Loadability Increase in Radial Transmission Lines through Reactive Power Injection

This paper investigates the loadability increase that can be obtained in radial transmission lines by means of a synchronous condenser connected at the receiving end of the line. In this configuration, the reactive power reserve at the receiving node can be used (at least in the best part) to control the reactive power flow in the radial line. This way, the voltage drop across the line can be controlled, avoiding to exceed the maximum voltage drop allowed. The result is a considerable increase of the loadability curves in the voltage drop region and, thus, a considerable power capability increase for medium length and long radial transmission lines. In order to accommodate growing load power, the use of a synchronous condenser can be a convenient alternative to the construction of a new line or to the doubling of a single-circuit line.