Transformers Continue to Fail

(Irfan Akhtar, Lahore)

Guddu Failed Transformer 450 MVA (Jan 21, 2016)

A 450 MVA Auto Transformer failed in NTDC network at Guddu was a news I was reading on social media website today. It reminded of an event that occurred 9 years ago. I was wondering if NTDC has implemented CBMs techniques for its assets in the network, if they have been able to create Asset Health Indices (AHI), if they are doing RLAs (residual life assessment), If they are able to perform forensic analysis now. I am gatheting details on this failure as of now and will share my finding with you in due course of time.

It was 2006 perhaps. I don’t remember the month exactly. Reading the newspaper which was still a norm during those times, I came across a news related to power. Two transformers burnt in Kala Shah Kaku in NTDC system. I was working as Manager E&I at Saba Power Plant, a subsidiary of Elpaso USA. We had one of the finest CBM and RCM strategies in place for Asset Management. Our knowledge in Transformer was very up to date being guided by Elpaso head office based on best practices being followed in US.

I wondered for a moment why a utility company could not prevent an inservice failure. Getting one transformer burnt could have been categorized as a one off event but two in one substation was not normal at all. Something was wrong. I was aware that NTDC/Wapda found it hard to shutdown the transformers for any diagnostics. But for a 220 KV transformer, these kind of failures must be investigated.

I called Mansoor Awan, a classfellow from MSc Electrical Engineering from UET Lahore. He was working as Assistant Manager in System Protections. System protections is considered as the brain for NTDC. Whatever catastrophe strikes in Wapda, system protection people are involved. One reason could be that there are people who think that protection systems can avoid a fault. They forget that protections operate on fault occurrence to mitigate the consequences like an Air Bag in your car. Well, I asked him for details of transformer failures. To my astonishment, they have had many failures in recent years leading upto this event where two transformers blew up in one place. He told me that NTDC Chief has constituted a committee to investigate the issue and report for actions needed to avoid that kind of failures in future. Committee had Chief Engineer system protection, Chief Engineer design and Mirza Akram – Wapda expert on transformers. Mansoor encouraged me to go and meet GM GSO NTDC. Remember I was still working with Saba Power Plant.

In national interest, I decided to go ahead and seek an appointment with GM GSO. I went there on Saturday morning which was an off day for us. I managed to enter wapda-house main building with the assistance of Mansoor Awan who arranged the gate pass. He showed me the office of the GM. Standing in front of his office, I was on my own. No visiting card, No reference. I was Mr. Nobody trying to meet a Grade 20 officer in Pakistan. I thought I was crazy. There was a temptation to go back and have rest on an off day from power plant.

I somehow managed to move in with some courage reciting Holy Phrases seeking divine intervention. There was a personal secretary sitting there managing files and talking to probably a tea boy. I realized that there was another door where the technocrat would be sitting. I asked the secretary to take me to GM GSO. He looked at me and asked which company I was coming from. “I am an electrical engineer and wish to share my experiences on Transformers with regards to KSK failures, if GM could meet me”, I was pleading. He asked me to wait there. I sat for about 1 hour when someone came out. The secretary picked up the extension and talked to the GM and told him about me. He allowed me to go in. I had couple of technical papers from Doble that Brian had shared with me when Doble came for RLA at Saba power plant last year and some details about CBM for transformers.

GM was sitting behind a large table with Pakistani flag on his left side and three gentlemen sitting in from of him. “why are you here and what do you know about our transformers”, GM said. I introduced myself as Manager E&I from Saba Power Plant and reading about the incident in newspaper. He was furious. I handed him the technical stuff that I had. He looked at it and then threw those papers on the floor with arrogance. “we are busy in investigating the failure and you want me to look at this crap. We know everything. We are experts”. GM angrily was showing me the door. I requested if he could listen to me for five minutes with my eyes already getting wet with humiliation and tears.

He glanced at other three people and looked at his wrist watch. “ok your five minutes start now”. I took a sigh of relief, gathered some courage and started talking about the CBMs that are needed to assess the condition of a transformer, international experiences and best practices. I even told him about ABB recommendation to NTDC 2 years ago about using SFRA in their condition assessment plan (mansoor had told me about it). He stopped me after exactly five minutes by raising his hand dismissing me from my presence. I was speechless and didn’t know what would be coming next. He picked up the phone. I was sure he was calling the security to throw me out and ban my entry in wapda house. He told his secretary: “Invite all engineers, Chief engineers from GSO, GSC and Design on coming Thursday by writing a letter on behalf of Chief Executive NTDC which he would get signed. Young man (Irfan Akhtar) will be giving a lecture on Transformer Condition Assessment”. I was overwhelmed. He introduced me to the investigation committee members and asked them to get my help also. Later he included my name in the reactor failure investigation committee as well.

When I entered the seminar hall on Thursday, there were about 50 engineers all very senior to me in the age range of 40-60 I would guess.There was CE HO GSO, CE NTDC Circles, CE Design, CE Planning, GM GSO, GM GSC, CE GSC and many others. I started the presentation I had prepared in last 2 days working really hard. CEO NTDC was also there. When I finished, there was a silence for a moment. Then CEO started clapping and every one followed. I cannot put that feeling in words. I had perhaps conquered the Mount Everest. Oh yes!. ”We need people like you to keep coming to us with these kind of knowledge sharing presentations”, someone said. In the presentation, I introduced to them SFRA which was new at that time and it was definitely before IEC 60076-18 was introduced or IEEE C57.149. I talked about DGA, Oil quality testing and some online techniques including RFI/TEV PD testing”.

The General Manager who initially brought tears to my eyes after throwing the papers on floor and humiliating me, later on helped me a lot esp when it came to dealing with NTDC. In 2007, we held our first seminar with Doble USA in Lahore. Qazi Naeem was the chief guest. He was sick on that day but came on my request. The seminar “ managing asset performances” did not have any product presentations or marketing gimmicks. It was a huge success. Prescon was instantly on the horizon along with Doble.

Changing the mindset in government utilities in a country like Pakistan is difficult thing but persistence pays off. Now with ever improving K Electric, NTDC/WAPDA/PEPCO/GENCOs/DISCOs have a benchmark and a little bit of competition. They have to introduce the concepts of RCM, Asset Management / ISO 55000 in their system. We already have suffered 04 major breakdowns across country in last one month or so affecting more than 50% of the area atleast. The other day when I was giving training on Transient Stability at K Electric, Azm Training Center, I realized that Wapda and its associated companies could also take example of private companies. I don’t want to go into debate of privatizing Wapda. But bringing in the culture of change is what Wapda badly needs now. Culture of innovation, R&D and accountability has to be set in. Pakistanis deserve reliable power supply at the very least. Otherwise, the transformer will keep in failing, we will keep on facing cascaded trippings. I must share with you guys that after 1965 blackout, US President Johnson called a meeting of Energy & utility Managers. They formed Reliability Councils like FERC, NERC which served as a catalyst of change for the rest of the world. Where are we? Where is our FERC/NERC?

Author is an a consultant in Power Generation, Transmission and Distribution holding a BSc Electrical Engineering and MSc Electrical Engineering degree and nearly 20 years of experience.
 

Irfan Akhtar
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