Synchronous reluctance motor and design method thereof

Abstract

The invention provides a synchronous reluctance motor and a design method thereof, the synchronous reluctance motor comprises a rotor and a stator which are coaxially arranged with a rotating shaft of the synchronous reluctance motor, the rotor comprises a rotor iron core, a plurality of magnetic isolation grooves are formed in the rotor iron core, the magnetic isolation grooves penetrate through the rotor iron core in the axial direction and extend on a plane perpendicular to the axial direction, each of the plurality of magnetic isolation grooves comprises a central part which extends along the tangential direction on the plane and extension parts which are positioned on the two sides of the central part and extend to the outer edge close to the rotor core, and the central part and the extension parts are filled with conductive materials; the stator comprises a stator iron core and a stator winding arranged in a stator groove of the stator iron core, the stator winding is an aluminum wire winding, the power supply frequency of the stator winding is twice of the power frequency, and the electromotive force effective value of the stator winding is the same as that of a power frequency power supply.

Description

Technical Field

[0001] The present invention relates to the field of motors, and specifically, to an asynchronous starting synchronous reluctance motor and its design method. Background Art

[0002] Permanent magnet motors have good low-speed performance and large torque, but the cost of rare earth permanent magnets is high. Synchronous reluctance motors have the advantages of balanced full-speed performance, controllable cost, and high reliability, and are suitable for most working conditions.

[0003] An asynchronous starting synchronous reluctance motor is a high-efficiency synchronous reluctance motor with little or no permanent magnet, and has been widely regarded in the fields of home appliances, automobiles, aerospace, etc. Moreover, after adding permanent magnet assistance, the synchronous reluctance motor has a simple structure, optimized cost, good flux-weakening effect, significant energy-saving effect, and is suitable for speed regulation in the full-speed range of high, medium, and low speeds. Since the asynchronous starting synchronous reluctance motor has a wide range of applications, there is a need for an asynchronous starting synchronous reluctance motor with little or no permanent magnet, which is structurally compact, reliable, and has a high power density.

[0004] Motor windings are generally made of copper wire. Compared with copper wire, the advantages of aluminum wire are light weight, low cost, and sufficient resources. On the other hand, it can also improve the weight reduction of traditional motors. However, due to the restriction of conductivity parameters, it is difficult to improve the motor efficiency, and the heat generation problem of the aluminum wire winding cannot be well solved. Summary of the Invention

[0005] To meet the continuously improving technical requirements, an embodiment of the present disclosure provides a synchronous reluctance motor, including a rotor and a stator coaxially arranged with the rotating shaft of the synchronous reluctance motor. The rotor includes a rotor core, and a plurality of magnetic isolation slots are formed in the rotor core, axially penetrating the rotor core and extending in a plane perpendicular to the axial direction. Each of the plurality of magnetic isolation slots includes a central portion extending tangentially in the plane and extending portions located on both sides of the central portion and extending to near the outer edge of the rotor core. The central portion and the extending portions are filled with a conductive material. The stator includes a stator core and a stator winding disposed in the stator slots of the stator core. The stator winding is an aluminum wire winding, the supply frequency of the stator winding is twice the power frequency, and the effective value of the stator winding electromotive force is the same as that of the power frequency power supply.

[0006] According to the embodiment, the number of pole pairs of the synchronous reluctance motor is two or more pairs.

[0007] According to the embodiment, compared with the standard size, the number of turns of the stator winding is halved and the cross-sectional area of each turn is increased to twice.

[0008] According to the embodiment, compared with the standard size, the sizes of the stator teeth and / or the stator yoke of the stator are increased and the cross-sectional area of the stator slot is reduced to reduce the iron loss.

[0009] According to an embodiment, compared with the standard size, the cross-sectional area of the stator slots and the number of turns of the winding remain unchanged, and the length of the motor iron core is reduced.

[0010] According to an embodiment, the central portion of each of the plurality of magnetic isolation slots communicates with the extension portion, and at least one of an insulating separation material, a permanent magnet, and a magnetic bridge is disposed at the rotor q-axis in the central portion.

[0011] According to an embodiment, the central portion of each of the plurality of magnetic isolation slots communicates with the extension portion, and an insulating separation material or a magnetic bridge is disposed between the conductive material filled in the central portion and the conductive material filled in the extension portion.

[0012] An embodiment of the present disclosure provides a design method for a synchronous reluctance motor. The synchronous reluctance motor includes a rotor and a stator coaxially arranged with the rotating shaft of the synchronous reluctance motor. The rotor includes a rotor iron core, and a plurality of magnetic isolation slots are formed in the rotor iron core and penetrate the rotor iron core axially and extend in a plane perpendicular to the axial direction. Each of the plurality of magnetic isolation slots includes a central portion extending tangentially in the plane and extension portions located on both sides of the central portion and extending to near the outer edge of the rotor iron core. The central portion and the extension portions are filled with a conductive material. The stator includes a stator iron core and a stator winding disposed in the stator slots of the stator iron core. The stator winding is an aluminum wire winding. The design method includes: calculating the number of series turns N per phase of the stator winding according to the equation E = 4.44fN k Φ, where E is the induced electromotive force of the stator winding, f is the supply frequency of the stator winding, and Φ is the magnetic flux of the stator winding. k is the winding coefficient, the supply frequency f is twice the power frequency, and the induced electromotive force of the stator winding E is the same as that of the power frequency power supply.

[0013] According to an embodiment, the number of pole pairs of the synchronous reluctance motor is two or more pairs, and compared with the standard size, the number of turns of the stator winding is halved and the cross-sectional area per turn is increased to twice.

[0014] According to an embodiment, the number of pole pairs of the synchronous reluctance motor is two or more pairs, and compared with the standard size, the sizes of the stator teeth and / or the stator yoke of the stator are increased and the cross-sectional area of the stator slots is reduced to reduce iron loss.

[0015] The synchronous reluctance motor according to the embodiment can be started by adopting an asynchronous motor control strategy, so that it can equivalently replace the application scenarios of asynchronous motors, and has significant advantages of being lightweight and highly efficient compared with traditional asynchronous motors. In addition, when the power supply frequency of the synchronous reluctance motor is increased to twice the power frequency, the performance degradation of the motor caused by using aluminum wire instead of copper wire is improved, and the energy efficiency level of the motor is significantly increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Through the following specific embodiments in conjunction with the drawings, the above and other aspects, features and advantages of the present disclosure will be more clearly understood. In the drawings: Figure 1 is a schematic cross-sectional view of a synchronous reluctance motor according to an embodiment of the present invention; Figure 2 is a schematic cross-sectional view of a rotor of a synchronous reluctance motor according to an embodiment of the present invention; Figure 3 is a schematic cross-sectional view of a rotor of a synchronous reluctance motor according to an embodiment of the present invention; Figure 4 is a schematic cross-sectional view of a rotor of a synchronous reluctance motor according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] The following specific embodiments are provided to help the reader obtain a comprehensive understanding of the methods, devices, and / or systems described herein. However, after understanding the disclosure of the present application, various variations, modifications, and equivalents of the methods, devices, and / or systems described herein will be apparent. For example, the order of operations described herein is merely an example and is not limited to the order set forth herein. Rather, changes that will be apparent after understanding the disclosure of the present application may be made, except for operations that must occur in a specific order. In addition, descriptions of features known in the art may be omitted for the sake of clarity and conciseness. In order to enable those skilled in the art to better understand the present invention, the specific embodiments of the present invention will be described in detail below with reference to the drawings.

[0018] The Y series asynchronous motors specified by the national standard (GB) and their subsequent modified models (Y2, Y3, YE3, and YX3) are dedicated to improving the energy consumption level of the motors. The synchronous reluctance motor has low energy consumption and high cost performance. The present disclosure proposes to improve the structural parameters and power supply frequency of the synchronous reluctance motor so that it can be equivalently replaced with the national standard asynchronous motor and has a significant comparative advantage in terms of efficiency compared with traditional asynchronous motors.

[0019] Synchronous reluctance motors have low energy consumption and high cost performance. However, the drive of synchronous reluctance motors requires a V / F controller or a vector controller capable of judging the rotor position to start according to the synchronous motor control strategy. To avoid the high cost of the controller, a squirrel-cage coil (starting cage) can be set in the structure of the rotor of the synchronous reluctance motor to achieve asynchronous starting, so that the synchronous reluctance motor can adopt the asynchronous motor control strategy to start, and thus can equivalently replace the application scenarios of asynchronous motors.

[0020] In addition, technicians in the motor field have tried many times to replace copper wire with aluminum wire to achieve lightweight. However, the conductivity / resistivity parameters of aluminum wire restrict the current density of the winding, resulting in parameters such as power and efficiency not meeting the requirements. The resistivity of aluminum wire is generally more than 1.6 times that of copper wire. In a conventional motor structure, when the current density of the motor winding of copper wire can be selected as 4 - 6 A / mm 2 , the current density of the motor winding of aluminum wire can only reach 2.4 - 3.6 A / mm 2 . In other words, in the case of the same current density, the ratio of the conductor cross-sectional area of aluminum wire to that of copper wire needs to reach more than 1.6 times, but it is impossible to meet enough space to install a larger volume of aluminum wire under the premise of the same slot type and stator slot cross-sectional area.

[0021] To address the above problems, considering that the inductance of the same electrical appliance changes with frequency in different frequency power supply systems, the power and efficiency of an inductive electrical appliance for a 50 Hz frequency change based on the change of inductance in a 60 Hz frequency power supply system. Thus, the present disclosure proposes to increase the power supply frequency to twice the power frequency (100 Hz), so that the inductance value of each turn of the motor winding increases proportionally based on the multiple of the frequency. That is to say, the synchronous reluctance motor with an increased power supply frequency attempts to obtain the same or higher magnetic flux under the condition of reducing the number of winding turns and / or the stator slot cross-sectional area, so that the stator slot cross-sectional area for setting aluminum wire can be adjusted more flexibly. When combined with the above improvements and the power supply frequency is increased to twice the power frequency (100 Hz), the properties of the conductor material can be appropriately reduced, thereby improving the performance degradation caused by replacing copper wire with aluminum wire.

[0022] Moreover, since the synchronous reluctance motor can start by adopting the asynchronous motor control strategy, the motor control system of the present disclosure can be an open-loop system. The open-loop system can include a frequency doubling device. The frequency doubling device can be a simplified structure of an existing frequency conversion device, which can simply increase the motor operating frequency from the power frequency to the set frequency, and its output voltage value remains unchanged, so that the motor speed is increased to 2 times the speed based on the conventional speed of a motor with a specific number of pole pairs, and the equivalent number of pole pairs is halved. For example, when the power frequency is 50 Hz, the power supply frequency is doubled to 100 Hz, so that the conventional speed of a four-pole motor of 1500 rpm is increased to 3000 rpm, thus being equivalent to a two-pole motor.

[0023] According to an embodiment of the present disclosure, an asynchronous-start synchronous reluctance motor is provided, which includes a rotor and a stator coaxially arranged with the rotating shaft of the synchronous reluctance motor. The rotor includes a rotor core, and a plurality of magnetic isolation slots are formed in the rotor core, axially penetrating the rotor core and extending in a plane perpendicular to the axial direction. Each of the plurality of magnetic isolation slots includes a central portion extending tangentially in the plane and extending portions located on both sides of the central portion and extending to near the outer edge of the rotor core. The central portion and the extending portions are filled with a conductive material. The stator includes a stator core and a stator winding disposed in the stator slots of the stator core. The stator winding is an aluminum wire winding, and the supply frequency is twice the power frequency, and the effective value of the winding electromotive force is the same as that of the power frequency power supply. The asynchronous-start synchronous reluctance motor according to the embodiment has significant advantages of being lightweight and having high efficiency compared with a traditional asynchronous motor.

[0024] Figure 1 It is a schematic cross-sectional view of a synchronous reluctance motor according to an embodiment of the present invention.

[0025] Referring to Figure 1 , the synchronous reluctance motor according to the embodiment includes a rotor 20 and a stator 10 coaxially arranged with the rotating shaft of the synchronous reluctance motor. The stator 10 of the synchronous reluctance motor includes a stator core and a stator winding 12 disposed in the stator slots of the stator core. The stator winding 12 is an aluminum wire winding, and the supply frequency of the stator winding is twice the power frequency, and the effective value of the stator winding electromotive force is the same as that of the power frequency power supply. The rotor 20 of the synchronous reluctance motor is in the structural form of a synchronous reluctance motor without a separately provided squirrel-cage coil. Magnetic isolation slots 22 are provided in the rotor core, and aluminum is cast in the magnetic isolation slots 22 after stacking rotor punching sheets to form a squirrel-cage coil 21. Specifically, a plurality of magnetic isolation slots 22 are formed in the rotor core, axially penetrating the rotor core and extending in a plane perpendicular to the axial direction. For example, the number of layers of the magnetic isolation slots can be 3 layers, and can also be 4 layers. Each of the plurality of magnetic isolation slots 22 includes a central portion 221 extending tangentially in the plane and extending portions 222 located on both sides of the central portion 221 and extending to near the outer edge of the rotor core. The central portion 221 and the extending portions 222 are filled with a conductive material. The central portion 221 extending tangentially may mean that the central portion 221 has a straight shape in the plane and extends in the tangential direction perpendicular to the rotor radial direction, and may also mean that the central portion 221 has a curved shape and the virtual connection line at both ends is parallel to the tangential direction. That is to say, the rotor 20 of the synchronous reluctance motor according to the embodiment does not separately provide a squirrel-cage structure near the outer edge of the rotor outside the original magnetic isolation slots, but forms a squirrel-cage coil 21 from a conductor material inside the magnetic isolation slots.

[0026] Due to the pole positions of the motor stator windings, the rotation direction of the generated rotating magnetic field is opposite at both ends of each magnetic isolation slot. Therefore, there are differences or even opposites in the phases of the induced currents at both ends of the magnetic isolation slot. To avoid the generation of eddy currents inside the conductor, an insulating region is provided at the middle position of the magnetic isolation slot to divide the entire magnetic isolation slot into two or more segments, separating the conductors in a single magnetic isolation slot. According to one embodiment, referring to Figure 1 , the central portion 221 of each of the plurality of magnetic isolation slots 22 communicates with the extension portion 222, wherein an insulating separation material 223 is provided at the rotor q-axis in the central portion 221. The material for separating the squirrel-cage coils can be a heat-resistant material such as asbestos board, or other non-magnetic, insulating and heat-resistant materials.

[0027] The present disclosure employs a four-pole or more-pole motor. The magnetic circuit lengths of the stator and rotor of a multi-pole pair (e.g., two or more pole pairs) motor are significantly shorter than those of a motor with a small number of pole pairs (e.g., one pole pair), and it has a significant effect in reducing the iron loss caused by high frequencies.

[0028] When the supply frequency of the stator winding is twice the power frequency, since the frequency increases while the voltage remains unchanged, the number of turns of the stator winding can be reduced in a corresponding proportion. The wire diameter of the aluminum wire with high resistivity (or copper-clad aluminum wire) can also be increased to replace the conventional copper wire with aluminum wire to achieve the inductance (magnetic flux) required for motor operation. When the cross-sectional area of the stator slot remains unchanged, for example, compared with the standard size, the number of turns of the stator winding is halved and the cross-sectional area of each turn is increased to twice. The standard size can be the standard stator size list of the national standard Y series motor, but it is not limited thereto. The stator size of a conventional synchronous reluctance motor applicable to copper wire can also be referred to, or the preliminary calculated value of the stator size based on the power value, etc. In addition, the stator slot can be trapezoidal to optimize the cross-sectional area to increase the cross-sectional area of each turn or improve the slot fill factor.

[0029] In the process of electromagnetic calculation of an AC motor, the number of series turns N per phase of the motor winding is calculated according to the following formula (1): E = 4.44fN k Φ (1) where E is the induced electromotive force of the stator winding, f is the supply frequency of the stator winding, Φ is the magnetic flux of the stator winding, k is the winding coefficient.

[0030] The voltage of a conventional V / F controller or vector controller changes proportionally with the change of the supply frequency f, but does not consider the influence of the angular frequency on the number of turns of the winding.

[0031] It is proposed here that when the induced electromotive force E of the stator winding and the magnetic flux Φ of the stator winding remain unchanged, the number of series turns N per phase is inversely proportional to the supply frequency f of the stator winding; when the supply frequency f of the stator winding is increased to twice, the number of series turns N per phase is reduced by half.

[0032] According to Equation 1, the present disclosure proposes that the number of winding turns can be reduced by increasing the power supply frequency. For example, increasing the power supply frequency of the motor from the industrial frequency of 50 Hz to 75 Hz can reduce the number of winding turns by 1 / 3. When the power supply frequency of the motor is increased to 100 Hz, the number of winding turns can be halved. In a motor with a copper wire winding, according to Equation 1, when the material properties remain unchanged, increasing the frequency of power supply can be used to reduce the number of winding turns and the cross-sectional area of the stator slots, thereby increasing the stator tooth width and the stator yoke width; alternatively, increasing the frequency of power supply can shorten the length of the stator and rotor cores.

[0033] According to another embodiment, when using aluminum wire instead, compared with the standard size, the stator teeth and / or the stator yoke size of the stator increase and the cross-sectional area of the stator slots decreases to reduce iron loss. Since the frequency is increased to twice, and the resistivity of the aluminum material only increases to about 1.6 times, the number of turns is halved (50%). The cross-sectional area of each turn of the conductor increases to 1.6 times. The cross-sectional area of the winding in the stator slots is 1.6×50%, so the cross-sectional area of the winding is 80% of the standard size, and the cross-sectional area of the stator slots can be reduced by 20% to increase the stator tooth width. Optionally, the stator yoke width can also be increased. According to Φ = BS, where B is the magnetic induction intensity and S is the cross-sectional area of the stator tooth or yoke, we can get E = 4.44fN k BS. When the induced electromotive force E of the stator winding and the magnetic flux Φ of the stator winding remain unchanged, increasing the stator tooth width and / or the yoke width can reduce the magnetic induction intensity B, thereby significantly reducing the iron loss.

[0034] Since the frequency is increased to twice, and the resistivity of the aluminum material only increases by about 1.6 times, therefore, when using aluminum material and the cross-sectional area of the stator slots remains unchanged, other parameters can be further adjusted. For example, compared with the standard size, the cross-sectional area of the stator slots and the number of winding turns remain unchanged, and the length of the motor core is reduced, thereby reducing the weight of the core and the copper wire by 20% or more; optionally, the outer diameter of the motor core can also be reduced to achieve a lightweight effect, so as to realize the miniaturization and lightweight of the motor.

[0035] An embodiment of the present disclosure provides a design method for a synchronous reluctance motor. The synchronous reluctance motor includes a rotor and a stator coaxially arranged with the rotating shaft of the synchronous reluctance motor. The rotor includes a rotor core, and a plurality of magnetic isolation slots are formed in the rotor core axially penetrating the rotor core and extending in a plane perpendicular to the axial direction. Each of the plurality of magnetic isolation slots includes a central portion extending tangentially in the plane and extending portions located on both sides of the central portion and extending to near the outer edge of the rotor core. The central portion and the extending portions are filled with a conductive material. The stator includes a stator core and a stator winding arranged in the stator slots of the stator core. The stator winding is an aluminum wire winding. The method includes: the equation E = 4.44fN kCalculate the number of turns N in series per phase of the stator winding, where E is the induced electromotive force of the stator winding, f is the supply frequency of the stator winding, and Φ is the magnetic flux of the stator winding. k is the winding coefficient.

[0036] Table 1 below shows an embodiment of a synchronous reluctance motor based on a frame size of 90S-4. The dimensions and performance parameters of the Y2 series 90S-4 prototype asynchronous motor and the dimensions and performance parameters of the improved synchronous reluctance motor are as shown in Table 1 below. Among them, the line voltage is 380V, the output power is 1500W, and the rated speed is 3000rpm.

[0037] Table 1

[0038] Referring to Table 1, the synchronous reluctance motor according to the embodiment uses aluminum wire and increases the supply frequency to twice, which can realize the operation of a four-pole motor as a two-pole motor, and significantly improve in terms of efficiency, cost, and weight reduction.

[0039] In terms of losses, it generally includes resistance loss and iron loss. The resistance loss is the loss caused by the current heating effect of the winding, which is called copper loss in a conventional motor.

[0040] The resistance loss of the synchronous reluctance motor is mainly manifested as DC loss, and the AC loss can be ignored. After the supply frequency is increased to 100Hz and other parameters such as voltage, magnetic induction intensity, and core cross-sectional area remain unchanged, the number of turns of the winding is halved, so the DC resistance loss is halved. Considering factors such as temperature rise, the actual resistance loss is slightly increased compared with the calculated value. For example, the resistance loss of a 1.1kW synchronous reluctance motor drops by about 80W.

[0041] In terms of iron loss, with the same current-carrying capacity, the volume occupied by aluminum wire is about 1.63 times that of copper wire. When the supply frequency is increased to twice, the volume of aluminum wire can be halved. And because aluminum wire is softer than copper wire, the slot fill factor can be increased to more than 75% when winding into the stator slots, which is 3% - 5% higher than that of copper wire, reducing the cross-sectional area of the stator slot, thus increasing the core area, and the core magnetic induction intensity B is reduced to about 81%. According to the above-mentioned core area increase factor, the core magnetic induction intensity drops by about 0.2T to 0.3T. Combining with the factor of frequency increase, the actual iron loss value increases by about 2.7 - 3.0W / Kg. The weight of the stator core of a 1.1kW synchronous reluctance motor is about 4Kg. The iron loss value increases by 0.27 - 0.3W / Kg × 4Kg = 11 - 12W. Compared with the 80W reduction in electrical loss, the increase in iron loss is less. Therefore, the comprehensive loss of the synchronous reluctance motor according to the embodiment is significantly reduced.

[0042] Figure 2 is a schematic cross-sectional view of the rotor of a synchronous reluctance motor according to an embodiment of the present invention.

[0043] Referring to Figure 2 , another example of the rotor of a synchronous reluctance motor is shown. The central portion 221 of each of the plurality of magnetic isolation slots 22 communicates with the extension portion 222, and an insulating separation material 223 is provided between the central portion 221 and the extension portion 222, so that the squirrel-cage coil 21 in each magnetic isolation slot can be divided into three segments to correspond to different phases of the stator magnetic field.

[0044] Figure 3 is a schematic cross-sectional view of the rotor of a synchronous reluctance motor according to an embodiment of the present invention.

[0045] Referring to Figure 3 , another example of the rotor of a synchronous reluctance motor is shown. Considering the productivity and cost of manufacturing the motor, the squirrel-cage coil can be separated by a magnetic bridge. For example, a magnetic bridge 224 is provided at the q-axis of the rotor in the central portion 221.

[0046] Figure 4 is a schematic cross-sectional view of the rotor of a synchronous reluctance motor according to an embodiment of the present invention.

[0047] Referring to Figure 4 , another example of the rotor of a synchronous reluctance motor is shown. Specifically, a magnetic bridge 224 is provided between the central portion 221 and the extension portion.

[0048] The above-mentioned insulating separation material or magnetic bridge for separating the conductors in the magnetic isolation slot into multiple segments in the present disclosure can be minimized in thickness along the extending direction of the magnetic isolation slot on the premise of meeting insulation and other requirements. For example, it can be less than the radial thickness of the magnetic isolation slot, and the position and number of the insulating separation material or magnetic bridge are not limited thereto.

[0049] In addition, permanent magnets can be used to divide the magnetic isolation slot 22 into two or more separated parts. The permanent magnets can be ferrite or neodymium iron boron materials. During the process of casting the squirrel-cage coil, there is a possibility of permanent magnet demagnetization. For this reason, it is proposed to first use unmagnetized magnetic materials and perform magnetization of the permanent magnets after the casting of the rotor squirrel-cage coil is completed. The efficiency of this permanent magnet assisted synchronous reluctance motor is better than that of a pure synchronous reluctance motor. According to the embodiment, the tangential dimension of the permanent magnet can be smaller than the tangential dimension of the central portion, so that the conductor size in the magnetic isolation slot increases.

[0050] The synchronous reluctance motor according to the embodiment can be started by using an asynchronous motor control strategy, so that it can equivalently replace the application scenarios of asynchronous motors and has significant advantages of being lightweight and highly efficient compared with traditional asynchronous motors. In addition, when the supply frequency of the synchronous reluctance motor is increased to twice the power frequency and the four-pole motor is operated as a two-pole motor, it can improve the performance degradation of the motor caused by using aluminum wire instead of copper wire and significantly improve the energy efficiency level of the motor.

[0051] The specific implementation methods of the present invention have been described in detail above. Although some embodiments have been shown and described, those skilled in the art should understand that the features of different embodiments may be modified, varied and further combined without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents. Such modifications, variations and further combinations should also be within the scope of protection of the claims of the present invention.

Claims

1. A synchronous reluctance motor, comprising a rotor and a stator arranged coaxially with a rotating shaft of the synchronous reluctance motor, characterized in that: The rotor comprises a rotor core, in which a plurality of magnetic isolation grooves are formed, which penetrate the rotor core in the axial direction and extend on a plane perpendicular to the axial direction, wherein each of the plurality of magnetic isolation grooves comprises a central portion extending in a tangential direction on the plane and extended portions located on both sides of the central portion and extending to near the outer edge of the rotor core, wherein the central portion and the extended portions are filled with conductive material, The stator comprises a stator core and a stator winding arranged in a stator slot of the stator core, wherein the stator winding is an aluminum wire winding, the power supply frequency of the stator winding is twice the industrial frequency, and the effective value of the electromotive force of the stator winding is the same as the industrial frequency power supply.

2. The synchronous reluctance motor according to claim 1, characterized in that: The synchronous reluctance motor has two or more pole pairs.

3. The synchronous reluctance motor according to claim 1, characterized in that: Compared to standard sizes, the number of turns of the stator winding is halved and the cross-sectional area per turn is doubled.

4. The synchronous reluctance motor according to claim 1, characterized in that: Compared to standard sizes, the stator teeth and / or stator yoke of the stator are increased in size and the cross-sectional area of ​​the stator slots is reduced to reduce iron losses.

5. The synchronous reluctance motor according to claim 1, characterized in that: Compared with the standard size, the cross-sectional area of ​​the stator slot and the number of winding turns remain unchanged, and the length of the motor core is reduced.

6. The synchronous reluctance motor according to claim 1, characterized in that: The central portion of each of the plurality of magnetic isolation grooves is in communication with the extending portion, wherein at least one of an insulating partition material, a permanent magnet, and a magnetic bridge is disposed in the central portion at a q-axis of the rotor.

7. The synchronous reluctance motor according to claim 1, characterized in that: The central portion of each of the plurality of magnetic isolation grooves is in communication with the extension portion, wherein an insulating separation material or a magnetic bridge is provided between the conductive material filled in the central portion and the conductive material filled in the extension portion.

8. A method for designing a synchronous reluctance motor, the synchronous reluctance motor comprising a rotor and a stator coaxially arranged with a rotating shaft of the synchronous reluctance motor, characterized in that: The rotor comprises a rotor core, in which a plurality of magnetic isolation grooves are formed, which penetrate the rotor core in the axial direction and extend on a plane perpendicular to the axial direction, wherein each of the plurality of magnetic isolation grooves comprises a central portion extending in a tangential direction on the plane and extended portions located on both sides of the central portion and extending to near the outer edge of the rotor core, wherein the central portion and the extended portions are filled with conductive material, The stator comprises a stator core and a stator winding arranged in a stator slot of the stator core, wherein the stator winding is an aluminum wire winding. The design method comprises: According to the equation E=4.44fN k Φ calculates the number of series turns N of each phase of the stator winding, where E is the induced electromotive force of the stator winding, f is the power supply frequency of the stator winding, Φ is the magnetic flux of the stator winding, k is the winding coefficient, the power supply frequency f is twice the power frequency, and the stator winding induced electromotive force E Same as industrial frequency power supply.

9. The method for designing a synchronous reluctance motor according to claim 8, characterized in that: The number of pole pairs of the synchronous reluctance motor is two or more, and compared with a standard size, the number of turns of the stator winding is halved and the cross-sectional area per turn is increased to twice.

10. The method for designing a synchronous reluctance motor according to claim 8, characterized in that: The number of pole pairs of the synchronous reluctance motor is two or more pairs, and the stator teeth and / or stator yoke of the stator are increased in size and the cross-sectional area of ​​the stator slots is reduced compared to standard sizes to reduce iron loss.

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