JP2006074940A - Rotating electric machine and rotating electric machine application system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotating electrical machine that is reduced in size and improved in current detection accuracy and an application system thereof.
A rotating electrical machine 6 includes a U-phase coil 10, a sensor SU that detects a current flowing in the U-phase coil 10, a V-phase coil 12, a sensor SV that detects a current flowing in the V-phase coil 12, and a W Phase coil 14 and sensor SW for detecting a current flowing through W phase coil 14. Sensors SU, SW, and SV are magnetic field sensors, and detect a current flowing in the coil by detecting a magnetic field generated in the core portion of the U, V, and W phase coils. The detected current value is sent to the control device 3 as a signal MCRT1. The control device 3 controls the conduction of the switching elements inside the inverter 4 to convert the DC voltage into AC and supplies it to the rotating electrical machine 6.
[Selection] Figure 1

Description

  The present invention relates to a rotating electrical machine and a rotating electrical machine application system, and more particularly to current measurement of the rotating electrical machine.

  In recent years, there has been a demand for a small and efficient motor as a drive motor for electric vehicles and hybrid vehicles. The drive motor is controlled at a variable speed by an inverter and a control device. In the variable speed control, the motor current is measured.

On the other hand, regarding an engine-driven automobile, Japanese Patent Publication No. 2001-510257 (Patent Document 1) discloses a configuration in which a magnetic field sensor is provided in a core outside a motor for measuring the current of a starting motor.
Special table 2001-510257 gazette Japanese Utility Model Publication No. 63-88073 Japanese Utility Model Publication No. 2-57279

  Since the configuration disclosed in Japanese Patent Publication No. 2001-510257 (Patent Document 1) is provided with a magnetic field sensor in the core outside the motor, in terms of downsizing the apparatus and accurately measuring the current. There was room for improvement.

  An object of the present invention is to provide a rotating electrical machine that is reduced in size and improved in current detection accuracy and an application system thereof.

  In summary, the present invention is a rotating electrical machine, and includes a rotor and a stator used in combination with the rotor. The stator includes a coil, a stator core portion around which the coil is wound, and a sensor that is provided in the stator core portion and detects a current of the coil by detecting a magnetic field.

  Preferably, the stator core portion is provided with a recess for accommodating the sensor.

  Preferably, the sensor is resin-molded and fixed to the stator core portion.

  Preferably, the stator further includes a magnetic shielding part that is provided around the sensor and shields a magnetic field that intersects the magnetic field generated by the coil.

  Preferably, the recess has an opening that is narrower than the bottom.

  Preferably, the sensor and the stator core part are provided with an uneven part that determines the position of the sensor with respect to the stator core when combined.

  Preferably, the sensor and the stator core portion are provided with a fitting portion having a shape that determines the position of the sensor with respect to the stator core by being fitted and generates resistance when the sensor and the stator core are once fitted.

  Preferably, the concave portion is provided in a small protrusion protruding from the stator core portion.

  When the other situation of this invention is followed, it is a rotary electric machine application system, Comprising: The rotary electric machine containing the stator used in combination with a rotor and a rotor is provided. The stator includes a coil, a stator core portion around which the coil is wound, and a sensor that is provided in the stator core portion and detects a current of the coil by detecting a magnetic field. The rotating electrical machine application system further includes a control unit that performs coil current control in accordance with the output of the sensor.

  According to the present invention, downsizing of a rotating electrical machine and reliability of current detection accuracy are improved. In addition, current detection noise due to magnetic interference can be reduced. Furthermore, positioning of the sensor attachment is facilitated, and the magnetic sensor can be prevented from falling off.

  Hereinafter, the present invention will be described in detail with reference to the drawings. The same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

[Embodiment 1]
FIG. 1 is a block diagram showing a configuration of a rotating electrical machine application system 1 to which the rotating electrical machine of the present invention is applied.

  Referring to FIG. 1, a rotating electrical machine application system 1 includes a DC power supply 2 that supplies a DC voltage, an inverter 4 that converts a DC supplied from the DC power supply 2 into a three-phase AC, and a rotation driven by the inverter 4. It includes an electric machine 6 and a control device 3 that receives a signal MCRT1 indicating the value of a current flowing through the coil portion of the rotating electric machine 6 and controls the inverter 4 in response thereto.

  The rotating electrical machine 6 includes a U-phase coil 10, a sensor SU that detects a current flowing through the U-phase coil 10, a V-phase coil 12, a sensor SV that detects a current flowing through the V-phase coil 12, and a W-phase coil 14. And a sensor SW for detecting a current flowing through the W-phase coil 14.

  Specific examples of the rotating electrical machine application system 1 include an automobile in which wheels are driven by a motor such as an electric vehicle and a hybrid vehicle. This motor acts as a generator during vehicle braking and outputs electric power to a DC power source.

  Sensors SU, SW, and SV are magnetic field sensors, and detect a current flowing in the coil by detecting a magnetic field generated in the core portion of the U, V, and W phase coils.

  The detected current value is sent to the control device 3 as a signal MCRT1. The control device 3 controls the conduction of the switching element inside the inverter 4 to convert the DC voltage into AC and supplies it to the rotating electrical machine 6.

  FIG. 2 is a view showing a cross section of the rotating electrical machine 6 perpendicular to the rotating shaft.

  Referring to FIG. 2, rotating electrical machine 6 includes a shaft 9 that is a rotating shaft, a rotor 8 that is coupled to shaft 9, and a stator 5 that is fixed to a case (not shown).

  The stator 5 is formed by laminating electromagnetic steel plates, for example. The stator 5 is provided with twelve protrusions.

  A U-phase coil 10 is wound around the protrusion 20. A V-phase coil 12 is wound around the protrusion 22. W-phase coil 14 is wound around protrusion 24.

  A sensor SU is disposed in a recess provided on the surface of the protrusion 20. A sensor SV is disposed in a recess provided on the surface of the protrusion 22. Similarly, a sensor SW is disposed in a recess provided on the surface of the protrusion 24. The sensors SU, SV, and SW are magnetic field sensors, and currents flowing through the U-phase coil 10, the V-phase coil 12, and the W-phase coil 14 can be detected by observing changes in the magnetic field, respectively.

  A rotor 8 is accommodated in a cavity inside the stator 5. The rotor 8 is formed, for example, by laminating electromagnetic steel plates, and permanent magnets 7 are inserted into eight cavities provided in the electromagnetic steel plates.

  When a three-phase alternating current is applied to the U-phase coil 10, the V-phase coil 12, and the W-phase coil 14, the rotor 8 rotates about the center of the shaft 9 by the force generated between each coil and the permanent magnet 7. .

  In addition, although the case where the rotary electric machine 6 is a motor has been described, it may be a generator that generates electricity in the coil of the stator by rotating the rotor by an external force.

  FIG. 3 is a view for explaining the relationship between U-phase coil 10 and stator 6 in FIG.

  Referring to FIG. 3, stator 6 is formed by laminating electromagnetic steel sheets, for example. This electromagnetic steel sheet is provided with protrusions. A coil 10 that has been wound in advance is fitted into a substantially rectangular parallelepiped protrusion 20 formed by integrating the protrusions of an electromagnetic steel sheet.

  The coil 10 is fixed to the stator 6 by a resin mold or a ring for preventing the coil 10 from being fitted into the protrusion 20.

  A depression is provided in the central portion of the surface of the protrusion 20, and the magnetic field sensor SU is provided there. Such a depression can be easily formed if a part of the laminated electromagnetic steel sheet is provided with a cut in accordance with the depth of the sensor.

  Similarly, the V-phase coil 12 and the W-phase coil 14 are respectively attached to the protrusions 22 and 24, and the sensors SV and SW are attached to the depressions on the surface of the protrusion.

  FIG. 4 is a diagram for explaining the relationship between the current flowing through the coil and the magnetic field of the stator core.

  Referring to FIG. 4, when current i flows through coil 10, a magnetic field in the direction of the excitation field indicated by an arrow is generated at protrusion 20 of the stator, which is an iron core at the center of coil 10. The magnetic field produced by the motor core is detected by arranging the sensor SU on the iron core. Since the intensity of the magnetic field changes according to the magnitude of the current i, the magnitude of the current i is determined from the output of the magnetic field sensor SU. Therefore, the motor current can be calculated and used for motor control.

  The magnetic field sensor SU may be a Hall sensor, for example, but a small and highly sensitive MI sensor, MR sensor, or the like can also be used.

  A current sensor using a conventional Hall IC has a core for collecting magnetic flux in the sensor itself. However, the provision of a magnetic flux collecting core dedicated to the sensor hinders miniaturization of the motor. However, if the magnetic field sensor is used as it is without a magnetic collecting core, magnetic field interference from other sources occurs.

  In addition, since magnetic field sensors such as MI sensors are highly sensitive, measured values differ depending on the position. For this reason, in order to perform stable motor control without variation, accurate positioning of the magnetic field sensor is required.

  As described above, there is a point to consider when attempting to use a highly sensitive magnetic field sensor directly without a magnetic collecting core.

  In the first embodiment, a core only for a sensor is not provided, and a motor core is also used as a sensor core. The position of the magnetic field sensor may be attached to the surface, or may be embedded by providing a hole. In order to prevent magnetic field interference from others, it is desirable to provide holes or depressions and bury them.

  FIG. 5 is a view showing a cross section of the protrusion 20 near the sensor SU in FIG.

  With reference to FIG. 5, the protrusion 20 is provided with a hole in which the magnetic field sensor SU can be embedded. The hole can be easily formed by cutting a part of the electromagnetic steel sheet.

  Accordingly, the magnetic sensor is surrounded by the magnetic steel plate of the motor core, and magnetic interference from other portions can be prevented by the electromagnetic shielding effect. And with a surrounding electromagnetic steel plate, a uniform magnetic flux is obtained and a stronger magnetic field can be obtained.

  The sensor may be embedded in the vicinity of the surface or in the deep part of the core. However, if the sensor is embedded in the deep part, the number of cut portions of the electromagnetic steel sheet increases and causes a decrease in magnetic force.

  As described above, the rotating electrical machine of the first embodiment can measure a high-density magnetic flux having a strong magnetomotive direction without having a special magnetic flux collecting core for a current sensor. . Thereby, highly accurate current detection and the miniaturization of a motor can be made compatible.

[Embodiment 2]
FIG. 6 is a diagram for explaining a magnetic field sensor embedded portion according to the second embodiment.

  Referring to FIG. 6, in Embodiment 2, the magnetic field sensor is molded with resin 30. This resin 30 can serve both as a sealing material for the bare chip 32 and the wiring 36 disposed on the printed wiring board 34 and for fixing the magnetic field sensor to the protrusion 20. As a result, the magnetic field sensor can be positioned and the sealing process of the magnetic field sensor can be omitted.

[Embodiment 3]
FIG. 7 is a cross-sectional view of the vicinity of the magnetic field sensor in the third embodiment.

  Referring to FIG. 7, a magnetic shielding material 40 such as permalloy is provided on the wall surface of the hole provided in protrusion 20, and magnetic field sensor SU is provided therebetween. Thereby, the magnetic flux in the excitation field direction is detected, but the magnetic flux that does not coincide with the excitation field direction, that is, the magnetic flux that intersects the excitation field direction is cut off, and magnetic interference, noise, and the like can be cut.

  Therefore, the magnetic field sensor can be positioned, and the current detection accuracy can be improved.

[Embodiment 4]
FIG. 8 is a diagram for explaining a magnetic sensor mounting structure according to the fourth embodiment.

  Referring to FIG. 8, the protrusion 50 of the stator is provided with a recess for receiving the sensor, and the bottom thereof is provided with a protrusion for fitting with the sensor SUA. Correspondingly, the bottom of the sensor SUA is provided with a recess that meshes with the small protrusion. By doing so, attachment can be performed easily, positioning can be performed, and positioning accuracy can be further improved. As a result, current measurement accuracy can be improved.

[Embodiment 5]
FIG. 9 is a diagram for explaining a magnetic sensor mounting structure according to the fifth embodiment.

  Referring to FIG. 9, a recess for accommodating a magnetic field sensor is provided in the protrusion 60 of the stator, and a lock mechanism that engages with the magnetic field sensor SUB is provided at the bottom of the recess. This lock mechanism has a shape that is not easily dropped once the sensor is fitted.

  That is, the position of the magnetic field sensor with respect to the stator core is determined by being fitted, and a fitting portion having a shape that generates resistance when removed once fitted is provided on the protrusion of the sensor and the stator.

  Thereby, positioning becomes possible and further simplification of sensor mounting is achieved. As a result, positioning accuracy is improved, current measurement accuracy can be improved, and motor assembly is simplified.

[Embodiment 6]
FIG. 10 is a diagram for explaining a sensor mounting portion in the sixth embodiment.

  Referring to FIG. 10, the projection 70 of the stator is provided with a recess for accommodating the sensor SU. The shape of this depression is a structure in which the upper part which is an opening is narrower than the bottom part of the depression. Such a shape can be expected to reduce interference when magnetism wraps around.

  In other words, when magnetism enters the hole into which the sensor is inserted, when the reflection of the magnetism or the magnetization of the inner wall occurs, the effect from there is considered to be less oblique to the sensor. Because. For this reason, noise is cut and current measurement accuracy is improved.

[Embodiment 7]
In the first to sixth embodiments, the case where the sensor is accommodated in the protrusion of the stator and the depression that is convenient for positioning is provided, but other structures are conceivable as long as the sensor is positioned and noise is reduced.

  FIG. 11 is a diagram for explaining a sensor mounting portion in the seventh embodiment.

  Referring to FIG. 11, the protrusions 80 of the stator are provided with protrusions 90 positioned on both sides of the magnetic sensor SU to accommodate the magnetic sensor. If protrusions 90 are provided on a part of the electromagnetic steel sheet and protrusions having a shape that covers the sensor SU are provided on the upper and lower electromagnetic steel sheets, a wall surrounding the sensor is formed on the protrusion of the stator.

  Thereby, a hollow is provided in the small protrusion which protrudes from a stator core part, and a magnetic sensor is accommodated in this.

  By doing in this way, the effect similar to Embodiment 1 can be acquired.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is the block diagram which showed the structure of the rotary electric machine application system 1 to which the rotary electric machine of this invention is applied. It is the figure which showed the cross section of the rotary electric machine 6 perpendicular | vertical to a rotating shaft. It is a figure for demonstrating the relationship between the U-phase coil 10 and the stator 6 in FIG. It is a figure for demonstrating the relationship between the electric current which flows through a coil, and the magnetic field of a stator core. It is the figure which showed the cross section of the projection part 20 vicinity of the sensor SU in FIG. It is a figure for demonstrating the magnetic field sensor embedding part in Embodiment 2. FIG. FIG. 10 is a cross-sectional view of the vicinity of a magnetic field sensor in a third embodiment. It is a figure for demonstrating the attachment structure of the magnetic field sensor in Embodiment 4. FIG. It is a figure for demonstrating the attachment structure of the magnetic field sensor in Embodiment 5. FIG. It is a figure for demonstrating the sensor attachment part in Embodiment 6. FIG. It is a figure for demonstrating the sensor attachment part in Embodiment 7. FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Rotating electrical machine application system 2 DC power supply 3 Control device 4 Inverter 5 Stator 6 Rotating electrical machine 7 Permanent magnet 8 Rotor 9 Shaft 10 U phase coil 12 V phase coil 14 W phase coil 20 , 22, 24, 50, 60, 70, 80, 90 Protrusion, 30 Resin, 32 Bare chip, 34 Printed wiring board, 36 Wiring, 40 Magnetic shielding material, SU, SV, SW, SUA, SUB sensor.

Claims (9)

A rotor,
A stator used in combination with the rotor,
The stator is
Coils,
A stator core portion around which the coil is wound;
A rotating electrical machine including a sensor provided in the stator core portion and detecting a current of the coil by detecting a magnetic field.   The rotating electrical machine according to claim 1, wherein the stator core portion is provided with a recess that houses the sensor.   The rotating electrical machine according to claim 1, wherein the sensor is resin-molded and fixed to the stator core portion. The stator is
The rotating electrical machine according to any one of claims 1 to 3, further comprising a magnetic shielding portion that is provided around the sensor and shields a magnetic field that intersects a magnetic field generated by the coil.   The rotating electrical machine according to any one of claims 1 to 4, wherein the recess has an opening narrower than a bottom.   The rotating electrical machine according to any one of claims 1 to 5, wherein the sensor and the stator core portion are provided with an uneven portion that determines a position of the sensor with respect to the stator core by being combined.   The sensor and the stator core part are provided with a fitting part having a shape such that a position of the sensor with respect to the stator core is determined by being fitted and resistance is generated when the sensor and the stator core are once fitted. The rotary electric machine of any one of -6.   The rotating electrical machine according to claim 1, wherein the concave portion is provided in a small protrusion protruding from the stator core portion. A rotating electric machine including a rotor and a stator used in combination with the rotor;
The stator is
Coils,
A stator core portion around which the coil is wound;
A sensor provided on the stator core portion and detecting a current of the coil by detecting a magnetic field;
A rotating electrical machine application system further comprising a control unit that performs current control of the coil in accordance with an output of the sensor.

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