Converter Transformer For HVDC Systems

For short distance transmission of power, AC transmissions are widely prefered. For long distance transmission of power, HVDC transmissions are more economical than AC. As all generating stations are generating power in ac, we are in need to convert this AC to HVDC. For this conversion, converter transformer is get used. Converter transformer is the combination of converter and transformer.

Construction of Converter Transformer

Converter transformersfor 12 pulse rectification have three windings, one star connected AC winding and two valve windings-one connected in delta and the other in star. The AC winding is connected to AC system, whereas the valve windings are connected to convertors which, in turn, are connected in series to build up the required level of DC voltage.

Note:

HVDC transformers are either built as single-phase or three phase units as per our requirement. Insultion provided for Converter transformer is very high as it needs to withstand voltage stress under both AC and DC condition.