Why in LARGEST POWER STATION per phase individual transformers are used instead of one big transformer???

 ⇨I visited in ADANI THERMAL POWER STATION Mundra Gujarat. The capacity of the power station is approximately 4650MW in this power station I seen that in per phase one individual transformer are kept Instead of One Big three phase transformer.

⇨It is because for such big power station if we used one transformer then it becomes too much large approximately some MW to Few GW rating of transformer are required.

⇨If we assume to use such big transformer then it becomes too difficult to handle it and also the weights of core and winding, volume of oil in the tank, Auxiliary equipments like breather, Colling system, conservator tank, Buchholz relay etc. The Summation of weight of all this accessory are in TONNES so it is too much difficulty in transportation.

⇨Also suppose any major fault is occurs in such big transformer then first it is isolate and it's all the parts are overhauling and then faulty parts are repair after this repairing agin all parts are assemble during this entire period all the consumers are Deprived of Electricity it is big disadvantage of Use of one Big transformer.

Fig(a) Approximate Specifications of Power transformer

⇨Please observed in above table, in this table technical specifications of some MW power transformer are given from it we know that the total weight of transformer is in TONNE specially for above specifications the total weight is 233.2 tonne (1 tonne =1000 kg).  so it not easy to transport it from Manufacturers to power station site.

➝ To avoid this all above difficulty in transportation and handling of power transformer and to increases the reliability of the power system it is preferable to use PER PHASE INDIVIDUAL TRANSFORMER INSTEAD OF ONE BIG TRANSFORMER.

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