The Use of Series Capacitors to Obtain Maximum EHV Transmission Capability

Series compensation can substantially increase the transmission capability of EHV (extra-high-voltage) systems, permitting a higher loading per right of way. Several of the possible circuit arrangements that can be used for insertion of series capacitors into a transmission system are cited in this paper. Certain technical problems of using series capacitors are analyzed. The effects of fault switching time on stability limit for series-compensated circuits and of delaying reinsertion of series capacitors after fault clearing are indicated for particular configurations. The relative economics of various degrees of series compensation and number of intermediate switching stations for 500 kv and distances up to 400 miles are also shown.