Short-Circuit Protection of High-Speed Permanent Magnet Synchronous Generators

Abstract

The article considers the specific features of electromagnetic and electromechanical processes triggered by abrupt short-circuit faults (SCs) in self-contained power-generating installations equipped with high-speed synchronous permanent magnet turbine generators. Possible short-circuit fault occurrence places are analyzed, including those inside the turbine generators or at its terminals, between the turbine generator and frequency converter, in the frequency converter, and after the converter in the ship power mains. It is pointed out that measures to slow down the turbine generator rotor must be taken to decrease the current if a short-circuit fault occurs inside the turbine generator or at its terminals. The rotor is slowed down by supplying water into the stator bore cavity. In this case, the short circuit clearing time is commensurable with that in conventional turbine generators, the short-circuit current in which is decreased by killing the field current. In other cases, the protection from short-circuit faults is ensured by switching apparatuses.