Ohmic losses - influence of MV Transformers on MV Wires losses

[Gilles]

Hi,

In the detailed losses ohmic tab, changing the number of MV transformers has effect on STC losses. The length of MV cables also has an influence on the ohmic losses.

I understand why the length has an influence; losses are directly proportional to cable length. But why would adding MV transformers change this? Why the number of transformers in a given site has anything to do with the cable ohmic losses between the PV field and the delivery substation?

Below three printscreens that illustrate the change I'd like to better understand. Thank you for your support.

 

 

[Linda Thoren]

Hello,

Adding transformers results in a reduced current load for each individual transformer. The Loss fraction at STC thus decrease at each transformer, but to evaluate the entire system you have to run a simulation and look at the loss diagram.