Hall sensor system for electric machine

Abstract

Described is a Hall sensor system (120) for an electric machine (100), in particular a wind turbine (1556), the electric machine (100) having a radially inner stator (102) with a stator winding (111) and a radially outer rotor (103) with permanent magnets (114), the Hall sensor system (120) comprising: a body (121) comprising an insertion portion (122) extending in a longitudinal direction (107) and having an end surface (125) at a longitudinal end (124), wherein the insertion portion (122) is configured to be reversibly mountable within the cooling opening (109a) of the stator (102); and a Hall sensor (123) disposed substantially at a longitudinal end (124) of the insertion portion (122), where the longitudinal direction corresponds to the radial direction (107) when the insertion portion (122) is mounted within the cooling duct (109a).

Description

Technical Field

[0001] The present invention relates to a Hall effect sensor (hereinafter referred to as Hall sensor) system for an electric machine, a stator for an electric machine, an electric machine, and a wind turbine comprising the electric machine. Furthermore, the present invention relates to a method for determining the position of an electric rotor using the Hall effect sensor system. Background Art

[0002] Conventionally, controlling a wind turbine's permanent magnet generator (PMG) requires high-resolution electrical rotor position. The goal is to use a sensorless approach (based on back-EMF) for position estimation in generating mode (medium / high-speed operation). For the low-speed range, an observer based on high-frequency signal injection is used. However, the high-frequency injection concept may not be sufficient for surface-mounted PMs and fractional-slot concentrated winding machines, as these machines may not provide sufficiently clear position-related features, which are crucial for the reliability of sensorless approaches, forcing the use of sensors for position feedback.

[0003] One of the most reliable alternatives to sensorless position observers is the use of Hall-effect sensors. These sensors are relatively inexpensive and reliable compared to alternatives such as encoder-based solutions. This is especially true for large PM machine applications where the larger diameter makes encoder installation more complex, expensive, and / or less accurate.

[0004] The use of Hall effect sensors to control electric motors has been practiced before, particularly in BLDC motors where the size of individual machines is in the kW range. However, the application of Hall effect sensors on large machines is less common due to several challenges. A primary challenge is achieving the required high accuracy in sensor position and vibration tolerance. A key factor here is sensor mounting, which is often challenging due to large machine sizes and manufacturing tolerances leading to large deviations in critical dimensions. In wind turbine applications, particularly offshore turbines, ease of component repair is also an advantage in maintaining power generation, and a simple method for replacing failed components is therefore desirable.

[0005] For small and medium-sized motors, Hall sensors are typically embedded in the stator windings or mounted on a PCB that is then attached to the machine stator. However, these concepts are not suitable for large machines because the distance between sensors is long and the stator windings are inaccessible if replacement is necessary. For example, in large machines (especially those with low speeds and high torques, as in direct-drive devices), the winding fill factor is expected to be as high as possible, leaving little room for Hall sensor installations. Due to the high torque density requirements, there is no excess magnet length left at the axial ends of the machine to characterize the Hall sensor distribution. Due to the high pole count in the machine and the wind turbine environment, if the sensor mounting is less rigid (such as via a PCB), potential vibrations will cause significant angular errors.

[0006] Therefore, existing Hall sensor installation methods cannot meet the requirements in wind turbine applications.

[0007] Therefore, there may be a need for a Hall sensor system for an electric machine, there may be a need for a stator for an electric machine, there may be a need for an electric machine, and there may be a need for a wind turbine in which at least some of the above-mentioned problems or disadvantages are alleviated or reduced. Summary of the Invention

[0008] According to an embodiment of the invention, a Hall sensor system is provided for an electric machine, in particular a wind turbine, the electric machine having a radially inner or outer stator with stator windings and a radially outer or inner rotor with permanent magnets, the Hall sensor system comprising: a body comprising an insert portion, which extends in a longitudinal direction and has end surfaces at longitudinal ends, wherein the insert portion is configured to be reversibly mountable in a cooling opening of the stator; and a Hall sensor, which is arranged approximately at a longitudinal end (or tip) of the insert portion, wherein the longitudinal direction corresponds to the radial direction when the insert portion is mounted in the cooling duct.

[0009] The Hall sensor may be at the end of the portion inserted into the cooling duct.

[0010] The electrical machine may be a synchronous electrical machine, in particular a synchronous generator, in particular of a wind turbine.

[0011] When Hall sensor systems are installed at or in the stator of a motor, one or more of these Hall sensor systems can be used to determine the electrical rotor position. The electrical rotor position can then be used to control the motor, particularly using vector control. Vector control may involve transforming and inversely transforming between a fixed coordinate system fixed to the motor and a dq coordinate system that rotates synchronously with the motor's rotor. The electrical rotor position may be required for the corresponding transforms and inverses.

[0012] The Hall sensor system may be used in an electric machine having a radially inner or outer stator and a radially outer or inner rotor with permanent magnets. However, certain embodiments relate to a Hall sensor system adapted for use with an electric machine having a radially inner stator and a radially outer rotor.

[0013] The insert portion, with respect to its geometry and structure, can be adapted for insertion into a straight cooling opening, for example, having a rectangular cross-sectional shape. The insert portion can be the portion of the main body that is fully inserted into the cooling opening, while other portions of the main body may protrude from the cooling opening, particularly in the longitudinal direction of the main body (which corresponds to the radial direction of the generator when installed). The extent of the main body in the longitudinal direction can, for example, be 5 to 20 times greater than the extent of the main body in any other direction transverse to, and particularly perpendicular to, the longitudinal direction.

[0014] The insert portion can be reversibly installed within the stator's cooling opening, allowing for easy insertion and removal. Specifically, bolts or screws may not be required to secure the Hall sensor system to any component, such as the stator, to install the Hall sensor system. This simplifies maintenance and / or replacement of the Hall sensor system in the event of any failure or malfunction. Furthermore, since cooling openings are commonly present or available in conventional stators of large machines, installing the Hall sensor system in such a cooling opening may be advantageous.

[0015] The stator may include a plurality of further cooling openings (e.g. in the teeth), which may be spaced apart in the axial and circumferential directions and may be formed by recesses between the tooth segments, as will be explained in further detail below. Thus, the insertion of the Hall sensor system may have only minimal impact on the cooling operation.

[0016] The end surface of the insert portion can be close to the air gap between the stator and the rotor of the electric machine so that the Hall sensor (which is arranged approximately at the longitudinal end of the insert portion) can sense the magnetic field generated by any permanent magnets of the rotor. The end surface can be a substantially planar or flat end surface, which can extend, for example, in the axial direction and in the circumferential direction of the electric machine when the Hall sensor system is mounted on the stator. When the Hall sensor system is mounted on the stator, the end surface can in particular be flush with the surface of the radially outer part of the stator including the stator winding, or can be slightly lower than said surface.

[0017] The Hall sensor can be configured to measure a magnetic field or magnetic flux that is parallel and / or perpendicular to the end surface of the insertion portion. The Hall sensor can be a sensor that uses the Hall effect to detect the presence and magnitude of a magnetic field. Thus, the output voltage of the Hall sensor can be proportional to the strength of the magnetic field. An electric current can be applied to a thin metal strip. In the presence of a magnetic field perpendicular to the direction of the current, the charge carriers are deflected by the Lorentz force, thereby generating a potential difference between the two sides of the strip. This voltage difference is proportional to the strength of the magnetic field and can be output by the Hall sensor as an indication of the strength or magnitude of the detected magnetic field. The Hall sensor can be an analog Hall sensor and / or a digital Hall sensor. In addition to including basic equipment for determining or measuring a magnetic field, the Hall sensor can also, for example, optionally process raw measurement data, for example to output a digital signal or a substantially digital signal.

[0018] Hall sensor systems can be used or employed, in particular, in electric machines where access to the machine's stator windings and / or permanent magnets is limited. The insert or the entire Hall sensor system can be installed or inserted, in particular, from the radial inside of the stator into the cooling opening. This simplifies or enables installation even in situations where access to the stator windings or magnets is limited.

[0019] According to an embodiment of the invention, the insert portion comprises a winding contact surface, which extends in particular in a width direction and in a height direction, both being perpendicular to the longitudinal direction, to abut a radial inner surface of the stator winding when the insert portion is mounted in the cooling opening, wherein the winding contact surface and the end surface of the insert portion have a predetermined distance from each other in the longitudinal direction.

[0020] The contact surface may in particular be a substantially planar or flat contact surface. The width direction may correspond to the circumferential direction and the height direction may correspond to the axial direction of the electric machine. The radially inner surface of the stator winding may be at a radial location where the stator lamination material delimits the stator slots.

[0021] When the Hall sensor system is mounted on the stator, the end surface of the insert and the winding contact surface are at a predetermined distance from each other in the radial direction. This allows the end surface of the insert to be brought into a predetermined position by bringing the contact surface into contact with or abutting the radially inner surface of the stator winding. This ensures, for example, that the end surface (where the Hall sensor is generally located) is located in a spatial region that enables magnetic field measurement while also avoiding protrusion into the air gap. This allows for precise positioning of the Hall sensor, which can improve measurement characteristics, particularly measurement sensitivity and specificity.

[0022] According to an embodiment of the invention, the insertion portion comprises a first longitudinal portion (particularly a radially inner portion) and a second longitudinal portion (e.g. a radially outer portion), wherein the first longitudinal portion has a larger extent in the width direction than the second longitudinal portion and comprises the winding contact surface.

[0023] In an assembled stator with the Hall sensor system installed, the first longitudinal section is radially more internally located than the second longitudinal section. The second longitudinal section can, in particular, extend at least along the entire radial extent of the winding and can, in particular, further protrude radially outward beyond the radially outer end of the stator winding. The first longitudinal section has a larger extent in the width direction (corresponding to the circumferential direction) than the second longitudinal section, so that the contact surface or the winding contact surface can touch or abut the radial inner surface of the stator winding. When the Hall sensor system is mounted on the stator, the second longitudinal section can be circumferentially adjacent to the circumferential side of the stator winding. In this way, precise positioning of the Hall sensor can be achieved.

[0024] The winding contact surface of the first longitudinal portion of the insertion portion may be at another circumferential position (position in the width direction) or region than the end surface of the second longitudinal portion of the insertion portion.

[0025] According to an embodiment of the present invention, the second longitudinal portion of the insertion part includes an end surface and includes two or more winding contact protrusions on one width (e.g. circumferential) side to contact the stator winding at the circumferential side, wherein in particular the total contact area of ​​the winding contact protrusions reaches 1% to 5% of the area of ​​the circumferential side of the winding.

[0026] The winding contact protrusions may contact or touch, meaning physically contact, the side surfaces or portions of the circumferential sides of the stator winding. When properly installed, a small amount of free space may exist in the radial area between the winding contact protrusions. Therefore, potential irregularities in the flatness of the circumferential surface of the stator winding may not interfere with installation.

[0027] According to an embodiment of the invention, the second longitudinal portion of the insertion part provides elastic properties in a width direction transverse to, in particular perpendicular to, the longitudinal direction, and the width direction corresponds to the circumferential direction when the Hall sensor system is mounted at the stator; the elastic properties enable the system to be reversibly fixed in the cooling opening by press fit and / or form fit, wherein the elastic properties are in particular achieved by at least one of: one or more wedges and / or protrusions, in particular at the end of the second longitudinal portion; an elastic / reversibly deformable material added to the second longitudinal portion; a spring and / or a protrusion and / or a projection and / or a recess and / or a through-hole arranged at the second longitudinal portion.

[0028] The elastic property may enable clamping the insert portion between the stator winding and a structure belonging to the stator or an adjacent stator winding.The elastic property may be achieved by a number of different structural features in order to provide a large flexibility in the construction of the Hall sensor system.

[0029] According to an embodiment of the present invention, the second longitudinal portion of the insertion part includes at least one elastic member on the other width (e.g. circumferential) side, the elastic member particularly including rubber and / or deformable protrusions to contact the cooling opening limiting wall (or another winding in another slot) and apply force along the width (e.g. circumferential) direction, wherein the second longitudinal portion of the insertion part is particularly configured to be clamped between the stator winding and the cooling opening limiting wall (spacer) (or another winding in another slot) by elastic force.

[0030] The cooling openings between circumferentially adjacent stator windings or wire sections may be separated by a cooling opening limiting wall. The cooling opening limiting wall may extend in both radial and axial directions to separate the free space between the two stator windings into two cooling openings (particularly having the same or substantially the same cross-sectional shape). The cooling opening limiting wall may be provided to prevent collapse or deformation of the intended or desired shape of the cooling opening during manufacturing, which involves lamination of the stator.

[0031] If the cooling opening-limiting wall is absent, the corresponding insertion portion has a wider width, allowing it to contact another winding in another circumferentially adjacent slot at the other width side. This provides greater flexibility. Furthermore, the presence of the elastic member allows the Hall sensor system to be secured to the cooling opening via a press-fit.

[0032] According to an embodiment of the invention, a projection of the second longitudinal portion of the insert portion along the longitudinal direction has a rectangular shape which substantially corresponds to the cross-sectional shape of the cooling opening.

[0033] The conventional cooling opening may also have a rectangular shape, and thus, inserting the insert portion into the cooling opening may be facilitated.

[0034] According to an embodiment of the present invention, the body further includes a protrusion portion extending from the first longitudinal portion of the insertion portion in the longitudinal direction to protrude radially inward from the radial inner surface of the stator when the Hall sensor system is mounted at the cooling duct.

[0035] The projection portion may facilitate the Hall sensor system to be held in the hand by, for example, a technician. The technician may access the radial inside of the stator, thereby enabling the Hall sensor system to be inserted or withdrawn (ie reversibly installed).

[0036] According to an embodiment of the present invention, the system further comprises a cover member and a mounting member (in particular a mounting magnet), wherein the cover member is configured to be placed on or above the protrusion portion, and the mounting member is configured to provide a retaining force between the cover member and a radially inner portion of the stator so as to maintain the Hall sensor system in a radial direction.

[0037] The mounting members may include mechanical mounting items such as bolts, clamps.

[0038] The cover member protects the Hall sensor system from mechanical damage. Furthermore, the mounting member holds or secures the Hall sensor system in the radial direction, preventing it from sliding or falling out of the cooling opening in the radially inner direction. This ensures secure radial fixation even in the presence of severe vibrations.

[0039] The clamping features or contact projections and the elastic material provided in the insert part of the Hall sensor system can ensure fixation in the circumferential direction and also partially in the radial direction by means of a force fit. The contact projections and the elastic material on the circumferential side of the insert part can provide a secure fixation due to a form fit.

[0040] According to an embodiment of the present invention, the insertion part and the protrusion part are molded integrally, and the Hall sensor is particularly embedded / encapsulated in the insertion part; and / or the range of the main body in the longitudinal direction is between 5 times and 20 times the range in at least one direction transverse to, in particular perpendicular to, the longitudinal direction; and / or the main body is formed of a non-magnetic, non-conductive, in particular high-temperature resistant material, in particular a plastic material.

[0041] According to an embodiment of the invention, the projection portion also provides a hand-held portion of the body to facilitate insertion and / or withdrawal of the system into the cooling opening by a person.

[0042] The handheld portion may include a grip and, in certain embodiments, may also include a through-hole, into which, for example, a human finger may be inserted, so as to easily withdraw the Hall sensor system from the cooling opening or insert the Hall sensor system into the cooling opening. This may simplify installation or removal.

[0043] The body may be formed, for example, from any thermosetting or thermoplastic material, such as Techtron, HPV.

[0044] The body or the entire Hall system may, for example, be configured to withstand or operate at temperatures between -20°C and 180°C.

[0045] According to an embodiment of the invention, a stator for an electric motor, in particular a wind turbine, is provided, the electric motor having a radially outer rotor with permanent magnets, the stator comprising: a stator yoke having a plurality of radially outwardly projecting teeth and slots therebetween, the teeth and the slots extending in an axial direction, the teeth being formed by axial tooth segments, the axial tooth segments being spaced apart in the axial direction so as to form cooling openings between adjacent tooth segments; a cooling opening limiting wall or a partition wall between two adjacent tooth segments, in particular, for dividing the space between the two adjacent tooth sections into two parts, each part forming a cooling opening; a stator winding partially arranged in the slots; and at least one Hall sensor system according to any of the preceding claims, which is inserted into one of the cooling openings.

[0046] The stator may in particular comprise at least three Hall sensor systems, which are mounted at different locations (or air ducts) in the circumferential direction such that the Hall sensor systems are spaced apart by a specific electrical angle, such as 60° or 120°. Thus, the Hall sensor systems can be used for electrical rotor position determination.

[0047] According to an embodiment of the present invention, there is provided a motor comprising: the stator according to the aforementioned embodiment; and an outer rotor or an inner rotor rotatably supported relative to the stator.

[0048] The electrical machine can, for example, be configured as a generator, in particular as a synchronous generator.

[0049] According to an embodiment of the present invention, there is provided a wind turbine comprising: the motor according to the aforementioned embodiment; and a hub having a plurality of rotor blades mounted thereon, wherein the hub is coupled to a rotor of the motor.

[0050] It should be understood that features disclosed, described, explained or provided for the Hall sensor system, alone or in any combination, may also be provided, used or applied, alone or in any combination, to the method for installing the Hall sensor system according to an embodiment of the present invention, and vice versa.

[0051] According to an embodiment of the present invention, a method is provided for installing a Hall sensor system for an electric machine, in particular a wind turbine, the electric machine having a radially inner or outer stator with a stator winding and a radially outer or inner rotor with permanent magnets, the Hall sensor system comprising: a body comprising an insert portion, which extends in a longitudinal direction and has end surfaces at longitudinal ends; a Hall sensor, which is arranged approximately at a longitudinal end of the insert portion, the method comprising: inserting the insert portion into a cooling opening of the stator along the longitudinal direction, so that the Hall sensor is positioned to sense the magnetic field generated by the permanent magnets of the rotor, wherein the longitudinal direction corresponds to the radial direction of the electric machine.

[0052] Embodiments of the present invention will now be described with reference to the accompanying drawings. The present invention is not limited to the embodiments shown or described. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 Schematically illustrates a portion of a motor according to an embodiment of the present invention in a cross-sectional view along an axial direction;

[0054] Figure 2 Schematically illustrated in a view from the radial outside in the radial direction Figure 1 The part of the motor stator shown in the figure;

[0055] Figure 3 The stator of the electric machine is shown in a view from the radial inside along the radial direction;

[0056] Figure 4 schematically illustrates a portion of an electric machine according to an embodiment of the present invention;

[0057] Figure 5 and Figure 6 The Hall sensor system according to an embodiment of the present invention is shown, which can be used, for example, in Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 In the stator shown in the figure;

[0058] Figure 7 and Figure 8 FIGURE 1 illustrates a Hall sensor system according to an embodiment of the present invention;

[0059] Figure 9 schematically illustrates a portion of an electric machine according to an embodiment of the present invention before insertion of a Hall sensor system;

[0060] Figure 10 Schematically illustrating a method of inserting a Hall sensor system according to an embodiment of the present invention;

[0061] Figure 11 The diagram shows a portion of a motor into which a Hall sensor system according to an embodiment of the present invention has been inserted;

[0062] Figure 12 schematically illustrates an electric machine according to an embodiment of the invention, into which a Hall sensor system according to an embodiment of the invention has been inserted;

[0063] Figure 13 A schematic diagram illustrating a portion of a stator of a motor according to an embodiment of the present invention is shown from a radially outer side;

[0064] Figure 14 illustrates measurement results obtained by a three-Hall sensor system installed in an electric machine according to an embodiment of the present invention;

[0065] Figure 15 A wind turbine according to an embodiment of the invention is schematically illustrated. DETAILED DESCRIPTION

[0066] It should be understood that features or structures with similar structures and / or functions illustrated in different figures may be marked with reference numerals that differ only in the first digit. The description of a particular feature that is not described in detail with respect to a particular embodiment may be taken from the description of this element in the context of other embodiments or figures.

[0067] Figure 1 A partial view of an electric machine 100 according to an embodiment of the present invention is schematically shown in a cross-sectional view perpendicular to the axial direction 101. Figure 1 , radial direction 107 and circumferential direction 108 are indicated, both of which are perpendicular to axial direction 101. Electric motor 100 includes a stator 102 according to an embodiment of the present invention and an outer rotor 103 rotatably supported relative to stator 102. Rotor 103 includes a rotor housing 112 on which radially inwardly projecting permanent magnets 113 are mounted. Permanent magnets 113 are inserted into retaining rails 114 extending in axial direction 101. An air gap 115 is present between stator 102 and rotor 103, typically ranging from 5 mm to 8 mm.

[0068] The stator 102 of the electric motor 100 includes a stator yoke 104 having a plurality of radially outwardly projecting teeth 105 and slots 106 therebetween.

[0069] like Figure 2 Visible in ( Figure 2 ), the electric machine 100 is shown viewed from the outside along a radial direction 107 , the teeth 105 being formed by axial tooth segments 105 a , 105 b , 105 c , 105 d , . . . , which are spaced apart in the axial direction 101 , thereby forming cooling openings 109 between adjacent tooth segments (e.g. 105 a , 105 b ).

[0070] exist Figure 1 and Figure 2 In the embodiment shown in FIG, the stator further includes a cooling opening limiting wall or a cooling opening partition wall 110 between two adjacent teeth (e.g., 105a, 105b), which is used to divide the space between the two adjacent teeth into two parts, each of which forms a cooling opening, e.g., 109a, 109b. The motor, or more specifically, the stator 102, further includes a stator winding 111 partially arranged within the slots 106.

[0071] Figure 1 and Figure 2The electric machine 100 illustrated in FIG further comprises at least one Hall sensor system 120 according to an embodiment of the invention, in particular three Hall sensor systems 120 , which are inserted into one of the cooling openings, for example the cooling opening 109 a .

[0072] Each Hall sensor system 120 of the electric machine 100 includes a body 121 including an insert portion 122 extending in a longitudinal direction (in line with the radial direction 107), wherein the insert portion 122 is configured to be reversibly mounted within the cooling opening 109a of the stator 102. A Hall sensor 123 is generally disposed at a longitudinal end 124 of the insert portion. The insert portion 122 has an end surface 125 at the longitudinal end 124.

[0073] When the insert portion 122 is installed in the cooling duct 109 a , the longitudinal direction of the insert portion 122 or the body 121 corresponds to the radial direction 107 .

[0074] Figure 3 The figure shows a partial perspective view of the electric machine 100 as seen in a radial direction 107 from the radial inside.

[0075] Figure 4 A cross-sectional view taken perpendicular to the axial direction 101 shows in more detail Figure 1 、 Figure 2 and Figure 3 . The insert portion 122 includes a winding contact surface 126 extending in a width direction (collinear with the circumferential direction 108) and in a height direction (collinear with the axial direction 101), both of which are perpendicular to the longitudinal direction and collinear with the radial direction 107, so as to abut (or contact) a radial inner surface 127 of the stator winding 111 when the insert portion 122 is installed in the cooling opening 109a.

[0076] The winding contact surface 126 and the end surface 125 of the insert portion 122 have a predetermined distance d from each other in the longitudinal direction (collinear with the radial direction 107 ).

[0077] The insert portion 122 comprises a first longitudinal portion 128 (particularly a radially inner portion) and a second longitudinal portion 129, wherein the first longitudinal portion 128 has a larger extent in the width direction (collinear with the circumferential direction 108) than the second longitudinal portion 129, and the first longitudinal portion 128 comprises the contact surface 126. The second longitudinal portion 129 of the insert portion 122 comprises an end surface 125 and is formed on one width (circumferential) side (in the circumferential direction). Figure 4 The winding contact projections (or wedges) 130 are included on the circumferential side (in the upper side) to Figure 4The stator winding 111 is contacted at the lower side.

[0078] The second longitudinal portion 129 of the insert portion 122 also provides elastic properties in a width direction transverse to, in particular perpendicular to, the longitudinal direction, which corresponds to the circumferential direction when the Hall sensor system 120 is mounted at the stator, as shown in FIG. Figure 4 The elastic properties are provided by the wedges and / or projections 130 and / or elastic / reversibly deformable material or springs or projections or protrusions.

[0079] The second longitudinal portion 129 of the insertion portion 122 is on the other width (circumferential) side (at Figure 4 The winding 110 includes at least one elastic member 131 on the lower side (in the middle), and the elastic member 131 includes, for example, rubber and / or deformable protrusions to contact the cooling opening limiting wall 110 (or another winding 111 in another slot) and apply force along the width (circumferential) direction 108.

[0080] For example Figure 4 As can be seen in the figure, the second longitudinal portion 129 of the insert portion 122 is clamped between the stator winding 111 and the cooling opening limiting wall 110 (also called "spacer element") by elastic force so as to provide a press fit in the radial direction and a form fit in the circumferential direction 108.

[0081] For example, in Figure 2 As can be seen from the figure, the cross-sectional shape of the cooling opening 109a is trapezoidal, almost rectangular. When a projection is taken along the longitudinal direction (collinear with the radial direction 107), the projection of the second longitudinal portion 129 has the same or similar shape, ie, a rectangular shape.

[0082] The body 121 of the Hall sensor system 120 further includes a protrusion portion 132 extending from the first longitudinal portion 128 of the insert portion 122 in the longitudinal direction to protrude from a radial inner surface 133 of the stator 102 when the Hall sensor system 120 is mounted at the cooling duct 109a.

[0083] The Hall sensor system 120 further includes a cover member 134 and a mounting member 135 (particularly mounted to each other), and the cover member 134 is configured to be placed on or above the projection portion 132, and the mounting member 135 (particularly a magnet) is configured to provide a retaining force 136 between the cover member 134 and the radially inner portion of the stator 102 to retain the Hall sensor system 120 in the radial direction 107. The projection portion 132 can be configured as a handheld portion to facilitate installation of the system into the cooling opening and / or withdrawal of the system from the cooling opening 109a by a person.

[0084] Embodiments of the present invention enable the mounting of Hall-effect sensors inside the cooling ducts of large permanent magnet electric machines, particularly where access to the machine's stator windings and / or magnets is limited or impossible. The Hall-effect sensor 123 is mounted on a body 121 (also referred to as a "bracket," particularly a "non-magnetic bracket") that can be (partially) inserted into the inside of the stator, facing outward (air gap). This allows the sensor to be installed or replaced without requiring direct access to the machine's windings or magnets.

[0085] The body (also called "carriage") can be equipped with a single or multiple springs that push the sensor against the side of the stator winding. Such a fixation can allow the sensor to be kept attached to a more accurate reference point and thus provide the highest possible position accuracy in the circumferential direction. The spring effect can be achieved by making the carrier (or body 121) of a special shape or by adding elastic material to the edge of the sensor or body, and those methods are illustrated in Figure 5 and Figure 6 middle.

[0086] thus, Figure 5 and Figure 6 The schematic diagram shows a Hall sensor system 520, 620 according to an embodiment of the present invention viewed along a height direction 501, 601, which corresponds to the axial direction when the Hall sensor system 520, 620 is mounted on a stator. The width direction is indicated by reference numerals 508, 608, respectively, and the longitudinal direction is indicated by reference numerals 507, 607, respectively.

[0087] Figure 5 The second longitudinal portion 529 of the insertion portion 522 of the Hall sensor system 520 shown in FIG. 5 includes an end surface 525 and a second longitudinal portion 529 of the insertion portion 522 of the Hall sensor system 520 shown in FIG. 5 . Figure 5 The stator winding includes a winding contact projection (or wedge) 530 on the upper side (in the middle) which contacts the stator winding at the circumferential side. Similar winding contact projections or wedges 630 are provided on the stator winding. Figure 6 At the Hall sensor system 620 shown in FIG.

[0088] The second longitudinal portion 529 of the insertion portion 522 of the Hall sensor system 520 is on the other width side (at Figure 5 and Figure 6 The lower side of the cooling opening includes at least one elastic member 536, 636 to contact the cooling opening limiting wall (e.g. Figure 4 10 ) or another winding in another slot and applies forces 537 , 637 in width directions 508 , 608 , respectively.

[0089] exist Figure 5In the embodiment 520 shown in FIG, the elastic member 536 is configured as a rubber protrusion 538. Figure 6 In the embodiment 620 illustrated in FIG, the resilient member 536 is configured as a deformable protrusion 639 that is flexible due to a recess or through-hole 640 within the body 621 .

[0090] If there are impurities or unevenness inside the cooling opening after the manufacturing process (e.g. painting), the bracket (or body) can be designed with wedges. The wedges can limit the contact surface between the sensor and the side surface of the winding, so as to reduce the possibility that any impurities will cause additional position errors between the winding and the sensor in the circumferential direction. Figure 5 、 Figure 6 as well as Figure 4 The wedge and spring are presented and their functions are shown in FIG.

[0091] The distance pins (including the winding contact surfaces 526, 626) prevent the sensor from being pushed too far into the air gap, which could cause damage to the sensor by being struck by magnets passing on the rotor.

[0092] Figure 7 and Figure 8 The Hall sensor system 720 according to an embodiment of the present invention is shown, which includes a main body 721 and a cover member 734 and a mounting member (particularly a magnet) 735. The cover member 734 including the magnet 735 can be placed over the protruding portion 732 of the main body 721, as shown in FIG. Figure 8 As shown in Figure 1 , the body or bracket can be equipped with a magnetic cap that prevents the sensor from sliding out and protects the bracket from external mechanical damage, such as from maintenance personnel stepping on the sensor. This design also helps ensure the sensor's radial position, thereby sensing the magnet's electromagnetic field. If the sensor fails or needs to be positioned in a different location, the magnetic cap can be removed and the bracket can be removed, allowing the sensor or the entire bracket to be replaced.

[0093] Figure 9 、 Figure 10 and Figure 11 The figure shows the installation process of the sensor system at the stator according to an embodiment of the present invention. Figure 9 The radially inner stator surface 933 of the stator is shown as seen along the radial direction 907, along with the stator windings 911 and the cooling opening limiting wall 910. Selected cooling openings 909a are marked with paint 940, indicating the desired location of the Hall sensor system.

[0094] Figure 10 The step of inserting the Hall sensor system 920 into the selected cooling opening 909a of the stator 902 is shown.

[0095] Figure 11 The Hall sensor system 920 is shown fully inserted into the cooling opening. A sensor signal cable 941 is provided to transmit the measurement signal to any processing or control equipment. The Hall sensor system is installed or inserted from the inside of the stator. Paint or varnish 940 is used to identify and mark the air duct where the sensor is to be inserted.

[0096] As a final installation step, the cover 934 and mounting magnets are placed over the inserted body to create a Figure 12 The situation shown in the figure.

[0097] Figure 13 is a schematic illustration of the radially outer side of the stator 902 after the Hall sensor system 920 is installed in the cooling duct 909a. The end surface 925 is ideally flush with the radially outer surface 942 of the stator 902. In the assembled motor, the rotor will be positioned at Figure 13 Above the drawing plane shown in .

[0098] Figure 14 Graphs 1450, 1451, and 1452 illustrate three Hall sensor systems installed in a motor and used to measure magnetic fields or flux to determine rotor position. The abscissa represents time, and the ordinate represents the strength of the detected signal. Curves 1453, 1454, and 1455 illustrate the detected magnetic field strengths of the three Hall sensor systems spaced apart by electrical degrees (e.g., 120° or 60°). Each sensor has a duty cycle (i.e., 50%).

[0099] Figure 15 A wind turbine 1556 according to an embodiment of the present invention is schematically illustrated and includes a wind turbine tower 1557 and a nacelle 1558 mounted on top of the tower. The nacelle 1558 houses a generator 1500 according to an embodiment of the present invention, which is mechanically connected to a hub 1559 where a plurality of rotor blades 1560 are mounted.

[0100] In a typical generator design with distributed windings, the angular displacement between the stator teeth and, therefore, the air ducts, is 60 electrical degrees. Three Hall sensors are typically angularly offset by 120 degrees, so the sensors may have to be installed in three alternating air ducts. This may be physically limited by the specific stator segment assembly. Combinations with 60 degrees between the Hall sensors are also acceptable, with the only change being in the software configuration. This allows for flexible air duct selection for sensor installation, making it easy to select a new air duct if replacing a sensor in the same air duct presents difficulties.

[0101] Embodiments of the present invention may provide the following advantages:

[0102] A simple and robust solution for precisely mounting sensors inside large permanent magnet motors;

[0103] A mechanism that allows for easy replacement of faulty sensors;

[0104] High vibration resistance solutions in large permanent magnet motors;

[0105] Installation methods that are less intrusive to machine components and have little impact on machine performance;

[0106] The ability to flexibly install and reconfigure sensors.

[0107] It should be noted that the term "comprising" does not exclude other elements or steps, and "a" or "an" does not exclude a plurality. Moreover, elements described in connection with different embodiments may be combined. It should also be noted that reference signs in the claims should not be construed as limiting the scope of the claims.

Claims

1. A Hall sensor system (120) for an electric machine (100), in particular a wind turbine (1556), the electric machine (100) having a radially inner or outer stator (102) with a stator winding (111) and a radially outer or inner rotor (103) with permanent magnets (114), the Hall sensor system (120) comprising: a body (121), the body (121) comprising an insert portion (122), the insert portion (122) extending in a longitudinal direction (107) and having an end surface (125) at a longitudinal end (124), wherein the insert portion (122) is configured to be reversibly mountable within a cooling opening (109a) of the stator (102); a Hall sensor (123) disposed substantially at a longitudinal end (124) of the insertion portion (122), Wherein, when the insert portion (122) is installed in the cooling pipe (109a), the longitudinal direction corresponds to the radial direction (107).

2. System according to the preceding claim, wherein The insert portion (122) comprises a winding contact surface (126) extending in particular in a width direction and a height direction both perpendicular to the longitudinal direction to abut a radial inner surface (127) of the stator winding (111) when the insert portion is mounted in the cooling opening, The winding contact surface (126) and the end surface (125) of the insert portion (122) are at a predetermined distance (d) from each other along the longitudinal direction (107).

3. A system according to any one of the preceding claims, wherein The insertion portion (122) includes a first longitudinal portion (128) and a second longitudinal portion (129), The first longitudinal portion (128) has a larger extent in the width direction (108) than the second longitudinal portion (129) and includes the winding contact surface (126).

4. A system according to any one of the preceding claims, wherein The second longitudinal portion (129) of the insert portion (122) comprises the end surface (125) and comprises two or more winding contact projections (130) on one width side, in particular the circumferential side, for contacting the stator winding (111) at the circumferential side, In particular, the total contact area of ​​the winding contact projections is limited to 1% to 5% of the area of ​​the circumferential side of the winding.

5. The system according to any one of the preceding claims, in, a second longitudinal portion (129) of the insert portion (122) providing elastic properties in a width direction transverse to, in particular perpendicular to, the longitudinal direction, the width direction corresponding to a circumferential direction when the Hall sensor system is mounted on the stator; The elastic properties enable the system to be reversibly fixed within the cooling opening by force-fit and / or form-fit, The elastic property is achieved in particular by at least one of the following: one or more wedges (130) and / or projections, in particular at the ends of said second longitudinal portion; an elastic / reversibly deformable material (131) added to the second longitudinal portion (129); A spring and / or a projection and / or a protrusion and / or a recess and / or a through hole are provided at the second longitudinal portion (129).

6. A system according to any one of the preceding claims, wherein The second longitudinal portion (129) of the insert portion (122) comprises at least one elastic member (131) on the other width side, the elastic member (131) particularly comprising rubber and / or a deformable protrusion to contact the cooling opening limiting wall (110) or another winding (111) in another slot and to apply a force in the width direction (108), The second longitudinal portion (129) of the insert portion (122) is particularly configured to be clamped between the stator winding and the cooling opening limiting wall (110) or another winding (111) in another slot by elastic force.

7. A system according to any one of the preceding claims, wherein A projection of the second longitudinal portion (129) of the insert portion (122) along the longitudinal direction (107) has a rectangular shape that substantially corresponds to a cross-sectional shape of the cooling opening (109a).

8. The system according to any one of the preceding claims, wherein the body further comprises: A protrusion portion (132) extends from a first longitudinal portion (128) of the insert portion (122) in the longitudinal direction (107) to protrude radially inward from a radial inner surface (133) of the stator (102) when the Hall sensor system (120) is mounted at the cooling duct (109a).

9. System according to the preceding claim, further comprising: a cover member (134) and a mounting member (135), wherein the cover member (134) is configured to rest on or above the projection portion (132), and the mounting member (135) is configured to provide a retaining force between the cover member and a radially inner portion of the stator (102) to retain the Hall sensor system in the radial direction, The mounting member particularly comprises a mounting magnet (135).

10. The system according to any one of the preceding claims, in, The inserting portion (122) and the protruding portion (132) are integrally formed, and the Hall sensor is particularly embedded / encapsulated in the inserting portion; and / or The extent of the body in the longitudinal direction is between 5 and 20 times the extent in at least one direction perpendicular to the longitudinal direction; and / or The main body (121) is formed of a non-magnetic, non-conductive, especially high-temperature resistant material, especially a plastic material.

11. The system of any preceding claim, the projection portion (132) further providing a hand-held portion of the body to facilitate insertion and / or withdrawal of the system into and / or from the cooling opening by a person.

12. A stator (102) for an electric machine (100), in particular a wind turbine, the electric machine (100) having a radially outer rotor with permanent magnets, the stator (102) comprising: A stator yoke having a plurality of radially outwardly projecting teeth (105) and slots (106) therebetween, the teeth and slots extending in an axial direction (101), the teeth being formed by axial tooth segments (105a, 105b, 105c, 105d), the axial tooth segments (105a, 105b, 105c, 105d) being spaced apart in the axial direction (101) so as to form cooling openings (109) between adjacent tooth segments; In particular, a cooling opening limiting wall (110) or a partition wall between two adjacent tooth portions, which is used to divide the space between the two adjacent tooth portions into two parts (109a, 109b), each part forming a cooling opening; a stator winding (111) partially arranged in the slot (106); At least one Hall sensor system (120) according to any one of the preceding claims, which is inserted into one of the cooling openings (109a).

13. An electric motor (100), comprising: A stator (102) according to the preceding claim; An outer rotor (103) is rotatably supported relative to the stator.

14. A wind turbine (1556), comprising: An electric machine (1500) according to the preceding claim; A hub (1559) is mounted with a plurality of rotor blades (1560), wherein the hub (1559) is coupled to the rotor (103) of the motor (1500).

15. A method for installing a Hall sensor system (120) for an electric machine (100), in particular a wind turbine, the electric machine (100) having a radially inner stator (102) with a stator winding (111) and a radially outer rotor (103) with permanent magnets (113), The Hall sensor system comprises: a main body (121) comprising an insert portion (122) extending in a longitudinal direction (107) and having an end surface (125) at a longitudinal end (124); a Hall sensor (123) disposed substantially at a longitudinal end (124) of the insertion portion (122), The method comprises: inserting the insert portion (122) into the cooling opening (109a) of the stator (102) along the longitudinal direction so that the Hall sensor (123) is positioned to sense the magnetic field generated by the permanent magnet (113) of the rotor, Wherein, the longitudinal direction corresponds to the radial direction (107) of the motor.

16. A method of mounting at least three Hall sensor systems to an electric motor, the method comprising: Selecting at least three cooling openings (109a) of the stator (102) that are mutually displaced by 120° or 60° in electrical angle; The method according to the preceding claim 15 is carried out for each of the selected cooling openings.

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