Series on Digital Secondary Systems Based on IEC 61850
IEC 61850 engineering practices provide non-vendor specific and interoperable methods to configure programmable electronic devices to communicate within a network of interconnected devices. The multiple parts of the IEC 61850 communications standard describe methods for station bus (SB) communications using human to machine (H2M) and client-server protocols to perform tasks including SCADA, reporting, and engineering access. Additionally, the standards describe process bus (PB) communications using machine to machine (M2M) or peer to peer (P2P) protocols to transfer process level signals for tasks including fault detection, interlocking, and protective tripping. To maintain continued support of other existing and future capabilities, IEC 61850 harmonized with work previously done within the Utility Communications Architecture (UCA) IEEE TR 1550 to include IEEE 802.1 Ethernet, object-oriented databases, and compatibility with any other technology through standardization of data processing based on the seven-layer open systems international (OSI) information exchange models. Because of this inclusive standardization, data modeling and protocols within IEC 61850 have evolved over the past 20 years, remain interoperable with methods including Modbus, DNP3, and MIRRORED Bits Communications, and support newer innovations like traveling wave fault location and time-domain protection by design.
All Webinars in the Series:
- Studies of Digital Secondary Systems (DSS) - On Demand!
- Fundamentals of Ethernet in DSS - On Demand!
- Object-oriented Data and Standardized Data Models - On Demand!
- Dataflow Design of DSS - On Demand!
- Engineering Processes for Digitization of Substations - On-Demand!
- Methods to Increase Resiliency of Communications - On-Demand!
- Monitor, Troubleshoot, and Service DSS - On-Demand!
- Cyber Vulnerability Assessment - Mitigation for DSS - On-Demand!
In case you missed it:
Part 1 - Studies of Digital Secondary Systems (DSS)
Presented by: David Dolezilek
This webinar will provide an outline of IEC 61850 methods within the broader context of the digital transformation of energy control systems (ECS). Functionality and communications topologies of several common DSS methods used around the world to replace RTUs and traditional substation wiring practices will be presented. Future webinars will introduce the fundamentals of Ethernet in DSS, object-oriented data and standardized data models, dataflow design, engineering processes of digitization of substations, methods for communications resiliency, and features to monitor, troubleshoot, and service DSS installations.
Part 2 - Fundamentals of Ethernet in DSS
Presented by: David Dolezilek
IEC 61850 engineering practices define packetized Ethernet as a method for defining human to machine (H2M) and machine (M2M) or peer to peer (P2P) protocols. To enable interoperability among suppliers, IEC 61850 describes the use of nonproprietary manufacturing messaging specification (MMS) protocol and proprietary parallel redundancy protocol (PRP) from another standard (IEC 62439). IEC 61850 assures backward and forward compatibility and solution flexibility and durability by enforcing those defined methods co-exist with other methods not defined by IEC 61850 including hardwiring field contacts, nonproprietary distributed network protocol (DNP), and proprietary MIRRORED Bits Communications. IEEE 802.1 Ethernet defines generic connections where messages are published into the Ether, without device flow control, where Ethernet switches use “best-effort” buffer, store, and forward methods to send them toward their destination(s).
In this session we will
• Discuss using Ethernet for DSS messaging
• Understand use of IEEE 802.1p priority and IEEE 802.1Q virtual LAN methods
• Evaluate Ethernet connections, cabling, duplication, and redundancy
Part 3 - Object-Oriented Data and Standardized Data Models
Presented by: David Dolezilek
In the late 1990s, to maintain continued support of other existing and future capabilities, IEC 61850 harmonized with work previously done within the Utility Communications Architecture (UCA) IEEE TR 1550. This included IEEE 802.1 Ethernet, object-oriented databases, and compatibility with any other technology through standardization of data processing based on the seven-layer open systems international (OSI) information exchange models. This third installment of the web series introduces object-oriented data and standardized data models as part of the inclusive information access standardization and protocols within IEC 61850. Because the standard enforces technical co-existence, other methods that have evolved over the past 20 years including Modbus, DNP3, MIRRORED Bits Communications, IEEE 1588 precision time protocol, IEC 62439 parallel redundancy protocol remain interoperable with IEC 61850.
Part 4 - Dataflow Design of DSS
Presented by: David Dolezilek
A Data Flow Diagram (DFD) is a graphical representation of the “flow” of data and is the important preliminary step used to create an overview of the system and is elaborated by another, more detailed DFDs, each more granular, to visualize the complete view of the data flow. Lowest level DFD is the communications protocol diagram (CPD) which shows the protocol to be used and the media. Once all the data sources, destinations, and data flow attributes are understood, protocols are considered to support each flow. Protocol selection considers human to machine H2M or machine to machine M2M, source (standard development organization SDO, standard related organization SRO), proprietary/non-proprietary nature, and cyber defense properties. This fourth installment explains how protocols are often chosen for other reasons and may not support all the attributes identified in the DFDs and so it is necessary to revisit them and the design choices until the requirements are modified to match the protocols.
Part 5 - Engineering Processes for Digitization of Substations
Presented by: David Dolezilek
Digital-based secondary systems (DSS) that are evolving to provide new and better ways to protect and control the primary system, leverage the digital capabilities and resilience of intelligent electronic devices (IEDs) within the secondary system of the energy control system (ECS). First principles of the process level primary equipment, in combination with the utility purpose and focus, support to an organized effort directed at analyzing features, systems, equipment, and material selections. Value engineering principles support achieving essential functions at the lowest life cycle cost consistent with required performance, quality, reliability, and safety. Although best-known methods frequently change as new innovations become available, the underlying first principles of both the power system primary and secondary systems do not change. This session introduces the workflow to harmonize the digitization of P&C standard operating procedures to make best use of added capabilities, information, and detail.
Part 6 - Methods to Increase Resiliency of Communications
Presented by: David Dolezilek
This session discusses Ethernet as best-effort service providing basic packet delivery services without guarantees. It attempts delivery to the destination data link layer but takes no steps to recover packets that are lost or misdirected. To improve resilience of the applications, designers must both add protocol mechanisms at higher levels of the OSI stack to compensate for lost or delayed packets and technologies within the communications network to detect Ethernet faults and take corrective action. Packet management for IEC 61850 protocols are enhanced via IEEE and IEC proprietary and non-proprietary methods and resilience of the communications network is improved by compensating for Ethernet failures within data flow paths. IEC 62439 Part 1 describes resiliency via recoverability methods including spanning tree algorithm (STA) and software defined networking (SDN) without human interaction. IEC 62439 Part 3 describes non-resilient, repairable Parallel Redundancy Protocol (PRP) or High-Availability Seamless Redundancy (HSR) where faults are detected and repaired by human interaction.
Part 7 - Monitor, Troubleshoot, and Service DSS
Presented by: David Dolezilek
Digital secondary systems (DSS) communications includes both station bus (SB) and process bus (PB) communications. Engineering access (EA) is sometimes isolated onto a separate communications bus but it is most frequently merged with other SB communications.IEC 61850 device data objects include essential settings to be reviewed as part of troubleshooting as well as the useful and necessary status and diagnostics of the publishers and subscribers on the PB. Much of the monitoring is done via digital messaging on the SB or EA bus via layer three messaging. When available, the IEC 61850 monitoring logical nodes (LNs) and their contents are identified for use as standardized monitoring data acquisition. These and the remaining essential status and diagnostics must be identified and satisfied as part of the data flow design. This session describes the necessary data objects and their use to diagnose and troubleshoot a non-time synchronized GOOSE PB as well as a time synchronized PB with sampled values and precision time protocol.
Part 8 - Cyber Vulnerability Assessment - Mitigation for DSS
Presented by: David Dolezilek
Modern digital secondary system (DSS) technology uses digital communications for SCADA and engineering access as well as signal transfer among relays and remote digital sensors over high-speed fiber connections to perform fault detection and trip circuit control. DSS systems based on IEC 61850 leverage Ethernet and therefore expose the digital communications to non-determinism and the consequences of shared bandwidth networks. To understand the implications of using available privacy and/or secrecy mechanisms, a cyber vulnerability assessment of each proposed communications design is essential. Many cybersecurity technologies from numerous industries are promoted for use in DSS communications with unknown impacts. This webinar introduces appropriate metrics and a vulnerability assessment framework to compare cyber risks of available technologies to determine the dependability and security of digital control and protective trip circuits. Finally, modern authentication and encryption methods for DSS are introduced in addition to associated international standards.
INTENDED AUDIENCE:
All utility, supplier, and consultant executives, managers, supervisors, engineers, and technicians will benefit from the overview of the use of Ethernet and IEC 61850 in modern protection and control systems
ABOUT THE SPEAKERS
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Tags & Topics for This Webinar:
Digital Secondary Systems, IEC 61850, Ethernet, Station Bus, Process Bus, Digital Trip Circuits, Programmable Electronic Relays, Merging Units, Intelligent Merging Units
AFTER THE WEBINAR IS PRESENTED
For any questions, please contact Phyllis Caputo at p.caputo@ieee.org. To view previous webinars on-demand, visit the IEEE Smart Grid Resource Center |