Advanced relaying for HVDC lines

Abstract

To fulfill the growing electricity demand, installing new power plants and harnessing renewable energy from alternate sources are the only probable solutions. However, these sources are located at different locations from the load centre. Thus, supplying newlineuninterrupted and reliable electricity cannot be achieved without installing efficient bulk-capacity transmission line (TL) infrastructure. The existing transmission technology based on extra high voltage alternating current (EHV-AC) has drawbacks of increased cost, huge reactive compensation, stability issues, etc., when used beyond critical length. Hence, an alternate transmission technology based on high voltage direct current (HVDC) is preferred if electricity transmission exceeds vital lengths. HVDC technology uses power electronics (PE) based current or voltage source converters to newlineconvert alternating current (AC) supply into direct current (DC) for large-distance transmission carrying bulk power. At the receiving or load terminal of the TLs, DC is again transformed back into AC for distribution purposes.