The performance of a medium ring transmission line at steady state

This paper presents the performance of the ring connection in transmission systems for medium lengths of a line under steady state operation. This wil l have more significant value especially if the transmitted power is a bulk amount. The ring connection between the phases of single circuit transmiss ion in the form of cumulative connection (capacitive/inductive) impedance i s accounted. The mathematical analysis is derived on the basis of Pi equiva lent circuit. The improvement of transmission performance is tried concerni ng the power factor either leading or lagging and loads. The earth path eff ect on transmission line parameters (resistance, inductance and capacitance ) is included through the phase shift control. The medium length for such l ines on the basis of sequential ring connection impedances is tested. The e ffect of load variation is investigated with the appearance of the shunt ca pacitive stray currents due to the increased length of the line. The ring a llocation as a ratio of the total line length is tested. The node voltages and branch currents of the sending (first) and ring as well as the receivin g (second) circuits are computed. Active and reactive powers at both sendin g and receiving ends of the proposed system are evaluated and then the tran smission efficiency is determined. The effect of load impedance in the per- unit system is studied and resulting variation in the transmission capabili ty is deduced. (C) 2000 Elsevier Science S.A. All rights reserved.