초록 ▼

The electric machine comprises at least one winding made of a material having a temperature dependent resistance. The temperature of the winding is monitored using the resistance therein. Temperatures or resistances indicative of a fault can be sensed, and corrective action taken, without the need f

The electric machine comprises at least one winding made of a material having a temperature dependent resistance. The temperature of the winding is monitored using the resistance therein. Temperatures or resistances indicative of a fault can be sensed, and corrective action taken, without the need for dedicated temperature sensors.

대표청구항 ▼

1. A method for monitoring an electric machine comprising a rotor and a stator, the stator having a primary set of stator windings configured to provide an electrical output of the machine and a secondary set of series-connected stator windings electrically isolated from the primary set of stator wi

1. A method for monitoring an electric machine comprising a rotor and a stator, the stator having a primary set of stator windings configured to provide an electrical output of the machine and a secondary set of series-connected stator windings electrically isolated from the primary set of stator windings, the secondary set of series-connected stator windings being distributed around at least a portion of the stator and configured to control the electrical output of the primary set of stator windings, the method comprising: operating the machine by rotating the rotor to generate the electrical output with the primary set of stator windings and providing a DC input current to the secondary set of series-connected stator windings to control the electrical output of the primary set of stator windings;determining a resistance across the secondary set of series-connected stator windings while the machine is in operation, the resistance determined from the DC current in the secondary set of series-connected stator windings and a DC voltage drop across the secondary set of series-connected stator windings;estimating a temperature of the secondary set of series-connected stator windings using the resistance determined; anddetermining the presence of a machine fault condition by comparing the estimated temperature against a selected threshold condition indicative of a fault. 2. The method of claim 1 further comprising the step of taking a corrective action based on a determination that a fault is present. 3. The method of claim 1 further comprising using the estimated temperature and the comparison information to determine a suitable corrective action. 4. The method of claim 1, further comprising the step of obtaining trend information over time by storing the estimated temperature over time. 5. The method of claim 4 further comprising using the trend information to predict a future maintenance event. 6. The method of claim 4 further comprising using the estimated temperature and the comparison information to suggest a possible suitable maintenance action. 7. A system for monitoring an electric machine, the system comprising: a rotor, a stator, a primary set of stator windings disposed in the stator and configured to conduct electricity induced by rotor rotation, and a plurality of secondary series-connected control windings disposed in the stator and electrically isolated from the primary set of stator windings, the secondary series-connected control windings being configured to permit regulation of said electricity in the primary stator windings upon the application of DC current to the secondary series-connected control windings;a monitor adapted for monitoring a DC voltage across the secondary series-connected control windings and a DC current across the secondary series-connected control windings; anda processor adapted to calculate an instantaneous estimated temperature of the secondary series-connected control windings based on the instantaneous DC voltage and DC current, and to determine the presence of a fault condition based on the instantaneous estimated temperature. 8. The method of claim 1 wherein the fault is a short circuit in the secondary set of stator windings.