilizing IEC 61850 data models and communication services for information exchange
3. Identify and rectify potential issues before the devices are implemented in TNB system
4. Understand the specific implementation of IEC 61850 by vendors due to the open nature of the standard
Hence, in July 2007, the Engineering Department of TNB Transmission Division has appointed
TNB Research Sdn Bhd (TNBR), a wholly owned subsidiary of TNB, to carry out a 3 year R&D
program called “Research and Development of Substation Automation System based on IEC 61850
for Optimal Substation Design in TNB”. As part of the research program deliverables, an in-house
research and testing laboratory which is the System Verification and Simulation (SVS) Laboratory has
been developed. The laboratory is equipped with IEC 61850 compliant IEDs and system which
simulates the communication of secondary equipment as per actual substation. The overview of the
SVS Laboratory is shown in Fig. 3.
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Fig. 3. SVS Laboratory in TNB Research Sdn Bhd
The next section will discuss on the overall design, communication architecture and capabilities of
the SVS Laboratory.
2. TNB IEC 61850 System Verification and Simulation (SVS) Laboratory
SVS laboratory is designed to replicate a typical configuration of 132kV Air Insulated Substation
(AIS). The configuration follows a double bus-bar configuration with two over headline bays, one bus
coupler bay, two HV transformer bays and two MV transformer bays. Each bay is assigned with 2
protection IEDs with duplicated functions of Main 1 and Main 2 together with 1 control IED. The
IEDs are connected to a dedicated Ethernet Switch for each bay using star topology through RJ45
cables. The Ethernet Switches between bays are connected using fiber optic cables that form a ring
topology network. The ring topology provides n-1 redundancy of the network connection through the
Rapid Spanning Tree Protocol (RSTP). This configuration has allowed the SVS laboratory to emulate
IEC 61850 station bus communication architecture as in the actual substations. Fig. 4 illustrates the
physical communication architecture of the laboratory.
Fig. 4. Physical Communication Architecture for SVS Laboratory
While the physical communication architecture describes the physical connection between devices,
the information flow of the SVS laboratory is described by the logical communication architecture.
IEC 61850 services such as Manufacturer Messaging Specification (MMS) and Generic Object
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Oriented Substation Event (GOOSE) are implemented for client-server and server-server
communication. Fig. 5 describes the logical communication architecture in SVS Laboratory.
Fig. 5. Logical Communication Architecture for SVS Laboratory
As shown in Fig. 5, IEDs in SVS laboratory are engineered and configured to exchange information
between each other in order to execute various substation functions. The detailed functions are
described in Table I. TABLE I
SUMMARY OF COMMUNICATION SERVICES AND INFORMATION FLOW IN SVS LABORATORY IN FIG. 5
Symbol Descriptions
MMS message exchange between IEDs (server) and client applications
GOOSE (Trip & blocking) message exchange between Protection IEDs within bay
GOOSE (Interlocking) message between protection IEDs to Control IED within bay
GOOSE message between one protection IED to another protection IED within the same bay or adjacent bay
GOOSE (Inter-trip) message between Transformer
HV protection IEDs and Transformer MV protection IED
GOOSE (Interlocking – Live Transfer) message between Bus Coupler Control IED and rest of bay Control IED within same voltage level
IEC 60870-5-104 message exchange between Switchgear Simulator Remote Terminal Unit (RTU)
and Human Machine Interface (HMI)
To prove the interoperability using IEC 61850 standard, SVS laboratory applies the multi-vendor
concept where IEDs from 3 different vendors were installed and configured to communicate and
exchange information based on IEC 61850 data models and communication services as per described
in Table I. The IEDs were successfully configured and interoperability using IEC 61850 has been
achieved in SVS laboratory. The detailed information of the IEDs and other devices installed in the
SVS laboratory is described in Table II.
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TABLE II
DEVICES IN SVS LAB
Equipment Manufacturer/
Models
Protection IED Protection 1: NR-PCS 931, PCS 9611, PCS 978
Protection 2 : GE Multilin-L90, F35, T60
Control IED NR-PCS 9705
Automatic Voltage regulator IED Maschinenfabrik Reinhausen (MR)-Tapcon 260
Managed Ethernet Switch RuggedCom-RS 900
Time Server Tekron TCG 02-E
Switchgear Simulator Xenon HMI server
Brodersen-RTU 232 with auxiliary relay contacts
Incontrol Tech-iTec 680 touch-screen based monitor
Secondary Testing Equipment Omicron-CMC 256plus with CMIRIG-B
The software applications that are used in the SVS laboratory are divided into two categories, which
are the proprietary or hardware based applications and independent applications. The list of software
applications is shown in Table III. TABLE III
SOFTWARE APPLICATIONS IN SVS LABORATORY
Proprietary software Independent software
IED configuration tools-PCS PC and Visual SCD for NARI IEDs and Enervista for GE Multilin IEDs.
Client-Server and peer to peer communication applications-Omicron IED Scout
Secondary testing application- Test Universe for Omicron 256plus
Third party IEC 61850 System Configuration Tool-HELINKS STS
Network Monitoring and Management-RuggedNMS for RuggedCom Ethernet switches
Network Protocol Analyzer-MMS Ethereal and Wireshark
HMI design-STRATON HMI Design Tool
As mentioned earlier, one of the main functions of the SVS laboratory is to serve as the platform to
test and verify IEC 61850 compliant devices before they are deployed in TNB system. This is
facilitated under TNB product acceptance process where the IEC 61850 features of a device, typically
IED, are meticulously tested and verified against TNB IEC 61850 requirement. The next section
elaborates the implementation of the product acceptance process and highlights some findings related
to interoperability during the tests.
3. TNB Product Acceptance Process
Starting from September 2013, the SVS laboratory has been utilized for TNB product acceptance
process for IEC 61850 compliant devices, which mostly are IEDs. The significance of having an
internal IEC 61850 product acceptance process is although most IEC 61850 compliant devices have
been tested at independent test laboratories, there is no guarantee that that the devices can interoperate
when assembled together in a system. This is mainly because the tests conducted at independent test
laboratories are IEC 61850 conformance tests, which focuses on the IEC 61850 functionalities of the
devices [7]. Hence, there is a need for TNB to establish a platform to be able to verify the
interoperability aspect of the devices before they are installed in actual substations. Using the existing
IEDs, communication network and testing tool in SVS laboratory, the test setup for the product
acceptance process is shown in Fig. 6.
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Ethernet Switching Local Area Network
TIME SERVER
GPS
CLIENT
DEVICE UNDER TEST(DUT)
NETWORK ANALYSER
GOOSE SIMULATOR
SECONDARY INJECTION TEST
SET
SWITCHGEAR SIMULATOR
IED CONFIGURATION
TOOLS
SCL CHECKER
SCLFILES
CONFIG.FILES
SYSTEM CONFIGURATION
TOOL
IED CONFIGURATION
TOOLSSCD FILE
IRIG-B Time Bus
Control
Statuses
VoltageCurrent
Binary Output
Binary Input
REFERENCE INTELLIGENT ELECTRONIC
DEVICE (RIED)
Fig. 6. Test Setup for TNB Product Acceptance Process
Even with constraints on tools, such as the unavailability of established IEC 61850 protocol
analyzer and traffic generator, SVS laboratory is still able to conduct significant amount of test to
verify the IEC 61850 features and capabilities of an IED in ensuring it’s compliance to the standard
and TNB requirement. Table IV highlights the test cases which are tested in the test procedure. TABLE IV
TEST CASES IN TNB IEC 61850 INTEROPERABILITY AND VERIFICATION TEST PROCEDURE
DOCUMENT AND VERSION CONTROL
1. DUT IEC 61850 Document Verification 2. DUT IEC 61850 Compliance with TNB Requirement
CONFIGURATION FILE
1. .icd File Schema Confirmation 2. .icd File General Content Verification
DATA MODEL
1. Logical Node (LN) Mandatory Objects Verification 2. Logical Node (LN) Mandatory Data Objects/Data Attributes Verification
ASSOCIATION MODEL TEST
1. Client Associations Test 2. Lost Connection Detection Test 3. Startup After Power Interruption Test
SERVER MODEL TEST
1. Quality Bits for Analog Value Test 2. Quality Bits for Status Value Test
DATASET MODEL TEST
Maximum Number of Dataset Elements Test REPORT MODEL TEST
1. Self Descriptions Of Report Control Block (RCB) 2. RCB Trigger Options 3. RCB Optional Fields 4. BRCB Association Test 5. URCB Association 6. Buffering Events 7. Purge Buffered Events 8. Segmented Report
SELF DESCRIPTIONS OF GOOSE CONTROL BLOCK (GoCB) TEST
CONTROL MODEL TEST
1. Direct Control With Normal Security 2. Select Before Operate (SBO) - Positive Response Test 3. Select Before Operate (SBO) - Negative Response Test
IRIG-B TIME SYNCHRONIZATION TEST
SNTP TIME SYNCHRONIZATION TEST
DUT GOOSE COMMUNICATION LATENCY PERFORMANCE AND TEST MODE FEATURE TEST
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1. Secondary Injection Test (SIT) And Device Under Test (DUT) Test 2. Reference Intelligent Electronic Device (RIED) And Device Under Test (DUT) Test 3. Goose in Test Mode Test
CLIENT and DEVICE UNDER TEST (DUT) TEST
FILE TRANSFER TEST
As of January 2014, 12 IED models for 4 different vendors has been tested and approved to be
deployed in TNB. However, regardless of the IEDs having certified as IEC 61850 compliant, issues
related to IEC 61850 functional and interoperability are still observed. Some of the issues are [8]:
1. The performance of GOOSE message for protection tripping was not as fast as declared. This
will impact the performance of protection function if GOOSE is used for tripping. Fortunately, TNB only specifies that GOOSE message is to be used for non-time critical functions such as
interlocking for the time being.
2. IED tested or device under test (DUT) could not interoperate with some IEDs in SVS
laboratory despite of exhaustive engineering and configuration effort. This has raised the
question of the degree of interoperability of the DUT.
3. Capability declaration of DUT in its IEC 61850 documents did not match with the actual
capability of the DUT, such as inability of sending buffered reporting after connection failure is normalized, although the DUTs were from the same vendor but different model. These are
shown in Fig. 5 and Fig.6. Some DUT also showed missing data object and data attributes
although they were declared supported in the documents.
Fig. 7. Vendor X Model A-Buffered reports were not sent after connection failure is normalized
Fig. 8. Vendor X Model B-buffered reports were sent after connection failure is normalized
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4. Certain DUT configuration tools were not able to parse Substation Configuration Language
(SCL) file generated using third party engineering tool. This will restrict the engineering process as users need to fully rely on vendor proprietary for engineering and configuration of
IEC 61850.
5. Unexplained error message generated by DUT was observed during the test for control function.
The control command was successful but the latest status was not updated to the IEC 61850
client simulator. This is illustrated in Fig. 9. Vendor has yet to provide an explanation on this phenomena
Fig. 9. Unexplained “No-error” error observed in Vendor Y DUT when performing control function
6. Significant deviation of DUT timestamp was also observed although the DUT were
synchronized using external IRIG-B time synchronization protocol. The vendor highlighted that it was due to the event sorting method implemented in the DUT that has caused the delay
in time stamping
The above observations have shown that the importance of having an in-house testing facility and
methodology to test IEC 61850 compliant devices before they are installed in the system. This is to
ensure that the implementation of IEC 61850 will not pose unnecessary risk to the system, in
particularly SPACS. Although the issues may look trivial, if they were not discovered and rectified
earlier, there is high probability that they may affect other critical substation functions that may
jeopardize the reliability and availability of TNB transmission network when deployed.
Apart from testing works, the SVS laboratory is also utilize as research and development platform
for TNB to further explore advanced functionalities that can be achieved from IEC 61850 and Smart
Grid domains. The next section will discuss on TNB’s vision to develop in-house software
applications for the operation and maintenance of IEC 61850 compliant substation and systems.
4. Development of IEC 61850 Substation Intelligent Management System (SIMS) in-
house software applications
The SIMS initiative is intended to develop in-house software applications that can be utilized as
operation, maintenance and monitoring tools for IEC 61850 based substations. Unlike commercial off-
the-shelf tools, in-house developed tools are independent from any patent or contract restrictions from
vendors. Hence, there will be no cost impact to TNB in fully utilizing or make any changes to the
tools. Furthermore, these tools are independent from IED vendors hence associated issues related to
IEC 61850 interoperability can be minimized. The overview of SIMS platform is shown in Fig. 10 [9].
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Fig. 10. TNB IEC 61850 SIMS platform
The key elements in the SIMS platform are the software applications which are intended for various
operation, maintenance, monitoring and analytic purposes. In total there are 16 applications which
were developed under SIMS using National Instruments LabViewTM
programming software. Some
notable applications are:
1. Communication Network Management (NetView)
2. Fault and Disturbance Analysis Viewer (FastView)
3. Substation Asset Monitoring (SAM)
4. GOOSE Message Viewer (GOOSEVIEW)
The snapshots on some of the applications above are shown in Fig. 11 and Fig. 12.
Fig. 11. SIMS NetView Application
Fig. 12. Publisher-Subscriber Matrix for SIMS GOOSEVIEW
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The main challenge during SIMS development was the design of IEC 61850 Communication Stack
as TNB has decided not to use any commercially available stacks to avoid any potential restriction in
further developing and implementing the applications in the future. The IEC 61850 Communication
Stack is the heart of all the 16 applications and the SIMS initiative is currently still on-going to further
improve and enhance the stack.
Conclusion
The initiatives implemented by TNB has allowed the utility to have better insight in achieving
interoperability using IEC 61850 which is vital to ensure the successful Smart Grid implementation. It
is also believed an in-depth understanding regarding the key enablers of interoperability should be the
main focus for utilities before embarking in any Smart Grid initiatives. This is to avoid unnecessary
cost implications and technical issues that may hinder the Smart Grid implementation.
References
[1] Zhong Fan, et al. “Smart Grid Communications: Overview of Research Challenges, Solutions
and Standardization Activities”, IEEE Communications Surveys & Tutorials, Vol. 15, No. 1, First Quarter 2013
[2] Mahesh Sooriyabandara, Janake Ekanayake, “Smart Grid-Technologies for Its Realizations”,
2010 IEEE International Conference on Sustainable Energy Technologies (ICSET), 6-9 December 2010, Kandy, Sri Lanka
[3] Xin Mao, et al. “Comparing Smart Grid Technology Standards Roadmap of the IEC, NIST
and SGCC”, 2012 China International Conference on Electricity Distribution (CICED), 5-6 September 2012, Shanghai, P.R. China
[4] NIST Special Publication 1108R2 “NIST Framework and Roadmap for Smart Grid
Interoperability Standards, Release 2.0” February 2012. [Online].
Available:www.nist.gov/smartgrid/ [5] R.E. Mackiewicz, “Overview of IEC 61850 and Benefits”, Transmission and Distribution
Conference and Exhibition, 21– 24 May 2006, Dallas, Texas, USA,
[6] Aminuddin Musa “IEC 61850, Enabler of Smart Substations”, Proceedings of 1st TNB ICT
Technical Conference, College of Information Technology, 21-22 February 2011, Kajang,
Selangor, Malaysia
[7] J.C. Tan, C. Zhang, Z.Q. Bo, “The Importance of IEC 61850 Interoperability Testing”, 43rd
International Universities Power Engineering Conference, 1– 4
September 2008
[8] Mohd Iqbal Ridwan, et al. “Standardized IEC 61850 Product Acceptance Procedure for
Intelligent Electronic Devices: A Malaysian Power Utility’s Experience”, OMICRON 2013
International Protection Testing Symposium, 24-26 September 2013, Boston, Massachusetts, USA
[9] TNB Research Sdn Bhd R & D Project Final Report, “Study and Development of Integrated
and Standardized Engineering Workstation (EWS) Applications for TNB Transmission IEC 61850 Based Substation Automation System”, Revision 4.0, July 2012
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