From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,FREEMAIL_FROM autolearn=ham autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,873e3ac877e7b6b6 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2003-08-17 04:49:48 PST Message-ID: <3F3F7342.29A8@mail.ru> Date: Sun, 17 Aug 2003 13:21:22 +0100 From: Dmytry Lavrov X-Mailer: Mozilla 3.0Gold (Win95; I) MIME-Version: 1.0 Newsgroups: comp.lang.ada Subject: Re: Nuclear Reactors & Blackout References: <3F3E3B4D.5893@mail.ru> Content-Type: text/plain; charset=koi8-r Content-Transfer-Encoding: 7bit NNTP-Posting-Host: 213.248.15.50 X-Trace: shknews01 1061111945 213.248.15.50 (17 Aug 2003 17:19:05 +0800) Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!newsfeed.berkeley.edu!ucberkeley!enews.sgi.com!nntp1.phx1.gblx.net!nntp.gblx.net!nntp.gblx.net!news2.ilink.net!shknews01 Xref: archiver1.google.com comp.lang.ada:41632 Date: 2003-08-17T13:21:22+01:00 List-Id: Ludovic Brenta wrote: > > According to the press here in Europe, it is perfectly possible that a > similar blackout, of similar magnitude, occur here. The cause is not > related to software (i.e. a blackout could occur even with 100% > perfect software). A blackout would be the result of a number of > factors. > > 1) Electricity cannot be stored (d'oh!) and therefore, there are > dispatchers that are on watch 24 hours a day to match supply and > demand. These dispatchers are usually country-wide. Their job is > to ensure that the production of power is exactly balanced by the > consumption, and that all electricity produced is properly carried > over the grid. > > 2) The high-voltage lines in the grid have limited capacity; they > overheat if too many ampers go through them (d'oh!). There are > "fuses" that protect these lines against overheating. > > 3) All power stations in Europe are interconnected; they are all on > the same high-voltage grid. This is done so that if one power > station fails for one reason or another, other power stations can > supply more power to make up for it. One third of Europe's power > is from nuclear plants, but that's irrelevant. > > Thus, if there is a big surge in demand for electricity, some lines in > the grid will shut themselves off in order not to melt down (I mean > the *lines*, not the *power plants*). The other lines in the grid > will then have to carry the extra power. They, in turn, run an > increased risk of exceeding their nominal capacity, and may also shut > themselves down. > > It would appear that the blackouts in the US were caused by such a > surge in demand (hint: air conditioning devices throughout the US > account for 30% of all electric power consumption). This was combined > with the fact that the demand in electric power has increased by 30% > in the last 10 years. And this was further combined with the fact > that very little investment has been made, over the last 10 years, to > increase either the supply capacity of power plants, or the bandwidth > of the grid. Basically, it's like a giant fuse went off because of > too much demand on the whole system. > > I've heard that one power plant went off-line, and that that started > the whole process of quickly overloading the lines from all other > power plants. Given the situation, I don't think that this is very > important. I think other blackouts could, indeed *will* happen, > whether or not a power plant goes offline in the future. It may very > well happen that one day there is just too much demand and too little > supply. This has happened before in California, albeit to a lesser > scale. > > -- > Ludovic Brenta. Heh,if net are overloaded,SUPPLIES are diconnected??? Why not disconnect some towns to save network (as in xUSSR "-)?? What's , USA network are so simple and based on plants connected in parallel ,works as one plant,and towns in parallel,works as one consumer? If so,it's simply idiotism. There is so simple to make non-buggy (by overloading) network: let's each supply provides energy for nearest towns(let's call it "sector"),and maximal power of towns = power of supply.When supply aren't 100% used,some energy are transmitted to other regions.If supply are overloaded by local towns,it's only consumes energy from another plants.There are buffers between sectors that newer overlod plants,only transmits as many energy as sector aren't uses. And if one sector are overloaded,when it's overloaded more than can get from another sectors,some non-critical pards of the sector are disconnected,and other sectors aren't overloaded. In Russia,there are as many short circuits a year,and we should have blackouts every week if network work same way as in USA. I don't sure that it's blackout caused only by overloading Another reason why USA shutdown may caused: Storing problems(load-not-in-phase problems): It's AC lines! And in AC line,if one connected a 1000W light bulb,power transmitted in cables are 1000VA. If one connected 1000W motor,or transformer/computer/etc,power in cables may be far highter than 1000VA. For example,if i will connect capacitor to the wall plug,power consumed=0;and power of generator/substation needed<>0,and current in cable<>0.I can blow fuses without consumtion of energy. Main problem that energy ARE stored,but for short time. Synchronisation/phase problems: And how AC lines are synchronised? If they are 100% in phase,there is no current in lines(cable have inductance!). So,to transmit energy,they should be not-in-phase. But if they are TOO not in phase,there are BIG overloading of lines. Another synchronisation problem: many PulsedPowerSupply are used(ex. in your computer).There are standard for freqency of osscilator in PPS.And,if they all will be synchorinised,it's will be VERY bad.(i don't sure if it's possible). All these problems may cause global blackout with "help" from software bugs. I have read book about it,but i fogot how to write author's name..Haily,Heily,,sorry for my poor english, accordinly to this book,it's caused by heroic idiotic managers(good guys in this book) that are overloading plants and lowering voltage in network until AUTOMATIC SAFETY system stop these idiots! Dmytry Lavrov.