ENGINE SYSTEM AND ENGINE

Abstract

A motor system includes a motor (1) and a control unit that controls the motor. The motor includes: a rotor (10) in which a magnetic flux generator that generates a magnetic flux is arranged; a stator (12) including a return yoke (13) arranged facing the rotor and a plurality of teeth (14) that project from the return yoke toward the rotor and are arranged adjacent to each other at intervals in a rotation direction of the rotor; a winding (16) wound around the stator; and a plurality of magnetic sensors (17-1 to 17-6) provided in slots (15), which are spaces between adjacent teeth, for measuring a magnetic flux density.The control unit includes a calculation unit that obtains a rotation angle and / or an eccentricity of the rotor based on signals from the plurality of magnetic sensors, and a magnetic sensor signal used by the calculation unit is a signal from the magnetic sensor provided in the slot in which the windings on both sides have the same phase and opposite directions of energization to each other.

Description

Area

[0001] The present disclosure relates to a motor system and a motor that detects the rotation angle and / or eccentricity of the motor using a magnetic sensor. General state of the art

[0002] Motors generate torque through the interaction between a current and a magnetic flux density. To detect the rotation angle or eccentricity of a motor, there is a method in which a magnetic flux generator that generates a magnetic flux, such as a permanent magnet or a field winding, is arranged in a rotor, and a magnetic flux density from the rotor is measured by a magnetic sensor and used for calculation.

[0003] For example, Patent Literature 1 discloses a motor including a rotor in which a permanent magnet is disposed and a magnetic sensor, which has a function of detecting the rotation angle of the motor. In the motor disclosed in Patent Literature 1, the magnetic sensor is arranged between a plurality of teeth around which windings are wound. List of citationsPatent literature

[0004] Patent Literature 1: Japanese Patent Application Laid-Open No. 2016-188700 Brief description of the inventionProblem to be solved by the invention

[0005] However, the magnetic sensor according to the motor disclosed in Patent Literature 1 can detect not only the magnetic flux generated by the permanent magnet arranged in the rotor, but also the magnetic flux generated in the winding when energized. This leads to a problem in that the signal of the magnetic sensor changes depending on the energization of the winding, and the detection error of the rotation angle or eccentricity may increase.

[0006] The present disclosure has been made in view of the foregoing, and an object thereof is to provide a motor system capable of reducing the detection error of information about a detection target, which is the rotation angle and / or the eccentricity. Ways to solve the problem

[0007] In order to solve the problems described above and achieve the object, a motor system according to the present disclosure comprises a motor and a control unit for controlling the motor, the motor including: a rotor in which a magnetic flux generator that generates a magnetic flux is disposed; a stator including a return yoke disposed facing the rotor and a plurality of teeth that protrude from the return yoke toward the rotor and are juxtaposed at intervals in a rotation direction of the rotor; a winding wound around the stator; and a plurality of magnetic sensors provided in slots that are spaces between adjacent teeth for measuring a magnetic flux density.The control unit includes a calculation unit for obtaining a rotation angle and / or an eccentricity of the rotor based on signals from the plurality of magnetic sensors, and a magnetic sensor signal used by the calculation unit is a signal from the magnetic sensor provided in the slot in which the windings on both sides have the same phase and opposite directions of energization. Effects of the invention

[0008] The present disclosure can achieve the effect of providing a motor system capable of reducing the detection error of information about a detection target, which is the rotation angle and / or the eccentricity. Short description of the drawings Fig. 1 is a diagram illustrating a configuration of an engine system according to the first embodiment. Fig. 2 is a diagram illustrating a cross-sectional configuration of the engine according to the first embodiment. Fig. 3 is a partially enlarged view of Fig. 2. Fig. 4 is a diagram illustrating a configuration of an XZ cross section of the motor according to the first embodiment. Fig. 5 is a diagram illustrating a correlation between the positional deviation amount in the direction of the rotation axis between the rotor and the magnetic sensor and the magnitude of a signal detected by the magnetic sensor. Fig. Figure 6 is a graph illustrating a relationship between the inclination of the rotor and the magnitude of the detection signal of the magnetic sensor. Fig. Figure 7 is a diagram illustrating the relationship between the position of the magnetic sensor and the magnetic flux density in the radial direction. Fig. 8 is a diagram illustrating a cross-sectional configuration of an engine according to a modification of the first embodiment. Fig. 9 is a diagram illustrating a cross-sectional configuration of a motor according to the second embodiment. Fig. 10 is a diagram illustrating a cross-sectional configuration of an engine according to a modification of the second embodiment. Fig. 11 is a diagram illustrating a cross-sectional configuration of an engine according to the third embodiment. Fig. 12 is a diagram illustrating a cross-sectional configuration of an engine according to a modification of the third embodiment. Fig. 13 is a diagram illustrating a configuration of a control unit according to the fourth embodiment. Fig. 14 is a diagram illustrating an example of a relationship between the amount of current applied to the winding and the signal of the magnetic sensor. Fig. 15 is a diagram explaining the Fig. 13 illustrated correction unit. Description of embodiments

[0009] Hereinafter, an engine system and an engine according to embodiments of the present disclosure will be described in more detail with reference to the drawings. First embodiment.

[0010] Fig. 1 is a diagram illustrating a configuration of a motor system 100 according to the first embodiment. The motor system 100 includes a motor 1 and a control unit 2. The motor 1 is a device that converts electrical energy into mechanical energy. Specifically, the motor 1 outputs a rotational motion using a force due to an interaction between a magnetic field and a current. The control unit 2 controls the motor 1.

[0011] A magnetic sensor 17 for measuring a magnetic flux density is attached to the motor 1. The magnetic sensor 17 outputs a signal indicating the measured magnetic flux density to the control unit 2. The control unit 2 includes a calculation unit 21 that calculates the rotation angle and eccentricity of the motor 1 based on a signal from the magnetic sensor 17. The control unit 2 can control the motor 1 based on the detected rotation angle and eccentricity. Although the magnetic sensor 17 in Fig. 1 is represented by a block, the motor 1 includes a plurality of magnetic sensors 17. Although the control unit 2 detects the rotation angle and the eccentricity here, the control unit 2 detects the rotation angle and / or the eccentricity. That is, the control unit 2 can detect only the rotation angle, only the eccentricity, or both the rotation angle and the eccentricity.

[0012] Fig. Figure 2 is a diagram illustrating a cross-sectional configuration of the motor 1 according to the first embodiment. Given that the direction of the rotation axis of the motor 1 is the Z-axis direction, Fig. 2 shows an XY cross section. The motor 1 includes a rotor 10, a permanent magnet 11 arranged in the rotor 10, and a stator 12. The rotor 10 has a columnar shape whose longitudinal direction is the Z-axis direction, and the permanent magnet 11 is arranged on the outer circumference. The permanent magnet 11 of the rotor 10 is an example of a magnetic flux generator that generates a magnetic flux. The magnetic flux generator can be not only the permanent magnet 11 but also a field winding. Here, the magnetic flux generated by the permanent magnet 11 contributes to the generation of the torque of the motor 1 and is also used to detect the rotation angle and eccentricity. Therefore, it is possible to detect the rotation angle and eccentricity while reducing the increase in the volume and mass of the entire motor 1.The stator 12 includes a cylindrical back yoke 13 arranged facing the rotor 10 with a gap from the rotor 10, and a plurality of teeth 14 projecting from the back yoke 13 toward the rotor 10. The plurality of teeth 14 are arranged at intervals in the circumferential direction. A space between adjacent teeth 14 is referred to as a groove 15.

[0013] The number of teeth 14 and slots 15 of the stator 12 is 12 and the number of poles of the permanent magnet 11 of the rotor 10 is 10. Therefore, the motor 1 has 10 poles and 12 slots.

[0014] The motor 1 also includes a winding 16 wound around each of the plurality of teeth 14. The winding 16 of phase U is designated 16U or 16U (overbar). U (overbar) represents U with an overbar above the U. Hereinafter, in this specification, reference symbols with an overbar above it may similarly be represented by adding (overbar) after the reference symbol. Here, the winding 16U (overbar) means that the direction of current supply is opposite to that of the winding 16U. Here, the winding 16U is wound such that an outward magnetic flux is generated in the tooth 14 around which the winding 16U is wound when a positive current is applied, and the winding 16U (overbar) is wound such that an inward magnetic flux is generated in the tooth 14 around which the winding 16U (overbar) is wound when a positive current is applied.

[0015] The motor 1 includes a winding 16U, a winding 16U (overline), a winding 16V (overline), a winding 16V, a winding 16W, a winding 16W (overline), a winding 16U (overline), a winding 16U, a winding 16V, a winding 16V (overline), a winding 16W (overline) and a winding 16W in a counterclockwise order starting from the 3:00 position on the illustration. Fig. 2, so that the motor 1 has a shape with 12 slots and generates a 10-pole magnetic field.

[0016] The magnetic sensor 17 is a sensor such as a Hall element and can convert a magnetic field or magnetic flux density into a voltage and measure the voltage. The motor 1 contains six magnetic sensors 17.

[0017] In the case where the plurality of magnetic sensors 17 are distinguished, a hyphen and a number are added after the reference numeral 17, and the magnetic sensors are referred to as magnetic sensors 17-1 to 17-6. The magnetic sensor 17 may be a digital output system in which the output changes with a threshold value as a limit, or may be an analog output system in which the output changes linearly proportional to the value of the magnetic flux density. In the digital output system, the range of the rotation angle and eccentricity may be known, and in the analog output system, the values ​​of the rotation angle and eccentricity may be directly known. Furthermore, in the analog output system, the influence of the magnetic flux due to the current supply to the winding 16 directly appears in the signal of the magnetic sensor 17, which is more likely to cause a problem than in the digital output system.In the following description, it is assumed that the magnetic sensor 17 is the analog output system. In air, the magnetic field and the magnetic flux density are proportional to each other. In this document, the detection target of the magnetic sensor 17 is primarily described as the magnetic flux density, but it can also be the magnetic field.

[0018] The magnetic sensor 17 is provided in the slot 15, in which the phases of the windings 16 wound around the teeth 14 on both sides are the same and the energization directions are opposite to each other. In other words, the magnetic sensor 17 is provided between the windings 16, which have the same phase and opposite energization directions. Specifically, the magnetic sensor 17-1 is provided between the winding 16U and the winding 16U (overbar). The magnetic sensor 17-2 is provided between the winding 16V and the winding 16V (overbar). The magnetic sensor 17-3 is provided between the winding 16W and the winding 16W (overbar). The magnetic sensor 17-4 is provided between the winding 16U and the winding 16U (overbar). The magnetic sensor 17-5 is provided between the winding 16V and the winding 16V (overline).The magnetic sensor 17-6 is provided between the winding 16W and the winding 16W (overline).

[0019] Although six magnetic sensors 17-1 to 17-6 in Fig. 2, the number of magnetic sensors 17 is not specifically limited as long as the motor 1 includes a plurality of magnetic sensors. To calculate the angle using the magnetic sensor 17, it is only necessary to detect waveforms of magnetic flux densities on at least two sinusoidal waves having different phases with the rotation of the rotor 10. Therefore, at least two magnetic sensors 17 are required.

[0020] Given that the angle of the rotor 10, that is, the rotation angle, is θ, if information about the waveform X=cosθ and the waveform Y=sinθ can be calculated from the magnetic sensor 17, the rotation angle θ can be calculated using the following formula (1). Here, tan -1Arctangent. Formula 1: θ=tan−1YX

[0021] The cosθ and sinθ waveforms can be obtained directly from two magnetic sensors 17 arranged at positions electrically different by 90° in phase. In addition, the cosθ and sinθ waveforms can also be calculated by performing four arithmetic operations including the three-to-two phase conversion described later on signals from three or more magnetic sensors 17. Moreover, even in a case where only two magnetic sensors 17 are arranged and the electrical phase difference is not 90°, the cosθ and sinθ waveforms can be obtained by performing four arithmetic operations on two signals. For example, assume that a waveform X=cosθ and a waveform Y'=cos(θ-60°) are given. In this case, the waveform Y=sinθ can be obtained by calculating the following formula (2). Formula 2: Y=23Y'−13X

[0022] The windings 16 of the same phase can all be connected in series or partially in parallel. When all windings 16 of the same phase are connected in series, the values ​​of the currents flowing through all windings 16 of the same phase are equal. Even if the windings 16 of the same phase are partially connected in parallel, if the current flowing in the parallel connection is small, the value of the current flowing through each winding 16 can be considered equal. The three phases of phase U, phase V, and phase W can be connected by a Y connection or a Δ connection.

[0023] Fig. 3 is a partially enlarged view of Fig. 2. With reference to Fig. 3, a description will be given of a principle for canceling a magnetic flux density generated by energizing the winding 16 when the magnetic sensor 17 is provided in the slot 15 in which the phases of the windings 16 wound around the teeth 14 on both sides are the same and the directions of energization are opposite to each other. Fig. 3 illustrates a state where a positive current flows through the winding 16U. Due to the right-hand rule, magnetic flux densities are generated around the winding 16U and the winding 16U (overbar). The magnitude of the generated magnetic flux density is generally proportional to the current and inversely proportional to the distance from the winding 16. Therefore, as the current flowing through the winding 16 increases and as the magnetic sensor 17 is closer to the winding 16, the influence of the magnetic flux density generated by the winding 16 on the magnetic sensor 17 increases.

[0024] However, the magnetic sensor 17 is provided in the slot 15, in which the phases of the windings 16 wound around the teeth 14 on both sides are the same and the directions of current flow are opposite to each other. This means that the windings 16 located on both sides of the magnetic sensor 17 have the same phase and opposite directions of current flow. Therefore, the magnetic flux density generated at the location where the magnetic sensor 17 is arranged is the sum of the magnetic flux densities generated by the two windings 16 arranged on both sides of the magnetic sensor 17. Specifically, the Fig. 3 is influenced by a magnetic flux 18U generated by the winding 16U and a magnetic flux 18U (overbar) generated by the winding 16U (overbar). At this time, when the magnetic sensor 17-1 is located exactly at the intermediate position between the winding 16U and the winding 16U (overbar), the magnetic flux 18U and the magnetic flux 18U (overbar) have the same magnitude and opposite directions in the radial direction R. Therefore, the influence of the winding 16U on the magnetic sensor 17-1 is canceled by the influence of the winding 16U (overbar) on the magnetic sensor 17-1. Although the magnetic sensor 17-1 has been described here, the same applies to the other magnetic sensors 17-2 to 17-6.At the position where the magnetic sensors 17-1 to 17-6 are arranged, the magnetic flux density does not change even if the energization amount of the winding 16 increases or decreases, and only the magnetic flux from the permanent magnet 11 of the rotor 10 appears. Therefore, the magnetic sensor 17 can only detect the magnetic flux from the permanent magnet 11 of the rotor 10.

[0025] In the above description, the motor 1 is a radial flux motor in which the rotor 10 and the stator 12 face each other in the radial direction. An axial flux motor in which the rotor 10 and the stator 12 face each other in the direction of the rotation axis has a similar effect. In the case of the axial flux motor, the direction of the magnetic flux from the rotor 10 is mainly the direction of the rotation axis. In the stator 12, the direction of the magnetic flux from the windings 16 on both sides of the magnetic sensor 17 is also mainly the direction of the rotation axis. Furthermore, when the magnetic sensor 17 in the axial flux motor is arranged between two windings 16 that have the same phase and opposite energization directions, the magnetic fluxes from the windings 16 on both sides have the same magnitude and opposite directions and cancel each other out.Therefore, the magnetic sensor 17 can only detect the magnetic flux from the permanent magnet 11 arranged in the rotor 10.

[0026] As described above, by disposing the magnetic sensor 17 in the slot 15 in which the phases of the windings 16 wound around the teeth 14 on both sides are the same and the directions of energization are opposite to each other, it is not necessary to consider the influence of the windings 16 on the magnetic sensor 17. Therefore, it is not necessary to increase the distance between the magnetic sensor 17 and the winding 16. Therefore, it is possible to dispose the magnetic sensor 17 close to the winding 16. Since the limited space of the slot 15 can be allocated to the winding 16 instead of the space for converting the distance between the winding 16 and the magnetic sensor 17, the resistance of the winding 16 can be reduced and the copper loss during operation can be reduced.To significantly reduce the influence of the winding, a permanent magnet for detecting the rotation angle and eccentricity can be prepared at a position physically distant from the motor 1 and the winding 16, and a magnetic flux of the permanent magnet for detecting can be detected. However, such a measure is not necessary. As a result, the size and mass of the entire motor 1 can be reduced while maintaining the same power and loss.

[0027] Fig. 4 is a diagram illustrating a configuration of an XZ cross section of the motor 1 according to the first embodiment. Here, the XZ cross section is a cross section including the rotation axis and the radial direction R. Conventionally, in order to reduce the influence of the magnetic flux from the winding 16, a method of shifting the position of the magnetic sensor 17 in the direction of the rotation axis, that is, the Z-axis direction, has been performed. However, when the position of the magnetic sensor 17 is shifted in the direction of the rotation axis, the magnitude of the magnetic flux 19 from the permanent magnet 11 of the rotor 10 is also reduced, and consequently, a signal-to-noise ratio (SNR) is less likely to decrease.The magnetic sensor 17 of the motor 1 may be arranged at a position away from the winding 16 in the direction of the rotation axis, but may be arranged at the center position of the rotor 10 in the direction of the rotation axis, as shown in FIG. Fig. 4 as Δz≈0. This is because, as described above, by disposing the magnetic sensor 17 in the slot 15 where the phases of the windings 16 wound around the teeth 14 on both sides are the same and the energization directions are opposite to each other, the influence of the windings 16 on both sides is canceled at any position in the rotation axis direction. Here, Δz represents a positional deviation amount from the center position of the rotor 10 in the rotation axis direction of each magnetic sensor 17. Fig. 4 illustrates the magnetic sensor 17 with Δz≈0, the magnetic sensor 17 with Δz<0 and the magnetic sensor 17 with Δz>0.

[0028] When the rotor 10 is suspended in the air due to magnetic levitation, an assembly error occurs, or vibration occurs in the rotor 10 or the stator 12, the relative position of the rotor 10 with respect to the magnetic sensor 17 may deviate in the direction of the rotation axis or the tilt direction. At this time, at the position shifted from the permanent magnet 11 of the rotor 10 in the axial direction, the magnitude of the signal detected by the magnetic sensor 17 may vary greatly due to the displacement of the rotor 10, the shift in the location of the magnetic sensor 17, and the like. When the magnetic sensor 17 is arranged at a position shifted from the rotor 10 in the axial direction, as the distance between the rotor 10 and the magnetic sensor 17 increases, the magnitude of the signal from the magnetic sensor 17 decreases, and as the distance between the rotor 10 and the magnetic sensor 17 decreases, the magnitude of the signal from the magnetic sensor 17 increases.

[0029] Fig. Fig. 5 is a graph illustrating a correlation between the position deviation amount Δz in the direction of the rotation axis between the rotor 10 and the magnetic sensor 17 and the magnitude of a signal detected by the magnetic sensor 17. The horizontal axis in Fig. 5 represents the position deviation amount Δz in the direction of the rotation axis between the rotor 10 and the magnetic sensor 17 and the vertical axis in Fig. Figure 5 illustrates the magnitude B of the detection signal of the magnetic sensor 17. The magnitude B of the detection signal of the magnetic sensor 17 has a maximum value near Δz=0, and a change in the magnitude B of the detection signal is small near Δz≈0. Conversely, as the absolute value of the position deviation amount Δz increases, a slight change in the value of Δz results in a large change in the magnitude B of the detection signal of the magnetic sensor 17.

[0030] Fig. 6 is a graph illustrating a relationship between the inclination Δθ of the rotor 10 and the magnitude B of the detection signal of the magnetic sensor 17. In a case where the magnetic sensor 17 is arranged at a position where Δz≈0, even if the rotor 10 is inclined and the value of Δθ changes, the distance between the magnetic sensor 17 and the permanent magnet 11 hardly changes, and thus the magnitude B of the detection signal of the magnetic sensor 17 does not change. On the other hand, in a case where the magnetic sensor 17 is arranged at a position where Δz>0, if the rotor 10 is inclined and the absolute value of Δθ changes, the distance between the magnetic sensor 17 and the permanent magnet 11 changes.

[0031] In the motor 1, the magnetic sensor 17 is arranged between the windings 16, which have the same phase and opposite energization directions. When such a condition is met, by arranging the magnetic sensor 17 near Δz≈0, which is the center position of the rotor 10, in the direction of the rotation axis of the motor 1, it is possible to reduce the influence of the magnetic flux from the winding 16 while increasing the magnitude of the magnetic flux from the permanent magnet 11 of the rotor 10. As a result, the SNR at each stage can be improved compared to the conventional technique in which the magnetic sensor 17 is arranged at a position shifted from the center position of the rotor 10 in the direction of the rotation axis.In addition, when the magnetic sensor 17 is arranged near Δz≈0, which is the central portion in the direction of the rotation axis of the motor 1, even if the rotor 10 and the magnetic sensor 17 are relatively shifted in the axial direction or the tilt direction, the magnitude B of the detection signal of the magnetic sensor 17 hardly changes. Therefore, the magnetic sensor 17 can robustly detect the magnetic flux against positional displacement, vibration, and the like of the magnetic sensor 17 and the rotor 10. In addition, by disposing a plurality of magnetic sensors 17 at the position of Δz>0 and the position of Δz<0, it is possible to detect the position in the axial direction and the position in the tilt direction of the rotor 10 while reducing the influence of the magnetic flux from the winding 16 due to energization.

[0032] Fig. 7 is a diagram illustrating the relationship between the position of the magnetic sensor 17 and the magnetic flux density in the radial direction R. In Fig. 7, the magnetic flux density in the radial direction R when the magnetic sensor 17 is arranged near the rotor 10, that is, near the gap between the rotor 10 and the stator 12, is indicated by a dashed line. In Fig. In Figure 7, the magnetic flux density in the radial direction R when the magnetic sensor 17 is located away from the gap and within the groove 15 is indicated by a solid line. The position away from the gap indicates the positive side of the radial direction R in the inner rotor type in which the rotor 10 is located within the stator 12, as shown in Fig. 2, and denotes the negative radial direction R in the outer rotor type in which the rotor 10 is located outside the stator 12. The closer the magnetic sensor 17 is to the gap, the more the magnetic flux is absorbed by the permanent magnet 11 and the larger the acquired signal becomes. However, the magnetic flux from the permanent magnet 11 includes not only a fundamental wave component but also many harmonic components. Therefore, in a case where the magnetic sensor 17 is arranged at a position close to the gap and the signal from the magnetic sensor 17 contains many harmonic components, the signal detected by the magnetic sensor 17 is not an ideal sine wave, as shown by the dashed line in Fig. 7, and the angular error increases.

[0033] When the magnetic sensor 17 is positioned away from the gap in the direction inside the slot 15, that is, closer to the return yoke 13 than to the tip of the tooth 14, the fundamental wave component decreases, but the spatial harmonic component causing the angular error decreases significantly. Therefore, the signal detected by the magnetic sensor 17 approaches a sine wave, and the angular error due to the spatial harmonics from the permanent magnet 11 is reduced. Here, locating the magnetic sensor 17 inside the slot 15 causes the magnetic sensor 17 to be closer to the winding 16 of the stator 12 and is susceptible to the influence of the magnetic flux from the winding 16.However, as described above, when the magnetic sensor 17 is arranged between the windings 16 having the same phase and opposite energization directions, the influence of the magnetic flux from one winding 16 can be canceled by the influence of the magnetic flux from the other winding 16, so that an increase in the influence of the magnetic flux from the winding 16 can be reduced. Therefore, by disposing the magnetic sensor 17 between the windings 16 having the same phase and opposite energization directions within the slot 15, it is possible to achieve both the reduction of the influence of the spatial harmonics from the permanent magnet 11 and the reduction of the influence of the magnetic flux from the winding 16.

[0034] Next, signals detected by the respective magnetic sensors 17 when the magnetic sensors 17 are as shown in Fig. 2 is illustrated with 10 poles and 12 slots arranged, and a post-processing method performed by the calculation unit 21 of the control unit 2 using these signals is described using formulas.

[0035] The number of pole pairs is five. The value of the number of pole pairs "5" is greater than "4," which corresponds to 1 / 3 of the number of slots "12," and less than "8," which corresponds to 2 / 3 of the number of slots "12."

[0036] Here, signals from the six magnetic sensors 17-1 to 17-6 are designated S1 to S6, respectively. That is, the signal from the nth magnetic sensor 17-n is S n . S n is expressed by the formula (3) below. Here, B0 is the amplitude of the fundamental wave of the magnetic flux from the permanent magnet 11 of the rotor 10 when it is not eccentric in the radial direction R, p is the number of pole pairs of the permanent magnet 11, θ is the angle of the rotor 10, and αn is the angle at which the magnetic sensor 17 is arranged. In addition, b is a coefficient representing the ratio of the third-order harmonic component to the fundamental wave of the permanent magnet 11, r is the magnitude of the eccentricity of the rotor 10, φ is the direction of the eccentricity of the rotor 10 with the direction of the x-axis as a reference of 0 degrees, and R n and L n magnetic flux densities generated by energizing the windings 16 located on both sides of the n-th magnetic sensor 17-n. Formula 3: Sn=B0[cos p(θ−αn)+b cos 3p(θ−αn)][1+r cos(φ−αn)]+Rn+Ln

[0037] Given that the displacement amount of the rotor 10 in the X direction is x and the displacement amount of the rotor 10 in the Y direction is y, relationships of the following formulas (4) and (5) are established between x and y and r and φ. Formula 4: x=r cos φ Formula 5: y=r sin φ

[0038] In Fig. 2 werden, behand die 3:00-Position auf der Darstellung 0° begült, α1=15°, α2=α1+60°, α3=α1+120°, α4=α1+180°, α5=α1+240° und α6=α1+300° set. Additional p=5. Unter Verwendung der Beziehung von α2=α5-180° und α6=α3+180°, werden S1 bis S6 correspondingly durch die nachstehenden Formeln (6) bis (11) ausgerückt. Formula 6: S1=B0[cos p(θ−α1)+b cos 3p(θ−α1)][1+r cos(φ−α1)]+R1+L1 Formula 7: S2=−B0[cos p(θ−α5)+b cos 3p(θ−α5)][1−r cos(φ−α5)]+R2+L2 Formula 8: S3=B0[cos p(θ−α3)+b cos 3p(θ−α3)][1+r cos(φ−α3)]+R3+L3 Formula 9: S4=−B0[cos p(θ−α1)+b cos 3p(θ−α1)][1−r cos(φ−α1)]+R4+L4 Formula 10: S5=B0[cos p(θ−α5)+b cos 3p(θ−α5)][1+r cos(φ−α5)]+R5+L5 Formula 11: S6=−B0[cos p(θ−α3)+b cos 3p(θ−α3)][1−r cos(φ−α3)]+R6+L6

[0039] Here, the calculation unit 21 of the control unit 2 sets two magnetic sensors 17 as a pair and calculates a difference between signals of the pair of magnetic sensors 17. Concretely, the calculation unit 21 sets the magnetic sensor 17-1 and the magnetic sensor 17-4 as a pair of sensors, the magnetic sensor 17-2 and the magnetic sensor 17-5 as a pair of sensors, and the magnetic sensor 17-3 and the magnetic sensor 17-6 as a pair of sensors.

[0040] S1-S4 is expressed by the following formula (12), S5-S2 is expressed by the following formula (13), and S3-S6 is expressed by the following formula (14). Formula 12: S1−S4=2B0[cos p(θ−α1)+b cos 3p(θ−α1)]+R1+L1−R4−L4 Formula 13: S5−S2=2B0[cos p(θ−α5)+b cos 3p(θ−α5)]−R2−L2+R5+L5=2B0[cos[p(θ−α1)−120°]+b cos 3p(θ−α1)]−R2−L2+R5+L5 Formula 14: S3−S6=2B0[cos p(θ−α3)+b cos 3p(θ−α3)]+R3+L3−R6−L6=2B0[cos[p(θ−α1)−240°]+b cos 3p(θ−α1)]+R3+L3−R6−L6

[0041] Further, the calculation unit 21 performs a three-to-two-phase conversion on the calculated “S1-S4”, “S5-S2” and “S3-S6” as expressed by formula (15). Formula 15: 23⌊1−12−12032−32⌋[S1−S4S5−S2S3−S6]=23[3B0 cos p(θ−α1)+R1+L1−R4−L4−−R2−L2+R5+L5+R3+L3−R6−L62 3B0 sin p(θ−α1)+32(−R2−L2+R5+L5−R3−L3+R6+L6)]

[0042] In formula (15), even if the value of the coefficient b, which represents the ratio of the third-order harmonic component to the fundamental wave of the permanent magnet 11, is not zero, b is not included in the signal after the three-to-two-phase conversion. Therefore, the influence of the third-order harmonic component can be removed by using the difference between the signals of the pair of magnetic sensors 17 and performing a three-to-two-phase conversion.

[0043] In addition, a condition that the windings 16 located on both sides of the magnetic sensor 17 have the same phase and opposite directions of current flow is considered. For example, the winding 16U of phase U and the winding 16U (overline) of layer U (overline) are located on both sides of the magnetic sensor 17. Here, given that the current flowing through the winding 16U is represented by i uand the proportional coefficient is represented by k, R1=ki u and L1=-ki u Therefore, R1+L1=0. Since all magnetic sensors 17 are provided in slots in which the windings 16 wound on both sides around the teeth 14 have the same phase and opposite directions of current flow, R n +L n =0. At this time, the following formula (16) applies. Formula 16: 23⌊1−12−12032−32⌋[S1−S4S5−S2S3−S6]=23[3B0 cos p(θ−α1)3B0 sin p(θ−α1)]

[0044] Therefore, the calculation unit 21 substitutes the detected signal of the magnetic sensor 17 into formula (16) to calculate the arctangent, thereby obtaining p(θ-α1). Here, if p and α1 are known, the calculation unit 21 can calculate θ.

[0045] That is, the influence of the spatial harmonics of a multiple of three from the permanent magnet 11 and the magnetic flux from the winding 16 is removed from the angle information output from the calculation unit 21.

[0046] Next, a method for calculating the eccentricity will be described. Two magnetic sensors 17 are set as a pair, and the sum is calculated. Specifically, the calculation unit 21 sets the magnetic sensor 17-1 and the magnetic sensor 17-4 as a pair of sensors, the magnetic sensor 17-2 and the magnetic sensor 17-5 as a pair of sensors, and the magnetic sensor 17-3 and the magnetic sensor 17-6 as a pair of sensors.

[0047] S1+S4 is expressed by the following formula (17), S2+S5 is expressed by the following formula (18), and S3+S6 is expressed by the following formula (19). Formula 17: S1+S4=2B0[cos p(θ−α1)+b cos 3p(θ−α1)]r cos(φ−α1) +R1+L1+R4+L4 Formula 18: S2+S5=2B0[cos p(θ−α5)+b cos 3p(θ−α5)]r cos(φ−α5)+R2+L2+R5+L5=2B0[cos[p(θ−α1)−120°]+ b cos 3p(θ−α1)]r cos(φ−α1+120°)+R2+L2+R5+L5 Formula 19: S3+S6=2B0[cos p(θ−α3)+b cos 3p(θ−α3)]r cos(φ−α3)+R3+L3+R6+L6=2B0[cos[p(θ−α1)−240°]+ b cos 3p(θ−α1)]r cos(φ−α1−120°)+R3+L3+R6+L6

[0048] Furthermore, the calculation unit 21 performs a three-to-two-phase conversion to the calculated “S l +S4”, “S2+S5” and “S3+S6” as expressed by formula (20). Formula 20: 23⌊1−12−12032−32⌋[S1+S4S2+S5S3+S6]=23[3B0b cos 3p(θ−α1)r cos(φ−α1)+R1+L1+R4+L4−R2+L2+R5+L5+R3+L3+R6+L62 −3B0b cos 3p(θ−α1)r sin p(φ−α1)+32(R2+L2+R5+L5−R3−L3−R6−L6)]+23[2B0r(cos p(θ−α1)cos(φ−α1)+sin p(θ−α1)sin(φ−α1))342B0r(cos p(θ−α1)sin(φ−α1)−sin p(θ−α1)cos(φ−α1))34]=23[3B0b cos 3p(θ−α1)r cos(φ−α1)+R1+L1+R4+L4−R2+L2+R5+L5+R3+L3+R6+L62 −3B0b cos 3p(θ−α1)r sin p(φ−α1)+32(R2+L2+R5+L5−R3−L3−R6−L6)]+23[32B0r cos[p(θ−α1)−(φ−α1)]−32B0r cos[p(θ−α1)−(φ−α1)]]

[0049] As shown in formula (20), the influence of the third-order harmonic component of the permanent magnet 11 on the eccentricity remains even after the three-to-two-phase conversion. However, if the magnetic sensor 17 is arranged within the groove 15 as described above, the contribution of the third-order harmonic wave can be greatly reduced. Given that R n +L n=0 and the third order harmonic is relatively negligible, the formula (20) can be approximated as formula (21). Formula 21: 23⌊1−12−12032−32⌋[S1+S4S2+S5S3+S6]≅23[32B0r cos [p(θ−α1)−(φ−α1)]−323B0r sin [p(θ−α1)−(φ−α1)]] =32[B0r cos [(φ−α1)−p(θ−α1)]B0r sin [(φ−α1)−p(θ−α1)]]

[0050] Since B0cosp (θ-α1) and B0sinp (θ-α1) have been calculated, a function that does not include θ but includes r and φ can be obtained by using them as a rotation matrix, as given in the following formula (22). Formula 22: 1(B0 cos p(θ−α1))2+(B0 sin p(θ−α1))2[B0 cos p(θ−α1) −B0 sin p(θ−α1)B0 sin p(θ−α1)B0 cos p(θ−α1)]⋅[B0r cos[(φ−α1)−p(θ−α1)]B0r sin[(φ−α1)−p(θ−α1)]]=[r cos(φ−α1)r sin(φ−α1)]

[0051] This is equivalent to the position information in the radial direction of the rotor 10. The calculation unit 21 can calculate the eccentricity as described above.

[0052] Although the case where the number of pole pairs of the permanent magnet 11 is five, an odd number, was described above, the rotation angle and eccentricity can be obtained equally even when the number of pole pairs is an even number. However, when the number of pole pairs is an even number, the sum is calculated instead of the difference between the signals of the pair of magnetic sensors 17 when calculating the angle.

[0053] Although the motor 1 is described above as having 10 poles and 12 slots, the number of slots only needs to be a multiple of six, that is, twelve or more, and the number p of pole pairs of the permanent magnet 11 and the number of pole pairs generated by the winding 16 only need to be greater than 1 / 3 times the number of slots and less than 2 / 3 times the number of slots. By setting the relationship between the number of slots, the number p of pole pairs of the permanent magnet 11, and the number of pole bodies generated by the winding 16 as described above, it is possible to provide the slots 15 in which the windings 16 wound around the teeth 14 on both sides have the same phase and opposite directions of energization.Therefore, the signal of the magnetic sensor 17 used when the calculation unit 21 obtains the rotation angle and / or the eccentricity of the motor 1 may be a signal of the magnetic sensor 17 provided in the groove 15 in which the windings 16 wound on both sides around the teeth 14 have the same phase and opposite directions of energization.

[0054] Fig. 8 is a diagram illustrating a cross-sectional configuration of an engine 1-1 according to a modification of the first embodiment. Fig. Figure 8 illustrates the motor 1-1, which has eight poles and nine slots. It mainly shows the differences to the motor shown in Fig. 2. The motor 1-1 differs from the motor 1 in that the motor 1 has 10 poles and 12 slots, whereas the motor 1-1 has 8 poles and 9 slots. That is, the motor 1-1 includes the rotor 10 and the stator 12. The stator 12 of the motor 1-1 has nine teeth 14, and the winding 16 is wound around each of the teeth 14. Here, the windings 16 of the motor 1-1 are shown in order starting from the 3:00 position on the illustration. Fig. 8 counterclockwise, a 16U winding, a 16U winding (overstroke), a 16V winding (overstroke), a 16V winding, a 16V winding (overstroke), a 16W winding (overstroke), a 16W winding, a 16W winding (overstroke), and a 16U winding (overstroke). Here, the motor 1-1 includes magnetic sensors 17 arranged at three locations: the slot 15 provided between the 16U winding and the 16U winding (overstroke); the slot 15 provided between the 16V winding and the 16V winding (overstroke); and the slot 15 provided between the 16W winding and the 16W winding (overstroke).

[0055] Also in the motor 1-1, the magnetic sensor 17 is provided in the slot 15, where the windings 16 wound around the teeth 14 on both sides have the same phase and opposite directions of current flow. The number p of pole pairs of the permanent magnet 11 is four, and the number p of pole pairs is greater than three, which is 1 / 3 times the number of slots (nine), and less than six, which is 2 / 3 times the number of slots (nine).

[0056] Although the example with eight poles and nine slots is shown here, the number of slots only needs to be a multiple of three, that is, nine or more, and the number p of pole pairs of the permanent magnet 11 and the number of pole pairs generated by the winding 16 only need to be greater than 1 / 3 times the number of slots and less than 2 / 3 times the number of slots. By setting the relationship between the number of slots, the number p of pole pairs of the permanent magnet 11, and the number of pole pairs generated by the winding 16 as described above, it is possible to provide the slots 15 in which the windings 16 wound around the teeth 14 on both sides have the same phase and opposite directions of energization.

[0057] Although the Fig. 2 and Fig. 8 illustrates the radial flux motor in which the stator 12 is disposed outside the rotor 10 and the stator 12 and the rotor 10 face each other with a gap surface in the radial direction, the above-described effect can be obtained even in the case of an outer rotor type in which the stator 12 is disposed inside the rotor 10. Furthermore, even in an axial flux motor in which the stator 12 and the rotor 10 face each other with a gap surface in the axial direction, a similar effect can be obtained.

[0058] The connection method of the windings 16 of the U-phase, the V-phase, and the W-phase may be a Y connection or a Δ connection. Moreover, even when the windings 16 of the same phase are connected in series or parallel, substantially the same amount of current flows in the same phase, so a similar effect can be obtained. Although the motor 1 and the motor 1-1 in the first embodiment were described using the three-phase windings 16, even in a case where two-phase windings or windings of four or more phases are used, if the magnetic sensor 17 is arranged between windings having the same phase and opposite directions of energization to each other, an effect similar to that of the first embodiment can be obtained.

[0059] Furthermore, even in a case where a plurality of single-phase inverters and windings are used, a similar effect can be obtained by disposing a magnetic sensor between the single-phase windings.

[0060] As described above, according to the first embodiment, the motor system 100 is provided, which includes the motor 1 and the control unit 2 that controls the motor 1. The motor 1 includes the rotor 10 in which the permanent magnet 11, which is a magnetic flux generator that generates a magnetic flux, is arranged, and the stator 12 arranged facing the rotor 10. The stator 12 includes the return yoke 13 arranged facing the rotor 10 and the plurality of teeth 14 that protrude from the return yoke 13 toward the rotor 10 and are arranged adjacently at intervals in the rotation direction of the rotor 10. In addition, the motor 1 includes the winding 16 wound around the stator 12 and the plurality of magnetic sensors 17 provided in the slots 15, which are spaces between adjacent teeth 14, for measuring a magnetic flux density.The control unit 2 includes the calculation unit 21, which obtains the rotation angle and / or eccentricity of the rotor 10 based on signals from the plurality of magnetic sensors 17. The signal of the magnetic sensor 17 used by the calculation unit 21 is a signal from the magnetic sensor 17 provided in the slot 15 in which the windings 16 on both sides have the same phase and opposite energization directions. By providing the magnetic sensor 17 in the slot 15 in which the windings 16 on both sides have the same phase and opposite energization directions, the signal from the magnetic sensor 17 is the one in which the influence of one of the windings 16 on both sides is canceled by the influence of the other winding 16, even when the winding 16 is energized.Accordingly, it is possible to reduce the detection error of information about a detection target, which is the rotation angle and / or eccentricity.

[0061] Furthermore, the magnetic sensor 17 is arranged within the groove 15, i.e., between the adjacent teeth 14, and in the radial direction R around the rotation axis of the motor 1, closer to the return yoke 13 than to the tip of the teeth 14. As a result, the spatial harmonic component of the signal from the magnetic sensor 17 can be significantly reduced, and the detection error of information about a detection target, which is the rotation angle and / or eccentricity, can be reduced. In the axial motor, "closer to the return yoke 13" refers to the axial direction, i.e., the Z direction.

[0062] Additionally, the motor 1 includes three pairs of magnetic sensors 17, each including a first sensor and a second sensor, and the calculation unit 21 calculates the sum or difference between a signal of the first sensor and a signal of the second sensor in each pair. As a result, the influence of the space harmonic component of a multiple of three from the permanent magnet 11 and the influence of the magnetic flux generated by energizing the winding 16 are removed from the rotation angle and eccentricity output from the calculation unit 21. Accordingly, it is possible to reduce the detection error of information about a detection target, which is the rotation angle and / or eccentricity.

[0063] The number of slots 15 in the motor 1 is 12, which satisfies the condition of a multiple of six, that is, twelve or more. The motor 1 satisfies the condition that the number of pole pairs of the permanent magnet 11 as a magnetic flux generator and the number of pole pairs generated by the winding 16 is 5, which is greater than 4, that is, 1 / 3 times the number of slots 12, and less than 8, that is, 2 / 3 times the number of slots 12. By setting the number of slots and the number of pole pairs to satisfy such conditions, the magnetic sensor 17 can be arranged in the slots 15 in which the windings 16 wound around the teeth 14 on both sides have the same phase and opposite directions of energization. Accordingly, it is possible to reduce the detection error of information about a detection target, which is the rotation angle and / or eccentricity.

[0064] The motor 1-1 according to the modification of the first embodiment has eight poles and nine slots. In this case, the number of slots is "9," which satisfies the condition of a multiple of three, that is, nine or more. The condition is satisfied that the number of pole pairs of the permanent magnet 11 and the number of pole pairs generated by the winding 16 is "4," which is greater than "3," that is, 1 / 3 times the number of slots "9," and less than "6," that is, 2 / 3 times the number of slots "9." By setting the number of slots and the number of pole pairs to satisfy such conditions, the magnetic sensor 17 can be arranged in the slots 15 in which the windings 16 wound around the teeth 14 on both sides have the same phase and opposite directions of energization.Accordingly, it is possible to reduce the detection error of information about a detection target, which is the rotation angle and / or eccentricity. Second embodiment.

[0065] Fig. 9 is a diagram illustrating a cross-sectional configuration of a motor 1-2 according to the second embodiment. The motor 1-2 differs from that of the first embodiment in that it has 16 poles and 18 slots, and two types of windings are wound around each tooth 14. The configuration of the motor 1-2 is similar to that of the motor 1 except for the above points. The motor 1-2 includes the rotor 10 having the return yoke 13 and the teeth 14, the rotor 10 including the permanent magnet 11, and the magnetic sensor 17 provided in a space between adjacent teeth 14. Note that, as in the first embodiment, the signal of the magnetic sensor 17 is output to the calculation unit 21 of the control unit 2. The following mainly describes differences from the first embodiment.

[0066] The motor 1-2 has 18 teeth 14. A first winding 31 and a second winding 32 are wound around each tooth 14. In the example from Fig. In Figure 9, the first winding 31 and the second winding 32 are wound in an overlapping manner. Here, the first winding 31 is wound outside the second winding 32. The rotor 10 contains the 16-pole permanent magnet 11. The number of slots 15 of the stator 12 is 18.

[0067] The first winding 31 is wound around the 18 teeth 14 to generate a magnetic field of 16 poles. The first windings 31 of the motor 1-2 are arranged in a sequence starting from the 3:00 position on the diagram. Fig. 9 counterclockwise, a first winding 31U, a first winding 31U (overline), a first winding 31V (overline), a first winding 31V, a first winding 31V (overline), a first winding 31W (overline), a first winding 31W, a first winding 31W (overline), a first winding 31U (overline), a first winding 31U, a first winding 31U (overline), a first winding 31V (overline), a first winding 31V, a first winding 31V (overline), a first winding 31W (overline), a first winding 31W, a first winding 31W (overline) and a first winding 31U (overline). The second winding 32 of the motor 1-2 is wound around the 18 teeth 14 to generate a magnetic field of 14 poles. The second windings 32 are arranged in a sequence starting from the 3:00 position on the diagram. Fig. 9 counterclockwise a second winding 32V, a second winding 32V (overline), a second winding 32W (overline), a second winding 32U (overline), a second winding 32U, a second winding 32V, a second winding 32W, a second winding 32W (overline), a second winding 32U (overline), a second winding 32V (overline), a second winding 32V, a second winding 32W, a second winding 32U, a second winding 32U (overline), a second winding 32V (overline), a second winding 32V, a second winding 32W, a second winding 32U, a second winding 32U (overline), a second winding 32V (overline), a second winding 32W (overline), a second winding 32W and a second winding 32U.

[0068] The number of pole pairs generated by the second winding 32 is seven, and the number p of pole pairs of the permanent magnet 11 is eight. At this time, the condition that the number of pole pairs generated by the second winding 32 is one greater or one less than the number of pole pairs of the permanent magnet 11 is met. The number of pole pairs generated by the second winding 32 is greater than six, which is 1 / 3 times the number of slots, and less than 12, which is 2 / 3 times the number of slots.

[0069] The motor 1-2 includes the six magnetic sensors 17-1 to 17-6. The magnetic sensor 17-1 is arranged between the first winding 31U and the first winding 31U (oversweep). The magnetic sensor 17-2 is arranged between the first winding 31V and the first winding 31V (oversweep). The magnetic sensor 17-3 is arranged between the first winding 31W and the first winding 31W (oversweep). The magnetic sensor 17-4 is arranged between the first winding 31U and the first winding 31U (oversweep). The magnetic sensor 17-5 is arranged between the first winding 31V and the first winding 31V (oversweep). The magnetic sensor 17-6 is arranged between the first winding 31W and the first winding 31W (oversweep).

[0070] The magnetic sensor 17-1 is arranged between the second winding 32V and the second winding 32V (oversweep). The magnetic sensor 17-2 is arranged between the second winding 32U and the second winding 32U (oversweep). The magnetic sensor 17-3 is arranged between the second winding 32W and the second winding 32W (oversweep). The magnetic sensor 17-4 is arranged between the second winding 32U and the second winding 32U (oversweep). The magnetic sensor 17-5 is arranged between the second winding 32U and the second winding 32U (oversweep). The magnetic sensor 17-6 is arranged between the second winding 32W and the second winding 32W (oversweep).

[0071] In the motor 1-2, each of the magnetic sensors 17-1 to 17-6 is provided in the slot 15, in which the first windings 31 wound around the teeth 14 on both sides have the same phase and opposite energization directions, and the second windings 32 wound around the teeth 14 on both sides have the same phase and opposite energization directions. Therefore, similar to the first embodiment, it is possible to simultaneously reduce the influence of the magnetic flux of the first winding 31 and the influence of the magnetic flux of the second winding 32.

[0072] Fig. 10 is a diagram illustrating a cross-sectional configuration of a motor 1-3 according to a modification of the second embodiment. Here, differences from the motor 1-2 will be mainly described. The first winding 31 of the motor 1-3 is wound inside the second winding 32 in the radial direction R around the rotation axis of the motor 1-3. Even if the first winding 31 and the second winding 32 are wound as described above, an effect similar to that of the motor 1-2 can be achieved.

[0073] When the second windings 32 are wound in a sequence starting from the 3:00 position on the illustration Fig. 9 counterclockwise, a second winding 32U, a second winding 32V, a second winding 32V (overbar), a second winding 32W (overbar), a second winding 32U (overbar), a second winding 32U, a second winding 32V, a second winding 32W, a second winding 32W (overbar), a second winding 32U (overbar), a second winding 32V (overbar), a second winding 32V, a second winding 32W, a second winding 32U, a second winding 32U (overbar), a second winding 32V (overbar), a second winding 32V, a second winding 32W, a second winding 32U, a second winding 32U (overbar), a second winding 32V (overbar), a second winding 32W (overbar) and a second winding 32W, the above effect cannot be obtained.The arrangement of the second windings 32 must be designed taking into account the relationship to the first windings 31, so that the first windings 31 wound around the teeth 14 on both sides have the same phase and opposite directions of energization, and the second windings 32 wound around the teeth 14 on both sides of the slot 15 have the same phase and opposite directions of energization.

[0074] As described above, according to the second embodiment, the engine system 100 using the engine 1-2 instead of the engine 1 of Fig. 1. Although the motor system 100 including the motor 1-2 will be described below, the same applies to the motor system 100 including the motor 1-3 instead of the motor 1-2. The motor 1-2 includes the rotor 10 in which the permanent magnet 11, which is a magnetic flux generator that generates a magnetic flux, is arranged, and the stator 12 arranged facing the rotor 10. The stator 12 includes the return yoke 13 arranged facing the rotor 10 and the plurality of teeth 14 projecting from the return yoke 13 toward the rotor 10 and arranged adjacent to each other at intervals in the rotation direction of the rotor 10. In addition, the motor 1 includes the first winding 31 wound around the stator 12 and the plurality of magnetic sensors 17 provided in the slots 15, which are spaces between adjacent teeth 14, to measure a magnetic flux density.The control unit 2 includes the calculation unit 21, which obtains the rotation angle and / or the eccentricity of the rotor 10 based on signals from the plurality of magnetic sensors 17. The signal of the magnetic sensor 17 used by the calculation unit 21 is a signal from the magnetic sensor 17 provided in the slot 15 in which the first windings 31 on both sides have the same phase and opposite energization directions. By providing the magnetic sensor 17 in the slot 15 in which the first windings 31 on both sides have the same phase and opposite energization directions, the signal from the magnetic sensor 17 is the one in which the influence of one of the first windings 31 on both sides is canceled by the influence of the other first winding 31, even when the first winding 31 is energized.Accordingly, it is possible to reduce the detection error of information about a detection target, which is the rotation angle and / or eccentricity.

[0075] Furthermore, in the second embodiment, the magnetic sensor 17 is arranged within the groove 15, that is, between the adjacent teeth 14, and closer to the return yoke 13 in the radial direction R around the rotation axis of the motor 1 than to the tip of the teeth 14. As a result, the spatial harmonic component of the signal from the magnetic sensor 17 can be significantly reduced, and the detection error of information about a detection target, which is the rotation angle and / or eccentricity, can be reduced.

[0076] Additionally, the motor 1-2 includes three pairs of magnetic sensors 17, each including a first sensor and a second sensor, and the calculation unit 21 calculates the sum or difference between a signal of the first sensor and a signal of the second sensor in each pair. As a result, the influence of the space harmonic component of a multiple of three from the permanent magnet 11 and the influence of the magnetic flux generated by energizing the first winding 31 are removed from the rotation angle and eccentricity output from the calculation unit 21. Accordingly, it is possible to reduce the detection error of information about a detection target, which is the rotation angle and / or eccentricity.

[0077] The number of slots 15 in the motor 1-2 is 18, which satisfies the condition of a multiple of six, that is, twelve or more. The motor 1-2 satisfies the condition that the number of pole pairs of the permanent magnet 11 as a magnetic flux generator and the number of pole pairs generated by the winding 16 is 8, which is greater than 6, that is, 1 / 3 times the number of slots 18, and less than 12, that is, 2 / 3 times the number of slots 18. By setting the number of slots and the number of pole pairs to satisfy such conditions, the magnetic sensor 17 can be arranged in the slots 15 in which the first windings 31 on both sides have the same phase and opposite energization directions. Accordingly, it is possible to reduce the detection error of information about a detection target, which is the rotation angle and / or eccentricity.

[0078] According to the second embodiment, the motor 1-2 further includes the second winding 32 wound around the stator 12. The condition is satisfied that the number of pole pairs "7" generated by the second winding 32 is one greater than the number of pole pairs "8" of the permanent magnet 11, that is, the magnetic flux generator, or one less than the number of pole pairs "8" of the permanent magnet 11. The condition is satisfied that the number of pole pairs "7" generated by the second winding 32 is greater than "6", which is 1 / 3 times the number of slots "18", and less than "12", which is 2 / 3 times the number of slots "18". By setting the number of slots and the number of pole pairs to satisfy such conditions, the magnetic sensor 17 can be arranged in the slots 15 in which the second windings 32 on both sides have the same phase and opposite directions of energization.Accordingly, it is possible to reduce the detection error of information about a detection target, which is the rotation angle and / or eccentricity. Third embodiment.

[0079] Fig. 11 is a diagram illustrating a cross-sectional configuration of a motor 1-4 according to the third embodiment. Like the motor 1-2 according to the second embodiment, the motor 1-4 includes two types of windings, the first winding 31 and the second winding 32. In the motor 1-2, both the first winding 31 and the second winding 32, which are wound around the teeth 14 on both sides of the groove 15 in which the magnetic sensor 17 is arranged, are characterized by having the same phase and opposite energization directions.In contrast, in the motor 1-4, the first windings 31 wound around the teeth 14 on both sides of the slot 15 in which the magnetic sensor 17 is arranged are characterized by having the same phase and opposite energization directions, whereas the second windings 32 wound around the teeth 14 on both sides of the slot 15 in which the magnetic sensor 17 is arranged have different phases. Note that, as in the first embodiment, the signal of the magnetic sensor 17 is output to the calculation unit 21 of the control unit 2. A detailed description of this will be given below.

[0080] The motor 1-4 includes the rotor 10, the permanent magnet 11 arranged in the rotor 10, the stator 12 having the return yoke 13 and the teeth 14, and the magnetic sensor 17 arranged in the slot 15, which is a space between adjacent teeth 14. The first winding 31 and the second winding 32 are wound around the teeth 14. The first winding 31 and the second winding 32 are wound in an overlapping manner; here, the first winding 31 is wound outside the second winding 32. The rotor 10 includes the 10-pole permanent magnet 11. The number of slots 15 of the stator 12 is 12.

[0081] The first winding 31 is wound around the 12 teeth 14 to generate a magnetic field with 10 poles. The second winding 32 is wound around the 12 teeth 14 to generate a magnetic field with 8 poles. The first windings 31 are arranged in a sequence starting from the 3:00 position on the diagram. Fig. 11 counterclockwise, a first winding 31U, a first winding 31U (overline), a first winding 31V (overline), a first winding 31V, a first winding 31W, a first winding 31W (overline), a first winding 31U (overline), a first winding 31U, a first winding 31V, a first winding 31V (overline), a first winding 31W (overline) and a first winding 31W. The second windings 32 are arranged in a sequence starting from the 3:00 position on the illustration. Fig. 11 counterclockwise a second winding 32U, a second winding 32V, a second winding 32W, a second winding 32U, a second winding 32V, a second winding 32W, a second winding 32U, a second winding 32V and a second winding 32W.

[0082] The number of pole pairs generated by the second winding 32 is four, and the number of pole pairs of the permanent magnet 11 is five. At this time, the condition that the number of pole pairs generated by the second winding 32 is one greater or one less than the number of pole pairs of the permanent magnet 11 is satisfied.

[0083] The motor 1-4 includes the six magnetic sensors 17-1 to 17-6. The magnetic sensor 17-1 is arranged between the first winding 31U and the first winding 31U (oversweep). The magnetic sensor 17-2 is arranged between the first winding 31V and the first winding 31V (oversweep). The magnetic sensor 17-3 is arranged between the first winding 31W and the first winding 31W (oversweep). The magnetic sensor 17-4 is arranged between the first winding 31U and the first winding 31U (oversweep). The magnetic sensor 17-5 is arranged between the first winding 31V and the first winding 31V (oversweep). The magnetic sensor 17-6 is arranged between the first winding 31W and the first winding 31W (oversweep).

[0084] The magnetic sensor 17-1 is arranged between the second winding 32U and the second winding 32V. The magnetic sensor 17-2 is arranged between the second winding 32W and the second winding 32U. The magnetic sensor 17-3 is arranged between the second winding 32V and the second winding 32W. The magnetic sensor 17-4 is arranged between the second winding 32U and the second winding 32V. The magnetic sensor 17-5 is arranged between the second winding 32W and the second winding 32U. The magnetic sensor 17-6 is arranged between the second winding 32V and the second winding 32W.

[0085] Here, the first windings 31 located on both sides of the magnetic sensor 17 satisfy the condition of having the same phase and opposite energization directions, but the second windings 32 located on both sides of the magnetic sensor 17 have different phases. Therefore, when considered alone, the signal of the magnetic sensor 17 is affected by the energization of the second winding 32. Therefore, the calculation unit 21 of the control unit 2 treats two magnetic sensors 17 as a pair and calculates the difference between the two signals of the pair of magnetic sensors 17 to cancel the influence of the second winding 32. Here, two magnetic sensors 17 having the same combination of phases of the second windings 32 located on both sides of the magnetic sensor 17 are treated as a pair of magnetic sensors 17.

[0086] For example, the magnetic sensor 17-1 and the magnetic sensor 17-4 are both arranged between the second winding 32U and the second winding 32V. Here, the influence of the second winding 32 on the magnetic sensor 17-1 is expressed as ki u +ki v where k is a coefficient, i u a current of phase U and i v is a current of phase V. Similarly, the influence of the second winding 32 on the magnetic sensor 17-4 is also referred to as ki u +ki v Therefore, when the magnetic sensor 17-1 and the magnetic sensor 17-4 are treated as a pair and the difference between the signal of the magnetic sensor 17-1 and the signal of the magnetic sensor 17-4 is calculated, the influences of the second windings 32 are canceled, and only the magnetic flux component of the permanent magnet 11 of the rotor 10 can be extracted.

[0087] Similarly, the magnetic sensor 17-2 and the magnetic sensor 17-5 are both arranged between the second winding 32W and the second winding 32U. The magnetic sensor 17-3 and the magnetic sensor 17-6 are both arranged between the second winding 32V and the second winding 32W. Therefore, by treating the magnetic sensor 17-2 and the magnetic sensor 17-5 as a pair and treating the magnetic sensor 17-3 and the magnetic sensor 17-6 as a pair, it is possible to cancel the influence of the second winding 32U.

[0088] Fig. 12 is a diagram illustrating a cross-sectional configuration of a motor 1-5 according to a modification of the third embodiment. The configuration of the motor 1-5 is similar to that of the motor 1-4, except that the method for winding the first winding 31 and the second winding 32 around the teeth 14 is different from that of the motor 1-4. The first winding 31 of the motor 1-5 is wound in the second winding 32 in the radial direction R around the rotation axis of the motor 1-5. Even if the first winding 31 and the second winding 32 are wound as described above, a similar effect to that of the motor 1-4 can be obtained by treating two magnetic sensors 17 as a pair.

[0089] As described above, according to the third embodiment, the engine system 100 using the engine 1-4 instead of the engine 1 of Fig. 1. Although the motor system 100 including the motor 1-4 will be described below, the same applies to the motor system 100 including the motor 1-5 instead of the motor 1-4. The motor 1-4 includes the rotor 10 in which the permanent magnet 11, which is a magnetic flux generator that generates a magnetic flux, is arranged, and the stator 12 arranged facing the rotor 10. The stator 12 includes the return yoke 13 arranged facing the rotor 10 and the plurality of teeth 14 projecting from the return yoke 13 toward the rotor 10 and arranged adjacent to each other at intervals in the rotation direction of the rotor 10. In addition, the motor 1 includes the first winding 31 wound around the stator 12 and the plurality of magnetic sensors 17 provided in the slots 15, which are spaces between adjacent teeth 14, to measure a magnetic flux density.The control unit 2 includes the calculation unit 21, which obtains the rotation angle and / or the eccentricity of the rotor 10 based on signals from the plurality of magnetic sensors 17. The signal of the magnetic sensor 17 used by the calculation unit 21 is a signal from the magnetic sensor 17 provided in the slot 15 in which the first windings 31 on both sides have the same phase and opposite energization directions. By providing the magnetic sensor 17 in the slot 15 in which the first windings 31 on both sides have the same phase and opposite energization directions, the signal from the magnetic sensor 17 is the one in which the influence of one of the first windings 31 on both sides is canceled by the influence of the other first winding 31, even when the first winding 31 is energized.Accordingly, it is possible to reduce the detection error of information about a detection target, which is the rotation angle and / or eccentricity.

[0090] Furthermore, in the third embodiment, the magnetic sensor 17 is arranged within the groove 15, that is, between the adjacent teeth 14, and closer to the return yoke 13 in the radial direction R around the rotation axis of the motor 1 than to the tip of the teeth 14. As a result, the spatial harmonic component of the signal of the magnetic sensor 17 can be significantly reduced, and the detection error of information about a detection target, which is the rotation angle and / or eccentricity, can be reduced.

[0091] Additionally, the motor 1-4 includes three pairs of magnetic sensors 17, each including a first sensor and a second sensor, and the calculation unit 21 calculates the sum or difference between a signal of the first sensor and a signal of the second sensor in each pair. As a result, the influence of the space harmonic component of a multiple of three from the permanent magnet 11 and the influence of the magnetic flux generated by energizing the first winding 31 are removed from the rotation angle and eccentricity output from the calculation unit 21. Accordingly, it is possible to reduce the detection error of information about a detection target, which is the rotation angle and / or eccentricity.

[0092] The number of slots 15 in the motor 1-4 is 12, which satisfies the condition of a multiple of six, that is, twelve or more. The motor 1-4 satisfies the condition that the number of pole pairs of the permanent magnet 11 as a magnetic flux generator and the number of pole pairs generated by the winding 16 is 5, which is greater than 4, that is, 1 / 3 times the number of slots 12, and less than 8, that is, 2 / 3 times the number of slots 12. By setting the number of slots and the number of pole pairs to satisfy such conditions, the magnetic sensor 17 can be arranged in the slots 15 in which the first windings 31 on both sides have the same phase and opposite energization directions. Accordingly, it is possible to reduce the detection error of information about a detection target, which is the rotation angle and / or eccentricity.

[0093] According to the second embodiment, the motor 1-4 further includes the second winding 32 wound around the teeth 14. The condition is satisfied that the number of pole pairs "4" generated by the second winding 32 is one greater than the number of pole pairs "5" of the permanent magnet 11, that is, the magnetic flux generator, or one less than the number of pole pairs "5" of the permanent magnet 11. In addition, the phases of the second windings 32 on both sides of the slot 15 in which the magnetic sensor 17 is provided are different from each other.The calculation unit 21 can cancel the influence of the magnetic flux from the second winding 32 on the signal 17 of the magnetic sensor 17 by calculating the sum or difference between the signal of the first sensor, which is one of the plurality of magnetic sensors 17 included in the motor 1-4, and the signal of the second sensor arranged between the second windings 32 of the same phase combination as the phase combination of the second windings 32 on both sides of the slot 15 in which the first sensor is provided. Therefore, it is possible to reduce the detection error of information about a detection target, which is the rotation angle and / or eccentricity. Fourth embodiment.

[0094] Fig. 13 is a diagram illustrating a configuration of a control unit 2-1 according to the fourth embodiment. The control unit 2-1 includes the calculation unit 21, a correction unit 22, and a storage unit 23. Here, the signal of the magnetic sensor 17 disposed in the motor 1 is input to the control unit 2-1, but the signal input to the control unit 2-1 may be a signal of the magnetic sensor 17 disposed in any of the motors 1-1 to 1-5.

[0095] The correction unit 22 has a function of correcting an influence on the signal of the magnetic sensor 17 due to a change in the amount of current applied to the windings 16 located on both sides of the magnetic sensor 17.

[0096] The storage unit 23 stores the change amount of the signal from the magnetic sensor 17, which corresponds to the current supply amount. This change amount is calculated based on the signal from the magnetic sensor 17 actually detected when the current supply amount to the winding 16 is changed.

[0097] Fig. Figure 14 is a diagram illustrating an example of a relationship between the current applied to the winding 16 and the signal from the magnetic sensor 17. The horizontal axis of Fig. 14 is the current i n , which flows through the winding 16. Here, n of the current i n any of the phases U, V, and W, which are phases of the windings 16 arranged on both sides of the magnetic sensor 17, or may be a value obtained by performing four arithmetic operations on a plurality of three-phase currents. In Fig. 14 the vertical axis represents the signal Sn of the magnetic sensor 17. Here, n of the signal S n a sensor number or a value obtained by performing four arithmetic operations on the signals of the plurality of magnetic sensors 17. The intercept on the vertical axis represents a term contributed by the rotor 10. This value changes as the rotor 10 rotates.

[0098] Even if the current supply amount to the windings 16 located on both sides of the magnetic sensor 17 changes, the influence of the windings 16 on both sides of the magnetic sensor 17 is ideally canceled by the influence of one winding 16 and the influence of the other winding 16, and the signal of the magnetic sensor 17 is independent of the value of the current i n constant. In practice, the influence of the current i nHowever, due to an asymmetry caused by a difference in the winding bulge of the windings 16 located on both sides of the magnetic sensor 17, a misalignment of the magnetic sensor 17, and the like, the magnetic sensor 17 may not be completely eliminated. Therefore, as shown in Fig. 14 illustrates, the signal of the magnetic sensor 17 changes depending on the energization amount. As described above, this relationship is caused by an asymmetry of the winding 16, misalignment of the magnetic sensor 17, and the like, and thus differs between the motors 1. By disposing the magnetic sensor 17 in the slot 15 in which the windings 16 located on both sides have the same phase and opposite energization directions, the influence of the energization to the winding 16 on the magnetic sensor 17 can be greatly reduced, but the influence of the energization caused by the asymmetry of the winding 16, the misalignment of the magnetic sensor 17, and the like described above is liable to remain. The correction unit 22 corrects the influence of the energization due to an asymmetry of the winding 16, misalignment of the magnetic sensor 17, and the like through post-processing.

[0099] Fig. 15 is a diagram explaining the Fig. 13 illustrated correction unit 22. The correction unit 22 corrects the signal S n of the magnetic sensor 17 and outputs a corrected signal S n ' Assuming that there is a linearity between the current i n and the signal S n of the magnetic sensor 17 based on the relationship between the current i n and the signal S n , as in Fig. 14, for example, a relationship of S n =S n '+k n i n manufactured. Here is S n ' a term introduced by the rotor 10 in the signal S n which is output by the magnetic sensor 17 and corresponds to the intercept in Fig. 14. In addition, k n i n a term defined by the current i n of the stator 12. In Fig. 14 corresponds to the coefficient k n the increase. The coefficient k n can for example R n +L n as described above. Ideally, the coefficient k n =0.

[0100] Based on the actual measurement result, as in Fig. 14, the correction unit 22 can determine the coefficient k n for example, using the least squares method. The coefficient k n can also be calculated by simple calculation (S n1 -S n2 ) / (i n1 -i n2 ) based solely on the results (S n1 , i n1 ) and (S n2 , i n2 ) that were actually measured under two conditions.

[0101] After obtaining the coefficient k n the correction unit 22 can correct the signal of the magnetic sensor 17 by calculating “S n '=S n -k n i n”. Therefore, the correction unit 22 can correct the corrected signal S n ' based on the signal S n of the magnetic sensor 17 based on the information indicating the relationship between the energization amount and the change amount of the signal of the magnetic sensor 17 stored in the storage unit 23, and the corrected signal S n ' to the calculation unit 21.

[0102] In the above description, as in Fig. 14 illustrates the relationship between the current i n and the signal S n of the magnetic sensor 17 is described as being represented by a linear function, but besides the linear function, a quadratic function or the like may be used. Furthermore, an effect similar to that of the first embodiment can be achieved even without the correction unit 22, and thus the correction unit 22 can be omitted.

[0103] As described above, the control unit 2-1 according to the fourth embodiment includes the storage unit 23 that stores the relationship between the energization amount and the change amount of the signal of the magnetic sensor 17, which is obtained from the signal of the magnetic sensor 17 detected when the energization amount of the coil 16 is changed, and the correction unit 22 that corrects the signal of the magnetic sensor 17 based on the relationship between the energization amount and the change amount of the signal of the magnetic sensor 17 stored in the storage unit 23. Here, the information indicating the relationship between the energization amount and the change amount of the signal of the magnetic sensor 17, for example, the coefficient k nor the amount of change in the signal of the magnetic sensor 17 corresponding to each energization amount. With such a configuration, even if the signal of the magnetic sensor 17 changes due to a change in the energization amount to the coil 16, it is possible to reduce the detection error of information about a detection target, which is at least the rotation angle and / or the eccentricity amount, by correcting the signal of the magnetic sensor 17.

[0104] It should be noted that each of the Fig. 1 illustrated control unit 2 and the one in Fig.13 is implemented by a processing circuit. The processing circuit may be dedicated hardware or may be a control circuit using a central processing unit (CPU). The dedicated hardware for implementing the control units 2 and 2-1 corresponds, for example, to a single circuit, a compound circuit, a programmed processor, a programmed parallel processor, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or a combination thereof.

[0105] When the above processing circuit is implemented by a control circuit using a CPU, the control circuit may include a processor and a memory. The processor is a CPU and is also referred to as a processing device, arithmetic device, microprocessor, microcomputer, digital signal processor (DSP), or the like. Examples of the memory include a non-volatile or volatile semiconductor memory, a magnetic disk, a flexible disk, an optical disk, a compact disc, a mini disc, a digital versatile disc (DVD), and the like. Examples of non-volatile or volatile semiconductor memories include random access memory (RAM), read-only memory (ROM), flash memory, erasable programmable ROM (EPROM), electrically operated EPROM (EEPROM, registered trademark), and the like.

[0106] In a case where the above processing circuit is implemented by the control circuit, the processor reads and executes the program corresponding to the process of each component stored in the memory, thereby implementing the processing circuit. The memory is also used as temporary storage for each process executed by the processor.

[0107] The configurations described in the above-mentioned embodiments are examples. The embodiments can be combined with other well-known techniques and with each other, and some of the configurations can be omitted or changed within a range that does not deviate from the essence.

[0108] For example, in the above embodiments, the winding 16, the first winding 31, and the second winding 32 are wound around the teeth 14, but need only be wound around the stator 12, and may be wound, for example, around the return yoke 13. Even if they are wound around the return yoke 13, the winding 16, the first winding 31, and the second winding 32 are wound around both sides of each tooth 14 in the circumferential direction in which the teeth 14 are arranged, for example, so that they are located on both sides of the slot 15. List of reference symbols

[0109] 1, 1-1 to 1-5 Motor; 2, 2-1 Control unit; 10 Rotor; 11 Permanent magnet; 12 Stator; 13 Return yoke; 14 Teeth; 15 Slot; 16 Winding; 17, 17-1 to 17-6 Magnetic sensor; 18U, 19 Magnetic flux; 21 Calculation unit; 22 Correction unit; 23 Storage unit; 31 First winding; 32 Second winding; 100 Motor system. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2016-188700

[0004]

Claims

[1] A motor system comprising a motor and a control unit for controlling the motor, the motor including: a rotor in which a magnetic flux generator is arranged which generates a magnetic flux; a stator including a return yoke disposed facing the rotor and a plurality of teeth projecting from the return yoke toward the rotor and arranged adjacent to one another at intervals in a rotational direction of the rotor; a winding wound around the stator; and a plurality of magnetic sensors provided in grooves, which are spaces between adjacent teeth, for measuring a magnetic flux density, wherein the control unit includes: a calculation unit for obtaining a rotation angle and / or an eccentricity of the rotor based on signals from the plurality of magnetic sensors and a magnetic sensor signal used by the calculation unit is a magnetic sensor signal provided in the slot in which the windings on both sides have the same phase and opposite directions of energization. [2] The motor system of claim 1, wherein the magnetic sensor is disposed within the groove and closer to the return yoke than to a tip of the teeth. [3] Engine system according to claim 1, wherein the motor includes three pairs of magnetic sensors, each including a first sensor and a second sensor, and the calculation unit calculates a sum or a difference between a signal of the first sensor and a signal of the second sensor in each pair. [4] Engine system according to claim 1, wherein the number of grooves is a multiple of three, i.e. nine or more, and the number of pole pairs of the magnetic flux generator and the number of pole pairs generated by the winding is greater than 1 / 3 times the number of slots and less than 2 / 3 times the number of slots. [5] Engine system according to claim 1, wherein the number of grooves is a multiple of six, i.e. twelve or more, and the number of pole pairs of the magnetic flux generator and the number of pole pairs generated by the winding is greater than 1 / 3 times the number of slots and less than 2 / 3 times the number of slots. [6] Engine system according to claim 1, wherein the motor further includes a second winding wound around the stator, a number of pole pairs generated by the second winding is one greater than a number of pole pairs of the magnetic flux generator or one less than a number of pole pairs of the magnetic flux generator and a signal of the magnetic sensor used by the calculation unit is a signal of the magnetic sensor provided in the slot in which the second windings on both sides have the same phase and opposite directions of energization. [7] Engine system according to claim 1, wherein the motor further includes a second winding wound around the stator, a number of pole pairs generated by the second winding is one greater than a number of pole pairs of the magnetic flux generator or one less than a number of pole pairs of the magnetic flux generator, phases of the second windings on both sides of the slot in which the magnetic sensor is provided differ from each other, and the calculation unit cancels an influence of a magnetic flux from the second winding by calculating a sum of or a difference between a signal of a first sensor, which is one of the plurality of magnetic sensors included in the motor, and a signal of a second sensor arranged between the second windings of a same combination of phases as a combination of phases of the second windings on both sides of the slot in which the first sensor is provided. [8] Engine system according to claim 1, wherein the control unit further includes: a storage unit for storing information indicating a relationship between the energization amount and a change amount of a signal of the magnetic sensor, the relationship being obtained from a signal of the magnetic sensor detected when the energization amount of the coil is changed; and a correction unit for correcting a signal of the magnetic sensor based on the relationship between the energization amount and the change amount of the signal of the magnetic sensor indicated by the information stored in the storage unit. [9] Engine, comprising: a rotor in which a magnetic flux generator is arranged which generates a magnetic flux; a stator including a return yoke disposed facing the rotor and a plurality of teeth projecting from the return yoke toward the rotor and arranged at intervals in a circumferential direction; a winding wound around the stator; and a plurality of magnetic sensors provided in grooves, which are spaces between adjacent teeth, wherein all of the plurality of magnetic sensors are provided in the slots in which the windings on both sides have the same phase and opposite directions of energization. [10] The engine of claim 9, further comprising: a second winding wound around the stator, wherein a number of pole pairs generated by the second winding is one greater than a number of pole pairs of the magnetic flux generator or one less than a number of pole pairs of the magnetic flux generator, a number of pole pairs generated by the second winding is greater than 1 / 3 times the number of slots and less than 2 / 3 times the number of slots and all of the plurality of magnetic sensors are provided in the slots in which the second windings on both sides have the same phase and opposite directions of energization. [11] The engine of claim 9, further comprising: a second winding wound around the stator, wherein a number of pole pairs generated by the second winding is one greater than a number of pole pairs of the magnetic flux generator or one less than a number of pole pairs of the magnetic flux generator, the magnetic sensor defines a first sensor and a second sensor as a pair of sensors, all of the pair of sensors are provided in the slots in which phases of the second windings on both sides differ from each other, and in each of the pair of sensors, a set of phases of the second windings located on both sides of the first sensor is the same as a set of phases of the second windings located on both sides of the second sensor.

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