Cascade Effect and Grid Failure -

With regard to utilities infrastructures, how does a Cascade Effect relate to a Grid Failure? By "Cascade Effect," I mean failures of interconnected systems that have become imcompatible due to their having been "y2k fixed" in different ways.

IEEE has expressed at least moderate concerns about cascade effect:

Year 2000 Technical Information Statement - July 30, 1999 http://www.ieee.org/organizations/tab/Y2kFocus_tisrel11.PDF

Technical Realities Of The Y2K Act - June 18, 1999 http://ieee.com/organizations/tab/Y2kFocus_liabmem1.PDF

I am not sure that this is even considered by NERC in rating companies as 'R' or 'RE.' Anyone have any thoughts or input as to whether such cascading failures could leapfrog beyond local problems? I assume that any failures of this type would be extremely difficult to correct, since they would require extensive reprogramming?

I'm just a clerk, don't know a 010 from a 101, but would appreciate any comments. -Jim Young jyoung@famvid.com

-- Anonymous, November 03, 1999

Answers

Jim,

In the electricty industry a Cascade fault has a totally different meaning to what you appear to be proposing.

A cascade is caused by the failure of interconnected systems, but that does not meany computer or embedded systems, but rather it refers to power lines generators etc.

An example of a cascade failure could be something like:

An earth fault occurs close to a circuit breaker, but in a blind spot for protection. Therefore that breaker doesn't trip and the fault has to clear remotely. In the process generation close to the fault is lost, and remaining lines become overloaded. The overloaded lines trip and cuase islanding in one area with an excess of generation, and low frequency due to a lack of generation in another area. The high frequency area loses its generation on overspeed, and the low frequency area struggles on with high overloads as the generating plant tries to catch up. More lines trip, and the resulting instability causes extremely low voltages in other areas with resulting load shedding. Eventaully the grid settles down having blacked out one area, and intermittent failures or brownouts elsewhere.

This is what a cascade fault is like. But no link to Y2K.

I did glance through your links but I did not see anything that suggested any incompatibility could cause failures. Could you reproduce the relevent section, or enlarge on what you mean?

Malcolm.

-- Anonymous, November 04, 1999

Jim:

Malcom explained one type of "cascading" event. In general, various types of "cascading" events have been happening for years. They can occur as a result of large amounts of generation tripping in a region, protective relay schemes mis-operating, inoperative breakers, etc.

In regards to your specific question of interconnection relays being "fixed" in a different manner at each end, I would find very improbable. Technicians at each company coordinates an outage of the protection equipement and very carefully coordinate their changes. They have to by the very nature of such sophisticated equipment. Doesn't mean such sophisticated equipement might not mal-function but... (the "chances" of mal-functioning might be increased because the CHANCES of many things going wrong will increase)

Another point I would make for the layman. IF (emphasis) 25%, or near one out of four, generators tripped in a given region, or across the U.S. at the same time, you would have many regions in the black across the country. This event would FIND those protective devices ready to fail and those planned isolation tripping schemes that would mis-operate. I'm not sure this could be called a grid failure as it wasn't designed (nor would anyone want to pay for it) to handle such an event. Thousands & thousands of points to "go wrong" and many would.

You might want to read my answer in "A misleading statement" in this forum also.

Quenton

-- Anonymous, November 04, 1999

Malcom and Quentin,

Thank you both for responding to my question. The relevant sections, to which I was referring, are reproduced below:

Excerpt Below From: Year 2000 Technical Information Statement - July 30, 1999 http://www.ieee.org/organizations/tab/Y2kFocus_tisrel11.PDF

"There *will be* failures of computer-based systems, especially those rich with complex software and interconnections to other systems; even if all such systems could be made to be "Y2K compliant" (itself a highly improbably occurrence), they will not necessarily all be compliant in the same way and so will lose some of their effective connectivity. This is especially true across organizational boundaries, where remediation control and responsibility are ambiguous. These interconnection failures will be just as dangerous as individual system failures, if not more so, as they have a better chance of cascading to yet other systems. The question is whether those system failures affect the organization they support in any meaningful way that, over time, either degrades its internal operations and health or, very importantly, becomes "visible" by degrading the availability or quality of the goods or services it normally delivers to the outside world that those organizations depend upon to maintain their operations. The answer for each organization will depend upon both the farsighted and in-the-moment development and deployment of adaptive contingency strategies, tactical plans and processes."

Excerpt Below From: Technical Realities Of The Y2K Act - June 18, 1999 http://ieee.com/organizations/tab/Y2kFocus_liabmem1.PDF

"1. - 1.1 'Y2K Compliant' Does Not Equal 'No Y2K Failures.' If an organization makes all of its systems 'Y2K compliant', it does not mean that this same organization will not experience Y2K failures causing harm to itself and other organizations. In fact, efforts to become 'Y2K complaint' in one place could be the direct cause of such failures in others. If interconnected systems are made compliant in different ways, they will be incompatible with each other. Many systems in government and industry are mistakenly being treated as if they were independent and fixed in the most expedient way for each of them. When this 'Humpty Dumpty' is put back together again, it will not work as expected without complete testing, which is unlikely (see Complexity Kills below)."

I (Jim Young here again) do not believe there will be any typos in the final version I post and send by email to both of you...but, if there are any errors, they are mine.

Again, I am only a layperson with no expertise in software at all. However (and I am honestly not trying to flame anyone here), we have all experienced being told, "Don't worry. We are very careful in our business. We know what we are doing. Our business is different from the others." Then, at the worst possible moment, Murphy's Law goes into overdrive...and the car dies, or the structure collapses, or we discover we are taking the wrong medications, or the new computer system does not function as expected, or...

As a layperson, I realize that I'm asking for technical information that laypeople can understand and use. And I do understand that the utilities industry is necessarily protected by a large number of checks and failsafes. But, is the IEEE, the pinnacle and gold standard, all wet here? In this dead heat rush toward compliance, are the utilities somehow immune from "cascading failures" as described by the IEEE? Or do I just not, as a layperson, understand well enough that this prestigious institution meant something other than what it sounds like they meant?

Best regards, Jim Young jyoung@famvid.com

-- Anonymous, November 04, 1999

Quenton, I'm sorry for mis-spelling your name in my previous post. Won't happen again. -Jim Y.

-- Anonymous, November 04, 1999

Jim & All:

Actually, I guess I kind of failed in getting my point across. I was trying to paint a picture of the following observations/comments, IMHO, based on my 28 years of electric utility operations experience:

1) The PROBABILITY of major outages and events will increase as a result of the Y2K computer, imbedded chips, free market systems, and the LAWS of PHYSICS.

2) Major regions of the U.S., if not entirely, CAN go in the lack WITHOUT ANY transmission lines relaying falsely...although should just 25% of on-line generation trip, many transmission lines would probably trip for various reasons.

3) The new "open-marketplace" of electrical supply will add to this probablility...and any resolution of problems.

4) A recent suggestion by an expert to operate all companies as islands would help some regions....adversely impact others. The same thing could be accomplished, actually be better, for companies to stay interconnected, but reduce intertie schedules between each other and between regions for a week or so surrounding the transition. This would minimize electrical impact but enhance aid to each other. Islanding won't happen anyway...litigation, injunctions, etc., would stop it.

5) I advised in one posting that should major systems black out, that restorations can take from 24 hours to days. I want to emphasize that such time frames are OPTIMUM. IF Y2K glitches are what shuts everything down, restoration will be much longer...think about it. Imagine trying to find THAT component that tripped THAT piece of equipment...would those plant controls be capable of restart, etc. Would involved relay protection BE ABLE to be utilized for return?

6) Having said all that, I DON'T believe there will by anything bus some outages here & there....maybe.

7) I would be more concerned about the fuel supply in the days and weeks after the rollover as a result of Y2K....not midnight on 12/31.

8) Another point. IF major industries start taking all of their load of at the end of December, they will also INCREASE the probablility of further problems or blackouts occuring as less generation could actually be kept on line and other problems associated with minimum load periods.

Quenton Hendricks

-- Anonymous, November 05, 1999

Quenton,

Thank you sincerely.

That is about as honest (and 'lay oriented') as it gets, I'd say. I appreciate your candor. Trying to prepare for this thing, in a reasonable non-hysteric manner, has become the most difficult, most stressful, most uncertain project I've ever taken on. I hope for the least amount of trouble for all of us, of course. And yet, I am always haunted by a sense that I may be wasting much of our savings, the strictly y2k expenditures that cannot be eaten or otherwise consumed.

But, I believe in being a survivor. I have a wife and three cats in this apartment to care for. And, under all of my doubt, I know that I've made the best judgment call I can, given what we know, or don't know, at this point.

Forgive me if my last post ended with a faint sarcasm. No harm intended to anyone other than y2k. Thank you for your clarity and honesty.

Respects, Jim Y.

-- Anonymous, November 05, 1999