JP2017017783A - Variable magnetic flux type rotating electrical machine - Google Patents

Abstract

Provided is a technique capable of improving the efficiency while ensuring the output of a rotating electrical machine. A bypass path serving as a path for a magnetic flux emitted from a permanent magnet constituting one magnetic pole to leak to a magnetic pole side constituted by another adjacent permanent magnet, and a q-axis magnet electrically orthogonal to a d-axis magnetic path. A first magnetic barrier provided between the bypass path and the air gap, and a q-axis magnetic path electrically orthogonal to the d-axis magnetic path, the rotor being more than the bypass path A second magnetic barrier provided on the rotation center side of the first magnetic barrier and a bridge-shaped portion disposed between the first magnetic barrier and the air gap so as to be connected to the magnetic flux inflow portion and the magnetic flux outflow portion. A rotor is provided. The thickness of the permanent magnet of the rotor in the d-axis magnetic path direction is equal to or greater than the embedding depth from the outer peripheral surface of the rotor to the outer peripheral surface of the deepest permanent magnet. [Selection] Figure 1

Description

  The present invention relates to a variable magnetic flux type rotating electrical machine.

  Conventionally, in a rotor of an embedded magnet type synchronous motor, when there is no load, a rotation having a leakage magnetic flux path formed so that leakage magnetic flux from a permanent magnet flows in a direction opposite to the main magnetic flux and circulates in the rotor. A child structure is known (see Patent Document 1). This embedded magnet type synchronous motor has the leakage magnetic flux path, thereby reducing the amount of magnetic flux of the main magnetic flux component when there is no load. Thereby, the iron loss of the stator caused by the influence of the main magnetic flux component is reduced, so that the efficiency of the electric motor is improved.

JP 2010-273416 A

  However, since the amount of magnetic flux of the main magnetic flux component is reduced by providing the leakage magnetic flux path for the purpose of improving the efficiency of the electric motor, there is a problem that the output is lowered.

  An object of this invention is to provide the technique which can improve efficiency (power factor), ensuring the output of the rotary electric machine which has a function as an electric motor.

  A variable magnetic flux type rotating electrical machine according to the present invention is substantially symmetric with respect to a stator having a stator winding for generating a rotating magnetic field, a plurality of permanent magnets forming a d-axis magnetic path, and a magnetic pole center of the permanent magnet. And a rotor that forms an air gap with the stator. The rotor includes a bypass path serving as a path through which a magnetic flux emitted from a permanent magnet constituting one magnetic pole leaks to a magnetic pole side constituted by another adjacent permanent magnet, and q orthogonal to a d-axis magnetic path. A first magnetic barrier provided between the bypass path and the air gap, a q-axis magnetic path electrically orthogonal to the d-axis magnetic path, and more than the bypass path. A second magnetic barrier provided on the rotation center side of the rotor, and a bridge-shaped portion disposed between the first magnetic barrier and the air gap and connected to the magnetic flux inflow portion and the magnetic flux outflow portion; Have The thickness of the permanent magnet in the d-axis magnetic path direction is equal to or greater than the embedding depth from the outer peripheral surface of the rotor to the rotor outer peripheral surface of the deepest permanent magnet.

  According to the present invention, in addition to having a magnetic circuit shape capable of controlling the leakage magnetic flux by the winding current, the permanent-magnet embedding depth is set shallow so that the inductance Ld in the d-axis direction and the q-axis direction are set. In addition, the inductance Lq in the d-axis direction is further reduced by increasing the thickness of the permanent magnet. Thereby, a power factor can be improved, ensuring the output of an electric motor.

FIG. 1 is a configuration diagram of the variable magnetic flux rotating electric machine according to the first embodiment viewed from a plane perpendicular to the axial direction. FIG. 2 is a diagram for explaining the outline of the operation of the variable magnetic flux leakage motor. FIG. 3 is an enlarged view of FIG. 1 around the d-axis shown in FIG. FIG. 4 is a characteristic diagram showing the relationship between the current flowing through the stator winding and the torque in the variable magnetic flux rotating electric machine according to the first embodiment. FIG. 5 is a characteristic diagram showing the relationship between the current flowing through the stator winding and the torque constant in the variable magnetic flux rotating electric machine according to the first embodiment. FIG. 6 is a vector plan view of the dq coordinate system showing the characteristics of the rotating electrical machine. FIG. 7 is a diagram showing the relationship between the number of turns of the stator winding and the d-axis linkage magnetic flux. FIG. 8 is a configuration diagram of the variable magnetic flux rotating electric machine according to the first embodiment viewed from a plane perpendicular to the axial direction. FIG. 9 is a configuration diagram of the variable magnetic flux rotating electric machine according to the second embodiment viewed from a plane perpendicular to the axial direction. FIG. 10 is a configuration diagram of the variable magnetic flux rotating electric machine according to the second embodiment viewed from a plane perpendicular to the axial direction.

[First embodiment]
FIG. 1 is a configuration diagram viewed from a cross section perpendicular to the axial direction of the variable magnetic flux rotating electric machine 100 of the first embodiment, and shows a quarter of the entire configuration. The remaining three-fourth part of the entire configuration is continuously repeated as shown in FIG. The variable magnetic flux type rotating electrical machine according to the present embodiment is a rotating stator 1 having an annular shape, a concentric shape with the stator 1, and an air gap 13 disposed between the stator 1 and the stator 1. An electric motor or a generator is configured by including a child 2 and a plurality of permanent magnets 3 fitted to the rotor 2.

  The stator 1 includes a ring-shaped stator core 11, a plurality of teeth 8 projecting from the stator core 11 toward the inner peripheral side, and a slot 9 that is a space between adjacent teeth 8. A stator winding 10 is wound around the teeth 8. The stator core 11 is formed of, for example, an electromagnetic steel plate that is a soft magnetic material.

  The rotor 2 has a rotor core 12. The rotor core 12 is formed in a cylindrical shape by a so-called laminated steel plate structure in which a large number of electromagnetic steel plates formed by punching a metal plate having a high magnetic permeability into an annular shape are laminated in the axial direction. ing. Further, in the vicinity of the peripheral portion of the rotor core 12 facing the stator 1, a plurality of permanent magnets 3 are equidistant from each other along the circumferential direction, and the polarities of the adjacent permanent magnets are different from each other. It is provided to become. Note that the rotor core 12 according to the variable magnetic flux rotating electric machine of the present embodiment has an 8-pole structure in which eight permanent magnets are provided along the circumferential direction, as inferred from the partial configuration shown in FIG. .

  Further, the rotor 2 has magnetic barriers 4 and 5 which are space portions formed by punching an electromagnetic steel plate forming the rotor core 12 between the magnetic poles formed by the adjacent permanent magnets 3. . The magnetic barriers 4 and 5 have a larger magnetic resistance than the magnetic steel sheet. Therefore, the magnetic barriers 4 and 5 act as a magnetic flux barrier against the magnet magnetic flux in the magnetic circuit formed by the permanent magnet 3 on the rotor 2. As shown in the figure, the magnetic barrier 4 is formed in a substantially triangular shape having a narrower width on the rotation center side than on the outer periphery side of the rotor 2. The magnetic barrier 5 is formed in a substantially U shape so as to cover the magnetic barrier 4 closer to the center of rotation than the magnetic barrier 4. However, the shape of the magnetic barriers 4 and 5 is not limited to the shape shown in the drawing as long as the technical effects described later are produced. Further, the magnetic barriers 4 and 5 are formed in the rotor 2 as shown in the figure, so that the magnetic flux emitted from the permanent magnet 3 constituting one magnetic pole is constituted by another adjacent permanent magnet 3. A magnetic flux bypass path 6 is formed as a path for leakage to the magnetic pole side. Further, the rotor 2 is provided with a narrow bridge-shaped portion 7 connected to the magnetic flux bypass path 6 on the outer peripheral side of the magnetic barrier 4.

  The permanent magnet 3 is fixed to the rotor core 12 by being fitted into a gap formed in a corresponding portion of the rotor core 12. In the permanent magnet 3, the radial direction of the rotor 2 is the magnetization direction. Here, in the present embodiment, the geometric center of the permanent magnet 3 is defined as a d-axis, and a position electrically orthogonal to the d-axis is defined as a q-axis. In addition, since the variable magnetic flux type rotating electrical machine of the present embodiment has an 8-pole structure, a position 22.5 degrees in mechanical angle from the d axis is defined as the q axis. The magnetic barriers 4 and 5 described above are formed on the q axis.

  The above is the basic configuration of the variable magnetic flux rotating electric machine according to the first embodiment. Here, before the detailed description of the present embodiment, the basic principle of the variable magnetic flux rotating electric machine that is the subject of the present invention will be described.

  The variable magnetic flux type rotating electrical machine targeted by the present invention is a magnetic path of a part of magnetic flux (leakage magnetic flux) emitted from a permanent magnet provided in a rotor by the action of a load current (stator current) applied to a stator winding. It can be changed. With this feature, the rotating electrical machine can passively change the stator flux linkage by controlling the stator current, so that the magnetic force of the permanent magnet included in the rotor can be made apparently variable by current control. It has the characteristics that can Due to such characteristics, the variable magnetic flux rotating electrical machine that is the subject of the present invention is also called a variable leakage magnetic flux motor.

  FIG. 2 is a configuration diagram showing a part of the variable magnetic flux leakage motor, and is a diagram for explaining the outline of the operation of the variable magnetic flux leakage motor. However, since the shape and arrangement of each component included in the variable magnetic flux leakage motor shown in FIG. 2 are the general ones shown for explaining the outline of the operation, the detailed part excluding the basic configuration is the same as that of the present invention. Different.

  The variable magnetic flux leakage motor shown in FIG. 2 includes a stator 101 and a rotor 102 arranged with an air gap formed between the stator 101 and the stator 101. The rotor 102 includes a permanent magnet 103, magnetic barriers 104 and 105 (also referred to as flux barriers), and a magnetic barrier 104 from a magnetic pole side formed by the permanent magnet 103 to a magnetic pole side formed by an adjacent permanent magnet 103. , 105 and a magnetic flux bypass path 106 connected via each other. Note that the direction indicated by the arrow on the left side of the figure indicates the direction of rotation of the rotor 102.

  A magnetic path direction 15 shown in FIG. 2 indicates a direction in which leakage magnetic flux flows when no current is passed through the stator windings of the stator 101. As shown in FIG. 2, a part of the magnetic flux emitted from the permanent magnet 103 leaks to the adjacent different pole side through the magnetic flux bypass 106 in the rotor.

  For this reason, since the magnetic flux amount of the main magnetic flux component from the permanent magnet 103 toward the stator 101, that is, the stator linkage magnetic flux is relatively reduced, the magnetic force of the permanent magnet 103 is apparently weakened. Thereby, the iron loss which generate | occur | produces with a stator linkage magnetic flux can be reduced. This effect is particularly effective in improving the efficiency of the rotating electrical machine in a low load and high speed region.

  On the other hand, the magnetic path direction 20 indicates the direction in which the magnetic flux flows when a current is passed through the stator winding. When the stator current flows, the magnetic flux emitted from the permanent magnet 103 is attracted toward the stator side in the rotation direction of the rotor 102 as indicated by the magnetic path direction 20. For this reason, when no current is supplied to the stator winding, the magnetic flux leaking in the rotor 102 as a leakage magnetic flux can be efficiently converted into the stator linkage magnetic flux. Thereby, the rotating electrical machine can output a high torque equivalent to a state in which the magnetic flux emitted from the permanent magnet 103 is not leaking.

  As described above, by providing a magnetic flux bypass path between the magnetic poles configured in the rotor and changing the leakage flux in the rotor by controlling the stator current, the stator linkage flux has a characteristic of passively changing. The rotating electrical machine is referred to as a variable magnetic flux rotating electrical machine (variable leakage flux motor).

  The above is the basic principle of the variable magnetic flux type rotating electrical machine that is the subject of the present invention. Hereinafter, the details of the shape and arrangement of each component included in the variable magnetic flux rotating electric machine 100 according to the first embodiment of the present invention will be described with reference to the drawings.

  FIG. 3 is a configuration diagram viewed from a cross section perpendicular to the axial direction of the variable magnetic flux rotating electrical machine 100 of the first embodiment, and is an enlarged view of FIG. 1 centering on the d axis shown in FIG. . With reference to FIG. 3, a configuration that is a premise of the characteristics of the variable magnetic flux rotating electric machine of the present embodiment will be described.

  As described above, the magnetic flux bypass path 6 is a path when the magnetic flux emitted from the permanent magnet 3 constituting one magnetic pole leaks to the magnetic pole side constituted by the other adjacent permanent magnet 3. A magnetic flux inflow portion and a magnetic flux outflow portion (hereinafter referred to as magnetic flux inflow / outflow portion 14) of the magnetic flux bypass path 6 have a width represented by C in the figure and are arranged in the vicinity of the air gap 13. In addition, a narrow magnetic path 16 having a width A is formed in the rotor core 12 between the permanent magnet 3 and the magnetic barrier 5. The width A of the magnetic path 16 is set smaller than the width C of the magnetic flux inflow / outflow portion 14 of the magnetic flux bypass path 6. That is, on the rotor core 12, the permanent magnet 3 and the magnetic barrier 5 are such that the width C of the magnetic flux inflow / outflow portion 14 of the magnetic flux bypass path 3 and the width A of the magnetic path 16 have a relationship of A <C. It is arranged relative to.

  By having the relationship of “A <C”, the magnetic flux bypassing the magnetic flux from the permanent magnet 3 leaks to the different polarity side of the permanent magnet 3 via the magnetic path 16 rather than the magnetic resistance. The magnetic resistance when leaking to the different pole side of another adjacent permanent magnet 3 via the path 6 is smaller. For this reason, most of the leakage magnetic flux out of the magnetic flux emitted from the permanent magnet 3 passes through the magnetic flux bypass path 6.

  Further, as described above, the magnetic flux inflow / outflow portion 14 of the magnetic flux bypass path 6 is disposed in the vicinity of the air gap 13. Thereby, it is easy to control the magnetic flux flowing through the magnetic flux bypass path 6 by controlling the current supplied to the stator winding.

  In addition, the variable magnetic flux type rotating electrical machine according to the present embodiment has a leakage magnetic flux that flows through the magnetic flux bypass path 6 when the current I applied to the stator winding is small as in no load or low load. Therefore, the counter electromotive force generated by the magnet magnetic flux from the permanent magnet 3 is reduced, and the torque Tr generated in the rotor 2 is reduced. On the other hand, when the current I energized to the stator winding is increased in order to rotate the rotating electrical machine at high speed, the leakage magnetic flux is reduced and the main magnetic flux component linked to the stator side is relatively increased. Can be high. In other words, the current I and the torque Tr of the variable magnetic flux rotating electrical machine according to the present embodiment increase in the rate of change of the torque Tr as the current I increases as shown by the dotted line in FIG.

  In other words, in the variable magnetic flux rotating electrical machine according to the present embodiment, when the torque Tr is expressed by Tr = KT × I by the torque constant KT and the current I, the torque constant KT is a function KT of the current I = Kt (I), which has a relationship of “d (Kt (I)) / dI ≧ 0” in a region below the magnetic saturation point of the core material of the stator core 11.

  Therefore, when a current is applied to the stator 1, the amount of linkage between the magnetic flux and the stator winding (stator linkage flux) increases, and the torque constant increases. For this reason, in the low torque range, the stator linkage magnetic flux decreases, so that the iron loss is reduced and the induced voltage is also reduced, so that the variable speed range is expanded. Since the magnetic circuit in the rotor 2 is formed substantially symmetrically with respect to the magnetic pole center of the permanent magnet 3, substantially the same characteristics can be obtained regardless of the rotation direction of the rotor 2.

  Furthermore, the relationship “d (Kt (I)) / dI ≧ 0” described above indicates that the amount of leakage of the magnet magnetic flux in the no-load state in the magnet magnetic flux distribution in the rotor 2 is different from that of the stator 1. It shows that the maximum torque constant KT_max is set to be larger than the minimum torque constant KT_min by 10% or more with respect to the minimum torque constant KT_min. That is, as shown by the dotted line in FIG. 5, when no current is passed through the stator winding 10, the torque constant KT is set to the minimum value KT_min. Set to KT_max. The maximum torque constant KT_max is set larger by 10% or more than the minimum torque constant KT_min. By setting in this way, magnet magnetic flux can be controlled by normal current control with respect to the stator 1 without using an additional structure or a special control method.

  Furthermore, due to the arrangement of the magnetic barriers 4 and 5 and the permanent magnet 3 on the rotor core 12, the d-axis magnetic resistance is set smaller than the q-axis magnetic resistance. That is, the rotor 2 in the present embodiment has a forward salient pole characteristic in which the d-axis direction inductance Ld and the q-axis direction inductance Lq have a relationship of Ld> Lq.

  The variable magnetic flux type rotating electrical machine according to the present invention is a product of the power factor (the ratio of the effective power to the apparent power) and the output (the product of the rotational speed and the torque) with respect to the variable magnetic flux type rotating electrical machine having the configuration and characteristics as described above. ) Was made with various devices for the purpose of improvement.

  Here, in order to improve the power factor, it is necessary to reduce the power factor angle θ in FIG. FIG. 6 is a vector diagram of the dq coordinate system showing the characteristics of the rotating electrical machine, where I is the current vector, V is the armature voltage vector, Ψa is the magnetic flux of the permanent magnet 3, and λ is the armature linkage. It represents a magnetic flux vector (stator interlinkage magnetic flux vector). The power factor angle θ [rad] is a lagging phase angle of the current vector I with respect to the armature voltage vector V, and the power factor is represented by cos θ. In the vector diagram of FIG. 6, by making the power factor angle θ as close as possible to 0 ° (cos θ = 1) and reducing the phase difference between the voltage vector V and the current vector I, the apparent power and the effective power can be reduced. It becomes almost equal and an ideal power factor can be obtained.

  Also, δ in the figure represents the lead phase angle [rad] from the d-axis of the armature flux linkage vector λ. The phase of the armature voltage vector V always advances by 90 ° with respect to the armature flux linkage vector λ as shown in the figure. Therefore, in order to reduce the power factor angle θ as described above, the armature linkage magnetic flux vector λ may be brought close to the magnet magnetic flux Ψa by reducing the phase angle δ. The inductance Lq in the Ld and q-axis directions may be reduced.

  The devices made for this purpose will be described below with reference to the drawings.

  Returning to FIG. As can be seen from FIG. 3, the thickness Hmag of the permanent magnet 3 included in the rotor 2 in the present embodiment is equal to or greater than the embedding depth He of the permanent magnet 3. That is, the relationship of Hmag ≧ He is established between the thickness of the permanent magnet 3 and the arrangement of the permanent magnet 3 in the rotor 2. The embedding depth He is the shortest distance connecting the deepest position from the air gap 13 and the outer periphery of the rotor 2 on the outer peripheral side surface of the rotor 2 of the permanent magnet 3 as shown in the figure. In this embodiment, the distance between the outer periphery of the rotor 2 and the outer peripheral side surface of the permanent magnet 3 on the line (d-axis) connecting the magnetic pole center of the permanent magnet 3 and the rotation center of the rotor 2 is the embedded depth. Become HE.

  By having this relationship of “Hmag ≧ He”, the embedding depth of the permanent magnet 3 in the rotor 2 of the present embodiment is set to be shallow. Thereby, the inductances Ld and Lq are reduced. Further, the inductance Ld is further reduced by setting the magnet thickness of the permanent magnet 3 to be thick. As a result, the power factor angle θ in FIG. 6 is reduced, and the power factor can be improved.

  Next, the device made in the relationship between the area of the magnetic barriers 4 and 5 in the end surface perpendicular | vertical to the axial direction of the rotor 2 of this embodiment and the area of the permanent magnet 3 is demonstrated with reference to FIG. .

  The variable magnetic flux type rotating electrical machine according to the present embodiment includes the sum Sair of the areas of one magnetic barriers 4 and 5 formed on the q axis at the end surface perpendicular to the axial direction of the rotor 2 included in the rotor 2. The area Smag of one permanent magnet 3 arranged on the d-axis has a relationship of Sair ≧ Smag.

  By having the relationship “Sair ≧ Smag”, the magnetic barriers 4 and 5 disposed between the adjacent permanent magnets 3 on the rotor core 12 are relatively large with respect to the permanent magnets 3. Thereby, since the d-axis inductance Ld is reduced, the power factor angle θ in FIG. 6 is reduced, and the power factor can be improved.

  Next, the device made with respect to the number of turns (number of turns) of the stator winding 10 of this embodiment will be described with reference to FIG.

  As a general property of a rotating electrical machine, when the rotor rotates, a counter electromotive force is generated due to the action of a magnetic flux. This counter electromotive force acts as a load component with respect to the rotation direction of the rotor, particularly in a high-speed rotation region, and causes a decrease in the output of the rotating electrical machine. On the other hand, the magnetic flux generated in the stator winding by energizing the stator winding becomes a reaction magnetic flux with respect to the magnet magnetic flux. The amount of the reaction magnetic flux is proportional to the number of turns of the stator winding, and the amount of magnetic flux increases as the number of turns increases. Therefore, if the amount of magnetic flux generated in the stator winding can be set to the amount of magnetic flux that can cancel the magnetic flux by optimizing the number of turns of the stator winding, the back electromotive force caused by the influence of the magnet magnetic flux can be set. Power can be canceled out. That is, if the number of turns of the stator winding can be optimized, a constant output characteristic can be realized in the high-speed rotation region, and the output can be increased.

  Here, when the d-axis linkage magnetic flux is λd, the magnet magnetic flux is ψa, the d-axis inductance is Ld, and the d-axis current is Id, the relationship λd = ψa + LdId is established. When the number of turns of the stator winding is N, the d-axis flux linkage λd can be expressed as λd (N) = Ψa + LdId (N) as a function of the stator winding. Thus, at the time of the maximum field weakening in the high-speed rotation region, by setting λd (N) = Ψa + LdId (N) = 0, the magnetic flux generated by the stator winding can be canceled, and the reverse The electromotive force can be canceled out. Since the field is weakest at the maximum, the d-axis current Id in the above formula is negative.

  FIGS. 7A and 7B are diagrams showing the relationship between the number of turns (number of turns) of the stator winding 10 and the d-axis linkage magnetic flux λd. The horizontal axis represents the number of turns N of the stator winding 10, and the vertical axis represents the d-axis linkage magnetic flux λd. As described above, the counter electromotive force can be canceled by winding the stator winding 10 with the number of turns such that λd (N) = 0 at the time of maximum field weakening. However, as shown in FIG. It is practically difficult to wind the stator winding 10 with the number of turns (N) where N) = 0. Therefore, the stator winding 10 of the variable magnetic flux rotating electric machine according to the present embodiment has λd (N) × λd (N + 1) ≦ 0 at the time of maximum field weakening in order to make λd (N) as close to 0 as possible. (See FIG. 7A) or λd (N) × λd (N−1) ≦ 0 (see FIG. 7B).

  As described above, the variable magnetic flux rotating electric machine according to the present embodiment has a relationship of “λd (N) × λd (N ± 1) ≦ 0” where N is the number of turns of the stator winding 10. The counter electromotive force generated due to the magnet magnetic flux can be suppressed, and the constant output characteristics in the high speed rotation region can be realized. As a result, the output of the rotating electrical machine is improved and the efficiency with respect to the input power can be increased.

  Next, on the rotor core 12 of the present embodiment, the device made for the magnetic flux bypass path 6, the shape of the bridge-shaped portion 7, the arrangement of the permanent magnets 3, and the like will be described with reference to FIG. 8. .

  FIG. 8 is a configuration diagram viewed from a plane perpendicular to the axial direction of the variable magnetic flux rotating electric machine according to the first embodiment, and is an enlarged view of FIG. 1 around the d-axis shown in FIG.

  A width C shown in FIG. 8 indicates a width of the magnetic flux inflow / outflow portion 14 of the magnetic flux bypass path 6 in the radial direction of the rotor 2.

  A width B shown in FIG. 8 indicates a width of a portion sandwiched between the magnetic barriers 4 and 5 in the magnetic flux bypass path 6.

  A width A shown in FIG. 8 indicates the width of the bridge-shaped portion 7 formed on the rotor core 12 on the outer peripheral side of the magnetic barrier 4 and connected to the magnetic flux bypass path 6.

  A width D shown in FIG. 8 is a distance (embedding depth) from the outer peripheral surface of the rotor 2 to the outer peripheral side surface of the rotor 2 of the permanent magnet 3, and the circumferential direction of the permanent magnet 3 in the rotor 2. The embedding depth of the end is shown.

  Assuming the above, the magnetic barrier 5 included in the variable magnetic flux rotating electric machine according to the present embodiment has the embedded depth D of the permanent magnet 3 and the magnetic flux inflow of the magnetic flux bypass path 6 in relation to the arrangement of the permanent magnet 3. The width C of the protruding portion 14 is substantially the same. In other words, the magnetic barrier 5 according to the present embodiment is arranged so that the relationship C≈D is established in relation to the permanent magnet 3.

  By having this relationship of “C≈D”, the amount of leakage flux of the d-axis magnetic flux leaking through the magnetic barrier 5 out of the magnetic flux emitted from the permanent magnet 3 can be reduced. Thereby, since the inductance Ld in the d-axis direction can be reduced, the power factor can be improved.

  Further, the width C of the magnetic flux inflow / outflow portion 14 of the magnetic flux bypass path 6 included in the variable magnetic flux type rotating electrical machine in the present embodiment, the width B of the portion sandwiched between the magnetic barriers 4 and 5, and the width A of the bridge-shaped portion 7 are as follows. , A + B ≦ C.

  Here, out of the magnetic flux emitted from the permanent magnet 3, the amount of leakage magnetic flux toward the different pole side constituted by the other adjacent permanent magnet 3 is substantially determined by the width C of the magnetic flux inflow / outflow portion 14 of the magnetic flux bypass path 6. If, for example, the width A of the bridge-shaped portion 7 is large and the relationship of A + B> C is satisfied, Lq increases and the reluctance torque decreases because the width A of the bridge-shaped portion 7 is excessively large. Torque is reduced. Therefore, by having the relationship of “A + B ≦ C”, the magnetic path width more than necessary is eliminated in the portion sandwiched between the magnetic barriers 4 and 5 of the magnetic flux bypass path 6 and the bridge-shaped portion 7. It is possible to suppress a decrease in torque and power factor caused by an increase in the width of the bridge-shaped portion 7.

  Furthermore, the width B of the portion sandwiched between the magnetic barriers 4 and 5 of the magnetic flux bypass path 6 of the variable magnetic flux rotating electric machine in the present embodiment and the width A of the bridge-shaped portion 7 have a relationship of A ≦ B. Formed.

  By having the relationship of “A ≦ B”, the width of the bridge-shaped portion 7 is set small, the increase of the inductance Lq can be prevented, and the salient pole ratio with the inductance Ld can be increased, so that the reluctance torque is improved. Can be made.

  As described above, the variable magnetic flux rotating electrical machine 100 according to the first embodiment includes the stator 1 having the stator winding 10 for generating the rotating magnetic field, the plurality of permanent magnets 3 forming the d-axis magnetic path, and the permanent magnets. And a rotor 2 that forms an air gap 13 with the stator 1. The rotor 2 includes a magnetic flux bypass path 6 serving as a path through which a magnetic flux emitted from a permanent magnet 3 constituting one magnetic pole leaks to a magnetic pole side constituted by another adjacent permanent magnet 3, and a d-axis magnetic path and an electric On the q-axis magnetic path perpendicular to the magnetic flux path, the magnetic barrier 4 provided between the magnetic flux bypass path 6 and the air gap 13, and the q-axis magnetic path electrically orthogonal to the d-axis magnetic path. The magnetic barrier 5 provided closer to the rotation center of the rotor than the bypass path, and the bridge-shaped portion 7 disposed between the magnetic barrier 4 and the air gap 13 so as to be connected to the magnetic flux inflow / outflow portion 14. And have. The thickness Hmag of the permanent magnet 3 in the d-axis magnetic path direction is equal to or greater than the embedding depth He from the outer peripheral surface of the rotor to the outer peripheral surface of the deepest permanent magnet. Thereby, since the inductance Ld in the d-axis direction and the Lq in the q-axis direction of the rotor 2 are reduced, the power factor can be improved.

  Further, the variable magnetic flux rotating electrical machine 100 according to the first embodiment includes the area of the magnetic barrier 4 and the area of the magnetic barrier 5 provided on one q-axis magnetic path in a plane perpendicular to the axial direction of the rotor 2. The sum Sair is equal to or larger than the area Smag of one permanent magnet. Thereby, since the inductance Ld of the d-axis direction in the rotor 2 is reduced, the power factor can be improved.

  The variable magnetic flux type rotating electrical machine 100 of the first embodiment has a stator winding 10 wound with a predetermined number of turns (N), and d-axis interlinkage magnetic flux acting on the stator winding 10 is λd. When expressed by the function (N), the stator winding 10 is wound with the number of turns that satisfies the relationship of “λ (N) × λd (N ± 1) ≦ 0” at the time of maximum field weakening. . Thereby, the counter electromotive force generated due to the magnet magnetic flux of the permanent magnet 3 can be suppressed, and the constant output characteristic in the high speed rotation region can be realized.

  The magnetic flux inflow / outflow part 14 of the magnetic flux bypass 6 included in the variable magnetic flux type rotating electrical machine 100 of the first embodiment is disposed in the vicinity of the air gap 13 of the rotor 2 and the stator 1 side of the magnetic barrier 5. It is a region formed between the end portion and the air gap, and the width C of the magnetic flux inflow / outflow portion 14 of the magnetic flux bypass path 6 and the circumferential end of the rotor 2 of the permanent magnet 3 from the outer peripheral surface of the rotor 2 The embedding depth D in the part is substantially the same. Thereby, since the inductance Ld of the d-axis direction in the rotor 2 can be reduced, the power factor can be improved.

  Further, in the variable magnetic flux rotating electric machine 100 of the first embodiment, the sum of the width A of the bridge-shaped portion 7 and the width B of the magnetic flux bypass path 6 in the region sandwiched between the magnetic barriers 4 and 5 It is less than the width C of the magnetic flux inflow / outflow portion of the path. Thereby, the fall of the torque and power factor which arise when the width | variety of the bridge-shaped part 7 becomes large can be suppressed, for example.

  Furthermore, the width A of the bridge-shaped portion 7 included in the variable magnetic flux rotating electric machine 100 of the first embodiment is equal to or smaller than the width B of the magnetic flux bypass path 6 in the region sandwiched between the magnetic barriers 4 and 5. Thereby, since the salient pole ratio of the rotor 2 can be increased, reluctance torque can be improved.

[Second Embodiment]
Next, the variable magnetic flux rotating electric machine according to the second embodiment will be described. The variable magnetic flux rotating electric machine according to the present embodiment is different from the first embodiment described above in the shape and arrangement of the permanent magnets 3 included in the rotor 2. Details will be described below with reference to the drawings.

  FIG. 9 is a configuration diagram viewed from a plane perpendicular to the axial direction of the variable magnetic flux rotating electric machine according to the second embodiment, and is a diagram for explaining the shape and arrangement of the permanent magnet 3.

  As shown in FIG. 9, the permanent magnet 3 included in the variable magnetic flux rotating electric machine in the present embodiment is divided into two in the circumferential direction of the rotor 2. And the center rib by the rotor core 12 is provided between the divided | segmented two permanent magnets 3a and 3b.

  Further, the dotted line in FIG. 9 is a line connecting the magnetic pole center of the magnetic pole constituted by the permanent magnets 3 a and 3 b and the rotation stop of the rotor 2. The solid line in the figure is a normal vector of the outer peripheral side surface (outer magnetic flux inflow / outflow surface) of the stator 2 in the permanent magnet 3b.

  And the permanent magnet 3b is arrange | positioned so that the angle | corner which the said dotted line and a continuous line make may be settled in the range of 0-45 degrees. The permanent magnet 3a is arranged symmetrically with respect to the dotted line with the permanent magnet 3b, and the angle formed by the normal vector (not shown) of the magnetic flux inflow / outflow surface on the outer peripheral side of the permanent magnet 3a and the dotted line is also the permanent magnet 3a. Similarly to the above, it is arranged so as to be within the range of 0 to 45 °.

  As described above, the permanent magnets 3a and 3b according to the second embodiment are arranged in the rotor 2 in a V-shape in which the magnetic pole center portion is recessed toward the rotation center as compared with both end portions in the rotor circumferential direction. With this arrangement, the magnetic path in the q-axis direction can be expanded, so that the reluctance torque is improved, and the maximum torque can be improved by using the reluctance torque.

  In addition, although the example which divided | segmented the permanent magnet 3 into two of the permanent magnets 3a and 3b was demonstrated above, it is not necessarily limited to two, You may divide | segment into three or more. Even in this case, each of the divided permanent magnets has a line connecting the magnetic pole center of one magnetic pole constituted by each of the divided permanent magnets and the rotation center of the rotor 2, and a magnetic flux inflow / outflow surface on the outer peripheral side of each permanent magnet. These are arranged in a V shape so that the angle formed by the normal vector falls within the range of 0 to 45 °.

  Next, the arrangement of the permanent magnets 3a and 3b included in the variable magnetic flux rotating electric machine according to the second embodiment in relation to the number of magnetic poles of the rotor 2 will be described with reference to FIG.

  FIG. 10 is a configuration diagram seen from a plane perpendicular to the axial direction of the variable magnetic flux rotating electric machine according to the second embodiment, and is a diagram showing a quarter of the entire configuration. The angle β in the figure is the side of the permanent magnets 3a and 3b that is far from the d-axis in the circumferential direction of the rotor 2 and is the part closest to the air gap 13 (the permanent magnet 3a constituting one magnetic pole). 3b is an angle formed by a line (a one-dot chain line in the figure) connecting the outermost portion of 3b and the rotation center of the rotor 2.

  When the value obtained by dividing 360 by the number of magnetic poles formed on the rotor 2 is α, the permanent magnets 3a and 3b provided in the present embodiment have β / α in the range of 40 to 50%. Arranged to fit. In addition, since the variable magnetic flux type rotating electrical machine in the present embodiment has an 8-pole structure, α is 45. Therefore, the permanent magnets 3a and 3b are arranged so that the angle β falls within the range of 18 to 22.5 °.

  With this arrangement, as the number of magnetic poles of the rotor 2 increases, the distance between the leakage magnetic path flowing from the permanent magnets 3a and 3b to the magnetic flux inflow / outflow portion 14 of the magnetic flux bypass path 6 and the q axis decreases. Therefore, the leakage magnetic flux can be efficiently converted into the stator linkage magnetic flux with a small applied current to the stator winding 10.

  In the above description, the permanent magnet 3 is divided into two permanent magnets 3a and 3b. However, the permanent magnet 3 is not necessarily divided into two, and may not be divided. It may be divided into two or more. Even in such a case, an angle formed by a line connecting the outermost portion of the permanent magnet 3 constituting one magnetic pole and the rotation center of the rotor 2, or both ends of each permanent magnet divided into three or more An angle formed by a line connecting the outermost portion of the permanent magnet located at and the rotation center of the rotor 2 is an angle β.

  As described above, in the variable magnetic flux type permanent magnet 200 of the second embodiment, the permanent magnet 3 constituting one magnetic pole is divided into at least two or more in the circumferential direction of the rotor 2, and the divided permanent magnets 3a and 3b are divided. The angle formed between the line connecting the magnetic pole center of one magnetic pole and the rotation center of the rotor 2 and the normal vector of the magnetic flux inflow / outflow surface on the outer peripheral side of the rotor of the permanent magnets 3a and 3b is within 0-45 °. Are arranged as follows. Thereby, since the magnetic path in the q-axis direction can be expanded, the reluctance torque is improved, and the maximum torque can be improved by using the reluctance torque.

  In the variable magnetic flux type permanent magnet 200 of the second embodiment, a value obtained by dividing 360 by the number of magnetic poles of the rotor 2 is α, and the magnetic pole center of the permanent magnet 3 constituting one magnetic pole in the circumferential direction of the rotor 2 is used. If the angle formed by the line connecting the position closest to the air gap 13 and the rotation center of the rotor 2 is β, the permanent magnets 3a and 3b have β / α Is arranged to be 40 to 50%. As a result, the distance between the leakage magnetic path flowing from the permanent magnets 3a and 3b to the magnetic flux inflow / outflow portion 14 of the magnetic flux bypass path 6 and the q axis approaches, so that the leakage magnetic flux is reduced with a small applied current to the stator winding 10. It can be efficiently converted into a stator flux linkage.

  The present invention is not limited to the embodiment described above.

DESCRIPTION OF SYMBOLS 1 ... Stator 2 ... Rotor 3 ... Permanent magnet 4 ... Magnetic barrier 5 ... Magnetic barrier 6 ... Bypass path 7 ... Bridge shape part 10 ... Stator winding 13 ... Air gap 14 ... Magnetic flux inflow part, Magnetic flux outflow part

Claims (8)

A variable magnetic flux rotating electrical machine,
A stator having a stator winding for generating a rotating magnetic field;
a rotor that has a plurality of permanent magnets forming a d-axis magnetic path and a magnetic circuit shape that is substantially symmetrical with respect to the magnetic pole center of the permanent magnet, and that forms an air gap with the stator; With
The rotor is
A bypass path serving as a path through which the magnetic flux emitted from the permanent magnet constituting one magnetic pole leaks to the magnetic pole side constituted by another adjacent permanent magnet;
A first magnetic barrier located on a q-axis magnetic path electrically orthogonal to the d-axis magnetic path and provided between the bypass path and the air gap;
A second magnetic barrier on a q-axis magnetic path electrically orthogonal to the d-axis magnetic path and provided closer to the rotation center of the rotor than the bypass path;
A bridge-shaped portion that is disposed between the first magnetic barrier and the air gap and connects the magnetic flux inflow portion and the magnetic flux outflow portion of the bypass path;
The thickness of the permanent magnet in the direction of the d-axis magnetic path is equal to or greater than the embedding depth from the outer peripheral surface of the rotor to the outer peripheral surface of the deepest permanent magnet.
A variable magnetic flux type rotating electrical machine characterized by that. The variable magnetic flux rotating electric machine according to claim 1,
The sum of the area of the first magnetic barrier and the area of the second magnetic barrier provided on one q-axis magnetic path in a plane perpendicular to the axial direction of the rotor is the permanent magnet. More than the area of one pole,
A variable magnetic flux type rotating electrical machine characterized by that. The variable magnetic flux rotating electrical machine according to claim 1 or 2,
The stator has a stator winding wound with a predetermined number of turns (N),
When the d-axis interlinkage magnetic flux acting on the stator winding is expressed by a function of λd (N), the stator winding has a number of turns that satisfies the following expression (1) at the time of maximum field weakening. To be
A variable magnetic flux type rotating electrical machine characterized by that.
[Equation 1]
λd (N) × λd (N ± 1) ≦ 0 (1) A variable magnetic flux rotating electrical machine according to any one of claims 1 to 3,
The magnetic flux inflow portion and the magnetic flux outflow portion of the bypass path are disposed in the vicinity of the air gap of the rotor, and are formed between the stator side end of the second magnetic barrier and the air gap. An area,
The width of the magnetic flux inflow portion and the magnetic flux outflow portion of the bypass path and the embedding depth from the outer peripheral surface of the rotor to the circumferential end of the permanent magnet of the permanent magnet are substantially the same.
A variable magnetic flux type rotating electrical machine characterized by that. The variable magnetic flux rotating electric machine according to claim 4,
The sum of the width of the bridge-shaped portion and the width of the bypass path in the region sandwiched between the first magnetic barrier and the second magnetic barrier is the magnetic flux inflow portion and the magnetic flux outflow of the bypass path. Less than or equal to the width of the part,
A variable magnetic flux type rotating electrical machine characterized by that. The variable magnetic flux rotating electric machine according to claim 5,
The width of the bridge-shaped portion is equal to or less than the width of the bypass path in a region sandwiched between the first magnetic barrier and the second magnetic barrier.
A variable magnetic flux type rotating electrical machine characterized by that. A variable magnetic flux rotating electrical machine according to any one of claims 1 to 6,
The permanent magnet constituting one magnetic pole is divided into at least two or more in the circumferential direction of the rotor;
Each of the divided permanent magnets has a line connecting the magnetic pole center of the one magnetic pole and the rotation center of the rotor, and a normal vector of a magnetic flux inflow / outflow surface on the outer peripheral side of the rotor of each of the divided permanent magnets. It is arranged so that the angle formed is within 0-45 °.
A variable magnetic flux type rotating electrical machine characterized by that. A variable magnetic flux rotating electrical machine according to any one of claims 1 to 7,
A value obtained by dividing 360 by the number of magnetic poles of the rotor is α,
A line that is a side surface far from the magnetic pole center of the permanent magnet constituting one magnetic pole in the circumferential direction of the rotor and that is closest to the air gap on the side surface and the rotation center of the rotor. If the angle formed by is β,
The permanent magnet is arranged so that β / α is 40 to 50%.
A variable magnetic flux type rotating electrical machine characterized by that.

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