24 September, 2020

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Blackout Report Simplified

By Kumar David

Prof. Kumar David

The public is king so it is necessary in matters of importance to put across issues in a way that most people can understand. I will simplify the Interim Report of the Committee investigating the 17 August, 2020 blackout and add my own comments as a guide discourse. Let’s see if I can manage to keep it both intelligible to the layman and technically acceptable.

Point 1: The maintenance crew at Kerawalapitiya switched on a 220kV circuit breaker energising a bus-bar that was earthed for maintenance. (Bus-bars are three long tubes (3-phase), which serve as junctions to connect together numerous items such as generators, transformers and transmission lines). The crew did not follow correct procedures and the interlock which should have prevented the error did no function or was wrongfully bypassed. The Committee, rightly, reprimands the CEB, which I guess is already, on an all Island basis, updating manuals, retraining crew and checking interlocks. This much is now common knowledge.

Point 2: Protection systems are coordinated. Circuit-breakers must trip around a faulted zone isolating only a small portion to “quarantine the disease” (rush of current, collapse of voltage). In the case of a crucial element like a 220kV grid station this should have been completed within four AC cycles (80ms) but took eight cycles (160ms). Enough time for all hell to break loose – generators were disconnected by their protection systems, transmission lines switched out and loads (chaps like you and I) kicked out, all in an attempt to save the system – that is keep some of it up and running. This is automatic; the poor buggers in the Control Centre can do no more than wet their pants and break into a cold-sweat in the 0.5 or so seconds in which all this happened. However, the big question is why did the coordination of system protection fail? Over to you CEB.

Point 3: When transmission circuits trip and loads a rejected there is too much generation on-line and not enough connected load. Its rather like a car engine running at full power and not enough traction load on the wheels. The car accelerates. In electrical systems if the input power is too much, system frequency goes up as generators speed up! Protection at Norochcholi promptly did its job to save its own generators. The rate at which speed was rising was too high so it cut back its generators and finally tripped out the station. Oh dear, the opposite effect followed (not enough generation) so frequency started falling!  This prompted ‘under frequency load-shedding’ to disconnect loads making other “load-less” generators trip. The system died in minutes

Now we come to two points, the first irritating, the second new and unfamiliar. 

Point 4: If Norochcholi trips out suddenly it takes a heck of a long time (days) to bring it up to full power again. There is a part of the boiler known as the drum which has to cool down and that takes days. What is irritating is that this has been known for 12 years and the CEB has been told ever so often to fit auxiliary systems to help expedite restart. Not much seems to have been done. That’s why we had rotating power-cuts for four days as generators elsewhere tried to cope with the absence of Big Fellow, the 900MW Norochcholi plant.

Point 5: This is the really odd one. The Committee seems baffled; the report is replete with “could be”, “maybe”, “can be attributed to” and “internal fault of the generator” (I don’t buy this last one). Nevertheless, I don’t fault it because neither the Committee nor CEB engineers who must have been advising it have got to the bottom of the jinx. The problem was repetitive and goes like this. Controllers started Victoria and connected to Biyagama. When they attempted to restore supply from there to load-centres the generators tripped. This happened three times. In desperation they tried again using Kothmale and three times again failed though this time the system held-on, on ‘life-support’ as it were, for up to 10 minutes. On the seventh attempt, again using Kotmale and after disconnecting some automatic controls, the system survived, but not without a minute or two of jack-in-the-box frequency oscillations between 48Hz and 54Hz; huge. Unlike the impact of the initial short-circuit which is in the millisecond time domain, these reconnection difficulties are in the slower many-second domain – stability, control-damping, load-mismatch and such electro-mechanical glitches. A very different ball-game.

Ok that’s the story in simple words. What needs to be done? Maintenance crews have to be better trained and manuals and procedures improved; interlocking mechanisms rechecked, protection coordination revisited, and the bloody mess regarding Norochcholi restarting has to be fixed. Intellectually, the challenge is to accomplish credible in-depth analyses of the start-shut drama on reenergisation from black.   

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Latest comments

  • 16
    1

    My home and mobile phone numbers were blocked by the local office of the CEB to stop me from complaining about the incessant interruption of electricity which was annoying very much as it adversely affected our daily activity. The general attitude of the locals was to take it as life as usual. I made a record of date, time and duration of power interruptions and it was mailed to Mr. Chanpika Ranawaka who was the Minister in charge of CEB pointing out that the CEB Engineers for sure are ignorant of the need for the CEB to exist. After many months I received a response that my correspondence has been forwarded to a minion in the CEB for action: end of the story. By right the entire staff of the CEB must be rounded up and drown them in the Indian Ocean. The entire set up is so corrupt that it is beyond redemption. They behave like vultures around a rotting carcass.

    • 1
      0

      This comment was removed by a moderator because it didn’t abide by our Comment policy.

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    • 1
      0

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    • 1
      0

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      • 2
        1

        Wow! Three in a row LM. And yet that foul mouthed illiterate Johnpillai is allowed to spout his racist filth just below you. It makes one wonder who CT’s rules apply to and why.

  • 13
    5

    Living far away from the sad sorry shitty rajapuka s island I am told that the poor starving people have still got to for no fault of theirs have to undergo more continuous power cuts.
    &
    If the big talking rajapukas cannot do a simple task how on earth can they turn this beggars colony into one of prosperity.?
    &
    It’s all only farts and no droppings of ?.
    The foolish racist donkeys who wasted their hold sacred ballots to vote these money grabbing big time crooks will suffer till they drop death due to starvation.
    &
    Don’t they deserve to conk off whilst the rajapukas build up their hora boru Salli with the sole intention of becoming the world most richest multi facetted family.
    &
    Most sinhalaya are modayas kavun kannda yohadayo.

  • 4
    0

    Thanks.
    That is neat and tells us what should be done.
    I hope that the CEB takes note.
    *
    People waiting to abuse their pet targets are not interested in anything else.

  • 4
    0

    The Sacrifice (Part-1): Thanks, Guru, for putting it in such simple words. I would like to suggest that CEB creates a new position for a DGM (Occult Matters). I am not joking here, and the suggestion is based on the experience I had in Bahrain as an Electrical Engineer.

    Here is what happened. In Bahrain it is usual to take all machines one by one, for inspection, during the winter months when the load is low. One such machine was being commissioned after inspection when we had trouble in starting it. It was simply refusing to start.

    On checking and rechecking the whole system a dozen times, nothing wrong could be found. We were running out of all options and the Manager was going cazy. The site engineer of ABB was called in, as were so many other Pandithayas.

  • 5
    0

    The Sacrifice (Part 2): Finally, when all hope faded away, one of the Indian Engineers made an out of the box suggestion that we make a live sacrifice in the form of a chicken.

    The pressure was so bad that the Manager would have agreed even to make a human sacrifice. A vehicle was dispatched with sufficient petty cash to buy a fully grown cock. The driver and the Indian Engineer came back with a beautifully colored cock. It was then placed on the main Gas Turbine and the neck cut with one blow from a sharp knife.

    Leaving the cock to do its death dance, everyone ran in to the Control Room and the Manager himself pressed the Start button. Lo and Behold! The machine ran up smoothly under the control of its Start Up program and went on load.

    So you see, there are things in the world that we do not understand and make life complicated. At such times we need top guy in charge to take over.

  • 8
    0

    Mr. Edvin Rodrigo. Great. Fantastic idea. Chop of the head of the Chairman. And let there be light.

  • 1
    3

    “Ok that’s the story in simple words. “ Does that end sounds like CEB remitted in full all the outstanding to Prof. K? At least I think so! I still like to know who is the black-sheep in the CEB? Did he go to parliament (Sorry, I meant junior high school)?

    Now……..what is next?

    Let us go to Kandy and simplify the story of Kandy Ayatollah’s computers’ transmission circuits tripping.

    Wait a sec,

    what is that shaking?

    Is that somebody targeting Dalada Maligawe where the Ayatollahs stays? Can Prof. K write a simplified story of why Kandy is shaking these days? Is that because planet GURU(Viyazha Maaram) moving from North to South and staring to give his troubles in South?

  • 1
    0

    Professor,
    People in the senior management like gm and ffm are people not the best.
    What we have got is mediocre because best were not recruited because they were Tamils or they have migrated because people were not recruited on their talent but who knew them.
    I knew one of your best sould not enter because he was a Tamil but his mediocre batchmate became GM

    • 2
      0

      D
      One thing that I can say is that Tamils generally preferred Civil Engineering to Electrical & Mechanical Engineering for long.
      As a result with a few exceptions, not many good Tamil electrical engineering graduates were to be found until recent decades.
      In my batch with 50% Tamils none opted for EE. In Prof. David’s batch he was the exceptional Tamil, who grew up in Colombo.
      In the batch after mine, there was a single Tamil EE student, very bright like Prof. David, but he was an Indian immigrant.
      So the story goes. The pattern persisted for several decades.
      So let us be cautious about negative claims re quality of recruitment.

      • 1
        0

        SJ,
        Thanks.
        I had serious concerns about selecting Electrical Engineering because it was considered very difficult to complete the degree within four years, let alone graduating with a class.
        There were some lecturers even suggesting that Electrical Engineering is not for people of moderate intelligence and there were other options (an indirect reference to Mechanical and Civil Engineering).
        During our time, everybody was scared to select Electrical Engineering, but that was certainly not based on ethnicity.

        • 0
          0

          SA
          Thanks
          Really, not many took more than 4 years to complete the EE degree. But I know two who took incredibly long. Such instances have an influence on student opinion.
          Again I know people who did the same in the other disciplines.
          *
          With Civil Engineering, the subjects were less mathematical than the others (especially EE) at one time. Now it is a different board game with Structural analysis, Finite Element Method etc.
          *
          I will accept your version of things, if the brighter Tamil students too did not run away from EE.
          They kept away from Mech Eng too noticeably.
          The exceptions did exceptionally well in EE and Mech Eng.

      • 2
        0

        I think you guys were from Moratuwa ? In the later years, there were no longer 50% Tamil batches . and many Tamil engineers took to EE. I think there was still a lot who went to CE due to dowries being higher for them. I wouldn’t ever look down on the quality of engineers in the CEB . In fact if anything in my career I have almost always found Engineers from Sri Lanka of the highest quality compared to most other countries. Due to the quality of the teachers we had. and the average quality of the university intake.

        • 1
          0

          a14455
          “I think you guys were from Moratuwa?”
          *
          Pretty good first guess.
          Try again, you cannot go wrong— unless you say Ruhuna, Jaffna, South Eastern or Open University (or now Sri Jayawarenapura as well)
          *
          BTW
          The last 50% batch entered in 1960.

          • 1
            0

            Dear SJ,

            You had added somewhere, that many dont have the practical knowledge in technology – this is exactly the problem with science and medical graduates if they were graduated from a developing country. This is why I repeated that Uni dons should have permanent link programs with industries of each country of their origin. I came to know several PG students from SL, Bangaladesh, Nepal and India. All of them were well at theory, but they had not the least knowledge about finding solutions on even thrivial issues ; their knowledge in school physics restrict to their theoretical exams.
            I dont think so long a bunch of thugs would be the leaders to the country,long due educational reforms would be made meeting with the expectations, in the years to come. That is why I believe, it is essential Uni academic staffs to closely work with ministry of higher education in a country.

            • 0
              0

              LM
              No university provides technical training, except by way of industrial experience for up to 6 months in engineering. Medical students do their internship.
              One learns much on the job. The theory and other fundamentals learned in the university are essential for that learning.
              Very rarely has any of our graduated fared badly in his/her chosen career.
              Do you think that fresh American, British or Australian graduates are any better?
              India has a sub-system of ‘private colleges’ that produces sub-standard graduates. The good universities are on par with anything good elsewhere.
              *
              ” I dont think so long a bunch of thugs would be the leaders…”
              What makes them thugs?
              It is most unfair to abuse young people as thugs etc. without basis.

  • 2
    0

    Great explanation prof .

  • 0
    0

    Prof Kum has describes many facts which are not in the public domain and did not crop up in so called TV interviews with expert panellists conducted in several stations. Some points are interesting and wonder why no attention was made.
    Prof. Kum, with all his knowledge in technicalities and having delved into the matter should express opinion on a few things which the general public would be interested in:

    (1) Are we to surmise that the CEB personnel knew certain systemic weaknesses as elaborated by you in your points from the very beginning enabling any mischief maker, if any, to make full use of it to create pandemonium in the country?

    (2) Do circumstances indicate that the crisis was a created one to serve an agenda? This question is raised simply because of pronouncements made by so called other experts to the effect that provision of renewable energy does not go hand in hand with coal power and that if the state policy of promoting renewable energy can be best supplemented fossil fuel related supplies.

    If the action can be proved deliberate the culprits must be charged say for treason to attract heavy penalties.

    • 0
      0

      Two specific questions have been put to me. The answers are a conditional NO to the first question. Of course the CEB top knew about he Norochcholi restarting delay problem and should have been aware of weaknesses in protection coordination. But things were not left like that to encourage “mischief makers”
      My answer to the second question – sabotage – is an unconditional NO.

  • 4
    1

    I think the minister for electricity (ie Minister of CEB) Dallas promised quite openly on national TV that he would resign if the fault was the CEB’s. It certainly looks from this article like it was a fault or even a series of faults of the CEB but has the minister resigned?

    • 1
      0

      Lasantha,

      But the minister has not yet resigned.

      Does this mean that the fault does not lie with CEB as expected ? or why are they silent now ?
      .
      See, regarding KURUNAGALA, they burried it under the carpet with the election victory to that Jonsten, who was the man behind that demolition of RAJYA SABA BUILDING.
      :
      Yet today, not a single pledge is fulfilled going by president election promises

      I think the situation is like PIGs might fly, if current men would achieve an inch of progress for the benefit of the masses.

  • 0
    0

    Las Peth.
    He is not the only Minister but one in a long line for years past who have said they will resign if…. but when the “if” actually happened, various excuses are trotted out. Actually in this case Dullas said if the fault is in the Ministry etc. So he will save face saying CEB is not a baby of the Ministry.

  • 1
    0

    Everything in Sri Lanka breaks down. There are a few good technicians and engineers in the lower ranks of the CEB no doubt. But they are fast depleting. The grid should be a fail-safe system but it is not. The same is true of the railways. The national transport board and its fleet of lorry body buses whose drivers need a medal for keep the thing on the road, The telecom also suffered this way until it was privatized. Not sure if there has been any improvement since then. In the private sector the cost of maintaining anything mechanical or electrical is astronomical because is always breaks down for no valid reason. Ditto for Cars. Sri lanakans will only trust Toyota nothing else can stand the abuse and keep running they have figured this out. I once bought a Hyundai and everyone laughed at me. What a silly old place this is.

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