The Effect of High-Temperature Superconducting Current Limiters on Short-Circuit Fault Clearing

The article considers the influence of high-temperature superconducting (HTS) current limiters (CLs) on the requirements for peak withstand current, short-term withstand current, and breaking capacity of high-voltage circuit breakers in clearing single-phase short-circuit faults in 110-kV cable lines and estimates the influence of HTS CLs on transient recovery voltages (TRVs). Predicted and field oscillograms are compared with each other. In the case of using HTS CLs, it becomes possible to considerably reduce the requirements for high-voltage circuit breakers in terms of peak and short-term withstand current and breaking capacity, including the TRV peak and rate-of-change values. An alternative way for reducing the TRV peak and rate-of-change values, which makes it possible in many cases to do without expensive HTS CLs, is to use high-voltage circuit breakers fitted with shunt resistors. With such a solution, it becomes possible to not increase the automatic reclosing dead time caused by the need to cool the HTS CL after its actuation. The use of HTS CLs may be justified at high-capacity power plants and trunk substations with the level of short-circuit currents higher than 40 kA.