Evaluation of voltage and current profiles and Joule losses for a half-wavelength power transmission line

• Phasors are graphically presented along a half-wavelength transmission line (HWLL).
• The phasors clarify the voltage and current profiles for HWLL.
• An algebraic expression for Joule losses in HWLL is proposed and validated.
• Joule losses can be evaluated without power flow simulations.
• The algebraic expression facilitates the economical evaluation of the HWLL.

Half-wavelength lines (HWLLs) have been studied as an option to be applied to power transmission regarding line lengths around 2500 km for a 60 Hz frequency. The main advantage of this type of transmission line, which has not yet been put in commercial operation in any country, is the elimination of reactive compensation, which contributes to cost reduction if compared to a conventional ac transmission. This paper presents a demonstration of voltage and current magnitude profiles along the line, using phasors and graphic calculations. In addition, an algebraic expression for Joule losses is proposed, to be used in economical evaluation of a HWLL solution.