To Process Bus or not To

Author: Marco C. Janssen, UTInnovation, Netherlands

This concept, standardized in the first edition of IEC 61850 in 2004 already encompasses the use of sample value streams and smart messages in combination with a communication network, from the location where the data to be used (measurements and trip and blocking signals) was being generated.

The use of sample value streams and the smart (GOOSE) messages combined with a communication network truly revolutionizes the industry as it no longer limits the functionality to a solution where the source and destination need to be connected in a point to point manner. In a process bus, one source can be connected to as many destinations as required, using one physical network. This means that one fiber based network can replace almost all of the cabling currently used in substations and the potential that such a solution provides does not need any further explanation.

So why hasn't the process bus taken off like a rocket after its introduction in IEC 61850 in 2004? I think there is one simple explanation. The utility industry is conservative, in some cases overly conservative! From experience I know that many engineers have to get used to the idea that there will be no more physical, dedicated, connection for current and voltages, trip signals, blocking signals, etc. This change has created several, most likely unnecessary, hurdles for the acceptance of process bus.

If you read this and think, "well wait a minute, the power system is not some kind of toy to just play around with, and if we introduce something this revolutionary we better think about it" then you are not considering the fact that the IEC TC57 working groups that have developed the process bus concepts contain a large group of very experienced engineers that have very much looked after the possible concerns before even introducing the concept on paper. In this case you also dismiss the fact that the manufacturers that have built solutions around process bus have been in this business for many decades and do understand how the power industry works. The implementation of process bus is not in a trial state, it's a reality!

In my opinion the process bus is one of the truly great innovations in the power industry in decades, as it enables completely new designs for substations, substation control and protection systems and the invention of really advanced new applications to support a smart grid.

Try imagining building wide area monitoring, protection and control (WAMPAC) applications without process bus and the related networks. Do the same for extending substations with new bays and upgrading the busbar protection, the breaker failure protection, the interlocking, etc. A process bus makes these applications so much easier to implement, and in a standardized way. There simply are way more advantages than disadvantages!

What more can an engineer want? Of course, the process bus introduces some challenges such as the isolation of signals, testing of applications and securing safety of equipment and people. However, based on our common understanding of what we want to achieve in these areas, coming up with a solution for these issues isn't rocket science either. Especially since IEC 61850 already provisions for these situations by including test and simulation messages. In other words, we should stop making up excuses and start looking for solutions to use process bus.

The truth is that the main hurdle for the acceptance of the process bus is us, the engineering community! Too often I hear people say that they do not want a process bus because the technology is not mature, or that the solution does not provide the necessary functionality, or that no equipment exists, but these are just excuses in my opinion.

As I already wrote in one of my earlier columns "where there is a will, there is a way" or to add one more catch phrase ""Mr. Do Not Want" is buried in the graveyard and "Mr. Cannot" is buried next to him." In other words, if we want to implement process bus, there are ways to do it and the technology exists to make it happen, however if the will does not exist to do so, there will always be excuses that one can use not to do it.

So, I think that enough excuses have been made, and I invite the engineering community to change its attitude towards process bus and start using it in combination with the incredible amount of intelligence available from the power system engineering community to make the process bus work the way it should.


Marco C. Janssen
graduated the Polytechnic in Arnhem, The Netherlands. He developed further his professional skills through programs and training courses. Marco is President and Chief Commercial Officer of UTInnovation LLC, a company providing consulting & training services in the areas of protection, control, substation automation and data acquisition, and support on the new international standard IEC 61850, advanced metering and power quality. He is a member of WG 10, 17, 18, & 19 of IEC TC57, the IEEE-PES and UCA International Users group.