Advantages of a Protective Relay Network 1

[rockman7892]

We are currently building a new plant in which we will have all of our 5kV feeder breaker relays (Multilin) as well as 5kV Motor Protection Relays (Multilin) on a single network. This network will be tied back to an engineering station which will run multilin software (EnterVista) in order to remotely look at relay diagnostics, monitoring, event reports etc...

Seeing this as being a wonderful troubleshooting and event analysis tool, I was trying to convince the plant to construct such a network for our existing plant which uses a combination of Siemens and Multilin relays. My problem will be trying to convince them to spend the money to implement such a network.

Does anyone have any input to the advantages/disadvantages to using these protective relay networks? Is there anywhere such as a case study or some other paper where I can find information that would shown that such a network would be worth the initial investment?

 

[dpc]

Check the SEL website - they have a lot of white papers on this topic.

"The more the universe seems comprehensible, the more it also seems pointless." -- Steven Weinberg

 

[rockman7892]

Thanks dpc!

 

[JMatt]

I am sure your local Multilin, Schweitzer or ABB vendor rep will be happy to share their respective propoganda with you.

Here's a link to the GE powerpoint on Enervista...

http://www.docstoc.com/docs/2634730/Welcome-to-the-new-GE--PowerPoint-template!

SEL also makes a nice system sold as PowerMax. Of course, any good sales rep is going to tell you that once you get the system installed, there's so much more you can do other than monitoring and troubleshooting. You can do dynamic load shedding, var control, etc, etc, etc.

 

[dpc]

One thing to look out for - I'd strongly recommend synchronizing all of your relays (which are capable of this) to a GPS time clock reference. It may seem like overkill, but when you start comparing fault records from four or five relays for a single fault, you'll appreciate the fact that all have the same time base. If you don't do this, the drift of the internal oscillators used for the clock in each relay can result in some surprisingly high time differences between the relays.

"The more the universe seems comprehensible, the more it also seems pointless." -- Steven Weinberg

 

[slavag]

Hi
What about disadvanteges?
What about troubleshooting of this network?
I told about industries, not about utilities.
Best Regards.
Slava

 

[Eleceng01]

One disadvantage that comes to mind is a cyber-attack. We recently had a large industrial client install Square-D meters (at a high cost) to keep the protective relays off of the network even though the data is the same. The client's justification was "meters can not be used to trip breakers & disrupt the process."

At the least, I would ensure that all of the relay passwords are not the default. I know some will argue that "our network is secure" but IMHO "no network is 100% secure."

 

[dpc]

A network that has no connection to the outside world is pretty secure from outside attacks. That is our normal recommendation for SCADA systems.

The main disadvantage is complexity. Setting up a communications system takes a fair amount of time and effort. And then there will be ongoing maintenance, upgrades, etc. Another problem can be data overload. These devices can produce so much data that it is impossible to sort out what is really wanted. It's important to limit the data transferred to what is really needed.





"The more the universe seems comprehensible, the more it also seems pointless." -- Steven Weinberg

 

[slavag]

Hi.
Dave , Im fully agree with you, SCADA network must be dedicated network ( not connected to public network) and not connected to company internal LAN too, but in this case, we lost a remote control and troubleshooting. For utilities used 101 or 104 or DNP protocol and it another story.

For the industries, problem is maintanance of system (bays, relays)(SCADA, SAS, or what ever). Add bays, relays, changes of interlocks, etc, espesially your application Rockman, I suggest, you have 61850.
You would like add SCADAto exist plnat Siemens and Multilin, are you check FW of exist relays, communication options. It's possible, but not so simple.
Good Luck
Slava