Capacitance Current Compensation Method for Cable-Overhead Hybrid Transmission Lines

At present, the capacitance current compensation technology for transmission line differential protection is based on uniform parameters of entire lines, so it cannot be adapted to cable-overhead hybrid transmission lines. In this paper, a steady-state compensation method based on segment parameters, a time-domain compensation method based on whole line equivalent parameters and a time-domain compensation method based on segment parameters are proposed, which can adapt to different application scenarios, such as hybrid lines with shunt reactance at the ends and junctions. A PSCAD/EMTDC simulation shows that when a hybrid transmission line is short, the time-domain compensation method based on whole line equivalent parameters is simple to implement, and it can effectively compensate the capacitance current of hybrid transmission lines. The time-domain compensation method based on segment parameters can accurately compensate the capacitance current of hybrid transmission lines, taking into account the reliability and sensitivity of differential protection.