Reluctance type electro-magnetic synchronous motor

Abstract

The invention discloses a reluctance type electrically excited synchronous motor, which comprises a base, an armature core, an armature winding, a rotor core, an excitation winding, a rotating shaft and an excitation power supply device, the rotor core comprises a plurality of rotor punching sheets, the circumference of each rotor punching sheet is provided with multi-order excitation winding grooves, rotor teeth are formed between notches of every two adjacent excitation winding grooves, a magnetic barrier is arranged between the bottoms of every two excitation winding grooves of the same order, magnetic bridges are formed between the ends of the magnetic barriers and the bottoms of the excitation winding grooves, and conducting bars are formed between every two adjacent magnetic barriers. According to the reluctance type electro-magnetic synchronous motor, the salient pole rate xi of the rotor can be easily increased to more than 5; when the excitation winding is installed, the rotor does not need to be rotated by a machine tool, and the pre-manufactured winding can be embedded into the excitation winding groove turn by turn; the distributed excitation winding is good in heat dissipation performance, and heat accumulation of a centralized winding is avoided; multi-order distributed excitation enables multi-order magnetic potential levels to be formed on the rotor, and the rotor has excellent distribution characteristics.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and in particular to a reluctance electric excitation synchronous motor. Background Art

[0002] Existing electric excitation synchronous motors are divided into salient pole type and non-salient pole type. The excitation winding of the non-salient pole electric excitation synchronous motor is a distributed winding embedded in the slots on the surface of the rotor core. The magnetic potential on the rotor has good distribution characteristics. However, the rotor core of the non-salient pole electric excitation synchronous motor is a solid structure made of soft magnetic material. The magnetic flux can be conducted unrestricted in any direction and cannot form a different direct axis inductance L. d With quadrature axis inductance L q , L d / L q The ratio of the salient pole ratio ξ is equal to or slightly greater than 1, and it cannot generate reluctance torque T when used as a motor. rel , mainly used for generators; while the L of the salient pole electric excitation synchronous motor rotor d Greater than L q , that is, the salient pole ratio ξ is greater than 1. This rotor can make the motor generate reluctance torque T rel .

[0003] The L of the existing salient pole electric excitation synchronous motor rotor d With L q Although the difference is significant, it is not very large. Therefore, the reluctance torque T in the motor torque under the driving condition is rel The proportion is relatively small, and the output electromagnetic torque T em A large part of the excitation torque T ee The reason that restricts the improvement of the salient pole ratio ξ of the existing salient pole type electric excitation synchronous motor rotor is the structure of the rotor core. In order to facilitate the excitation on the rotor core, the rotor core of the salient pole type electric excitation synchronous motor is designed to have a corresponding number of pole bodies, and pole shoes are arranged on both sides of the top of the pole body. The excitation winding is a concentrated winding wound on the pole body. There is less soft magnetic material distributed in the area where the quadrature axis q between two adjacent magnetic poles is located, forming a lower quadrature axis inductance L. q On the other hand, in order to obtain a sufficient pole arc angle, the pole body and the pole shoes on both sides of the pole body top jointly form a wide pole surface. The magnetic flux can still be conducted along the cross-axis magnetic circuit through the soft magnetic material below the pole surface, thereby limiting the cross-axis inductance L q Further reduction results in the salient pole ratio ξ of the existing salient pole electrically excited synchronous motor rotor being generally between 2.5 and 4 and being difficult to increase further.

[0004] In addition, the excitation winding of the existing salient pole electric excitation synchronous motor is a centralized winding, that is, each magnetic pole is only provided with a set of electromagnetic coils wound on the pole body. Such a structure also has the following three disadvantages: first, it is difficult to wind the wire. Because of the existence of the pole shoe, if the centralized excitation winding that has been wound in advance cannot pass over the pole shoe and be wrapped around the pole body, the rotor core must be rotated as a whole before winding. Usually, when winding, the rotor core that has been inserted into the shaft needs to be clamped with a machine tool to rotate slowly, and then the electromagnetic wire is manually passed to a fixed direction perpendicular to the coil arrangement surface for a long time. In order to keep the winding flat, the first few layers are wound through The rotor core inserted into the shaft needs to be carefully adjusted and aligned every time it rotates 90° to the corner. If the arrangement is messed up, it needs to be rewound again. In order to avoid fatal injuries, the operator's head needs to rhythmically avoid the long extended shaft during the long winding process. This has extremely strict requirements on the operator's proficiency, physical fitness and safety awareness. The winding process is time-consuming, labor-intensive and dangerous. The second disadvantage is that it is not conducive to heat dissipation. The reason is that a single electromagnetic coil is very easy to accumulate heat, especially in the deep part of the coil. The third disadvantage is the poor distribution characteristics, which is determined by the characteristics of centralized windings. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a reluctance electric excitation synchronous motor which is easy to assemble, avoids heat accumulation in concentrated windings, and has excellent distribution characteristics.

[0006] The technical solution adopted by the present invention is:

[0007] A reluctance type electric excitation synchronous motor comprises a machine base, an armature core, an armature winding, a rotor core, an excitation winding, a rotating shaft and an excitation power supply device; the armature core is arranged in the machine base, the armature winding is arranged on the armature core, the rotor core is arranged in the armature core chamber, an air gap is left between the rotor core and the armature core, and an axial hole is arranged in the center of the rotor core; the rotating shaft is arranged in the central axial hole of the rotor core; the excitation power supply device is arranged on the rotating shaft;

[0008] The rotor core comprises a plurality of rotor punchings, which are circular sheets with an axial hole at the center. The plurality of rotor punchings are stacked and arranged on a rotating shaft in sequence through the axial hole at the center to form a cylindrical rotor core; multi-order excitation winding slots are symmetrically arranged on both sides of the circumference of the rotor punchings along the q-axis, the outer end of each excitation winding slot extends to the circumference to form a slot, and rotor teeth are formed between the slots of two adjacent excitation winding slots, a magnetic barrier is arranged between the bottoms of two excitation winding slots of the same order, a magnetic bridge is formed between the end of the magnetic barrier and the bottom of the excitation winding slot, and a conductive bar is formed between two adjacent magnetic barriers of the order; the excitation windings are respectively arranged in the excitation winding slots of the same order, and the excitation winding is a distributed winding.

[0009] Specifically, the excitation order L of the multi-order excitation winding slots ise The value range is 2-7. The excitation winding slot adjacent to the d-axis is the first-order excitation winding slot. According to the value of the excitation order, from the d-axis to the q-axis, it is the first to the Lth order. e Step field winding slots.

[0010] More specifically, the reluctance type electrically excited synchronous motor according to claim 1 is characterized in that: the number Q of the excitation winding slots is e The number of motor pole pairs P and the excitation order L of the excitation winding slots e The relationship is:

[0011] Q e =2P×2L e .

[0012] More specifically, the rotor teeth are provided with a plurality of magnetic potential levels of order L. f , magnetic potential level order L f and excitation order L e The relationship is:

[0013] L f =2L e +1.

[0014] Specifically, the rotor teeth at the d-axis position are polar axis teeth, and the rotor teeth at the q-axis position are inter-polar teeth.

[0015] Specifically, the magnetic barrier is arranged in a single-segment, two-segment or three-segment type, and magnetic bridges are formed between each segment of the magnetic barrier.

[0016] Specifically, the magnetic potential axis F of the excitation winding f Coincident with the d-axis or coincident with the q-axis.

[0017] Specifically, the slot opening of the field winding slot is open or half-open.

[0018] Specifically, the plurality of rotor punching sheets are stacked in sequence on the rotating shaft to form a rotor core with straight poles or oblique poles.

[0019] Due to the adoption of the above-mentioned technical solution, the present invention has the following advantages:

[0020] The reluctance electric excitation synchronous motor of the present invention can easily increase the salient pole ratio ξ of the rotor to more than 5; when installing the excitation winding, there is no need to use a machine tool to rotate the rotor, and the pre-made winding can be embedded in the excitation winding slot turn by turn; the distributed excitation winding has good heat dissipation performance and avoids heat accumulation in the centralized winding; the multi-stage distributed excitation forms multi-stage magnetic potential levels on the rotor, which has excellent distribution characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1It is the basic structural diagram of a reluctance electrically excited synchronous motor.

[0022] Figure 2 It is an isometric view of a rotor with parallel field winding slots and d-axis magnetic potential winding.

[0023] Figure 3 is the excitation order L e Schematic diagram of rotor punching with parallel field winding slots = 3.

[0024] Figure 4 yes Figure 3 Schematic diagram of the excitation current direction of the d-axis magnetic potential winding method of the structural rotor.

[0025] Figure 5 It is a schematic diagram of the direction of the excitation current for the parallel excitation winding slots and q-axis magnetic potential winding method.

[0026] Figure 6 is the excitation order L e Schematic diagram of the rotor expansion using the d-axis magnetic potential winding method with a value of =3 as an example.

[0027] Figure 7 It is the expansion diagram of the excitation winding of the d-axis magnetic potential winding method.

[0028] Figure 8 It is the expansion diagram of the excitation winding of the q-axis magnetic potential winding method.

[0029] Fig. 9 It is an isometric view of a rotor with parallel field winding slots and q-axis magnetic potential winding.

[0030] Fig.10 The number of pole pairs P = 1, the excitation order L e Schematic diagram of rotor punching with =5.

[0031] Fig.11 yes Fig.10 Isometric view of a rotor with a rotor lamination structure.

[0032] Fig.12 is the excitation order L e Schematic diagram of the rotor punching of the radial excitation winding slot with =3.

[0033] Fig.13 yes Fig.12 Isometric view of a rotor with a rotor lamination structure.

[0034] Fig.14 is the excitation order L e Schematic diagram of the rotor punching with an angled field winding slot of =3.

[0035] Fig.15 yes Fig.14 Isometric view of a rotor with a rotor lamination structure.

[0036] Fig.16 It is a partial schematic diagram of the skew-pole rotor core.

[0037] Fig.17 This is a partial view of a rotor punching with a pole pair number P=3 and an open structure for the slot openings of the excitation winding.

[0038] In the figure: 1-rotor core, 11-excitation winding slot, 111-first-order excitation winding slot, 112-second-order excitation winding slot, 113-third-order excitation winding slot, 12-rotor tooth, 12d-pole axis tooth, 122-second-order tooth, 123-third-order tooth, 12q-inter-pole tooth, 13-magnetic barrier, 14-conductor bar, 15-slot, 16-magnetic bridge, 17-shaft hole, 2-excitation winding, 21-first-order excitation winding, 22-second-order excitation winding, 23-third-order excitation winding, 24-fourth-order excitation winding, 25-fifth-order excitation winding, 3-machine base, 41-armature core, 42-armature winding, 5-rotating shaft, 6-excitation power supply device, 7-slot wedge, 8-slot paper, 9-air gap, d-direct axis, q-quadrature axis, F f -Magnetic potential axis. DETAILED DESCRIPTION

[0039] The present invention will be further explained below in conjunction with the accompanying drawings and embodiments, which should not be used to limit the protection scope of the present invention. The purpose of disclosing the present invention is to protect all technical improvements within the scope of the present invention.

[0040] like Figure 1 As shown, the structure of the reluctance type electric excitation synchronous motor of the present invention includes a base 3, an armature core 41, an armature winding 42, a rotor core 1, an excitation winding 2, a rotating shaft 5 and an excitation power supply device 6; the armature core 41 is arranged in the base 3, the armature winding 42 is arranged on the armature core, the rotor core 1 is arranged in the bore of the armature core 41, and an air gap 9 is left between the rotor core 1 and the armature core 41; the rotor core 1 is provided with an axial hole 17 at the center, and the rotating shaft 5 is arranged in the rotor core 1. The excitation power supply device 6 is arranged on the rotating shaft 5; different from the prior art salient pole electric excitation synchronous motor, the cross section of the rotor core 1 of the reluctance electric excitation synchronous motor is circular, because the rotor core 1 includes a plurality of rotor punchings, the rotor punchings are circular sheets, and an axial hole 17 is arranged in the center. The plurality of rotor punchings are sequentially stacked and arranged on the rotating shaft 5 through the central axial hole 17 to form a cylindrical rotor core 1; multi-stage excitation winding slots 11 are symmetrically arranged on both sides of the q axis on the circumferential surface of the rotor punchings, such as Figure 3 As shown, when the excitation order L e When 3 is taken, the excitation winding slots 11 are divided into the first-order excitation winding slots 111 closest to the d-axis according to their positions on the d\q coordinate system, and then the second-order excitation winding slots 112 and the third-order excitation winding slots 113 in the q-axis direction; the excitation winding slots 11 between the same magnetic pole and the same order can be distributed radially, such as Fig.12 , 13 As shown, it can also be set as a parallel distribution, such as Figure 2 , 3 , 10, 11; or with the d axis as the center line, the excitation winding slots 11 on both sides are arranged at an angle. For a 4-pole motor rotor, the angled excitation winding slots can save space, so that a larger diameter shaft hole 17 can be set at the center of the rotor core 1 cross section, such as Fig.14 , 15 As shown; for a 2-pole motor rotor, using parallel field winding slots can save more space, such as Fig.10 , 11 shown.

[0041] In order to facilitate the installation of the excitation winding 2, a notch 15 is formed on the circumference of the outer end of each excitation winding slot 11. The notch 15 can be half-open, such as Figure 2 , 3 As shown, it can also be an opening, such as Fig.17 As shown; a rotor tooth 12 is formed between the slots 15 of two adjacent excitation winding slots 11, and the rotor tooth 12 is divided into a polar axis tooth 12d on the d-axis position, a second-order tooth 122, a third-order tooth 123 and an inter-polar tooth 12q on the q-axis position according to the position on the d\q coordinate system.

[0042] A magnetic barrier 13 is provided between the bottoms of the excitation winding slots 11 of the same order between adjacent magnetic poles on both sides of the q axis, and a magnetic bridge 16 is formed between the magnetic barrier 13 and the bottom of the excitation winding slot 11. In order to meet the mechanical strength of the iron core, the longer magnetic barrier 13 can be divided into 2 or 3 sections, and a magnetic bridge 16 is also formed between each section. Fig.17 As shown; a conductive bar 14 is formed between adjacent magnetic barriers 13; the rotor core 1 is a rotor core in which a plurality of rotor punchings are sequentially stacked and arranged on a rotating shaft to form a straight pole or a skewed pole; under the same other settings, the skewed pole rotor has a lower tooth harmonic content, pulsating torque and cogging torque than the straight pole rotor; the rotor skew angle can be set to the slot pitch angle α of the matching armature core 41 or larger, such as Fig.16 shown.

[0043] like Figure 2 , 9 As shown in , 17, the pole number 2P of the reluctance electric excitation synchronous motor can be an even number such as 2, 4, 6, etc., that is, the number of motor pole pairs P is a non-zero natural number.

[0044] Since the excitation winding slots 11 are multi-stage, that is, a distributed excitation winding 2 is arranged on each magnetic pole of the rotor core 1 to achieve a multi-level magnetic potential effect, the excitation winding 2 is respectively embedded in the multi-stage excitation winding slots 11, such as Figure 2 , 4, 5, 6, 7, 8; Each order of the excitation winding 2 of each pole requires an excitation winding slot 11 on each side for placement, so the number of excitation winding slots 11 Q e The number of motor pole pairs P and excitation order L e The relationship is Q e =2P×2L e ; When installing the excitation winding 2 of the reluctance type electrically excited synchronous motor, there is no need to use a machine tool to rotate the rotor, and the pre-made winding can be embedded in the excitation winding slot 11 turn by turn; the armature winding 42 is a distributed winding, and the best is a symmetrical concentric winding, such as Figure 7 , 8 As shown; slot paper 8 can be placed in the excitation winding slot 11 for insulation between the rotor core 1 and the excitation winding 2, the inner side of the slot 15 is provided with a slot wedge 7 or sealed with a curable fluid material, the end of the excitation winding 2 can be shaped and tied, and the installation method is the same as the stator winding of a conventional AC motor, such as Figure 2 , 9 , 11, 13, and 15; the distributed excitation winding 2 has good heat dissipation performance, avoiding heat accumulation in the centralized winding; the distributed excitation forms a multi-order magnetic potential level on the rotor, which has excellent distribution characteristics.

[0045] Through multi-stage excitation, multiple magnetic potential levels of order L are formed on the rotor teeth 12. f , magnetic potential level order L f and excitation order L e The relationship is: L f =2L e +1; with 3rd order excitation, i.e. L e =3 as an example, Figure 6 As shown, the excitation generates a total of 7 magnetic potential levels L3, L2, L1, L0, -L1, -L2 and -L3 on the rotor teeth 12. f , which includes 3 positive magnetic potential levels, a neutral magnetic potential level L0 and 3 negative magnetic potential levels.

[0046] There are two ways to wind the field winding 2. The magnetic potential axis F f That is, the d axis can be taken as the center, such as Figure 2 , 4 , 7, or the q axis can be used as the center, such as Figure 5 , 8 , as shown in Figure 9; the direction of the magnetic potential formed on the rotor of the d-axis magnetic potential winding method is consistent with that of the salient pole electrically excited synchronous motor; the direction of the magnetic potential formed on the rotor of the q-axis magnetic potential winding method is consistent with that of the permanent magnet assisted synchronous reluctance motor PM-SynRM. Therefore, the control method of the reluctance electrically excited synchronous motor using the q-axis magnetic potential winding method is also consistent with that of the permanent magnet assisted synchronous reluctance motor PM-SynRM. The electromagnetic torque T of the motor em Expressed as:

[0047]

[0048] Where λ ee is the electric excitation flux, and is the permanent magnet flux of the PM-SynRM rotor pm has the same effect; and the electric excitation torque T ee Expressed as:

[0049]

[0050] and reluctance torque T rel Expressed as:

[0051]

[0052] The rotor axis view of the q-axis magnetic potential winding method is as follows Fig. 9 shown.

[0053] The excitation winding 2 can be connected in series, in parallel or in a combination of series and parallel according to the voltage of the DC excitation power supply and the diameter of the electromagnetic wire used in the excitation winding 2. Figure 8 The figure shows the development diagram of the rotor winding of the q-axis magnetic potential winding method; the current direction of the excitation winding 2 is defined as: providing two magnetic potential axes F with an electrical angle of 180° apart f The current direction of opposite polarity, that is, the polarity of adjacent magnetic poles is opposite, such as Figure 4 , 5 , 7, and 8.

[0054] The excitation winding 2 of the reluctance type electric excitation synchronous motor is multi-stage. Taking the d-axis magnetic potential winding method as an example, the rotor tooth 12 located on the d-axis obtains the most ampere-turns, and the rotor tooth 12 located on the d-axis obtains the least ampere-turns, thereby forming a magnetic potential level distribution that decreases from the d-axis to the d-axis. The multi-stage excitation can also constrain the magnetic flux distribution, and also has a distribution effect of decreasing density from the d-axis to the q-axis; the multi-stage excitation makes all the magnetic bridges 16 on the rotor core 1 and the areas around the slots 15 fully magnetically saturated, reduces the leakage flux between the bars 14, and makes L q Further reduce; even if the excitation order L e Only 2, the rotor salient pole ratio ξ can also be increased to more than 5, which is higher than the upper limit of the salient pole electric excitation synchronous motor. If the excitation order L is set e is 3 or 4, the salient pole ratio ξ can be increased to above 7; but if the excitation order L e If the salient pole ratio ξ is increased continuously, the excitation order L is set to e A value between 2 and 7 is appropriate.

[0055] The reluctance electric excitation synchronous motor also has excellent self-starting performance, which is the same as the starting characteristics of the wound-rotor asynchronous motor. Distributed windings are embedded in the slots on the surface of the rotor core 1. When the motor is started, the armature winding 42 is connected to the alternating current, and at the same time, the two input ends of the excitation winding 2 are short-circuited through the excitation power supply device 6 to generate a strong electromagnetic torque to start the motor. If a resistor box is used in parallel with the excitation winding 2 instead of short-circuiting it, the impact on the power grid can be reduced with a lower starting current, and the resistance value can be adjusted to control the starting torque and starting time.

[0056] The reluctance electric excitation synchronous motor can also be used as a synchronous reluctance motor when there is no excitation current. ee The motor can select the mode among no excitation, under excitation, normal excitation and over excitation, and obtain the required power factor angle by adjusting the excitation current. and back EMF.

[0057] The parts not described in detail in this invention are prior art.

[0058] The embodiments selected herein for the purpose of disclosing the invention are currently considered to be suitable, but it should be understood that the invention is intended to include all changes and modifications of the embodiments that fall within the scope of the concept and invention.

Claims

1. A reluctance type electrically excited synchronous motor, comprising a base, an armature core, an armature winding, a rotor core, an excitation winding, a rotating shaft and an excitation power supply device; the armature core is arranged in the base, the armature winding is arranged on the armature core, the rotor core is arranged in the armature core chamber, an air gap is left between the rotor core and the armature core, and an axial hole is arranged in the center of the rotor core; the rotating shaft is arranged in the central axial hole of the rotor core; the excitation power supply device is arranged on the rotating shaft; the characteristics are: The rotor core comprises a plurality of rotor punchings, which are circular sheets with an axial hole in the center. The plurality of rotor punchings are stacked and arranged on a rotating shaft in sequence through the axial hole in the center to form a cylindrical rotor core; multi-order excitation winding slots are symmetrically arranged on both sides of the circumference of the rotor punchings along the q-axis, the outer end of each excitation winding slot extends to the circumference to form a slot, a rotor tooth is formed between the slots of two adjacent excitation winding slots, a magnetic barrier is arranged between the bottoms of two excitation winding slots of the same order, a magnetic bridge is formed between the end of the magnetic barrier and the bottom of the excitation winding slot, and a conductive bar is formed between two adjacent magnetic barriers of the order; the excitation windings are respectively arranged in the excitation winding slots of the same order, and the excitation winding is a distributed winding.

2. The reluctance type electrically excited synchronous motor according to claim 1, characterized in that: The excitation order L of the multi-order excitation winding slots e The value range is 2-7. The excitation winding slot adjacent to the d-axis is the first-order excitation winding slot. According to the value of the excitation order, from the d-axis to the q-axis, it is the first to the Lth order. e Step field winding slots.

3. The reluctance type electrically excited synchronous motor according to claim 2, characterized in that: The number of field winding slots Q e The number of motor pole pairs P and the excitation order L of the excitation winding slots e The relationship is: Q e =2P×2L e 。 4. The reluctance type electrically excited synchronous motor according to claim 2, characterized in that: The rotor teeth form a plurality of magnetic potential levels of order L f , magnetic potential level order L f and excitation order L e The relationship is: L f =2L e +1.

5. The reluctance type electrically excited synchronous motor according to claim 1, characterized in that: The rotor teeth at the d-axis position are polar axis teeth, and the rotor teeth at the q-axis position are inter-polar teeth.

6. The reluctance type electrically excited synchronous motor according to claim 1, characterized in that: The magnetic barrier is arranged in a single-stage, two-stage or three-stage manner, and magnetic bridges are formed between the magnetic barriers of each stage.

7. The reluctance type electrically excited synchronous motor according to claim 1, characterized in that: The magnetic potential axis F of the excitation winding f Coincident with the d-axis or coincident with the q-axis.

8. The reluctance type electrically excited synchronous motor according to claim 1, characterized in that: The slot opening of the field winding slot is open or half-open.

9. The reluctance type electrically excited synchronous motor according to claim 1, characterized in that: The plurality of rotor punching sheets are sequentially stacked and arranged on the rotating shaft to form a rotor core with straight poles or oblique poles.

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