Flux probe for electric generator

• US 20050264110A1
• Filed: 05/27/2004
• Published: 12/01/2005
• Est. Priority Date: 05/27/2004
• Status: Active Grant

• Current Assignee: Siemens Energy Incorporated (Siemens AG)
• Original Assignee: Siemens Westinghouse Power Corporation
• Inventors: Dailey, George F., Humphries, Benjamin Todd, Morgan, William Gene
• Granted Patent: US 7,098,560 B2
• Time in Patent Office: Days
• US Class Current: 310/68.B
• CPC Class Codes: G01R 31/346 Testing of armature or field windings
• CPC Class Codes: G01R 31/52 Testing for short-circuits, leakage current or ground faults
• CPC Class Codes: H02K 11/00 Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection casings, enclosures or supports H02K5/00
• CPC Class Codes: H02K 3/487 Slot-closing devices

Abstract

A flux probe (100) for measuring the rotor flux of an electric generator (10). The probe (100) is affixed to a probe carrier (102) and held within a stator coil slot (62) by affixing the carrier (102) to two opposing grooves (104) formed in sidewalls (81) of the slot (62). One or more stator coils (18) are also disposed in the slot (62) and retained therein by a wedge (74) and corresponding spring (72) that applies an radially outwardly directed force to the coils (18). In one embodiment the probe carrier (102) is affixed to a radially inwardly directed face (82) of the wedge (74).

Claims

1. An apparatus for measuring magnetic flux in a dynamoelectric machine, wherein the machine comprises a cylindrical stator core defining an annular opening and a plurality of radially inwardly directed teeth disposed on an opening circumference, and wherein two adjacent teeth define a cavity therebetween for receiving a stator coil and a wedge, and wherein the wedge comprises a radially inwardly directed face, and is frictionally engaged with opposed cavity sidewalls for retaining the stator coil in the slot, the apparatus comprising:

a carrier;

a flux probe mated to the carrier; and

wherein the carrier is fixedly retained within the slot.

2. The apparatus of claim 1 wherein the carrier is attached to either the opposed cavity sidewalls or the wedge face.

3. The apparatus of claim 1 wherein at least one of the cavity sidewalls further defines a groove therein, and wherein the carrier comprises at least one beveled side surface for positioning within the groove.

4. The apparatus of claim 1 wherein each of the opposed cavity sidewalls defines a groove therein, and wherein the carrier comprises two opposed beveled side surfaces each disposed within one of the opposed sidewall grooves.

5. The apparatus of claim 4 wherein each beveled side surface is bonded to a corresponding sidewall groove.

6. The apparatus of claim 1 wherein the carrier is radially spaced-apart from the wedge, the apparatus further comprising a bladder disposed between a lower surface of the carrier and the wedge face, wherein the bladder receives a curable material that upon curing exerts a force against the carrier to retain the carrier within the slot.

7. The apparatus of claim 1 wherein the carrier comprises a plurality of linearly aligned segments each segment comprising a wedge-shaped surface for contacting a mating wedge-shaped surface of the adjacent segment, each segment further defining an axial opening therein for receiving a fastener, wherein application of an axially directed force to the fastener displaces the wedge-shaped surfaces from the linear alignment, such that a force is exerted against the opposed cavity sidewalls to retain the carrier within the slot.

8. A method for measuring magnetic flux in an electric generator wherein the generator comprises a cylindrical stator core defining an opening therein for receiving a rotor producing a magnetic field, and wherein the stator core further comprises a plurality of inwardly-directed coil slots disposed around a circumference of the opening, and wherein each slot defines a first pair of grooves disposed on opposing sidewalls of the coil slot, and wherein at least one coil is positioned in the coil slot and retained within the slot by a stator wedge disposed in the first pair of grooves, the method comprising:

inserting a flux probe within a slot, wherein the flux probe is positioned radially inwardly from the wedge; and

retaining the flux probe in the slot.

9. The method of claim 8 wherein the step of retaining comprises attaching the flux probe to a radially inwardly directed surface of the wedge.

10. The method of claim 8 wherein each slot further defines a second pair of grooves, and wherein the step of retaining comprises positioning the flux probe in the second pair of grooves for retaining the flux probe in the slot.

11. The method of claim 10 wherein the step of retaining further comprises bonding the flux probe to each of the second pair of grooves.

12. The method of claim 10 further comprising inserting a bladder in an opening formed between the flux probe and the wedge and injecting a curable material into the bladder such that upon curing the bladder exerts an inwardly directed force against the flux probe for retaining the flux probe in the slot.

13. The method of claim 8 wherein the flux probe is attached to a carrier, and wherein the method further comprises affixing the carrier to a radially inwardly directed surface of the wedge.

14. The method of claim 8 wherein the flux probe is attached to a carrier comprising a plurality of linearly aligned segments each segment further comprising a wedge-shaped surface for contacting a mating wedge-shaped surface of the adjacent segment, each segment further defining an axial opening therein for receiving a fastener, the method further comprising applying an axially directed force to the fastener to displace the wedge-shaped surfaces from linear alignment such that a force is exerted against the opposed cavity sidewalls to retain the carrier within the slot.