STATOR OF AN ELECTRICAL MACHINE AND AN ELECTRICAL MACHINE

• US 20130285487A1
• Filed: 10/17/2011
• Published: 10/31/2013
• Est. Priority Date: 10/18/2010
• Status: Active Grant

• Current Assignee: Lappeenrannan Teknillinen Yliopisto
• Original Assignee: Lappeenrannan Teknillinen Yliopisto
• Inventors: Pyrhnen, Juha, Nerg, Janne, Jussila, Hanne, Alexandrova, Yulia, Polikarpova, Maria, Semken, Robert Scott, Rytt, Pekka
• Granted Patent: US 9,712,011 B2
• Time in Patent Office: Days
• US Class Current: 310/54
• CPC Class Codes: H02K 15/0414 Windings consisting of separate elements, e.g. bars, hairpins, segments, half coils
• CPC Class Codes: H02K 15/065 Windings consisting of complete sections, e.g. coils, waves windings for large electric machines other than those consisting of cables H02K15/063
• CPC Class Codes: H02K 15/066 inserted perpendicularly to the axis of the slots or inter-polar channels
• CPC Class Codes: H02K 2213/03 Machines characterised by numerical values, ranges, mathematical expressions or similar information
• CPC Class Codes: H02K 2213/12 Machines characterised by the modularity of some components
• CPC Class Codes: H02K 3/18 Windings for salient poles
• CPC Class Codes: H02K 3/22 consisting of hollow conductors
• CPC Class Codes: H02K 3/24 with channels or ducts for cooling medium between the conductors
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction

Abstract

A stator of an electrical machine that is straightforward to assemble and for which an efficient liquid cooling can be arranged includes a stator core (801) having a plurality of stator teeth and stator slots, and a stator winding having a plurality of stator coils (803). The width of each stator coil is one stator slot pitch, and the stator teeth are shaped to allow each stator coil to be installed by pushing the stator coil to surround one of the stator teeth. The stator coils include tubular cooling channels (804) for conducting cooling liquid in the stator slots. The stator winding is designed by taking into account the aspects related to the liquid cooling, and it has been noticed that a stator winding structure which is advantageous for arranging the liquid cooling has satisfactory electrical and magnetic properties too.

Claims

1-16. -16. (canceled)

17. A stator for an electrical machine, the stator comprising:

a stator core comprising a plurality of stator teeth and stator slots, and

a stator winding comprising a plurality of stator coils,

wherein width of each stator coil is one stator slot pitch, and the stator teeth are shaped to allow each stator coil to be installed by pushing the stator coil to surround one of the stator teeth without changing the shape of the stator coil, and the stator coils comprise tubular cooling channels for conducting cooling liquid in the stator slots in the longitudinal direction of electrical conductors of the stator coils.

18. A stator according to claim 17, wherein the electrical conductors of the stator coils are tubular so as to form the tubular cooling channels.

19. A stator according to claim 17, wherein the stator coils comprise cooling tubes made of different material than the electrical conductors of the stator coils and attached to the electrical conductors of the stator coils, the cooling tubes forming the tubular cooling channels.

20. A stator according to claim 19, wherein each electrical conductor comprises two electrically parallel connected bars of electrically conductive material and one of the cooling tubes is placed between the bars.

21. A stator according to claim 19, wherein each electrical conductor comprises a sleeve of electrically conductive material arranged to surround one of the cooling tubes.

22. A stator according to claim 19, wherein each electrical conductor comprises a bundle of electrically parallel connected wires of electrically conductive material, the bundle being arranged to surround one of the cooling tubes, and the stator coils further comprising electrical insulator material between the wires of the electrically conductive material.

23. A stator according to claim 19, wherein each stator coil comprises two cooling tubes which constitute parallel paths for the cooling liquid and the electrical conductors attached to these two cooling tubes are electrically series connected.

24. A stator according to claim 19, wherein the cooling tubes are made of stainless steel.

25. A stator according to claim 19, wherein the stator coils comprise electrically insulating connecting elements at the ends of the cooling tubes.

26. A stator according to claim 17, wherein the electrical conductors of the stator coils are made of copper.

27. A stator according to claim 17, wherein the stator core consists of a plurality of stator segments.

28. A stator according to claim 17, wherein the stator winding is coated with a layer of resin so as to protect the stator winding against external stresses.

29. A stator according to claim 17, wherein the stator is one of the following:

a stator of an inner rotor radial flux machine, a stator of an outer rotor radial flux machine, a stator of an axial flux machine.

30. An electrical machine comprising a rotor and a stator that comprises:

a stator core comprising a plurality of stator teeth and stator slots, and

a stator winding comprising a plurality of stator coils,

wherein width of each stator coil is one stator slot pitch, and the stator teeth are shaped to allow each stator coil to be installed by pushing the stator coil to surround one of the stator teeth without changing the shape of the stator coil, and the stator coils comprise tubular cooling channels for conducting cooling liquid in the stator slots in the longitudinal direction of electrical conductors of the stator coils.

31. An electrical machine according to claim 30, wherein the rotor comprises permanent magnets for producing an excitation magnetic flux.

32. An electrical machine according to claim 31, wherein the number (p) of magnetic poles produced with the permanent magnets is greater than the quotient of the number (Q) of the stator teeth and the number of phases (m) of the stator winding, Q/m/p<

1.