Stator winding arrangement

Patent metadata

Field	Value
Publication number	US-12249882-B2
Application number	US-202017594221-A
Country	US
Kind code	B2
Filing date	Apr 8, 2020
Priority date	Apr 9, 2019
Publication date	Mar 11, 2025
Grant date	Mar 11, 2025

Abstract

An electrical machine for use in an aircraft, including a rotor. The rotor includes a plurality of rotor poles, and a stator including a plurality of phases. Each respective phase occupies at least one elementary block and the at least one elementary block of each phase includes a set of conductors of the respective phase wound around a plurality of slots of the respective elementary block in a concentrated winding configuration. A mechanical shift angle between the respective concentrated windings of each pair of adjacent elementary blocks is greater than a rotor pole pitch. The rotor pole pitch is an angle between adjacent poles of the rotor.

First claim

The invention claimed is:

1. An electrical machine for use in an aircraft, comprising:
a rotor, wherein the rotor comprises a plurality of rotor poles; and
a stator comprising a plurality of phases, wherein each respective phase occupies at least one elementary block, the at least one elementary block of each phase comprising a set of conductors of the respective phase wound around a plurality of slots of the respective elementary block in a concentrated winding configuration;
wherein a mechanical shift angle between the respective concentrated windings of each pair of adjacent elementary blocks is greater than a rotor pole pitch, the rotor pole pitch being an angle between adjacent poles of the rotor; and
wherein each elementary block comprises a plurality of slots arranged to house two conductors of the respective concentrated winding to define an inner layer and an outer layer, and wherein the stator further comprises a further intermediate slot arranged to house one conductor configured to provide a return path connecting the inner layer and the outer layer of each respective elementary block.

2. The electrical machine according to claim 1 , wherein the mechanical shift angle is defined by a function of the rotor pole pitch, a total number of slots in the stator, and a number of elementary blocks in the stator.

3. The electrical machine according to claim 2 , wherein the mechanical shift angle is calculated using a first equation comprising a multiplier and a denominator, wherein the rotor pole pitch, the total number of slots in the stator, and the number of elementary blocks in the stator are variables of the first equation, wherein the multiplier is defined as: the number of elementary blocks subtracted from the total number of slots to output a first multiplier value, the first multiplier value being multiplied by the rotor pole pitch to output a second multiplier value, the second multiplier value being subtracted from a constant.

4. The electrical machine according to claim 3 , wherein the denominator is the number of elementary blocks.

5. The electrical machine according to claim 2 , wherein the mechanical shift angle, δ ph , is calculated by:

δ
ph

=

360
-

τ
p

⁡

(

N
slot

-
n

)

n

where:
N slot is the total number of slots in the stator;
n is the number of elementary blocks in the stator; and
T p is the rotor pole pitch.

6. The electrical machine according to claim 2 , wherein the total number of elementary blocks, n, is equal to 3 or 6.

7. The electrical machine according to claim 2 , wherein the total number of slots in the stator and a total number of rotor poles are selected in dependence on a predetermined condition, wherein the predetermined condition is a function of the mechanical shift angle and the rotor pole pitch.

8. The electrical machine according to claim 7 , wherein the predetermined condition requires that the total number of slots and the total number of rotor poles correspond to a mechanical shift angle and a rotor pole pitch that satisfy a second equation, wherein the rotor pole pitch and the mechanical shift angle are variables of the second equation, wherein the second equation comprises calculating a floor function of the mechanical shift angle divided by the rotor pole pitch, wherein the floor function rounds a product of the mechanical shift angle divided by the rotor pole pitch to a nearest integer less than or equal to the product to output a first condition value.

9. The electrical machine according to claim 8 , wherein the second equation further comprises multiplying the first condition value by the rotor pole pitch to output a second condition value, wherein the second equation further comprises subtracting the second condition value from the mechanical shift angle to output a third condition value, wherein the predetermined condition is satisfied if the third condition value is equal to a fraction of the rotor pole pitch, and wherein the fraction of the rotor pole pitch is a third of the rotor pole pitch or two thirds of the rotor pole pitch.

10. The electrical machine according to claim 8 , wherein the second equation is defined as:

[

δ
ph

-

floor
⁡

(

δ
ph

τ
p

)

⁢

τ
p

]

=

τ
p

3

⁢

⁢
or
⁢

⁢

2
⁢

τ
p

3

where:
δ ph is the mechanical shift angle;
T p is the rotor pole pitch; and

floor
⁡

(

δ
ph

τ
p

)

is a floor function that rounds the product of

(

δ
ph

τ
p

)

to the nearest integer less than or equal to that product.

11. The electrical machine according to claim 7 , wherein the total number of slots in the stator is less than the total number of rotor poles.

12. The electrical machine according to claim 1 , wherein each phase comprises

Assignees

• Centre Nat Rech Scient
• Safran Electrical & Power
• Safran Landing Systems

Inventors

• Boubaker Nadhem
• Matt Daniel
• Nierlich Florent

Classifications

• H02K2213/03

  Machines characterised by numerical values, ranges, mathematical expressions or similar information · CPC title

• H02K3/12

  arranged in slots · CPC title

• H02K1/165 Primary

  Shape, form or location of the slots · CPC title

• H02K21/16

  having annular armature cores with salient poles (with homopolar co-operation H02K21/20) · CPC title

• H02K3/28 Primary

  Layout of windings or of connections between windings (windings for pole-changing H02K17/06, H02K17/14, H02K19/12, H02K19/32) · CPC title