b5 Special Report 2012

7/28/2019 b5 Special Report 2012

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SPECIAL REPORT FOR STUDY COMMITTEE B5(Protection and Automation)

Rodney HUGHES (for PS1) and Mladen KEZUNOVIC (for PS2)1

Special Reporters

The CIGRE Study Committee B5 covers within this scope principles, design, application andmanagement of power system protection, substation control, automation, monitoring,recording and metering – including associated internal and external communications and

interfacing for remote control and monitoring.

Two Preferential Subjects are presented in this Special Report:

o PS1: “Impact of Future Network Components on coordination of Protection and Automation Systems”.

o PS2: “Utilization and Application of Remote Access for Protection and AutomationSystems”.

Keywords: Future Networks, IEC 61850, Architecture, Process Bus, Protection Algorithm, Control Algorithm, Asset Management, Setting Management, Data Analysis, Smart Grid, DistributedGeneration, Power System Protection, Automation, Islanding, Power System Stability, Automated Analysis, Cyber-security, Fault Disturbance, Fault Location, Intelligent ElectronicDevice, Metering, Power Quality, Remote Access, Standards, Substation Automation.

CIGRE 2012

B5 - 00



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1 PS1: “Impact of Future Network Components oncoordination of Protection and Automation Systems”

The last thirty years (significantly less than the lifetime of a substation) has seen a massiveswing in the types of technology applied within the protection and control industry. Several

stages of evolution over this time frame has resulted in the single fixed functionelectromechanical devices being replaced by comprehensive multi-function devices nowoperating with ever higher degrees of capability, and even reliance on communicationsystems.

The power industry is now awash with the requirements for driving efficiency,responsiveness and flexibility of the power network whilst delivering higher reliability andlower costs. These drivers combine under the concept of Future Networks that demandsnew solutions which themselves demand new technologies to provide them.

This rapid change (at least in power systems terms) in operational requirements andtechnology solutions is complex and requires a vast range of new skills associated with

systems and communication engineering. Not surprisingly this leads to discussions onmaturity of the technology, or perhaps more accurately, how quickly the vendors bringproducts with uniform compliance and easier interoperability to the market as well as howquickly the market invests in the new skills to be competent in the use of the newtechnology.

This Preferential Subject gives the opportunity to explore both existing and potentialsolutions for how Protection and Automation Systems must continue to evolve to encompassthe new requirements brought as a result of Future Networks.

Specifically the industry has been challenged to present experiences and future directions inthe areas of:

• Local and system wide coordination of protection and control for FACTS / SVC /Power Storage and DER

• Dynamic relay coordination and verification

• Sharing and allocation of protection , control and automation functions

• Communication requirements

Nineteen papers have been submitted providing a comprehensive range of valuableexperiences, not surprisingly with a high degree of overlap between the power systemoperational drivers, the capabilities and management of the devices themselves and thecommunications systems.

Five themes seem to arise from the submitted papers:1. Protection and Automation issues related to design and operation of power systems

2. Modelling, Protection Settings, Adaptive protection

3. Applications / Functions

4. Process Bus: Non-Conventional Instrument Transformers & Merging Units andIntelligent Switchgear

5. Communications, Networks and Information



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1.1 Protection and Automation issues related to design and operation of power systems

B5-103 (Italy) discusses the problems associated with the introduction of RenewableEnergy Resources (RES) into distribution networks in respect of frequency and voltagerequirements. It suggests that these issues are introducing a requirement for decentralised

control systems but associated with hierarchical automation system management to manageoverall dispatching. The particular example includes a Congestion Management system toidentify overloaded lines deep in the distribution system and an iterative process to managethe individual RES to bring loadings within limits.

B5-107 (New Zealand) addresses the concept of changing of distribution network topologyfrom largely radial feeders to meshed arrangements. The new protection system implicationis a reliance of differential or phase comparison protections which naturally would require theuse of telecommunications. It is cited that the advent of Fibre to the Home/Premisesnetworks now in roll out in many countries gives the opportunity for such considerationgiven an analysis of the bandwidth required by the protection services. This also introducesthe issues associated with protection systems potentially relying on leased lines, varying anddiffering propagation delays in different direction and the potential for cyber-security issuesnot just affecting billing processes but directly the performance reliability and security of theprotection system.

DC systems are increasingly being considered for improved management and controlflexibility of power systems. Paper B5-108 (CN) discusses the application of Multi-terminalDC systems, in particular the choice of Current Source Control versus Voltage SourceControl. Modelling of these systems has shown that the interaction and effects of a fault canlast for several seconds.

B5-115 (Japan) describes the need for full and partial Substation Automated RestorationSystems (SARS) using three examples in Japan covering coordination with fault clearance,

fault location and Special Protection Schemes. The paper highlights that significantimprovement in continuity of supply is possible using innovative systems in addition to thetraditional protection schemes.

B5-116 (UK) describes two novel applications for improved power system operation. Thefirst is a Dynamic Line Rating calculation based on inputs from meteorology sensors at thesubstation which determine the variance in line rating. (This is particularly topical in light of the imminent release of IEC 61850-90-3 Technical Report for Condition Monitoringapplications). The second is a mechanism for detection of Loss of Mains islanding conditionsbased on a Phase Angle Displacement calculation between the two systems.

B5-119 (Switzerland) talks about a system using WAMS to estimate system damping in real-

time and based on this allow studies of the expected damping after a disturbance in criticalareas. This real-time estimation of the damping levels across the system can also be used tocontrol power flows using generator excitation, FACTS, etc. in such a way as to improve thedamping and so improve the expected response of the power system.

These six papers present operational conditions covering Wide Area Control for RenewableEnergy Resources, change from radial to meshed network protection solutions, wider use of DC power, specialised SARS, Dynamic Line Ratings, Loss of Mains and WAMS for dynamicsystem damping. Distribution system meshing and renewable energy sources throughoutthe network creates greater challenges due to changing fault levels, bi-directional powerflows, in zone generation, tapped transformers etc. These new operational requirementsmay require more sophisticated protection and control mechanisms based on more thandirect Voltage and Current measurement and derived Impedance and Frequency values.



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B5_PS1-1: What other experiences or possibilities can be presented of these or other protection or automation applications as a result of changing network operation philosophies?

Indeed the protection IEDs are increasingly being seen as the source of vital power systemoperational data suggesting a far more “Utility Automation System” based architecture. TheUAS will encompass traditional protection, control, automation, power quality, revenuemetering, and the new IEC 61850-90 series describes integration of Condition Monitoring,Distributed Energy Resources and even Electric Vehicles. The UAS therefore introduces agreater degree of organisational interaction, system design management anddocumentation. In some areas this will require changes to organisational structure,processes, tools, service provider contractual arrangements and overall responsibilities.CIGRE Working Group B5-391 is addressing documentation practices and there are significantrequirements for improvements in graduate and existing staff education and skilldevelopment as being investigated within CIGRE Working Group B5-402.

B5_PS1-2: What examples can be presented of the type and extent of new organisation, documentation systems and skill developments required to support higher and more integrated UAS functionality?

1.2 Modelling, Protection Settings, Adaptive protection

B5-102 (Germany/Romania) describes the increasing complexity to provide secureprotection settings in ever increasingly complex networks. The paper discusses thepossibility to simulate protection equipment performance over large scale networks withhundreds of lines, buses, generators at various voltage levels and thousands of devices. Thesimulation studies identified that whilst devices settings were applied for the protection of the specific line, several instances can be identified where the fault trajectory remains insidethe operating characteristic of the back-up zone 3 long enough for other lines to trip causingwidespread blackout. Solutions can then be derived using setting changes load blinders andother solutions. The complexities of the modelling are based on reasonable modelling of theoperating characteristic of the protections but not necessarily of the particular protectionalgorithm.

B5-105 (Egypt) describes the results of analysis of faults where some 20% of distance relaytripping was attributed to unknown causes. Subsequent investigations identified thatvariances in the applied k0 factor compared to actual measured values on some 52 cablesindicated the potential for severe under or over reach of the distance elements. The report

identifies a number of different methods for calculating the k0 factor. Further analysisindicated the variation in actual k0 could also be attributable to ageing of the cable itself.The report recommends a comprehensive approach to validating and maintaining k0 settingsrelevant to the actual conditions, also incorporating per phase values and the impact of loadcurrent.

B5-106 (South Africa) discusses the requirements to use advanced protection modelling andsimulation techniques to identify protection application issues in complex grids particularly

1 CIGRE Working Group B5-39: Documentation requirements from design to operation to maintenancefor Digital Substation Automation Systemshttp://www.cigre-b5.org/Site/WG/pa_wl.asp?IDWG=641 2

CIGRE Working Group B5-40: Education, Qualification and Continuing Professional Development of Engineers in Protection and Control.Terms of Reference: http://www.cigre-b5.org/Site/WG/pa_wl.asp?IDWG=642



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those with series compensated lines. Somewhat disturbingly these simulations haveidentified that in some cases, particularly where MOV are used with the series compensationcapacitors, Zone 1 elements would need to be switched off being somewhat counterintuitively against providing high speed fault clearance. The solution suggested uses overcurrent elements to supervise the Z1 element.

B5-117 (UK) describes the testing requirements to prove appropriate response of adaptiveprotection schemes. Adaptive protection is a concept that has been discussed for manyyears but always with a limitation of how these systems are easily tested. The paperdiscusses the range of adaptive protection systems from predetermined Setting Groupsthrough to the potential for dynamic setting calculation. Among the core criteria of protection is security and dependability. Traditional systems were designed with a singlefixed solution or at least predetermined Setting Groups of very precise conditions. Theincreased range of variability based on information provided by communication systems doesintroduce new criteria on telecommunications system reliability and performance on each of the duplicated systems in order to ensure there is no mal-operation of the X or Y system.

This CIGRE forum has often discussed the increasing need for comprehensive system wideand, in some cases, IED modelling in order to optimise protection settings. These papers inparticular indicate changes to traditional Zone 1 and Zone 3 distance protection philosophies.

Of course whether the model is a small section of the power system or a wide area model,the results are only as good as the model of the individual elements of the system. Prior toany consideration of whether IED models are available, accurate models of generators,transformers, SVC, Statcoms, wind farms etc. are often reported as difficult to obtain.

However, such modelling reported over the last several years almost invariably concludesthat traditional 3-zone distance protection is inappropriate in its own right. The solution

often is simply to switch to line differential provided a suitable telecommunications link isavailable, which in itself is far less of an issue than say 30 years ago. This then challengesthe cost/benefit justification of system/IED modelling if the general objective is primarily tovalidate distance protection based systems, versus the “obvious” simplicity of the linedifferential solution. As the networks become more complex, it remains to be seen if changing utility policies signal the end of the era of the distance relay as the generaltransmission protection technology.

There is already a wide body of experience of modelling these new power system elements,arguably the precursors to the formal concept of Future Networks, which confirm there aresystem wide phenomena that haven’t existed previously. This suggests the purpose of modelling is likely to change from purely validating a specific distance relay setting to more

control related issues where wide area automated control systems may be required. This isalready happening to some degree at the transmission level as reported in the papersgrouped under the first theme of this Report.

The sub-transmission and distribution networks are also changing from “simple” radial supplysystems to more meshed systems, embedded generation, 2-way power flows, variable faultlevels and many complexities associated with Distribution Automation Systems withautomatic switching and restoration. This may lead to complex modelling requirements of distribution networks and indeed may have results that reflect to the transmission network models.



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B5_PS1-3: What examples can be shown of the cost (effort)/benefits justification of wide-area/multi-voltage system modelling leading to alternative individual protection solutions or generic policy changes?

Two of the fundamental requirements for protection systems are Security (not operate whennot required) and Dependability (must operate when required). Traditional fixed systemdesigns have therefore provided appropriate solutions to both these requirements but areincreasingly giving cause for concern as the networks do become more complex themselves.Due to the inherent dynamic behaviour, it is much harder to verify correct performance andpotential settings of “on-line adaptive” protection and control systems under all operatingconditions. This is further affected on the reliance on the communication systems (local andwide area) and their effect of failures on the protection system security and reliability.

B5_PS1-4: What other examples can be presented of ‘on-line adaptive’ protection or control solutions along with the necessary mechanisms to validate their dynamic behaviour?

1.3 Applications / Functions

B5-101 (Romania) identifies that line differential protection schemes are a well-knowncommonly used method for minimising power system disruptions. Phasor MeasurementUnits are relatively new devices in the substation which identify the individual currentphasors. These PMUs can therefore be used as the basis of the current differentialprotection and can provide some enhanced security with adaptive algorithms. A possibleimplication of the use of ‘raw’ phasor values is that the proprietary current differential andtime synchronisation processes may be possible in the future to be replaced with generichardware which is not constrained by requiring the same manufacturer of IED at each end.

B5-104 (Argentina) discusses the Argentine experiences of reviewing the performance of 20-year old WAP and WAC systems compared to modern system requirements. As thenetwork has evolved the requirements have changed from a radial system to a meshedsystem with significantly different characteristics that will demand different WAP and WACphilosophy. The paper leads to the potential for PMU and the need for sharing of IEC 61850GOOSE information between substations. The paper suggests a 5 stage process toevaluation of new requirements and available solutions.

B5-113 (Canada) provides a summary of the activity of the IEEE Power Systems RelayingCommittee Working Group K5 "Ancillary Protective and Control Functions Common toMultiple Protective Relays”. The WG is dealing with the issues for implementing certain

substation functions where duplicated systems may be involved, such as initiation of acommon or duplicated breaker fail function, common or duplicated auto-reclose function oreven just multiple disturbance recorder capabilities. The paper also identifies other aspectsassociated with operation/testing and ultimately even the documentation of these functions.

These papers highlight the potential for changes in the traditional protection and controlsolutions. This largely enabled by the availability of high speed communication networks andIEC 61850. Part of the consideration of new systems must be on the reliability requirementsleading to potential duplication of these systems or some redundancy mechanism to ensureon-going operation of the power system



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B5_PS1-5: What other examples can be shown of “real-time” / automated protection control requirements and solutions using PMUs?

B5_PS1-6: What existing or future solutions, and resulting benefits, arise from

the use of IEC 61850 in providing advanced and possibly duplicated or redundant wide area and local protection and control solutions?

1.4 Process Bus: Non-Conventional Instrument Transformers & MergingUnits and Intelligent Switchgear

B5-110 (Spain) elaborates needs to build new substations more efficiently (time and cost)from material end engineering view point. Using optical fibre connection and IEDs related toswitchgear including merging units for instrument transformers are being advocated. It alsodiscusses range of applications on substation and control centre levels to enable network optimisation and to facilitate grid operation and stability. A single communication standard

IEC 61850 has been identified as key technology to facilitate efficiency efforts from utilityenterprise level.

B5-111 (USA) describes the requirements of a calibration system for proving the accuracyof phasor measurement units including the primary sensors.

B5-112 (USA) The paper describes the use and experience of Rogowski coils on an electricarc furnace application. The advantages of Rogowski coils is described including size,linearity, no saturation, and summation (no saturation) whilst providing the necessary speedand selectivity even in the presence of harmonics and transformer energisation inrush.

B5-118 (UK) describes the methods being used to evaluate IEC61850 9-2 for use on theUK's 400kV network. The paper details how the network architecture was selected using

reliability and cost analysis. The effects of network load were then considered and testedhighlighting the need for effective traffic management.

These papers indicate that Sampled Values and Non-Conventional Instrument Transformerscontinue to attract a lot of interest but wide spread deployment is slow. Some schools of thought suggest that the move from “wire based” substations to adoption of IEC 61850 andthe broader concept of a fully digital substation will only be fully justified when this ‘apparentlack of maturity/availability’ is resolved. Certainly there is a demand for case studies dealingwith performance comparisons, cost/benefit justification, application lessons learned,associated technology (e.g. Time synchronisation 1PPS/IEEE1588-C37.238), general

specification and integrated interoperability testing requirements.

B5_PS1-7: What examples of Sampled Value CT/VT applications can be described that would indicate this area of technology is both technically and commercially viable and available?

On the broader scale of Process Bus covering all interfaces to primary systems such asintelligent Switchgear, Condition Monitoring and even the specific Logical Nodes associatedwith Wind Farms, Hydro Power Plants, Distributed Energy Resources all suggest much largersystems will evolve with specific protection and control functionality becoming just oneamongst many applications essential to the operation of Future Networks.



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B5_PS1-8: What are the benefits and requirements for replacement of hard wired trip signals to the switchgear (IEC 62271-3 interfaces) as a complete “digital substation”?

1.5 Communications, Networks and Information

B5-109 (Spain) describes the redundancy of substation Ethernet communications networksin order to maximize system availability and reliability. Device level and system levelredundancy are considered for the communications network and the substation automationsystems at station level. Consideration is also given to recovery from hardware failure andthe effects on the concurrency of data in automation or SCADA databases, along with aproposed solution to this problem.

B5-114 (Brazil) describes a system proposed to optimise data flow through all levels of theinformation hierarchy, starting from the IEDs through to high-level SCADA and asset

management systems as used by a national grid operator. A Data and Information Structure(DIS) is described that is intended to minimise the number of measurements made and theamount of data that must flow in the communications systems and still provide all therequirements of all functions that require data.

Availability and security of data communications is critical to the operation of these modernschemes and is not surprisingly a common aspect across each of the four previous themespresented in this report.

Traditional protection systems have generally been implemented as fully duplicated andsegregated systems allowing one system to be partially or fully out of service without loss of

overall functionality.

These new communication system capabilities provide a means to focus on Availabilitycriteria as a measure of the likelihood of the system to remain in operation. This is based onidentification of failure modes and continuity of the function by redundant common or dualnetwork mechanisms not necessarily relying on fully segregated duplication. Thevirtualisation of functions and their inputs/outputs via communication networks provides newopportunities for increased reliability using bump-less paths and even dynamic functional re-allocation amongst IEDs (hot stand-by spare IEDs) on the network. Naturally thesecapabilities require different investments in the communications equipment, the IEDsthemselves, the configuration of the system and the facilities that support maintenance andtesting.

Network architectures and functions must therefore be analysed for the applicationrequirements and cost/benefits for the use of RSTP/PRP/HSR communications redundancysystems rather than fully duplicated and segregated protection and communication systems.

B5_PS1-9: What processes and results can be presented of the analysis of availability, reliability, redundancy and duplication requirements of functions and networks?

B5_PS1-10: What new facilities, equipment, tools and procedures are necessary for operation, test and maintenance of communication based systems?

The change from wire-based to digital systems introduces new considerations of what may

be considered as IED and network device failure modes, identification and treatment of ill



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formed/corrupt messages, virtual interconnection of previously duplicated and physicallysegregated systems, and even cyber-security interference with the system.

CIGRE has produced two previous Technical Brochures3 dealing with cyber threats and has afurther Working Group B5/D2-464 identifying cyber-security measures as parts of theprotection and control specifications and designs.

The IEEE 1686 Standard deals with application of Role Based Access Controls as part of equipment procurement specifications. However this can only work if supported byappropriate governance procedures associated with staff joining and leaving the organisationand its contracted suppliers as well as device level procedures for changing default access.

The Stuxnet virus has demonstrated that messages can be spoofed or replaced to appear asvalid system messages or even change device configurations. “Virtual Perimeter Intrusion” systems generally deal with access to the LAN as discussed in Preferential Subject 2.However the sub-millisecond, real-time, minimum latency, peer-to-peer operation of theprotection systems require appropriate mechanisms to identify cyber attacks against the safeand reliable operation of the system. IEC 61850 does have various capabilities in relation to

message integrity (sequence, source health and quality) and identifying changes toIED/network configurations; however these new requirements must be specified by the assetowner and implemented by the systems integrator.

B5_PS1-11: What corporate governance measures and system functionality are being deployed to identify and control potential cyber interference with the peer- to-peer real-time operation of the protection and control systems?

Alarm handling, filtering and drill-down has been a focus of attention for system operatorsfor many years as the number and types of available data points has increased. It is notuncommon for utilities to report 5-10 fold increases in SCADA data points alone over the last15 years. As intelligent devices become more prevalent and move from proprietary systems

to being more fully and directly integrated into the Substation Automation System, theextent of data will expand even further. The new IEC 61850-90 series identifies applicationswhere “the system” will encompass many new applications and data. As an example IEC61850-90-3 identifies amongst several Condition Monitoring applications, some 155 DataObjects, and therefore hundreds of attributes, associated with various transformer sensors.

B5_PS1-12: What other philosophies, policies and mechanisms can be described for effective data collection/collation and presentation as information across the Utility Automation System?

1.6 PS1 Conclusion

Protection and automation systems have evolved over many decades to be generallyconsidered as "good industry practice”, arguably derived from many bad industryexperiences! On the other hand, community and industry expectations for Future Networksdemand even better solutions.

The challenge for Protection and Automation is therefore to identify the nature of the newpower system operational requirements and provide appropriate new solutions whilst not

3 CIGRE Technical Brochures: www.e-cigre.org 419 Treatment of Information Security for Electric Power Utilities (EPUs)427 The Impact of Implementing Cyber-security Requirements using IEC 618504

CIGRE Joint Working Group B5/D2-46: Application and management of cyber-security measures forProtection & Control systemsTerms of Reference: http://www.cigre-b5.org/Site/WG/pa_wl.asp?IDWG=652



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forgetting the fundamental principles that have guided safe, secure and reliable powersystem operation to date. This requires an open mind to the new requirements and awillingness to investigate how the new technology will provide even better results than wehave previously achieved.

The papers submitted in response to this Preferential Subject cover a wide range of issues

that will serve as a good reference in their own right. Certainly there are dozens of mattersarising which can be further described in response to this Special Report.

2 PS2: “Utilization and Application of Remote Access forProtection and Automation Systems”

The remote access to substation automation systems is a relatively new development thathas taken place for obvious reasons of being able to upload data from substation IEDs andchange setting in relays and other IEDs doing it all from offices away from the substation.The concept of remote access is further developed to accommodate and utilize unique

features of modern IEDs expressed through multifunctional capability for data management,as well as advanced communications. The need for cyber-security and standardization of thesubstation communication and remote access procedures became more important than everbefore. What is new is the ability to do it in a standard way using one set of communicationprotocols and procedures, as well as automating it to the extent possible. As a result of thisnew development, several applications previously done with many different software toolscan now be somewhat simplified and unified allowing for interoperability of remote accessapplications. While we are still not at the point where standardized approaches to remoteaccess are a prevailing practice, certain uses of the remote access are quite frequent:

• The SAS data may be uploaded and analysed at remote sites for many purposes

• Settings in substation IEDs that are part of SAS may be updated from a remote site• Maintenance and diagnostics function may also be done through the remote access.

Particularly remote access procedures for performing automated analysis of fault anddisturbance data and remote change of IED setting seem to be exercised in several utilitiesaround the world. Related CIGRE activities such as the 2003 Colloquium in Sydney (PS#2: Automated Fault and Disturbance Data Analysis) and Technical Brochure reporting on thework of WGB520 (New Trends for Automated Fault and Disturbance Analysis) illustrate suchefforts.

This part of the Special report raises a set of questions stimulated by eleven papers

submitted by the authors from ten countries (Belgium, Brazil, China, Egypt, France,Germany, Japan, Mexico, Switzerland and USA). The papers are written by either utilitycompany alone (three) or in combination with a vendor (four), or various combinations byvendors, consultants and R&D institutes (three), and in one case by a university incooperation with utilities and a vendor. This represents a very good mix of various viewstaken from a different perspective. The papers cover many topics, for this purposearbitrarily grouped under four broad categories:

• Application requirements,

• SAS Solutions Using IEC 61850,

• Cyber-security issues

• Standardization



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Almost all the papers make reference to IEC 61850 requirements or design features except afew involving utilities that did not have 61850-based installations available yet. For eachcategory, an introductory discussion points to the main trends expressed in the papersfollowed by the questions raised by the special reporter. The questions relate to both theissues raised in the papers and the ones formulated in the PS2 call for papers.

Since some papers submitted for this session address several topics from the list above,questions raised in this report may refer to the same paper multiple times when discussingvarious topics.

2.1 Application Requirements

Two papers coming from utilities, one from a vendor and three with multiple co-authors fromutility and their R&D organization, vendors and a university are focused on the requirementsrelated to specific application of remote access to the digital fault recorders and protectiverelays.

B5-201 (Egypt) raises an interesting question whether stand-alone digital fault recordersshould be used in addition to more integrated SAS solutions such as the one supported byIEC 61850. The fault analysis studies illustrated in the paper demonstrate unique recordingrequirements that may not be met through the current product offering under IEC 61850.

B5-205 (France) explores the “non-real time” applications of the remote access andelaborates on future needs and plans for the use of non-operational data. Besides thecommonly mentioned setting coordination and event analysis needs, the paper also mentionssoftware version and asset management as the applications worth exploring.

B5-206 (USA) looks at the overall opportunities of using non-operational data foroperational purposes and introduces several applications to illustrate the potential of suchuses. The prior experience with automated analysis of non-operational data indicates thatfast processing and result dissemination allow users to take full advantage of the extractedinformation in performing real-time operational decisions.

B5-208 (Mexico) emphasizes the need to have versatile remote access features that mayserve different utility groups reducing the time to physically access remote substations thatmay be several hours away from the main offices.

B5-209 (Brazil) focuses on digital fault recording and discusses how such data may beutilized today and in the future. The focus is on automated fault analysis and opportunitiesto use relatively new dedicated IEDs such as Phasor Measurement Units (PMUs) to enhancethe analysis.

B5-210 (Japan) co-authored by utilities and vendors elaborates on the remote accesshistory, present practice and future plans for connecting protective relays. It has beenrecognized that this technology has matured over the years and now serves multiplepurposes such as relay diagnostics, setting management and event analysis.

As a result of the various application requirements and solutions discussed in the papers,several questions regarding some specific application issues have been identified below.



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B5_PS2-1: What the issues are when integrating data from IEDs embedded in 61850 solutions and standalone recording systems consisting of digital fault recorders?

B5_PS2-2: How automated event analysis solutions may be transported from one

generation of fault disturbance equipment to the next without major redesign or additional investment?

B5_PS2-3: What specific type of asset and software version control management applications the user should embrace to take full advantage of the remote access capabilities?

B5_PS2-4: How one deals with large number of relays (hundreds and potentially thousands) if failure monitoring and setting coordination are to be managed through remote access?

B5_PS2-5: How the IED triggered non-operational data can be integrated with real-time scanned (SCADA) or streamed data (PMUs) for operational purposes?

B5_PS2-6: What other experiences of remote access applications are and how 61850 may be used to solve various application issues of remote access?

While this section focused primarily on the application requirements for the use of theremote access and utilization of SAS data, the next section deals primarily with the papersand related questions on the implementations using IEC 61850.

2.2 SAS Solutions Using IEC 61850

The focus here is on how the remote access needs may be met by implementing solutions

that take advantage of the IEC 61850 design principles. These papers examine many

different aspects of the IEC 61850 solution implementations as discuses next.

B5-203 (France, Germany and Belgium) looks at requirements through several use cases

and concludes that the requirements should cover the interfacing between SAS and SCADA,

SAS and Engineering offices, SAS and Protection engineers, and SAS and Wide-Area

solutions.

B5-204 (China) describes a master/slave system designed to coordinate remote accessbetween the centralized location and distributed SAS. Special attention was paid to the

integration between IEC 61850 and non-IEC 61850 devices and protocols and their

integration. In that context the semantics of the IED data is extended to overcome some

perceived IEC 61850 constraints.

B5-211 (Switzerland) focuses on tele-monitoring aspects of the remote access. It has been

recognized that many remote access applications have been in service for a long time but

the uses of SAS as a complex Remote Terminal Unit of a SCADA system is rather recent.

As a result several questions about specific implementations of IEC 61850 based solutions

are discussed next:



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B5_PS2-7: What communication channel Quality of Service (QoS) and SAS processing latency is to be expected for various types of users and applications that utilize remote access?

B5_PS2-8: How the semantic correlation between SAS and SCADA data should be

defined and maintained understanding that the objects description may undergo changes over time? B5_PS2-9: If the remote access is used in addition to classical remote control interface, how the interaction between the two should be managed?

2.3 Cyber-Security Issues

Cyber-security becomes one of the main concerns when remote access is proposed orimplemented. Almost all of the papers made reference to this issue and offered some

insightful observations and solutions. Two papers in particular (202 and 207) have beendevoted to this subject almost entirely, and several other papers touched upon this issue,205 in particular.

B5-202 (Germany) gives an overview of cyber-security issues related to remote access andoffers some advice regarding hardening of the solutions. The Ethernet protocol with IPaccess is considered a standard solution in the future. The proposed solutions containcyber-security measures embedded in the devices as well as at the communication levels.

B5-207 (USA) addresses a secure communications between SAS and the rest of the utilityusers. It proposes a pro-active cyber-security life-cycle model to assure that all aspects are

correctly designed and possible changes anticipated ahead of the time.

B5-205 (France) talks about importance of cyber-security and suggests that cyber-securityis implemented using secured gateways and security server.

The discussion in the papers leads to the following questions:

B5_PS2-10: How the physical and cyber security protection policy needs to be implemented to prevent vulnerabilities to both cyber and physical compromises of the remote access?

B5_PS2-11: What the best guidelines for designing a proactive cyber security model are, particularly what standards besides CIP 002-009, IEC 62351 and NISTIR 7628 are recommended for the remote access?

2.4 Standardization

In several papers IEC 61850 is mentioned or an IEC 61850-based implementation isdescribed. While the use of IEC 61850 substation SAS standard is widely spread and prettywell documented, several issues still remain unanswered. Some papers also mentionedextensive use of COMTRADE standard for transient data representation. It would be

interesting to know the extent of use of other similar standards. It was somewhat surprisingthat the use of remote access to communicate GPS synchronization signal according to the



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IEEE Standard 1588 (profile C37.238-2010) has not been mentioned by any of the papers. A few papers mentioned the need to resolve data semantics incompatibility between IEC61850 and IEC 61970.

Based on the discussions in the papers the following question is raised:

B5_PS2-12. Is the IEC 61850 standard fully specified when it comes to high resolution recording triggered by faults including the time stamping, sampling rates and data formats?

2.5 PS2 Conclusions

Based on the ideas presented in the mentioned papers and related questions, the followingconclusions regarding the remote access may be drawn:

• Application requirements. Many examples of the applications that can benefit

from the remote access are given. It remains to be seen whether the standardsolutions based on IEC 61850 and other prevailing standards can accommodate allthe needs;

• SAS solutions using IEC 61850. This prevailing SAS communication standard hasmany advantages that are illustrated in several papers when it comes to remoteaccess. The implementation of the transfer of GPS time-synchronization signal froma remote site, cyber-physical security policy and requirements for time stamping andhigh resolution recording remain subject for further implementation evaluation

• Cyber-security issues . The remote access has become of particular concern whencyber-security issues are considered. Many practical solutions that can remove such

concerns exist but life-cycle model and standard recommendations are not widelyavailable.

• Standardization. A major requirement for standard solutions is that they meetinteroperability criteria. The remote access assumes that interoperability betweenSAS systems and solutions that are provided at the remote site are met. It is notentirely clear what are the best practices for achieving interoperability of end-to-endsolutions.

b5 Special Report 2012

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