Current-limiting reactors are series reactors intended to reduce the short circuit currents in the power system. The motive to reduce the short circuit currents in the is to use circuit breakers with lower short circuit current breaking capacity and consequently less expensive circuit breakers.
Sometimes other system components also need protection against too high short circuit currents, like for instance auto connected transformers that are not self-protecting due to their low impedance.
Another application is limitation of the inrush current when starting large motors.
Current-limiting reactors are sometimes used to limit discharge currents of capacitor banks. In such cases, a bifilar wound resistance wire is induced and connected in parallel with the inductance.