Influence of UHV hybrid reactive power compensation on interrupting characteristics of circuit breakers in the event of phase-to-phase faults

This paper presents a theoretical study of the interrupting characteristics of circuit breakers in the event of phase-to-phase faults in UHV transmission lines with hybrid reactive power compensation (HRPC). The study uses the transmission line parameters of the Jindongnan-Nanyang-Jingmen UHV AC pilot demonstration project in China and establishes a simplified model for the distribution parameters of transmission lines. Mathematical expressions describing the relationships between circuit breaker interrupting parameters and compensation degrees of HRPC are derived. Based on these mathematical expressions and their comparisons with simulation results, the effects of HRPC on circuit breaker interrupting characteristics and on the parameters of the phase-to phase fault circuit are determined, in which case the validity of the analytical method is verified. The results of this study will provide a theoretical foundation for practical implementation of HRPC in UHV transmission.