I'm an intern at an aluminium smelter and am part of the power plant there. They replaced the 33 kV transformers with the 132 kV ones because of an increase in the demand from the smelter. But what are the advantages of such a replacement, besides the obvious decrease in heat loss?
The new transformer is connected to the transmission grid at higher voltage level (132 kV) vs the old one (33 kV). This implies the increase in power rating (MVA). The old voltage level 33kV was too low for supplying the increased power demand. In addition, by removing the 33 kV voltage level, one step in the transmission chain has been removed. I am assuming that, in the old configuration, in addition to 11/33 kV transformation there was a 33/132 kV voltage transformer(s) somewhere between the smelter substation and the high voltage transmission grid. Three main benefits are: higher capacity, lower losses and minimization of number of voltage levels in the substation reduced costs of operation and maintenance.
I think you have terminology problems. 132 kV versus 33 kV is a voltage 4 time higher. So an application that used 33 kV would be severely overloaded at 132 kV. I suspect you mean 132 kVA vs 33 kVA? That is totally different. And represents the power level of the transformer by a factor of 4. Why do you think there would be less heat loss? .
