Background
With the development of new energy vehicles, the requirements on the permanent magnet synchronous motor for the vehicle are higher and higher. At present, motor stator windings with 4 layers, 6 layers and 8 layers of hairpin coils superposed are formed, each phase of most stator windings is one path or two branches are connected in parallel, and the power requirement of the permanent magnet synchronous motor for the automobile is difficult to meet, so that the improvement of the number of the branches of each phase of the stator windings becomes the inevitable choice for improving the power.
However, the circulation current exists among the branches connected in parallel, and particularly for the stator winding with the multilayer hairpin coils, the circulation current phenomenon is more remarkable. The existence of the circulation can increase the additional copper loss and the dragging loss of the motor, reduce the efficiency of the motor and seriously affect the rated parameters of the motor.
SUMMERY OF THE UTILITY MODEL
The utility model aims at providing a three-phase stator winding, every phase winding realizes with the parallelly connected mode of four branch roads, makes every groove phase position for rotor magnet steel the same in every branch road to make between all branch roads the hairpin coil in the same layer for the magnet steel position the same inslot, can eliminate the circulation between each branch road completely like this.
In order to achieve the above object, in a first aspect, the present invention provides a three-phase stator winding, including N layers of hairpin windings stacked in sequence, where N is greater than or equal to 4 and is an even number; each phase of stator winding comprises M parallel branches, and M is an integral multiple of 4; in each phase of stator winding, in each pair of parallel branches, the number of stator slots occupied by each hairpin coil in one branch is the same as that occupied by each hairpin coil in the other branch, the position of each stator slot where each hairpin coil in one branch is located relative to each magnetic steel on the rotor is the same as that of each stator slot where each hairpin coil in the other branch is located relative to each magnetic steel on the rotor, and the hairpin coils in each stator slot in one branch and the hairpin coils in each stator slot in the other branch are in the same layer; the welding end of the hairpin coil is on the same side as the wire outlet end of the winding.
Further, the number of stator slots is 48, the number of motor poles is 8, N is 8, and M is 4.
Further, the hairpin coils in each branch occupy all of the first to eighth layers.
Further, the hairpin coils in each leg occupy only once per layer under a pair of poles.
Furthermore, the hairpin coils in each branch are all different-layer overlines.
Further, the different-layer overline is an overline between adjacent layers, and the adjacent layers are any one of four layers of 1-2 layers, 3-4 layers, 5-6 layers and 7-8 layers.
Further, each branch of each phase stator winding comprises 16 complete hairpin coils, the span of each hairpin coil has both a full pitch and a short pitch, and the two spans occur alternately.
Further, the short distance is 4.
In a second aspect, the present invention provides a motor stator assembly, including the first aspect technical solution the three-phase stator winding.
In a third aspect, the present invention provides an electric machine, including the stator assembly of the electric machine according to the second aspect.
The utility model discloses an in all parallelly connected branches, have following tripartite characteristics simultaneously: the first aspect is that the number of the stator slots occupied by each hairpin coil is the same, the second aspect is that the position of the stator slot where each hairpin coil is located relative to each magnetic steel on the rotor is the same, and the third aspect is that the hairpin coils in each stator slot are in the same layer. According to the formula E-BLv sin theta and the waveform function E-E of the AC voltagemsin (wt + phi), branch having the three characteristics, B, L, v, theta, EmAnd phi is equal, the induced back electromotive force is equal, so that no potential difference exists between the branches, and circulating current cannot be generated between the branches.
Other features and advantages of the present invention will be described in detail in the detailed description which follows.
Detailed Description
The following detailed description of the embodiments of the present invention will be made with reference to the accompanying drawings. It is to be understood that the description of the embodiments herein is for purposes of illustration and explanation only and is not intended to limit the invention.
It should be noted that, in the following description of the technical solutions of the present invention, the orientation or positional relationship indicated by the directional terms is based on the orientation or positional relationship shown in the drawings, and is only for convenience of description and simplification of the present invention, and does not indicate or imply that the indicated device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention.
As shown in fig. 1, the utility model discloses an embodiment of three-phase stator winding for the stator slot number is 48, and the motor pole number is the three-phase PMSM of 8, has 4 pairs of rotor magnetic poles or rotor magnet steel promptly, and rotor magnet steel is rotor magnetic pole N, S shown in fig. 2 promptly. The pole pitch of the motor is 6, the pitch or span of the hairpin coil is equal to 6 for a full pitch, greater than 6 for a long pitch and less than 6 for a short pitch, and the hairpin winding has 8 layers, i.e., N is 8. In fig. 1, the middle row of numbers represents the number of the stator slots, and there are 48 stator slots, and eight lines from left to right in each slot correspond to the first, second, third, fourth, fifth, sixth, seventh, and eighth layers, respectively, where the first layer is the layer closest to the magnetic steel of the motor rotor, that is, the innermost layer relative to the axis of the motor.
As shown in fig. 1, each phase of stator winding includes 4 parallel branches, in each phase of stator winding, in each pair of parallel branches, the number of stator slots occupied by each hairpin coil in one branch is the same as the number of stator slots occupied by each hairpin coil in the other branch, the position of each stator slot in which each hairpin coil in one branch is located relative to each magnetic steel on the rotor is the same as the position of each stator slot in which each hairpin coil in the other branch is located relative to each magnetic steel on the rotor, and the hairpin coils in each stator slot in one branch are in the same layer as the hairpin coils in each stator slot in the other branch; the welding end of the hairpin coil is on the same side as the wire outlet end of the winding.
In this embodiment, taking phase B as an example, there are 4 parallel branches B1-B4, and each two parallel branches form a pair, so there are C (4, 2) ═ 6 pairs of parallel branches, which are B1 and B2, B1 and B3, B1 and B4, B2 and B3, B2 and B4, and B3 and B4, and there is no circulation between each pair of parallel branches.
Taking the branch B1 and the branch B3 as an example, as shown in fig. 2, under two opposite polarities, each hairpin coil in the branch B1 occupies 2 slot 1 layers, 2 slot 3 layers, 2 slot 5 layers, 2 slot 7 layers, 8 slot 2 layers, 8 slot 4 layers, 8 slot 6 layers, 8 slot 8 layers, 15 slot 1 layers, 15 slot 3 layers, 15 slot 5 layers, 15 slot 7 layers, 19 slot 2 layers, 19 slot 4 layers, 19 slot 6 layers, 19 slot 8 layers, and occupies 4 stator slots, and accordingly, each hairpin coil in the branch B3 occupies 2 slot 2 layers, 2 slot 4 layers, 2 slot 6 layers, 2 slot 8 layers, 9 slot 1 layers, 9 slot 3 layers, 9 slot 5 layers, 9 slot 7 layers, 13 slot 2 layers, 13 slot 4 layers, 13 slot 6 layers, 13 slot 8 layers, 20 slot 1 layers, 20 slot 3 layers, 20 slot 5 layers, 20 slot 7 layers, and 4 stator slots. The position of 2 slots occupied by the hairpin coils in the branch B1 relative to the rotor magnetic steel N is the same as the position of 20 slots occupied by the hairpin coils in the branch B3 relative to the rotor magnetic steel S, the hairpin coils of 2 slots in the branch B1 are respectively positioned at 1 layer, 3 layers, 5 layers and 7 layers, and the hairpin coils of 20 slots in the branch B3 are also respectively positioned at 1 layer, 3 layers, 5 layers and 7 layers, namely at the same layer; the position of 8 slots occupied by the hairpin coils in the branch B1 relative to the rotor magnetic steel S is the same as the position of 2 slots occupied by the hairpin coils in the branch B3 relative to the rotor magnetic steel N, the 8-slot hairpin coils in the branch B1 are respectively positioned at 2 layers, 4 layers, 6 layers and 8 layers, and the 2-slot hairpin coils in the branch B3 are also respectively positioned at 2 layers, 4 layers, 6 layers and 8 layers, namely at the same layer; the position of the 15 slots occupied by the hairpin coils in the branch B1 relative to the rotor magnetic steel N is the same as the position of the 9 slots occupied by the hairpin coils in the branch B3 relative to the rotor magnetic steel S, the 15 slots of the hairpin coils in the branch B1 are respectively positioned at 1 layer, 3 layers, 5 layers and 7 layers, and the 9 slots of the hairpin coils in the branch B3 are also respectively positioned at 1 layer, 3 layers, 5 layers and 7 layers, namely at the same layer; the positions of 19 slots occupied by the hairpin coils in branch B1 with respect to rotor magnetic steel S are the same as the positions of 13 slots occupied by the hairpin coils in branch B3 with respect to rotor magnetic steel N, the 19 slot hairpin coils in branch B1 are respectively located at 2, 4, 6 and 8 layers, and the 13 slot hairpin coils in branch B3 are also respectively located at 2, 4, 6 and 8 layers, i.e., at the same layer. Therefore, the branch B1 and the branch B3 have the following three characteristics that 1, the number of the stator slots occupied by the hairpin coils is the same, 2, the positions of the stator slots where the hairpin coils are located relative to the magnetic steels on the rotor are the same, and 3, the hairpin coils in the stator slots are in the same layer. Therefore, the back emf induced in branch B1 is equal to the back emf induced in branch B3, so that no potential difference exists between branch B1 and branch B3, and no circulating current is generated between branch B1 and branch B3.
Further, taking the branch B2 and the branch B4 as an example, as shown in fig. 2, under two opposite polarities, each hairpin coil in the branch B2 occupies 3 slot 1 layers, 3 slot 3 layers, 3 slot 5 layers, 3 slot 7 layers, 7 slot 2 layers, 7 slot 4 layers, 7 slot 6 layers, 7 slot 8 layers, 14 slot 1 layers, 14 slot 3 layers, 14 slot 5 layers, 14 slot 7 layers, 20 slot 2 layers, 20 slot 4 layers, 20 slot 6 layers, 20 slot 8 layers, and occupies 4 stator slots, and accordingly, each hairpin coil in the branch B4 occupies 1 slot 2 layers, 1 slot 4 layers, 1 slot 6 layers, 1 slot 8 layers, 8 slot 1 layers, 8 slot 3 layers, 8 slot 5 layers, 8 slot 7 layers, 14 slot 2 layers, 14 slot 4 layers, 14 slot 6 layers, 14 slot 8 layers, 21 slot 1 layers, 21 slot 3 layers, 21 slot 5 layers, 21 slot 7 layers, and 4 stator slots. The position of 3 slots occupied by the hairpin coils in the branch B2 relative to the rotor magnetic steel N is the same as the position of 21 slots occupied by the hairpin coils in the branch B4 relative to the rotor magnetic steel S, the hairpin coils of 3 slots in the branch B2 are respectively positioned at 1 layer, 3 layers, 5 layers and 7 layers, and the hairpin coils of 21 slots in the branch B4 are also respectively positioned at 1 layer, 3 layers, 5 layers and 7 layers, namely at the same layer; the position of 7 slots occupied by the hairpin coils in the branch B2 relative to the rotor magnetic steel S is the same as the position of 1 slot occupied by the hairpin coils in the branch B4 relative to the rotor magnetic steel N, the 7 slots of the hairpin coils in the branch B2 are respectively positioned at 2 layers, 4 layers, 6 layers and 8 layers, and the 1 slot of the hairpin coils in the branch B4 are also respectively positioned at 2 layers, 4 layers, 6 layers and 8 layers, namely at the same layer; the position of 14 slots occupied by the hairpin coils in the branch B2 relative to the rotor magnetic steel N is the same as the position of 8 slots occupied by the hairpin coils in the branch B4 relative to the rotor magnetic steel S, the 14 slots of the hairpin coils in the branch B2 are respectively positioned at 1 layer, 3 layers, 5 layers and 7 layers, and the 8 slots of the hairpin coils in the branch B4 are also respectively positioned at 1 layer, 3 layers, 5 layers and 7 layers, namely at the same layer; the positions of 20 slots occupied by the hairpin coils in branch B2 with respect to rotor magnetic steel S are the same as the positions of 14 slots occupied by the hairpin coils in branch B4 with respect to rotor magnetic steel N, the 20 slots of the hairpin coils in branch B2 are respectively located at 2, 4, 6 and 8 layers, and the 14 slots of the hairpin coils in branch B4 are also respectively located at 2, 4, 6 and 8 layers, i.e., at the same layer. Therefore, the branch B2 and the branch B4 have the following three characteristics that 1, the number of the stator slots occupied by the hairpin coils is the same, 2, the positions of the stator slots where the hairpin coils are located relative to the magnetic steels on the rotor are the same, and 3, the hairpin coils in the stator slots are in the same layer. Therefore, the back emf induced in branch B2 is equal to the back emf induced in branch B4, so that no potential difference exists between branch B2 and branch B4, and no circulating current is generated between branch B2 and branch B4.
Similarly, there is no circular current between other 4 pairs of branches.
As can be seen from fig. 2, the hairpin coils in the 4 parallel branches occupy all 8 layers under a pair of poles, and only once at each layer.
As can be seen from fig. 1, the winding paths of the 4 parallel branches in phase B are as follows:
branch B1:
2 groove 1 layer-8 groove 2 layer-15 groove 1 layer-19 groove 2 layer-26 groove 1 layer-32 groove 2 layer-39 groove 1 layer-43 groove 2 layer-2 groove 3 layer-8 groove 4 layer-15 groove 3 layer-19 groove 4 layer-26 groove 3 layer-32 groove 4 layer-39 groove 3 layer-43 groove 4 layer-2 groove 5 layer-8 groove 6 layer-15 groove 5 layer-19 groove 6 layer-26 groove 5 layer-32 groove 6 layer-39 groove 5 layer-43 groove 6 layer-2 groove 7 layer-8 groove 8 layer-15 groove 7 layer-19 groove 8 layer-26 groove 7 layer-32 groove 8 layer-39 groove 7 layer-43 groove 8 layer.
The outlet end of the 1-layer slot 2 at the starting end is a power supply end B1 of the winding and is used for externally connecting an alternating current power supply, and the outlet end of the 8-layer slot 43 at the ending end is a winding neutral point Y1. The branch circuit is provided with 16 complete hairpin coils, each hairpin coil is a different-layer overline between adjacent layers, and the adjacent layers are selected from four layers of 1-2 layers, 3-4 layers, 5-6 layers and 7-8 layers, namely, the adjacent layers are formed by every two layers in sequence from 1-8 layers, so that the branch circuit has strong regularity and the overline structure is simplified. It can also be seen that the hairpin coils in branch B1 occupy all of the first through eighth layers. In addition, the hairpin coil has two spans of a full pitch 6 and a short pitch 4, and the two spans alternately occur at intervals.
Branch B2:
3 grooves 1 layer-7 grooves 2 layer-14 grooves 1 layer-20 grooves 2 layer-27 grooves 1 layer-31 grooves 2 layer-38 grooves 1 layer-44 grooves 2 layer-3 grooves 3 layer-7 grooves 4 layer-14 grooves 3 layer-20 grooves 4 layer-27 grooves 3 layer-31 grooves 4 layer-38 grooves 3 layer-44 grooves 4 layer-3 grooves 5 layer-7 grooves 6 layer-14 grooves 5 layer-20 grooves 6 layer-27 grooves 5 layer-31 grooves 6 layer-38 grooves 5 layer-44 grooves 6 layer-3 grooves 7 layer-7 grooves 8 layer-14 grooves 7 layer-20 grooves 8 layer-27 grooves 7 layer-31 grooves 8 layer-38 grooves 7 layer-44 grooves 8 layer.
The outlet end of the 1-layer slot 3 of the starting end is a power supply end B2 of the winding and is used for externally connecting an alternating current power supply, and the outlet end of the 8-layer slot 44 of the ending end is a winding neutral point Y2. The branch circuit is provided with 16 complete hairpin coils, each hairpin coil is a different-layer overline between adjacent layers, and the adjacent layers are selected from four layers of 1-2 layers, 3-4 layers, 5-6 layers and 7-8 layers, namely, the adjacent layers are formed by every two layers in sequence from 1-8 layers, so that the branch circuit has strong regularity and the overline structure is simplified. It can also be seen that the hairpin coils in branch B2 occupy all of the first through eighth layers. In addition, the hairpin coil has two spans of a full pitch 6 and a short pitch 4, and the two spans alternately occur at intervals.
Branch B3:
2 groove 8 layers-44 groove 7 layers-37 groove 8 layers-33 groove 7 layers-26 groove 8 layers-20 groove 7 layers-13 groove 8 layers-9 groove 7 layers-2 groove 6 layers-44 groove 5 layers-37 groove 6 layers-33 groove 5 layers-26 groove 6 layers-20 groove 5 layers-13 groove 6 layers-9 groove 5 layers-2 groove 4 layers-44 groove 3 layers-37 groove 4 layers-33 groove 3 layers-26 groove 4 layers-20 groove 3 layers-13 groove 4 layers-9 groove 3 layers-2 groove 2 layers-44 groove 1 layers-37 groove 2 layers-33 groove 1 layers-26 groove 2 layers-20 groove 1 layers-13 groove 2 layers-9 groove 1 layers.
The outlet end of the starting end 2, the groove 8 layer is the power supply end B3 of the winding and is used for externally connecting an alternating current power supply, and the outlet end of the ending end 9, the groove 1 layer is the neutral point Y3 of the winding. The branch circuit is provided with 16 complete hairpin coils, each hairpin coil is a different-layer overline between adjacent layers, and the adjacent layers are selected from four layers of 1-2 layers, 3-4 layers, 5-6 layers and 7-8 layers, namely, the adjacent layers are formed by every two layers in sequence from 1-8 layers, so that the branch circuit has strong regularity and the overline structure is simplified. It can also be seen that the hairpin coils in branch B3 occupy all of the first through eighth layers. In addition, the hairpin coil has two spans of a full pitch 6 and a short pitch 4, and the two spans alternately occur at intervals.
Branch B4:
1 groove 8 layer-45 groove 7 layer-38 groove 8 layer-32 groove 7 layer-25 groove 8 layer-21 groove 7 layer-14 groove 8 layer-8 groove 7 layer-1 groove 6 layer-45 groove 5 layer-38 groove 6 layer-32 groove 5 layer-25 groove 6 layer-21 groove 5 layer-14 groove 6 layer-8 groove 5 layer-1 groove 4 layer-45 groove 3 layer-38 groove 4 layer-32 groove 3 layer-25 groove 4 layer-21 groove 3 layer-14 groove 4 layer-8 groove 3 layer-1 groove 2 layer-45 groove 1 layer-38 groove 2 layer-32 groove 1 layer-25 groove 2 layer-21 groove 1 layer-14 groove 2 layer-8 groove 1 layer.
The outlet end of the layer of the groove 8 at the start end 1 is a power supply end B4 of the winding and is used for externally connecting an alternating current power supply, and the outlet end of the layer of the groove 1 at the tail end 8 is a winding neutral point Y4. The branch circuit is provided with 16 complete hairpin coils, each hairpin coil is a different-layer overline between adjacent layers, and the adjacent layers are selected from four layers of 1-2 layers, 3-4 layers, 5-6 layers and 7-8 layers, namely, the adjacent layers are formed by every two layers in sequence from 1-8 layers, so that the branch circuit has strong regularity and the overline structure is simplified. It can also be seen that the hairpin coils in branch B4 occupy all of the first through eighth layers. In addition, the hairpin coil has two spans of a full pitch 6 and a short pitch 4, and the two spans alternately occur at intervals.
The above embodiment only takes phase B as an example, and 4 parallel branches of phase a and phase C have the same arrangement structure and the beneficial effect brought by the same arrangement structure with phase B, and are not described herein again.
Even if the hairpin coils of the same span are arranged, the sizes of the hairpin coils are different as long as the number of layers in the stator slots is different, so that the hairpin coils of the same span have various sizes. In each parallel branch, the hairpin coils of each span between the four adjacent layers, so that 8 sizes of hairpin coils are needed, and correspondingly 8 molds are needed to manufacture the 8 hairpin coils, while the stator winding of the existing structure usually has more than 10 hairpin coils, the types of the hairpin coils are reduced, and correspondingly, the required molds are also reduced, so that the production efficiency can be improved, and the cost can be reduced.
The utility model discloses motor stator assembly's embodiment for the stator slot number is 48, and the motor pole number is 8 three-phase permanent magnet synchronous motor, including any embodiment of above-mentioned three-phase stator winding, all beneficial effects that the technical scheme who has any embodiment of above-mentioned three-phase stator winding brought have at least.
The utility model discloses the embodiment of motor, this motor are that the number of poles is 8, and the stator slot number is 48 three-phase permanent magnet synchronous motor, including the embodiment of above-mentioned motor stator assembly in, have all beneficial effects that the technical scheme of the arbitrary embodiment of above-mentioned three-phase stator winding brought at least.
The preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited thereto. In the technical idea scope of the present invention, it is possible to provide the technical solution of the present invention with a plurality of simple modifications, including combining each specific technical feature in any suitable manner, and in order to avoid unnecessary repetition, the present invention does not provide additional description for various possible combinations. These simple variations and combinations should also be considered as disclosed in the present invention, all falling within the scope of protection of the present invention.