Cross transposition method of hairpin coil alternating current winding formed by winding two flat copper enameled wires in parallel

Abstract

The invention discloses an alternating-current winding which is suitable for 48-slot 4-pole dual three-phase Y-connection phase shift of 30 degrees, the slot number of each phase of each pole is 2, each phase comprises four parallel branches, the number of series turns of a coil of each parallel branch is 8, and a hairpin coil is formed by combining two flat copper enameled wires and winding a wave winding. When the front four hairpin coils in each parallel branch are connected in series and the rear four hairpin coils in each parallel branch are connected in series, two parallel winding flat copper enameled wire conductors in the coils do not need to be subjected to transposition, namely, the lower layer conductors and the lower layer conductors in the four hairpin coils are connected in series through welding, and the upper layer conductors and the upper layer conductors in the four hairpin coils are connected in series through welding; the tail end of the lower layer conductor and the tail end of the upper layer conductor in the backmost hairpin coil in the front four hairpin coils connected in series are respectively connected with the head end of the upper layer conductor and the head end of the lower layer conductor in the foremost hairpin coil in the rear four hairpin coils connected in series through welding. The cross transposition of the upper layer conductor and the lower layer conductor of each parallel branch of each phase is realized, and the coil edge of the cross transposition is located at the eighth layer in the slot.

Description

Technical Field

[0001] The invention belongs to the field of electrical engineering and relates to a hairpin coil AC winding cross-transposition method which is suitable for 48-slot 4-pole double three-phase Y-connection with a phase shift of 30°, 2 slots per pole per phase, 4 parallel branches per phase, 8 turns of coil series connection in each parallel branch, and is wound by two flat copper enameled wires. Background Art

[0002] Permanent magnet synchronous motors are widely used in flywheel energy storage technology, and the power of the permanent magnet synchronous motors used is getting larger and larger, the motor voltage and speed are getting higher and higher, and the demand for multi-phase and hairpin windings is becoming more and more prominent. When high-speed multi-phase permanent magnet synchronous motors for high-power flywheel energy storage use hairpin windings, the coils of the hairpin windings have to be wound with two flat copper enameled wires. At this time, a relatively simple, fast and effective transposition technology must be used to reduce the circulating current between the two flat copper enameled wires and reduce the additional copper loss of the winding. At the same time, it is also hoped that the axial height of the end of the winding is as short as possible. Summary of the invention

[0003] In order to solve the technical problem that a hairpin winding is used in a high-speed multi-phase permanent magnet synchronous motor for high-power flywheel energy storage, and the coil of the hairpin winding is wound with two flat copper enameled wires in parallel, a relatively simple, fast and effective transposition method must be adopted, and the axial height of the end must be as short as possible, the present invention proposes a cross-transposition method for an AC winding in which a hairpin coil is wound with two flat copper enameled wires in parallel.

[0004] The present invention provides a method for cross-transposing an AC winding in which a hairpin coil is wound in parallel with two flat copper enameled wires, and is characterized in that:

[0005] This method is applicable to 48-slot 4-pole double three-phase Y-connection with a phase shift of 30°, 2 slots per pole per phase, 4 parallel branches per phase, 8 turns of coil series connection in each parallel branch, and the hairpin coil is an AC winding composed of two flat copper enameled wires and a wave winding;

[0006] The two flat copper enameled wires wound in each hairpin coil are arranged in the slot with the lower conductor stacked on the upper conductor, and no insulation treatment is required between the lower conductor and the upper conductor; each hairpin coil is a wave winding coil with one turn and a first span of a long distance; in order to simplify the production and embedding process of the hairpin coil, the end of each hairpin coil wound by two flat copper enameled wires is only bent and twisted, and no position change is performed;

[0007] Each slot has 8 layers of hairpin coils wound with two flat copper enameled wires. There are 384 hairpin coils wound with two flat copper enameled wires in the 48 slots on the stator core, for a total of 192 hairpin coils.

[0008] When the slot numbers of the 48 slots are named counterclockwise from small to large, looking counterclockwise along the inner circumference of the stator core, the first slot encountered is the first slot in each positive phase band or negative phase band of the phase divided according to the phase division result, a total of 24 slots, the slot numbers S of these 24 slots are all odd numbers, and the two flat copper enameled wires are inserted into the Lth layer with an odd number of layers L in the slot with an odd number of slot numbers S and wound around the coil side of the head end of the hairpin coil. The head ends of the lower conductor and the upper conductor of the head end of the coil side of the hairpin coil are respectively recorded as and And the first span of these coils is y 1，1 =15 slots, y 1，1 The slot number is greater than the motor pole pitch τ = 12 slots, and the tail coil sides of these coils are all located at slot number (S+y 1，1 ), the layer number (L+1) is an even number, these are in the slot number (S+y 1，1 The tail ends of the lower conductor and the upper conductor of the (L+1)th layer of the hairpin coil are respectively marked as and When the slot number (S+y 1，1 )>48, the corresponding slot number (S+y 1，1 ) is corrected to slot number (S+y 1，1 -48);

[0009] When the slot numbers of the 48 slots are named counterclockwise from small to large, looking counterclockwise on the circumference of the stator core, the first slot encountered is the second slot in each positive phase band or negative phase band of the phase divided according to the phase division result, for a total of 24 slots. The slot numbers S of these 24 slots are all even numbers. The two flat copper enameled wires are inserted into the Lth layer with an odd number of layers L in the slots with even numbers S and are wound around the coil side of the head end of the hairpin coil. The head ends of the lower conductor and the upper conductor of the coil side of the head end of the hairpin coil are respectively recorded as and And the first span of these coils is y 1，2 =13 slots, y 1，2 The slot number of the tail coil side of these coils is (S+y 1，2 ), the layer number (L+1) is an even number, these are in the slot number (S+y 1，2 The tail ends of the lower conductor and the upper conductor of the (L+1)th layer of the hairpin coil are respectively marked as and When the slot number (S+y 1，2 )>48, the corresponding slot number (S+y 1，2 ) is corrected to slot number (S+y 1，2 -48);

[0010] In each slot, the coil sides of the 1st, 2nd, 3rd, 4th, 5th, 6th, 7th and 8th layers of hairpin coils are inserted in sequence from the bottom of the slot to the slot mouth. Phase insulation needs to be done between the coil sides of each layer, and slot insulation needs to be done between the slots and the coil sides.

[0011] A1, B1, and C1 constitute a set of three-phase Y-connected symmetrical windings, and A2, B2, and C2 constitute another set of three-phase Y-connected symmetrical windings. The phase difference between the fundamental electromotive force of phase A1 and phase A2, phase B1 and phase B2, and phase C1 and phase C2 of the two sets of three-phase Y-connected symmetrical windings is 30° electrical angle; the number of slots per pole and phase is 2, and each phase has 4 parallel branches. Among them, the A1 phase winding is composed of 4 parallel branches: A1-1X1-1, A1-2X1-2, A1-3X1-3 and A1-4X1-4; the A2 phase winding is composed of 4 parallel branches: A2-1X2-1, A2-2X2-2, A2-3X2-3 and A2-4X2-4; the B1 phase winding is composed of 4 parallel branches: B1-1Y1-1, B1-2Y1-2, B1-3Y1-3 and B1-4Y1-4. The B2 phase winding is composed of 4 parallel branches: B2-1Y2-1, B2-2Y2-2, B2-3Y2-3 and B2-4Y2-4; the C1 phase winding is composed of 4 parallel branches: C1-1Z1-1, C1-2Z1-2, C1-3Z1-3 and C1-4Z1-4; the C2 phase winding is composed of 4 parallel branches: C2-1Z2-1, C2-2Z2-2, C2-3Z2-3 and C2-4Z2-4;

[0012] The number of coil series turns of each parallel branch of each phase is 8 turns, that is, 8 hairpin coils are connected in series in each parallel branch; when the front 4 hairpin coils are connected in series and the rear 4 hairpin coils are connected in series, the upper conductor and the lower conductor are not transposed, and the upper conductors and the lower conductors of the two coil sides of the tail ends and the head ends of the front and rear hairpin coils are connected together by welding one by one, and the second span is y2=10 slots, and each welding point is well insulated; the head end of each parallel branch of each phase is the head end of the head end coil side of the first hairpin coil among the front 4 hairpin coils connected in series, and the head end coil side of the first hairpin coil is at the bottom of the slot numbered S - the first layer;

[0013] When the first span of the first hairpin coil of each parallel branch of each phase is y 1，1 = 15 slots, the tail coil side of the first hairpin coil of this phase is at the slot number (S+y 1，1 ) in the second layer of the slot, the tail coil side of the first hairpin coil and the head coil side of the second hairpin coil are connected by a conductor without transposition, and the head and tail coil sides of the second hairpin coil are respectively in the slot number (S+y 1，1+y2) slot and the slot number is (S+y 1，1 +y2+y 1，2 ) in the 4th layer of the slot, the tail coil side of the 2nd hairpin coil is connected with the head coil side of the 3rd hairpin coil by winding the conductor without transposition, the head and tail coil sides of the 3rd hairpin coil are in the 5th layer of the slot with slot number S and the slot number (S+y 1，1 ) in the 6th layer of the slot, the tail end coil side of the 3rd hairpin coil is connected with the head end coil side of the 4th hairpin coil by winding the conductor without transposition, and the head end and tail end of the coil side of the 4th hairpin coil are respectively in the slot number (S+y 1，1 +y2) slot and the slot number is (S+y 1，1 +y2+y 1，2 ) in the 8th layer of the slot, then, the tail end of the first 4 series coils - the tail end coil side of the 4th hairpin coil and the head end of the last 4 series coils - the tail end coil side of the 5th hairpin coil are cross-transposed and connected, that is, the upper and lower conductors of the two flat copper enameled wires are cross-transposed and welded in series to weaken the circulating current between the two conductors when the two flat copper enameled wires in the parallel branch of the phase winding are wound in parallel, that is, the slot number (S+y 1，1 +y2+y 1，2 ) in the slot with the 8th layer of the 4th hairpin coil at the tail end of the coil and the conductor in the slot with the number (S+y 1，1 +y2+y 1，2 -y 3，1 ) in the slot of the 8th layer, the lower conductor of the tail coil side of the 5th hairpin coil is welded and connected in series, and the lower conductor of the tail coil side of the 4th hairpin coil and the upper conductor of the tail coil side of the 5th hairpin coil are welded and connected in series, so as to realize the cross-transposition of the upper and lower conductors and the lower and upper conductors in series of the front 4 hairpin coils and the rear 4 hairpin coils. The third span slot y between the front and rear coil sides during the cross-transposition 3，1 =τ-1=11, the cross-transposed coil sides are all in the 8th layer of the slot; when the following 4 hairpin coils are connected in series, the tail end coil side of the 5th hairpin coil is in the slot number (S+y 1，1 +y2+y 1，2 -y 3，1 ) in the slot of the 8th layer, the first end coil side of the 5th hairpin coil is in the slot number (S+y2+y 1，2 -y 3，1 ) in the 7th layer of the slot, the first end coil side of the 5th hairpin coil and the tail end coil side of the 6th hairpin coil are connected by conductors without transposition, and the tail end coil side of the 6th hairpin coil is in the slot number (S+y 1，2 -y 3，1 ) slot, the sixth layer, the first end coil side of the sixth hairpin coil is in the slot number (Sy3，1 ) in the fifth layer of the slot, the first coil side of the sixth hairpin coil and the tail coil side of the seventh hairpin coil are connected by a conductor without transposition, and the tail coil side of the seventh hairpin coil is in the slot number (S+y 1，1 +y2+y 1，2 -y 3，1 ) in the slot of the 4th layer, the first end coil side of the 7th hairpin coil is located at the slot number (S+y2+y 1，2 -y 3，1 ) in the third layer of the slot, the first end coil side of the 7th hairpin coil and the tail end coil side of the 8th hairpin coil are connected by conductors without transposition, and the tail end coil side of the 8th hairpin coil is in the slot number (S+y 1，2 -y 3，1 ) slot, the 2nd layer, the 8th hairpin coil head coil side is in the slot number (Sy 3，1 ) in the first layer of the slot, the head end of the head end coil side of the 8th hairpin coil is also the tail end of the parallel branch of this phase winding;

[0014] When the first span of the first hairpin coil of each parallel branch of each phase is y 1，2 = 13 slots, the tail coil side of the first hairpin coil of this phase is at the slot number (S+y 1，2 ) in the second layer of the slot, the tail coil side of the first hairpin coil and the head coil side of the second hairpin coil are connected by a conductor without transposition, and the head and tail coil sides of the second hairpin coil are respectively in the slot number (S+y 1，2 +y2) slot and the slot number is (S+y 1，2 +y2+y 1，1 ) in the 4th layer of the slot, the tail coil side of the 2nd hairpin coil is connected with the head coil side of the 3rd hairpin coil by winding the conductor without transposition, the head and tail coil sides of the 3rd hairpin coil are in the 5th layer of the slot with slot number S and the slot number (S+y 1，2 ) in the 6th layer of the slot, the tail end coil side of the 3rd hairpin coil is connected with the head end coil side of the 4th hairpin coil by winding the conductor without transposition, and the head end and tail end of the coil side of the 4th hairpin coil are respectively in the slot number (S+y 1，2 +y2) slot and the slot number is (S+y 1，2 +y2+y 1，1 ) in the 8th layer of the slot, then, the tail end of the first 4 series coils - the tail end coil side of the 4th hairpin coil and the head end of the last 4 series coils - the tail end coil side of the 5th hairpin coil are cross-transposed and connected in parallel with the conductor, that is, it is necessary to cross-transpose and weld the upper and lower conductors wound by two flat copper enameled wires in parallel to connect in series, so as to weaken the circulating current between the two conductors when the two flat copper enameled wires in the parallel branch of the phase winding are wound in parallel, that is, to connect the conductor in the slot number (S+y1，2 +y2+y 1，1 ) in the slot with the 8th layer of the 4th hairpin coil at the tail end of the coil and the conductor in the slot with the number (S+y 1，2 +y2+y 1，1 -y 3，2 ) in the slot of the 8th layer, the lower conductor of the tail coil side of the 5th hairpin coil is welded and connected in series, and the lower conductor of the tail coil side of the 4th hairpin coil and the upper conductor of the tail coil side of the 5th hairpin coil are welded and connected in series, so as to realize the cross-transposition of the upper and lower conductors and the lower and upper conductors in series of the front 4 hairpin coils and the rear 4 hairpin coils. The third span slot y during the cross-transposition 3，2 =τ+1=13, the coil sides of the cross-transposed coils are all in the 8th layer of the slot; when the following 4 hairpin coils are connected in series, the tail coil side of the 5th hairpin coil is in the slot number (S+y 1，2 +y2+y 1，1 -y 3，2 ) in the slot of the 8th layer, the first end coil side of the 5th hairpin coil is in the slot number (S+y2+y 1，1 -y 3，2 ) in the 7th layer of the slot, the first end coil side of the 5th hairpin coil and the tail end coil side of the 6th hairpin coil are connected by conductors without transposition, and the tail end coil side of the 6th hairpin coil is in the slot number (S+y 1，1 -y 3，2 ) slot, the first end coil side of the sixth layer and the sixth hairpin coil is in the slot number (Sy 3，2 ) in the fifth layer of the slot, the first coil side of the sixth hairpin coil and the tail coil side of the seventh hairpin coil are connected by a conductor without transposition, and the tail coil side of the seventh hairpin coil is in the slot number (S+y 1，2 +y2+y 1，1 -y 3，2 ) in the slot of the 4th layer, the first end coil side of the 7th hairpin coil is located at the slot number (S+y2+y 1，1 -y 3，2 ) in the third layer of the slot, the first end coil side of the 7th hairpin coil and the tail end coil side of the 8th hairpin coil are connected by conductors without transposition, and the tail end coil side of the 8th hairpin coil is in the slot number (S+y 1，1 -y 3，2 ) slot, the 2nd layer, the 8th hairpin coil head coil side is in the slot number (Sy 3，2 ) in the first layer of the slot, the head end of the head end coil side of the 8th hairpin coil is also the tail end of the parallel branch of this phase winding;

[0015] "∧" indicates the connection of the end conductor of a hairpin coil where the conductor at the head end coil side is connected to the conductor at the tail end coil side; "=" indicates that the lower conductor at the tail end coil side of the first hairpin coil of the first four series-connected hairpin coils and the last four series-connected hairpin coils in each parallel branch is connected with the lower conductor at the head end coil side of the last hairpin coil by welding, and the upper conductor at the tail end coil side of the first hairpin coil is connected with the upper conductor at the head end coil side of the last hairpin coil by welding, that is, "=" indicates that "the front and rear hairpin coil sides are connected". The upper and lower conductors do not need to be transposed when they are connected by welding”; “×” is used to indicate that the lower conductor at the tail coil side of the last hairpin coil among the first four series hairpin coils in each parallel branch is connected by welding with the upper conductor at the head coil side of the last hairpin coil among the last four series hairpin coils, and the upper conductor at the tail coil side of the first hairpin coil is connected by welding with the lower conductor at the head coil side of the last hairpin coil, that is, “×” is used to indicate that the upper and lower conductors at the sides of the front and rear hairpin coils need to be cross-transposed when they are connected by welding;

[0016] The connection between the upper conductor and the lower conductor between the coil sides of the hairpin winding conductor of each parallel branch of each phase is:

[0017] The connection sequence of the two parallel-wound conductor coils in the A1-1X1-1 parallel branch of the A1 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0019] The connection sequence of the two parallel-wound conductor coils in the A1-2X1-2 parallel branch of the A1 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0021] The connection sequence of the two parallel-wound conductor coils in the A1-3X1-3 parallel branch of the A1 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0023] The connection sequence of the two parallel-wound conductor coils in the A1-4X1-4 parallel branch of the A1 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0025] The connection sequence of the two parallel-wound conductor coils in the A2-1X2-1 parallel branch of the A2 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0027] The connection sequence of the two parallel-wound conductor coils in the A2-2X2-2 parallel branch of the A2 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0030] The connection sequence of the two parallel-wound conductor coils in the A2-3X2-3 parallel branch of the A2 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0033] The connection sequence of the two parallel-wound conductor coils in the A2-4X2-4 parallel branch of the A2 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0036] The connection sequence of the two parallel-wound conductor coils in the B1-1Y-1 branch of the B1 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0038] The connection sequence of the two parallel conductor coils in the B1-2Y1-2 parallel branch of the B1 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0041] The connection sequence of the two parallel conductor coils in the B1-3Y1-3 parallel branch of the B1 phase winding is: the first line, the first end end; Article 2, beginning Tail end.

[0044] The connection sequence of the two parallel-wound conductor coils in the B1-4Y1-4 parallel branch of the B1 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0047] The connection sequence of the two parallel conductor coils in the B2-1Y2-1 parallel branch of the B2 phase winding is: the first line, the first end end; Article 2, beginning Tail end.

[0050] The connection sequence of the two parallel-wound conductor coils in the B2-2Y2-2 parallel branch of the B2 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0053] The connection sequence of the two parallel-wound conductor coils in the B2-3Y2-3 parallel branch of the B2 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0056] The connection sequence of the two parallel conductor coils in the B2-4Y2-4 parallel branch of the B2 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0059] The connection sequence of the two parallel-wound conductor coils in the C1-1Z-1 branch of the C1 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0061] The connection sequence of the two parallel-wound conductor coils in the C1-2Z1-2 parallel branch of the C1 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0064] The connection sequence of the two parallel-wound conductor coils in the C1-3Z1-3 parallel branch of the C1 phase winding is: the first line, the first end end; Article 2, beginning Tail end.

[0067] The connection sequence of the two parallel conductor coils in the C1-4Z1-4 parallel branch of the C1 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0070] The connection sequence of the two parallel-wound conductor coils in the C2-1Z2-1 parallel branch of the C2 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0073] The connection sequence of the two parallel conductor coils in the C2-2Z2-2 parallel branch of the C2 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0076] The connection sequence of the two parallel-wound conductor coils in the C2-3Z2-3 parallel branch of the C2 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0079] The connection sequence of the two parallel conductor coils in the C2-4Z2-4 parallel branch of the C2 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0082] Finally, the parallel branches of each phase are connected in parallel to form a complete dual three-phase AC winding, X1-1, Y1-1 and Z1-1 are connected to form a Y-shaped star point N1-1; X1-2, Y1-2 and Z1-2 are connected to form a Y-shaped star point N1-2; X1-3, Y1-3 and Z1-3 are connected to form a Y-shaped star point N1-3; X1-4, Y1-4 and Z1-4 are connected to form a Y-shaped star point N1-4; N1-1, N1-2, N1-3 and N1-4 are not connected to each other. X2-1, Y2-1 and Z2-1 are connected to form a Y-shaped star point N2-1; X2-2, Y2-2 and Z2-2 are connected to form a Y-shaped star point N2-2; X2-3, Y2-3 and Z2-3 are connected to form a Y-shaped star point N2-3; X2-4, Y2-4 and Z2-4 are connected to form a Y-shaped star point N2-4; N2-1, N2-2, N2-3 and N2-4 are not connected to each other. A1-1, A1-2, A1-3 and A1-4 are connected to form the input end of the A1 phase winding; B1-1, B1-2, B1-3 and B1-4 are connected to form the input end of the B1 phase winding; C1-1, C1-2, C1-3 and C1-4 are connected to form the input end of the C1 phase winding; A1, B1 and C1 form a Y-connected three-phase winding with 4 parallel branches and 4 star points that are not connected to each other; A2-1, A2-2, A2-3 and A2-4 are connected together to form the input end of the A2 phase winding; B2-1, B2-2, B2-3 and B2-4 are connected together to form the input end of the B2 phase winding; C2-1, C2-2, C2-3 and C2-4 are connected together to form the input end of the C2 phase winding; A2, B2 and C2 constitute a Y-connected three-phase winding with 4 parallel branches and 4 star points that are not connected to each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] Figure 1 It is the star diagram of the slot electromotive force of a 48-slot, 4-pole, double three-phase Y-connected, 30° phase-shifted AC motor and its phase-splitting result according to the 30° phase band.

[0084] Figure 2 It is a schematic diagram of the cross section of the stator of a 48-slot, 4-pole, double-three-phase AC motor using two flat copper enameled wires wound with hairpin coils.

[0085] Figure 3 The diagram is a diagram showing the relationship between the layers of the coil sides of 8 hairpin coils wound with two flat copper enameled wire conductors in a slot and the position of the upper conductor and the lower conductor in each coil side.

[0086] Figure 4 It is a schematic diagram of the "slot numbers" and related "names and symbols" of the two slots where the two sides of the lower conductor of the hairpin coil are located in the stator winding expansion diagram.

[0087] Figure 5 It is a schematic diagram of the "equivalent circuit" and "name symbol" of the two sides of the upper conductor in the hairpin coil in the equivalent circuit diagram of the phase winding parallel branch.

[0088] Figure 6 It is a schematic diagram of the "slot numbers" and related "names and symbols" of the two slots where the two sides of the upper conductor of the hairpin coil are located in the stator winding expansion diagram.

[0089] Figure 7 It is a schematic diagram of the "equivalent circuit" and "name symbol" of the two sides of the lower conductor of the hairpin coil in the equivalent circuit diagram of the parallel branch of the phase winding.

[0090] Figure 8 It is a schematic diagram of 8 hairpin coil sides in a slot, which are wound by two flat copper enameled wire conductors, and their upper and lower conductors in the stator winding expansion diagram.

[0091] Fig. 9 It is an expanded diagram of the stator winding in which the upper and lower conductors of the hairpin coils wound with two flat copper enameled wire conductors in parallel are connected in series and cross-transposed.

[0092] Fig.10 It is an expanded diagram of the stator winding in which the upper and lower conductors of the hairpin coils wound with two flat copper enameled wire conductors in parallel are connected in series and cross-transposed in the four parallel branches of the A2 phase winding.

[0093] Fig.11 It is a stator winding expansion diagram in which the upper and lower conductors of the hairpin coils wound with two flat copper enameled wire conductors in parallel in the four parallel branches of the B1 phase winding are connected in series and cross-transposed.

[0094] Fig.12 It is an expanded diagram of the stator winding in which the upper and lower conductors of the hairpin coils wound with two flat copper enameled wire conductors in parallel are connected in series and cross-transposed.

[0095] Fig.13 It is an expanded diagram of the stator winding in which the upper and lower conductors of the hairpin coils wound with two flat copper enameled wire conductors in parallel are connected in series and cross-transposed in the four parallel branches of the C1 phase winding.

[0096] Fig.14 It is an expanded diagram of the stator winding in which the upper and lower conductors of the hairpin coils wound with two flat copper enameled wire conductors in parallel are connected in series and cross-transposed in the four parallel branches of the C2 phase winding.

[0097] Fig.15 It is a schematic diagram of the position of the upper and lower conductors in the slots, the direct series connection and the cross-transposition connection of the eight hairpin coils wound in parallel by two flat copper enameled wire conductors in the A1 phase winding A1-1X1-1 parallel branch.

[0098] Fig.16 It is a schematic diagram of the position of the upper and lower conductors in the slots, the direct series connection and the cross-transposition connection of the 8 hairpin coils wound by two flat copper enameled wire conductors in parallel in the A1 phase winding A1-2X1-2 parallel branch.

[0099] Fig.17 It is a schematic diagram of the position of the upper and lower conductors in the slots, the direct series connection and the cross-transposition connection of the 8 hairpin coils wound by two flat copper enameled wire conductors in parallel in the A1 phase winding A1-3X1-3 parallel branch.

[0100] Fig.18 It is a schematic diagram of the position of the upper and lower conductors in the slots, the direct series connection and the cross-transposition connection of the 8 hairpin coils wound by two flat copper enameled wire conductors in parallel in the A1 phase winding A1-4X1-4 parallel branch.

[0101] Fig.19 It is an equivalent circuit diagram of the series connection and cross-transposition of the upper and lower conductors of 8 hairpin coils wound with two flat copper enameled wire conductors in the A1 phase winding A1-1X1-1 parallel branch.

[0102] Fig. 20 It is an equivalent circuit diagram of the series connection and cross-transposition of the upper and lower conductors of 8 hairpin coils wound with two flat copper enameled wire conductors in the A1 phase winding A1-2X1-2 parallel branch.

[0103] Fig.21 It is an equivalent circuit diagram of the series connection and cross-transposition of the upper and lower conductors of 8 hairpin coils wound with two flat copper enameled wire conductors in the A1 phase winding A1-3X1-3 parallel branch.

[0104] Fig. 22 It is an equivalent circuit diagram of the series connection and cross-transposition of the upper and lower conductors of 8 hairpin coils wound with two flat copper enameled wire conductors in the A1 phase winding A1-4X1-4 parallel branch.

[0105] Fig.23 It is an equivalent circuit diagram of the series connection and cross-transposition of the upper and lower conductors of eight hairpin coils wound with two flat copper enameled wire conductors in parallel in the A2 phase winding A2-1X2-1 parallel branch.

[0106] Fig.24 It is an equivalent circuit diagram of the series connection and cross-transposition of the upper and lower conductors of 8 hairpin coils wound with two flat copper enameled wire conductors in the A2 phase winding A2-2X2-2 parallel branch.

[0107] Fig.25It is an equivalent circuit diagram of the series connection and cross-transposition of the upper and lower conductors of eight hairpin coils wound with two flat copper enameled wire conductors in the A2-3X2-3 parallel branch of the A2 phase winding.

[0108] Fig.26 It is an equivalent circuit diagram of the series connection and cross-transposition of the upper and lower conductors of 8 hairpin coils wound with two flat copper enameled wire conductors in the A2-4X2-4 parallel branch of the A2 phase winding.

[0109] Fig. 27 It is an equivalent circuit diagram of the series connection and cross-transposition of the upper and lower conductors of eight hairpin coils wound with two flat copper enameled wire conductors in the parallel branch of the B1 phase winding B1-1Y1-1.

[0110] Fig.28 It is an equivalent circuit diagram of the series connection and cross-transposition of the upper and lower conductors of 8 hairpin coils wound with two flat copper enameled wire conductors in the B1 phase winding B1-2Y1-2 parallel branch.

[0111] Fig.29 It is the equivalent circuit diagram of the series connection and cross-transposition of the upper and lower conductors of 8 hairpin coils wound with two flat copper enameled wire conductors in the B1 phase winding B1-3Y1-3 parallel branch.

[0112] Fig.30 It is an equivalent circuit diagram of the series connection and cross-transposition of the upper and lower conductors of eight hairpin coils wound with two flat copper enameled wire conductors in the B1 phase winding B1-4Y1-4 parallel branch.

[0113] Fig.31 It is the equivalent circuit diagram of the series connection and cross-transposition of the upper and lower conductors of 8 hairpin coils wound with two flat copper enameled wire conductors in the parallel branch of B2 phase winding B2-1Y2-1.

[0114] Fig.32 It is an equivalent circuit diagram of the series connection and cross-transposition of the upper and lower conductors of eight hairpin coils wound with two flat copper enameled wire conductors in the parallel branch of the B2 phase winding B2-2Y2-2.

[0115] Fig.33 It is an equivalent circuit diagram of the series connection and cross-transposition of the upper and lower conductors of eight hairpin coils wound with two flat copper enameled wire conductors in the B2 phase winding B2-3Y2-3 parallel branch.

[0116] Fig.34 It is an equivalent circuit diagram of the series connection and cross-transposition of the upper and lower conductors of eight hairpin coils wound with two flat copper enameled wire conductors in the B2 phase winding B2-4Y2-4 parallel branch.

[0117] Fig.35It is an equivalent circuit diagram of the series connection and cross-transposition of the upper and lower conductors of 8 hairpin coils wound with two flat copper enameled wire conductors in parallel in the C1 phase winding C1-1Z1-1 parallel branch.

[0118] Fig.36 It is an equivalent circuit diagram of the series connection and cross-transposition of the upper and lower conductors of 8 hairpin coils wound with two flat copper enameled wire conductors in parallel in the C1 phase winding C1-2Z1-2 parallel branch.

[0119] Fig.37 It is an equivalent circuit diagram of the series connection and cross-transposition of the upper and lower conductors of 8 hairpin coils wound with two flat copper enameled wire conductors in parallel in the C1 phase winding C1-3Z1-3 parallel branch.

[0120] Fig.38 It is an equivalent circuit diagram of the series connection and cross-transposition of the upper and lower conductors of 8 hairpin coils wound with two flat copper enameled wire conductors in parallel in the C1 phase winding C1-4Z1-4 parallel branch.

[0121] Fig.39 It is an equivalent circuit diagram of the series connection and cross-transposition of the upper and lower conductors of eight hairpin coils wound with two flat copper enameled wire conductors in parallel in the C2 phase winding C2-1Z2-1 parallel branch.

[0122] Fig.40 It is an equivalent circuit diagram of the series connection and cross-transposition of the upper and lower conductors of 8 hairpin coils wound with two flat copper enameled wire conductors in the C2 phase winding C2-2Z2-2 parallel branch.

[0123] Fig.41 It is an equivalent circuit diagram of the series connection and cross-transposition of the upper and lower conductors of 8 hairpin coils wound with two flat copper enameled wire conductors in parallel in the C2 phase winding C2-3Z2-3 parallel branch.

[0124] Fig.42 It is an equivalent circuit diagram of the series connection and cross-transposition of the upper and lower conductors of eight hairpin coils wound with two flat copper enameled wire conductors in parallel in the C2 phase winding C2-4Z2-4 parallel branch.

[0125] Fig.43 It is an equivalent circuit of double three-phase Y-connection with a phase shift of 30°, each phase has 4 parallel branches and 8 Y-connected star points are not connected to each other. DETAILED DESCRIPTION

[0126] Combination Figure 1 to Figure 43 The proposed implementation of the present invention is described.

[0127] For a 48-slot, 4-pole, double three-phase Y-connected, 30° phase-shifted AC motor, such as a permanent magnet synchronous motor or an induction motor, the number of stator slots Z = 48 slots, the number of poles 2p = 4, and the number of phases m = 6. The number of slots represents the motor pole pitch τ = 12 slots, and the number of slots per pole per phase q = 2. For the fundamental wave of two pairs of poles, the slot pitch electrical angle α = 15°. Based on these data, it is possible to draw Figure 1 The star diagram of the electromotive force of the stator slot conductor of the 48-slot 4-pole double three-phase Y-connected 30° phase-shifted AC motor is shown. Figure 1 The phase separation results after the stator slot conductor electromotive force is star-shaped and phase-split according to 30° phase bands are also given.

[0128] After electromagnetic design, the stator winding is selected to have 4 parallel branches per phase, and the number of coil series turns of each parallel branch is 8. The coil is a wave winding with 1 turn. The coil adopts a hairpin coil, and the hairpin coil is an AC winding wound by two flat copper enameled wires of the lower conductor and the upper conductor. Then 8 hairpin coil edges need to be placed in each slot, and there are 16 flat copper enameled wire conductors in each slot. The cross-sectional diagram of the stator core and the conductor in the slot is shown as follows Figure 2 shown.

[0129] The schematic diagram of the layers of the coil sides of the 8 hairpin coils wound with two flat copper enameled wire conductors in each slot and the position relationship between the upper conductor and the lower conductor in each coil side is shown in the figure below. Figure 3 As shown. In each slot, the coil sides of the 1st, 2nd, 3rd, 4th, 5th, 6th, 7th and 8th layers of hairpin coils are inserted and embedded in sequence from the bottom of the slot to the slot opening. The flat copper enameled wire near the bottom of the slot among the two flat copper enameled wires wound in each layer of hairpin coils is recorded as the lower conductor, and the other flat copper enameled wire near the slot opening is recorded as the upper conductor. The two flat copper enameled wires wound in each hairpin coil are arranged in the slot with the upper conductor stacked on the lower conductor. The lower conductor and the upper conductor are insulated by the insulating paint film of the flat copper enameled wire itself, and no insulation treatment is required between the lower conductor and the upper conductor. Phase insulation is required between the 8 hairpin coils in each slot, and slot insulation is required between the slot and the hairpin coil.

[0130] When the slot numbers of the 48 slots are named counterclockwise from small to large, looking counterclockwise along the inner circumference of the stator core, the first slot encountered is the first slot in each positive phase band or negative phase band of the phase divided according to the phase division result, with a total of 24 slots. The slot numbers S of these 24 slots are all odd numbers. The two flat copper enameled wires are inserted into the Lth layer with an odd number of layers L in the slot with an odd number of slot numbers S and wound around the head end coil side of the hairpin coil. The head ends of the lower conductor and the upper conductor of the head end coil side of these hairpin coils are respectively recorded as and And the first span of these coils is y 1，1 =15 slots, y1，1 The slot number is greater than the motor pole pitch τ = 12 slots, and the tail coil sides of these coils are all located at the slot number (S+y 1，1 ), the layer number (L+1) is an even number, these are in the slot number (S+y 1，1 The tail ends of the lower conductor and the upper conductor of the (L+1)th layer of the hairpin coil are respectively marked as and When the slot number (S+y 1，1 )>48, then the corresponding slot number (S+y 1，1 ), corrected to slot number (S+y 1，1 -48);

[0131] When the slot numbers of the 48 slots are named counterclockwise from small to large, looking counterclockwise on the circumference of the stator core, the first slots encountered are the second slots in each positive phase band or negative phase band of the phase divided according to the phase division result, with a total of 24 slots. The slot numbers S of these 24 slots are all even numbers. The two flat copper enameled wires are inserted into the Lth layer with an odd number of layers L in the slots with even numbers S and are wound around the coil side of the head end of the hairpin coil. The head ends of the lower conductor and the upper conductor of the head end of the coil side of the hairpin coil are respectively recorded as and And the first span of these coils is y 1，2 =13 slots, y 1，2 The slot number of the tail coil side of these coils is (S+y 1，2 ), the layer number (L+1) is an even number, these are in the slot number (S+y 1，2 The tail ends of the lower conductor and the upper conductor of the (L+1)th layer of the hairpin coil are respectively marked as and When the slot number (S+y 1，2 )>48, then the corresponding slot number (S+y 1，2 ), corrected to slot number (S+y 1，2 -48);

[0132] Therefore, the first span length of the hairpin coil at the head end coil side in the odd slot and odd layer is y 1，1 = 15 slots, the first end coil side is in the even slots and odd layers of the hairpin coil first span length y 1，2= 13 slots, so that the non-welded ends of the two hairpin coils in the adjacent two slots in each positive phase band or negative phase band of the same phase divided according to the phase division result can be concentrically inlaid, which is convenient for spatial arrangement and simple in manufacturing process. In addition, the ends of most hairpin coils are only bent and twisted without cross-transposition. Taking the two sides of the lower conductor of the hairpin coil as an example, the "slot numbers" and related "names and symbols" of the two slots where the two sides of the lower conductor of the hairpin coil are located in the stator winding expansion diagram are shown as follows: Figure 4 shown. Figure 4 In the figure, the two sides of the lower conductor of the hairpin coil are separated by two "slot number" numbers in the middle; the upper end is connected to the lower conductors of the two coil sides of the hairpin coil by a "∧"-shaped "solid line", which means that the end of the coil conductor is already formed when the hairpin coil is made; the lower end is respectively connected to the lower conductors of the left and right coil sides of the hairpin coil, and the "dotted lines" are twisted to the left and right respectively, which means that after the hairpin coil is inserted into the corresponding positions of the two slots, the ends of the coil conductors on the left and right sides need to be twisted to the left and right respectively, so as to be connected in series with the two parallel-wound conductors of the front and rear hairpin coils that need to be connected in series through welding, or serve as the head and tail lead-out ends of the parallel branch of the phase winding.

[0133] Taking the two sides of the lower conductor of the hairpin coil as an example, the "equivalent circuit" and "name symbol" diagram of the two sides of the lower conductor of the hairpin coil in the equivalent circuit diagram of the phase winding parallel branch are as follows: Figure 5 shown.

[0134] and Figure 4 and Figure 5 Correspondingly, taking the two sides of the upper conductor of the hairpin coil as an example, we get Figure 6 and Figure 7 .

[0135] A1, B1, and C1 form a three-phase Y-connected symmetrical winding, and A2, B2, and C2 form another three-phase Y-connected symmetrical winding. The phase electromotive force between the fundamental waves of the two three-phase Y-connected symmetrical windings A1 and A2, B1 and B2, and C1 and C2 phases differ by 30 degrees electrical angle; the number of slots per pole and per phase is 2, and each phase has 4 parallel branches. The A1 phase winding is composed of 4 parallel branches, namely A1-1X1-1, A1-2X1-2, A1-3X1-3 and A1-4X1-4; the A2 phase winding is composed of 4 parallel branches, namely A2-1X2-1, A2-2X2-2, A2-3X2-3 and A2-4X2-4; the B1 phase winding is composed of 4 parallel branches, namely B1-1Y1-1, B1-2Y1-2, B1-3Y1-3 and B1-4Y1-4; The B2 phase winding is composed of four parallel branches, namely B2-1Y2-1, B2-2Y2-2, B2-3Y2-3 and B2-4Y2-4; the C1 phase winding is composed of four parallel branches, namely C1-1Z1-1, C1-2Z1-2, C1-3Z1-3 and C1-4Z1-4; the C2 phase winding is composed of four parallel branches, namely C2-1Z2-1, C2-2Z2-2, C2-3Z2-3 and C2-4Z2-4.

[0136] When connecting the phase winding parallel branches, the head ends of the 4 parallel branches of each phase winding are connected to the head ends of the 4 hairpin coils, and the coil sides are all at the head ends of the 4 slot bottoms in the positive phase band of each phase; the tail ends of the 4 parallel branches of each phase winding are connected to the head ends of the 4 hairpin coils, and the coil sides are all at the head ends of the 4 slot bottoms in the negative phase band of each phase.

[0137] Reference Figure 1 The star diagram of the slot electromotive force of the 48-slot 4-pole double three-phase Y-connected phase-shifted 30° AC motor and its phase separation and phase separation results according to the 30° phase band can be drawn to draw the stator six-phase winding expansion diagram. In order to clearly and intuitively show the connection rules of the four parallel branches of each phase, the following diagrams are drawn respectively: Figures 9 to 14 The stator winding expansion diagram shows that the upper and lower conductors of the hairpin coils wound with two flat copper enameled wire conductors in parallel in the four parallel branches of each phase winding are connected in series and cross-transposed.

[0138] The upper and lower conductors of the eight hairpin coils wound with two flat copper enameled wire conductors in parallel in the four parallel branches of the A1 phase winding are shown in the following figure: Figure 15 to Figure 18 As shown. The dotted lines between the coil ends in the figure It represents that the front and rear hairpin coil conductors that need to be connected in series are connected together by welding. The upper and lower conductors of the hairpin coils wound by two flat copper enameled wire conductors in parallel in the 4 parallel branches of the remaining 5 phase windings are similar to these 4 figures in terms of the position of the upper conductor and the lower conductor in the slot, the direct series connection and the cross-transposition connection schematic diagram, and are not drawn one by one.

[0139] "∧" indicates the connection of the end conductor of a hairpin coil where the conductor at the head end coil side is connected to the conductor at the tail end coil side; "=" indicates that the lower conductor at the tail end coil side of the first hairpin coil of the first four series-connected hairpin coils and the last four series-connected hairpin coils in each parallel branch is connected with the lower conductor at the head end coil side of the last hairpin coil by welding, and the upper conductor at the tail end coil side of the first hairpin coil is connected with the upper conductor at the head end coil side of the last hairpin coil by welding, that is, "=" indicates that "the front and rear hairpin coil sides are connected". The upper and lower conductors do not need to be transposed when they are connected by welding”; “×” is used to indicate that the lower conductor at the tail coil side of the last hairpin coil among the first four series-connected hairpin coils in each parallel branch is connected with the upper conductor at the head coil side of the last hairpin coil among the last four series-connected hairpin coils in the back by welding, and the upper conductor at the tail coil side of the previous hairpin coil is connected with the lower conductor at the head coil side of the next hairpin coil by welding, that is, “×” is used to indicate that the upper and lower conductors at the sides of the front and rear hairpin coils need to be cross-transposed when they are connected by welding.

[0140] The equivalent circuit diagrams of the upper and lower conductors of the eight hairpin coils wound with two flat copper enameled wire conductors in each parallel branch of each phase are connected in series and their cross-transposition are shown as follows: Figure 19 to Figure 42 shown.

[0141] The connection between the upper conductor and the lower conductor between the coil sides of the hairpin winding conductor of each parallel branch of each phase is:

[0142] The connection sequence of the two parallel-wound conductor coils in the A1-1X1-1 parallel branch of the A1 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0144] The connection sequence of the two parallel-wound conductor coils in the A1-2X1-2 parallel branch of the A1 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0147] The connection sequence of the two parallel-wound conductor coils in the A1-3X1-3 parallel branch of the A1 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0150] The connection sequence of the two parallel-wound conductor coils in the A1-4X1-4 parallel branch of the A1 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0153] The connection sequence of the two parallel-wound conductor coils in the A2-1X2-1 parallel branch of the A2 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0156] The connection sequence of the two parallel-wound conductor coils in the A2-2X2-2 parallel branch of the A2 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0159] The connection sequence of the two parallel-wound conductor coils in the A2-3X2-3 parallel branch of the A2 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0162] The connection sequence of the two parallel-wound conductor coils in the A2-4X2-4 parallel branch of the A2 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0165] The connection sequence of the two parallel-wound conductor coils in the B1-1Y-1 branch of the B1 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0167] The connection sequence of the two parallel conductor coils in the B1-2Y1-2 parallel branch of the B1 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0170] The connection sequence of the two parallel conductor coils in the B1-3Y1-3 parallel branch of the B1 phase winding is: the first line, the first end end; Article 2, beginning Tail end.

[0173] The connection sequence of the two parallel-wound conductor coils in the B1-4Y1-4 parallel branch of the B1 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0176] The connection sequence of the two parallel conductor coils in the B2-1Y2-1 parallel branch of the B2 phase winding is: the first line, the first end end; Article 2, beginning Tail end.

[0179] The connection sequence of the two parallel-wound conductor coils in the B2-2Y2-2 parallel branch of the B2 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0182] The connection sequence of the two parallel-wound conductor coils in the B2-3Y2-3 parallel branch of the B2 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0185] The connection sequence of the two parallel conductor coils in the B2-4Y2-4 parallel branch of the B2 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0188] The connection sequence of the two parallel-wound conductor coils in the C1-1Z-1 branch of the C1 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0190] The connection sequence of the two parallel-wound conductor coils in the C1-2Z1-2 parallel branch of the C1 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0193] The connection sequence of the two parallel-wound conductor coils in the C1-3Z1-3 parallel branch of the C1 phase winding is: the first line, the first end end; Article 2, beginning Tail end.

[0196] The connection sequence of the two parallel conductor coils in the C1-4Z1-4 parallel branch of the C1 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0199] The connection sequence of the two parallel-wound conductor coils in the C2-1Z2-1 parallel branch of the C2 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0201] The connection sequence of the two parallel conductor coils in the C2-2Z2-2 parallel branch of the C2 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0203] The connection sequence of the two parallel-wound conductor coils in the C2-3Z2-3 parallel branch of the C2 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0205] The connection sequence of the two parallel conductor coils in the C2-4Z2-4 parallel branch of the C2 phase winding is: the first line, the first end end; Article 2, beginning tail end;

[0207] Finally, the parallel branches of each phase are connected in parallel to form a complete dual three-phase AC winding, X1-1, Y1-1 and Z1-1 are connected to form a Y-shaped star point N1-1; X1-2, Y1-2 and Z1-2 are connected to form a Y-shaped star point N1-2; X1-3, Y1-3 and Z1-3 are connected to form a Y-shaped star point N1-3; X1-4, Y1-4 and Z1-4 are connected to form a Y-shaped star point N1-4; N1-1, N1-2, N1-3 and N1-4 are not connected to each other. X2-1, Y2-1 and Z2-1 are connected to form a Y-shaped star point N2-1; X2-2, Y2-2 and Z2-2 are connected to form a Y-shaped star point N2-2; X2-3, Y2-3 and Z2-3 are connected to form a Y-shaped star point N2-3; X2-4, Y2-4 and Z2-4 are connected to form a Y-shaped star point N2-4; N2-1, N2-2, N2-3 and N2-4 are not connected to each other. A1-1, A1-2, A1-3 and A1-4 are connected to form the input end of the A1 phase winding; B1-1, B1-2, B1-3 and B1-4 are connected to form the input end of the B1 phase winding; C1-1, C1-2, C1-3 and C1-4 are connected to form the input end of the C1 phase winding; A1, B1 and C1 form a Y-connected three-phase winding with 4 parallel branches and 4 star points that are not connected to each other; A2-1, A2-2, A2-3 and A2-4 are connected together to form the input end of the A2 phase winding; B2-1, B2-2, B2-3 and B2-4 are connected together to form the input end of the B2 phase winding; C2-1, C2-2, C2-3 and C2-4 are connected together to form the input end of the C2 phase winding; A2, B2 and C2 constitute a Y-connected three-phase winding with 4 parallel branches and 4 star points that are not connected to each other.

Claims

1. A method for cross-transposition of AC windings with two flat copper enameled wires wound around a hairpin coil, characterized in that: This method is applicable to 48-slot 4-pole double three-phase Y-connection with a phase shift of 30°, 2 slots per pole per phase, 4 parallel branches per phase, 8 turns of coil series connection in each parallel branch, and the hairpin coil is an AC winding composed of two flat copper enameled wires and a wave winding; The two flat copper enameled wires wound in each hairpin coil are arranged in the slot with the lower conductor stacked on the upper conductor, and no insulation treatment is required between the lower conductor and the upper conductor; each hairpin coil is a wave winding coil with one turn and a first span of a long distance; in order to simplify the production and embedding process of the hairpin coil, the end of each hairpin coil wound by two flat copper enameled wires is only bent and twisted, and no position change is performed; Each slot has 8 layers of hairpin coils wound with two flat copper enameled wires. There are 384 hairpin coils wound with two flat copper enameled wires in the 48 slots on the stator core, for a total of 192 hairpin coils. When the slot numbers of the 48 slots are named counterclockwise from small to large, looking counterclockwise along the inner circumference of the stator core, the first slot encountered is the first slot in each positive phase band or negative phase band of the phase divided according to the phase division result, a total of 24 slots, the slot numbers S of these 24 slots are all odd numbers, and the two flat copper enameled wires are inserted into the Lth layer with an odd number of layers L in the slot with an odd number of slot numbers S and wound around the coil side of the head end of the hairpin coil. The head ends of the lower conductor and the upper conductor of the head end of the coil side of the hairpin coil are respectively recorded as and And the first span of these coils is y 1，1 =15 slots, y 1，1 The slot number is greater than the motor pole pitch τ = 12 slots. The tail coil sides of these coils are all located at slot number (S+y 1，1 ), the layer number (L+1) is an even number, these are in the slot number (S+y 1，1 The tail ends of the lower conductor and the upper conductor of the (L+1)th layer of the hairpin coil are respectively marked as and When the slot number (S+y 1，1 )>48, the corresponding slot number (S+y 1，1 ) is corrected to slot number (S+y 1，1 -48); When the slot numbers of the 48 slots are named counterclockwise from small to large, looking counterclockwise on the circumference of the stator core, the first slot encountered is the second slot in each positive phase band or negative phase band of the phase divided according to the phase division result, for a total of 24 slots. The slot numbers S of these 24 slots are all even numbers. The two flat copper enameled wires are inserted into the Lth layer with an odd number of layers L in the slots with even numbers S and are wound around the coil side of the head end of the hairpin coil. The head ends of the lower conductor and the upper conductor of the coil side of the head end of the hairpin coil are respectively recorded as and And the first span of these coils is y 1，2 =13 slots, y 1，2 The slot number of the tail coil side of these coils is (S+y 1，2 ), the layer number (L+1) is an even number, these are in the slot number (S+y 1，2 The tail ends of the lower conductor and the upper conductor of the (L+1)th layer of the hairpin coil are respectively marked as and When the slot number (S+y 1，2 )>48, the corresponding slot number (S+y 1，2 ) is corrected to slot number (S+y 1，2 -48); In each slot, the coil sides of the 1st, 2nd, 3rd, 4th, 5th, 6th, 7th and 8th layers of hairpin coils are inserted in sequence from the bottom of the slot to the slot mouth. Phase insulation needs to be done between the coil sides of each layer, and slot insulation needs to be done between the slots and the coil sides. A1, B1, C1 form a three-phase Y-connected symmetrical winding, and A2, B2, C2 form another three-phase Y-connected symmetrical winding. The phase difference between the fundamental electromotive force of phase A1 and phase A2, phase B1 and phase B2, and phase C1 and phase C2 of the two three-phase Y-connected symmetrical windings is 30° electrical angle; the number of slots per pole and phase is 2, and each phase has 4 parallel branches; among them, the A1 phase winding is composed of 4 parallel branches of A1-1X1-1, A1-2X1-2, A1-3X1-3 and A1-4X1-4; the A2 phase winding is composed of A2-1X2-1, A2-2X2-2, A2-3X2-3 and A2-4X2 -44 parallel branches; B1 phase winding is composed of B1-1Y1-1, B1-2Y1-2, B1-3Y1-3 and B1-4Y1-44 parallel branches; B2 phase winding is composed of B2-1Y2-1, B2-2Y2-2, B2-3Y2-3 and B2-4Y2-44 parallel branches; C1 phase winding is composed of C1-1Z1-1, C1-2Z1-2, C1-3Z1-3 and C1-4Z1-44 parallel branches; C2 phase winding is composed of C2-1Z2-1, C2-2Z2-2, C2-3Z2-3 and C2-4Z2-44 parallel branches; The number of series turns of the coils of each parallel branch of each phase is 8 turns, that is, 8 hairpin coils are connected in series in each parallel branch; when the front 4 hairpin coils are connected in series and the rear 4 hairpin coils are connected in series, the upper conductor and the lower conductor are not transposed, and the upper conductors and the lower conductors of the two coil sides of the tail end and the head end of the front and rear hairpin coils are connected together by welding one by one, and the second span is y2=10 slots, and each welding point is well insulated; the head end of each parallel branch of each phase is the head end of the head end coil side of the first hairpin coil among the front 4 hairpin coils connected in series, and the head end coil side of the first hairpin coil is at the bottom of the slot numbered S - the first layer; When the first span of the first hairpin coil of each parallel branch of each phase is y 1，1 = 15 slots, the tail coil side of the first hairpin coil of this phase is at the slot number (S+y 1，1 ) in the second layer of the slot, the tail coil side of the first hairpin coil and the head coil side of the second hairpin coil are connected by a conductor without transposition, and the head and tail coil sides of the second hairpin coil are respectively in the slot number (S+y 1，1 +y2) slot and the slot number is (S+y 1，1 +y2+y 1，2 ) in the 4th layer of the slot, the tail coil side of the 2nd hairpin coil is connected with the head coil side of the 3rd hairpin coil by winding the conductor without transposition, the head and tail coil sides of the 3rd hairpin coil are in the 5th layer of the slot with slot number S and the slot number (S+y 1，1 ) in the 6th layer of the slot, the tail end coil side of the 3rd hairpin coil is connected with the head end coil side of the 4th hairpin coil by winding the conductor without transposition, and the head end and tail end of the coil side of the 4th hairpin coil are respectively in the slot number (S+y 1，1 +y2) slot and the slot number is (S+y 1，1 +y2+y 1，2 ) in the 8th layer of the slot, then, the tail end of the first 4 series coils - the tail end coil side of the 4th hairpin coil and the head end of the last 4 series coils - the tail end coil side of the 5th hairpin coil are cross-transposed and connected, that is, the upper and lower conductors of the two flat copper enameled wires are cross-transposed and welded in series to weaken the circulating current between the two conductors when the two flat copper enameled wires in the parallel branch of the phase winding are wound in parallel, that is, the slot number (S+y 1，1 +y2+y 1，2 ) in the slot with the 8th layer of the 4th hairpin coil at the tail end of the coil and the conductor in the slot with the number (S+y 1，1 +y2+y 1，2 -y 3，1 ) in the slot of the 8th layer, the lower conductor of the tail coil side of the 5th hairpin coil is welded and connected in series, and the lower conductor of the tail coil side of the 4th hairpin coil and the upper conductor of the tail coil side of the 5th hairpin coil are welded and connected in series, so as to realize the cross-transposition of the upper and lower conductors and the lower and upper conductors in series of the front 4 hairpin coils and the rear 4 hairpin coils. The third span slot y between the front and rear coil sides during the cross-transposition 3，1 =τ-1=11, the cross-transposed coil sides are all in the 8th layer of the slot; when the following 4 hairpin coils are connected in series, the tail end coil side of the 5th hairpin coil is in the slot number (S+y 1，1 +y2+y 1，2 -y 3，1 ) in the slot of the 8th layer, the first end coil side of the 5th hairpin coil is in the slot number (S+y2+y 1，2 -y 3，1 ) in the 7th layer of the slot, the first end coil side of the 5th hairpin coil and the tail end coil side of the 6th hairpin coil are connected by conductors without transposition, and the tail end coil side of the 6th hairpin coil is in the slot number (S+y 1，2 -y 3，1 ) slot, the sixth layer, the first end coil side of the sixth hairpin coil is in the slot number (Sy 3，1 ) in the fifth layer of the slot, the first coil side of the sixth hairpin coil and the tail coil side of the seventh hairpin coil are connected by a conductor without transposition, and the tail coil side of the seventh hairpin coil is in the slot number (S+y 1，1 +y2+y 1，2 -y 3，1 ) in the slot of the 4th layer, the first end coil side of the 7th hairpin coil is located at the slot number (S+y2+y 1，2 -y 3，1 ) in the third layer of the slot, the first end coil side of the 7th hairpin coil and the tail end coil side of the 8th hairpin coil are connected by conductors without transposition, and the tail end coil side of the 8th hairpin coil is in the slot number (S+y 1，2 -y 3，1 ) slot, the 2nd layer, the 8th hairpin coil head coil side is in the slot number (Sy 3，1 ) in the first layer of the slot, the head end of the head end coil side of the 8th hairpin coil is also the tail end of the parallel branch of this phase winding; When the first span of the first hairpin coil of each parallel branch of each phase is y 1，2 = 13 slots, the tail coil side of the first hairpin coil of this phase is at the slot number (S+y 1，2 ) in the second layer of the slot, the tail coil side of the first hairpin coil and the head coil side of the second hairpin coil are connected by a conductor without transposition, and the head and tail coil sides of the second hairpin coil are respectively in the slot number (S+y 1，2 +y2) slot and the slot number is (S+y 1，2 +y2+y 1，1 ) in the 4th layer of the slot, the tail coil side of the 2nd hairpin coil is connected with the head coil side of the 3rd hairpin coil by winding the conductor without transposition, the head and tail coil sides of the 3rd hairpin coil are in the 5th layer of the slot with slot number S and the slot number (S+y 1，2 ) in the 6th layer of the slot, the tail end coil side of the 3rd hairpin coil is connected with the head end coil side of the 4th hairpin coil by winding the conductor without transposition, and the head end and tail end of the coil side of the 4th hairpin coil are respectively in the slot number (S+y 1，2 +y2) slot and the slot number is (S+y 1，2 +y2+y 1，1 ) in the 8th layer of the slot, then, the tail end of the first 4 series coils - the tail end coil side of the 4th hairpin coil and the head end of the last 4 series coils - the tail end coil side of the 5th hairpin coil are cross-transposed and connected in parallel with the conductor, that is, it is necessary to cross-transpose and weld the upper and lower conductors wound by two flat copper enameled wires in parallel to connect in series, so as to weaken the circulating current between the two conductors when the two flat copper enameled wires in the parallel branch of the phase winding are wound in parallel, that is, to connect the conductor in the slot number (S+y 1，2 +y2+y 1，1 ) in the slot with the 8th layer of the 4th hairpin coil at the tail end of the coil and the conductor in the slot with the number (S+y 1，2 +y2+y 1，1 -y 3，2 ) in the slot of the 8th layer, the lower conductor of the tail coil side of the 5th hairpin coil is welded and connected in series, and the lower conductor of the tail coil side of the 4th hairpin coil and the upper conductor of the tail coil side of the 5th hairpin coil are welded and connected in series, so as to realize the cross-transposition of the upper and lower conductors and the lower and upper conductors in series of the front 4 hairpin coils and the rear 4 hairpin coils. The third span slot y during the cross-transposition 3，2 =τ+1=13, the coil sides of the cross-transposed coils are all in the 8th layer of the slot; when the following 4 hairpin coils are connected in series, the tail coil side of the 5th hairpin coil is in the slot number (S+y 1，2 +y2+y 1，1 -y 3，2 ) in the slot of the 8th layer, the first end coil side of the 5th hairpin coil is in the slot number (S+y2+y 1，1 -y 3，2 ) in the 7th layer of the slot, the first end coil side of the 5th hairpin coil and the tail end coil side of the 6th hairpin coil are connected by conductors without transposition, and the tail end coil side of the 6th hairpin coil is in the slot number (S+y 1，1 -y 3，2 ) slot, the first end coil side of the sixth layer and the sixth hairpin coil is in the slot number (Sy 3，2 ) in the fifth layer of the slot, the first coil side of the sixth hairpin coil and the tail coil side of the seventh hairpin coil are connected by a conductor without transposition, and the tail coil side of the seventh hairpin coil is in the slot number (S+y 1，2 +y2+y 1，1 -y 3，2 ) in the slot of the 4th layer, the first end coil side of the 7th hairpin coil is located at the slot number (S+y2+y 1，1 -y 3，2 ) in the third layer of the slot, the first end coil side of the 7th hairpin coil and the tail end coil side of the 8th hairpin coil are connected by conductors without transposition, and the tail end coil side of the 8th hairpin coil is in the slot number (S+y 1，1 -y 3，2 ) slot, the 2nd layer, the 8th hairpin coil head coil side is in the slot number (Sy 3，2 ) in the first layer of the slot, the head end of the head end coil side of the 8th hairpin coil is also the tail end of the parallel branch of this phase winding; "∧" indicates the connection of the end conductor of a hairpin coil where the conductor at the head end coil side is connected to the conductor at the tail end coil side; "=" indicates that the lower conductor at the tail end coil side of the first hairpin coil of the first four series-connected hairpin coils and the last four series-connected hairpin coils in each parallel branch is connected with the lower conductor at the head end coil side of the last hairpin coil by welding, and the upper conductor at the tail end coil side of the first hairpin coil is connected with the upper conductor at the head end coil side of the last hairpin coil by welding, that is, "=" indicates that the front and rear hairpin coil sides are connected. The upper and lower conductors do not need to be transposed when they are connected by welding”; "×" is used to indicate that the lower conductor at the tail coil side of the last hairpin coil among the first four series hairpin coils in each parallel branch is connected by welding with the upper conductor at the head coil side of the last hairpin coil among the last four series hairpin coils, and the upper conductor at the tail coil side of the first hairpin coil is connected by welding with the lower conductor at the head coil side of the last hairpin coil, that is, "×" is used to indicate that the upper and lower conductors at the sides of the front and rear hairpin coils need to be cross-transposed when they are connected by welding; The connection between the upper conductor and the lower conductor between the conductor coil sides of each parallel branch hairpin winding of each phase is: The connection sequence of the two parallel-wound conductor coils in the A1-1X1-1 parallel branch of the A1 phase winding is: the first line, the first end end; Article 2, beginning tail end; The connection sequence of the two parallel-wound conductor coils in the A1-2X1-2 parallel branch of the A1 phase winding is: the first line, the first end end; Article 2, beginning tail end; The connection sequence of the two parallel-wound conductor coils in the A1-3X1-3 parallel branch of the A1 phase winding is: the first line, the first end end; Article 2, beginning tail end; The connection sequence of the two parallel-wound conductor coils in the A1-4X1-4 parallel branch of the A1 phase winding is: the first line, the first end end; Article 2, beginning tail end; The connection sequence of the two parallel-wound conductor coils in the A2-1X2-1 parallel branch of the A2 phase winding is: the first line, the first end end; Article 2, beginning tail end; The connection sequence of the two parallel-wound conductor coils in the A2-2X2-2 parallel branch of the A2 phase winding is: the first line, the first end end; Article 2, beginning tail end; The connection sequence of the two parallel-wound conductor coils in the A2-3X2-3 parallel branch of the A2 phase winding is: the first line, the first end end; Article 2, beginning tail end; The connection sequence of the two parallel-wound conductor coils in the A2-4X2-4 parallel branch of the A2 phase winding is: the first line, the first end end; Article 2, beginning tail end; The connection sequence of the two parallel conductor coils in the B1-1Y-1 branch of the B1 phase winding is: the first line, the head end B1-2 end; Article 2, beginning tail end; The connection sequence of the two parallel conductor coils in the B1-2Y1-2 parallel branch of the B1 phase winding is: the first line, the first end end; Article 2, beginning tail end; The connection sequence of the two parallel conductor coils in the B1-3Y1-3 parallel branch of the B1 phase winding is: the first line, the first end end; Article 2, beginning tail end; The connection sequence of the two parallel-wound conductor coils in the B1-4Y1-4 parallel branch of the B1 phase winding is: the first line, the first end end; Article 2, beginning tail end; The connection sequence of the two parallel conductor coils in the B2-1Y2-1 parallel branch of the B2 phase winding is: the first line, the first end end; Article 2, beginning tail end; The connection sequence of the two parallel-wound conductor coils in the B2-2Y2-2 parallel branch of the B2 phase winding is: the first line, the first end end; Article 2, beginning tail end; The connection sequence of the two parallel-wound conductor coils in the B2-3Y2-3 parallel branch of the B2 phase winding is: the first line, the first end end; Article 2, beginning tail end; The connection sequence of the two parallel conductor coils in the B2-4Y2-4 parallel branch of the B2 phase winding is: the first line, the first end end; Article 2, beginning tail end; The connection sequence of the two parallel-wound conductor coils in the C1-1Z-1 branch of the C1 phase winding is: the first line, the first end end; Article 2, beginning tail end; The connection sequence of the two parallel-wound conductor coils in the C1-2Z1-2 parallel branch of the C1 phase winding is: the first line, the first end end; Article 2, beginning tail end; The connection sequence of the two parallel-wound conductor coils in the C1-3Z1-3 parallel branch of the C1 phase winding is: the first line, the first end end; Article 2, beginning tail end; The connection sequence of the two parallel conductor coils in the C1-4Z1-4 parallel branch of the C1 phase winding is: the first line, the first end end; Article 2, beginning tail end; The connection sequence of the two parallel-wound conductor coils in the C2-1Z2-1 parallel branch of the C2 phase winding is: the first line, the first end end; Article 2, beginning tail end; The connection sequence of the two parallel conductor coils in the C2-2Z2-2 parallel branch of the C2 phase winding is: the first line, the first end end; Article 2, beginning tail end; The connection sequence of the two parallel-wound conductor coils in the C2-3Z2-3 parallel branch of the C2 phase winding is: the first line, the first end end; Article 2, beginning tail end; The connection sequence of the two parallel conductor coils in the C2-4Z2-4 parallel branch of the C2 phase winding is: the first line, the first end end; Article 2, beginning tail end; Finally, the parallel branches of each phase are connected in parallel to form a complete double three-phase AC winding, connecting X1-1, Y1-1 and Z1-1 to form a Y-shaped star point N1-1; connecting X1-2, Y1-2 and Z1-2 to form a Y-shaped star point N1-2; connecting X1-3, Y1-3 and Z1-3 to form a Y-shaped star point N1-3; connecting X1-4, Y1-4 and Z1-4 to form a Y-shaped star point N1-4; N1- 1. N1-2, N1-3 and N1-4 are not connected to each other; connect X2-1, Y2-1 and Z2-1 to form a Y-shaped star point N2-1; connect X2-2, Y2-2 and Z2-2 to form a Y-shaped star point N2-2; connect X2-3, Y2-3 and Z2-3 to form a Y-shaped star point N2-3; connect X2-4, Y2-4 and Z2-4 to form a Y-shaped star point N2-4; N2-1, N2- 2. N2-3 and N2-4 are not connected to each other; A1-1, A1-2, A1-3 and A1-4 are connected to form the input end of the A1 phase winding; B1-1, B1-2, B1-3 and B1-4 are connected to form the input end of the B1 phase winding; C1-1, C1-2, C1-3 and C1-4 are connected to form the input end of the C1 phase winding; A1, B1 and C1 form 4 star points with 4 parallel branches and are not connected to each other A2-1, A2-2, A2-3 and A2-4 are connected to form the input end of the A2 phase winding; B2-1, B2-2, B2-3 and B2-4 are connected to form the input end of the B2 phase winding; C2-1, C2-2, C2-3 and C2-4 are connected to form the input end of the C2 phase winding; A2, B2 and C2 constitute a Y-connected three-phase winding with 4 parallel branches and 4 star points that are not connected to each other.

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