초록 ▼

An electric machine including a magnetic component, forming part of its rotor or stator that loses its magnetic characteristics above a certain chosen temperature is disclosed. This magnetic material forms part of a magnetic circuit that guides flux about the stator. As a result, any magnetic flux e

An electric machine including a magnetic component, forming part of its rotor or stator that loses its magnetic characteristics above a certain chosen temperature is disclosed. This magnetic material forms part of a magnetic circuit that guides flux about the stator. As a result, any magnetic flux emanating with the rotor stops circulating about the stator above this temperature, and the machine stops acting as generator. The component is thermally coupled to windings carrying current from the machine's stator. The material forming the component is selected so that the chosen temperature is lower than the temperature at which the machine would be thermally damaged. This, in turn, limits the operating temperature of the windings, and thus prevents overheating of the machine during operation, typically caused by a fault. Preferably this magnetic material is formed from a ferrite material, such as a Manganese Zinc ferrite material.

대표청구항 ▼

[ What is claimed is:] [16.]16. An electric generator comprising:a rotating rotor assembly comprising a permanent magnet;a stator formed of a ferrite material mounted about said rotor assembly, at least partially forming a magnetic circuit guiding a magnetic field emanating from said permanent magne

[ What is claimed is:] [16.]16. An electric generator comprising:a rotating rotor assembly comprising a permanent magnet;a stator formed of a ferrite material mounted about said rotor assembly, at least partially forming a magnetic circuit guiding a magnetic field emanating from said permanent magnet;at least one winding about said stator forming part of an electric circuit for picking up a current induced by said magnetic field;said winding thermally coupled to said stator so that a short circuit in said electric circuit heating said winding above a Curie temperature heats said stator above said Curie temperature and limits said magnetic field in said magnetic circuit above said Curie temperature, thereby limiting operating temperature of said winding, and preventing thermal damage to said generator and said winding in the presence of said short circuit;an induced current in said winding, induced by rotation of said rotor assembly.