Stator assembly, electric machine and vehicle

Abstract

The application provides a kind of stator assembly, motor and vehicle, it is related to motor technical field, stator assembly includes stator core, three-phase stator winding wound on stator core and controller. Each phase stator winding includes a plurality of coil structures rotationally symmetrical about the axis of stator core, and the incoming and outgoing ends of coil structure are electrically connected with the controller. The controller is used to switch the series-parallel relationship of different coil structures in the same phase stator winding. And / or, the controller is used to switch the three-phase stator winding between star connection state and delta connection state. In this way, the average efficiency of the motor under all operating conditions is higher, and the energy consumption is lower.

Description

Technical Field

[0001] This application relates to the field of motor technology, and more particularly to a stator assembly, a motor, and a vehicle. Background Technology

[0002] Electric motors, as drive devices, are widely used in vehicles, industrial equipment, and other fields. With the increasing diversity of applications, motors often need to switch between different operating conditions, such as low-speed and high-speed operation. However, the average efficiency of motors across all operating conditions still needs improvement in related technologies. Summary of the Invention

[0003] In view of the above problems, embodiments of this application provide a stator assembly, a motor, and a vehicle, wherein the motor has a high average efficiency and low energy consumption across all operating conditions.

[0004] To achieve the above objectives, the embodiments of this application provide the following technical solutions:

[0005] In a first aspect, embodiments of this application provide a stator assembly, including a stator core, a three-phase stator winding wound around the stator core, and a controller;

[0006] Each phase stator winding includes multiple coil structures that are rotationally symmetrical about the axis of the stator core. The input and output ends of the coil structures are electrically connected to the controller.

[0007] The controller is used to switch the series-parallel connection relationship of different coil structures in the same phase stator winding; and / or, the controller is used to switch the three-phase stator winding between a star connection state and a delta connection state.

[0008] The stator assembly provided in this application allows for adjustment of motor parameters such as magnetomotive force (MTF), back EMF coefficient, and impedance parameters according to the motor's operating conditions by switching the wiring at the input and output terminals of the coil structure using a controller. This increases the motor's MMF at low speeds, resulting in greater output torque at the same current, thus reducing current demand and DC copper losses, leading to lower energy consumption and higher efficiency at low speeds. Conversely, it reduces the back EMF coefficient at high speeds, resulting in a lower back EMF at the same speed, thus reducing field weakening current demand, field weakening losses, and AC additional losses at high speeds, further resulting in lower energy consumption and higher efficiency at high speeds. This, in turn, helps to broaden the motor's efficient operating range, improve the average efficiency across all operating conditions, and reduce energy consumption.

[0009] By increasing the magnetomotive force of the motor when it is operating at low speed, the controller can also be prevented from operating in a small duty cycle range when the motor is operating at low speed, thus improving the controller's operating efficiency.

[0010] By increasing the motor's magnetomotive force (EMF) at low speeds and decreasing its back EMF coefficient at high speeds, the motor can meet the demand for high torque at low speeds while maintaining a low back EMF at high speeds, making it less likely to exceed bus voltage limits. A lower back EMF at high speeds reduces the need for field weakening current and simplifies field weakening, resulting in less field weakening loss and additional AC losses. This allows for increasing the motor's maximum speed to meet the demands of high-speed electric drives. Thus, a balance can be struck between high- and low-speed performance.

[0011] By switching the controller, the magnetomotive force, back EMF coefficient, impedance parameters and other parameters of the motor can be adjusted according to the motor's operating conditions. This allows the three-phase stator windings to adapt to a wider range of fluctuating bus voltages. It also allows for lower high-torque output current under low bus voltage, which helps reduce current stress on power devices and lower heat dissipation costs. The motor has good system adaptability.

[0012] Each phase stator winding comprises multiple coil structures that are rotationally symmetrical about the axis of the stator core. This ensures that the magnetic field distribution and potential balance are identical across all coil structures in each phase stator winding. The input and output terminals of the coil structures serve as switching points, allowing for seamless connection of the entire coil structure. This facilitates switching between different connection relationships at the input and output terminals of different coil structures, ensuring identical magnetic field distribution and potential balance across all branches of the same phase stator winding. It also minimizes the generation of circulating currents between branches, significantly reducing additional AC copper losses at high frequencies, improving motor efficiency during high-speed operation, and reducing the likelihood of localized overheating in the three-phase stator windings, thus extending the motor's lifespan.

[0013] In some embodiments, the stator core has a plurality of stator slots arranged circumferentially along the stator core, the coil structure corresponds to the plurality of stator slots, and the stator slots are divided into N slot layers along the radial direction of the stator core;

[0014] The coil structure includes multiple hairpin coils, which are wound around corresponding stator slots. The input end of the coil structure is led out from the hairpin coil located at the beginning of the coil structure, and the output end of the coil structure is led out from the hairpin coil located at the end of the coil structure.

[0015] The hairpin coil connects two adjacent slot layers across layers. The coil structure traverses N slot layers in different stator slots through the hairpin coil. The coil structure occupies at least one slot layer in each corresponding stator slot.

[0016] This allows for adjustments to parameters such as magnetomotive force, back EMF coefficient, and impedance parameters of the flat wire motor according to its operating conditions. This improves the average efficiency of the flat wire motor across all operating conditions, balances its high and low speed performance, enhances system adaptability, and increases the operating efficiency of the controller used to control the flat wire motor. Furthermore, it eliminates the potential phase difference caused by the different positions of different coil structures in the stator slots of the same phase stator winding. The input and output terminals of the coil structure serve as switching points, with the entire coil structure connected. This facilitates switching between different wiring relationships at the input and output terminals of different coil structures, eliminating the potential phase difference caused by the different positions of different branches of the same phase stator winding in the stator slots. It also reduces the likelihood of circulating currents between branches, decreases additional AC copper losses at high frequencies, improves motor efficiency at high speeds, and prevents localized overheating of the three-phase stator windings, thus extending the motor's lifespan. Additionally, the hairpin coils connecting adjacent slot layers across layers allow for a smaller size of each phase stator winding, contributing to a smaller overall size of the flat wire motor.

[0017] In some embodiments, the N slot layers are numbered sequentially from the first slot layer to the Nth slot layer, from the side closest to the axis of the stator core to the side furthest from the axis of the stator core.

[0018] One of the input and output terminals of the coil structure is led out from the first slot layer, and the other of the input and output terminals of the coil structure is led out from the Nth slot layer.

[0019] This allows multiple coil structures that make the same phase stator winding rotationally symmetrical about the axis of the stator core to traverse N slot layers in the corresponding different stator slots and occupy at least one slot layer in each corresponding stator slot. This makes it easier to prevent circulating currents from being generated between the branches of the same phase stator winding when switching the input and output terminals of different coil structures to various connection relationships.

[0020] In some embodiments, the number of poles of the stator core is 6m, and each pole of each phase stator winding corresponds to 3 stator slots, where m is a positive integer and N is an even number;

[0021] The stator winding of each phase has a partial coil structure of type I and a partial coil structure of type II.

[0022] The first type of coil structure starts from the first slot layer and alternately winds between two adjacent slot layers. After passing through each pole, it winds in a direction away from the axis of the stator core to the next adjacent slot layer, until it alternately winds through each pole between the (N-1)th slot layer and the Nth slot layer. The inlet of the first type of coil structure is led out from the first slot layer, and the outlet of the first type of coil structure is led out from the Nth slot layer.

[0023] The second type of coil structure starts from the Nth slot layer and alternately winds between two adjacent slot layers. After passing through each pole, it winds towards the axis of the stator core to the adjacent upper slot layer, until it alternately winds between the second slot layer and the first slot layer to pass through each pole. The input end of the second type of coil structure is led out from the Nth slot layer, and the output end of the second type of coil structure is led out from the first slot layer.

[0024] This allows multiple coil structures that make the same phase stator winding rotationally symmetrical about the axis of the stator core to traverse N slot layers in the corresponding different stator slots and occupy at least one slot layer in each corresponding stator slot. This makes it easier to prevent circulating currents from being generated between the branches of the same phase stator winding when switching the input and output terminals of different coil structures to various connection relationships.

[0025] In some embodiments, each coil structure includes three different pitch hairpin coils, namely a first hairpin coil, a second hairpin coil, and a third hairpin coil.

[0026] The first hairpin coil has a pitch of 8, the second hairpin coil has a pitch of 9, and the third hairpin coil has a pitch of 11.

[0027] In this way, multiple coil structures that allow the same phase stator winding to rotate symmetrically around the axis of the stator core can traverse N slot layers in corresponding different stator slots and occupy at least one slot layer in each corresponding stator slot. At the same time, fewer types of hairpin coils are required, which helps to save on manufacturing mold costs and increase production cycle time.

[0028] In some embodiments, each phase stator winding includes six coil structures, namely a first coil structure, a second coil structure, a third coil structure, a fourth coil structure, a fifth coil structure, and a sixth coil structure.

[0029] Among them, the first coil structure, the third coil structure, and the fifth coil structure are one of the first type of coil structure and the second type of coil structure, while the second coil structure, the fourth coil structure, and the sixth coil structure are the other of the first type of coil structure and the second type of coil structure.

[0030] This facilitates switching between various series and parallel connection methods for the coil structure of each phase stator winding, and makes it easier to prevent circulating currents from being generated between branches of the same phase stator winding when switching the input and output terminals of different coil structures to various connection relationships.

[0031] In some embodiments, the stator assembly has at least two of a first operating mode, a second operating mode, and a third operating mode, and the controller is capable of switching the stator assembly between at least two of the first operating mode, the second operating mode, and the third operating mode;

[0032] When the stator assembly is in the first working mode, the three-phase stator windings are in a star connection state, and the first coil structure, second coil structure, third coil structure, fourth coil structure, fifth coil structure and sixth coil structure of the same phase stator winding are connected in series in sequence;

[0033] When the stator assembly is in the second working mode, the three-phase stator windings are in a star connection state. The first coil structure, the second coil structure and the third coil structure of the same phase stator winding are connected in series to form the first branch. The fourth coil structure, the fifth coil structure and the sixth coil structure of the same phase stator winding are connected in series to form the second branch. The first branch and the second branch of the same phase stator winding are connected in parallel.

[0034] When the stator assembly is in the third operating mode, the three-phase stator windings are in a star connection state. The first coil structure and the second coil structure of the same phase stator winding are connected in series to form the third branch. The third coil structure and the fourth coil structure of the same phase stator winding are connected in series to form the fourth branch. The fifth coil structure and the sixth coil structure of the same phase stator winding are connected in series to form the fifth branch. The third, fourth and fifth branches of the same phase stator winding are connected in parallel.

[0035] In this way, the stator assembly can be switched between at least two of the first, second, and third operating modes by the controller to adjust the number of branches and turns of the same phase stator winding. This allows parameters such as the motor's magnetomotive force, back EMF coefficient, and impedance parameters to be adjusted according to the motor's operating conditions. This improves the average efficiency of the flat wire motor under all operating conditions, balances its high and low speed performance, enhances its system adaptability, and increases the operating efficiency of the controller used to control the flat wire motor. When the stator assembly is in the first, second, and third operating modes, circulating currents are less likely to occur between the branches of each phase stator winding.

[0036] In some embodiments, N≤6, the coil structure occupies one slot layer in each corresponding stator slot.

[0037] This allows multiple coil structures that are rotationally symmetrical about the axis of the stator core in the same phase stator winding to traverse N slot layers in the corresponding different stator slots when the number of stator slot layers is small. It also makes it easier to prevent circulating currents from being generated between branches of the same phase stator winding when switching between various wiring relationships at the input and output ends of different coil structures.

[0038] In some embodiments, N > 6, the coil structure occupies at least two slot layers in the corresponding at least part of the stator slot, and there is a gap of 5 slot layers between adjacent slot layers in the multiple slot layers occupied by the coil structure in the same stator slot.

[0039] This allows multiple coil structures that are rotationally symmetrical about the axis of the stator core in the same phase stator winding to traverse N slot layers in the corresponding different stator slots when there are many slot layers. It also makes it easier to prevent circulating currents from being generated between branches of the same phase stator winding when switching between various wiring relationships at the input and output ends of different coil structures.

[0040] Secondly, embodiments of this application provide an electric motor, including a rotor and a stator assembly as described in any of the above embodiments, the stator assembly being used to drive the rotor to rotate.

[0041] Thirdly, embodiments of this application provide a vehicle, including a vehicle body and a motor as described in any of the above embodiments, wherein the motor is disposed on the vehicle body. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 A winding schematic diagram of a stator assembly provided in an embodiment of this application;

[0044] Figure 2 for Figure 1 A wiring diagram of the stator assembly in its first operating mode provided in the diagram;

[0045] Figure 3 for Figure 1 A wiring diagram of the stator assembly in the second operating mode provided in the diagram;

[0046] Figure 4 for Figure 1 The diagram provided shows a wiring diagram of the stator assembly in the third operating mode. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0048] This application provides an electric motor that can be applied to vehicles, industrial equipment, and other fields. The motor includes a rotor and a stator assembly, the stator assembly being used to drive the rotor to rotate.

[0049] In some examples, the rotor may be fitted inside the stator assembly.

[0050] In some examples, the rotor may be fitted over the outside of the stator assembly.

[0051] In some examples, the rotor and stator assembly can be arranged opposite each other along the axial direction of the stator assembly.

[0052] In this embodiment, the stator assembly includes a stator core and a three-phase stator winding wound around the stator core. The motor can drive the rotor to rotate by energizing the three-phase stator winding.

[0053] To simultaneously meet the needs of low-speed, high-torque output scenarios such as heavy-load start-up and hill climbing, as well as high-speed output scenarios such as high-speed cruising and high-speed operation, motors often need to switch between different operating conditions, such as low-speed and high-speed operating conditions.

[0054] In related technologies, the three-phase stator windings are fixed, resulting in constant parameters for the motor, such as magnetomotive force, back EMF coefficient, and impedance. The motor exhibits a low current duty cycle and high copper losses in the low-speed range. In the high-speed range, a large amount of field-weakening direct-axis current needs to be injected, which introduces additional copper losses, iron losses, and AC losses. The motor only achieves high efficiency in the low-to-medium speed, medium-load range. Furthermore, these technologies result in a narrow high-efficiency operating range, low average efficiency across all operating conditions, and high energy consumption.

[0055] In addition, in related technologies, in order to meet the requirements of low speed and high torque, the magnetomotive force is often increased by increasing the number of turns of the three-phase stator windings connected in series. However, a large number of turns of the three-phase stator windings connected in series will lead to an excessively high back EMF coefficient. At high speeds, the back EMF is likely to exceed the bus voltage limit, which not only greatly increases the difficulty of field weakening, but also compresses the maximum speed range, making it difficult to balance the high and low speed performance of the motor.

[0056] In addition, in related technologies, the fixed three-phase stator windings are difficult to adapt to the wide range of fluctuating bus voltages (such as voltage fluctuations of up to ±30% during the charging and discharging of power batteries). The high torque output current under low bus voltage results in high current stress on power devices, high heat dissipation costs, and poor system adaptability of the motor.

[0057] Based on this, in the embodiments of this application, the stator assembly further includes a controller, and each phase stator winding includes multiple coil structures that are rotationally symmetrical about the axis of the stator core, and the input and output ends of the coil structures are electrically connected to the controller.

[0058] In some examples, the controller is used to switch the series-parallel connection of different coil structures in the same phase stator winding.

[0059] In this way, by changing the series and parallel connection relationship of different coil structures in the same phase stator winding, the number of branches and turns of the same phase stator winding can be adjusted, so that the motor's magnetomotive force, back EMF coefficient, impedance parameters and other parameters can be adjusted according to the motor's operating conditions.

[0060] For example, when the motor is operating at low speed, the stator assembly can be switched to a mode with fewer branches and more turns in series per phase stator winding. When the motor is operating at high speed, the stator assembly can be switched to a mode with more branches and fewer turns in series per phase stator winding.

[0061] For example, the controller is used to switch the series-parallel connection relationship of different coil structures in the same phase stator winding by switching the connection relationship of the input and output terminals of different coil structures in the same phase stator winding.

[0062] In some examples, the controller is used to switch the three-phase stator windings between a star connection and a delta connection.

[0063] In this way, the number of turns of the three-phase stator winding can be adjusted by switching the three-phase stator winding between a star connection and a delta connection, so that the motor's magnetomotive force, back EMF coefficient, impedance parameters and other parameters can be adjusted according to the motor's operating conditions.

[0064] For example, the controller is used to switch the three-phase stator windings between a star connection state and a delta connection state by switching the wiring relationship between the input and output terminals of the coil structures of different phase stator windings.

[0065] In some examples, the controller is used to switch the series-parallel connection of different coil structures in the same phase stator winding, and to switch the three-phase stator winding between a star connection and a delta connection.

[0066] In this embodiment, the controller switches to adjust parameters such as the motor's magnetomotive force (MTF), back EMF coefficient, and impedance parameters according to the motor's operating conditions. This increases the motor's MMF at low speeds, resulting in greater output torque at the same current, thus reducing current demand and DC copper losses, leading to lower energy consumption and higher efficiency at low speeds. Conversely, it reduces the back EMF coefficient at high speeds, resulting in a lower back EMF at the same speed, thus reducing field weakening current demand and minimizing field weakening losses and AC additional losses at high speeds, resulting in lower energy consumption and higher efficiency at high speeds. This expands the motor's efficient operating range, improves the average efficiency across all operating conditions, and reduces energy consumption.

[0067] By increasing the magnetomotive force of the motor when it is operating at low speed, the controller can also be prevented from operating in a small duty cycle range when the motor is operating at low speed, thus improving the controller's operating efficiency.

[0068] By increasing the motor's magnetomotive force (EMF) at low speeds and decreasing its back EMF coefficient at high speeds, the motor can meet the demand for high torque at low speeds while maintaining a low back EMF at high speeds, making it less likely to exceed bus voltage limits. A lower back EMF at high speeds reduces the need for field weakening current and simplifies field weakening, resulting in less field weakening loss and additional AC losses. This allows for increasing the motor's maximum speed to meet the demands of high-speed electric drives. Thus, a balance can be struck between high- and low-speed performance.

[0069] By switching the controller, the magnetomotive force, back EMF coefficient, impedance parameters and other parameters of the motor can be adjusted according to the motor's operating conditions. This allows the three-phase stator windings to adapt to a wider range of fluctuating bus voltages. It also allows for lower high-torque output current under low bus voltage, which helps reduce current stress on power devices and lower heat dissipation costs. The motor has good system adaptability.

[0070] Each phase stator winding comprises multiple coil structures that are rotationally symmetrical about the axis of the stator core. This ensures that the magnetic field distribution and potential balance are identical across all coil structures in each phase stator winding. The input and output terminals of the coil structures serve as switching points, allowing for seamless connection of the entire coil structure. This facilitates switching between different connection relationships at the input and output terminals of different coil structures, ensuring identical magnetic field distribution and potential balance across all branches of the same phase stator winding. It also minimizes the generation of circulating currents between branches, significantly reducing additional AC copper losses at high frequencies, improving motor efficiency during high-speed operation, and reducing the likelihood of localized overheating in the three-phase stator windings, thus extending the motor's lifespan.

[0071] For example, the controller integrates a control chip and a switching circuit. The input and output terminals of the coil structure are electrically connected to the switching circuit. The control chip can be used to control the on / off state of the switching circuit, so as to switch the connection relationship of the coil structure through the switching circuit.

[0072] For example, the controller can be controlled by software.

[0073] For example, the motor can be a flat wire motor, and the stator assembly can be a flat wire stator assembly.

[0074] Figure 1 This is a schematic diagram of a winding of a stator assembly provided in an embodiment of this application. Figure 2 for Figure 1 The diagram provided shows a wiring diagram of the stator assembly in its first operating mode. Figure 3 for Figure 1 The diagram provided shows a wiring diagram of the stator assembly in its second operating mode. Figure 4 for Figure 1 The diagram provided shows a wiring diagram of the stator assembly in the third operating mode. From top to bottom, the diagrams show the winding diagrams of the first, second, third, fourth, fifth, and sixth coil structures of one phase of the stator winding. The horizontally arranged numbers represent the stator slot numbers, and the vertically arranged numbers represent the slot layer numbers.

[0075] like Figure 1 As shown, in some possible implementations, the stator core has multiple stator slots arranged circumferentially along the stator core, the coil structure corresponds to the multiple stator slots, and the stator slots are divided into N slot layers along the radial direction of the stator core.

[0076] The coil structure includes multiple hairpin coils, which are formed from flat wire conductors. The coil structure is wound around corresponding stator slots via the hairpin coils. The input end of the coil structure is led out from the hairpin coil located at the beginning of the coil structure, and the output end of the coil structure is led out from the hairpin coil located at the end of the coil structure.

[0077] The hairpin coil connects two adjacent slot layers across layers. The coil structure traverses N slot layers in different stator slots through the hairpin coil. The coil structure occupies at least one slot layer in each corresponding stator slot.

[0078] This allows for adjustments to parameters such as magnetomotive force, back EMF coefficient, and impedance parameters of the flat wire motor according to its operating conditions. This improves the average efficiency of the flat wire motor across all operating conditions, balances its high and low speed performance, enhances system adaptability, and increases the operating efficiency of the controller used to control the flat wire motor. Furthermore, it eliminates the potential phase difference caused by the different positions of different coil structures in the stator slots of the same phase stator winding. The input and output terminals of the coil structure serve as switching points, with the entire coil structure connected. This facilitates switching between different wiring relationships at the input and output terminals of different coil structures, eliminating the potential phase difference caused by the different positions of different branches of the same phase stator winding in the stator slots. It also reduces the likelihood of circulating currents between branches, decreases additional AC copper losses at high frequencies, improves motor efficiency at high speeds, and prevents localized overheating of the three-phase stator windings, thus extending the motor's lifespan. Additionally, the hairpin coils connecting adjacent slot layers across layers allow for a smaller size of each phase stator winding, contributing to a smaller overall size of the flat wire motor.

[0079] For example, the N slot layers are numbered sequentially from the first slot layer to the Nth slot layer, from the side closest to the axis of the stator core to the side furthest from the axis of the stator core.

[0080] The hairpin coil is inserted into two different stator slots. A cross-layer connection of the hairpin coil refers to the portion of the hairpin coil located in two different stator slots situated in slots with different numbering layers.

[0081] For example, the hairpin coil includes two parallel straight segments and a connecting segment connecting the two straight segments. The two straight segments of the hairpin coil are respectively inserted into two different stator slots, and the connecting segment is located outside the stator slots. The connecting segment can be U-shaped or V-shaped.

[0082] In some possible implementations, one of the input and output ends of the coil structure is led out from the first slot layer, and the other of the input and output ends of the coil structure is led out from the Nth slot layer.

[0083] This allows multiple coil structures that make the same phase stator winding rotationally symmetrical about the axis of the stator core to traverse N slot layers in the corresponding different stator slots and occupy at least one slot layer in each corresponding stator slot. This makes it easier to prevent circulating currents from being generated between the branches of the same phase stator winding when switching the input and output terminals of different coil structures to various connection relationships.

[0084] In some possible implementations, the stator core has 6m poles, where the number of poles refers to the number of magnetic poles after the stator assembly is energized. Each pole of each phase stator winding corresponds to 3 stator slots, where m is a positive integer and N is an even number.

[0085] The stator windings of each phase have a partial coil structure of type I and a partial coil structure of type II.

[0086] The first type of coil structure starts from the first slot layer and alternately winds between two adjacent slot layers. After passing through each pole, it winds in a direction away from the axis of the stator core to the next adjacent slot layer, until it alternately winds through each pole between the (N-1)th slot layer and the Nth slot layer. The inlet of the first type of coil structure is led out from the first slot layer, and the outlet of the first type of coil structure is led out from the Nth slot layer.

[0087] The second type of coil structure starts from the Nth slot layer and alternately winds between two adjacent slot layers. After passing through each pole, it winds towards the axis of the stator core to the adjacent upper slot layer, until it alternately winds between the second slot layer and the first slot layer to pass through each pole. The input end of the second type of coil structure is led out from the Nth slot layer, and the output end of the second type of coil structure is led out from the first slot layer.

[0088] This allows multiple coil structures that make the same phase stator winding rotationally symmetrical about the axis of the stator core to traverse N slot layers in the corresponding different stator slots and occupy at least one slot layer in each corresponding stator slot. This makes it easier to prevent circulating currents from being generated between the branches of the same phase stator winding when switching the input and output terminals of different coil structures to various connection relationships.

[0089] For example, the number of poles of the stator core can be 6.

[0090] For example, the number of stator slots in the stator core can be 54.

[0091] In some possible implementations, each coil structure includes three hairpin coils with different pitches, designated as a first hairpin coil, a second hairpin coil, and a third hairpin coil. The first hairpin coil has a pitch of 8, the second hairpin coil has a pitch of 9, and the third hairpin coil has a pitch of 11. The pitch of the hairpin coil is the number of stator slots traversed between two straight segments of the hairpin coil.

[0092] In this way, multiple coil structures that allow the same phase stator winding to rotate symmetrically around the axis of the stator core can traverse N slot layers in corresponding different stator slots and occupy at least one slot layer in each corresponding stator slot. At the same time, fewer types of hairpin coils are required, which helps to save on manufacturing mold costs and increase production cycle time.

[0093] In some possible implementations, each phase stator winding includes six coil structures, namely a first coil structure, a second coil structure, a third coil structure, a fourth coil structure, a fifth coil structure, and a sixth coil structure.

[0094] Among them, the first coil structure, the third coil structure, and the fifth coil structure are one of the first type of coil structure and the second type of coil structure, while the second coil structure, the fourth coil structure, and the sixth coil structure are the other of the first type of coil structure and the second type of coil structure.

[0095] This facilitates switching between various series and parallel connection methods for the coil structure of each phase stator winding, and makes it easier to prevent circulating currents from being generated between branches of the same phase stator winding when switching the input and output terminals of different coil structures to various connection relationships.

[0096] In some possible implementations, N≤6, the coil structure occupies one slot layer in each corresponding stator slot.

[0097] This allows multiple coil structures that are rotationally symmetrical about the axis of the stator core in the same phase stator winding to traverse N slot layers in the corresponding different stator slots when the number of stator slot layers is small. It also makes it easier to prevent circulating currents from being generated between branches of the same phase stator winding when switching between various wiring relationships at the input and output ends of different coil structures.

[0098] In some examples, N=6.

[0099] In some possible implementations, N > 6, the coil structure occupies at least two slot layers in the corresponding at least part of the stator slot, and there is a gap of 5 slot layers between adjacent slot layers in the multiple slot layers occupied by the coil structure in the same stator slot.

[0100] This allows multiple coil structures that are rotationally symmetrical about the axis of the stator core in the same phase stator winding to traverse N slot layers in the corresponding different stator slots when there are many slot layers. It also makes it easier to prevent circulating currents from being generated between branches of the same phase stator winding when switching between various wiring relationships at the input and output ends of different coil structures.

[0101] In some examples, N=8 or N=10, the coil structure occupies two slot layers in the corresponding part of the stator slot and one slot layer in the corresponding part of the stator slot.

[0102] For example, N=6, the number of poles of the stator core is 6, the number of stator slots of the stator core is 54, each phase stator winding has 3 stator slots per pole, and the stator slots of the stator core are numbered sequentially in a clockwise or counterclockwise direction, i(j) represents the j-th slot layer of the stator slot with slot number i. For example, 3(2) represents the second slot layer of the stator slot with slot number 3. The first coil structure, the third coil structure and the fifth coil structure are the first type of coil structure, and the second coil structure, the fourth coil structure and the sixth coil structure are the second type of coil structure.

[0103] like Figure 1 As shown, the winding method of the first coil structure of a certain phase stator winding is: 3(1)→12(2)→20(1)→29(2)→37(1)→46(2)→1(3)→10(4)→21(3)→30(4)→38(3)→47(4)→2(5)→11(6)→19(5)→28(6)→39(5)→48(6).

[0104] The winding method of the second coil structure of the stator winding of this phase is as follows: 2 (6) → 47 (5) → 39 (6) → 30 (5) → 19 (6) → 10 (5) → 1 (4) → 46 (3) → 38 (4) → 29 (3) → 21 (4) → 12 (3) → 3 (2) → 48 (1) → 37 (2) → 28 (1) → 20 (2) → 11 (1).

[0105] The winding method of the third coil structure of the stator winding of this phase is as follows: 1(1)→10(2)→21(1)→30(2)→38(1)→47(2)→2(3)→11(4)→19(3)→28(4)→39(3)→48(4)→3(5)→12(6)→20(5)→29(6)→37(5)→46(6).

[0106] The winding method of the fourth coil structure of the stator winding of this phase is as follows: 3 (6) → 48 (5) → 37 (6) → 28 (5) → 20 (6) → 11 (5) → 2 (4) → 47 (3) → 39 (4) → 30 (3) → 19 (4) → 10 (3) → 1 (2) → 46 (1) → 38 (2) → 29 (1) → 21 (2) → 12 (1).

[0107] The winding method of the fifth coil structure of the stator winding of this phase is as follows: 2(1)→11(2)→19(1)→28(2)→39(1)→48(2)→3(3)→12(4)→20(3)→29(4)→37(3)→46(4)→1(5)→10(6)→21(5)→30(6)→38(5)→47(6).

[0108] The winding method of the sixth coil structure of the stator winding is as follows: 1 (6) → 46 (5) → 38 (6) → 29 (5) → 21 (6) → 12 (5) → 3 (4) → 48 (3) → 37 (4) → 28 (3) → 20 (4) → 11 (3) → 2 (2) → 47 (1) → 39 (2) → 30 (1) → 19 (2) → 10 (1).

[0109] For example, the stator windings of the other two phases can be obtained by rotating the corresponding slots around the axis of the stator core.

[0110] like Figures 1-4 As shown, in some possible implementations, the stator assembly has at least two of a first operating mode, a second operating mode, and a third operating mode, and the controller is capable of switching the stator assembly between at least two of the first operating mode, the second operating mode, and the third operating mode.

[0111] like Figure 2 As shown, when the stator assembly is in the first working mode, the three-phase stator windings are in a star connection state, and the first coil structure, second coil structure, third coil structure, fourth coil structure, fifth coil structure and sixth coil structure of the same phase stator winding are connected in series.

[0112] like Figure 3As shown, when the stator assembly is in the second working mode, the three-phase stator windings are in a star connection state. The first coil structure, the second coil structure and the third coil structure of the same phase stator winding are connected in series to form the first branch. The fourth coil structure, the fifth coil structure and the sixth coil structure of the same phase stator winding are connected in series to form the second branch. The first branch and the second branch of the same phase stator winding are connected in parallel.

[0113] like Figure 4 As shown, when the stator assembly is in the third working mode, the three-phase stator windings are in a star connection state. The first coil structure and the second coil structure of the same phase stator winding are connected in series to form the third branch. The third coil structure and the fourth coil structure of the same phase stator winding are connected in series to form the fourth branch. The fifth coil structure and the sixth coil structure of the same phase stator winding are connected in series to form the fifth branch. The third, fourth and fifth branches of the same phase stator winding are connected in parallel.

[0114] In this way, the stator assembly can be switched between at least two of the first, second, and third operating modes by the controller to adjust the number of branches and turns of the same phase stator winding. This allows parameters such as the motor's magnetomotive force, back EMF coefficient, and impedance parameters to be adjusted according to the motor's operating conditions. This improves the average efficiency of the flat wire motor under all operating conditions, balances its high and low speed performance, enhances its system adaptability, and increases the operating efficiency of the controller used to control the flat wire motor. When the stator assembly is in the first, second, and third operating modes, circulating currents are less likely to occur between the branches of each phase stator winding.

[0115] For example, the stator assembly has a first operating mode, a second operating mode and a third operating mode, and the controller is able to switch the stator assembly between the first operating mode, the second operating mode and the third operating mode.

[0116] In some possible implementations, the stator assembly has at least two of a first operating mode, a second operating mode, a third operating mode, and a fourth operating mode, and the controller is capable of switching the stator assembly between at least two of the first operating mode, the second operating mode, the third operating mode, and the fourth operating mode.

[0117] When the stator assembly is in the fourth operating mode, the three-phase stator windings are in a star connection state, and the first, second, third, fourth, fifth and sixth coil structures of the same phase stator winding are connected in parallel.

[0118] In this way, the stator assembly can be switched between at least two of the first, second, third, and fourth operating modes by the controller, allowing for more precise adjustment of parameters such as the motor's magnetomotive force, back EMF coefficient, and impedance parameters according to the motor's operating conditions. When the stator assembly is in the first, second, third, or fourth operating modes, circulating currents are less likely to occur between the branches of each phase stator winding.

[0119] For example, the stator assembly has a first operating mode, a second operating mode, a third operating mode and a fourth operating mode, and the controller is capable of switching the stator assembly between the first operating mode, the second operating mode, the third operating mode and the fourth operating mode.

[0120] The solution provided in this application embodiment can meet the requirements of low-speed high torque, high-speed wide speed range, high efficiency and high reliability under all operating conditions without significantly increasing the complexity and cost of the motor.

[0121] This application also provides a vehicle, including a vehicle body and a motor as described in any of the above embodiments, with the motor disposed on the vehicle body. This allows the vehicle to have higher energy efficiency, longer driving range, and better performance at both high and low speeds.

[0122] For example, the vehicle may include, but is not limited to, electric vehicles, motor vehicles, trams, etc.

[0123] For example, when the vehicle is in low-speed, high-torque conditions such as starting, climbing, or accelerating from 0 to 100 km / h, the stator assembly can be switched to the first operating mode. When the vehicle is in high-speed cruising or high-speed driving conditions, the stator assembly can be switched to the second operating mode. When the vehicle is in urban commuting conditions, the stator assembly can be switched to the third operating mode.

[0124] It should be noted that the terms "one embodiment," "embodiment," "exemplary embodiment," "some embodiments," etc., mentioned in the specification indicate that the described embodiment may include a specific feature, structure, or characteristic, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments, whether explicitly described or not, is within the knowledge scope of those skilled in the art.

[0125] Generally speaking, terms should be understood at least in part by their use in context. For example, at least in part by context, the term "one or more" as used in the text can be used to describe any feature, structure, or characteristic of the singular meaning, or a combination of features, structures, or characteristics of the plural meaning. Similarly, at least in part by context, terms such as "a" or "the" can also be understood to convey either singular or plural usage.

[0126] It should be readily understood that the terms “on,” “above,” and “on top of” in this application should be interpreted in the broadest possible sense, such that “on” means not only “directly on something” but also “on something” with an intermediate feature or layer therebetween, and that “above” or “on top of” means not only “on something” but also “on something” without an intermediate feature or layer therebetween (i.e., directly on something).

[0127] Furthermore, for ease of explanation, spatially relative terms such as "below," "below," "under," "above," and "above" may be used to describe the relationship of one element or feature relative to other elements or features as shown in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation other than those shown in the figures. The device may have other orientations (rotated 90° or in other orientations), and the spatially relative descriptive terms used herein may be interpreted accordingly.

[0128] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A stator assembly, characterized in that, It includes a stator core, a three-phase stator winding wound around the stator core, and a controller; Each phase of the stator winding includes multiple coil structures that are rotationally symmetrical about the axis of the stator core, and the input and output ends of the coil structures are electrically connected to the controller. The controller is used to switch the series-parallel connection relationship of different coil structures in the same phase of the stator winding; and / or, the controller is used to switch the three-phase stator winding between a star connection state and a delta connection state.

2. The stator assembly according to claim 1, characterized in that, The stator core has a plurality of stator slots arranged circumferentially along the stator core, the coil structure corresponds to the plurality of stator slots, and the stator slots are divided into N slot layers along the radial direction of the stator core; The coil structure includes multiple hairpin coils, and the coil structure is wound around the corresponding stator slots through the hairpin coils. The input end of the coil structure is led out from the hairpin coil located at the first end of the coil structure, and the output end of the coil structure is led out from the hairpin coil located at the end of the coil structure. The hairpin coil connects two adjacent slot layers across layers, and the coil structure traverses the N slot layers in the corresponding different stator slots through the hairpin coil. The coil structure occupies at least one slot layer in each corresponding stator slot.

3. The stator assembly according to claim 2, characterized in that, The N slot layers are numbered sequentially from the first slot layer to the Nth slot layer, from the side closest to the axis of the stator core to the side furthest from the axis of the stator core. One of the input and output terminals of the coil structure is led out from the first slot layer, and the other of the input and output terminals of the coil structure is led out from the Nth slot layer.

4. The stator assembly according to claim 3, characterized in that, The stator core has 6m poles, and each pole of each phase of the stator winding corresponds to 3 stator slots, where m is a positive integer and N is an even number; The stator winding of each phase has a portion of the coil structure of the first type of coil structure and a portion of the coil structure of the second type of coil structure; The first type of coil structure starts from the first slot layer and alternately winds between two adjacent slot layers. After passing through each pole, it winds in a direction away from the axis of the stator core to the next adjacent slot layer, until it alternately winds through each pole between the (N-1)th slot layer and the Nth slot layer. The inlet of the first type of coil structure is led out from the first slot layer, and the outlet of the first type of coil structure is led out from the Nth slot layer. The second type of coil structure starts from the Nth slot layer and alternately winds between two adjacent slot layers. After passing through each pole, it winds towards the axis of the stator core to the adjacent upper slot layer until it alternately winds through each pole between the second slot layer and the first slot layer. The input end of the second type of coil structure is led out from the Nth slot layer, and the output end of the second type of coil structure is led out from the first slot layer.

5. The stator assembly according to claim 4, characterized in that, Each of the coil structures includes three different pitch hairpin coils, namely a first hairpin coil, a second hairpin coil, and a third hairpin coil; The first hairpin coil has a pitch of 8, the second hairpin coil has a pitch of 9, and the third hairpin coil has a pitch of 11.

6. The stator assembly according to claim 4, characterized in that, Each phase of the stator winding includes six coil structures, namely a first coil structure, a second coil structure, a third coil structure, a fourth coil structure, a fifth coil structure, and a sixth coil structure; Wherein, the first coil structure, the third coil structure, and the fifth coil structure are one of the first type of coil structure and the second type of coil structure, and the second coil structure, the fourth coil structure, and the sixth coil structure are the other of the first type of coil structure and the second type of coil structure.

7. The stator assembly according to claim 6, characterized in that, The stator assembly has at least two of a first operating mode, a second operating mode, and a third operating mode, and the controller enables the stator assembly to switch between at least two of the first operating mode, the second operating mode, and the third operating mode; When the stator assembly is in the first working mode, the three-phase stator windings are in a star connection state, and the first coil structure, the second coil structure, the third coil structure, the fourth coil structure, the fifth coil structure and the sixth coil structure of the same phase stator winding are connected in series. When the stator assembly is in the second working mode, the three-phase stator windings are in a star connection state. The first coil structure, the second coil structure, and the third coil structure of the same phase stator winding are connected in series to form a first branch. The fourth coil structure, the fifth coil structure, and the sixth coil structure of the same phase stator winding are connected in series to form a second branch. The first branch and the second branch of the same phase stator winding are connected in parallel. When the stator assembly is in the third operating mode, the three-phase stator windings are in a star connection state. The first coil structure and the second coil structure of the stator winding in the same phase are connected in series to form a third branch. The third coil structure and the fourth coil structure of the stator winding in the same phase are connected in series to form a fourth branch. The fifth coil structure and the sixth coil structure of the stator winding in the same phase are connected in series to form a fifth branch. The third branch, the fourth branch and the fifth branch of the stator winding in the same phase are connected in parallel.

8. The stator assembly according to claim 4, characterized in that, If N≤6, the coil structure occupies one slot layer in each of the corresponding stator slots; or... N > 6, the coil structure occupies at least two slot layers in the corresponding at least part of the stator slots, and the coil structure occupies a plurality of slot layers in the same stator slot with a gap of 5 slot layers between adjacent slot layers.

9. An electric motor, characterized in that, It includes a rotor and a stator assembly as described in any one of claims 1-8, the stator assembly being used to drive the rotor to rotate.

10. A vehicle, characterized in that, Includes the vehicle body and the motor as described in claim 9; The motor is located on the vehicle body.

Images