JP2005176582A - Superconducting motor and automobile employing it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor suitable for driving an electric automobile or a hybrid automobile in which a big driving force can be attained while reducing the size and weight by decreasing the number of turns of the winding of a stator armature and an excellent feature of shunt winding capable of utilizing field weakening and reactance torque is imparted, and to provide an automobile employing that motor. <P>SOLUTION: A polyphase motor comprises a stator, an armature provided in the stator, and a rotor wherein the armature comprises a superconducting coil formed by winding a tape-like superconducting wire spirally and integrally while laying the long side of its cross-section in layers, and the adjacent superconducting coils are arranged such that their positions in the circumferential direction of the stator are partially superposed on each other. An automobile employing the superconducting motor is also provided. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a superconducting motor and an automobile using the superconducting motor. More specifically, a coil made of a superconducting wire (hereinafter referred to as a superconducting coil) is used for an armature (hereinafter referred to as a stator armature) provided in the stator, and is used for an electric vehicle or a hybrid. The present invention relates to a superconducting motor used for driving an automobile and the like, and an automobile using the superconducting motor.

In recent years, electric vehicles and hybrid vehicles that run using an electric motor (hereinafter simply referred to as a motor) as a drive source have attracted attention as environmentally-friendly vehicles.
For example, Japanese Patent Laid-Open No. 2002-166735 discloses a hybrid electric vehicle (hybrid vehicle) that has an internal combustion engine power system, a battery power system, a power converter, and a main transmission, and that has reduced exhaust problems and is excellent in economy. The battery power system receives electric power from the battery and acts as a motor (Claim 1, Claim 2, Paragraph 0016).

  Motors used in electric vehicles and hybrid vehicles are required to have high output, and the motor itself is required to be light and small. Conventional motors for automobiles are mainly synchronous motors, and an armature formed by winding a copper wire in a coil shape is provided on the stator side, and a rotating magnetic field is generated by passing, for example, a three-phase alternating current through the armature. However, in order to reduce the size of such a synchronous motor, it is essential to reduce the size of the stator armature portion.

  However, when using an armature formed by winding a conventional copper wire in a coil shape, it has been difficult to simultaneously achieve high output and miniaturization. Therefore, as a result of intensive studies, the present inventor can use a superconducting coil as a winding of a stator armature, and a large drive even if the number of turns of the coil is reduced by passing a large current through the superconducting coil. It has been found that since the force can be obtained, the size and weight of the stator armature portion can be significantly reduced while maintaining a high output, and thus the motor can be reduced in size and weight. As such a superconducting coil, a coil in which a tape-like superconducting wire is laminated so that the long sides of its cross section overlap each other as shown in FIG. 3 and FIG. Found to be used.

  On the other hand, as a method of winding an armature coil of a conventional synchronous motor, concentrated winding in which one coil is wound for each tooth, or one coil is wound over a plurality of teeth, and the position of each coil in the circumferential direction is determined. There are distributed windings that overlap. Distributed winding has excellent characteristics such as improved voltage waveform, easy suppression of back electromotive force, field weakening control, and effective use of reactance torque. High torque and particularly wide operating range are required. The present invention is preferably applied to a motor for driving automobiles.

  However, the tape-like superconducting wire as described above cannot be distributedly wound by the same method as that of the conventional coil. Therefore, development of a coil arrangement method that uses a coil-like superconducting wire laminated in a spiral shape so that the long sides of its cross-section overlap and is integrated, and has the same excellent features as distributed winding Is desired.

JP 2002-166735 A (Claim 1, Claim 2, Paragraph 0016)

  The present invention has a distribution in which the number of windings of the stator armature is reduced to achieve a reduction in size and weight, and a large driving force can be obtained, and field weakening control and reactance torque can be effectively used. It is an object of the present invention to provide a motor that has excellent winding characteristics and is suitable for driving an electric vehicle or a hybrid vehicle, and a vehicle that uses the motor.

  The present inventor is a multiphase motor having an armature provided on a stator, and the stator armature is formed by laminating a tape-like superconducting wire so that the long sides of the cross-section are stacked and spirally wound. A plurality of superconducting coils formed in the same manner are used so that adjacent superconducting coils (which are closest to the position in the stator circumferential direction and which have different phases of alternating current flow) partially overlap each other in the circumferential direction of the stator. As a result of the arrangement, it has been found that high output and miniaturization of the motor can be achieved at the same time and that excellent characteristics of distributed winding can be obtained, and the present invention has been completed.

  The present invention provides a multiphase motor having a stator, an armature provided on the stator, and a rotor according to claim 1, wherein the armature has a tape-like superconducting wire whose longitudinal sides overlap each other. It is characterized by comprising superconducting coils that are integrally formed by winding spirally while being stacked on each other, and adjacent superconducting coils are arranged so that their circumferential positions partially overlap each other. A superconducting motor is provided.

  In the superconducting motor of the present invention, a rotating magnetic field is generated by flowing alternating currents out of phase to the plurality of armatures provided in the stator, and the driving force is generated by the attractive force and repulsive force with the rotor. Occurs. As the alternating current, a multi-phase alternating current such as a three-phase alternating current is used to generate a smooth rotating magnetic field.

  The superconducting coil can pass a much larger current than a coil made of a normal copper wire or the like, and can generate a large magnetic flux density even when the number of turns of the coil is small. Therefore, the number of turns can be reduced, and the armature and thus the motor can be reduced in size and weight, and a high output can be achieved.

  The superconducting coil used in the superconducting motor of the present invention is formed by laminating a tape-shaped superconducting wire so as to overlap the long sides of the cross-sections of adjacent tapes, and winding them in a spiral shape. This superconducting coil usually has a racetrack shape as shown in FIG. 3 or a pancake shape as shown in FIG. In each coil, a single tape-shaped superconducting wire is wound in a spiral shape, and laminated so that the upper and lower surfaces of the tapes of adjacent spiral periods (coil periods) overlap. Adjacent spiral tapes are insulated by an insulating material or the like, and an insulating adhesive is exemplified as the insulating material.

  The superconducting motor of the present invention also has a feature in a mode in which an armature is provided on a stator, and adjacent superconducting coils are arranged such that their positions in the stator circumferential direction partially overlap each other. Adjacent superconducting coils carry alternating currents that are out of phase, but by arranging these coils in this way, the voltage waveform is improved, the generation of counter electromotive force is easily suppressed, weak magnetic field, reactance torque An excellent feature of distributed winding, such as being able to be utilized, is achieved.

  The positions in the circumferential direction of the stator are arranged so as to partially overlap each other in the sectional view of the motor cut perpendicularly to the motor rotation axis, the rotor rotation axis A, the left end (inner circumference side) point B of the superconducting coil, When the triangle formed by the right end (inner peripheral side) point C of the superconducting coil is a triangle ABC (ABC in FIGS. 1 and 2), the triangles ABC of adjacent superconducting coils partially overlap each other. Say to be placed. Since parts overlap, there must also be parts that do not overlap. In order to achieve smooth rotation, it is preferable for all superconducting coils in the motor to have the same area ratio of overlapping portions of the triangle ABC (area ratio of overlapping portions to the entire area of the triangle ABC).

  When the number of armatures (the number of poles) is large, depending on the size of the superconducting coil in the stator circumferential direction of the coil, the positions of the adjacent coils of the adjacent coils and the like in the stator circumferential direction are the same. You may arrange | position so that a part may overlap.

Examples of a method for arranging the superconducting coils so that the positions in the circumferential direction of the stator partially overlap each other include the following arrangement method 1 and arrangement method 2.
Arrangement method 1: A superconducting coil whose positions in the circumferential direction partially overlap each other is arranged on a circumference having different radii around the rotor rotation axis.
Arrangement method 2: The superconducting coil is arranged at an angle with respect to the circumferential direction of the stator.
It is also possible to combine the placement method 1 and the placement method 2.

  Claim 2 of the present invention corresponds to an aspect adopting the arrangement method 1, and is the superconducting motor described above, wherein each of the superconducting coils arranged so that the positions in the circumferential direction of the stator partially overlap each other, The present invention provides a superconducting motor characterized in that it is arranged on the circumferences having different radii around the rotor rotation axis.

  Adjacent coils through which alternating phases of different phases are passed are arranged so that their positions in the circumferential direction of the stator partially overlap each other. In this embodiment, they are arranged on the circumferences having different radii. On the other hand, coils whose positions in the coil circumferential direction do not overlap such as coils that are not adjacent to each other may be arranged on the same circumference.

  In particular, it is preferable that the superconducting coils (the positions in the circumferential direction of the stator do not overlap with each other) through which alternating currents of the same phase flow are arranged on the same circumference in order to generate a smooth rotating magnetic field. The third aspect of the present invention is the superconducting coil according to the second aspect, wherein coils having the same phase alternating current (coils corresponding to the same phase) are arranged on the same circumference around the rotor rotation axis. The present invention provides a superconducting motor that is characterized by the above. FIG. 1 shows an example of this arrangement. Normally, superconducting coils corresponding to the same phase are arranged on the same circumference, and the circumference radius of each phase is made different. In the case of an N-phase motor, the superconducting coils are arranged in N stages. It becomes a stator armature.

  A fourth aspect of the present invention corresponds to an aspect adopting the arrangement method 2, and is the above-described superconducting motor, wherein the superconducting coil is arranged at an angle with respect to the stator circumferential direction. A superconducting motor is provided. FIG. 2 shows an example of this arrangement. By arranging in this way, adjacent coils whose positions in the circumferential direction of the stator partially overlap each other can be arranged on the same circumference. .

  The superconducting motor of the present invention is preferably applied to induction motors, synchronous motors, and the like. A fifth aspect of the present invention corresponds to this preferred embodiment, and provides a superconducting motor, which is the superconducting motor, which is an induction motor or a synchronous motor.

  The tape-shaped superconducting wire used in the superconducting motor of the present invention is not particularly limited, but is usually produced by the following method. First, a metal tube filled with a raw powder mixture of a superconducting wire is drawn to obtain a clad wire coated with the material of the metal tube using the raw powder mixture as a core material. A plurality of clad wires obtained in this way are bundled, inserted into a metal tube again, and drawn, whereby the raw material powder mixture becomes a filament, and many filaments are embedded in the metal tube material (metal sheath). A core wire is obtained. The multifilamentary wire thus obtained is mechanically pressurized from above and below to form a tape (rolling process) to obtain a superconducting wire. As the material of the metal tube, silver or a silver alloy is preferably used.

  As the superconducting wire, a bismuth-based or rare earth-based superconducting wire is preferably exemplified. Claim 6 corresponds to this preferred embodiment, and provides a superconducting motor, characterized in that a bismuth-based or rare earth-based superconducting wire is used as the superconducting wire.

  A preferred example of the bismuth-based superconducting wire is a Bi-2223 wire having a main phase of Bi-2223 phase with a composition ratio (molar ratio) of (Bi + Pb): Sr: Ca: Cu of about 2: 2: 2: 3. Is done. Bi-2223 wire has a high critical temperature of about 110K, and when the critical current value is not coiled, it reaches 100 times at 77K and 200-300 times at 20K compared to copper wire. Even in this case, a very large critical current value of about half of the above can be obtained.

  The rare earth-based superconducting wire is a high-temperature superconducting wire composed of Re (rare earth) -Ba-Cu-O, and the rare earth is exemplified by holmium. The rare earth-based superconducting wire can achieve a higher current density than the bismuth-based superconducting wire, and also has the characteristics of good magnetic field resistance.

  As described above, by using the superconducting wire, it is possible to significantly increase the current to be energized as compared with the case of the copper wire. However, since the magnetic flux density saturates at a certain ampere turn, it is often more effective to reduce the number of turns by increasing the current while maintaining the ampere turn, rather than measuring an increase in ampere turn (for example, If a bismuth-based superconducting wire can pass a current 100 times that of a copper wire, the number of turns can be reduced to 1/100. By reducing the number of turns, the armature can be downsized, and thus the motor can be downsized.

  The superconducting motor of the present invention is preferably used for automobiles. Accordingly, the present invention provides an automobile characterized in that, in claim 7, the superconducting motor is used. In particular, the superconducting motor of the present invention is preferably used for driving electric vehicles and hybrid vehicles.

  The superconducting motor of the present invention exhibits a large driving force upon receiving electric energy, but also functions as a generator that generates electric energy by receiving mechanical (rotational) energy. For example, when the superconducting motor of the present invention is used for driving an electric vehicle or a hybrid vehicle, it functions as a generator and generates a regenerative current when the vehicle is decelerated, stopped, or traveling downhill. The battery can be charged.

  The superconducting motor of the present invention has a weakening magnetic field that reduces the number of windings of the stator armature and achieves a reduction in size and weight, while providing a large driving force and easily suppressing the occurrence of back electromotive force. It also has an excellent feature of distributed winding such that the reactance torque can be utilized, and is suitably used for driving an electric vehicle or a hybrid vehicle. In addition, in an automobile using the superconducting motor, it is easy to achieve weight reduction and high output by utilizing the above-described features.

  FIG. 1 is a cross-sectional view of an example of the superconducting motor of the present invention perpendicular to the rotor rotation axis. The superconducting motor of this example is a three-phase, eight-pole type, and superconducting coils 1, 2, and 3 corresponding to each phase are arranged along the inner circumference of the stator 5, totaling 24 for each phase. As the superconducting motor of the present invention, the number of poles is not limited to 8, and motors of other poles such as 4 poles, 6 poles, 12 poles and the like can also be the superconducting motors of the present invention. Note that superconducting coils 1 ′, 2 ′, and 3 ′ in FIG. 1 are coils corresponding to the same phase as superconducting coils 1, 2, and 3, respectively, but have opposite polarities. In the drawing, the outline of the coil having the opposite polarity is indicated by a dotted line.

  The superconducting coils 1, 2 and 3 and the superconducting coils 1 ', 2' and 3 'have a racetrack shape shown in FIG. 3 or a pancake shape shown in FIG. The outline of each coil in FIGS. 1 and 2 corresponds to the shape when the coil is viewed from the direction of the arrow in FIG. 3 or FIG. 3 and 4 will be described in detail later.

  As is clear from FIG. 1, for adjacent coils, for example, in the coils 1 and 2, the coils 2 and 3, the rotor rotation axis A, the left end (inner peripheral side) point B of the superconducting coil, the right end of the superconducting coil ( The triangle ABC formed by the inner circumference side point C partially overlaps each other. In this example, the triangle ABC also partially overlaps the adjacent coils of the adjacent coils.

The superconducting coils 1, 2 and 3 and the superconducting coils 1 ', 2' and 3 'are sequentially supplied with U, V and W phases of three-phase alternating current, and a rotating magnetic field is generated. At the center of the superconducting motor, a rotor 4 is provided so as to be rotatable about a rotation axis. The motor of this example is a synchronous motor, and a permanent magnet (not shown) is provided along the outer periphery of the rotor 4 on the outer peripheral side of the rotor 4. A driving force is generated by the attractive and repulsive force between the rotating magnetic field generated by the superconducting coil and the permanent magnet of the rotor 4.
Instead of the permanent magnet, an electromagnet can be used, or a superconducting coil can be used, and these cases also function as a synchronous motor.

  In order to keep the superconducting coils 1, 2 and 3 and the superconducting coils 1 ′, 2 ′ and 3 ′ in a superconducting state, it is necessary to cool the coils using a refrigerant and / or a cooler. (As described above, when a superconducting coil is used instead of the permanent magnet of the rotor, it is necessary to cool the coil so as to keep the superconducting state.) Therefore, in the motor of this example, a refrigerant circulation jacket (not shown) is used. Is provided on the outer periphery of the motor.

  As the refrigerant, liquid hydrogen, liquid nitrogen, or the like is used. In automobiles using fuel cells, liquid hydrogen has the advantage that it can serve both as a refrigerant and power generation, but liquid nitrogen is usually preferred because it is cheap and safe. If the bismuth-based superconducting wire is used, the superconducting state can be maintained by cooling with liquid nitrogen.

  FIG. 2 is a cross-sectional view perpendicular to the rotor rotation axis of another example of the superconducting motor of the present invention. The superconducting motor of this example is also a three-phase eight-pole type, and superconducting coils 1a, 2a, and 3a corresponding to each phase are arranged along the inner circumference of the stator 5 in total, eight for each phase. .

  Superconducting coils 1'a, 2'a and 3'a in FIG. 2 are coils corresponding to the same phase as superconducting coils 1a, 2a and 3a, respectively, but have opposite polarities. In the drawing, the outline of the coil having the opposite polarity is indicated by a dotted line.

  Also in this example, for the adjacent coils, for example, in the coils 1a and 2a, the coils 2a and 3a, the rotor rotation axis A, the left end (inner peripheral side) point B of the superconducting coil, and the right end (inner peripheral side) of the superconducting coil. Triangles ABC formed by the points C partially overlap each other. However, each superconducting coil (superconducting coils 1'a, 2'a and 3'a, superconducting coils 1a, 2a and 3a) is arranged at an angle of 15 degrees with respect to the circumferential direction of the stator. Can be arranged on the same circumference. The other points such as the mechanism for generating the driving force and cooling are the same as in the example of FIG.

  FIG. 3 is a perspective view showing a racetrack-shaped superconducting coil. The superconducting coil of this shape is formed by laminating tape-shaped superconducting wires in a spiral shape so that the upper and lower surfaces of the tapes of adjacent spiral periods (coil periods) overlap, resulting in a racetrack shape as shown in FIG. It is formed by wrapping around.

  FIG. 5 is a schematic cross-sectional view of a superconducting coil showing a state in which superconducting wires are laminated so that the upper surface and the lower surface of a tape having a helical period (coil period) overlap. As shown in FIG. 5, the superconducting coil is formed by laminating superconducting wires 6 in which superconductor filaments 7 are embedded in silver or a silver alloy. An insulating layer 8 made of an insulating adhesive is provided between the superconducting wires 6.

  FIG. 6 is a partial enlarged cross-sectional view of the superconducting coil of FIG. 5, and shows an enlarged view of the M part of FIG. FIG. 6 shows that a superconductor filament 7 is embedded in silver or a silver alloy 9 to form a superconducting wire 6, and an insulating layer 8 is provided between the superconducting wires 6. Has been.

  It is also possible to use a pancake-shaped superconducting coil shown in FIG. 4 instead of the racetrack-shaped superconducting coil. The pancake-shaped superconducting coil is also different from the racetrack-shaped superconducting coil only in the external shape, and has the same laminated structure and internal configuration.

  The automobile of the present invention is equipped with the superconducting motor formed as described above. In particular, electric vehicles and hybrid vehicles in which the superconducting motor is mounted for driving are typical examples.

  An electric vehicle or a hybrid vehicle equipped with a synchronous motor (superconducting motor) of the above form for driving has a battery such as a fuel cell or a secondary battery, an inverter, and a direct current from the battery. It is changed to alternating current by an inverter (voltage is raised by a booster if necessary) and supplied to a superconducting motor to generate a driving force of an automobile. The automobile of the present invention further includes cooling means such as a cooling device and a refrigerant circulation device for maintaining the superconducting state of the superconducting coil, and further booster means for increasing the voltage supplied to the superconducting motor as necessary, the superconducting You may have a pressure | voltage fall means for reducing the voltage which generate | occur | produced with the motor.

  In the case of a hybrid vehicle, the driving force of the vehicle is generated by combining the superconducting motor and the internal combustion engine. The superconducting motor of the present invention can be used in any type of hybrid vehicle such as a parallel type, a series type, and a parallel series type.

  The superconducting motor for driving installed in the automobile of the present invention can also function as a generator that generates electricity by receiving mechanical energy when the automobile is decelerated or traveling downhill. The generated electricity is converted into a direct current by an inverter or the like, and then supplied to a battery (secondary battery) through a step-down unit as necessary to charge the battery.

It is sectional drawing perpendicular | vertical to a rotating shaft of an example of the superconducting motor of this invention. It is sectional drawing perpendicular | vertical to a rotating shaft of another example of the superconducting motor of this invention. It is a perspective view of an example of the superconducting coil used for the superconducting motor of the present invention. It is a perspective view of another example of the superconducting coil used for the superconducting motor of the present invention. It is a schematic sectional drawing of an example of the superconducting coil used for the superconducting motor of this invention. It is a partial expanded sectional view of FIG.

Explanation of symbols

1, 2, 3, 1 ', 2', 3 ', 1a, 2a, 3a, 1'a, 2'a, 3'a, superconducting coils 4, 4a, rotors 5, 5a, stator 6, superconducting wire 7 , Superconductor filament 8, Insulating layer 9, Silver alloy A, Rotor rotating shaft

Claims (7)

  A multiphase motor having a stator, an armature provided on the stator, and a rotor, wherein the armature is formed by spirally winding a tape-like superconducting wire while laminating the long sides of its cross section. A superconducting motor comprising a formed superconducting coil and having adjacent superconducting coils arranged so that their circumferential positions partially overlap each other.   2. The superconducting coils arranged so that the positions in the circumferential direction of the stator partially overlap each other are arranged on circumferences having different radii around the rotor rotation axis. Superconducting motor.   The superconducting motor according to claim 2, wherein the superconducting coils through which alternating currents having the same phase flow are arranged on the same circumference around the rotor rotation axis.   The superconducting motor according to any one of claims 1 to 3, wherein the superconducting coil is disposed at an angle with respect to the circumferential direction of the stator.   The superconducting motor according to any one of claims 1 to 4, wherein the superconducting motor is an induction motor or a synchronous motor.   6. The superconducting motor according to claim 1, wherein a bismuth or rare earth superconducting wire is used as the superconducting wire. An automobile using the superconducting motor according to any one of claims 1 to 6.

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