Rotary electrical synchronous machine

摘要

The supply for excitation of a synchronous machine is switched on or off before a critical RPM is reached when the machine is rotated at high speed or while braking. The critical RPM is the resonance speed of the cut-off (n2) or excited (n1) rotor. The supply switching occurs in between the two resonance speeds, esp. at the intersection of the two resonance curves. The synchronous machine is a rotor or generator. The braking or acceleration of the synchronous machine is carried out using a auxiliary pony-motor before the resonance rpm (n2) for braking and before the resonance rpm (n1) for acceleration.