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Relay & Control Panel Cost Reductions Project 16

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jlgordon

jlgordon

Electrical
Dec 27, 2002
7
US
Are there any other utility engineers responsible for finding ways to lower substation costs for 2003. I have been authorized/ordered to throw out our 100+ years of relay panel standards and start over with a clean sheet of paper on a new design for our relay, SCADA, and control panels to be built in the future. Not wanting to reinvent the wheel, I thought I would begin with switching from our custom everything to more off the shelf components. Has anyone blazed this trail already and if so, what are some of the problems to look out for? Our substations are used to serve both areas of large cities to rural farmlands in Texas using votages ranging from 12kV to 345kV. I have been authorized to utilitize microprocessor based relaying for both transmission and distribution class subs, versus the old Electro-mechanical relays. We have used one of the more common microprocessor brand relays for distribution class subs for the past eight years. Management wants even more savings. So starting in January my standards are gone and an empty white paper will be staring me in the face. All ideas are welcome, extremes included. I will even have a budget for prototyping and testing in a lab so "reliability" will be maintained. What are the most economical panel designs? We currently use 19" rack mount for distribution class relaying and custom punch steel for transmission class relaying. Is there anything else more economical? We are looked at having turnkey systems manufactured by switchgear manufactures to getting ride of our steel fixtures the breakers are previously installed with to pole mounted reclosures with a control box on the opposite side with all the relays.
 
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Suggestion: The newer type of integrated relaying can be accommodated differently than the electromechanical relays. It will consume less space even if redundancies of highly integrated protective relays are considered.
 
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To some degree, reduction in capital-equipment costs need to be offset by appropriate (re)training costs.
 
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jlgordon,
the company I work for also used to make their own relays components. Now we make practically nothing, we buy everything. My company also used to test in the laboratory everything we used in the substations. Now we test everything at site during commissioning. I won't discuss relay manufacturers, other companions have done that.

I can state that you may find issues with maintenance. For example we used to have a unique company number for each secondary relay asset. Now we use the product manufacturer's number.

You may find issues with your relay data base, about how to store the new relay settings. Do you store every single configurable point, or only the ones you use in the new relay? Or do you just store the relay settings as a file attachment to your electronic relay settings data base?

ReTraining may be found to be a big issue also.

Benefits: when a transitory fleeting fault occurs, you have some hope of capturing the event and post fault analysing it!!! You get a fault locator that can help you find the location of a fault along a transmission line of sufficient accuracy to be beneficial to your linesmen.

SCADA relay interfacing. You can use DNP3.0 or ethernet type connections to your relays. Ethernet means you can access your relays easily through your computer back in the office, but then there are firewall issues. Talk with your IT people, but be sure they don't take over your substation LAN work!
You could use DNP3.0 for now until the ethernet protocols are more robust.

There are my brief thoughts, hope they help!

cheers
 
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I have found the ABB Ref543 relay to be excellent. It has hundreds of protection functions as well as metering etc.

Well worth having a look at.

Best of luck in you Herculean task!
 
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I totally recommend you to check SIEMENS 7SJ63 relays. They have many protection functions and they also have logic functions in order to make switchgear interlockins. It is also possible to control circuit breakers, earthing switches etc. Everything is in one relay.
 
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My advice would be to check the Alstom MICOM products. They offer digital protection functions as well as serial communications options (Courier, DNP, IEC etc.) They are also relatively CHEAP - the ABB REF543 relay mentioned above is an all singing, all dancing product but maybe 10x the price of a basic MICOM relay, if all you require are basic protection and SCADA type functions.
 
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Thanks for all the input so far. Yes, we agree with all your suggestions. We have been evaluating different relay mnf's. product lines for a while and are planing on bringing in some of the ones mentioned above. Additionally; we want to go the next step and look at the whole cost; both initial and long term. For example, we want to look at how the relays are physically put into service. Are there less expensive methods of physically mounting/packaging/putting relays into service without increasing service interruptions and maintenance costs? We have always had everything custom made to our perceived stringent needs, ignoring the rest of the world and their practices, (ie: we use the green wire for trip circuits versus the ground circuit.) We use special termination points for all cable wire tie points that allow easy circuit interruption. Can we switch to more common items that are more "off the shelf" in nature and still maintain longevity and reliability while reducing lead times and costs? I just found out that a project budgeted for last year was not started because of a 40A DC bkr has not yet been delivered even though it was ordered back in August. The job is critical as it replaces a DC source that contractual terminated at the end of the year. Why have million of dollars tied up in our warehouse for equipment that may or may not fail? We want to be able to send our field personal to a local business that has what we need on their shelf for immediate purchase when something fails. Not pay taxes on equipment sitting in a warehouse that eventually is just thrown away on the next warehouse cost reduction initiative.
 
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jlgordon -
Sounds like an engineer's dream project in a lot of ways.

Along with many other activities, I have been involved in designing/constructing P&C panels for many years. My present "standard" design, distilling the experience of these years, centers around 19" rack accommodation of microprocessor relays. A typical panel (41 rack units high) can accommodate two transmission line protections (duplicate distance protection - 138 kV in this case + metering), or two transformer protections (differential + overcurrents + metering). This density saves considerable real estate. Modular panels ease the assembly process and allow flexible mounting.
Standardized test switch facilities (again 19" rack mounted) and rail-mounted terminal blocks contribute to the increased density. I have also worked with the "connectorized" removable wiring connectors offered by SEL, which replaces the conventional test switch concept.

I think that your cost savings will mainly result from minimizing wiring and space requirements - both areas where microrocessor relays will help.
 
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Peterb follows much of what I have found. A lot of the cost is tied up in the wiring itself, and not so much on the hardware. By using multi-function relays you can eliminate a lot of hardware AND potential for misoperations. This will also dramatically reduce the hardware costs and wiring costs.

Use intelligent devices that can talk directly to the SCADA system. This will eliminate most of your transducers and interposing relay panels. You'll also get redundant readings for the same data points so you can cross-check the accuracy of data you're gathering. Watch out for data overload doing this, as you'll be able to gather information you'd only dreamed about before.

I'd also look at your control switches. Some utilities wire them into the RTU/PLC in the substation and not between the equipment in the substation. Pros and cons to doing this. Simplify the wiring as much as possible.

Mark in Utah
 
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I would recommend SEL relays. We have been able to eliminate transducers for SCADA, control switches, panel metering, reclosing cutoff switches, interposing relays etc. In addition all SEL relays and communications devices use the same protocol for communications. The nice thing is that they do not require specific software to communicate with the relays. You can use the SEL software or you can use Hyperterminal or Procomm and once you learn to talk to one, you can talk to all of them. Only the settings change not the commands. The Oscillography available in most of there units can even replace digital fault recorders, oscillographs, and sequence of events recorders.

Talk with them, they can save you a bundle and still provide the quality and reliability you are looking for.
 
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I've done a few of those jobs, the best way I have found is to have pre-engineered Panels built to replace the old ones. These panels only take up about a third of the room as your mech. relaying panels do. So you can plan your outage time around the wiring that is done to intergrate the new relaying and phase out the old panels a section at a time. Reducing the total outage time. The change over to Multi-function Relaying is a smart move, the relays that GE and SEL puts out are amoung the best. Learning the software is easier with the GE, but SEL has great tech support and more expertise in the field of multi-function line relaying.(SEL)= Schweitzer Engineering Laboratories. Electrical Power Solutions Ltd.
 
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Have you thought of using web enabled interfaces, putting them on the Internet and looking at them with a browser? This seems to be the most inexpensive way of implementing a man machine interface in this century. . .
You may care if the casual browser can see what's going on as long as they couldn't 'get at' anything (via programming passwords and so on).
If I were to design a modern SCADA system that is how I would do the MMI.
 
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Whichever relays you choose to use, make sure the eng comms protocol is not a proprietary one. The cost of getting converters can be very high or impossible. Also consider what is needed to download / upload settings and records. Do you have to pay for the software?

 
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A thought before you throw out that "100+" years of standards. You are still going to have to deal with the "backbone" of the previous 100+ years at your existing and new installations: Cables. While minuraturization and multiplexing of information has created opportunities and necessities for space reduction, I havn't seen any complimentary improvement regarding control cabling size reduction, routing, and termination requirements. Conversly, I have seen an increase in the amount of cable terminations within a reduced termination space using reduced size terminal blocks. This has been observed as a "glob" of wires with labeling that cannot be read or traced back to an entering cable or panel device.
 
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Oh dear, 15 years ago I would have, and did agree with the management stance. "Let's move forward and invest in new technology" Now I would say why scrap a perfectly good backbone system. 70% of our network was re-populated with MIDOS relays. Now I am receiving obsolescent notices from Alstom nearly every week. So we invested in REF5xx series of relays. Over priced, over complicated, complex comms set up. Failures as long as my arm, two of which lost our whole system ! So now we are moving onto Siemans kit which seems to be a good direction to go. I hope....

When I walk into a sub and see an electromehanical relay I know its a) 25+ years old, b)reliable, c)repairable d)maintainable and doesn't cost me anything.

Think carefully and popoulate your system with new technology carefully.

PS The MICOM comms system doesn't work to the C922 I believe they have scrapped the i/f design.

I'd buy a large cork too......:)



 
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There are new, costeffective, easy to use, with simple cooms set up, relays available on the market, no problem
 
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