A permanent magnet motor stator multi-phase winding

Abstract

The present invention discloses a multi-phase winding of a permanent magnet motor stator. In the multi-phase winding, each phase winding is formed by connecting one coil or multiple coils, each coil includes a double-layer conductor element at the head end and a single-layer conductor element at the end and a plurality of intermediate double-layer conductor elements arranged between the two. The upper (or lower) conductors of all double-layer conductor elements are connected in sequence through the end conductors, and after being connected to the end element, the lower (or upper) conductors of all double-layer conductor elements are connected in reverse order. Each element corresponds to a stator slot, and there is an insulating medium between the upper and lower conductors of the double-layer conductor elements located in the same stator slot, and the number of stator slots spanned by adjacent elements in the same coil is the same. The winding of the present invention has the advantages of small leakage reactance, small conductive resistance, small heat loss, etc., which is of great significance to improving the power factor, efficiency and power density of the motor. The coil topology can be extended and expanded according to the number of stator slots, and the present invention is particularly suitable for multi-pole and multi-phase permanent magnet motors.

Description

Technical Field

[0001] The invention relates to the field of electric motors or generators, and in particular to a multi-phase stator winding of a permanent magnet motor. Background Art

[0002] Nowadays, in advanced industrial and energy fields, the motors or generators used are expected to be smaller, lighter and more efficient, which means that the motors are required to have higher power density (the rated power output on the motor shaft per unit volume) or torque density (the rated torque output on the motor shaft per unit volume). The advantages of permanent magnet motors over asynchronous motors in efficiency and power density have become a development trend in the industrial and transportation energy fields.

[0003] The magnetic flux of a traditional permanent magnet motor is distributed radially. The teeth that provide the stator magnetic flux path and the slots that place the armature winding conductors are located in the same plane. For a certain stator inner diameter size (taking the inner rotor structure as an example), the width of the stator slot and the width of the tooth restrict each other. If a larger current needs to flow, a larger coil cross-sectional space is required, the width of the tooth is affected, and the magnetic flux passing through the tooth will decrease, and vice versa. If the tooth width and slot width increase at the same time, the diameter of the motor will increase, reducing the torque density of the motor. The transverse flux motor proposed in the past decade can theoretically achieve a higher torque density, but its structure is complex. At present, the power factor of the transverse flux motor is generally low, resulting in an increase in the capacity of the drive system and an increase in cost.

[0004] On the other hand, the size of the motor is closely related to the heat loss of the motor. The motor loss is composed of core loss, copper loss of the armature winding, etc. Among them, the loss heat generated by the current flowing through the conductor and the heat dissipation conditions of the motor have an important influence on the power density of the motor. When the cooling method and insulation are determined, the current density of the motor winding conductor is limited by the size of the heat dissipation part of the motor. Generally, the smaller the size of the motor and the higher the slot fill rate, the worse the heat dissipation capacity of the motor, resulting in an increase in the steady-state temperature of the motor and a decrease in the output peak power. Reducing the loss of the motor can increase the power density of the motor and improve resource utilization.

[0005] Therefore, developing a winding (coil) technology that helps reduce losses and improve motor power factor, efficiency and other major performance is of great practical significance for achieving miniaturization of electromechanical equipment, and will have a huge driving effect on the development of the industrial and energy fields. Summary of the invention

[0006] The purpose of the present invention is to provide a permanent magnet motor stator multi-phase winding to address the deficiencies of the prior art. The stator winding coil adopts a special topological structure to reduce motor losses and improve motor energy conversion efficiency.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A multi-phase stator winding of a permanent magnet motor, each phase is formed by connecting one coil or multiple coils, wherein:

[0009] Each of the coils includes a head end element and a tail end element, wherein the head end element is a double-layer conductor element, and the tail end element is a single-layer conductor element, and a plurality of double-layer conductor elements are connected between the head end element and the tail end element; the double-layer conductor element includes two layers of conductors, each of which is wrapped with an insulating medium, and an interlayer insulating medium can be arranged between the upper and lower layers of the conductors wrapped with insulation as needed, and the single-layer conductor element is composed of a single-layer conductor and an outer insulating medium material covering it.

[0010] Starting from the head end element, the upper conductors of all double-layer conductor elements are connected in sequence and connected to one end (incoming line) of the terminal element, and the other end (outgoing line) of the terminal element is connected to the lower conductor of the double-layer conductor element, and the lower conductors of all double-layer conductor elements are connected in sequence until the head end element is reached, so that the upper and lower conductors of the head end element correspond to the input and output ends of the coil respectively; or, starting from the head end element, the lower conductors of all double-layer conductor elements are connected in sequence and connected to the incoming line end of the terminal element, and the outgoing line of the other end of the terminal element is connected to the upper conductor of the double-layer conductor element, and the upper conductors of all double-layer conductor elements are connected in sequence until the head end element is reached, so that the lower and upper conductors of the head end element correspond to the input and output ends of the coil respectively.

[0011] Each element constituting one coil corresponds to a stator slot, and the number of stator slots spanned by any two adjacent elements is the same, and the adjacent elements correspond to different magnetic poles of the permanent magnet motor rotor.

[0012] In a preferred technical solution, the multi-phase is greater than or equal to 3 phases.

[0013] In a preferred technical solution, each phase is formed by connecting a plurality of coils in series or in parallel.

[0014] In a preferred technical solution, in the double-layer conductor element, each layer of conductor (ie, the upper conductor or the lower conductor) is composed of a single conductor wrapped with an insulating material.

[0015] In a preferred technical solution, in the double-layer conductor element, each layer of conductor (ie, the upper conductor or the lower conductor) is composed of two conductors in parallel and coated with insulating materials.

[0016] In a preferred technical solution, in the single-layer conductor element, the single-layer conductor is composed of a single conductor wrapped with an insulating dielectric material, or the single-layer conductor is composed of two conductors wrapped with insulating materials connected in parallel.

[0017] In the preferred technical solution, the conductor wrapped with insulating material can be an electromagnetic wire (i.e., enameled wire) commonly used in general motors, which is composed of a material with high conductivity such as copper, aluminum, or alloy and an outer insulating film. It can be an outer insulating conductor with a rectangular cross-section, or it can be an outer insulating conductor with a specially designed cross-sectional shape.

[0018] In a preferred technical solution, the double-layer conductor element may be provided with an interlayer insulating medium between the upper and lower layers of conductors covered with insulation as required.

[0019] In the preferred technical solution, the shape of each element can adapt to different slot shapes. The slot shape of the stator can be a straight slot (with a rectangular cross section) with the slot centerline passing through the center point of the motor, or a non-straight slot (with a parallelogram cross section) with the slot centerline deviating from the center point of the motor.

[0020] In the present invention, in each coil constituting each phase winding, each element corresponds to a stator slot, and current is introduced from one layer (upper or lower layer) of the double-layer conductor element as the head end element, first passing through the upper layer (or lower layer) conductor of all the double-layer conductor elements in the middle in turn, reaching the single-layer conductor element as the end element, and then passing through the lower layer (or upper layer) conductor of all the double-layer conductor elements in the middle in reverse order, and finally the current flows out from the other layer (lower layer or upper layer) of the double-layer conductor element as the head end element. It can be seen that the starting conductor of each coil and the end conductor of the outgoing line are two layers of conductor elements of the head end element, which are located in the same slot corresponding to the head end element. In this way, the winding coils are arranged symmetrically, which is very convenient for placing multiple coils in the slot, which is conducive to improving the utilization rate of the slot.

[0021] Since the distance between the coil end conductors on both sides of the stator is short, the winding leakage reactance is small; moreover, in the stator slot where each double-layer conductor element is located, the current direction flowing through the upper and lower conductors is consistent, and the conductors in each layer are in series relationship, and the conductors in each layer are in series relationship. Therefore, the coil voltage is related to the number of element sides of the coil, which facilitates voltage adjustment in the design; in addition, in each coil that makes up the multi-phase winding, the number of stator slots spanned by each pair of adjacent elements is the same, so the distance between adjacent elements in the coil (for the spacing of the stator slots) is related to the number of phases of the motor, so that the topological structure of the coil can be extended according to the number of stator slots to form the required number of poles, which is particularly suitable for multi-pole and multi-phase permanent magnet motor coils.

[0022] Moreover, the elements in each coil, whether double-layer conductor elements or single-layer conductor elements, are coated with outer insulating material outside the conductor, and one or both sides of the winding conductor are directly in contact with both sides of the slot through insulation, which greatly improves the heat dissipation capacity of the winding conductor.

[0023] In the coil structure proposed by the present invention, the conductors in the same slot are insulated from each other, and parasitic capacitance is formed between the upper and lower conductors. Since the distance between the upper and lower conductors is short and the electric field between the upper and lower layers is large, the corresponding capacitance can compensate for the inductance of the winding conductor and improve the power factor of the generator.

[0024] Therefore, the motor stator winding and stator assembly of the present invention have small resistance loss and leakage reactance at the coil end; the single-layer conductor is composed of a single conductor or two conductors connected in parallel, which has a good heat dissipation effect; the capacitance between the upper and lower layers of the coil can compensate for the leakage reactance, which is beneficial to improving the motor power factor; the coil can also make full use of the electric field energy to improve the motor energy conversion rate.

[0025] Compared with the prior art, the present invention has the following obvious outstanding substantive features and significant technical progress:

[0026] (1) The voltage is easy to adjust. The winding of the present invention is easier to adjust the relationship between voltage and magnetic flux than the winding with integer turns. The winding (coil) of the present invention can be easily matched with a multi-pole motor and is particularly suitable for use as a stator component of a multi-pole multi-phase motor.

[0027] (2) The length of the end wire is small. The end size of the winding (coil) of the present invention is small, which saves materials, reduces copper loss, and reduces motor leakage reactance; the winding adopts upper and lower layers, each layer has one or two wires, that is, the two sides of the conductor are directly in contact with the stator slot, the heat dissipation area is large, and the heat dissipation effect is good;

[0028] (3) The winding coil of the present invention has a large capacitance effect, which is beneficial for compensating the motor winding inductance and improving the motor power factor.

[0029] (4) The winding (coil) of the present invention has the characteristics of small leakage reactance, small conductive loss, high power factor and the advantage of electric field participating in energy conversion, which is of great significance to improving the power (torque) density and efficiency of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of the topological structure of a single coil constituting the winding of the present invention.

[0031] Figure 2 is a schematic diagram of the structure of a double-layer conductor element, where Figure 2 a and Figure 2 b are schematic diagrams of two different structures of double-layer conductor elements.

[0032] Figure 3The figure is a schematic diagram of the connection of the components in a single coil constituting the winding of the present invention.

[0033] Figure 4 The figure is a schematic diagram of the relative positions of the components in a single coil constituting the winding of the present invention and the rotor magnetic poles.

[0034] Figure 5 The schematic diagram of the coils forming the phase winding by connecting them in series or in parallel (where Figure 5 a is the winding composed of coils connected in series, Figure 5 b is the coils connected in parallel to form a winding).

[0035] Figure 6 The figure is a schematic diagram of the winding connection method taking a three-phase motor as an example.

[0036] Figure 7 Diagram showing the arrangement of the upper and lower conductors of the coil elements in the slots. DETAILED DESCRIPTION

[0037] Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings and examples, so as to more clearly understand the technical content of the present invention. It should be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0038] Embodiment 1:

[0039] See also Figure 1 to Figure 7 The stator multi-phase winding of the permanent magnet motor is composed of one coil or multiple coils connected in each phase.

[0040] Each of the coils comprises a head end element and a terminal element, wherein the head end element is a double-layer conductor element, and the terminal element is a single-layer conductor element, and a plurality of double-layer conductor elements are connected between the head end element and the terminal element; the double-layer conductor element comprises upper and lower layers of conductors each wrapped with an insulating medium, and an interlayer insulating medium can be arranged between the upper and lower layers of the conductors wrapped with insulation as required, and the single-layer conductor element comprises a single-layer conductor and an outer insulating medium material wrapped therewith;

[0041] Starting from the head end element, the upper conductors of all double-layer conductor elements are connected in sequence and connected to one end of the terminal element, the incoming line; the other end of the terminal element, the outgoing line, is connected to the lower conductor of the double-layer conductor element; the lower conductors of all double-layer conductor elements are connected in sequence until the head end element ends, so that the upper and lower conductors of the head end element correspond to the input and output ends of the coil respectively; or, starting from the head end element, the lower conductors of all double-layer conductor elements are connected in sequence and connected to the incoming line end of the terminal element, the outgoing line of the other end of the terminal element is connected to the upper conductor of the double-layer conductor element, and the upper conductors of all double-layer conductor elements are connected in sequence until the head end element ends, so that the lower and upper conductors of the head end element correspond to the input and output ends of the coil respectively;

[0042] Each element constituting one coil corresponds to a stator slot, and the number of stator slots spanned by any two adjacent elements is the same, and the adjacent elements correspond to different magnetic poles of the permanent magnet motor rotor.

[0043] Embodiment 2:

[0044] This embodiment is basically the same as the first embodiment, with the following special features:

[0045] The multi-phase is greater than or equal to 3 phases.

[0046] Each phase is composed of multiple coils connected in series or in parallel.

[0047] In the double-layer conductor element, each layer of conductor is composed of a single conductor wrapped with an insulating dielectric material.

[0048] In the double-layer conductor element, each layer of conductor, namely the upper layer conductor or the lower layer conductor, is composed of a single conductor or two parallel conductors wrapped with insulating materials.

[0049] In the single-layer conductor element terminal element, the single-layer conductor is composed of a single conductor wrapped with an insulating material.

[0050] In the single-layer conductor element, the single-layer conductor may be composed of two conductors wrapped with insulating materials and connected in parallel.

[0051] The double-layer conductor element may be provided with an interlayer insulating dielectric material between the upper and lower layers of conductors covered with insulation as required.

[0052] Embodiment three:

[0053] In this embodiment, a permanent magnet motor stator multi-phase winding, each phase is formed by connecting one coil or multiple coils, wherein each coil is as follows: Figure 1As shown, it includes a head end element 1 and a terminal element 3, and a plurality of intermediate elements 2 are connected between the head end element 1 and the terminal element 3. The head end element 1 and the intermediate element 2 are both double-layer conductor elements, and the terminal element 3 is a single-layer conductor element.

[0054] The double-layer conductor element includes a conductor inner core and an outer insulating material covering the inner core, and the inner core is composed of two layers of conductors, an upper and a lower layer, and an interlayer insulating dielectric material arranged between the upper and lower layers. As an example, Figure 2 a and Figure 2 b shows two different structural schematic diagrams of double-layer conductor elements.

[0055] Figure 2 In a, the double-layer conductor element includes a conductor core and an outer insulating material 214 covering the conductor core. The conductor core is composed of a single upper conductor 211 covered with an insulating material, a single lower conductor 212 covered with an insulating material, and an interlayer insulating dielectric material 213 arranged between the upper conductor 211 and the lower conductor 212.

[0056] Figure 2 In b, the double-layer conductor element includes a conductor core and an outer insulating material 224 covering the conductor core. The conductor core is composed of two upper conductors 221 wrapped with insulating materials in parallel, two lower conductors 222 wrapped with insulating materials in parallel, and an interlayer insulating dielectric material 223 arranged between the upper conductors 221 and the lower conductors 222.

[0057] The single-layer conductor element is composed of a single-layer conductor and an outer insulating material covering the single-layer conductor. The single-layer conductor can be composed of a single conductor with an outer insulating material, or the single-layer conductor can be composed of two conductors with an outer insulating material connected in parallel.

[0058] Therefore, in each double-layer or single-layer conductor element, only one or two conductors are arranged and distributed in the slot along the circumferential direction, that is, one or both sides of the winding conductor are directly in contact with both sides of the slot through insulation, which greatly improves the heat dissipation capacity of the winding conductor.

[0059] Moreover, no matter it is a double-layer conductor element or a single-layer conductor element, the conductor is coated with an outer insulating material to ensure that the conductors in the same slot are insulated from each other, and a parasitic capacitance and electric field are formed between the upper and lower conductors. Since the distance between the upper and lower conductors is close and the electric field between the upper and lower layers is large, the corresponding capacitance can compensate for the inductance of the winding conductor and improve the power factor of the generator.

[0060] The connection method of the first end element 1, the middle element 2 and the end element 3 in a single coil is as follows: Figure 1 and Figure 3 As shown, the specific combination Figure 1 and Figure 3 The instructions are as follows:

[0061] Starting from the head-end element 1, the upper conductors in all double-layer conductor elements (i.e., the head-end element 1 and all the intermediate elements 2) are connected in sequence, and the incoming lines are connected to the single-layer conductor element (i.e., the end element 3). At the same time, the outgoing lines of the single-layer conductor element are connected to the lower conductors in the adjacent double-layer conductor element, and the lower conductors in all the double-layer conductor elements are connected in reverse order, and finally the lower conductor of the head-end element 1 is connected. That is, the starting conductor and the outgoing end conductor of each coil are two-layer conductor elements of the head-end element 1, and the upper and lower conductors in the head-end element 1 correspond to the input and output ends of the coil respectively;

[0062] Of course, the lower conductor in the head-end element 1 can also be set to correspond to the coil input end, and the upper conductor to correspond to the coil output end, that is: starting from the head-end element 1, the lower conductors in all double-layer conductor elements (that is, the head-end element 1 and all intermediate elements 2) are connected in sequence, and the incoming line is connected to the single-layer conductor element (that is, the end element 3). At the same time, the outgoing line of the single-layer conductor element is connected to the upper conductor in the adjacent double-layer conductor element, and the upper conductors in all double-layer conductor elements are connected in reverse order, and finally connected to the upper conductor of the head-end element 1.

[0063] As an implementation example, Figure 3 A schematic diagram of the layout of a single coil (such as phase A coil) of a three-phase motor is given. Figure 3 , 31 is the stator tooth, 32 is the stator slot, 33 is the upper side of the head end element, 34 is the upper side of the middle element, 35 is the terminal element (single-layer conductor), 36 is the lower side of the middle element; 37 is the lower side of the head end element. In the figure, (A+) represents the lead-out terminal of the upper side of the head end element of the A-phase coil, and (A-) represents the lead-out terminal of the lower side of the head end element of the A-phase coil.

[0064] When in use, current is passed through the upper (or lower) conductor of the head-end element 1 (this is the input end I of the coil), passes through the upper (or lower) conductors of all the intermediate elements 2 in turn, reaches the end element 3 (single-layer conductor), and then passes through the lower (or upper) conductors of all the intermediate elements 2 in reverse order, and finally the current flows out from the lower (or upper) conductor of the head-end element 1 (this is the output end O of the coil). It can be found that: in a coil, the direction of the current flowing through the upper and lower conductors of each element located in the same stator slot is consistent, and the conductors of each layer are in series relationship. The coil voltage is related to the number of element sides of the coil, which is very convenient to adjust the voltage as needed; moreover, the starting conductor and the end conductor of each coil are located in the same slot corresponding to the head-end element 1, the distance between the coil end conductors on both sides of the stator is short, and the winding leakage reactance is small.

[0065] In addition, each element constituting a single coil corresponds to a stator slot, and the number of stator slots spanned by two adjacent elements is the same (the spacing between the elements is equal). Therefore, the distance between adjacent elements in the coil (for the spacing of the stator slots) is related to and determined by the number of phases of the motor. In this way, the topological structure of the coil can be extended according to the number of stator slots to form the required number of poles, which is particularly suitable for multi-stage multi-phase permanent magnet motor coils. The multi-phase here especially refers to more than or equal to 3 phases.

[0066] Moreover, the adjacent elements correspond to different magnetic poles of the rotor, such as Figure 4 As shown. For a permanent magnet motor, magnetic steel is sequentially assembled on the permanent magnet rotor to form a distribution of N, S, N, S. In the magnetic steel gap area, the magnetic field in the air gap appears as an alternating magnetic field (from the N direction magnetic field to the S direction magnetic field). In the figure, 41 represents the head end element (double-layer conductor), 42 represents the output end of the head end element (upper conductor), 43 represents the input end of the head end element (lower conductor), 44 represents the end conductor, 45 represents the terminal element (single-layer conductor), and 46 represents the rotor permanent magnet.

[0067] A plurality of the above coils are connected in series or in parallel to form a phase winding. For example, three coils form a phase winding. Figure 5 a and Figure 5 As shown in b. Figure 5 In a, a plurality of the above coils are connected in series to form a phase winding, and the A-phase winding, the B-phase winding, and the C-phase winding constitute the stator winding of the three-phase motor. Figure 5 b, multiple coils are connected in parallel to form a phase winding, and the stator winding of the three-phase motor is formed by the A phase winding, the B phase winding, and the C phase winding. In the figure, 511-513 are the coils connected in series or in parallel in the A phase winding, 514-516 are the coils connected in series or in parallel in the B phase winding, and 517-519 are the coils connected in series or in parallel in the C phase winding.

[0068] The above multi-phase winding is assembled on the stator as a stator winding to form a corresponding stator assembly.

[0069] As an example, Figure 6 A schematic diagram of the winding (single coil) arrangement is given taking a three-phase motor as an example. Figure 6 In the example, the winding is unfolded into a plane, and the adjacent elements of the same coil are separated by 3 slots. Figure 1 The conductors in the coil are arranged and connected in a manner to form a double-layer coil. 601 is the same stator tooth, and 602 is the same stator slot.

[0070] Figure 6 , 611 is the upper side of the A-phase winding (coil) head end element; 612 is the lower side of the A-phase winding (coil) head end element; 613 is the A-phase winding (coil) end element side (single layer), and 613 refers to the same conductor.

[0071] 621 is the upper layer side of the B-phase winding (coil) head end component, 622 is the lower layer side of the B-phase winding (coil) head end component, 623 is the B-phase winding (coil) end component side (single layer), and 623 refers to the same conductor.

[0072] 631 is the upper layer side of the C-phase winding (coil) head end component, 632 is the lower layer side of the C-phase winding (coil) head end component, 633 is the C-phase winding (coil) end component side (single layer), and 633 refers to the same conductor.

[0073] It can be seen that the voltage between the beginning and the end of each coil is related to the voltage of each conductor of the coil, which is the voltage of the series sum of each conductor.

[0074] Assume that the entire coil has Zk elements, that is, corresponding to Zk slots. When the motor rotates, the potential generated by each conductor (the upper or lower conductor in the slot) is Eb, and the total potential of a coil is Ek, Ek = (2×Zk-1)Eb

[0075] Assume that a phase winding of a motor is composed of Np coils in series and Nb coils in parallel, and the total potential Eph of this phase winding is: Eph=Np×Ek.

[0076] Figure 7 The upper and lower conductors of the coil are arranged in the slots. As an example, a single conductor is wound into a coil. Figure 7 In the figure, 71 is the upper side conductor (including outer insulation), 72 is the lower side conductor (including outer insulation), 73 is the interlayer insulation material; and 74 is the outer insulation of the component. Figure 7 a is the conductor arrangement in the stator slot when the slot is straight and the conductor is rectangular; Figure 7 b is the conductor arrangement in the stator parallelogram slot when the conductor is rectangular. Figure 7 c is the conductor arrangement in the stator slot when the stator slot is straight and the conductor is circular. Figure 7 The diagram shows the conductor arrangement in the stator parallelogram slot when the conductor is circular.

[0077] Those skilled in the art can understand that in the above-mentioned double-layer conductor element, the conductor core can also adopt other structures, for example, the conductor core is composed of a single upper conductor wrapped with insulating material, two lower conductors wrapped with insulating material in parallel, and an interlayer insulating dielectric material arranged between the upper conductor and the lower conductor; or the conductor core is composed of two upper conductors wrapped with insulating material in parallel, a single lower conductor wrapped with insulating material, and an interlayer insulating dielectric material arranged between the upper conductor and the lower conductor. Although there are inconveniences in production, it can still be regarded as one of the implementation methods.

[0078] Those skilled in the art can understand that the conductor covered with insulating material can be a commonly used electromagnetic wire (i.e., enameled wire) for general motors, which is composed of a material with high conductivity such as copper, aluminum, or alloy and an outer insulating film; it can also be a conductor with a rectangular cross-section (outer insulating material), or a conductor with outer insulation of a specially designed cross-sectional shape. Of course, the outer insulating material and interlayer insulation should meet sufficient insulation withstand voltage and corona resistance performance.

[0079] Moreover, the components in each coil, whether double-layer conductor components or single-layer conductor components, are coated with outer insulating materials outside the conductor to ensure mutual insulation between conductors in the same slot, and also serve as parasitic capacitance medium between metal conductors, forming parasitic capacitance between upper and lower conductors. In this way, the area between the upper conductor and the lower conductor generates a large electric field energy and capacitance, and the corresponding capacitance can compensate for the inductance of the winding conductor and improve the power factor of the generator. In addition, when the motor has low-frequency magnetic field excitation and high-frequency component magnetic field excitation, the electric field participates in energy conversion, which is conducive to the utilization of harmonic electromagnetic energy and has great significance for further improving the power generation of the generator.

[0080] Those skilled in the art will appreciate that the shapes of the elements can be adapted to different groove shapes. Figure 7 a- Figure 7 d, the slot body is an open slot, and the slot shape can be a straight slot with the slot center line passing through the center point of the motor (the cross section is rectangular, see Figure 7 a and Figure 7 c), or a non-straight slot with the center line of the slot deviating from the center point of the motor (the cross section is a parallelogram, see Figure 7 b and Figure 7 d). The cross-sectional shape of the component conductor can be square or circular (typical applications).

[0081] It can be seen that the above-mentioned motor stator winding, the winding (coil) of the present invention can be conveniently matched with a multi-pole motor, and is particularly suitable for use as a stator component of a multi-pole multi-phase motor. The winding (coil) of the present invention has a small end size, saves materials, reduces copper loss, and reduces motor leakage reactance; one side or both sides of the winding conductor are directly in contact with the stator slot, with a large heat dissipation area and a good heat dissipation effect; the coil has a large capacitance effect, which is beneficial to compensate for the motor winding inductance and improve the motor power factor. It can also make full use of the coil harmonic electric field energy, and has great potential for further improving the motor energy conversion rate. Therefore, the winding (coil) of the present invention has the advantages of small leakage reactance, small conductive loss, and high power factor, which is of great significance to improving the power (torque) density and efficiency of the motor.

[0082] It can be seen that the purpose of the present invention has been completely and effectively achieved. The functional and structural principles of the present invention have been demonstrated and explained in the embodiments. Without departing from the principles, the implementation methods can be modified arbitrarily. The present invention includes all modified implementation methods based on the spirit and scope of the claims.

Claims

1. A multi-phase stator winding of a permanent magnet motor, characterized in that: Each phase is formed by connecting one coil or multiple coils, each of which includes a head end element and a terminal element, the head end element is a double-layer conductor element, the terminal element is a single-layer conductor element, and a plurality of double-layer conductor elements are connected between the head end element and the terminal element; the double-layer conductor element includes two layers of conductors, each of which is wrapped with an insulating medium, and an interlayer insulating medium is arranged between the two layers of conductors, and the single-layer conductor element is composed of a single-layer conductor and an outer insulating medium material covering the single-layer conductor; Starting from the head end element, the upper conductors of all double-layer conductor elements are connected in sequence and connected to one end of the terminal element, the incoming line; the other end of the terminal element, the outgoing line, is connected to the lower conductor of the double-layer conductor element; the lower conductors of all double-layer conductor elements are connected in sequence until the head end element ends, so that the upper and lower conductors of the head end element correspond to the input and output ends of the coil respectively; or, starting from the head end element, the lower conductors of all double-layer conductor elements are connected in sequence and connected to the incoming line end of the terminal element, the outgoing line of the other end of the terminal element is connected to the upper conductor of the double-layer conductor element, and the upper conductors of all double-layer conductor elements are connected in sequence until the head end element ends, so that the lower and upper conductors of the head end element correspond to the input and output ends of the coil respectively; Each element constituting one coil corresponds to a stator slot, the number of stator slots spanned by each pair of adjacent elements is the same, and each adjacent element corresponds to a different magnetic pole of the permanent magnet motor rotor; In the double-layer conductor element, each layer of conductor, i.e., the upper layer conductor or the lower layer conductor, is composed of a single conductor or two parallel conductors wrapped with insulating materials; In the single-layer conductor element terminal element, the single-layer conductor is composed of a single conductor wrapped with an insulating material.

2. The multi-phase stator winding of a permanent magnet motor according to claim 1, characterized in that: The multi-phase is greater than or equal to 3 phases.

3. The multi-phase stator winding of a permanent magnet motor according to claim 1, characterized in that: Each phase is composed of multiple coils connected in series or in parallel.

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