Building a new network for the virtualized substation

Power utilities are working hard to prepare their grids for growing power demand, extreme weather events and new reliability and sustainability imperatives. Modernizing the operational technology (OT) in substations is a critical piece of the puzzle.

For most utilities, the main focus of substation OT modernization will be to digitalize primary equipment data through the use of IEC 61850 protocols. Some pioneering utilities are taking a step further by virtualizing protection automation and control (PAC) systems.

This advanced approach will simplify substation engineering and deployments and make it easier to use the latest IT innovations to optimize substation operations.

But utilities have important groundwork to do. To make their digitalization and virtualization investments pay off, utilities will need to rethink and rearchitect their grid communications networks.

Why virtualize substation OT?

OT virtualization is rapidly gaining the attention of utilities because it opens a path to simpler, more agile and more sustainable substation operations. PAC devices such as intelligent electronic devices (IEDs) tend to be vendor specific and have all their key components and capabilities embedded. Utilities resort to complex hardwiring to connect these devices to primary equipment such as current transformers (CTs) and voltage transformers (VTs). This involves lots of effort, resources and cost.

Figure 1: Substation wiring can be complex

Through virtualization, utilities can alleviate the headaches of hardwiring, simplify substation installations and save money. For example, PAC virtualization can enable utilities to:

• Reduce the number of PAC devices they need by 50 percent and more
• Lower PAC operating cost by up to 70 percent by managing functions remotely—no truck rolls required
• Take advantage of the IEC 61850 standards to ensure seamless interoperability between PAC functions from different vendors.

Multivendor interoperability will be essential for unlocking these benefits. In the past, utilities had to interconnect multiple devices from one vendor to execute a given PAC function. Now, with interoperability enabled by IEC 61850, they can model, run, test and validate PAC functions that combine capabilities from multiple vendors before using them in the live grid. This increases availability, strengthens cybersecurity and reduces CAPEX for the PAC environment.

Many utilities are eager to get started with PAC virtualization. Industry groups and communities such as the Edge for Smart Secondary Substation (E4S) Alliance and Virtual Protection Automation and Control (vPAC) Alliance are helping to make it happen by developing open, standards-based virtualization architectures. Their expanding memberships—currently 27 companies for E4S and 34 for vPAC, with many members being power utility companies—show that substation virtualization is a top priority across the industry. 

IEC 61850 drives virtualization in the substation and beyond

Power utilities are progressively adopting IEC 61850 standards as they pursue the ultimate goal of implementing fully virtualized substations. IEC 61850 facilities virtualization by making it easy for primary equipment, IEDs and control systems to interact. With full virtualization, everything in the substation will become a software function. This will reduce the need for physical devices and make engineering and maintenance tasks easier.

The higher volumes and quality of data generated by IEC 61850 communications open the door for utilities to use Big Data analytics, machine learning, digital twins and artificial intelligence (AI) applications to create efficiencies, support predictive maintenance and optimize substation operations.

Utilities can also expand the reach of IEC 61850 and virtualization beyond the substation, for example, by using wide area management protection automation and control (WAMPAC) to make smarter, faster decisions in every part of the grid.

The journey to substation virtualization

How do utilities make substation virtualization a reality? The journey begins in the switchyard and involves four main steps:

1. Digitalize: Utilities must start by digitalizing information as close to the primary equipment as possible. This includes data from CTs and VTs, as well as high-quality data on current and merging sensors from the process bus.
2. Centralize: After digitalizing primary equipment data, utilities can centralize all PAC devices. Since all IEC 61850 devices use Ethernet interfaces and IP protocols, interworking between devices becomes easier. This also leads to simpler, safer and more flexible PAC deployments.
3. Synchronize: Utilities need to deploy a robust time synchronization distribution solution in the substation communication network to support digitalization. An ideal solution will be based on the Precision Timing Protocol (PTP) defined in IEEE 1588v2 and the PTP Power Utility Profile defined in IEC 61850-9-3. This is the foundation of any IEC 61850-based network.
4. Virtualize: The final step is to virtualize PAC functions. Utilities might start by running PAC functions on virtual machines or in containers on virtualized compute platforms. Less-critical functions such as power quality and fault recording could be part of the first wave of virtualization, followed by other functions such as transformer protection and busbar protection, followed by distance protection and, ultimately, line differential protection. 

A network blueprint for virtualized substations

Utilities need a new communication network blueprint that will support these four steps and meet the stringent performance demands of digitalized substations and virtualized PAC systems. The private cloud has a key role to play in this new architecture. Many utilities recognize this and are already extending private cloud networking from the data center to their substations so they can start virtualizing their key use cases.

Inside the substation, the blueprint should include a router and switches that can provide segregated LAN domains for legacy OT, IEC 61850 and IT systems, as shown in Figure 1. The network blueprint must encompass the substation network, wide area network and data center network, and provide resilient end-to-end connectivity. It should also support resilient and high-performance PTP for distributing precise timing across the WAN to PAC systems and other virtualized applications in all substations.

Figure 2: Network architecture for substation OT and PAC virtualization

An ideal network will ensure that utilities have the flexibility to bring innovative technologies such as containers, AI and edge computing into the substation. It will also give utilities the confidence to move core management systems into the cloud while continuing to meet their reliability, resiliency and QoS requirements.

The blueprint must give utilities a way to bring all the substation OT and PAC systems together with the applications that reside in the OT cloud inside the data centers that support them. The best approach is to extend OT cloud networking across the grid, from the substation bus to the substation router, WAN and data center fabric. End-to-end communications will ensure that the protection functions in the substation can work with the application software in the data center to keep the grid running safely and efficiently.

Find out more

Virtualized substations are the way of the future and your network needs to be ready to support them. We have resources that can help you get up to speed.

Watch this webinar to learn more about OT virtualization drivers, use cases, challenges and benefits. You’ll also get insights about how your network can evolve to ease the journey to virtualization.

Read this white paper to find out more about how the IEC 61850 standards can help you virtualize substations and bring greater interoperability, automation and scalability to your PAC environment.