Third generation substation automation

Power grids are modernizing which allows them to operate in a more efficient and effective manner; HMIs are typically “the face” of this process. The HMI application plays a key role in the visualization and control of substation automation systems or the monitoring of the real time status of a solar or wind farm, for example. Engineers, technicians and operators depend on the information collected and relayed by IEDs to get a clear picture of the state of the substation and the distributed energy resources (DER). These DERs could be wind turbines, a solar farm or a microgrid, for example. As the power grid continues to modernize, the dependency on HMI applications will therefore increase and operators will require help to monitor and control multi-vendor systems.

HMI applications are effectively built upon graphical building blocks such as basic shapes, colours, text, forms or pages to communicate and exchange information. Utilities are increasingly wanting HMIs to work with any vendor IED, requiring minimal manual configurations. A vendor-agnostic solution would simplify installation, reduce maintenance costs and diminish the complexity of power automation systems. It would facilitate the interoperability with multi-vendor IEDs and support data-driven configurations that place the work burden on tools instead of human beings.

Unfortunately, all the graphical components and building blocks that go into an HMI are assembled in a proprietary fashion by HMI software manufacturers. To date, there aren’t any standardized means of specifying, designing and commissioning HMI applications.

New international standard in the works

The IEC is working on a new document which aims to define the configuration languages required to achieve digital substations, including the HMI application. The planned standard, which is currently being drafted, will be part of the IEC 61850 series of publications, which includes some of the core international standards used for integrating digital communication processes into the existing grid.

One of the objectives of the new publication is to automatically generate the HMI application, including all the associated data mappings and graphical renderings. This effectively dispenses operators, engineers or technicians from carrying out a manual configuration of the substation system and therefore saves time and cost for utilities by using resources more efficiently.

 It also removes the risk of human error. “You could call it “magical engineering”: instead of taking weeks, sometimes even months, to configure the HMI applications, it literally will take minutes and even seconds for smaller substations,” describes Dustin Tessier, who leads the task force responsible for the new standard project inside the IEC.

“An HMI is known to be one of the most engineering intensive applications. Automating the process introduces significant savings from an engineering, configuration and testing perspective,” he adds.

Californian high tech

The HMI document is based on a proof of concept technology developed by Southern California Edison (SCE), the primary electricity supply company for most of Southern California. “Unlike many other standards, this document was produced from the ground up. We did not publish a technical report and then a technical specification before writing the standard. We decided to prepare an international standard from the start. SCE had proven the concept so we knew that it was technically feasible to achieve. It is a field where technology is moving fast: we need to make sure we keep track of it so that the standards we prepare are relevant and meet market requirements,” Tessier explains.

For many in the industry, SCE is viewed as a compass: other utilities follow the company’s technology roadmaps and its data-driven HMI application is just another example of its technological savviness. The HMI is part of a 3^rd generation substation automation (SA-3) architecture based on IEC 61850 standards, developed by the company.

Mehrdad Vahabi is one of the engineers who worked on the HMI prototype, as well as SA-3. “Southern California Edison has always been a forward-thinking utility. In 2010-11, the company decided to modernize the grid. While HMIs were already used, they were proprietary which created a number of problems, including cost, the amount of manual work and the time required to make changes to the systems and so on. These legacy problems with HMI were one of the major reasons for moving to 3^rd generation substation automation,” Vahabi explains.

During their research, SCE engineers came into contact with the IEC 61850 standards and their applications for substation automation. “They are a very useful tool set but the HMI part was not yet standardized. We got involved with the IEC experts working on these aspects. They were very open to our project, and we received some extremely positive feedback. We proceeded to implement our prototype in the field and give them information which was fed into the drafting of the new IEC document,” Vahabi adds.

SCE has already started implementing the new HMI in its substations. “The plan is to automate 400 substations with this SA-3 technology by 2028,” Vahabi indicates. Further down the line, the company plans to prototype a totally virtualized substation automation system in the lab. “The first stage of virtualizing the HMI and cyber security applications has already been proven,” Vahabi describes.