Hairpin winding electric machine and method

Abstract

Hairpin-wound motor machine and method. This invention relates to a motor winding design method that enables high parallel paths per phase in both high-speed and low-speed motors. The method includes using multiple parallel paths per phase, where each parallel path occupies one slot per pole, and the winding configuration includes forward and backward parallel paths. The design is characterized by a layered winding configuration with at least two layers, where jumpers connect different layers. Additionally, the method includes a flexible mechanism that supports scalable configurations for various motor types, including 3-phase and 6-phase systems. This method improves motor performance and efficiency while providing adaptable design options.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Patent Application No. 19 / 007,448 (Attorney’s File No. CI-23-0638-01-US), filed December 31, 2024, entitled “Uniform Hairpin Winding Connection Method,” the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] This invention relates to hairpin-type winding electric motors and methods. Background Technology

[0004] The electric motor, a key component of electric drive systems, has received increasing attention. The electric motor is electrically connected to the traction battery and provides torque to the driven wheels. The electric drive system consists of the electric motor, an inverter, and an optional gearbox, where the inverter receives DC power from the battery and converts it to DC or AC power to drive the motor. The machine typically includes a stator and a rotor, which work together to convert electrical energy into mechanical motion. The main focus is on maximizing power, torque density, and efficiency while minimizing the weight of the electric motor. While EVs offer several advantages over internal combustion engine-driven vehicles, one issue is their limited range, especially for vehicles without a range extender for the internal combustion engine.

[0005] To address this issue, a technique is needed to improve the efficiency of electrical use in "electric motors" or "electric traction motors." The key to achieving this lies in increasing the slot fill factor of the windings, leading to a revolution in winding technology. Hairpin windings are an increasingly popular technology in the automotive industry because they allow for the design of more efficient motors with less space and lighter weight. Additionally, increased peak speeds are desirable, but this can lead to increased heat due to losses in the windings, making it necessary to reduce winding losses.

[0006] In conclusion, an improved electric motor is still needed to overcome these shortcomings. Significant progress can be made in manufacturing electric vehicles that are more competitive and affordable for everyone while reducing their environmental impact by incorporating innovative technologies such as hairpin windings. Summary of the Invention

[0007] This section provides an overview of a practical implementation of the motor winding design method described in the claims, demonstrating its application in various motor configurations. The method can be implemented in both high-speed and low-speed motors, highlighting its versatility and the benefits of highly parallel path configurations across different motor types. By using a layered winding configuration with jumpers and implementing forward and backward parallel paths, the method offers flexibility and scalability. It is also applicable to 3-phase and 6-phase systems, thereby optimizing motor performance and efficiency in practical applications.

[0008] One implementation describes a method for generating hairpin windings, wherein the maximum number of parallel paths for each phase is equal to twice the number of pole pairs. This method ensures that each parallel path traverses all slots for each pole of each phase, including all hairpin layers, while maintaining the same number of conductors in each parallel path regardless of the slot location. Another implementation further improves the method by adding flexibility by specifying that each parallel path begins at the innermost or outermost layer of the hairpin layer. Furthermore, the hairpin winding is described as an integrated slot-distributed winding, thereby improving overall efficiency and design adaptability.

[0009] In other implementations, this method incorporates features such as layer change prior to phasor change. This is achieved by using a single type of normal hairpin with a specific winding slot pitch and weld side, ensuring uniformity of the winding structure. Phasor change is achieved via jumpers with a jumper slot pitch equal to the winding slot pitch, which can be adjusted by integers. Phasor change can occur in the innermost or outermost layer, or in both, allowing for greater control over the motor's electrical characteristics.

[0010] This method has been further applied to electric machines, including motors and generators. This is particularly beneficial for motors (e.g., traction motors for electric vehicles), where the design optimizes efficiency and reduces AC losses. The system used for stator assemblies in these motors incorporates a winding scheme that spans all slots of each pole of each phase, where jumpers ensure phase alignment. Furthermore, the system supports both full-pitch and short-pitch windings and can be adapted to multiple three-phase windings with or without angular offset.

[0011] The motor winding design is scalable, allowing easy conversion between 3-phase and 6-phase systems and adaptable to a range of slot-pole combinations, motor sizes, and power outputs. It also supports the use of conductors with equal and unequal lead lengths for jumper connections between layers. The method also includes a flexible mechanism that allows for variations in the number of parallel paths per phase without altering the core assembly method. This winding system is designed to minimize manufacturing complexity and cost, increase production efficiency, and reduce the need for specialized equipment.

[0012] Overall, these implementations demonstrate the versatility, scalability, and efficiency of the motor winding design approach, making it suitable for a wide range of motor applications, from high-power, high-efficiency motors to cost-effective solutions for smaller motors. This approach optimizes performance, improves torque and power density, and simplifies manufacturing processes, providing a universal solution for modern motor design. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of a dual-axle multi-mode adjustable hybrid vehicle system with an integrated front axle.

[0014] Figure 2 This is a schematic diagram of an integrated shaft;

[0015] Figure 3 This is a schematic diagram of another dual-axis multi-mode adjustable hybrid vehicle system with an integrated front axle.

[0016] Figure 4 This is a schematic diagram of an example of a three-axis multi-mode adjustable hybrid vehicle system with an integrated front axle;

[0017] Figure 5 This is a schematic diagram of an example of a three-axis multi-mode adjustable hybrid vehicle system with an integrated front axle;

[0018] Figure 6 This is a schematic diagram of an example of a three-axis multi-mode adjustable hybrid vehicle system with an integrated front axle;

[0019] Figure 7 This is a schematic diagram of a controller that is operatively coupled to other components of the system;

[0020] Figure 8 It is a schematic diagram showing several detailed aspects of an electric machine.

[0021] It may require bearings on both sides, and because it rotates, the air gap between the stator and rotor needs to be clearly visible.

[0022] Figure 9 yes Figure 8 A plan view of the stator of the electric motor in the diagram, where Figure 9A This is a close-up view showing the winding layers of the stator. The stator of the electric machine is equipped with hairpin windings.

[0023] Figure 10 This is the phasor diagram of an electric motor, which includes 36 slots and 6 poles with full-pitch windings.

[0024] Figure 11AThis is a diagram of a winding scheme with diagonal hairpin windings for a 36-slot 6-pole electric motor with full-pitch windings. This diagram shows the winding of each phase of the 36-slot 6-pole electric motor with 6 parallel paths (npp=2p), showing only phase A. Diagrams for phases B and C are not shown, but can be easily obtained by shifting 120 electrical angles. For this 36-slot 6-pole electric motor, 120 electrical angles correspond to 40 mechanical angles and 4 slots.

[0025] Figure 11B yes Figure 11A The continuation of the diagram in the text.

[0026] Figure 11C Examples of paths A1, A2, A3, A4, A5, and A6 are shown for a 36-slot, 6-pole electric motor with full-pitch windings. The winding configuration shown has four layers (layers 1 to 4), each consisting of parallel paths spanning the slots. The parallel paths are labeled A1, A2, A3, A4, A5, and A6, corresponding to the slots and layers of the stator. The winding design is configured with 6 parallel paths per phase, where each path occupies a slot in each layer of the stator. The winding follows the pattern of a full-pitch winding, where nL=4, npp=2p=6, p=3, and q=2, thereby ensuring proper phase alignment and efficiency in the electric motor.

[0027] Figure 11D The diagram illustrates the phase connections of a 36-slot, 6-pole electric motor with full-pitch windings. The figure shows three phases (A, B, and C) of the motor, each consisting of six parallel paths labeled A1-A6, B1-B6, and C1-C6. The connections are arranged such that each phase is represented by a set of parallel paths with alternating positive and negative terminals for proper phase alignment. The winding configuration follows a full-pitch design with parameters set to nL=4, npp=2p=6, p=3, and q=2, ensuring efficient motor operation and correct phase distribution.

[0028] Figure 12 It is shown in the use of Figure 11A and Figure 11B A diagram showing the assembly steps of pins and jumpers arranged inside the stator core of an electric motor.

[0029] Figure 13 This diagram illustrates an alternative diagonal hairpin winding scheme for an electric machine comprising 36 slots and 6 poles, with a full-pitch winding, such that n pp =2p / 2, p>q, p=3, and q=2. It is a winding diagram showing 3 (npp=2p / 2) parallel paths per phase of a 36-slot 6-pole electric motor.

[0030] Figure 14It is a diagram showing a diagonal hairpin winding scheme for an electric machine, which includes 36 slots, 6 poles, with a full pitch winding, n pp = 2p / 3, such that p > q, p = 3, and q = 2. It is a winding diagram showing 2 (npp = 2p / 3) parallel paths per phase for a 36-slot 6-pole electric machine.

[0031] Figures 15A to 15C It is a diagram showing an example layout of an electric machine with 36 slots and 6 poles in full pitch and short pitch windings, where p > q, p = 3, and q = 2.

[0032] Figure 16 It is a diagram showing a diagonal hairpin winding scheme for an electric machine, which includes 36 slots and 6 poles, with a short pitch winding, where n pp = 2p, p > q, p = 3, q = 2. The previous diagram is for a full pitch winding, while this diagram is for a short pitch winding.

[0033] Figure 17A It is a diagram showing a diagonal hairpin winding scheme for an electric machine including 54 slots and 6 poles, where p = q = 3, with a full pitch winding.

[0034] Figure 17B It is Figure 17A a continuation of the diagram in

[0035] Figure 18A It is a diagram showing a diagonal hairpin winding scheme for an electric machine including 72 slots and 6 poles, where p < q, p = 3, q = 4, with a full pitch winding.

[0036] Figure 18B It is Figure 18A a continuation of the diagram in

[0037] Figure 19 It is a diagram showing a modification to the unified diagonal hairpin winding scheme using the fly wire jumper concept.

[0038] Figure 20 It is a diagram showing an electric machine with 36 slots and 6 poles having a full pitch winding (similar to case 1a, where n pp = 2p = 6).

[0039] Figure 21 It is a diagram showing a perspective view of a 3D model of a 96-slot 8-pole electric machine with a short pitch winding.

[0040] Figure 22This figure illustrates an embodiment of paths A1, A2, A3, A4, A5, and A6 for a 72-slot, 6-pole electric machine with full-pitch windings. The winding configuration is shown spanning four layers, with parallel paths (A1-A6) arranged through the slots in a specific order. This arrangement is designed using a jumper-flying method, where the winding paths alternate between different layers to optimize phase alignment. The figure also includes parameters for the machine, where nL=4, npp=2, p=6, p=3, and q=2, following a full-pitch winding design. This figure illustrates how this alternative method using jumpers-flying wires ensures efficient phase distribution and improves machine performance.

[0041] Figure 23 It is the layout of the winding scheme for a 36-slot, 6-pole electric motor with full-pitch winding.

[0042] Figure 24A This is a flowchart of a method for generating a hairpin winding for an electric motor. This disclosure provides an example of each of a plurality of parallel paths starting at the innermost or outermost layer of the hairpin layer. However, the start and end points of these parallel paths can be located anywhere within the winding diagram, depending on the specific design and preference. This positioning is influenced by factors such as the arrangement of terminal buses or connecting loops that connect to the inverter phase leads. For example, in a three-phase motor, there are typically three terminal lines, one for each phase.

[0043] Figure 24B It is based on the example of this disclosure. Figure 24A The continuation of the flowchart in the text.

[0044] Figure 25 This is a diagram of the winding configuration of a 54-slot 6-pole motor with 6 parallel paths per phase, showing the phase A winding layout and the use of jumpers to connect the parallel paths through the various layer groups.

[0045] Figure 26 This is a diagram of a winding design for a 54-slot 6-pole motor with 4-layer hairpin windings, showing how the winding design can be divided into two 2-layer hairpin winding designs with jumpers connecting different layers.

[0046] Figure 27 This is a diagram of the winding configuration of a 96-slot 8-pole motor with 8 parallel paths per phase, showing the first and second parallel paths starting from the top and bottom layers, with the necessary mechanical displacement for phases B and C.

[0047] Figure 28 This is a diagram of the winding design of a 96-slot 8-pole motor with 8 parallel paths per phase, which incorporates 4 layers of hairpin windings. It shows the division into two 2-layer hairpin winding designs, with jumpers used to connect the layers.

[0048] Figure 29 Various winding configurations of a 24-slot, 4-pole motor using different hairpin winding designs are illustrated. The top of the figure shows a three-phase motor configuration with four parallel paths per phase, including phase shifts and corresponding mechanical properties. The middle section presents a four-layer hairpin winding design, demonstrating the jumper connections between different layers. The bottom section depicts a five-layer hairpin winding design, further detailing the inter-layer connections with jumpers. These examples highlight the flexibility and scalability of winding designs for different motor configurations and phase requirements. Detailed Implementation

[0049] This document describes embodiments of the present disclosure. However, it should be understood that the disclosed embodiments are merely examples, and other embodiments may take various and alternative forms. The drawings are not necessarily to scale; some features may be exaggerated or minimized to show detail of particular components. Therefore, the specific structural and functional details disclosed herein should not be construed as limiting, but merely as a representative basis for teaching those skilled in the art to use the invention in various ways. As will be appreciated by those skilled in the art, various features illustrated and described with reference to any of the figures may be combined with features illustrated in one or more other figures to produce embodiments not explicitly illustrated or described. The combinations of features shown provide representative embodiments for typical applications. However, various combinations and modifications of features consistent with the teachings of this disclosure may be desired for particular applications or implementations.

[0050] In electrified vehicles, electric motors convert electricity supplied by batteries into motion to be transmitted to the wheels. In some vehicles, there is a single, centrally located electric motor powering one or more wheels, while in others, one or more wheels have an electric motor (sometimes called a hub motor) located at each driven wheel. An electric motor typically includes a stationary stator with multiple stator slots arranged circumferentially around the stator. Windings are located in the stator slots and carry alternating current (AC) voltage. This can be either alternating current (AC) or direct current (DC), depending on whether the motor is an AC or DC motor, with AC being more commonly used in modern traction motor applications.

[0051] The rotor is disposed within the stator and is used to rotate relative to the stator in response to an AC voltage carried by the windings. This is the case for an internal rotor motor; however, external rotor motors also exist. Although only AC motors are shown, this disclosure is also applicable to DC motors, and will be understood by those skilled in the art to be applicable to DC motors.

[0052] Motion is achieved by generating a rotating magnetic field between the stator and rotor. This action creates thrust and pull between the stator and rotor, causing the rotor to rotate relative to the stator. In the stator, the magnetic field is generated by the current flowing through the windings. For the rotor, there are typically two different main technologies: (i) synchronous motors, where a magnetic field is generated by the windings or permanent magnets in the rotor, and (ii) induction motors or asynchronous motors, which have an induced magnetic field at the rotor. In an induction motor, metal bars (e.g., aluminum or copper bars) in the rotor are within the magnetic field of the stator, causing currents to be induced in them, thereby generating the rotor's magnetic field.

[0053] A hairpin motor is a type of electric motor in which the stator windings are made using hairpins (e.g., instead of round wire). Hairpins are large rectangular wires, and their symmetrical and solid shape makes them easier to wind than round wire, greatly simplifying assembly. Unlike round wire, hairpins can be precisely positioned, resulting in a cleaner design. Round wire requires stitching thread to hold the windings together (a process known as stator clamping). This is not necessary for hairpins.

[0054] Compared to conventional circular wires, the shape factor of hairpins allows for a better fill factor in the stator slots. For example, the rectangular profile of hairpins allows them to be fitted into the stator slots, similar to how the sides of adjacent hairpins fit tightly together within the slots as building blocks. Conversely, a similar structure constructed with the circular profile of conventional wires leaves gaps between adjacent wires. A better fill factor leads to higher efficiency and other benefits. For example, a better fill factor can translate to a smaller stator, and therefore a smaller electric motor.

[0055] Hairpin windings can carry more current than round wires. When compared to conventional motors, motors with hairpin windings can produce the same amount of power using less energy, which helps extend the range of vehicles. This improved efficiency generates less heat in the windings and the motor itself. This simplifies temperature management and improves the reliability and lifespan of the motor.

[0056] In hairpin motors, the hairpins consist of a protective varnish and / or coating. Similar to copper wire, the copper hairpins are coated with a protective varnish (called an insulating layer) that prevents current from flowing in all directions when the hairpins are in contact. Hairpin stators typically use one of the following varnishes: polyamide-imide (PAI), polyetheretherketone (PEEK), and polyamide-imide with polyimide foil (PAI+FEP).

[0057] The hairpin stator is the defining part of a hairpin motor. In the manufacturing process of a hairpin motor, some general steps in the hairpin stator manufacturing process include some or all of the following steps. The hairpin production process involves cutting and bending the hairpin wire into a three-dimensional shape. This process can be carried out in one stage using CNC bending equipment, or in multiple stages using a combination of die bending and rotary bending. The three main bending techniques for hairpin wire are: U-pin, where the wire is shaped like a U (the most common), I-pin, where the wire is shaped like an I, and continuous hairpin (also known as continuous wave), where a single wire is bent into a serpentine shape that can be several meters long.

[0058] The hair clip manufacturing process also includes welding. Here, the ends of the hair clip are welded to ensure that the electrical flux is generated as needed. The quality of the welding process is important for the performance of the electric motor.

[0059] The hairpin manufacturing process also involves stripping (e.g., laser stripping) varnish from the hairpin ends. This step requires removing the varnish before welding to prevent it from contaminating the weld. Mechanical abrasion can be used, but laser stripping is more precise and consistent. An impregnation process can also be used, where a portion of the stator is covered with a powder coating to protect exposed areas that have already been welded.

[0060] For hairpin windings, rectangular conductors are arranged in layers within each slot. Connections are made between the conductors to form the winding, defined by the winding scheme. While most connections in a hairpin winding layout are identical to reduce manufacturing costs, a small number of jumpers are required when parallel branches exist. A typical hairpin winding includes jumpers with open slots, each extending inward from the edge of the jumper to form a three-sided slot designed to receive a rectangular hairpin. This three-sided slot surrounds three sides of the hairpin, leaving a fourth side open. Because the fourth side is not closed, the jumper cannot self-support the hairpin, causing it to slip through the open slot. Therefore, the jumper must be secured during soldering to hold the hairpin in place.

[0061] There are two main types of winding patterns for electric motors. One type of winding pattern that can be constructed is the fractional slot concentrated winding (FSCW) pattern. Another type of winding pattern that can include the windings disclosed herein is the integral slot distributed winding (ISDW) pattern. Typically, the hairpin connection pattern belongs to the latter (ISDW). Existing hairpin connection methods cannot achieve the highest number of n... pp =2p parallel paths per phase, where p is the number of pole pairs. Existing hairpin connection methods require more types of pins.

[0062] As described in more detail below, this disclosure provides a unique connection arrangement for forming windings using a hairpin technique, wherein changes to the basic hairpin geometry are minimal. Minimal modifications are made to a limited number of connections, leaving many hairpin geometries unchanged. Because the geometry remains largely unchanged, the crown-side formation of each hairpin remains simple and abrupt bending of the hairpin conductors during formation is avoided. Furthermore, bending and welding at the solder ends are uniform.

[0063] Furthermore, this invention provides a unique design method in the form of a unified diagonal hairpin connection for all common ISDW scenarios, relevant to potential applications in traction motors and generators. In the electric motor, there are an equal number of north and south magnets facing outwards from the rotor, and each group of N and S magnets is called a pole pair. For each pole pair in the motor, there are two poles; therefore, if the motor has 8 poles / magnets, there are 4 pole pairs. This connection method allows for n poles per phase. pp =2p parallel paths, where p is the pole pair number. The principle disclosed in this paper minimizes the type of needle required, without being limited by the number of hairpin layers. This means that such a principle can be applied to electric machines with any desired number of hairpin layers.

[0064] Now turn to the attached diagram. Figure 1 An example of a multi-mode hybrid vehicle system 200 as disclosed herein is shown. System 200 includes multiple power sources. For example, an integrated shaft 202 is mechanically connected to a steerable front axle 102A, such that the integrated shaft 202 serves as a power source to provide power to drive the front wheels 120A using electrical energy supplied from an energy storage device 110. A rear axle 102B is mechanically connected to a differential gear 116, which is mechanically connected to a transmission 114, which is mechanically engaged or disengaged from an engine 104 via a clutch 112. Thus, the rear axle 102B is controlled using power supplied by the engine 104 (another power source). For simplicity, the inverter for the integrated shaft 202 and the fuel storage device 108 connected to the engine 104 are not shown.

[0065] As disclosed herein, an "integrated shaft" includes a type of electric shaft drive that is fixed to a wheel to rotate it. In examples, the integrated shaft combines an electric motor-generator, power electronics such as an inverter, and, in some examples, the function of a cooling circuit to reduce cost and increase efficiency in a single component. The integrated shaft is neither directly nor indirectly coupled to any internal combustion engine, thus using only the electric motor-generator included therein to provide mechanical power to the drive shaft coupled thereto.

[0066] In some examples, the motor-generator of the integrated shaft can be mounted on the drive shaft. In some embodiments, the integrated shaft is configured to reduce interfaces and components that may cause efficiency losses. Examples of such components include wires and copper cables connecting the components, plugs, bearings for rotating components, and separate cooling circuits for the motor and power electronics. The integrated shaft is also more compact than separately mounted motors, power electronics, and cooling circuits, thus saving installation space within the vehicle chassis frame and allowing for more space therein. Each integrated shaft is configured independently of other integrated shafts in the system. In some examples, the integrated shaft may also include a two-speed or three-speed gearbox.

[0067] like Figure 1 As shown in the embodiment, the integrated shaft 202 and the drive shaft 102 (e.g.) Figure 1 The front axle 102A shown is mechanically connected. The drive axle 102 is mechanically connected to a pair of wheels 120, for example... Figure 1 A pair of front wheels 120A are shown. Although not shown, the controller is electrically connected to the integrated shaft 202. Based on the received input, the controller opens (activates or engages) or closes (deactivates or disengages) one or more of these components to achieve the different modes shown here. Figure 2 Some components of the integrated shaft 202 are shown. For example, the integrated shaft 202 includes a motor-generator 300, a drive shaft 302, and a transmission 304. Other components, such as the aforementioned inverter and / or cooling circuit, may be suitably included in the integrated shaft 202. These components may operate separately from or independently of other components (e.g., the transmission 304 may operate separately from the transmission 114). The components of the integrated shaft 202 (e.g., at least a portion of the motor-generator and drive shaft, etc.) may be mechanically fitted, coupled, secured, or implemented within a common housing 204. The housing may be any suitable structure that supports the positioning of the components and provides protection for them.

[0068] Figure 3 An example of system 200 is shown, which combines two integrated shafts 202A and 202B, each of which implements one shaft, namely the front shaft 102A and the rear shaft 102B. The integrated shafts 202A and 202B are operated using a controller (not shown), and the electrical energy for these shafts is provided by a common energy storage device 110, such as a battery or battery pack. The two integrated shafts 202A and 202B can be operated separately and independently so that they can be implemented as two separate and different power sources. Each integrated shaft may include the same components, including, for example, an electric motor and a transmission, as explained herein, which are operable separately from each other, although they can also be operated simultaneously together, as appropriately controlled by the controller.

[0069] Figures 4 to 6 An example of system 200 is shown, in which more than two axles (and in fact, more than four wheels) are implemented, with different combinations of integrated electric axles and engine drive axles. It should be understood that these figures are provided for illustrative purposes only, so that any additional number of axles can be implemented according to the needs of the vehicle and its operation.

[0070] Figure 4 An example of system 200 is shown, which incorporates three shafts 102A, 102B, and 102C, with two of the shafts, the front shaft 102A and the rear shaft 102C, having integrated shafts 202A and 202B respectively connected to them. As shown, the other shaft (rear shaft) 102B is connected to the engine 104 via a clutch 112, a transmission 114, and a differential gear 116. Integrated shafts 202A and 202B are powered by an energy storage device 110.

[0071] Figure 5 An example of a system 200 with three shafts 102A, 102B, and 102C is shown, but instead of two integrated shafts, only the front shaft 102A is connected to the integrated shaft 202, while the remaining two rear shafts 102B and 102C are connected to differential gears 116A and 116B, respectively. The differential gears 116A and 116B are connected to each other via a drive shaft 122, which can operate both gears simultaneously using power supplied by the engine 104 and transmitted through the transmission 114. Accordingly, the rear shafts 102B and 102C can be connected to each other via a drift shaft 122.

[0072] Figure 6 An example of system 200 is shown, in which all three shafts 102A, 102B, and 102C are powered by energy storage 110. That is, there are three integrated shafts 202A, 202B, and 202C for the three shafts, each of which can operate independently and is controlled by a controller (not shown). In all the examples disclosed herein, the front axle 102A is always implemented using an integrated shaft, but the remaining shafts may have integrated shafts, engine drive shafts, or a combination of both.

[0073] Figure 7An example of a control system 700 for a multi-mode hybrid vehicle system 200 as disclosed herein is shown. The control system 700 includes a controller (multi-axle system controller) 702 that receives inputs 712 and controls outputs 714. The controller 702 includes a processor 704 and a memory unit 706. The processor may be a microprocessor, a microcontroller, or any other suitable type of processing device or controller known in the art. For example, the controller 702 controls the operation of the integrated axle 202 and the engine 104 via communication lines. However, it should be understood that communication between the controller and the integrated axle and the engine may alternatively or additionally be performed wirelessly.

[0074] It should be understood that in some embodiments, controller 702 may form part of a processing subsystem that includes one or more computing devices, processors, or processing circuitry having a non-transient computer-readable storage medium, as well as communication hardware. Controller 702 may be a single device or a distributed device, and the functionality of the controller may be performed by hardware and / or by processing instructions stored on a non-transient machine-readable storage medium. Exemplary processors include application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), digital signal processors (DSPs), and microprocessors including firmware. Exemplary non-transient computer-readable storage media include random access memory (RAM), read-only memory (ROM), flash memory, hard disk storage, electrically erasable and programmable ROM (EEPROM), electrically programmable ROM (EPROM), disk storage, and any other medium that can be used to carry or store processing instructions and data structures and is accessible by a general-purpose or special-purpose computer or other processing device.

[0075] Some operations of the controller 702 described herein include interpreting and / or determining one or more parameters. Parameters may be inputs 712, which may be information or data received from sensors 708 and / or user interface 710, as well as other means of providing input. Sensors may be any suitable sensors capable of measuring the load on the vehicle or any change or increase in the load applied to the vehicle. Sensors may include, but are not limited to: weight sensors that detect the physical weight of the vehicle and / or its cargo; gyroscopes that detect tilting or descent that the vehicle may be traveling in; and altimeters that detect the height or changes in height of the vehicle as it travels.

[0076] As used herein, interpretation or determination includes receiving sensor values ​​by any means known in the art, including receiving values ​​from a data link, network communication, or input device at least via a communication line, receiving electronic signals indicating the value (e.g., voltage, frequency, current, or pulse width modulation signals), such as the current and expected load of the vehicle and user preferences, or whether the rear axle is approaching or reaching its performance limits, for example, receiving computer-generated parameters indicating the value as further explained herein, reading the value from a memory location on a non-transient machine-readable storage medium, receiving values ​​as runtime parameters by any means known in the art, and / or by receiving values ​​that can be calculated from the parameters as interpreted, and / or by referring to default values ​​interpreted as parameter values.

[0077] The embodiments of the technology described herein can be implemented in any of a variety of ways. For example, these embodiments can be implemented using hardware, software, or a combination thereof. When implemented in software, the software code (or software algorithm) can execute on any suitable processor or set of processors, whether provided in a single computing device or distributed among multiple computing devices. Such processors can be implemented as integrated circuits, wherein one or more processors are within integrated circuit components, including commercially available integrated circuit components known by names in this art, such as CPU chips, GPU chips, microprocessors, microcontrollers, or coprocessors. Alternatively, the processor can be implemented in custom circuitry (e.g., ASICs) or in semi-custom circuitry resulting from configuring programmable logic devices. As yet another alternative, the processor can be part of a larger circuit or semiconductor device, whether commercially available, semi-custom, or custom. As a concrete example, some commercially available microprocessors have multiple cores, such that one or a subset of these cores can constitute a processor. However, a processor can be implemented using circuitry of any suitable format.

[0078] Furthermore, it should be understood that a computing device can be implemented in any of several forms, such as a rack-mount computer, desktop computer, laptop computer, or tablet computer. Additionally, a computing device can be embedded in a device that is not typically considered a computing device but has suitable processing capabilities, including a personal digital assistant (PDA), a smartphone, or any other suitable portable or stationary electronic device.

[0079] Similarly, a computing device may have one or more input and output devices. These devices can be used, in particular, to present a user interface 710 (which can be both an output device and an input device). Examples of output devices that can be used to provide a user interface include a printer or display screen for visual presentation of output, and a speaker or other sound-generating device for audible presentation of output. Examples of input devices that can be used for the user interface include a keyboard and pointing devices such as a mouse, touchpad, and digitizer. As another example, the computing device may receive input information via voice recognition or in other audible formats.

[0080] Such computing devices can be interconnected via one or more networks in any suitable form, including local area networks (LANs), controller area networks (CLANs), or wide area networks (WANs), such as enterprise networks or the Internet. Such networks can be based on any suitable technology and can operate according to any suitable protocol, and can include wireless networks, wired networks, or fiber optic networks.

[0081] Furthermore, the various methods or processes outlined herein can be encoded as software that can be executed on one or more processors employing any of a variety of operating systems or platforms. Additionally, such software can be written using a variety of suitable programming languages ​​and / or programming or scripting tools, and can also be compiled into executable machine language code or intermediate code that executes on a framework or virtual machine.

[0082] In this regard, the disclosed embodiments may be implemented as a computer-readable storage medium (or multiple computer-readable media) (e.g., a computer memory, one or more floppy disks, compact discs (CDs), optical discs, digital video discs (DVDs), magnetic tape, flash memory, field-programmable gate arrays or other semiconductor devices, or other tangible computer storage media) encoded with one or more programs, which, when executed on one or more computers or other processors, perform methods implementing the various embodiments of the present disclosure discussed herein. As apparent from the foregoing examples, a computer-readable storage medium can retain information for a sufficient time to provide computer-executable instructions in a non-transitory form. Such one or more computer-readable storage media may be transportable, such that one or more programs stored thereon can be loaded onto one or more different computers or other processors to implement the aspects of the present disclosure as described above. As used herein, the term "computer-readable storage medium" includes only non-transitory computer-readable media that can be considered an article of manufacture (i.e., an article of manufacture) or a machine. Alternatively or additionally, the present disclosure may be implemented as a computer-readable medium other than a computer-readable storage medium, such as a propagating signal.

[0083] The terms "program" or "software" are used herein in a general sense to refer to any type of computer code or set of computer-executable instructions that can be used to program a computing device or other processor to implement the various aspects of the invention as discussed above. Furthermore, it should be understood that, according to one aspect of this disclosure, one or more computer programs that perform the methods of this disclosure when executed do not need to reside on a single computer or processor, but can be distributed in a modular manner among multiple different computers or processors to implement the various aspects of this disclosure.

[0084] Computer-executable instructions can take many forms, such as program modules, and can be executed by one or more computers or other devices. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform specific tasks or implement specific abstract data types. Typically, the functionality of program modules can be combined or distributed as needed in various embodiments.

[0085] Furthermore, data structures can be stored in any suitable form on a computer-readable medium. For simplicity, a data structure can be shown as having fields related by their position within the data structure. Such relationships can also be implemented by assigning storage to fields with positions that convey the relationships between fields in a computer-readable medium. However, any suitable mechanism can be used to establish relationships between information in the fields of a data structure, including by using pointers, labels, or other mechanisms that establish relationships between data elements.

[0086] The following discussion involves equations that will use the nomenclature provided in Table 1 below.

[0087]

[0088] Table 1: Terminology

[0089] Figure 8 and Figure 9 Several detailed aspects of the electric motor 820 are shown. Specifically, Figure 8 A schematic diagram of the electric motor 820 is shown. Figure 9 A perspective view of the stator of electric machine 820 is shown. Note that while these figures show specific configurations (e.g., the number of slots, poles, etc.), this disclosure should not be limited thereto. In fact, the electric machine 820 shown in these figures is merely one example of the many electric machines disclosed herein, as will be further demonstrated through the subsequent discussion of other configurations.

[0090] The electric motor 820 shown herein can be used in vehicles such as fully electric vehicles or hybrid electric vehicles. The electric motor 820 can be referred to as an electric motor, traction motor, generator, etc. The electric motor 820 can be a permanent magnet motor, induction motor, etc. In the illustrated embodiment, the electric motor 820 is a three-phase alternating current (AC) machine. The electric motor 820 can be used both as an electric motor to propel the vehicle and as a generator, for example, during regenerative braking. Although described in the context of electrified vehicles, the electric motor 820 can also be used in non-motorized vehicle applications. For example, the electric motor 820 can be used in manufacturing equipment or generators.

[0091] Three-phase electric motors 820 are a common type of electric motor 820. The most basic three-phase brushless electric motor 820 is a 2-pole, 3-slot electric motor 820. Various configurations of electric motors 820 exist with different combinations of poles and slots, such as 4-pole, 3-slot, 4-pole, 6-slot, and 16-pole, 12-slot. As the number of poles and slots increases, a larger torque is obtained, and torque ripple is reduced. In terms of terminology, the number of poles refers to the number of magnetic poles of the rotating rotor, and an electric motor 820 with a pair of north and south poles is called a two-pole electric motor 820. The number of poles can be 2, 4, 6, 8, etc. Phase refers to the number of independent coils used to fix the stator. A three-phase symmetrical electric motor 820 is an electric motor 820 with three independent coils spaced 120 kWh apart. The traction battery can be electrically connected to one or more power electronic modules. The power electronic modules can be electrically connected to the electric motor 820 and can provide the ability to transfer electrical energy bidirectionally between the traction battery and the electric motor 820. For example, a suitable traction battery can provide DC voltage, while the electric motor 820 may require three-phase AC voltage. The power electronics module may include an inverter that converts the DC voltage to three-phase AC voltage according to the needs of the electric motor 820. In regenerative mode, the power electronics module can convert the three-phase AC voltage from the electric motor 820, which acts as a generator, to the DC voltage required by the traction battery.

[0092] The electric machine 820 includes a housing 821 surrounding a stator 822 (or stator core 822) and a rotor 824. The stator 822 is fixed to the housing 821 and includes a cylindrical stator core 822 having an inner diameter 828 (ID 828) and an outer diameter 829 (OD 829) defining an aperture 830. The stator core 822 may be formed from a plurality of stacked laminations. The rotor 824 is supported to rotate within the aperture 830. The rotor 824 may include windings or permanent magnets that interact with the windings of the stator 822 to generate rotation of the rotor 824 when the electric machine 820 is energized. The rotor 824 may be supported on a bearing 826 extending through the housing 821. The rotor 824 is configured to be coupled to a vehicle's drivetrain to output torque for vehicle propulsion or to receive mechanically regenerative energy from vehicle motion.

[0093] The stator core 822 defines circumferentially arranged slots 832 surrounding the stator core 822 and extending outward from the inner diameter 828. The slots 832 may be equidistantly spaced around the circumference. As shown, the stator core 822 defines 24 slots and has 8 poles (or 4 pole pairs). In examples, the stator core 822 may include more or fewer slots and / or poles. For example, the stator core 822 may define 72 slots and have 8 poles (or 4 pole pairs).

[0094] Those skilled in the art will understand that this type of motor has different components, representing parts such as the rotor, stator, and other internal parts. Arrows can indicate the direction of flow, which may correspond to the movement of energy or the current path within the motor. Certain areas highlight the interaction between the motor's magnetic field, current, and mechanical components, providing a visual representation of how these elements work together during motor operation. In comparison, there are two types of motor windings: circular wire windings and hairpin windings. Circular wire windings involve using copper wire wound in a circular shape. Conversely, hairpin windings use pre-formed copper conductors shaped like hairpins. The hairpin design allows for more compact and efficient use of space, which is particularly beneficial for applications requiring higher currents and improved performance. This image highlights the structural differences between the two winding methods, demonstrating how hairpin windings improve the overall efficiency and power handling capacity of the motor.

[0095] Slots 832 are spaced apart by a circumferential distance measured between the centerlines of two adjacent slots. This distance can be used as a unit of distance (hereinafter referred to as a “slot”) in relation to and for measuring other components of the stator 822. The distance unit “slot” is sometimes also used to specify “slot pitch” or “slot span”. Slots 832 are also indicated by the numbers 1 to 24 in the counterclockwise direction, and for convenience, odd numbers of slots are used for marking. These slots can be characterized as odd-numbered slots (i.e., slots 1, 3, 5, etc.) and even-numbered slots (i.e., slots 2, 4, 6, etc.). The odd and even designations are for ease of describing the arrangement of the windings 840, and the structures of odd-numbered and even-numbered slots can be identical.

[0096] The stator core 822 may be formed of laminations and defines a plurality of slots 832. The winding 840 includes an axially extending segment 834 disposed within the slot 832. The axially extending slot 832 surrounds a hole 830 or a central opening 830 of the stator core 822.

[0097] The embodiment shown is a three-phase electric motor 820 with six turns.

[0098] One parameter that can be used to describe the winding arrangement is the number of slots per phase per pole. If each such slot is filled by only one phase of winding, then this is equal to the number of slots per pole in each slot group of winding 840.

[0099] To avoid or minimize recirculating current in winding 840, it is desirable for winding 840 to be electrically balanced, especially for winding 840 with multiple parallel connections. As described above, the hairpin winding 840 configuration can improve the efficiency of electric machines used in vehicles and other applications. Electric machine 820 includes a hairpin winding 840 arranged through slots 832 of stator core 822. The hairpin winding 840 improves efficiency by providing a larger amount of stator conductor to reduce the resistance of winding 840 without encroaching on space reserved for electrical steel and magnetic flux paths. The hairpin winding 840 can be arranged as a wavy winding, wherein winding 840 is braided from one pole to the other in a wavy pattern.

[0100] A particular challenge with the hairpin winding 840 is matching the electric machine design to the desired torque-speed curve. A crucial step in configuring the electric machine 820 is selecting the number of phase turns so that the torque-speed curve covers all desired operating points. For conventional stranded windings made of long wires connected in parallel, the desired number of phase turns is selected by choosing the number of turns per coil, the number of parallel paths, the number of poles, the number of slots per pole, and the number of layers. While this arrangement can also be used with the hairpin winding 840, the limiting factors are very different for pre-formed hairpins, resulting in a smaller range of feasible options. More specifically, while the possible number of poles, slots per pole, and layers can be the same between the two technologies, it is impractical to use the hairpin winding 840 with the same number of turns per coil as in the stranded winding 840. Each hairpin needs to be connected to the next hairpin by soldering, tinning, or other suitable electrical connections, and needs to be bent to a specific shape to make the connection possible. This limits the number and size of conductors that can be in a single slot. Another challenge is creating balanced (e.g., without causing large circulating currents in the loops formed by parallel circuits due to asymmetry) parallel branches within each phase, and with fairly complex connections.

[0101] The hair clips are installed in the stator core 822 by inserting leads into corresponding slots 832. All hair clips can be installed from the same end (e.g., end 836) of the stator core 822, such that all crowns are on one end of the stator (e.g., end 836) and the ends of the leads are on the other end (e.g., end 838). Once installed, the leads of the hair clips are bent away from each other to form twists that connect with the twists of other hair clips. The ends of the corresponding hair clips are joined by connections such as welding. These connections can be arranged in rows. End 836 may be referred to as the crown end, and end 838 may be referred to as the weld end. Each path includes associated hair clips that are joined (e.g., welded) at the ends of the twists to form a continuous conductive conduit between the terminals and the neutral connection. Some hair clips may be too far apart to engage directly, and bridges (e.g., jumpers) may be needed to interconnect these hair clips and complete the path.

[0102] Figure 10 This is a coil phasor diagram of a 36-slot, 6-pole electric motor with full-pitch windings. A coil phasor is a quantity that has amplitude, direction, and time relationships. Phasors are used to represent sinusoidal voltages and currents by plotting them on a rectangular coordinate system. If the phasors are allowed to rotate around the origin, and a graph is constructed from the vertical axis against the time of rotation, then the instantaneous sinusoidal waveform will be represented by the phasors.

[0103] Essentially, a phasor diagram projects a rotating vector onto a horizontal axis to represent its instantaneous value. These diagrams can be plotted to depict any angle or moment in time, and they are specifically designed for sinusoidal AC alternating variables. A phasor diagram can represent multiple fixed sinusoidal quantities at any given moment, with a reference phasor typically plotted along a horizontal axis. All phasors are referenced to a horizontal zero axis and rotated counterclockwise. Phasors preceding the reference phasor are considered leading, while those following are considered lagging. The length of a phasor typically represents the RMS value of the sinusoidal quantity, not its maximum value. In a three-phase equilibrium system, each phasor is displaced by 120 degrees.

[0104] A 36-slot, 6-pole electric motor with full-pitch windings is a type of electric motor that uses a specific configuration of slots and poles to generate rotary motion. The motor has 36 slots that are evenly spaced around the circumference of the motor. These slots are used to hold the motor's windings, which consist of a series of coils.

[0105] The motor also has six poles arranged in a circular pattern around the center of the motor. These poles are made of magnetic material and are used to generate a magnetic field that interacts with the motor's windings to produce rotational motion. The full-pitch winding configuration means that each coil in the windings spans the entire distance between two adjacent poles, which maximizes the motor's winding factor. When current is applied to the motor's windings, it generates a rotating magnetic field that interacts with the rotor's magnetic field, causing the motor to rotate.

[0106] The electric motor 820 may be a three-phase electric motor, wherein hairpin windings 840 are arranged in phases A, B, and C. In the examples of this disclosure, each phase includes multiple individual hairpin conductors arranged in parallel winding paths.

[0107] The proposed winding assignment procedure (or winding pattern or scheme) is represented in the Winding Assignment Table (WDT) below, which allows specific stator slots to be assigned to winding phase portions. The basic rules for determining the WDT are then defined.

[0108] The method is characterized by implementing each parallel path of layer change before phasor change, which uses a singular type of normal hairpin (with y n This is achieved through the winding slot pitch and the welding side. On the other hand, phasor change is achieved through having y n This is achieved using jumpers with a slot pitch of ±k, where k is an integer. Phasor changes occur in either the innermost or outermost layer. A normal hairpin always crosses different layers in different slots, while a jumper always crosses the same layer in different slots. Finally, this contribution is expected to drive the development of more adaptable and versatile hairpin winding designs to meet the needs of high-power, high-speed electric machines.

[0109] The maximum number of parallel paths per phase is n. pp =2p. As shown in the figure, the number of phasors in the electric motor is equal to q. Considering the number of layers n L The influence of the quantity q on the inductance and flux linkage of the conductors, in order to achieve a symmetrical design with no circulating current between parallel paths, the minimum number of conductors for each parallel path can be determined by equation (1).

[0110] )

[0111] The total number of conductors in an electric motor can be written using equation (2).

[0112] (2)

[0113] Therefore, in order to achieve a symmetrical design with no circulating current between parallel paths, the maximum number of parallel paths per phase that can be achieved is 2p, as calculated in equation (3), which is the same as in the case of conventional lap windings.

[0114] (3)

[0115] All the winding layouts discussed above are full-pitch to highlight basic design rules. However, short-pitch windings are widely used in traction motors due to their advantage of reduced armature back magnetomotive force (MMF) harmonics.

[0116] The accompanying figures illustrate the principles of this disclosure for three winding schemes (i.e., Scenarios 1-3) in more detail. The following is a discussion of these scenarios. Scenarios 1 is for a 36-slot 6-pole electric machine with full-pitch and short-pitch windings, where p > q, p = 3, q ​​= 2. Scenarios 2 is for a 54-slot 6-pole electric machine with full-pitch windings, where p = q, p = 3, q ​​= 3. Scenarios 3 is for a 72-slot 6-pole electric machine with full-pitch windings, where p <q,p=3,q=4。

[0117] The principles of this disclosure can be applied to multiphase (e.g., three-phase) windings with or without angular offset. Different winding arrangements are typically suited to different applications. When higher efficiency and lower noise are desired in electric motors, a half-full, half-filled phase band in the stator winding is often desirable. For example, for a stator with two slots per pole per phase, the phase band would be 4-8-4 (four wires in the left slot, eight wires in the middle slot, and four wires in the right slot). This is sometimes referred to as a short-pitch winding or a phase-shifted winding. However, from a design perspective, forming a winding arrangement with a half-full, half-filled phase band can be challenging. For example, all paths of the winding arrangement must be properly connected to advantageous winding characteristics that result in the desired performance characteristics of the electric motor.

[0118] Examples of three common slot - pole combinations are provided, including 36 - slot 6 - pole (p>q, p = 3, q = 2), 54 - slot 6 - pole (p = q, p = 3, q = 3), and 72 - slot 6 - pole (p<q, p = 3, q = 4), to illustrate the winding scheme (or connection rules). As can be observed from these examples, in combination with the rest of the present disclosure, the present disclosure culminates in a unified design paradigm and method together with an alternative hairpin connection methodology. This unity emphasizes that lap and wave windings are essentially the same, and the main difference between them is the way of connecting the winding coils at each end.

[0119] Three cases are considered in detail below in conjunction with the following figures. In Case 1, for an electric machine including 36 slots and 6 poles, p>q, p = 3, q = 2. Case 1 has multiple aspects (e.g., Case 1a - 1d corresponding to the first to fourth implementations respectively), which will be discussed in more detail below. In Case 2, for an electric machine including 54 slots and 6 poles with full - pitch windings, p = q, p = 3, q = 3. In Case 3, for an electric machine including a 72 - slot 6 - pole machine with full - pitch windings, p<q, p = 3, q = 4.

[0120] In all aspects of Case 1, for an electric machine with full - pitch or short - pitch windings, p>q, p = 3, q = 2. In Case 1a, there is a 36 - slot 6 - pole electric machine with full - pitch windings. Here there are 3 pole - pairs (p = 3), such that n pp = 2*3 = 6; the number of phasors is m = 36 / 6 = 6; and the number of phasors per phase is q = 6 / 3 = 2. In Case 1b, similar to Case 1a, there is a 36 - slot 6 - pole electric machine with full - pitch windings but n pp = 2p / 2 = 3. In Case 1c, similar to Case 1a and 1b, there is a 36 - slot 6 - pole electric machine with full - pitch windings but n pp = 2p / 3 = 2. In Case 1d, similar to Case 1a - 1c, there is a 36 - slot 6 - pole electric machine with short - pitch windings to demonstrate that the basic rules from the full - pitch winding design can be easily applied to their short - pitch winding counterparts.

[0121] The various aspects of Case 1 can be seen in Figure 11A 、 Figure 11B and Figure 12 . Figure 11A is a diagram of the winding scheme with a diagonal hairpin winding for a 36 - slot 6 - pole electric machine with full - pitch windings in the first Case 1 implementation. Figure 11B is a diagram of the winding scheme with a diagonal hairpin winding for a 36 - slot 6 - pole electric machine with full - pitch windings. In these diagrams, the solid lines with intermediate arrows represent having yn The normal hairpin of the slot pitch; the dashed line with the middle arrow indicates a slot pitch of (2y p -y n The diagram shows the hairpins on the solder side; and the U-shaped connectors with dashed ends represent jumpers (e.g., on either the outermost or innermost layer). These diagrams show the four hairpin layers (layers 1-4) on the right, the number of slots at the bottom, and the polarity at the top. The number of poles (6 here) corresponds to the number of winding paths (A1-A6), and for clarity, a separate diagram is used for each winding path. Figure 12 It shows that it is aimed at Figure 11A and Figure 11B The diagram shows the pins and jumpers of the electric motor assembled and arranged in a 3D manner within the stator core.

[0122] The dominant rule in this method dictates that each parallel path must traverse all slots for each pole of each phase, including all layers, while maintaining the same number of conductors as other paths, regardless of slot position. Each path can begin from either the innermost or outermost layer. Ultimately, the proposed hairpin winding connection method is unaffected by the number of hairpin layers. Each path achieves a layer change before the phasor change, which, as indicated by the case, is done on either the innermost or outermost layer. A single type of normal hairpin (with y...) is used. n The layer change is achieved by adjusting the winding slot pitch and the weld side. The phasor change is achieved by having y n The jumper is implemented with a slot pitch of ±k, where k is an integer. Phasor changes occur in either the innermost or outermost layer. A normal hairpin has two pins located in different slots on different layers, while a jumper has two pins located in different slots on the same layer. The solder side is characterized by 2*y... p -y n The winding slot pitch is uniformly arranged, where y p It is the interelectrode spacing. Each phase n pp_max The maximum number of parallel paths that can be implemented is 2p.

[0123] Figure 13 A diagonal hairpin winding scheme for an electric machine is shown, the machine comprising 36 slots and 6 poles with full-pitch windings, such that n pp =2p / 2, p>q, p=3, and q=2. The figure shows two distinct winding techniques: the first method involves series connections on the outermost layer, while the second method involves series connections on the innermost layer.

[0124] Furthermore, for case 1, in the implementation of case 1, n pp =2p / 2=3. Based on where n... ppThe first case 1 implementation of =2p can reduce the number of parallel paths by two by concatenating the two parallel paths in the first case 1 implementation. Using the concatenation between path A1 and path A6 as an example, the new path can be implemented in different ways, i.e., two different methods.

[0125] The first method involves implementing a series connection on the outermost layer. Such a winding scheme can utilize the terminal pins located at (layer 1, slot 1) as the starting point for a new path. By... Figure 11A Terminal X1 at (layer 1, slot 8) in (a) and Figure 11B A connection is established between the conductors at (layer 1, slot 14) in path A6 shown in (f), as follows: Figure 11A As in (a), it is necessary to have a winding slot pitch y on the outermost layer. n A shorter jumper wire. Ultimately, the end of this new path appears at the terminal pin located at (Layer 1, Slot 7), as... Figure 13 As shown in (a).

[0126] The second method involves implementing a series connection on the innermost layer. Similarly, the terminal pin located at (layer 1, slot 1) can be used as the starting point for the new path. Figure 11A Terminal X1 (layer 4, slot 19) in (a) and Figure 11B The connection between conductors (layer 4, slot 25) within path A6 in (f) is achieved using a slot pitch y n Established by shorter jumpers, such as Figure 13 As shown in (b). Subsequently, between slot 32 and slot 26, a winding slot pitch y is introduced on the innermost layer. n Another shorter jumper wire. Finally, the end of this new path appears at the terminal pin located at (Layer 1, Slot 8), as... Figure 13 As shown in (b).

[0127] Figure 14 A diagonal hairpin winding scheme for an electric machine is shown, the machine comprising 36 slots and 6 poles, with a full-pitch winding, n pp =2p / 3, such that p>q, p=3, and q=2.

[0128] Furthermore, regarding case 1, in the implementation of the third case 1, n pp =2p / 3=2. Based on where n... ppIn the first case 1 implementation where p=2p, concatenating any three parallel paths in the first case 1 implementation reduces the number of parallel paths by three. For example, paths A1-A3 in the first case 1 implementation can be concatenated with two shorter jumpers to form a new path; similarly, paths A4-A6 in the first case 1 implementation can be concatenated with two shorter jumpers to form another new path. It is worth noting that for p=3 (a 6-pole machine), n pp =2p / 3=2 is an integer, so it is applicable. However, this method is not applicable when p=4 (8-pole machine).

[0129] Figures 15A to 15C An exemplary layout of an electric motor with 36 slots and 6 poles in full-pitch and short-pitch windings is shown, where p > q, p = 3, and q = 2. Figure 16 A diagram showing a diagonal hairpin winding scheme for an electric machine is provided. The machine includes 36 slots and 6 poles, and has short-pitch windings, where npp=2p, p>q, p=3, and q=2.

[0130] Here, the three electrical phases driving this electric machine are represented as {ABC}. To represent the windings of these phases, {A a B b C c} are used, where uppercase letters represent clockwise (CW) windings and lowercase letters represent counter-clockwise (ACW) windings. Each letter will be assigned a different color, with A and a represented in red, B and b in green, and C and c in blue. Therefore, a motor configuration with 6 CW windings (u=2 and z=1) can be represented as ABCABC or more simply as (ABC). 2 Table 2 provides recommended winding patterns in WDT that allow for higher winding coefficients, resulting in higher torque output. The remaining winding patterns listed above can be readily justified using symmetry arguments on a case-by-case basis.

[0131] Further, for case 1, in a short-pitch winding motor, the motor has 36 slots and 6 poles, such that p > q, p = 3, and q = 2. The connection concept is similar for short-pitch windings. The difference is that, due to the short pitch, the slot pitch on the welded side is different from the normal hairpin shape; for a k-slot short-pitch winding, the slot pitch on the welded side is y. n =y p -k, the slot pitch of a normal hairpin winding is y n =y p+k. For a 36-slot, 6-pole machine with a short pitch winding having 1 (k = 1) slot, an example of the proposed diagonal hairpin winding connection is shown, which can achieve the maximum number of parallel paths per phase (i.e., 2p), where only paths A1 and A4 are shown. The connections of paths A2 and A3 are respectively similar to path A1, and the connections of paths A5 and A6 are similar to path A4; the difference is that they start from different pole pairs. Similarly, by connecting two or three paths in series, a smaller number of parallel paths per phase can be easily achieved.

[0132] Figure 17A and Figure 18A shows a different case, i.e., case 2, where the electric machine has 54 slots and 6 poles, where p = q = 3, with a full pitch winding. Similarly, the proposed diagonal hairpin winding connection rules for a 54-slot, 6-pole machine with a full pitch winding can be illustrated. Here, y n = y p = 9 and n pp = 6 or 2p (p = 3, p = 3, q = 3). The connection rules are similar: the slot pitch for both the normal hairpin and the welded side is 9, i.e., y n = y p = 9. For the value q = 3, there are three phasors per phase, and two phasor changes are required. To maintain consistent jumpers, all parallel paths should start from the first phasor, then make phasor changes to the second phasor, and then to the third phasor, or they can start from the third phasor, then make phasor changes to the second phasor, and then to the first phasor.

[0133] Figure 17B and Figure 18B shows yet another different case (case 3) of an electric machine including 72 slots and 6 poles, where p < q, p = 3, q = 4, with a full pitch winding. Here, y n = 6, n pp = 6 or 2p (p < q, p = 3, q = 4). The diagrams in these figures show that the diagonal hairpin winding connection rules can be extended to a 72-slot, 6-pole electric machine with a full pitch winding.

[0134] This figure shows the proposed diagonal hairpin winding configuration for a 54-slot, 6-pole electric machine with a full pitch winding. This figure shows the winding paths (paths A1, A2, A3, A4, A5, A6) of the motor, and each path corresponds to a different phase of the winding. For clarity, the winding paths are color-coded: path A1 is red, path A2 is green, path A4 is blue, path A5 is purple, path A6 is yellow, and other paths are specified by their respective colors.

[0135] These slots are labeled sequentially, and each path includes a jumper wire connecting to a specific slot to ensure proper phase alignment. Jumpers are indicated by dashed lines and shown in different slots, denoted by "Jumper 2 (y)". n +1) "Slots" indicate the distance between connections. This diagram breaks down the winding process into segments, showing how these paths pass through these slots, thus ensuring that the motor phases are wired correctly.

[0136] Winding configuration uses parameter set to y n =6,n pp The proposed "full pitch" design, with p=6, p=3, and q=3, represents a 6-pole, 54-slot machine. This winding method is designed to optimize motor efficiency, phase alignment, and overall performance by utilizing diagonal connections and specific jumper arrangements across slots.

[0137] As stated above, the uniform connection method can be applied to all common ISDW scenarios related to potential applications in traction motors. These scenarios are concisely documented in the WDT shown in Table 2 below. This table does not include ISDW scenarios with more than 96 slots; however, the uniform connection method is still applicable to them.

[0138]

[0139] Table 2: Overview of the possible number of parallel paths per phase for a common ISDW slot-pole combination

[0140] The following discussion provides an overview of applicable slot-pole combinations. Advantageously, the proposed connection method remains unknown regarding the number of hairpin layers. All of this underscores the unity of design principles and theory, including both hairpin and lap winding methods. In the proposed hairpin winding method, the realization of symmetrical multiple three-phase windings is readily apparent, due to the absence of phase shift between the parallel paths of each phase. Due to harmonic current issues, asymmetrical multiple three-phase windings, such as double three-phase windings with a 30-degree offset, are generally not preferred in ISDW motors. If a hairpin-type asymmetrical multiple three-phase winding is indeed required, it can be readily obtained by separating q phasors within each phase band into q phase groups based on a phasor diagram; these q phase groups are then assigned to q three-phase windings; each three-phase winding will occupy only one phasor group, thus the number of three-phase winding groups will be q, and the offset angle between multiple three-phase windings will be the same as the offset angle between phasors within each phase band, which can be calculated in electrical angles as (p*360 / Q).

[0141] Figure 19 This demonstrates the use of the fly wire jumper concept for... Figures 11A to 11D Modification of the unified diagonal hairpin winding in the scheme. Figure 20The diagram illustrates a configuration using the fly wire jumper concept, comprising 36 slots and 6 poles with full-pitch windings (similar to case 1a, where n...). pp A diagram of an electric motor (=2p=6).

[0142] In another aspect of the principles discussed here, there is another modification to the winding scheme. Essentially, while the previous discussion included jumpers with pins located in the same layer, this aspect provides jumpers with pins located in different layers. As mentioned above, a phasor change is required to achieve balance between all parallel paths. In the previous wiring scheme, this relied on jumpers with pins located in the same layer. However, it is worth noting that these two pins have the potential to occupy different layers. It should be noted that those skilled in the art will understand that both aspects can be employed in the example.

[0143] In these cases, we see Case 1 again, where the electric machine has p>q, p=3, q=2 in a 36-slot, 6-pole full-pitch winding. In the first implementation of modified Case 1, n pp =2p=6. It is still feasible if a phasor change from a conductor in (layer 4, slot 19) to a conductor in (layer 1, slot 26) is desired. It requires y... p A jumper with a +1 slot pitch spans across different slots between the innermost and outermost layers; this is defined as a "flying jumper." Afterward, the connection follows the exact same pattern as the connection before the phasor change, and it ends at terminal X1 (layer 4, slot 8), as shown in (a). The 3D model of path A1, as well as the entire model, can be... Figure 20 As seen in (h), all jumpers follow the same pattern and there are no crossovers between them.

[0144] Figure 21 A 3D model of a 96-slot, 8-pole electric motor with short-pitch windings is shown. This motor is a three-phase motor with 8 parallel paths per phase, where n pp =2p=8, making p=q=4. As shown in the figure, the electric machine has 6 hairpin layers. A comprehensive 3D model is provided, featuring red, green, and blue three-phase terminals, yellow jumpers, and standard hairpins specified for gold layer transitions. The terminal positions can be repositioned based on busbar design preferences.

[0145] Figure 22 Examples of various winding paths for a 72-slot, 6-pole electric motor with full-pitch windings are shown. It illustrates three different configurations of the winding paths labeled A1, A2, A3, A4, A5, and A6, with each configuration presented as a separate sub-diagram.

[0146] Part (a) illustrates an embodiment of paths A1, A2, and A3. The figure shows a winding arrangement across four layers of the stator, with paths labeled A1, A2, and A3 arranged sequentially in slots. These paths connect across these layers, and arrows indicate the movement of these winding paths through the slots.

[0147] Part (b) illustrates an embodiment of paths A4, A5, and A6. Similar to part (a), the winding paths (A4, A5, A6) traverse stator slots, with the path order represented as traversing multiple layers. The figure illustrates how these paths are connected to form the windings, where jumpers facilitate connections between different layers.

[0148] Section (c) presents a combined embodiment of all paths (A1, A2, A3, A4, A5, and A6) using an alternative method with jumper wires. This configuration illustrates the complete winding path layout for the entire stator, including all six paths traversing these layers. The use of jumper wires is shown in the figure, providing a more flexible and efficient way to connect different winding paths.

[0149] The overall design uses full-pitch windings with parameters set to nL=4, n pp =2p=6, p=3, and q=3; these parameters were adjusted to optimize motor performance and phase alignment. The diagram illustrates how a jumper method can be applied across all winding paths to achieve proper phase distribution and improved motor efficiency.

[0150] Figure 23 The layout of a winding scheme for a 36-slot, 6-pole electric motor with full-pitch windings is shown. These windings have an integer number of slots / poles / phases (or s). pp For example, a 2-pole, 12-slot machine has spp=2. Integer slot windings have a single-layer winding for full-pitch windings and a double-layer winding when the coil span is reduced compared to the full pitch.

[0151] It should be noted that the terminal pin positions can be arranged in different ways to accommodate preferred phase terminal positions. That is, all terminal pins may be on the outermost layer or all terminal pins may be on the outermost layer. The figure illustrates two embodiments of selectable terminal pin positions for a 36-slot 6-pole motor with full-pitch windings. In the first embodiment shown in section (a), all terminal pins are placed on the outermost layer of the windings. The figure shows the arrangement of the winding paths, where each slot is connected to a corresponding path (A1, A2, A3, etc.), and the terminal pins are indicated by arrows pointing to the outermost layer.

[0152] In the second embodiment shown in section (b), all terminal pins are positioned on the innermost layer of the winding. This configuration also shows the winding path, but now the terminal pins point to the innermost layer. The figure provides a detailed view of how the path passes through the different layers and the positioning of the terminal pins relative to the winding arrangement.

[0153] Both embodiments illustrate winding configurations with parameters set to nL=4, npp=2p=6, p=3, and q=2, ensuring efficient positioning of the terminal pins for proper phase alignment and performance. The figure demonstrates the flexibility of the design, allowing adjustment of the terminal pin positions according to the specific requirements of the motor application.

[0154] Figure 24A and Figure 24B A flowchart of method 2400 according to an example of this disclosure is shown. According to one example, Figure 24A and Figure 24B One or more method boxes can be executed relative to an electric machine (such as those electric machines disclosed elsewhere here).

[0155] like Figure 24A and Figure 24B As shown, method 2400 may include selecting a plurality of hairpin wires to form a plurality of parallel paths, such that each of the plurality of parallel paths spans all slots of each pole of each phase of the motor (block 2402). For example, the electric machine may select a plurality of hairpin wires to form a plurality of parallel paths, such that each of the plurality of parallel paths spans all slots of each pole of each phase of the motor, as described above. Additionally, as... Figure 24A and Figure 24B As shown, method 2400 may include arranging a plurality of hairpin lines such that each of a plurality of parallel paths surrounds all hairpin layers (box 2404). For example, as described above, an electric machine may arrange a plurality of hairpin lines such that each of a plurality of parallel paths surrounds all hairpin layers. Also as Figure 24A and Figure 24B As shown, method 2400 may include maintaining the same number of conductors for each of a plurality of parallel paths, regardless of the slot location (box 2406). For example, as described above, an electric machine can maintain the same number of conductors for each of a plurality of parallel paths regardless of the slot location.

[0156] Method 2300 may include additional implementations, such as any single implementation or any combination of implementations of one or more other processes described below and / or described elsewhere herein. In a first implementation, each of the plurality of parallel paths begins at the innermost or outermost layer of the hairpin layer.

[0157] In the second implementation, either alone or in combination with the first implementation, the hairpin winding is an integrated slot distributed winding.

[0158] In the third implementation, each of the multiple parallel paths, either alone or in combination with the first and second implementations, is configured to implement a layer change before the phasor change.

[0159] In the fourth implementation, layer change is achieved, either alone or in combination with one or more of the first to third implementations, using a single type of normal hairpin with winding slot pitch and weld side.

[0160] In the fifth implementation, either alone or in combination with one or more of the first to fourth implementations, phasor changes are achieved by jumpers having jumper slot pitches equal to the winding slot pitch plus or minus an integer.

[0161] In the sixth implementation, either alone or in combination with one or more of the first to fifth implementations, phasor changes occur at the innermost or outermost layer.

[0162] In the seventh implementation, either alone or in combination with one or more of the first to sixth implementations, phasor changes occur on the innermost and outermost layers.

[0163] It should be noted that, although Figure 24A and Figure 24B An exemplary block diagram of method 2300 is shown, but in some implementations, method 2300 may include more than Figure 24A and Figure 24B The boxes depicted may be more boxes, fewer boxes, different boxes, or boxes arranged differently. Additionally or alternatively, two or more boxes of method 2300 may be executed in parallel.

[0164] The above discussion focuses primarily on the unified diagonal hairpin connection method for Integrated Slot Distributed Winding (ISDW) systems, representing a significant advancement in hairpin winding design. This method is particularly suitable for applications in traction motors where high efficiency, performance, and reliability are essential. The proposed diagonal connection method simplifies the winding process and provides a unified approach applicable across ISDW configurations, ensuring scalability and adaptability. By simplifying the hairpin winding connection process, this disclosure not only reduces manufacturing complexity but also optimizes copper utilization in the winding, thereby improving the overall efficiency of the motor.

[0165] This discussion now builds upon this foundation by introducing a hairpin winding design and implementation method with a high number of parallel paths per phase. The focus of this discussion is a distinctly advanced aspect of hairpin winding design: increasing the number of parallel paths per phase. While uniform diagonal connection methods concentrate on simplifying and unifying the winding process for ISDW configurations, this disclosure takes a further step by introducing a design that allows for a high number of parallel paths, thereby significantly improving motor efficiency, torque, and power density. This design is particularly suitable for high-speed, high-power motors where high DC link voltage limitations can hinder performance.

[0166] These innovations together represent a comprehensive approach to optimizing the design and manufacture of hairpin windings in traction motors. While the unified diagonal connection approach addresses the standardization and flexibility required for various ISDW configurations, the high parallel paths in the per-phase design push the boundaries of possible performance and energy efficiency. This combination of innovations promises not only to streamline the manufacturing process but also to enhance the motor's capabilities, particularly in applications demanding high torque, efficiency, and scalability.

[0167] Figures 25 to 27 Now let's turn to this aspect of the disclosure. Specifically, Figure 25 It shows a configuration with 54 slots, 6 poles, q=p=3, np=6, and y n =9,n w =2 Example hairpin winding. This diagram illustrates the winding configuration of a 54-slot 6-pole motor with 6 parallel paths per phase. It includes a visual representation of the phase A winding layout and details about using jumpers to connect the parallel paths through the various layer groups. Figure 26 It shows a configuration with 54 slots, 6 poles, q=p=3, and n p =6, y n =9,n w =4 Example hairpin winding. This figure shows the winding design of a 54-slot 6-pole motor using a 4-layer hairpin winding. It emphasizes how the winding design can be viewed as two 2-layer hairpin winding designs with jumpers between different layer groups. Figure 27 It shows a configuration with 96 slots, 8 poles, q=p=4, and n p =8, y n =12, n w =2 Example hairpin winding. This figure shows the winding configuration of a 96-slot 8-pole motor with 8 parallel paths per phase. It includes illustrations of the first and second parallel paths starting from the top and bottom layers respectively, as well as the necessary mechanical displacements for phases B and C. Figure 28 It shows a configuration with 96 slots, 8 poles, q=p=4, and n p =8, y n =12, n w=4 Example hairpin winding. The figure shows a 96-slot, 8-pole motor design with 8 parallel paths per phase, combined with 4 layers of hairpin windings. It shows a winding design divided into two 2-layer hairpin winding designs, where jumpers are used for connections between the layers.

[0168] These figures correspond to the examples provided below and illustrate different slot-pole combinations and winding configurations for high-power motors, demonstrating the flexibility and scalability of hairpin winding designs. Note that principles from this aspect can be used in combination with the aforementioned principles or individually (in any combination).

[0169] This disclosure relates to the design of hairpin windings for electric motors, specifically focusing on hairpin winding designs that incorporate a large number of parallel paths for each phase. This design aims to significantly improve motor efficiency, reduce power losses, and provide flexible configurations for a wide range of motor designs. This disclosure is particularly beneficial for high-speed, high-power motors, especially when limited DC link voltage restricts the number of layers and parallel paths in conventional winding designs.

[0170] The hairpin winding design disclosed herein relies on multiple parallel paths within each phase of the motor winding. Each parallel path occupies one slot for each pole, and the slots are positioned such that each parallel path is aligned with a different pole pair. This arrangement ensures that all parallel paths within a phase share the same electromotive force (EMF), ensuring they are electrically aligned and work together effectively to maximize efficiency. The design uses a "layer-group" system, where each group consists of two layers. In a multi-layer hairpin winding configuration, these layers are grouped into two groups, and jumpers are used to connect the different groups. This system provides flexibility and can be applied to motors with various slot-pole combinations, making it suitable for different motor designs.

[0171] The relationship between the number of slots per phase and pole per pole (denoted as q) and the number of pole pairs (denoted as p) must satisfy the relation q = j × p, where j is an integer. This ensures that the number of parallel paths per phase is sufficient to meet the efficiency and power density requirements of the motor. The number of parallel paths per phase can be adjusted based on the number of slots per pole. For example, in a 3-phase system, the maximum number of parallel paths per phase is 2 × q, while in a 6-phase system, the maximum is qqq. However, by connecting some paths in series, fewer parallel paths can be used, thus providing design flexibility.

[0172] The design also incorporates two types of conductors: one with equal lead lengths for most of the windings, and another with unequal lead lengths, the longer lead used for jumper connections between different layer groups. The conductors are pre-shaped and bent into specific forms for easy insertion into the stator slots, and the bending / twist angle remains consistent across both conductor types. This ensures uniformity and consistency during the winding process. For the innermost layer group, only conductors with equal lead lengths are used, while the outer layers require both types of conductors.

[0173] The manufacturing method of hairpin windings involves several key steps. First, conductors are inserted into the slots of the stator. Next, the conductors are twisted and welded at various points to ensure reliable electrical connections between them. For multilayer windings, jumpers with a slot pitch of (yn+1-q) are used to connect different layers, thereby ensuring electrical connections between layers. Finally, connecting rings are welded to the windings to complete the electrical phase alignment of each set of parallel paths.

[0174] This disclosure applies to various slot-pole combinations, such as 24 slots with 4 poles (where q=p=2), 54 slots with 6 poles (where q=p=3), 96 slots with 8 poles (where q=p=4), and 150 slots with 10 poles (where q=p=5). In each configuration, the maximum number of parallel paths per phase is 2×q. If fewer parallel paths are required, some parallel paths can be connected in series, thus providing flexibility for different motor designs and applications.

[0175] Compared to traditional winding systems, this design offers several distinct advantages. One significant advantage is reduced AC losses, achieved through the use of smaller conductors with more parallel paths. This results in improved motor efficiency, particularly at high speeds and power levels. The design also improves the slot fill factor, allowing for higher power density without increasing the motor's physical size. Furthermore, the reduced losses and increased efficiency lead to higher torque generation, enabling the motor to deliver better performance while maintaining or even reducing its size.

[0176] Flexibility is another key advantage of this design. The motor can be easily reconfigured to fit 3-phase or 6-phase systems, and it supports a wide range of slot-pole combinations. This makes the motor suitable for a variety of applications, including those with high-speed, high-power requirements. Furthermore, the reduced number of required winding shapes and simplified manufacturing processes lower production costs and complexity, making the motor more cost-effective to manufacture.

[0177] Overall, the hairpin winding design with highly parallel paths per phase, combined with relevant manufacturing methods, offers substantial improvements over traditional winding systems. It enhances motor efficiency, power density, and flexibility, making it ideal for a wide range of high-speed, high-power motor applications. By reducing losses and increasing torque, this design ensures superior performance while maintaining or reducing motor size. The simplified manufacturing process also reduces cost and complexity, providing a versatile and cost-effective solution for modern motor design.

[0178] This disclosure relates to electric motors, and more specifically, to an advanced hairpin winding design for electric motors that incorporates a large number of parallel paths for each phase, and a manufacturing method that increases efficiency, reduces power losses, and provides flexible motor design configurations. This disclosure is particularly useful for developing high-speed, high-power electric motors, including motors with limited DC link voltages, where conventional winding systems may not meet performance expectations.

[0179] Electric motors require optimized winding configurations that maximize efficiency, minimize losses, and allow for high power density. However, conventional hairpin windings typically use a limited number of parallel paths per phase, which restricts the flexibility and performance of the motor, especially at higher speeds or power outputs. Furthermore, existing winding configurations do not fully utilize available copper, leading to increased copper losses, suboptimal torque, and lower effective heat transfer. Additionally, the manufacturing processes for these windings are often complex and expensive, requiring multiple winding shapes.

[0180] Therefore, there is a great need for an improved hairpin winding design that increases the number of parallel paths per phase, optimizes copper usage, reduces manufacturing costs, and provides greater flexibility in motor design to accommodate a range of motor configurations.

[0181] This disclosure provides an improved hairpin winding design that incorporates a large number of parallel paths per phase, improving motor efficiency, power density, and torque while reducing AC losses. This design is particularly effective for high-speed and high-power motors, where the limited DC link voltage restricts the number of layers and parallel paths that can be used. This design allows for a large number of parallel paths without requiring excessively large conductors, thereby improving motor efficiency without increasing size or cost.

[0182] This disclosure also includes an implementation method that simplifies the manufacturing process by reducing the number of different hairpin shapes required, thereby reducing production costs. Furthermore, the method enables flexible winding configurations, including the ability to easily switch between 3-phase and 6-phase systems, and supports various configurations with different numbers of parallel paths and layer groups.

[0183] The core feature of this disclosure is the use of multiple parallel paths within each phase of the motor winding, with each parallel path occupying one slot per pole. These slots are arranged such that the parallel paths are positioned under different pole pairs, ensuring that these parallel paths in each phase share the same electromotive force (EMF) and maintain electrical alignment. The winding configuration uses a "layer group" system, where each group consists of two layers. In a multi-layer hairpin winding system, these layers are divided into two groups, and jumpers are used to connect the different layer groups. This arrangement provides flexibility, allowing it to be applied to motors with various slot-pole combinations, thus providing versatility in design and application.

[0184] In winding design, the number of slots per phase per pole (denoted by q) should be greater than 1, where q represents the number of slots per phase per pole and p represents the number of pole pairs. The relationship between q and p must satisfy the equation q equals j multiplied by p, where j is an integer. This ensures that the number of parallel paths in each phase is sufficient to achieve the required motor efficiency and power density. By carefully selecting the number of slots per phase per pole, this design ensures optimal performance in different motor configurations.

[0185] The number of parallel paths per phase is determined by the number of slots per pole. In a 3-phase system, the maximum number of parallel paths per phase is twice q, where q is the number of slots per pole. In a 6-phase system, the maximum number of parallel paths is q, although fewer parallel paths can be achieved by connecting some paths in series. For example, in a 3-phase system with two layers of hairpin windings, this design is characterized by two sets of parallel paths: one set with q parallel paths in the forward direction and another set with q parallel paths in the backward direction. The positioning of these paths in the slots ensures that they are electrically aligned and share the same electromotive force (EMF), which is crucial for efficient operation.

[0186] Hairpin winding systems use two types of conductors. The first type consists of conductors with equal lead lengths, which is used in most windings. The second type includes conductors with unequal lead lengths, where the longer leads are used for jumper connections between layers. The innermost layers use only conductors of equal lead length, while the outer layers may require both types of conductors. These conductors are pre-shaped and bent into specific forms for easy insertion into the stator slots. The bending and twist angles of the conductors remain consistent across both types, ensuring uniformity and accuracy throughout the winding process.

[0187] The method for manufacturing hairpin windings involves several key steps. First, conductors are inserted into the stator slots. Then, the conductors are twisted and soldered at different points to ensure proper electrical connections. For multilayer windings, jumpers are used to connect different layers, where specific slot pitches are designed to enable electrical connections between layers. After the windings are inserted and connected, connecting rings are used to connect the windings to the stator, ensuring correct electrical phase alignment for each set of parallel paths.

[0188] This disclosure is applicable to various slot-pole combinations, including configurations such as 24 slots with 4 poles, 54 slots with 6 poles, 96 slots with 8 poles, and 150 slots with 10 poles. In each configuration, the maximum number of parallel paths per phase is twice the number of slots per pole. If fewer parallel paths are required, some paths can be connected in series, allowing flexibility in adapting the design to different motor applications and configurations.

[0189] The hairpin winding design with a high number of parallel paths per phase offers several significant advantages over conventional winding systems. A major advantage is reduced AC losses, achieved by using smaller conductors with a higher number of parallel paths. This reduces losses, leading to increased efficiency, especially at high speeds and power levels. Additionally, the improved slot fill factor allows for higher power density without increasing the physical size of the motor. This design also results in improved torque production, as reduced losses and increased efficiency contribute to higher torque while maintaining or even reducing the motor's size. Furthermore, the design provides flexibility, as the motor can be easily reconfigured to fit 3-phase or 6-phase systems and supports a wide range of slot-pole combinations, making it suitable for various applications. Another benefit is a cost-effective manufacturing process, as the reduced number of required winding shapes and simplified manufacturing steps lower production costs and complexity.

[0190] The hairpin winding design with highly parallel paths in each phase, combined with relevant manufacturing methods, offers substantial improvements over traditional winding systems. It enhances motor efficiency, power density, and flexibility, making it ideal for a wide range of high-speed, high-power motor applications. By reducing losses and increasing torque, this design ensures superior performance while maintaining or reducing motor size. The simplified manufacturing process also reduces cost and complexity, providing a versatile and cost-effective solution for modern motor design.

[0191] Figure 29A series of diagrams illustrate winding configurations for 24-slot, 4-pole motors with different phase designs and layer groupings. The first diagram shows a configuration of a three-phase motor with four parallel paths per phase. It highlights the required number of parallel paths and their connections through the layers. The winding paths for phases A, B, and C are shown, with phase shifts and mechanical degrees clearly indicated. This configuration can be adapted to different phase settings by shifting the electrical phases by 120° and 360° degrees. The second diagram shows an application of a 4-layer hairpin winding design with a 2-layer hairpin winding arrangement, where the windings are divided into different groups. This diagram shows how jumpers connect the layers between different groups and explains the connections from one layer to the next. Additional winding designs provide more flexible and scalable configurations for the phase paths. The final diagram shows a 5-layer hairpin winding design with the same 24-slot, 4-pole configuration, further expanding on how the layers are connected. This diagram shows how jumpers span between different groups, thus providing more complex configurations for higher phase numbers and improving motor efficiency. These examples illustrate various winding strategies for different motor types, demonstrating the flexibility and scalability in motor design. The figure highlights how the number of parallel paths and layers can be adjusted based on the requirements of the motor application.

[0192] The table below lists some slot-pole combinations suitable for motor winding designs, showing the relationship between the number of slots and poles (q, p), the maximum number of parallel paths, and the number of parallel paths applicable to each configuration:

[0193]

[0194] Table 3: Applicable Slot-Pole Combinations

[0195] This table presents slot-pole combinations, where the first column shows the number of slots and poles, the second column defines the values ​​for qqq and ppp, the third column lists the maximum number of parallel paths, and the fourth column provides the applicable number of parallel paths for each configuration. These slot-pole combinations illustrate different winding settings that can be used to design motors with different numbers of parallel paths per phase.

[0196] The following sections provide practical examples of the motor winding design method outlined in the claims, illustrating its application in various motor configurations. These examples highlight how the design method can be implemented in both high-speed and low-speed motors, demonstrating its versatility across highly parallel path configurations for different motor types. By utilizing layered winding configurations with jumpers and implementing forward and backward parallel paths, these examples demonstrate the flexibility and scalability of the design. Furthermore, these examples cover the adaptability of the winding method to both 3-phase and 6-phase systems, emphasizing its potential to optimize motor performance and efficiency in practical applications.

[0197] In Example 1, a method for generating hairpin windings for an electric motor, wherein for any number of hairpin layers, the highest number of parallel paths per phase is equal to twice the number of pole pairs, the electric motor including a stator having a plurality of slots formed therein, through which the hairpin windings can be arranged, the method comprising: selecting a plurality of hairpin wires to form a plurality of parallel paths such that each of the plurality of parallel paths spans all slots of each pole of each phase of the electric motor; arranging the plurality of hairpin wires such that each of the plurality of parallel paths surrounds all hairpin layers; and maintaining the same number of conductors for each of the plurality of parallel paths regardless of slot location.

[0198] In Example 2, as described in Example 1, each of the plurality of parallel paths begins at the innermost or outermost layer of the hairpin layer.

[0199] In Example 3, as described in Example 1 or 2, the hairpin winding is an integrated slot distributed winding.

[0200] In Example 4, the method as described in any one of Examples 1-3, wherein each of the plurality of parallel paths is configured to perform a layer change before a phasor change.

[0201] In Example 5, the method as described in any one of Examples 1-4 is used, wherein a single type of normal hairpin with winding slot pitch and weld side is used to achieve layer variation.

[0202] In Example 6, the method as described in any one of Examples 1-5, wherein the phasor change is achieved by jumpers having jumper slot pitches equal to the winding slot pitch plus or minus an integer.

[0203] In Example 7, the method as described in any one of Examples 1-6, wherein the phasor change occurs on the innermost or outermost layer.

[0204] In Example 8, the method as described in any one of Examples 1-7 is used, wherein the phasor change occurs in the innermost and outermost layers.

[0205] In Example 9, an electric machine includes: a stator comprising a plurality of slots formed therein, through which a winding scheme can be used to arrange the windings; and a hairpin winding arranged through the plurality of slots such that, for any number of hairpin layers, the maximum number of parallel paths per phase is equal to twice the number of pole pairs, each of the plurality of parallel paths traversing all slots of each phase and each pole of the electric machine and surrounding all hairpin layers, while maintaining an equal number of conductors for each of the plurality of parallel paths, regardless of the slot position.

[0206] In Example 10, the electric machine as described in Example 9, wherein each of the plurality of parallel paths begins at the innermost layer or the outermost layer of the hairpin layer, and wherein the hairpin winding is an integrated slot distributed winding.

[0207] In Example 11, the electric machine as described in any one of Examples 9 or 10, layer variation is achieved using a single type of normal hairpin with winding slot pitch and weld side.

[0208] In Example 12, the electric machine as described in any one of Examples 9-11, wherein the phasor change is achieved by jumpers having jumper slot pitch equal to the winding slot pitch plus or minus an integer.

[0209] In Example 13, an electric machine as described in any one of Examples 9-12, wherein phasor changes occur in the innermost and outermost layers.

[0210] In Example 14, there is an electric machine as described in any one of Examples 9-13, wherein the electric machine is an electric motor.

[0211] In Example 15, an electric motor, as described in any one of Examples 9-14, is used, wherein the electric motor is a traction motor for an electric vehicle.

[0212] In Example 16, there is an electric machine as described in any one of Examples 9-15, wherein the electric machine is a generator.

[0213] In Example 17, a system for a stator assembly of an electric motor includes: a plurality of slots radially positioned around an inner cylindrical surface; and a winding scheme for the stator assembly applicable to all integrated slot distributed winding scenarios, the winding scheme including: selecting a plurality of hairpin wires arranged through the slots to form a plurality of parallel paths such that each of the plurality of parallel paths spans all slots of each phase and pole of the electric motor; arranging the plurality of hairpin wires such that each of the plurality of parallel paths surrounds all hairpin layers; and maintaining the same number of conductors for each of the plurality of parallel paths regardless of slot location.

[0214] In Example 18, the system is as described in Example 17, wherein the winding scheme is further applicable to both full-pitch and short-pitch windings.

[0215] In Example 19, the system described in Example 17 or 18 may also be applied to multiple three-phase windings with or without angular offset.

[0216] In Example 20, the system as described in any one of Examples 17-19, wherein the winding scheme includes a fly wire jumper to achieve phasor change, the fly wire jumper including pins located within separate hairpin layers and spanning different slots between the innermost and outermost layers of the hairpin layers.

[0217] In Example 21, a hairpin winding design for an electric motor includes: multiple parallel paths per phase, wherein each parallel path occupies one slot per pole in the stator of the motor; a layered winding structure consisting of two layers, wherein the multi-layered winding is grouped into two layers, and jumpers are used to electrically connect the different layers; for a three-phase motor, the number of parallel paths per phase is 2q, where q is the number of slots per pole; the hairpin winding configuration is scalable, allowing it to be easily adapted to a six-phase motor system by adjusting the number of parallel paths per phase.

[0218] In Example 22, a hairpin winding design as described in Example 21 is used, where each parallel path occupies a slot for each pole and is located under different pole pairs to ensure uniform electrical phase alignment.

[0219] In Example 23, a hairpin winding design as described in Example 21 or 22 is used, wherein the motor is configured as a three-phase motor with q=2, such that the motor has a maximum of 4 parallel paths per phase.

[0220] In Example 24, a hairpin winding design as described in any one of Examples 21-23 is used, wherein the motor is configured for a 6-phase system, wherein the number of parallel paths for each phase is q.

[0221] In Example 25, a hairpin winding design as described in any one of Examples 21-24 is provided, wherein the two layers are connected by jumpers with a slot pitch of (yn+1-q), and the winding configuration allows for a high number of parallel paths to reduce AC losses and improve motor efficiency.

[0222] In Example 26, a hairpin winding design as described in any one of Examples 21-25 is provided, wherein the maximum number of parallel paths for a three-phase motor is 2q, where q is the number of slots per pole.

[0223] In Example 27, a hairpin winding design as described in any one of Examples 21-26 is provided, wherein the hairpin winding includes forward and backward parallel paths, wherein the forward path begins at the top layer and ends at the bottom layer, and the backward path begins at the bottom layer and ends at the top layer.

[0224] In Example 28, a hairpin winding design as described in any one of Examples 21-27 is provided, wherein parallel paths are electrically aligned to maintain the same electromotive force (EMF) for each path within a phase.

[0225] In Example 29, a hairpin winding design as described in any one of Examples 21-28 is provided, wherein the winding design allows for the insertion of both equal lead length conductors and unequal lead length conductors, the unequal lead length conductors being used for jumper connections between layers.

[0226] In Example 30, a method for manufacturing a hairpin winding for an electric motor includes: inserting conductors into slots in the stator of the electric motor; twisting and welding the conductors at various points to form a strong connection; connecting different conductor layer groups using jumpers with a slot pitch of (yn+1-q), wherein each jumper connects the end of one layer group to the beginning of the next layer group; and welding connecting loops to the winding to ensure correct electrical phase alignment for each set of parallel paths.

[0227] In Example 31, the method is described as in Example 30, wherein the twisting and welding steps ensure uniform voltage and current across all parallel paths by controlling the conductor geometry.

[0228] In Example 32, as described in Examples 30 or 31, the jumper wire is pre-shaped to the correct length and angle to simplify the manufacturing process and reduce the risk of manufacturing defects.

[0229] In Example 33, the method as described in any one of Examples 30-32 is performed, wherein the welding connecting ring step is performed to complete the circuit and establish a robust connection for all parallel paths in the winding.

[0230] In Example 34, the method as described in any one of Examples 30-33, wherein the conductor insertion step uses conductors with equal and unequal lead lengths, the unequal lead lengths being used for jumper connections between different layer groups.

[0231] In Example 35, the method as described in any one of Examples 30-34, wherein the winding configuration includes forward and backward parallel paths, the forward path starting from the top layer and ending at the bottom layer, and the backward path starting from the bottom layer and ending at the top layer.

[0232] In Example 36, the method as described in any one of Examples 30-35, wherein the twisting and welding steps include the use of a machine that ensures precise control over the winding, twisting, and welding of these conductors to maintain high efficiency in manufacturing.

[0233] In Example 37, the method as described in any one of Examples 30-36, wherein the jumper wire is soldered to ensure a strong and reliable electrical connection between different layer groups.

[0234] In Example 38, a generally applicable method for assembling hairpin windings of an electric motor having any desired number of parallel pairs includes: using conductors with equal lead lengths for most windings and conductors with unequal lead lengths, wherein the longer leads are used for jumper connections between layers; inserting these conductors into the stator of the motor and twisting them to form a strong electrical connection; using jumper connections with the same slot pitch (yn+1-q) for all configurations, regardless of the parallel paths or the number of layers, ensuring that the winding configuration remains electrically aligned and maximizing the slot fill factor for a particular motor design.

[0235] In Example 39, the generally applicable method as described in Example 38 is used, wherein jumpers are inserted into all motor configurations with a consistent slot pitch of (yn+1-q) to maintain uniform electrical characteristics of the motors.

[0236] In Example 40, the generally applicable method as described in any one of Examples 38 or 39 is used, wherein conductors with unequal lead lengths are used only for connecting the layer group, while the remainder of the winding uses conductors with equal lead lengths.

[0237] In Example 41, a generally applicable method as described in any of Examples 38-40 is used, wherein the winding configuration allows for flexibility, enabling the number of parallel paths to be changed without altering the core assembly method.

[0238] In Example 42, a generally applicable method as described in any one of Examples 38-41 is used, wherein the conductor is pre-shaped and bent to ensure proper insertion into the stator slot, thereby reducing manual labor in the manufacturing process and increasing production efficiency.

[0239] In Example 43, the generally applicable method as described in any one of Examples 38-42 is used, wherein the insertion of the conductor is performed in a stepwise manner, wherein each layer group is inserted sequentially to ensure precise placement.

[0240] In Example 44, a generally applicable method as described in any one of Examples 38-43 is used, wherein the winding configuration comprises multiple layers, each layer being connected by jumpers in a consistent manner across all configurations.

[0241] In Example 45, a generally applicable method as described in any of Examples 38-44 is employed, wherein the conductor insertion step ensures that the conductor is positioned with correct phase alignment to prevent circulating current between parallel paths.

[0242] In Example 46, the method is as generally applicable as any one of Examples 38-45, wherein the winding configuration is suitable for both high-speed and low-speed motors, and the same assembly method is suitable for different operating conditions.

[0243] In Example 47, a generally applicable method as described in any one of Examples 38-46 is used, wherein the number of parallel paths for each phase is determined by the number of slots for each pole, and this configuration is suitable for both high-power and high-efficiency motors.

[0244] In Example 48, a generally applicable method as described in any one of Examples 38-47 is used, wherein the conductors used in the winding are made of rectangular wire to maximize the slot fill factor, which minimizes AC losses and improves efficiency.

[0245] In Example 49, the generally applicable method as described in any one of Examples 38-48 is used, wherein the jumper connection step is performed by precise control of the length and angle of each jumper to ensure uniform electrical characteristics across all parallel paths.

[0246] In Example 50, a generally applicable method as described in any one of Examples 38-49 is used, wherein the winding method reduces the need for specialized equipment, making the manufacturing method more cost-effective and easier to scale.

[0247] In Example 51, a motor winding design method that allows for high parallel paths per phase in both high-speed and low-speed motors includes: multiple parallel paths per phase, wherein each parallel path occupies one slot per pole, and the winding configuration utilizes forward and backward parallel paths; a layered winding configuration with at least two layers, wherein jumpers are used to connect different layers; and a flexible mechanism in the winding design to support scalable configurations for various motor types, such as 3-phase or 6-phase systems.

[0248] In Example 52, the motor winding design method as described in Example 51 uses a unified diagonal hairpin connection method applicable to Integrated Slot Distributed Winding (ISDW) systems to achieve highly parallel path design, thereby ensuring consistent performance across multiple motor configurations.

[0249] In Example 53, a motor winding design method as described in any one of Examples 51 or 52, wherein the flexible mechanism allows easy switching between 3-phase and 6-phase configurations, wherein parallel paths are configured to reduce AC losses and optimize the efficiency of high-speed and low-speed motors.

[0250] In Example 54, the motor winding design method as described in any one of Examples 51-53, wherein jumpers for connecting different layers are configured with a slot pitch of (yn+1-q)(yn+1-q) to maintain uniform electrical characteristics and phase alignment between layers.

[0251] In Example 55, the motor winding design method as described in any one of Examples 51-54, wherein the winding configuration supports a scalable number of parallel paths per phase, and has the ability to connect parallel paths in series in a lower power configuration to reduce the number of paths.

[0252] In Example 56, the motor winding design method as described in any one of Examples 51-55, wherein the conductor system consists of two types of conductors, one having equal lead lengths for most of the winding and the other having unequal lead lengths, with the longer lead used for jumpers connecting the layers.

[0253] In Example 57, a motor winding design method as described in any one of Examples 51-56 is provided, wherein the design allows for the use of both a high number of parallel paths and a diagonal hairpin connection scheme to optimize the slot fill factor and reduce copper losses, thereby enhancing torque / power density and heat transfer.

[0254] In Example 58, a motor winding design method as described in any one of Examples 51-57 is provided, wherein the method is applicable to motors with different slot-pole combinations and the winding design configuration is suitable for different motor sizes and power outputs.

[0255] In Example 59, the motor winding design method as described in any one of Examples 51-58, wherein the flexible mechanism supports customizable winding layers, including options for multi-layer winding configurations, each layer being connected by jumpers to ensure series connection between different groups.

[0256] In Example 60, the motor winding design method as described in any one of Examples 51-59, wherein the winding system minimizes the number of different winding shapes required, reducing manufacturing complexity and cost while improving production efficiency.

[0257] Detailed embodiments of this disclosure are disclosed herein as needed; however, it should be understood that the disclosed embodiments are merely exemplary embodiments of this disclosure and may be implemented in various alternative forms. The drawings are not necessarily drawn to scale; some features may be exaggerated or minimized to show detail of specific components. Therefore, the specific structural and functional details disclosed herein should not be construed as limiting, but merely as a representative basis for teaching those skilled in the art to use the contents of this disclosure in various ways.

[0258] The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit implementations to the precise forms disclosed. Modifications can be made based on the foregoing disclosure, or modifications can be derived from the practice of implementation. As used herein, the term "component" is intended to be interpreted broadly as hardware, firmware, or a combination of hardware and software. It is apparent that the systems and / or methods described herein can be implemented in various forms of hardware, firmware, and / or combinations of hardware and software. The actual dedicated control hardware or software code used to implement these systems and / or methods is not a limitation on the implementation. Therefore, the operation and behavior of the systems and / or methods are described herein without reference to any specific software code—it should be understood that the systems and / or methods can be implemented using software and hardware based on the description herein. As used herein, satisfying a threshold can, depending on the context, mean a value greater than a threshold, greater than or equal to a threshold, less than a threshold, less than or equal to a threshold, equal to a threshold, etc. Although specific combinations of features are listed in the claims and / or disclosed in the specification, these combinations are not intended to limit the disclosure of various implementations. In fact, many of these features can be combined in ways not specifically listed in the claims and / or disclosed in the specification.

[0259] Although each dependent claim listed below may directly depend on only one claim, the disclosure of the various implementations includes each dependent claim in combination with all other claims in the claim set. Elements, actions, or instructions used herein should not be construed as critical or essential unless explicitly described as such. Furthermore, as used herein, the articles “a” and “an” are intended to include one or more items and are used interchangeably with “one or more.” Furthermore, as used herein, the article “the” is intended to include one or more items associated with the article “the” and is used interchangeably with “the one or more.” Furthermore, as used herein, the term “group” is intended to include one or more items (e.g., related items, unrelated items, combinations of related and unrelated items, etc.) and is used interchangeably with “one or more.” Where only one item is intended to be used, the phrase “only one” or similar language is used. Furthermore, as used herein, the terms “has,” “have,” “having,” or similar terms are intended to be open-ended terms. Additionally, the phrase “based on” is intended to mean “at least partially based on,” unless otherwise explicitly stated. Furthermore, as used herein, the term “or,” when used in series, is intended to be inclusive and may be used interchangeably with “and / or” unless otherwise explicitly stated (e.g., if used in combination with “any” or “only one of them”).

Claims

1. A method for forming a uniform diagonal hairpin winding for an electric machine, comprising: Multiple rectangular conductors are inserted into a stator core with multiple slots; The conductors are arranged in multiple layers within the slots such that each parallel path spans all slots for each pole of each phase having an equal number of conductors; The number of parallel paths (npp) formed per phase is equal to twice the number of pole pairs (2p), where p is the number of pole pairs; A normal hairpin with winding slot pitch (yn) and uniform weld side arrangement is used to perform layer changes before phasor changes, thereby maintaining conductor uniformity across all layers. A phasor change is performed on at least one of the innermost or outermost layers using jumper conductors with a pitch of (yn±k), where k is an integer, including fly wire jumpers connecting different layers; as well as Rows of conductors with uniform orientation are welded to the stator end face; The method described therein minimizes the number of unique pin types required, achieves maximum parallel path count without being constrained by the number of hairpin layers, and thereby reduces circulating current and harmonics.

2. The method of claim 1, wherein two or more of the parallel paths are selectively connected in series to achieve npp=2p / 2 or npp=2p / 3, and wherein the series connection is implemented on at least one of the innermost or outermost layers using jumpers with slot pitch yn, thereby achieving torque-speed flexibility while reducing conductor length and copper loss.

3. The method of claim 1, wherein the jumper wire provides an interconnect between the innermost and outermost layers, thereby reducing the number of jumper types, minimizing inventory complexity, and simplifying manufacturing logistics.

4. The method of claim 1, wherein each parallel path begins from a common phasor and sequentially traverses other phasor transitions, thereby suppressing torque ripples and ensuring balanced phase currents.

5. A method for manufacturing a high parallel path hairpin winding for an electric motor, comprising: The winding is designed to include twice the number of parallel paths per phase (npp) equal to the number of pole pairs (2p), where p is the number of pole pairs; Multiple rectangular conductors are arranged in layers in the stator slots such that each parallel path spans all slots of each pole of each phase with an equal number of conductors. Normal hairpins using winding slot pitch (yn) perform layer changes before phasor changes, thereby maintaining current symmetry on all paths; A phasor change is performed on at least one of the innermost or outermost layers using jumper conductors with a pitch of (yn±k), where k is an integer, including fly wire jumpers connecting different layers; as well as The winding is completed by welding rows of evenly oriented conductors to the stator end face; The aforementioned arrangement reduces conductor length and resistance, suppresses circulating current and harmonics, and thereby enhances motor efficiency, increases power density, reduces power loss, and simplifies automated manufacturing.

6. The method of claim 5, wherein the winding is further configured for short-pitch and full-pitch operation across slot-pole combinations, the slot-pole combinations comprising at least a 36-slot 6-pole motor, a 54-slot 6-pole motor, and a 72-slot 6-pole motor, and wherein each parallel path terminates at a bus located at the stator end for simplified inverter integration.

7. The method of claim 5, wherein the welding arrangement comprises welds positioned in a uniform row with a consistent orientation, and wherein such arrangement facilitates automated welding, reduces misalignment, lowers costs, and increases manufacturing yield.

8. The method of claim 5, wherein the rectangular conductor is coated with an insulating varnish comprising polyimide or polyesterimide, and wherein a portion of the varnish is selectively removed at the soldering location to reduce resistance and ensure a high-quality solder joint, thereby improving thermal management and winding durability.

9. An electric machine comprising a stator core, a plurality of rectangular conductors arranged in multiple layers within stator slots, and a hairpin winding formed by the method according to any one of claims 1 to 8.

10. The electric machine of claim 9, wherein the electric machine is part of a mobility application including at least one of a traction motor or an inverter.

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