Title :
Design and operation of EHV transmission lines including long insulated cable and overhead sections
Author :
Colla, L. ; Gatta, F.M. ; Iliceto, F. ; Lauria, S.
Author_Institution :
Dept. of Electr. Eng., La Sapienza Univ., Rome
fDate :
Nov. 29 2005-Dec. 2 2005
Abstract :
Application of EHV lines formed by series connected overhead sections and XLPE-insulated cables sections is planned in various projects in Europe. At first the maximum feasible length of 380 kV-50 Hz and of 500 kV-60 Hz XLPE cable lines is calculated as a function of the power carrying capacity derating due to charging current. Then shunt compensation and optimal voltage-reactive power control are analysed with use of shunt reactors with tapped windings and on-load tap changer for regulation of Mvar output. The authors ATP-EMTP electromagnetic transient analysis of the long mixed EHV lines has revealed the risk of sustained overvoltages due to resonance on 3rd harmonics. The phenomenon is described and countermeasures are proposed. The feasibility of the single-pole high speed reclosure of mixed EHV lines is analysed, and means for limitation of the secondary arc current are examined. A protection scheme is proposed for fast selective detection of faults and for implementation of the single-pole reclosure only in the cases of 1-Phi-to-Gr faults in the overhead sections of mixed EHV lines
Keywords :
EMTP; XLPE insulation; arcs (electric); on load tap changers; power cable insulation; power overhead lines; reactive power; transformer windings; 380 kV; 50 Hz; 500 kV; 60 Hz; EHV transmission lines; EMTP electromagnetic transient analysis; XLPE-insulated cables sections; cable insulation; fault detection; onload tap changer; optimal voltage-reactive power control; overhead sections; overvoltages; power carrying capacity; secondary arc current; shunt compensation; shunt reactors; single-pole high speed reclosure; Cable insulation; Europe; Inductors; On load tap changers; Power cable insulation; Power cables; Power control; Power overhead lines; Power transmission lines; Shunt (electrical); Cable ampacity; EHV AC cables; mixed overhead -cable lines; overvoltages; resonance; shunt compensation; single-pole reclosure; voltage and reactive power control;
Conference_Titel :
Power Engineering Conference, 2005. IPEC 2005. The 7th International
Conference_Location :
Singapore
Print_ISBN :
981-05-5702-7
DOI :
10.1109/IPEC.2005.206934
