This paper presents the basic application idea of HTS (High-Temperature Superconducting) cable to solve the congestion problem of transmission line limited by voltage stability. In Korea power system, the capability of transmission system is limited by the voltage stability, and the HTS cable could be one of the countermeasures to enhance the transfer limit as its higher current capacity and lower impedance. However, the quench characteristic of HTS cable not only makes HTS cable to lose its superconductivity, but also change the line impedance and power system operating condition dramatically. This phenomenon threats the HTS cable safety as well as power system security, therefore a proper protection scheme and security control countermeasures have to be established before HTS cable implementation. In this paper, the quench characteristics of HTS cable for the fault current based on heat balance equation was established and a proper protection method by FCL(Fault Current Limiter) was suggested.