Synchronous reluctance motor

Abstract

The utility model provides a synchronous reluctance motor, 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 plurality of magnetic isolation grooves penetrate through the rotor iron core along 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 utility model relates to the field of motor, specifically, relate to a kind of asynchronous starting synchronous reluctance motor. BACKGROUND

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

[0003] Asynchronous starting synchronous reluctance motor is a high-efficiency synchronous reluctance motor without or with few permanent magnets, which has been widely valued in the fields of household appliances, automobiles, aerospace, etc. After adding permanent magnet auxiliary, synchronous reluctance motor has simple structure, optimized cost, good flux-weakening effect, significant energy-saving effect and is suitable for speed regulation in full-speed range of high, medium and low speed. Asynchronous starting synchronous reluctance motor is widely used, so a kind of asynchronous starting synchronous reluctance motor without or with few permanent magnets with compact structure, good reliability and high power density is needed.

[0004] Motor winding is generally made of copper wire. Compared with copper wire, aluminum wire has the advantages of light weight, low cost and abundant resources. On the other hand, it can also improve the lightweight of traditional motor. However, due to the restriction of electrical conductivity parameter, it is difficult to improve the efficiency of motor, and the heating problem of aluminum wire winding cannot be well solved. SUMMARY

[0005] To meet the increasing technical requirements, the embodiment of the present disclosure provides a synchronous reluctance motor, comprising a rotor and a stator coaxially arranged with a rotating shaft of the synchronous reluctance motor, the rotor comprising a rotor core, a plurality of magnetic isolation grooves are formed in the rotor core and extend through the rotor core in the axial direction and in a plane perpendicular to the axial direction, wherein each of the plurality of magnetic isolation grooves comprises a central portion extending in the tangential direction on the plane and an extension portion located on both sides of the central portion and extending to the outer edge of the rotor core, the central portion and the extension portion 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 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.

[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 size of the stator teeth and / or stator yoke of the stator is increased and the stator slot cross-sectional area is reduced to reduce the iron loss.

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

[0010] According to an embodiment, the central part of each of the plurality of magnetic isolation grooves is in communication with the extended part, wherein at least one of an insulating separation material, a permanent magnet and a magnetic bridge is arranged in the central part at the rotor q-axis.

[0011] According to an embodiment, the central part of each of the plurality of magnetic isolation grooves is in communication with the extended part, wherein an insulating separation material or a magnetic bridge is arranged between the electrically conductive material filled in the central part and the electrically conductive material filled in the extended part.

[0012] According to an embodiment, the synchronous reluctance motor can be started by adopting an asynchronous motor control strategy, so as to be able to replace an asynchronous motor in an application scene, and has a significant advantage of being lightweight and high in efficiency compared with a traditional asynchronous motor. In addition, when the power supply frequency of the synchronous reluctance motor is increased to twice the power frequency, the performance of the motor caused by using aluminum wire instead of copper wire is improved, and the motor energy efficiency grade is significantly improved. BRIEF DESCRIPTION OF DRAWINGS

[0013] The above and other aspects, features and advantages of the present disclosure will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0014] Figure 1 is a schematic cross-sectional view of a synchronous reluctance motor according to an embodiment of the present application;

[0015] Figure 2 is a schematic cross-sectional view of a rotor of a synchronous reluctance motor according to an embodiment of the present application;

[0016] Figure 3 is a schematic cross-sectional view of a rotor of a synchronous reluctance motor according to an embodiment of the present application;

[0017] Figure 4 is a schematic cross-sectional view of a rotor of a synchronous reluctance motor according to an embodiment of the present application. DETAILED DESCRIPTION

[0018] The following detailed description is presented in order to aid in understanding the methods, devices, and / or systems described herein. It will be appreciated, however, that various modifications, changes, and substitutions can be made to the methods, devices, and / or systems described herein without departing from the disclosure. For example, the order of the operations described herein is merely exemplary and the changes can be made to the order of the operations described herein, except that the operations that must occur in a specific order can not be changed. In addition, descriptions of features known to those skilled in the art can be omitted in order to improve clarity and conciseness. In order for those skilled in the art to better understand the present disclosure, specific embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0019] The Y series asynchronous motor specified in the national standard (GB) and its subsequent modified versions (Y2, Y3, YE3, and YX3) series asynchronous motors aim to improve the energy consumption level of the motor. 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 used as an equivalent replacement for the national standard asynchronous motor, and has a significant comparative advantage in efficiency compared to the traditional asynchronous motor.

[0020] The synchronous reluctance motor has low energy consumption and high cost performance, but the drive of the synchronous reluctance motor needs to be equipped with a V / F controller or a vector controller that can judge the position of the rotor to start according to the synchronous motor control strategy. In order to avoid the high cost of the controller, a squirrel cage coil (starting cage) can be arranged in the structure of the rotor of the synchronous reluctance motor to realize asynchronous starting, so that the synchronous reluctance motor can start using the asynchronous motor control strategy, thereby being able to replace the application scenario of the asynchronous motor.

[0021] In addition, the technical personnel in the field of motors have tried to replace copper wire with aluminum wire to achieve lightweight many times, but the electrical conductivity / resistivity parameters of aluminum wire restrict the current density of the winding, resulting in that the power and efficiency parameters cannot meet the demand. The resistivity of aluminum wire is generally 1.6 times or more than the resistivity of copper wire. In the conventional motor structure, when the motor winding current density of copper wire can be selected as 4-6 A / mm 2 , the motor winding current density of aluminum wire can only reach 2.4-3.6 A / mm 2 . In other words, under the same current density, the ratio of the cross-sectional area of the conductor of aluminum wire to that of copper wire needs to reach 1.6 times or more, but under the premise of the same slot type and stator slot cross-sectional area, there is not enough space to install a larger volume of aluminum wire.

[0022] To solve the above problems, considering that the inductance of the same electrical appliance varies with the frequency in different frequency power supply systems, the power and efficiency of an inductance type electrical appliance used for 50Hz frequency changes in a 60Hz frequency power supply system based on the change of inductance, thus, the disclosure proposes to increase the power supply frequency to twice the working frequency (100Hz), so that the inductance value of each turn of the motor winding is increased in proportion based on the multiple of the frequency. That is, the synchronous reluctance motor with increased power supply frequency attempts to obtain the same or higher magnetic flux with reduced number of turns and / or stator slot cross-sectional area, so that the stator slot cross-sectional area for setting the aluminum wire material can be more flexible. When the above improvements are combined, the power supply frequency is increased to twice the working frequency (100Hz), the conductor material properties can be appropriately reduced, and thus the performance degradation caused by using aluminum wire instead of copper wire is improved.

[0023] Moreover, since the synchronous reluctance motor can be started by using the asynchronous motor control strategy, the motor control system of the disclosure can be an open loop system, which can include a frequency multiplication device, which can be a simplified structure of the existing frequency conversion device, which can increase the motor operating frequency from the working frequency to the set frequency, and the output voltage value is unchanged, so that the motor speed is increased to 2 times the conventional speed based on the specific pole pair number, and the equivalent pole pair number is reduced by half. For example, when the working frequency is 50Hz, the power frequency is multiplied by 100Hz, so that the conventional speed of a four-pole motor is increased from 1500rpm to 3000rpm, which is equivalent to a two-pole motor.

[0024] According to an embodiment of the disclosure, an asynchronous starting synchronous reluctance motor is provided, which comprises a rotor and a stator arranged coaxially with the rotating shaft of the synchronous reluctance motor, the rotor comprises a rotor core, a plurality of magnetic isolation slots are formed in the rotor core and extend through the rotor core in the axial direction and extend in the tangential direction on a plane perpendicular to the axial direction, wherein each of the plurality of magnetic isolation slots comprises a central portion extending in the tangential direction on the plane and an extension portion located on both sides of the central portion and extending close to the outer edge of the rotor core, the central portion and the extension portion are filled with conductive material, the stator comprises a stator core and a stator winding arranged in the stator slot of the stator core, wherein the stator winding is an aluminum wire winding, and the power supply frequency is twice the working frequency and the winding electromotive force effective value is the same as the working frequency power supply, the asynchronous starting synchronous reluctance motor according to the embodiment has the significant advantages of light weight and high efficiency compared with the conventional asynchronous motor.

[0025] Figure 1 is a schematic cross-sectional view of a synchronous reluctance motor according to an embodiment of the present application.

[0026] Referring to Figure 1According to the embodiment, the synchronous reluctance motor includes a rotor 20 and a stator 10 arranged coaxially 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 arranged in the stator slot of the stator core, the stator winding 12 is an aluminum wire winding and the power supply frequency of the stator winding is twice the power frequency, and the stator winding electromotive force effective value is the same as the power frequency power supply. The rotor 20 of the synchronous reluctance motor is arranged in the structure of the synchronous reluctance motor without separately arranging the squirrel cage coil, the magnetic isolation slot 22 is arranged in the rotor core, and the aluminum is cast in the magnetic isolation slot 22 after the rotor core is formed by stacking the rotor punching sheet to form the squirrel cage coil 21. Specifically, a plurality of magnetic isolation slots 22 are formed in the rotor core and extend through the rotor core in the axial direction and extend in the plane perpendicular to the axial direction, for example, the number of layers of the magnetic isolation slot 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 in the tangential direction on the plane and an extension portion 222 located on both sides of the central portion 221 and extending close to the outer edge of the rotor core. The central portion 221 and the extension portion 222 are filled with conductive material. The central portion 221 extending in the tangential direction can mean that the central portion 221 has a straight shape in the plane and extends in the tangential direction perpendicular to the radial direction of the rotor, and can 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, the rotor 20 of the synchronous reluctance motor according to the embodiment does not separately arrange the squirrel cage structure outside the original magnetic isolation slot close to the outer edge of the rotor, but forms the squirrel cage coil 21 inside the magnetic isolation slot by the conductor material.

[0027] Due to the magnetic pole position of the motor stator winding, the rotation direction of the generated rotating magnetic field is opposite at both ends of each magnetic isolation slot, so the phase of the induced current at both ends of the magnetic isolation slot is different or even opposite. In order to avoid the generation of eddy current inside the conductor, an insulating area is arranged at the middle position of the magnetic isolation slot to divide the whole magnetic isolation slot into two or more sections, and the conductor in the single magnetic isolation slot is separated. According to one embodiment, referring to Figure 1 , the central portion 221 of each of the plurality of magnetic isolation slots 22 is in communication with the extension portion 222, wherein the central portion 221 is provided with an insulating separation material 223 at the rotor q-axis. The separation material of the squirrel cage coil can be asbestos board or other heat-resistant material, or other non-magnetic, insulating heat-resistant material.

[0028] The present disclosure adopts a four-pole or more pole motor, and the length of the motor stator and rotor magnetic circuit of the multi-pole pair (for example, two or more pole pairs) is significantly shorter than that of the few-pole pair (for example, one pole pair), which can significantly reduce the iron loss caused by high frequency.

[0029] When the supply frequency of the stator winding is twice the power frequency, the number of turns of the stator winding can be reduced by a corresponding proportion due to the increase in frequency while the voltage remains unchanged. The diameter of the high-resistivity aluminum wire (or copper-clad aluminum wire) can also be increased to replace the conventional copper wire to achieve the inductance (magnetic flux) required for motor operation. When the stator slot cross-sectional area remains unchanged, for example, the number of turns of the stator winding is halved and the cross-sectional area per turn is doubled compared to the standard size. The standard size can be the standard stator size list of the national standard Y series motor, but is not limited to this, and can also refer to the stator size of the conventional synchronous reluctance motor applicable to copper wire, or the preliminary calculation 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 per turn or improve the slot fill rate.

[0030] In the electromagnetic calculation process of an alternating current motor, the number of turns N of each phase of the motor winding in series is calculated according to the following formula 1:

[0031] E = 4.44fN k Φ (1)

[0032] wherein 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.

[0033] The voltage of a conventional V / F controller or vector controller is proportional to the change in the supply frequency f, but does not take into account the effect of the angular frequency on the number of turns of the winding.

[0034] It is proposed herein 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 turns N of each phase in series is inversely proportional to the supply frequency f of the stator winding; when the supply frequency f of the stator winding is doubled, the number of turns N of each phase in series is reduced by half.

[0035] According to formula 1, the disclosure proposes that the number of turns of the winding can be reduced by increasing the supply frequency. For example, increasing the power frequency of 50 Hz to 75 Hz as the supply frequency of the motor can reduce the number of turns of the winding by 1 / 3, and when the supply frequency of the motor is increased to 100 Hz, the number of turns of the winding can be halved. In a motor with a copper wire winding, according to formula 1, when the material properties remain unchanged, increasing the frequency supply can be used to reduce the number of turns of the winding and reduce the cross-sectional area of the stator slot, thereby increasing the stator tooth width and the stator yoke width; or, increasing the frequency supply can shorten the length of the stator and rotor core.

[0036] According to another embodiment, when the aluminum wire is used, the stator tooth and / or the stator yoke size is increased and the stator slot cross-sectional area is reduced to reduce the iron loss compared to the standard size. Since the frequency is doubled and the resistivity of aluminum material is only increased to about 1.6 times, the number of turns is halved (50%), the conductor cross-sectional area per turn is increased to 1.6 times, and the winding cross-sectional area in the stator slot is 1.6x50%, so the winding cross-sectional area is 80% of the standard size, and the stator slot cross-sectional area can be reduced by 20% for increasing the stator tooth width, and optionally, the stator yoke width can also be increased. According to Φ=BS, where B is the magnetic induction and S is the cross-sectional area of the stator tooth or yoke, E=4.44fN k BS, when the stator winding induced electromotive force E and the stator winding magnetic flux Φ are unchanged, increasing the stator tooth width and / or the yoke width can reduce the magnetic induction B, thereby significantly reducing the iron loss.

[0037] Since the frequency is doubled and the resistivity of aluminum material is only increased to about 1.6 times, the other parameters can be further adjusted when aluminum material is used but the stator slot cross-sectional area is unchanged, for example, compared to the standard size, the stator slot cross-sectional area and the number of turns of the winding are unchanged, and the motor core length is reduced, thereby reducing the core weight and the copper wire weight by 20% or more; optionally, the motor core outer diameter can also be reduced to achieve the effect of light weight, thereby achieving the miniaturization and light weight of the motor.

[0038] Embodiments of the present disclosure provide a design method of a synchronous reluctance motor, the synchronous reluctance motor comprising a rotor and a stator arranged coaxially with a rotating shaft of the synchronous reluctance motor, the rotor comprising a rotor core in which a plurality of flux barriers are formed to extend through the rotor core in an axial direction and extend in a plane perpendicular to the axial direction, wherein each of the plurality of flux barriers comprises a central portion extending in a tangential direction on the plane and extension portions located on both sides of the central portion and extending close to an outer edge of the rotor core, the central portion and the extension portions being filled with an electrically conductive material, the stator comprising 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 method comprising: calculating the number of turns N of each phase of the stator winding in series, wherein E is the induced electromotive force of the stator winding, f is the power supply frequency of the stator winding, and Φ is the magnetic flux of the stator winding, k Φcalculating the number of turns N of each phase of the stator winding in series, wherein E is the induced electromotive force of the stator winding, f is the power supply frequency of the stator winding, and Φ is the magnetic flux of the stator winding, k is the winding coefficient.

[0039] Table 1 below shows an embodiment based on a synchronous reluctance motor with a frame number of 90S-4, the size and performance parameters of the Y2 series 90S-4 prototype asynchronous motor and the improved synchronous reluctance motor are as follows in Table 1. Among them, the line voltage is 380V, the output power is 1500W, and the rated speed is 3000rpm.

[0040] Table 1

[0041]

[0042] Referring to Table 1, the synchronous reluctance motor according to the embodiment adopts aluminum wire material and improves the power supply frequency to twice, so that the four-pole motor can be operated as a two-pole motor, and the efficiency, cost and light weight are significantly improved.

[0043] In terms of loss, it generally includes resistance loss and iron loss. The resistance loss is the loss caused by the current thermal effect of the winding, which becomes copper loss in a conventional motor.

[0044] The resistance loss of the synchronous reluctance motor mainly manifests as direct current loss, and the alternating current loss can be ignored. When the power supply frequency is improved to 100 Hz, and other parameters such as voltage, magnetic induction intensity and core cross-sectional area remain unchanged, the winding turns are halved, so that the direct current resistance loss is halved, and considering the temperature rise and other factors, the actual resistance loss slightly increases compared with the calculated value. For example, the resistance loss of a 1.1 kW synchronous reluctance motor is reduced by about 80 W.

[0045] In terms of iron loss, under the same current carrying capacity, the volume of aluminum wire material is about 1.63 times that of copper wire. When the power supply frequency is improved to twice, the volume of aluminum wire material can be halved, and because the hardness of aluminum wire material is softer than that of copper wire material, the slot fill rate can be improved to more than 75% when the wire is lowered into the stator slot, which is 3% to 5% higher than the slot fill rate of copper wire material, so that the cross-sectional area of the stator slot is reduced, thereby 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 is reduced by about 0.2 T to 0.3 T, and combined with the factor of frequency improvement, the actual iron loss value increases by about 2.7 to 3.0 W / Kg. The weight of the stator core of a 1.1 kW synchronous reluctance motor is about 4 Kg. The iron loss value increases by 0.27 to 0.3 W / Kg x 4 Kg = 11 to 12 W, which is less than the decrease of 80 W in the electric loss. Therefore, the comprehensive loss of the synchronous reluctance motor according to the embodiment is significantly reduced.

[0046] Figure 2 is a schematic cross-sectional view of a rotor of a synchronous reluctance motor according to an embodiment of the present application.

[0047] Referring to Figure 2 , another example of a rotor of a synchronous reluctance motor is shown. The central part 221 of each of the plurality of magnetic isolation grooves 22 is in communication with the extension part 222, wherein an insulating separation material 223 is arranged between the central part 221 and the extension part 222, so that the squirrel cage coil 21 in each magnetic isolation groove can be divided into three sections to correspond to different phases of the stator magnetic field.

[0048] Figure 3is a schematic cross-sectional view of a rotor of a synchronous reluctance motor according to an embodiment of the present application.

[0049] Referring to Figure 3 Another example of a 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 in the central portion 221 at the rotor q-axis.

[0050] Figure 4 is a schematic cross-sectional view of a rotor of a synchronous reluctance motor according to an embodiment of the present application.

[0051] Referring to Figure 4 Another example of a rotor of a synchronous reluctance motor is shown, specifically, a magnetic bridge 224 is provided between the central portion 221 and the extended portion.

[0052] The above-mentioned insulation separation material or magnetic bridge for separating the conductors in the flux barrier into multiple segments in the present disclosure can be minimized in thickness along the extension direction of the flux barrier under the premise of meeting the requirements of insulation and the like, for example, can be less than the radial thickness of the flux barrier, and the position and number of the insulation separation material or magnetic bridge are not limited thereto.

[0053] In addition, the flux barrier 22 can be separated into two or more separated portions using a permanent magnet, which can be a ferrite or a neodymium-iron-boron material. During the process of pouring the squirrel cage coil, there is a possibility that the permanent magnet will demagnetize. For this reason, it is proposed that a non-magnetized magnetic material can be used first, and the magnetization of the permanent magnet is performed after the pouring of the rotor squirrel cage coil is completed. The efficiency of such a permanent magnet assisted synchronous reluctance motor is better than that of a pure synchronous reluctance motor. According to an embodiment, the tangential size of the permanent magnet can be less than the tangential size of the central portion, so that the size of the conductors in the flux barrier is increased.

[0054] The synchronous reluctance motor according to the embodiment can be started using an asynchronous motor control strategy, so as to be able to replace an asynchronous motor in an application scenario, and has the significant advantages of lightweight and high efficiency compared with a traditional asynchronous motor. In addition, when the power supply frequency of the synchronous reluctance motor is increased to twice the power frequency, the synchronous reluctance motor operates as a four-pole motor, which can improve the performance degradation of the motor caused by using aluminum wire instead of copper wire, and significantly improve the motor energy efficiency grade.

[0055] The specific embodiments of the present application 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 can be modified and changed and further combined without departing from the principles and spirits of the present application defined by the claims and their equivalents, and these modifications, changes and further combinations should also be within the protection scope of the claims of the present application.

Claims

1. A synchronous reluctance motor comprising a rotor and a stator arranged coaxially with a rotation axis of the synchronous reluctance motor, characterized in that, the rotor comprises a rotor core in which a plurality of flux barriers are formed which penetrate the rotor core in an axial direction and extend in a plane perpendicular to the axial direction, wherein each of the plurality of flux barriers comprises a central portion extending in a tangential direction on the plane and extension portions located on both sides of the central portion and extending to an outer edge of the rotor core, the central portion and the extension portions being filled with an electrically 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 stator winding is supplied with a frequency of twice the power frequency, and the stator winding electromotive force effective value is the same as the power frequency.

2. The synchronous reluctance machine of claim 1, wherein, The synchronous reluctance motor has two or more pairs of pole pairs.

3. The synchronous reluctance machine of claim 1, wherein, Compared with the standard size, the number of turns of the stator winding is halved and the cross-sectional area per turn is doubled.

4. The synchronous reluctance machine of claim 1, wherein, Compared with the standard size, the size of the stator teeth and / or the stator yoke of the stator is increased and the cross-sectional area of the stator slot is reduced to reduce the iron loss.

5. The synchronous reluctance machine of claim 1, wherein, Compared with the standard size, the cross-sectional area of the stator slot and the number of turns of the winding are unchanged, and the length of the motor core is reduced.

6. The synchronous reluctance machine of claim 1, wherein, The central portion of each of the plurality of flux barriers is in communication with the extension portion, wherein at least one of an insulating separation material, a permanent magnet and a magnetic bridge is arranged in the central portion at the rotor q-axis.

7. The synchronous reluctance machine of claim 1, wherein, The central portion of each of the plurality of flux barriers is in communication with the extension portion, wherein an insulating separation material or a magnetic bridge is arranged between the electrically conductive material filled in the central portion and the electrically conductive material filled in the extension portion.

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