Looking at IEC 61850, Part 2: The Protection Engineer
IEC 61850 is having a moment. Implementations of this series of standards, enabled by intelligent electronic device (IED) technologies that have matured along with modern engineering and test tools, are delivering value in electrical systems around the world. Ever-increasing load, the drive toward smarter grids, and the presence of intermittent, non-synchronous generation are driving power delivery to upgrade, automate, and expand rapidly. In the face of unprecedented challenges, professionals like protection engineers who may have dismissed IEC 61850 before are now compelled to take a second look.
IEC 61850 protocols enable standardized, Ethernet-based communications between IEDs despite algorithmic differences per their various manufacturers. Dramatically less time and material costs are expended when commissioning since singular Ethernet cables between IEDs replace the multiple copper-wired point-to-point device terminations that conventional protection and control (P&C) systems require. Onsite, verifications of IED programming and network connections take far fewer steps than all the wiring checks that would otherwise have to be performed with analog schemes.
Prior to commissioning, digital schemes based on IEC 61850 can be developed in a laboratory which affords the opportunity to iterate until achieving spot-on designs. Not being confined by practical or budgetary limitations that physical wiring presents, protection engineers can create advanced P&C architectures that are virtual, leveraging multi-cast IED communications and other high-speed/low-cost digital technology advantages. Plus, IEC 61850 offers a blueprint for standardization since entire designs become contained in data files that set the communication parameters common in all IED programming in a given network.
So, what does adopting IEC 61850 really entail? In Part 1 of this 5-part series, we looked at IEC 61850 from the relay technician’s point of view with insights from Blake Harris from Doble. This time, I’m sharing what I gathered from two other experts I work with, Ed Khan, Director of Protection R&D, and Bryan Gwyn, Sr. Director of Solutions. I asked them, as protection engineers themselves, to weigh in on a few aspects of IEC 61850 that regard their peers in the industry.
What will change?
Ed: “First of all, the protection engineer needs to be very familiar with the communications. None of the philosophies of protection have changed. You still will do, say, the differential the way you do it. But the outputs are going to be going to a local area network. And the voltage and current inputs to the relay will not be physically wired. Instead, the voltage and current inputs will be in the form of digitized samples carried over fiber optic strands. So, an IEC 61850-compliant relay will have no conventional output contacts and no terminals to receive voltage and current inputs. There will only be RJ45 terminals, or a fiber optic terminal…there is nothing to land your wire on the relay other than these communication cables so you need to know a lot about the communications.”
“The debugging will be different. The technicians should do it, but at this time a lot of technicians do not have the familiarity. First the engineers would have to get good at it – and a lot aren’t yet right now – then that has to get translated over to the technician.”
How’s it going?
Ed: “Depends on the engineer. There is a very muddled-up environment right now. Some don’t like new things and then there are those coming in that do and many of them like IEC 61850. They’re very good with computers, they’re very good with this IT-type of stuff. So, as these young engineers move in, they are the ones who will move it forward.”
“We are seeing GOOSE messaging, which is the station bus part. The other part is the process bus, which converts CTs and PTs to digitized samples. Process bus implementations have not gone too far. The station bus implementations utilizing GOOSE messaging are becoming popular.”
“If they want to progress towards smarter grids, they will have to go with IEC 61850 eventually. How quickly they all go there depends on the population of relay engineers and how educated and skilled they are on that.”
Any struggles?
Ed: “It’s a lot of work. That’s the issue. Some people don’t like it; they want to stay where they are in their comfort zone. They like the stuff that they already have. So, there will be a period when there is a lot of chaos, in my view. And slowly, slowly, if you want to go further you have to go through this chaos to get to a stable environment.”
Bryan: “I think from a protection engineer’s perspective, it becomes more complex because not only do you have to calculate all the settings for a protection relay, but now you have to set up the configuration files to actually configure the network, put all the devices on there … so it definitely has added another layer of complexity.”
Ed: “IEC 61850 … the numbering and the naming is quite complicated. It’s different, all coming from the syntax used by the computing people, so sometimes it’s not very evident what you’re looking at.”
Interoperability?
Ed: “Well, that didn’t happen. The basic argument of IEC 61850 was interoperability between various IEDs manufactured by different vendors. Each company wants to keep the ingenuity of their products. The concept that you can take one IED out and replace it with an IED from a different manufacturer isn’t proven; it will not work. The status now is that with a lot of modifications replacement is possible implying very limited interchangeability. Each company has its own ingenuity it offers. The concept of taking an SCL file and expecting it will work with SEL, GE, et al, to the effect of interoperability…that’s out the window. But, with some modifications, you can make it interchangeable.”
On the outlook
Ed: “It will take time, but it’s not something people will say ‘oh my, I can’t do it,’ no. But it will take time, and it depends on each individual. A lot of small utilities are not entering that field yet, but some big ones are.”
Bryan: “The tools are getting better to enable you to configure and analyze these networks. You’ve got these really good user interfaces that create the networks for you, so that helps. I’m sure the tools will continue getting better and better as time goes on. The engineer definitely needs to have better tools to help get these things installed in a reasonable amount of time and effort, and to reduce the risk of mistakes being made. I think it’s inevitable it will continue to be deployed but it does require an additional skillset.”
I captured these insights from Ed and Bryan on a sort of spur-of-the-moment conversation at a recent conference. With so much information pertaining to IEC 61850 already available online and elsewhere, I wanted to simply hear directly from two professionals I trust to share a few thoughts on the subject. Thank you, Ed and Bryan! Other portions from our conversation will be included in future posts in The Relay™ newsletter.
Check back for Part 3 in this 5-part series where we look at the IEC 61850 laboratory.
Additional Information:
- Originally published in the The Relay™ Newsletter. Subscribe on LinkedIn.
- Learn about Doble Protection Testing Solutions
