Study on the steady-state reactive power compensation of half-wavelength transmission lines considering the influences of the equivalent power supply impedance

Abstract

When a lossless half-wavelength AC transmission (HWACT) line is connected with an infinite power system, the voltage at the sending end, in the steady state, equals to the voltage at the receiving end in amplitude, and there is no need to install any reactive power compensation equipment for the transmission line. However, in the actual system, due to the influences of the equivalent power supply impedance, the electrical distance of the HWACT line has been extended, and the steady-state characteristics and the reactive power balance have been destroyed. Therefore, a strategy for reactive power compensation of the HWACT line is explored in this paper. Operation characteristics of the transmission line with control modes of constant voltage and constant power factor at the receiving end are explored by contrast, and the calculation method of reactive power compensation capacity in constant voltage control mode is given. The results show that the constant voltage control mode at the receiving end can significantly improve the transmission capacity of the HWACT system.