Hello. We are working in 1 MW PV plant using 360/33 kV transfomers.
The question is: In photovoltaic plants sometimes it is necessary to connect the (-pole) to hearth in the input of inverter. So, the primary winding of transformer has AC (360VAC) and also DC voltage (350VDC average). It can produce a DC-stress in the transformer? Is there necessary any special transformer design? What do you recommend? I have only found in your web something about DC and transformers.
If there is a DC (direct current) being inputted into the transformer, then it needs to be quantified as it can have a significant effect on the transformer.
Depending on the transformer core induction level, even a small component DC < 1% of the rated current, could cause the transformer core to saturate, leading to higher noise levels, losses and overheating of the transformer.
You should contact with your local ABB representative who can put you in contact with the technical representative in the appropriate factory. Pls follow the link to find your ABB local contact: http://www.abb.com/transformers
If you want to purchase a product, need any pricing information or need help or support from ABB, please contact your local partner.