JP5569135B2 - Rotating electrical machine equipment - Google Patents

Description

  The present invention relates to a rotating electrical machine apparatus using an axial gap rotating electrical machine, and more particularly to a technique for controlling a force applied to a rotating shaft in a rotating shaft direction.

  Generally, an axial gap type rotating electrical machine generates a larger magnetic attractive force in the direction of the rotation axis than a radial gap type rotating electrical machine. As a countermeasure, there is an axial gap type rotating electrical machine in which stators are arranged on both sides of the rotor rotation axis to cancel the magnetic attractive force in the rotation axis direction applied to the rotor. The axial gap type rotating electrical machine includes a rotating shaft, a rotor, and first and second stators. The rotating shaft is arranged so that movement in the direction of the rotating shaft is restricted during the rotation of the rotating shaft. The rotor has a plurality of field members arranged concentrically on the rotating shaft and arranged in an annular shape around the rotating shaft. The first stator is disposed on one side of the rotation axis direction with respect to the rotor, and a plurality of winding cores are disposed on the surface of the rotor so as to face the plurality of field members. Has been. A 2nd stator is a magnetic body arrange | positioned with respect to the rotor at the other side of the said rotating shaft direction.

  In such an axial gap type rotating electrical machine, a magnetic force is generated between the first and second stators and the rotor when current is selectively passed through the cores of the winding cores. The rotor is rotationally controlled by the magnetic force.

  An example of such an axial gap type rotating electrical machine is described in Patent Document 1.

JP 2008-187863 A

  The magnetic force generated between the first and second stators and the rotor includes a component in the rotation axis direction. For this reason, there is a drawback that the rotation shaft is pushed in the rotation axis direction by the component in the rotation axis direction, and bearing loss occurs in the bearing of the rotation shaft.

  An object of the present invention is to solve the above problems, and an axial gap that can reduce bearing loss of a rotating shaft only by controlling a current flowing through a winding of a magnetic core with each winding. The object is to provide a rotary electric machine.

In order to solve the above-described problem, a first aspect of the present invention includes a rotary shaft (40) disposed so as to be rotatable about the rotation axis Q1 while being restricted from moving in the direction of the rotation axis (Q1). A plurality of field members (10i) arranged annularly around the rotation axis, and a rotor (10) fixed to the rotation shaft; and one side of the rotation axis direction with respect to the rotor ( Q-), and a first stator having a plurality of winding cores (20b) disposed on the rotor side surface (20d) so as to face the plurality of field members. 20) and a second stator (30) that is a magnetic body disposed on the other side (Q +) in the direction of the rotation axis with respect to the rotor, the axial gap type rotating electrical machine (90), Inverter means (80) for selectively passing a current through the winding (20a) of the magnetic core with each winding; Control means (100) for controlling the rotation of the rotor by selectively supplying current to each of the windings by controlling the inverter means, and the first and second stators and the rotor. The component in the direction of the rotation axis of the resultant force of the magnetic force acting in between is controlled so as to selectively take a value between a positive value and a negative value, with the direction from the one side to the other side being positive. The means (100) controls the inverter means, and the axial gap type rotating electric machine (90) is such that the total force (F1) becomes a negative value (Fs) when the windings (20a) are not energized. Is set to

  A second aspect of the present invention is the rotating electrical machine apparatus according to the first aspect, in which the control means (100) controls the inverter means (80) and flows through each winding (20a). By controlling the current value and the phase angle (β), the component in the direction of the rotation axis (Q1) of the resultant force is selectively set to a value between the positive value and the negative value.

A third aspect of the present invention is the rotating electrical machine apparatus according to the first or second aspect, wherein the control means (100) is configured so that the absolute value of the total force (F1) is a minimum value. The rotation of the rotor (10) is controlled .

A fourth aspect of the present invention is the rotating electrical machine apparatus according to any one of the first to third aspects, wherein the d-axis is a d-axis current along the direction of the field magnetic flux of the field member. The inverter means is controlled based on a current command value and a q-axis current command value for a q-axis current orthogonal to the d-axis, and the d-axis current command value depends on the q-axis current command value. It is to be decided .

According to the first and fourth aspects of the present invention, the component (thrust force) of the resultant force in the direction of the rotation axis Q1 can selectively take a value between a positive value and a negative value. And the total force that is the sum of the components of the rotor 10 in the direction of the rotation axis Q1 can be controlled to the minimum value under the output torque of the motor 90. Moreover, since the total force (F1) is set to be a negative value (Fs) in the non-energized state of each winding (20a), for example, the total force is set to be a positive value. It is possible to set the phase angle (β) for making the value zero to be smaller.

  According to the second aspect of the present invention, the component of the resultant force in the direction of the rotation axis Q1 can be controlled only by controlling the current value and the phase angle.

According to the third aspect of the present invention, the bearing loss of the rotating shaft (40) due to the total force (F1) can be reduced to the minimum.

1 is a schematic configuration diagram of a rotating electrical machine apparatus according to an embodiment of the present invention. It is sectional drawing of the motor 90 of FIG. It is a disassembled perspective view of the 1st and 2nd stator and rotor of the motor 90 of FIG. It is an actual measurement figure which shows the relationship between total force F1, output torque T, and current phase angle (beta). FIG. 6 is an example of a correlation between an output torque T of a motor 90 and a current phase angle β. FIG. 6 is a correlation diagram between output torque T of motor 90, q-axis current command value Iq *, and d-axis current command value Id *, corresponding to the correlation of FIG. FIG. 6 is a correlation diagram between the output torque T of the motor 90 and the absolute values Ia of the respective currents Iu, Iv, Iw corresponding to the correlation of FIG. 5. It is an example of the correlation between the rotational speed ω and the output torque T of the motor 90. It is a correlation diagram which shows the relationship between the output torque T and the total force F1.

<First Embodiment>
As shown in FIG. 1, the rotating electrical machine apparatus 1 according to this embodiment converts a DC power source 70, a three-phase motor 90, and DC power of the DC power source 70 into three-phase AC power to convert each phase of the three-phase motor 90. An inverter circuit (inverter means) 80 that supplies current to U, V, and W, a plurality of current sensors 120u, 120v, and 120w that detect currents Iu, Iv, and Iw flowing in the respective phases, and current sensors 120u and 120v , 120w, and a control circuit (control means) 100 for controlling the inverter circuit 80 based on the detection result. The direct current power source may be formed by an alternating current power source and a converter.

  2 and 3, the motor 90 has the stators 20 and 30 arranged on both sides of the rotor 10, and the rotor 10 is restricted from moving in the direction of the rotation axis Q1 while being centered on the rotation axis Q1. This is a sensorless type axial gap type rotating electrical machine having a structure that is rotatably arranged. More specifically, as shown in FIGS. 2 and 3, the motor 90 includes the rotor 10, the first and second stators 20 and 30, the rotation shaft 40, and the first and second bearings 50 and 51. And a housing 60.

  The housing 60 is formed in a box shape, and each component 10, 20, 30, 40, 50, 51 is accommodated therein. Holes 60b and 60d are formed in the one surface 60a and the opposite surface 60c of the housing 60, respectively, and the rotation shaft 40 is inserted through the holes 60b and 60d so as to be rotatable around the rotation axis Q1. Is done.

  The rotor 10 includes a plurality of field members 10i, a plurality of core members 10f, a holding member 10h, and a steel plate 10g.

  The field members 10i are annularly arranged apart from each other around the rotation axis Q1. Each field portion 10i is formed, for example, in a substantially trapezoidal plate shape in plan view, and includes a field magnet 10a and a core member 10c.

  The field magnet 10a is a rare earth magnet whose main component is, for example, neodymium, iron, or boron. The field magnet 10a is formed in, for example, a substantially trapezoidal plate shape in plan view. Here, the side 10a3 corresponding to the lower base of the substantially trapezoidal shape of the field magnet 10a is convexly formed on the outer peripheral side in an arc shape. In the field magnet 10a, main surfaces 10a1 and 10a2 on both sides thereof are magnetic pole surfaces. Each field magnet 10a has its principal surfaces 10a1 and 10a2 on both sides thereof substantially orthogonal to the direction of the rotation axis Q1 and the side 10a3 corresponding to the bottom of the field magnet 10a faces the outside so that they are mutually connected around the rotation axis Q1. Spaced apart. In addition, each field magnet 10a has the polarity of the magnetic pole of the main surface (for example, main surface 10a1) on the same side (for example, the Q-side in the direction of the rotation axis Q1) alternately along the circumferential direction Q2 with respect to the rotation axis Q1. Arranged differently.

  The core member 10c is formed of a magnetic material (for example, a soft magnetic material such as iron) into a plate shape that is the same shape and size as the field magnet 10a in plan view (here, substantially trapezoidal). The core member 10c is disposed on one main surface 10a1 of the field magnet 10a.

  Each core member 10f is formed, for example, in a substantially rectangular parallelepiped shape from a magnetic material (for example, a soft magnetic material such as iron). Each core member 10f is disposed between adjacent field member 10i so that the longitudinal direction thereof is along the radial direction Q3 with respect to the rotation axis Q1.

  The holding member 10h holds the plurality of field members 10i and the plurality of core members 10f. The holding member 10h is made of a nonmagnetic material, such as a nonmagnetic metal, and includes an inner peripheral frame portion 10j, an outer peripheral frame portion 10k, and a plurality of connecting portions 10m.

  The inner peripheral frame portion 10j is formed in an annular shape (for example, a substantially annular plate shape). Here, the outer peripheral shape of the inner peripheral frame portion 10j is formed in, for example, a substantially hexagonal shape in a plan view viewed along the direction of the rotation axis Q1. The outer peripheral frame portion 10k is formed in an annular shape (for example, an annular shape), and is arranged concentrically on the outer peripheral side of the inner peripheral frame portion 10j. A rotating shaft 40 is inserted into a central hole 10n of the inner peripheral frame portion 10j in a concentric shaft shape and fixed.

  The rotation shaft 40 has one side Q− in the direction of the rotation axis Q <b> 1 supported by the first bearing 50 and the other side Q + in the rotation axis direction Q <b> 1 supported by the second bearing 51. More specifically, each of the first and second bearings 50 and 51 is fixed to the housing 60, supports the rotary shaft 40 so as to be rotatable about the rotary axis Q1, and moves in the direction of the rotary axis Q1. Supports to regulate. Thus, the rotation shaft 40 is supported by the bearings 50 and 51, so that the rotor 10 is rotatably arranged around the rotation axis Q1 while being restricted from moving in the direction of the rotation axis Q1.

  Here, each of the first bearing 50 and the second bearing 51 is, for example, a rolling bearing (that is, a bearing whose frictional resistance is reduced by using rolling of a rolling element disposed between an inner diameter portion and an outer diameter portion, Specifically, for example, it is configured as a ball bearing). Then, the rotary shaft 40 is fixed by being press-fitted into the inner diameter portions of the first bearing 50 and the second bearing 51 in an insertion manner. As a result, the first bearing 50 and the second bearing 51 are arranged so as to be rotatable around the rotation axis Q1 and restricted in the direction of the rotation axis Q1 with respect to the rotation shaft 40 as described above. The A recess 60h is formed in the inner surface 60g on one side Q- of the housing 60, and the outer diameter portion of the first bearing 50 is pressed into the recess 60h, so that it moves in the direction of the rotation axis Q1 and the radial direction Q3. It arrange | positions in the housing 60 so that it may not. Similarly, a recess 60f is formed in the inner surface 60e of the other side Q + of the housing 60, and the outer diameter portion of the second bearing 50 is press-fitted into the recess 60f, so that the rotation shaft Q1 direction and the radial direction Q3 It arrange | positions at the housing 60 so that it may not move. The hole 60b is formed at the bottom of the recess 60h, and the hole 60d is formed at the bottom of the recess 60d.

  Each connecting portion 10m is arranged along the radial direction Q3 between the inner peripheral frame portion 10j and the outer peripheral frame portion 10m, and connects the inner peripheral frame portion 10j and the outer peripheral frame portion 10m. As for the interval between the adjacent connecting portions 10m, a relatively small interval and a relatively large interval are alternately repeated along the circumferential direction Q2. A core member 10f is fitted and disposed in the section 10p1 corresponding to the relatively small interval, and a field member 10i is fitted and disposed in the space 10p2 corresponding to the relatively large interval.

  That is, the field members 10i are annularly arranged around the rotation axis Q1, and the main surface 10a2 on one side Q + of the field magnet 10a is exposed from the main surface 10h2 on the same side Q + of the holding member 10h. In addition, the main surface (magnetic pole surface) 10c1 on the other side Q− of the core member 10c is disposed on the holding member 10h in a state of being exposed from the main surface 10h1 on the same side Q− of the holding member 10h. The core member 10f is disposed between adjacent field member 10i so as to penetrate between the main surfaces 10h1 and 10h2 on both sides of the holding member 10h.

  The steel plate 10g is formed, for example, in a substantially annular plate shape (for example, an annular plate shape) by a magnetic material (for example, a soft magnetic material such as iron), and the holding member is covered so as to cover the main surface 10a2 of each field magnet 10a. It is arranged concentrically on the surface of one side Q + of 10h.

  The first stator 20 includes, for example, a back yoke 20c and a plurality of winding cores 20e. For example, the first stator 20 is fixed to the housing 60 between the rotor 10 and the first bearing 50.

  The back yoke 20c is formed in, for example, a substantially annular plate shape (for example, an annular plate shape), and the rotation shaft 40 is inserted through the center hole 20f so as to be rotatable around the rotation axis Q1. The back yoke 20 c is disposed between the rotor 10 and the first bearing 50 by being fixed to the housing 60 so as to be disposed concentrically with the rotor 10.

  Each winding core 20e includes an armature core 20b and an armature winding 20a. The armature core 20b is formed in a substantially trapezoidal column shape, for example, and an armature winding 20a is wound around the outer periphery thereof. A plurality of armature cores 20b are annularly arranged around the rotation axis Q1 so that the side surface 20b3 facing the lower base of the substantially trapezoidal shape faces the outside on the main surface 20d of the back yoke 20c on the rotor 10 side. Has been. Note that the armature core 20b includes, for example, a substantially trapezoidal columnar magnetic core body 20b1 around which the armature winding 20a is wound, and the surface of the magnetic core body 20b1 on the rotor 10 side. For example, it has a substantially trapezoidal plate-like wide magnetic core portion 20b2 formed integrally with the magnetic core main body portion 20b1 so as to project to the outer peripheral side.

  The armature winding 20a is wound around the outer periphery of the armature core 20b via an insulator (not shown). In the present application, unless otherwise specified, the armature winding 20a does not indicate one of the conductive wires constituting the armature winding 20a, but indicates a mode in which the conductive wires are wound together. Further, the lead lines at the beginning and the end of the winding, and their connection are also omitted in the drawings. Each armature winding 20 a is connected to be wired so as to constitute a motor 90 and is connected to electrodes 11 u, 11 v, 11 w for each phase U, V, W provided in the motor 90.

  The second stator 30 is formed of a magnetic material, for example, in a substantially ring plate shape (for example, an annular plate shape), and the rotation shaft 40 is inserted into the center hole 30c so as to be rotatable around the rotation axis Q1. . For example, the second stator 30 is disposed between the rotor 10 and the second bearing 50 by being fixed to the housing 60 so as to be disposed concentrically with the rotor 10.

  In this motor 90, each armature winding 20a is excited by supplying current from the inverter circuit 80 to each armature winding 20a via the electrodes 11u, 11v, 11w of the respective phases U, V, W. The A magnetic attractive force or a magnetic repulsive force is generated between the excited armature winding 20a and each field member 10i of the rotor 10, and the rotor 10 is rotated about the rotation axis Q1 by these forces, and this rotation A force is output to the outside through the rotating shaft 40.

  Here, the motor 90 is disposed so that the rotation axis Q1 is horizontal (that is, the component of the motor 90 in the direction of the rotation axis Q1 is zero).

  As shown in FIG. 4, the motor 90 has a magnetic force acting between the rotor 10 and the first stator 20 and the second stator 30 when the motor 90 is not energized (that is, when the motor 90 is stopped). A component of the resultant force in the direction of the rotation axis Q1 (hereinafter referred to as thrust force) and a component in the direction of the rotation axis Q1 other than the magnetic force acting on the rotor 10 (for example, the rotation axis Q1 of the rotor 10 due to its own weight) The total force F1 with the direction component (in this embodiment, this component is zero)) is designed to be a negative value (initial value) Fs (Fs≈−80 in FIG. 4). Further, in the energized state of the motor 90 (that is, the rotating state of the motor 90), when the output torque of the motor 90 is equal to or greater than a predetermined value, the total force F1 according to the phase angle β of the currents Iu, Iv, Iw flowing through the windings 20a Is designed to change from a positive value to a negative value. The total force F1 is positive in the direction from one side (second stator 30 side) Q + to the other side (first stator 20 side) Q− in the direction of the rotation axis Q1.

  In the above design, for example, the distances d1 and d2 between the rotor 10 and the first stator 20 and the second stator 30 may be adjusted, and the thickness of the steel plate 10g may be adjusted. The shape or material of each of the surface 20g on the rotor 10 side of the magnetic core 20e and the surface 30a on the rotor 10 side of the second stator 30 may be changed, and the magnetic flux density on each surface 20g, 30a may be changed. The surfaces 20g and 30a may be inclined with respect to the direction of the rotation axis Q1 (in this embodiment, the surfaces 20g and 30a are orthogonal to the direction of the rotation axis Q1). .

  In FIG. 4, when the output torque of the motor 90 is 0 [Nm] (no load state) (graph g5), 0.5 [Nm] (graph g4), and 1.0 [Nm] ( The relationship between the total force F1 and the phase angle β is shown for graphs g3), 2.0 [Nm] (graph g2) and 3.0 [Nm] (graph g1). When the output torque of the motor 90 is 1.0 [Nm] and 2.0 [Nm], the total force F1 changes from a positive value to a negative value according to the phase angle β, and is 0.5 [Nm. ] And 1.0 [Nm], the total force F1 is designed to be negative over the entire range of the phase angle β.

  As shown in FIG. 1, the inverter circuit 80 includes a plurality (six in this case) of switch elements SU1, SU2, SV1, SV2, SW1, and SW2. Each switch element SU1, SU2 is connected between the anode and the cathode of the DC power supply 70 in a state of being connected in series with each other, and the potential between them is applied to the U-phase electrode 11u of the three-phase load 90. The switch elements SV1 and SV2 are connected between the anode and the cathode of the DC power supply 70 in a state of being connected in series, and the potential between them is applied to the V-phase electrode 11v of the motor 90. The switch elements SW1 and SW2 are connected between the anode and the cathode of the DC power supply 70 in a state of being connected in series with each other, and the potential therebetween is applied to the W-phase electrode 11w of the motor 90.

  Each switch element SU1, SU2, SV1, SV2, SW1, SW2 includes a transistor T and a diode D provided between the main electrodes of the transistor T. The diode D is provided between the main electrodes of the transistor T so that the energization direction is opposite to the energization direction of the transistor T. The control electrode G of each switch element is connected to the control circuit 100. As the switch elements SU1, SU2, SV1, SV2, SW1, and SW2, an IGBT or the like including a reflux diode can be used.

  In the inverter circuit 80, a voltage is applied by the control circuit 100 to the control electrodes G of the switch elements SU1, SU2, SV1, SV2, SW1, SW2, and the conduction / non-conduction of these switch elements is controlled. As a result, the DC power of the DC power supply 70 is converted into three-phase AC power, current is supplied to the electrodes 11u, 11v, and 11w of the phases U, V, and W of the motor 90, and the motor 90 is rotationally driven.

  The control circuit 100 (i) so that the rotational speed ω of the motor 90 coincides with the rotational speed command value ω *, and (ii) so that the absolute value of the total force F1 becomes the minimum value in the rotational state of the motor 90. The inverter circuit 80 is controlled. In order to control the total force F1 as in (ii) above, the control circuit 100 controls the inverter circuit 80 to control the current values and phase angles β of the currents Iu, Iv, Iw flowing through the windings 20a. By doing so, the total force F1 is set so as to be able to selectively take a value between a positive value and a negative value.

Here, for simplification, it is assumed that the number of pole pairs Pn (Pn = 1 / 2PP: number of poles) of the motor 90 is 1. As a result, the mechanical rotational speed ω becomes equal to the electrical rotational speed ωe. Since there is a relational expression of ωe = Pn · ω, when the number of pole pairs Pn is not limited to 1, for example, ωe = 4ω. Since the drive voltage is calculated by time differentiation of the magnetic flux amount and inductance, it is necessary to use the electrical rotation speed ωe. In this case, ω = ωe, and in particular, the mechanical rotation speed and the electric rotation speed are used. It explains without distinguishing. The unit of the rotational speed ω is [rad / s], which is precisely the rotational angular speed, and between the rotational speed N [r / s], ω = 2 · π · f f: frequency [Hz] There is a relationship. In the present description, unless otherwise specified, the rotational angular velocity is referred to as rotational speed ω. Here, for the following explanation, each constant on the dq axis model of the motor 90 is defined as follows. For details, see "Design and Control of Embedded Magnet Synchronous Motor", Yoji Takeda, Nobuyuki Matsui, Shigeo Morimoto, Yukio Honda Ohmsha, page 11.
φa: Permanent magnet flux linkage [wb]
Ld: Armature d-axis inductance [H]
Lq: Armature q-axis inductance [H]
Ra: Phase resistance [Ω]
Id: d-axis armature current [A]
Iq: q-axis armature current [A]
As shown in FIG. 1, the control circuit 100 includes a rotation speed command value generation unit 100j, a d-axis current command value generation unit 100d, a d-axis voltage command value generation unit 100e, a q-axis current command value generation unit 100f, q-axis voltage command value generation unit 100g, first coordinate conversion unit 100a, second coordinate conversion unit 100h, PWM signal generation unit 100i, third coordinate conversion unit 100b, and fourth coordinate conversion unit 100c, a position estimation output unit 100k, a rotation speed calculation unit 100m, and an initial rotation estimation unit 100q.

  The PWM signal generation unit 100i applies a PWM signal to each control electrode G of the inverter circuit 80 immediately before the rotation of the motor 90 is started, and the predetermined one of the electrodes 11u, 11v, 11w of the motor 90 from the inverter circuit 80 is applied. A predetermined voltage (for example, a high frequency voltage at which the motor 90 does not react) is applied to the two (for example, 11v, 11w). Thus, a voltage is generated at a predetermined one (for example, 11u) of the electrodes 11u, 11v, and 11w of the motor 90 in a state where the rotation of the motor 90 is stopped. Hereinafter, the phase to which the predetermined voltage is not applied is referred to as a non-conducting phase (here, U phase).

  The initial rotational position estimation unit 100q detects the initial rotational position θ0 of the rotor 20 using the detection result of the current sensor corresponding to the non-energized phase of the motor 90 and the voltage generated at the non-conducting phase electrode. More specifically, since the inductance of the motor 90 depends on the rotational position θ of the motor 90, the initial rotational position estimating unit 100q detects the detection result of the current sensor corresponding to the non-conduction phase and the voltage generated at the electrode of the non-conduction phase. From this, the inductance of the motor 90 is estimated, and the initial rotational position θ0 of the motor 90 is estimated from the estimated value.

  The third coordinate conversion unit 100b performs predetermined coordinate conversion on the currents Iv and Iw detected by the current sensors 120v and 120w (ie, from a three-axis three-dimensional coordinate system corresponding to each phase U, V, and W). The α-axis current Iα and the β-axis current Iβ are calculated by performing a coordinate conversion of the α-axis and the β-axis into a two-dimensional coordinate system (two-phase orthogonal stator coordinate system).

  The fourth coordinate conversion unit 100c performs predetermined coordinate conversion (that is, each phase U, V) with respect to a V-phase voltage command value Vv * and a W-phase voltage command value Vw * described later calculated by the second coordinate conversion unit 100h. Coordinate conversion from the three-axis three-dimensional coordinate system corresponding to V and W to the two-dimensional coordinate system (two-phase orthogonal stator coordinate system) of the α-axis and β-axis), and the α-axis voltage command value Vα * and A β-axis voltage Vβ * is calculated.

  The position estimation unit 100k includes an α-axis current Iα and a β-axis current Iβ calculated by the third coordinate conversion unit 100b, and an α-axis voltage command value Vα * and a β-axis voltage calculated by the fourth coordinate conversion unit 100c. Based on the command value Vβ *, a rotational position (position estimation value) θ during rotation of the motor 90 is calculated.

  The rotation speed calculation unit 100m is based on the initial rotation position θ0 estimated by the initial rotation position estimation unit 100g immediately before the rotation start of the motor 90, and when the motor 90 rotates, the rotation estimated by the position estimation unit 100k. Based on the position θ, the rotational speed ω of the motor 90 is calculated.

  The first coordinate conversion unit 100a performs the initial calculation calculated by the initial position estimation unit 100g immediately before the rotation of the motor 90 with respect to the currents Iu, Iv, and Iw detected by the current sensors 120u, 120v, and 120w. Using the rotational position θ0 and when the motor 90 rotates, the rotational position θ calculated by the position estimation unit 100k is used to perform predetermined coordinate transformation (that is, three-axis three-dimensional corresponding to each phase U, V, W). Coordinate conversion from a coordinate system to a two-dimensional coordinate system of d-axis and q-axis) is performed to calculate d-axis current Id and q-axis current Iq.

  The d-axis is an axis taken in the direction of the field magnetic flux that generates the N pole by the field magnet 10a, and the q-axis is an axis orthogonal to the d-axis on the advance side with respect to the rotation direction. It is. The d-axis current Id is a current component that contributes to the d-axis direction of a magnetic field (armature magnetic field) generated by excitation of the armature winding 20a, and the q-axis current Iq is generated by excitation of the armature winding 20a. It is a current component that contributes to the q-axis direction of the magnetic field.

  The rotation speed command value generation unit 100j generates a rotation speed command value ω * for rotating the motor 90 at a desired rotation speed ω.

  The q-axis current command value generation unit 100f is configured such that the rotation speed ω calculated by the rotation speed calculation unit 100m approaches the rotation speed command value ω * from the rotation speed command value generation unit 100j. * Is generated. Specifically, the q-axis current command value generation unit 100f generates a q-axis current command value Iq * by performing a proportional-integral calculation (PI control) on the deviation between the rotation speed ω and the rotation speed command value ω *.

  The d-axis current command value generation unit 100d corresponds to the q-axis current command value Iq * generated by the q-axis current command value generation unit 100f in accordance with the rotation speed command value ω * from the rotation speed command value generation unit 100j. The d-axis current command value Id * is generated so that the absolute value of the total force F1 becomes the minimum value under the output torque of the motor 90.

The q-axis voltage command value generation unit 100g is configured such that the q-axis current Iq calculated by the first coordinate conversion unit 100a approaches the q-axis current command value Iq * generated by the q-axis current command value generation unit 100f. , Q-axis voltage command value Vq * is generated. From the equation (1.6) on page 11 of the previous reference, the term of the differential operator p = d / dt can be ignored in the voltage equation in the steady state, and the d-axis voltage Vd and the q-axis voltage are expressed by the following equations (1) and (2)
Vd = RaId−ωLqIq (1)
Vq = RaIq + ωLdId + ωφa (2)
Therefore, specifically, the q-axis voltage command value generation unit 100g obtains the first term RaIq that is the voltage drop in the above equation (2), and the voltage as the time differential value of the d-axis armature magnetic flux LdId. The value ωLdId is obtained, ωφa which is a time derivative of the permanent magnet linkage magnetic flux φa is obtained, and these are added together to generate the q-axis voltage command value Vq *.

  The d-axis voltage command value generation unit 100e is configured such that the d-axis current Id calculated by the first coordinate conversion unit 100a approaches the d-axis current command value Id * generated by the d-axis current command value generation unit 100d. , D-axis voltage command value Vd * is generated. Specifically, the d-axis voltage command value generation unit 100e obtains the first term RaId that is a voltage drop in the above equation (1), and the voltage value ωLqIq as a time differential value of the q-axis armature magnetic flux LqIq. And the d-axis voltage command value Vd * is generated by taking the difference between the first term and the second term.

  The second coordinate conversion 100h is performed on the motor 90 with respect to the d-axis voltage command value Vd * and the q-axis voltage command value Vq * generated by the d-axis voltage command value generation unit 100e and the q-axis voltage command value generation unit 100g. Before starting the rotation, a predetermined coordinate transformation (ie, using the initial rotational position θ0 calculated by the initial position estimation unit 100g and using the rotational position θ calculated by the position estimation unit 100k when the motor 90 rotates). (coordinate conversion from a two-dimensional coordinate system of d-axis and q-axis to a three-dimensional three-dimensional coordinate system corresponding to each phase U, V, W), U-phase voltage command value Vu *, V-phase voltage command value Vv * and W-phase voltage command value Vw * are calculated. The amplitude is Vu *, Vv *, Vw *, and the frequency is a voltage command value of f (f = ω / (2π)).

  Further, the PWM signal generation unit 100i applies a PWM signal to each control electrode G of the inverter circuit 80 during rotation of the motor 90, and performs third coordinate conversion on each phase electrode 11u, 11v, 11w of the motor 90, respectively. The inverter circuit 80 is controlled so that voltages that match the phase voltage command values Vu *, Vv *, and Vw * calculated by the unit 100b are applied. As a result, the rotational speed ω of the motor 90 is controlled to coincide with the rotational speed command value ω *.

  Next, based on FIGS. 5 to 8, the operation of the main part of the rotating electrical machine apparatus 1 (that is, the operation of the q-axis current command value generation unit 100f and the d-axis current command value generation unit 100d) will be mainly described. Hereinafter, a case where the rotational speed command value ω * increases from zero to the maximum rotational speed ωmax (that is, a case where the rotational speed ω of the motor 90 increases from zero to the maximum rotational speed ωmax) will be described as an example. In the following, for convenience of explanation, the motor 90 will be described as being used in a compressor, for example. The q-axis current Iq is limited to the range of Iqmin ≦ Iq ≦ Iqmax, the d-axis current Id is limited to the range of −Idmax ≦ Id ≦ Idmin, and the absolute values Ia of the currents Iu, Iv, and Iw are Iamin. It is assumed that the range is limited to a range of ≦ Ia ≦ Iamax.

  When the rotational speed command value ω * (and hence the rotational speed ω) is zero, the output torque T is zero as shown in FIG. 7, and therefore the absolute values Ia of the currents Iu, Iv, Iw are also zero. Therefore, as shown in FIG. 6, the d-axis current command value generation unit 100d sets the d-axis current command value Id * to zero so that the d-axis current Id becomes zero, and the q-axis current command value generation unit 100f In this way, the q-axis current command value Iq * is set to zero so that the q-axis current Iq becomes zero. As a result, the currents Iu, Iv, and Iw are controlled to zero, and the rotational speed ω of the motor 90 is controlled to zero (that is, the motor 90 is stopped). In this state, the total force F1 becomes a negative initial value Fs.

  The current phase angle depends on the output torque T of the motor 90 until the rotational speed command value ω * (and hence the rotational speed ω) increases and reaches the rotational speed ωL that reaches the upper limit of the input voltage of the control circuit 100. β is controlled as shown in FIG. In the case of a compressor, the compression torque for the rotational speed ω is arbitrarily determined by the refrigerant conditions, mechanical loss torque, etc., so that the q-axis current is ensured so as to ensure the necessary torque for maintaining the rotational speed command value ω *. Command Iq * is determined. More specifically, the q-axis current command value generation unit 100f determines that the q-axis current command value depends on the frequency of the rotation speed command value ω * when the rotation speed ω is smaller than the rotation speed command value ω *. When Iq * is increased and the rotational speed ω is larger than the rotational speed command value ω *, the q-axis current command value Iq * is decreased depending on the frequency of the rotational speed command value ω *. As a result, the q-axis current command value Iq * increases as the output torque T increases as shown in FIG. The d-axis current command generation unit 100d generates a d-axis current command value Id * corresponding to the q-axis current command value Iq * generated by the q-axis current command value generation unit 100f.

  Specifically, in the region of 0 <T ≦ T1 in FIG. 5, the d-axis current command value generation unit 100d performs d-axis current command value Id * in order to maintain the d-axis current Id at zero as shown in FIG. Is maintained at zero. As a result, the currents Iu, Iv, and Iw are controlled to current values that can maintain the rotational speed of the rotational speed command value ω * with the phase angle β = 0. Therefore, in this region (0 <Iq * ≦ Iq1 in this region), as shown in FIGS. 7 and 9, the output of the motor 90 is increased as the absolute value Ia of each current Iu, Iv, Iw increases. As the torque T increases, the total force F1 increases from the initial value Fs toward zero. In other words, since the total force F1 is a negative value in this region, control is performed so that β = 0 to maximize the total force F1. Thereby, the bearing loss in each bearing 50 and 51 resulting from the total force F1 is reduced to the minimum. Note that Iq1 and Id1 in FIG. 6 are the q-axis current value and the d-axis current value corresponding to the torque T1, respectively.

  Next, in the region of T1 <T ≦ T2 in FIG. 5, the d-axis current command value generation unit 100d performs d-axis current command value Id * (Id1 corresponding to the q-axis current command value Iq * as shown in FIG. (= 0) <Id * ≦ Id2) is generated. As a result, each of the currents Iu, Iv, and Iw has a phase angle β (0 ° <β ≦ 17 °) between T1 and T2 in FIG. 5 and a current value that can maintain the rotational speed of the rotational speed command value ω *. Be controlled. Therefore, in this region (in this region, Iq1 <Iq * ≦ Iq2), as shown in FIGS. As T increases, the total force F1 is almost always controlled to zero. Thereby, the bearing loss in each bearing 50 and 51 resulting from the total force F1 is reduced to the minimum. Note that Iq2 and Id2 in FIG. 6 are the q-axis current value and the d-axis current value corresponding to the torque T2, respectively.

  Next, in the region of T2 <T ≦ T3 in FIG. 5, the d-axis current command value generation unit 100d performs d-axis current command value Id * (Id2) corresponding to the q-axis current command value Iq * as shown in FIG. <Id * ≦ Id3) is generated. As a result, each of the currents Iu, Iv, and Iw has a phase angle β (17 ° <β ≦ 37 °) between T2 and T3 in FIG. 5 and a current value that can maintain the rotation speed of the rotation speed command value ω *. Be controlled. Therefore, in this region (Iq2 <Iq * ≦ Iq3 in this region), as shown in FIGS. 7 and 9, the output of the motor 90 is increased as the absolute value Ia of each current Iu, Iv, Iw increases. As the torque T increases, the total force F1 is almost always controlled to zero. Thereby, the bearing loss in each bearing 50 and 51 resulting from the total force F1 is reduced to the minimum. Note that Iq3 and Id3 in FIG. 6 are the q-axis current value and the d-axis current value corresponding to the torque T3, respectively.

  If the rotational speed ω (and hence the rotational speed command value ω *) is within the range from zero to ωL, the value of the output torque T with respect to the rotational speed ω can be freely selected. That is, the output torque can be increased together with the rotational speed ω as shown by line a in FIG. 8, and the maximum torque 3 Nm can be output immediately after the start of rotation as shown by line b. As described above, it is also arbitrary to raise and lower within a maximum torque of less than 3 Nm. Of course, the rotational speed ω can be accelerated, decelerated, or maintained at a constant speed, and the total force F1 can be controlled to a minimum in the entire region of the rotational speed ω.

  However, in the region where the required driving voltage of the motor 90 exceeds the upper limit of the input voltage of the control circuit 100 (that is, the region of ω> ωL), the induced voltage of the motor 90 is reduced by the magnetic flux weakening control. For example, in the line d in FIG. 8, the current phase angle β becomes β> 37 °, the total force F1 becomes a negative value again, and a thrust is gradually generated. Become.

  On the other hand, in the case of high-speed rotation with a torque obtained by subtracting the output torque from the maximum torque of 3 Nm, for example, in the case of line e or line f in FIG. 8, the values of Iq and Id are smaller than Iq3 and Id3, respectively. Both the d-axis armature reaction voltage −ω · Lq · Iq and the q-axis armature reaction voltage ω · Ld · Id are smaller than −ω · Lq · Iq3 and ω · Ld · Id3. As a result, the drive voltage at the maximum torque of 3 Nm has a margin, and as a result, high speed rotation is possible without much advance control of the current phase angle β, and each bearing 50 caused by the total force F1 continues. The minimum thrust control at 51 is possible.

  According to the rotating electrical machine apparatus 1 configured as described above, since the total force F1 can selectively take a value between a positive value and a negative value, the total force F1 is requested to the motor 90 by the selection. Can be controlled to the minimum value under the output torque. Thereby, the bearing loss in each bearing 50 and 51 resulting from the total force F1 can be reduced to the minimum value.

  Further, the total force F1 can be controlled by controlling the current values of the currents Iu, Iv, Iw flowing through the windings 20a and the phase angle β (that is, by simple control).

  In addition, in the non-energized state of the motor 90 (that is, the non-energized state of each winding 20b), the total force F1 is set to be a negative value Fs. The phase angle β for making the total force F1 zero can be set smaller.

  In this embodiment, the case where the rotation axis Q1 is horizontal has been described. However, when the rotation axis Q1 is not horizontal, only the component of the weight of the rotor 10 in the direction of the rotation axis Q1 is included in the total force F1. The above description of the operation is the same.

DESCRIPTION OF SYMBOLS 1 Rotating electrical machinery apparatus 10 Rotor 20 1st stator 20a Armature winding 30 2nd stator 40 Rotating shaft 80 Inverter circuit 90 Three-phase motor 100 Control circuit Q1 Rotating shaft

Claims (4)

A rotating shaft (40) disposed so as to be rotatable around the rotating shaft while being restricted from moving in the direction of the rotating shaft (Q1);
A rotor (10) having a plurality of field members (10i) arranged annularly around the rotation axis, and fixed to the rotation shaft;
A plurality of winding magnets are arranged on one side (Q-) in the rotation axis direction with respect to the rotor, and on the rotor side surface (20d) so as to face the plurality of field members. A first stator (20) provided with a core (20b);
A second stator (30) which is a magnetic body disposed on the other side (Q +) in the rotation axis direction with respect to the rotor;
An axial gap type rotating electrical machine (90) including:
Inverter means (80) for selectively passing a current through the winding (20a) of each of the magnetic cores with windings;
Control means (100) for controlling the inverter means to selectively flow a current to each winding to control the rotation of the rotor;
With
A component of the resultant magnetic force acting between the first and second stators and the rotor in the direction of the rotational axis, and a force other than the magnetic force acting on the rotor in the direction of the rotational axis. The control means (100) is configured so that the total force (F1) with the component takes a value between a positive value and a negative value, with the direction from the one side to the other side being positive. Control means ,
The axial gap type rotating electrical machine (90) is set so that the total force (F1) becomes a negative value (Fs) when the windings (20a) are not energized. . The rotating electrical machine apparatus according to claim 1,
The control means (100) controls the inverter means (80) to control the current value and phase angle (β) of the current flowing through the windings (20a), so that the total force (F1) is A rotating electrical machine apparatus that selectively takes a value between a positive value and the negative value. The rotating electrical machine apparatus according to claim 1 or 2,
The rotating electrical machine apparatus, wherein the control means (100) controls the rotation of the rotor (10) so that the absolute value of the total force (F1) becomes a minimum value . The rotating electrical machine apparatus according to any one of claims 1 to 3,
The control means (100) includes a d-axis current command value for the d-axis current along the direction of the field magnetic flux of the field member, and a q-axis current command value for the q-axis current orthogonal to the d-axis. And the d-axis current command value is determined according to the q-axis current command value .

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