Nowadays, we worry about robots taking our jobs and becoming smarter than us. But whether we like it or not, the future spells an increasing interaction with machines in one form or another. As this trend intensifies, human machine interfaces (HMIs) will become an ever more important technology for us to master as they will enable us to control and interact with machines.
In this day and age, relations between humans and machines have become rather fraught. A growing number of anxieties crystallise around the use of robots and automation in various industries, not to mention our homes. Things were quite different in the late 19th century, when the introduction of the first machines were expected to relieve people from toiling away for long hours in exhausting circumstances. Families reaped the benefits from time-saving appliances such as washing machines, dishwashers and microwaves as they gradually became mass market consumer goods throughout the 20th century.
While these three letters, HMI, might seem like just another acronym, they are one of the keys to our future world. What is an HMI, exactly? According to one of the broadest and most neutral definitions, it is a user interface or dashboard which connects a person to a machine, system, or device. But HMIs are already used in a wide variety of sectors, from entertainment to medical; and definitions vary according to the various applications and requirements. Interfaces can include motion sensors or speech recognition interfaces, for instance. In other words, what an HMI is and can do depends on what it is used for.
HMIs and the power grid
HMIs are already ubiquitous in electricity generation and transmission, from power plants and substations to wind and solar farms. The definition of an HMI in this context gets a little more specific. According to the glossary of the global standard-setting organisation for the electrotechnical sector, the International Electrotechnical Commission (IEC), it is a “display screen, either as part of an intelligent electronic device (IED) or as a stand-alone device, presenting relevant data in a logical format, with which the user interacts. An HMI typically presents windows, icons, menus and pointers, and may also include a keypad to enable user access and interaction.”
Power grids are modernising 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 visualisation 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 modernise, 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 standardised means of specifying, designing and commissioning HMI applications.
New international standard in the works
But this is about to change. 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,” says 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.
More experts welcome
Many challenges have been addressed during the drafting process. One of them was “to build a consensus between power system experts and graphics/web browser specialists on how best to identify and map a proven graphical configuration language, such as Scalable Vector Graphics, to the IEC 61850 system configuration language,” according to Tessier. One of the key points was getting these two groups of experts possessing very different skillsets to work together and understand each other’s use cases. “The door is still open for other experts to help us prepare and publish the standard – especially graphic editing and web browser subject matter specialists,” Tessier adds.
“The applications for this standard will go much further than digital substations in the longer term. We are looking at the whole issue of artificial intelligence, how it will affect power plants and other manufacturing environments. It involves other areas such as the Internet of Things, for instance. It could even apply to electric vehicles and charging systems,” says Jean Raymond, one of the IEC experts working on the new standard. Like Tessier, Raymond is a Canadian and both report strong support from the Standards Council of Canada in their endeavours.
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 3rd 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 modernise 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 third 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 standardised. 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.
Cyber security is a key focus
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 virtualised substation automation system in the lab. “The first stage of virtualising the HMI and cyber security applications has already been proven,” Vahabi describes. Cyber security aspects are also a key focus of the utility’s R&D effort.
Raymond is aware of the cyber security issues and how important they are becoming as we move towards increasing automation and software-controlled machines. “The IEC will pay increasing attention to the convergence between electronics systems, security and communications as we move forward. This is the fundamental issue to be dealt with, especially as utilities integrate DERs into the grid.”
It may be a brave new and increasingly complex world out there but it would seem that, with HMIs, we have some of the tools to overcome many of these complexities. And the power grid is a great place to start.
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Source: EE plublishers