Series current limiter with varistor for high voltage transmission line - has parallel third coil with varistor and series compensation capacitor having second varistor and discharger across terminals

摘要

The current limiter is in series with a HV line circuit breaker (13). It has parallel first and second conducting coils (E1,E2) with more tuns on the second coil forming a closed magnetic cam of variable cross-section in a circuit that saturates on default. The coils are oppositely wound creating a drop in the permanent induced voltage equal to 3-6% of the nominal earth phase line voltage. The third coil (E3) is wound in the same direction as the second coil with more tuns than the first. It has a series varistor (15) which operates when the fault current is 3In(root 2) times the nominal limiter circuit. The second varistor (7) operates at the same current and the discharger (8) operates several milliseconds later. USE/ADVANTAGE - Protection of line against high short-circuit currents. Improved magnetic saturation and cancels voltage across limiter terminals in continuous rating.