1. Ideal protection criteria

In the event of an electrical disturbance, the ideal protection element (or suppressor) must immediately limit the voltage to below the maximum permissible voltage for the protected circuit. In addition, it must consume minimum energy in steady state and maximum energy during a disturbance.

Circuit protectors can be placed either in series or in parallel with the circuit under consideration.

• Series protection covers three classes of devices:

  • fuses, switches and commutators, which react slowly and insensitively;

  • filters, which operate within a given frequency range and cannot protect against a wide variety of disturbances; it should be noted, however, that a filter, considered as a series element, is most often made up of a set of simple...