JP2020174509A - Radial air gap type variable magnetic flux field type synchronous machine - Google Patents

Abstract

To solve the problem in which, a variable magnetic flux field type synchronous machine, which becomes an electric motor with large torque at start-up and high efficiency at high speed when used in an electric vehicle, and which becomes a generator capable of operating for many hours at a maximum power point of a wind turbine, which fluctuates as the wind speed changes when used for wind power generation, has major issues of reducing an excitation loss and reducing the manufacturing cost since it requires a DC exciter.SOLUTION: Provided is an inner rotor type variable magnetic flux field type synchronous machine having a configuration in which a field is divided into two in a direction of a rotary shaft, a DC exciting coil is placed in a space near the rotary shaft made of ferromagnet by cutting a central part, a support member of the coil is positioned in the shaft direction by a protrusion provided in a central inner diameter of an armature core and is bonded to an inner diameter of the armature core in the vicinity, adjacent field magnetic poles have the same polarity as a combination of a permanent magnet and an exciting electromagnet, and an outer cover is a non-magnetic light metal with excellent heat dissipation.SELECTED DRAWING: Figure 1

Description

The present invention relates to a radial air gap type variable magnetic flux field type synchronous generator and a synchronous motor.

When used as a generator for wind power generation, the variable magnetic flux field type synchronous machine can be easily controlled so that it can generate power near the maximum output of the wind turbine according to the wind speed, and when used as a drive motor for an electric vehicle, it is high at the time of starting. The variable magnetic field field type synchronous machine is a highly functional energy conversion machine, such as an electric motor that generates torque and can achieve high speed while maintaining high efficiency at high speed. In particular, the radial air gap type synchronous machine is superior to the axial air gap type synchronous machine in that it has few side effects of magnetic attraction, and its performance quality and economic efficiency are desired to be improved.

JP-A-2017-93274 JP 2011-67048 JP-A-2004-72827 JP-A-2004-350414 JP 2000-41367 JP-A-6-351206

In the axial air gap type synchronous machine, a large magnetic attractive force and repulsive force act in the direction of the rotation axis, and a large force is applied to components such as the field magnet, armature, bearing, and jacket, so the strength of these components can be increased. It is inferior in economic efficiency. On the other hand, in the radial air gap type synchronous machine, the magnetic attractive force and the repulsive force act in the radial direction, so that the synthetic force is canceled and there is no such adverse effect. Therefore, it is an issue to create a radial air gap type variable magnetic flux field type synchronous machine having a low-cost and high-performance DC exciter.

The technique of Patent Document 1 has a drawback that the size is increased because the exciting iron core is provided and the excitation loss is increased because two air gaps are generated between the field and the field core.

Similar to the technique of Patent Document 1, the technique of Patent Document 2 is said to have a large size because it is provided with an exciting iron core, and also has a large excitation loss because two air gaps are generated between the technique and the field core. There are drawbacks.

In the technique of Patent Document 3, since it is necessary to use a ferromagnetic material for the material of the motor case and the lid, heat dissipation becomes poor, the temperature of the winding rises, and the overall size increases, resulting in quality. And there is a risk that economic efficiency will be impaired.

Since the technique of Patent Document 4 uses an exciting core, an air gap is required between the field core and the magnetic flux, so that the exciting magnetic flux is reduced, the space of the exciting core is increased, or the field core is made of iron. Since it is surrounded by the outer cover of the ferromagnetic material, heat dissipation is poor, the temperature rise of the armature coil is high, and the armature coil is exposed to the outside air, which has the disadvantage of lowering reliability. ..

The technique of Patent Document 5 is not an inner rotor type but an outer rotor type, and has a drawback that a large exciting iron core for supporting the armature is required and the cost is high.

In the technique of Patent Document 6, the peripheral length of the exciting coil becomes long, the copper loss increases, the wire diameter becomes thick, and the armature core is divided into two, so that the manufacturing cost increases. There is a drawback that it does.

In order to improve the above-mentioned drawbacks of the technology, the following are the basic issues.
(1) The DC exciting magnetic circuit does not use an exciting iron core, the air gap in the magnetic circuit can be reduced, the excitation loss can be reduced, and the size of the equipment can be reduced.
(2) The field means that a magnetic circuit using a permanent magnet and a magnetic circuit using a DC exciting electromagnet can be formed independently of each other in parallel.
(3) Shorten the circumference of the DC exciting coil and reduce the winding resistance.
(4) Make the area of the air gap between the armature core and the field as wide as possible. (5) The outer cover material should be a non-magnetic material, and an aluminum alloy with good heat dissipation should be used.
(6) To ensure reliability, simplify the structure, and reduce manufacturing costs as much as possible.

The present application is an invention relating to a variable magnetic flux field type radial air gap type synchronous machine having an inner rotor structure.
According to the first invention of the present application, in a radial air gap type synchronous machine having an inner rotor structure, an armature formed by punching and laminating an electromagnetic steel plate and having a centrally wound winding is used as a stator, and the electromagnetic steel plate is punched out. A field formed by embedding a permanent magnet in an SPM shape in a laminated field iron core and using a DC exciting electromagnet together as a rotor is used as a rotor. A space is provided by cutting the part in a cylindrical shape, and a DC excitation winding is provided in the space so as to wind a rotating shaft made of a ferromagnetic material, and the winding is a disk made of a non-magnetic material via an electrical insulator. A shaped support member joins the inner diameter of the armature core, and the two divided fields are fixed to the rotating shaft, respectively. The two bearings that support the rotating shaft and the armor core are made of non-magnetic light metal. Between the group of field cores, permanent magnets, DC exciting electromagnets and rotating shafts that are supported and fixed by the cover and the rotating parts, and the group of DC exciting windings, electrical insulators, support members and cores that are fixed parts. A gap is provided in the field, and the magnetic poles of one of the divided fields are formed by embedding a permanent magnet in an SPM shape with the north pole being a DC exciting electromagnet and the south pole having a space in the outer diameter of the field iron core. The magnetic poles of the other divided field are formed by using a DC excitation electromagnet for the S pole and a space in the outer diameter of the field iron core and embedding a permanent magnet in an SPM shape, and the two fields are mutually formed. Permanent magnets of the same pole and DC exciting electromagnets are arranged next to each other, and by passing a DC current through the DC exciting winding, the DC exciting magnetic flux is generated by a rotating shaft made of a ferromagnetic material ⇒ back yoke of one field ⇒ One DC exciting electric magnet ⇒ one radial air gap ⇒ armature core ⇒ the other radial air gap ⇒ the other DC exciting electric magnet ⇒ the back yoke of the other field ⇒ flowing to the rotating shaft to form a DC exciting electric magnet. On the other hand, the flow of the magnetic flux of the permanent magnet is as follows: N pole of the permanent magnet of the other field → magnetic pole end → radial air gap of the other → armature core → radial air gap of one → magnetic pole end of one field → one S pole of the field permanent magnet → back yoke of one field → rotation axis → back yoke of the other field → permanent magnet of the other field, p permanent magnets on one side and p permanent magnets on one side A radial air gap type variable magnetic flux field type synchronous machine that forms a field having a number of 2p poles is formed by a DC exciting electromagnet.

The second invention of the present application relates to a method of reducing the amount of decrease in the facing area between the field and the armature by fixing the support member of the DC excitation winding to the armature core.
In claim 1, a plurality of protrusions of the electromagnetic steel plate toward the inner diameter side at substantially the center of the inner diameter of the armature core, in a single row or multiple rows in the rotation axis direction, and at several equal positions in the rotation angle direction. A radial air gap type variable magnetic field field synchronous machine is formed by joining a non-magnetic support member that supports the DC exciting winding to the protrusion, positioning in the axial direction, and fixing the support member. To do. As a form of joining the protrusion and the support member, there are a method of sandwiching the support member with the protrusion and a method of surrounding the protrusion with the support member, and the joining method is adhesion, welding, welding, press fitting, crimping, pressure welding, screwing, etc. There are rivet stops and so on.

The third invention of the present application relates to a technique for reducing the cogging torque, which becomes a major obstacle when used as a generator for wind power generation. In claim 1, the number of poles of the field is 2p, and all the teeth of the armature are subjected to concentrated winding to make the number 3 × (2q + 1), and the number of poles of the field and the number of armature teeth. The relationship is 3 × (2q + 1) = 2p ± 1, the number of each phase of the armature winding is (2q + 1), and they are connected to the three phases to form a radial air gap type variable magnetic flux field synchronous machine. It reduces the cogging torque.

The DC exciting magnetic circuit does not use an exciting iron core, and the structure is simplified, the number of air gaps in the exciting circuit is reduced, and the circumference of the DC exciting coil is shortened to reduce the winding resistance. The loss can be reduced. Since a magnetic circuit using a permanent magnet and a magnetic circuit using a DC exciting electromagnet can be formed in parallel in the field magnet, a wide range of choices such as the type and performance of the permanent magnet and the amount used can be taken, and economic design becomes possible. The outer cover material is an aluminum alloy with good heat dissipation, and the internal temperature such as winding temperature and bearing temperature can be lowered, so the size of the equipment can be reduced, and the magnetic attraction and repulsion force by the permanent magnet like the axial air gap type can be reduced. It is possible to provide a highly reliable and low-cost radial air gap type variable magnetic flux field type synchronous machine with less adverse effects.

The cross-sectional view of the whole synchronous machine of this invention is shown. (A) A view of the field A in FIG. 1 is shown. (B) The B arrow view of the field in FIG. 1 is shown. A schematic magnetic circuit of the field magnetic circuit and the entire DC excitation circuit is shown. The whole front sectional view seen from the central part in FIG. 1 is shown. The connection diagram of the whole armature winding is shown.

Embodiments of the present invention will be described with reference to FIGS. 1 to 5, but the present invention is not limited thereto.

The first invention will be described with reference to FIG.
A rotating shaft 42 made of a ferromagnetic material is passed through a bearing 41 at the center of both ends of a bracket 40 made of a non-magnetic material divided into two in the axial direction, and an armature serving as a stator is placed on the inner diameter side of the center of the bracket. 20 is attached, and on the inner diameter side of the armature, the field 10 divided into two in the axial direction is fixed to the rotating shaft by a method such as press fitting or shrink fitting, and the vicinity of the rotating shaft of the facing surfaces of the two fields is A cylindrical space is provided by being scooped out, and a DC exciting coil 30 that winds the rotating shaft is arranged in the central portion near the rotating shaft of the space, and the coil holding portion 31 passes through the exciting coil insulator 32. The coil holding portion is fixed and joined to the inner diameter of the armature core by a circular, thin holding member, whereby the air gap areas G1 and G2 between the armature core 21 and the field 10 are wide in the inner rotor type. The radial air gap type variable magnetic flux field type synchronous machine 1 can be formed.

The field magnet will be described with reference to FIG. Assuming that the polarity of the permanent magnet 13 of one of the two-divided field magnets 10 (FIG. 2 (a)) is N pole, the DC exciting magnet 12 of the other opposite field (FIG. 2 (b)) If the polarity is the same as the north pole, and then the polarity of the DC excitation magnet of one field at a position shifted by 45 ° is the south pole, the polarity of the permanent magnet of the other field is also the south pole, and further. As shown in FIG. 3, the polarity of the permanent magnet of one field at the position shifted by 90 ° is set to N pole, and the polarity of the DC exciting magnet of the opposite field is set to N pole. The polarity of the field-excited magnet is N pole, the polarity of the permanent magnet located between them is S pole, and the magnet of the other field faces a magnet different from the magnet of one field, and the magnet is DC-excited. A permanent magnet is opposed to the permanent magnet, and a DC excitation magnet is opposed to the permanent magnet, and the magnets are arranged so as to have the same polarity to form a field magnetic pole.

The flow of magnetic flux will be described with reference to FIG. The two fields are arranged so that the permanent magnets 13 having the same poles and the DC exciting electromagnets 12 face each other, and by passing a DC current through the DC exciting winding 30, the DC exciting magnetic flux is generated by the rotating shaft 42 made of a ferromagnetic material. ⇒ One field back yoke 11 ⇒ One DC exciting electromagnet 12 ⇒ One radial air gap G1 ⇒ Armor core 21 ⇒ The other radial air gap G2 ⇒ The other DC exciting electromagnet 12 ⇒ The other field back yoke 11 ⇒ Flows to the rotating shaft 42 to form a DC exciting electromagnet, and the flow of magnetic flux of the permanent magnet is the N pole of the permanent magnet 13 of the other field ⇒ magnetic pole end 14 ⇒ radial air gap G2 of the other ⇒ armature iron core 21 ⇒ One radial air gap G1 ⇒ Pole end 14 of one field ⇒ S pole of permanent magnet 13 of one field ⇒ Back yoke 11 of one field ⇒ Rotating shaft 42 ⇒ Back yoke of the other field 11 ⇒ Inner rotor type that flows to the N pole of the permanent magnet 13 of the other field and forms a field with 2p poles by p permanent magnets 13 on one side and p DC exciting electromagnets 12 on one side. A radial air gap type variable magnetic flux field type synchronous machine is formed.

The second invention will be described with reference to FIGS. 1 and 4. The armature core 21 is manufactured by punching an electromagnetic steel plate with an automatic laminated press mold, and has an inner diameter at the center of the rotation axis direction, a single row or a double row in the rotation axis direction, and a number in the rotation angle direction. Protrusions 211 of the electromagnetic steel plate are provided at equal positions toward the inner diameter side, and a circular support member 31 made of a non-magnetic light alloy or synthetic resin that supports the DC excitation winding is joined to the protrusions to form a shaft. It relates to a method of positioning in a direction and fixing a support member to an inner diameter portion of an armature core.
In the first example, protrusions 211 of an electromagnetic steel plate are provided on the inner diameter of the central portion in the rotation axis direction over two rows in the rotation axis direction and at positions equally divided by the number of rotation angle directions toward the inner diameter side, and support members On the outer peripheral portion of the outer diameter of the armature, a relief groove 311 is provided at the same rotation angle as a row of protrusions provided at positions equal to the inner diameter of the armature core, and the support member 31 is attached to the armor core. After fitting into the inner diameter portion and passing through the protrusions 211 in a row on one side, the support member 31 is rotated a little, and the relief groove 311 is positioned between the protrusions 211 and the protrusions 211 as shown in FIG. 4 so as not to shift in the axial direction. This is a method of joining and fixing the support member 31 to the inner diameter portion of the armature core.
In the second example, a protrusion of an electromagnetic steel plate is provided on the inner diameter of the central portion in the rotation axis direction over one row in the rotation axis direction at several equal positions in the rotation angle direction toward the inner diameter side, and a DC excitation winding is provided. The support member is made of three disc-shaped thin plates of aluminum alloy, and the outer diameter of the disc in the middle is made small so that the protrusions of the armature iron core do not touch, and the outer diameter of the discs of the support members on both sides. Is the same as the outer diameter of the first example, a relief groove is provided so that the protrusion can escape, and the support member is fitted into the inner diameter of the armature core as in the first example, and the relief groove of the first disk is a protrusion. This is a method of joining and fixing the armature iron core and the support member composed of three disks in a state where the support member is rotated a little after passing through the above and all the protrusions are surrounded by the disks on both sides. As the joining method, a method such as adhesion, welding, crimping, or pressure welding is adopted. With this technology, it is possible to make an inner rotor type radial air gap type variable magnetic flux field type synchronous machine.

The third invention will be described with reference to FIGS. 4 and 5. In wind power generation, when the wind speed is low, the generator may not start and generate electricity because the cogging torque of the generator is large. Therefore, it is necessary to reduce the cogging torque. Increasing the number of teeth of the armature and the minimum common multiple of the number of poles of the field reduces the cogging torque. Therefore, the number of poles of the field is set to 2p, and all the armature teeth are subjected to the concentrated winding winding 22. The number is 3 × (2q + 1), the relationship between the number of poles in the field and the number of teeth of the armature is 3 × (2q + 1) = 2p ± 1, and the number of each phase of the armature winding is (2q + 1). Connect them in 3 phases. As an example, when p = 4 and q = 1, the armature is as shown in FIG. 4, and the three-phase winding thereof is as shown in FIG. Here, the overline of the alphabet symbol indicates that the winding direction is opposite to that without the overline. With this technology, it is possible to obtain a radial air gap type variable magnetic flux field generator with a small cogging torque.

1 Synchronous machine, electric motor, generator 10 Field 11 Field iron core 12 Exciting magnetic pole 13 Permanent magnet 14 Magnetic pole end 20 Armature 21 Armature core 211 Protrusion 22 Armature winding 221 U-phase winding 222 V-phase winding 223 W Phase winding 30 DC exciting coil 31 Exciting coil support member 311 Relief groove 32 Exciting coil insulator 40 Bracket (non-magnetic light metal, aluminum alloy, etc.)
41 Bearing 42 Rotating shaft (ferromagnetic material)
G1 Air gap between one field and armature G2 Air gap between the other field and armature ⇒ Direction of DC exciting magnetic flux flow → Direction of permanent magnet magnetic flux flow

Claims (3)

In the inner rotor type radial air gap type synchronous machine, the armature formed by punching and laminating electromagnetic steel plates is used as a stator, and the field core formed by punching and laminating electromagnetic steel plates is a permanent magnet. Is embedded in an SPM shape and the field magnet is used as a rotor, and the field is divided into two in the axial direction at the center, and the center of the two opposing field iron cores is hollowed out in a cylindrical shape to create a space. A DC excitation winding is provided in the space so as to wind a rotating shaft made of a ferromagnetic material, and the winding is fixed to a disk-shaped support member made of a non-magnetic material via an electrical insulator. The support member is joined to the inner diameter of the iron core, the two divided fields are fixed to the rotating shaft, and the two bearings that support the rotating shaft and the electric core are made of non-magnetic light metal. Between a group of rotating parts such as field cores, permanent magnets, DC exciting electromagnets and rotating shafts and a group of fixed parts such as DC exciting windings, electrical insulators, support members and element cores. In the magnetic pole of one of the divided fields, the north pole is a DC exciting electromagnet and the south pole is formed by embedding a permanent magnet in an SPM shape with a space in the outer diameter of the field iron core. In the magnetic poles of the other divided field, the S pole is a DC excitation electric magnet, and the N pole is formed by embedding a permanent magnet in an SPM shape with a space in the outer diameter of the field iron core, and two fields. The permanent magnets of the same pole and the DC exciting electromagnet are arranged next to each other, and by passing a DC current through the DC exciting winding, the DC exciting magnetic flux is generated by the rotating shaft made of a ferromagnetic material ⇒ the back of one field. Yoke ⇒ One DC excitation magnet ⇒ One radial air gap ⇒ Armor core ⇒ The other radial air gap ⇒ The other DC excitation magnet ⇒ The back yoke of the other field ⇒ Flows to the rotating shaft to form a DC excitation magnet On the other hand, the flow of the magnetic flux of the permanent magnet is as follows: N pole of the permanent magnet of the other field → magnetic pole end → radial air gap of the other → armature core → radial air gap of one → magnetic pole end of one field → S pole of one field permanent magnet → back yoke of one field → rotation axis → back yoke of the other field → permanent magnet of the other field, p permanent magnets on one side and p on one side Radial air gap type variable magnetic flux field type synchronous machine that forms a field with 2p poles by individual DC exciting electromagnets In claim 1, a protrusion of an electromagnetic steel plate is provided in a single row or multiple rows in the rotation axis direction and at several equal positions in the rotation angle direction toward the inner diameter side at substantially the center of the inner diameter of the armature core. A radial air gap type variable magnetic field field synchronous machine in which a non-magnetic support member that supports a DC excitation winding is joined to the protrusion to fix the axial direction and the rotation direction. In claim 1, the number of poles of the field is 2p, and all the teeth of the armature are subjected to concentrated winding to make the number 3 × (2q + 1), and the number of poles of the field and the number of armature teeth. Relationship 3 × (2q + 1) = 2p ± 1, the number of each phase of the armature winding is (2q + 1), and they are connected to 3 phases. Radial air gap type variable magnetic flux field synchronous machine

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