JP6991298B1 - Current detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate a current generated by a magnetic flux of a rotor in a current detecting device for detecting a current flowing through a plurality of sets of multi-phase armature windings by each magnetic sensor arranged at a position where magnetic fluxes radially radiated from the rotor intersect. Provided is a current detection device capable of suppressing deterioration of output torque control accuracy due to a current detection error. SOLUTION: A radial orthogonal plane which is a plane orthogonal to the radial direction passing through each magnetic sensor so that a positive / negative sign of a first set of ripple components and a positive / negative sign of a second set of ripple components are different from each other. A current detector in which the tilt angle in the magnetic flux detection direction of the magnetic sensor of each phase of each set is set. [Selection diagram] FIG. 4

Description

The present application relates to a current detection device.

For example, there is a current detection device that detects the current of the winding of each phase of an AC rotating machine having two sets of three-phase windings by using a magnetic sensor. However, the magnetic sensor of each phase may be mixed with the disturbance magnetic flux due to the current of the other phase, and a current detection error may occur. Various configurations have been proposed to reduce this error.

For example, in the current detection device described in Patent Document 1, the current path of one phase is formed in a U shape, and the first magnetic flux is formed in the first facing portion and the second facing portion in which the directions of the currents are opposite to each other. A sensor and a second magnetic sensor are arranged to reduce the current detection error caused by the disturbance magnetic flux.

Japanese Unexamined Patent Publication No. 2018-96795

However, in the technique of Patent Document 1, two magnetic sensors are required to detect the current of one phase. For example, in the case of an AC rotating machine having two sets of three-phase windings, twelve magnetic sensors are required, which increases the cost and increases the cost as compared with the case where each phase is detected by one magnetic sensor. Becomes larger.

Further, like a Randell type rotor, when one side portion in the axial direction of the rotor becomes an N pole or an S pole and each magnetic sensor is arranged on one side in the axial direction of the rotor, each magnetic sensor The magnetic fluxes radiated radially from the rotor intersect. The magnetic flux of this rotor may cause a current detection error in each magnetic sensor.

Therefore, the present application applies to the magnetic flux of the rotor in a current detection device that detects the current flowing through two sets of multi-phase armature windings by each magnetic sensor arranged at a position where the magnetic fluxes radiated radially from the rotor intersect. It is an object of the present invention to provide a current detection device capable of suppressing deterioration of output torque control accuracy due to a current detection error caused by the above.

とし、
前記第２組のｎ相の電機子巻線において、第２組の第ｈ相の電機子巻線に対する電気角での前記ロータの磁極の位相をθｅｈ２とし、第２組の第ｈ相の前記磁気センサにより検出される前記ロータの磁束密度の成分であるロータ磁束密度の検出成分をＢｓｈ２としたとき、第２組のリプル成分であるＲ２を、

としたとき、
前記第１組のリプル成分の正負の符号と、前記第２組のリプル成分の正負の符号とが、互いに異なるように、各前記磁気センサを通る径方向に直交する平面である径直交平面に対する各組の各相の前記磁気センサの磁束検出方向の傾き角度が設定されているものである。 The current detection device according to the present application has a rotor and a stator provided with a first set of n-phase armature windings and a second set of n-phase armature windings (n is an integer of 3 or more). In an AC rotating machine, each set is based on the output signal of the magnetic sensor of each phase of each set arranged to face the connection line of each phase of each set that supplies current to the armature winding of each phase of each set. It is a current detection device that detects the current flowing in the armature winding of each phase of.
The magnetic sensor of each phase of each set is arranged at a position where magnetic fluxes radiated radially from the rotor intersect.
In the first set of n-phase armature windings, the phase of the magnetic flux of the rotor at the electrical angle with respect to the first set of k-phase armature windings is set to θek1, and the first set of k-phase said. When the detection component of the rotor magnetic flux density, which is the component of the magnetic flux density of the rotor detected by the magnetic sensor, is Bsk1, R1 which is the ripple component of the first set is used.

age,
In the second set of n-phase armature windings, the phase of the magnetic flux of the rotor at the electrical angle with respect to the second set of h-phase armature windings is set to θeh2, and the second set of h-phases is described. When the detection component of the rotor magnetic flux density, which is the component of the magnetic flux density of the rotor detected by the magnetic sensor, is Bsh2, the second set of ripple components R2 is used.

When
With respect to a radial orthogonal plane which is a plane orthogonal to the radial direction passing through each of the magnetic sensors so that the positive and negative codes of the first set of ripple components and the positive and negative codes of the second set of ripple components are different from each other. The tilt angle of each phase of each set in the magnetic flux detection direction of the magnetic sensor is set.

Detection of the detection error component of the detected value of the sum current of the d-axis, which is the sum of the current detection values of the d-axis of each set, and the detection of the sum of current of the q-axis, which is the sum of the current detection values of the q-axis of each set. The error component deteriorates the control accuracy of the output torque. However, the detected value of the sum current of the d-axis and the q-axis includes a detection error component due to the magnetic flux of the rotor, which is the sum of the ripple component of the first set and the ripple component of the second set. According to the current detection device according to the present application, the tilt angle in the magnetic flux detection direction of each magnetic sensor is such that the positive and negative signs of the first set of ripple components and the positive and negative signs of the second set of ripple components are different from each other. Since is set, the ripple component of the first set and the ripple component of the second set can cancel each other out, and the detection error due to the magnetic flux of the rotor included in the detection value of the sum current of the d-axis and the q-axis. The components can be reduced. Therefore, the control accuracy of the output torque can be improved by reducing the detection error component of the sum current of the d-axis and the q-axis.

It is a schematic block diagram of the AC rotary machine and the control device which concerns on Embodiment 1. FIG. It is a figure explaining the phase of the armature winding which concerns on Embodiment 1. FIG. It is a schematic block diagram of the control device which concerns on Embodiment 1. FIG. It is a figure explaining the arrangement of the magnetic sensor which concerns on Embodiment 1. FIG. It is a perspective view of the Randell type rotor which concerns on Embodiment 1. FIG. It is a schematic sectional drawing of the AC rotary machine which concerns on Embodiment 1. FIG. It is a figure explaining the magnetic flux detected by the magnetic sensor which concerns on Embodiment 1. FIG. It is a figure explaining the magnetic sensor provided with the magnetic collecting core which concerns on Embodiment 1. FIG. It is a figure explaining the arrangement of the magnetic sensor which concerns on Embodiment 1. FIG. It is a figure explaining the phase of the armature winding which concerns on Embodiment 1. FIG. It is a figure explaining the phase of the armature winding which concerns on Embodiment 2. It is a hardware block diagram of the control device which concerns on Embodiment 1. FIG.

1. 1. Embodiment 1
The current detection device according to the first embodiment will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of an AC rotary machine 1 and a control device 10 according to the present embodiment. The current detection device is incorporated in the AC rotating machine 1 and the control device 10.

1-1. AC rotary machine 1
The AC rotating machine 1 includes a stator 18 and a rotor 14 arranged radially inside the stator 18. A first set of n-phase armature windings and a second set of n-phase armature windings (n is an integer of 3 or more) are wound around the iron core of the stator 18. In this embodiment, n is set to 3. That is, the stator 18 has three phases of armature windings Cu1, Cv1, and Cw1 of the first set of U1 phase, V1 phase, and W1 phase, and three phases of U2 phase, V2 phase, and W2 phase of the second set. Armature windings Cu2, Cv2, and Cw2 are provided. The three-phase armature windings of each set may be star-connected or delta-connected.

In this embodiment, as shown in the schematic diagram in FIG. 2, the second set of three-phase armature windings Cu2, Cv2, with respect to the positions of the first set of three-phase armature windings Cu1, Cv1 and Cw1. The phase difference Δθ at the electric angle of the position of Cw2 is set to Δθ = −π / 6 (−30 degrees). The electric angle is the mechanical angle of the rotor 14 multiplied by the number of pole pairs of the magnet.

The rotor 14 is provided with a magnet. In the present embodiment, the field winding 4 is wound around the iron core of the rotor 14, and the magnet of the rotor 14 is a magnet fielded by the field winding. Therefore, the AC rotating machine 1 is a field winding type synchronous rotating machine. The magnet of the rotor 14 may be a permanent magnet.

The rotor 14 is provided with a rotation sensor 15 that detects the rotation angle (rotation angle) of the rotor 14. The output signal of the rotation sensor 15 is input to the control device 10. As the rotation sensor 15, various sensors such as a Hall element, a resolver, or an encoder are used. The rotation sensor 15 may not be provided, and may be configured to estimate the rotation angle (pole position) based on the current information obtained by superimposing the harmonic component on the current command value described later (so-called). Sensorless method).

1-2. DC power supply 2
The DC power supply 2 outputs a DC voltage Vdc to the first set of inverters IN1, the second set of inverters IN2, and the converter 9. As the DC power supply 2, any device that outputs a DC voltage, such as a battery, a DC-DC converter, a diode rectifier, and a PWM rectifier, is used. A smoothing capacitor 3 is connected in parallel to the DC power supply 2.

1-3. The inverter IN1 of the first set of inverters performs power conversion between the DC power supply 2 and the three-phase armature windings of the first set. The second set of inverter IN2 performs power conversion between the DC power supply 2 and the second set of three-phase armature windings.

The first set of inverters IN1 is a series in which a switching element SP1 on the positive electrode side connected to the positive electrode side of the DC power supply 2 and a switching element SN1 on the negative electrode side connected to the negative electrode side of the DC power supply 2 are connected in series. Three circuits are provided corresponding to the armature windings of each of the three phases of the first set. The connection points of the two switching elements in each series circuit are connected to the first set of corresponding phase armature windings.

Specifically, in the first set of the U-phase series circuit, the switching element SPu1 on the positive electrode side of the U phase and the switching element SNu1 on the negative electrode side of the U phase are connected in series, and the connection point of the two switching elements is the first. It is connected to a set of U-phase armature windings Cu1. In the first set of V-phase series circuit, the switching element SPv1 on the positive electrode side of the V phase and the switching element SNv1 on the negative electrode side of the V phase are connected in series, and the connection point of the two switching elements is the first set of V-phase. It is connected to the armature winding Cv1 of. In the first set of W-phase series circuits, the switching element SPw1 on the positive electrode side of W and the switching element SNw1 on the negative electrode side of the W phase are connected in series, and the connection points of the two switching elements are of the first set of W-phase. It is connected to the armature winding Cw1.

The second set of inverters IN2 is a series in which a switching element SP2 on the positive electrode side connected to the positive electrode side of the DC power supply 2 and a switching element SN2 on the negative electrode side connected to the negative electrode side of the DC power supply 2 are connected in series. Three circuits are provided corresponding to the armature windings of the second set of three phases and each phase. The connection points of the two switching elements in each series circuit are connected to a second set of corresponding phase armature windings.

Specifically, in the second set of the U-phase series circuit, the switching element SPu2 on the positive electrode side of the U phase and the switching element SNu2 on the negative electrode side of the U phase are connected in series, and the connection point of the two switching elements is the second. It is connected to two sets of U-phase armature windings Cu2. In the second set of V-phase series circuits, the switching element SPv2 on the positive electrode side of the V phase and the switching element SNv2 on the negative electrode side of the V phase are connected in series, and the connection point of the two switching elements is the second set of V-phase. It is connected to the armature winding Cv2 of. In the second set of W-phase series circuits, the switching element SPw2 on the positive electrode side of W and the switching element SNw2 on the negative electrode side of the W phase are connected in series, and the connection points of the two switching elements are of the second set of W-phase. It is connected to the armature winding Cw2.

As the switching element of each set of inverters, an IGBT (Insulated Gate Bipolar Transistor) in which diodes are connected in anti-parallel connection, a bipolar transistor in which diodes are connected in anti-parallel connection, a MOSFET (Metal Oxide Semiconductor Field Effect Transistor), and the like are used. The gate terminal of each switching element is connected to the control device 10 via a gate drive circuit or the like. Therefore, each switching element is turned on or off by the switching signal output from the control device 10.

1-4. Magnetic sensor MS
A magnetic sensor MS for each phase of each set is provided to detect the current of the armature winding of each phase of each set. The magnetic sensor MS is a Hall element or the like. One magnetic sensor MS is provided for each armature winding of each phase of each set. The magnetic sensor MS of each phase of each set is arranged to face the connection line WR of each phase of each set that supplies a current to the armature winding of each phase of each set. Specifically, the magnetic sensor MS is arranged to face each of the six connection lines WR connecting each set of inverters and each set of three-phase armature windings. The first set of U1 phase magnetic sensors MSu1 are arranged to face each other on the first set of U1 phase connection lines WRu1, and the first set of V1 phase magnetic sensors MSv1 are arranged on the first set of V1 phase connection lines WRv1. The magnetic sensor MSw1 of the first set of W1 phases is arranged to face each other on the connection line WRw1 of the first set of W1 phases. The second set of U2 phase magnetic sensors MSu2 are arranged to face each other on the second set of U2 phase connection lines WRu2, and the second set of V2 phase magnetic sensors MSv2 are arranged on the second set of V2 phase connection lines WRv2. The second set of W2 phase magnetic sensors MSw2 are arranged to face each other on the second set of W2 phase connection lines WRw2. The output signal of each magnetic sensor MS is input to the control device 10.

1-5. Converter 9
The converter 9 has a switching element and performs power conversion between the DC power supply 2 and the field winding 4. In the present embodiment, the converter 9 is a series in which the switching element SP on the positive electrode side connected to the positive electrode side of the DC power supply 2 and the switching element SN on the negative electrode side connected to the negative electrode side of the DC power supply 2 are connected in series. It is an H-bridge circuit with two circuits. The connection point between the positive electrode side switching element SP1 and the negative electrode side switching element SN1 in the first series circuit 28 is connected to one end of the field winding 4, and the positive electrode side switching element SP2 in the second series circuit 29. The connection point between the negative electrode side and the switching element SN2 on the negative electrode side is connected to the other end of the field winding 4.

As the switching element of the converter 9, an IGBT in which diodes are connected in antiparallel, a bipolar transistor in which diodes are connected in antiparallel, a MOSFET, and the like are used. The gate terminal of each switching element is connected to the control device 10 via a gate drive circuit or the like. Therefore, each switching element is turned on or off by the switching signal output from the control device 10.

The converter 9 may have other configurations such as replacing the switching element SN1 on the negative electrode side of the first series circuit 28 with a diode or replacing the switching element SP2 on the positive electrode side of the second series circuit 29 with a diode. good.

The field current sensor 6 is a current detection circuit that detects the field current If, which is the current flowing through the field winding 4. In the present embodiment, the field current sensor 6 is provided on the electric wire between the connection point of the first series circuit 28 and one end of the field winding 4. The field current sensor 6 may be provided at another location where the field current If can be detected. The output signal of the field current sensor 6 is input to the control device 10. The field current sensor 6 is a current sensor such as a Hall element and a shunt resistor.

1-6. Control device 10
The control device 10 controls the AC rotary machine 1 via the inverters IN1 and IN2 of the first set and the second set, and the converter 9. As shown in FIG. 3, the control device 10 includes functional units such as a rotation detection unit 31, an armature current detection unit 32, an armature current control unit 33, a field current detection unit 34, and a field current control unit 35. I have. Each function of the control device 10 is realized by a processing circuit provided in the control device 10. Specifically, as shown in FIG. 12, the control device 10 includes an arithmetic processing unit 90 (computer) such as a CPU (Central Processing Unit), a storage device 91 for exchanging data with the arithmetic processing unit 90, as a processing circuit. The arithmetic processing unit 90 includes an input circuit 92 for inputting an external signal, an output circuit 93 for outputting a signal from the arithmetic processing unit 90 to the outside, a communication circuit 94 for data communication with the external device, and the like.

The arithmetic processing device 90 is provided with an ASIC (Application Specific Integrated Circuit), an IC (Integrated Circuit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), various logic circuits, various signal processing circuits, and the like. You may. Further, as the arithmetic processing unit 90, a plurality of the same type or different types may be provided, and each processing may be shared and executed. As the storage device 91, a RAM (Random Access Memory) configured to be able to read and write data from the arithmetic processing unit 90, a ROM (Read Only Memory) configured to be able to read data from the arithmetic processing unit 90, and the like are used. It is prepared. The input circuit 92 is connected to various sensors such as a rotation sensor 15, a magnetic sensor MS for each phase of each set, and a field current sensor 6, and A / D conversion in which the output signals of these sensors are input to the arithmetic processing device 90. Equipped with vessels, etc. The output circuit 93 is connected to an electric load such as a gate drive circuit that drives the switching elements of the first and second sets of inverters IN1 and IN2 and the converter 9 on and off, and a control signal from the arithmetic processing device 90 is connected to these electric loads. It is equipped with a drive circuit that outputs. The communication circuit 94 communicates with an external device.

Then, in each function of the control units 31 to 35 included in the control device 10, the arithmetic processing unit 90 executes software (program) stored in the storage device 91 such as a ROM, and the storage device 91 and the input circuit 92. , And by cooperating with other hardware of the control device 10 such as the output circuit 93. Various setting data used by the control units 31 to 35 and the like are stored in a storage device 91 such as a ROM as a part of software (program). Hereinafter, each function of the control device 10 will be described in detail.

<Rotation detection unit 31>
The rotation detection unit 31 detects the rotor magnetic pole position θ (rotor rotation angle θ) and the rotation angular velocity ω at the electric angle. In the present embodiment, the rotation detection unit 31 detects the magnetic pole position θ (rotation angle θ) and the rotation angular velocity ω at the electric angle based on the output signal of the rotation sensor 15. The magnetic pole position is set in the direction of the north pole of the electromagnet provided in the rotor. In the present embodiment, the magnetic pole position θ (rotation angle θ) is the position (angle) of the magnetic pole (N pole) at the electric angle with respect to the armature winding of the U1 phase of the first set. From the phase difference π / 6 between the first set of armature windings and the second set of armature windings shown in FIG. 2, the electric angle is based on the second set of U2 phase armature windings. The position (angle) of the magnetic pole (N pole) of is θ−π / 6.

The rotation detection unit 31 is configured to estimate the rotation angle (pole position) based on the current information obtained by superimposing the harmonic component on the current command value without using the rotation sensor. It is also good (so-called sensorless method).

<Armature current detection unit 32>
The armature current detection unit 32 detects the armature winding current flowing in the armature winding of each phase of each set based on the output signal of the magnetic sensor MS of each phase of each set. Specifically, the armature current detection unit 32 detects the armature winding current iu1s of the first set of U1 phases based on the output signal of the magnetic sensor MSu1 of the first set of U1 phases, and the first set. Based on the output signal of the V1 phase magnetic sensor MSv1 of the above, the armature winding current iv1s of the first set of V1 phases is detected, and the first set is based on the output signal of the W1 phase magnetic sensor MSw1. The set of W1 phase armature winding currents iw1s is detected. Further, the armature current detection unit 32 detects the armature winding current iu2s of the second set of U2 phases based on the output signal of the magnetic sensor MSu2 of the second set of U2 phases, and the armature current detection unit 32 detects the armature winding current iu2s of the second set of V2 phases. 2nd set of V2 phase armature winding current iv2s is detected based on the output signal of the magnetic sensor MSv2 of the 2nd set, and 2nd set of W2 is detected based on the output signal of the 2nd set of W2 phase magnetic sensor MSw2. The phase armature winding current iw2s is detected.

<Armature current control unit 33>
The armature current control unit 33 uses vector control such as maximum torque current control, weak magnetic flux control, and Id = 0 control, and is based on the torque command value, rotational angular velocity ω, etc., of the first set of d-axis and q-axis. The current command values id1c and iq1c, and the second set of d-axis and q-axis current command values id2c and iq2c are calculated.

The d-axis is set in the direction of the magnetic pole (N pole) of the magnet, and the q-axis is set in the direction 90 degrees ahead of the d-axis in terms of electrical angle.

As shown in the following equation, the armature current control unit 33 converts the current detection values iu1s, iv1s, and iw1s of the first set of three-phase armature windings into three-phase two-phase conversion and iw1s based on the magnetic pole position θ. Rotational coordinate conversion is performed to convert the current detection value id1s on the d-axis and the current detection value iq1s on the q-axis of the first set.

As shown in the following equation, the armature current control unit 33 converts the current detection values iu2s, iv2s, and iw2s of the second set of three-phase armature windings into three-phase two-phase conversion and iw2s based on the magnetic pole position θ. Rotational coordinate conversion is performed to convert the current detection value id2s on the d-axis and the current detection value iq2s on the q-axis of the second set.

As described above, the magnetic pole position with respect to the second set of U2 phase armature windings is θ−π / 6, so the coordinate transformation of equation (1) and the coordinate transformation of equation (2) A phase difference π / 6 is provided between them.

The armature current control unit 33 controls the currents of the first set of d-axis and q-axis so that the current detection values id1s and iq1s approach the current command values id1c and iq1c of the first set of d-axis and q-axis by PI control or the like. , The voltage command values Vd1c and Vq1c of the first set of d-axis and q-axis are calculated. Then, as shown in the following equation, the armature current control unit 33 converts the voltage command values Vd1c and Vq1c of the first set of d-axis and q-axis into fixed coordinates and two-phase three-phase based on the magnetic pole position θ. The conversion is performed and converted into the voltage command values Vu1c, Vv1c, and Vw1c of the first set of three phases.

The armature current control unit 33 is subjected to PI control or the like so that the current detection values id2s and iq2s of the second set of d-axis and q-axis approach the current command values id2c and iq2c of the second set of d-axis and q-axis. , The voltage command values Vd2c and Vq2c of the second set of d-axis and q-axis are calculated. Then, as shown in the following equation, the armature current control unit 33 converts the voltage command values Vd2c and Vq2c of the second set of d-axis and q-axis into fixed coordinates and two-phase three-phase based on the magnetic pole position θ. The conversion is performed and converted into the voltage command values Vu2c, Vv2c, and Vw2c of the second set of three phases.

Similar to the equation (1) and the equation (2), a phase difference π / 6 is provided between the coordinate transformation of the equation (3) and the coordinate transformation of the equation (4). The armature current control unit 33 performs known modulation such as space vector modulation and two-phase modulation on the voltage command values of the three phases of the first set and the second set in order to improve the voltage utilization rate. May be added.

The armature current control unit 33 controls on / off of a plurality of switching elements of the first set of inverter IN1 by PWM control (Pulse Width Modulation) based on the voltage command values Vu1c, Vv1c, and Vw1c of the first set of three phases. .. Further, the armature current control unit 33 controls on / off of a plurality of switching elements of the second set of inverter IN2 by PWM control based on the voltage command values Vu2c, Vv2c, and Vw2c of the second set of three phases. As the PWM control, a known carrier wave comparison PWM or space vector PWM is used.

<Control of field current>
The field current detection unit 34 detects the field current Ifs, which is the current flowing through the field winding 4, based on the output signal of the field current sensor 6. The field current control unit 35 sets the field current command value Ifc based on the torque command value and the like. The field current control unit 35 calculates the field voltage command value Vf by PI control or the like so that the field current detection value Ifs approaches the field current command value Ifc. Then, the field current control unit 35 controls the on / off of the plurality of switching elements of the converter 9 by PWM control based on the field voltage command value Vf.

1-7. Arrangement of Magnetic Sensor MS for Reducing Current Detection Error Due to Rotor Magnetic Flux FIG. 4 is a schematic view showing the arrangement position of the magnetic sensor MS for each phase of each set as viewed in the axial direction. The magnetic sensor MS of each phase of each set is arranged at a position where the magnetic fluxes radiated radially from the rotor 14 intersect.

In the present embodiment, the magnetic flux direction and the magnetic flux density of the rotor intersecting each magnetic sensor MS do not change according to the rotation of the rotor. In other words, the magnetic flux density radially radiated from the portion of the rotor (rotating shaft 14a in this example) arranged radially inside each magnetic sensor MS does not change in the circumferential direction. The magnetic flux direction and magnetic flux density of the rotor intersecting each magnetic sensor MS depend on the rotation of the rotor due to the influence of the magnetic flux radiated from the magnetic poles of the N pole and the S pole alternately arranged in the circumferential direction. It may vary slightly (eg, within ± 10%).

<Randel type rotor>
In the present embodiment, the rotor 14 is a Randell type (also referred to as a claw pole type) rotor. The rotation shaft 14a of the rotor 14 is arranged inside the magnetic sensor MS of each phase of each set in the radial direction. The portion of the rotation shaft 14a arranged radially inside each magnetic sensor MS becomes an N pole or an S pole. Then, the magnetic flux radiating radially from the rotation shaft 14a intersects each magnetic sensor MS.

FIG. 5 shows a perspective view of the Randell type rotor, and FIG. 6 shows a cross-sectional view of the AC rotary machine 1. The rotor 14 has a columnar or cylindrical rotating shaft 14a, a field iron core 14b that rotates integrally with the rotating shaft 14a, and a field winding 14c wound around the field iron core 14b. The field iron core 14b extends radially outward from the end of the cylindrical central portion 14b1 fitted to the outer peripheral surface of the rotating shaft 14a and the axial one-side X1 of the central portion 14b1, and then the central portion. A plurality of first claw portions 14b2 extending radially outside of 14b1 to the other side X2 in the axial direction, and extending outward in the radial direction from the end portion of the other side X2 in the axial direction of the central portion 14b1 and then extending outward in the central portion 14b1. It has a plurality of second claw portions 14b3 extending radially outside of the above to one side X1 in the axial direction. The first claw portion 14b2 and the second claw portion 14b3 are alternately arranged in the circumferential direction, and have different magnetic poles from each other. For example, the first claw portion 14b2 and the second claw portion 14b3 are provided with 6 or 8 pieces, respectively, and the number of pole pairs is 6 or 8.

The field winding 14c is wound around the rotating shaft 14a and the outer peripheral portion of the central portion 14b1 of the field iron core in a concentric circle centered on the axial center C. An axial magnetic flux is generated inside the field winding 14c in the radial direction, and the portion of the rotor on one side X1 in the axial direction and the portion on the other side X2 in the axial direction become magnetic poles different from each other. In order to assist the field winding 14c, permanent magnets may be provided on the outer peripheral portion of the rotating shaft 14a and the central portion 14b1 of the field iron core. Further, in order to reduce the leakage of the magnetic flux between the magnetic poles, a permanent magnet magnetized in the circumferential direction may be arranged between the first claw portion 14b2 and the second claw portion 14b3.

Therefore, in the Landel-type rotor in which the field winding 14c is wound concentrically around the axial center C, the portion of one side X1 in the axial direction of the rotor and the portion of one side X1 in the axial direction of the rotor. Are different magnetic poles from each other. Hereinafter, a case where the portion of one side X1 in the axial direction of the rotor is the N pole and the portion of the other side X2 in the axial direction of the rotor is the S pole will be described. The N pole and the S pole may be interchanged, and one side X1 in the axial direction and the other side X2 in the axial direction may be interchanged.

The portion of the rotating shaft 14a protruding from the field core 14b to one side X1 in the axial direction and the portion of the field core 14b including the first claw portion 14b2 on one side X1 in the axial direction are N poles. The portion of the rotating shaft 14a protruding from the field core 14b to the other side X2 in the axial direction and the portion of the field iron core 14b including the second claw portion 14b3 on the other side X2 in the axial direction are the S poles.

<Arrangement of each magnetic sensor>
The magnetic sensor MS of each phase of each set is arranged on one side X1 in the axial direction of the rotor, and magnetic fluxes radiated radially from the portion of one side X1 in the axial direction of the rotor intersect. The magnetic flux intersecting the magnetic sensor MS may include an axial component in addition to a radial component.

As shown in FIG. 6, the first set and the second set of inverters IN1 and IN2 are arranged on one side X1 in the axial direction of the stator 18. The connection line WR of each phase of each set extends from the armature windings of the first set and the second set to one side X1 in the axial direction, and is connected to the inverters IN1 and IN2 of the first set and the second set. There is. The connection line WR of each phase of each set is arranged radially outside the portion of the rotation shaft 14a of one side X1 in the axial direction, and each set is arranged to face the connection line WR of each phase of each set. The magnetic sensor MS of each phase of the above is arranged on the outer side in the radial direction of the portion of the rotation shaft 14a of the one side X1 in the axial direction.

The magnetic flux radiated radially from the portion of the rotating shaft 14a on one side X1 in the axial direction intersects the magnetic sensor MS of each phase of each set. In the magnetic sensor MS of each phase of each set, magnetic fluxes radiated radially from the end of one side X1 in the axial direction of the field iron core 14b may intersect.

In the present embodiment, as shown in FIG. 4, the first set of magnetic sensor MSs and the second set of magnetic sensor MSs are arranged alternately in the circumferential direction at equal angular intervals. MSu1, MSu2, MSv1, MSv2, MSw1, and MSw2 are arranged in this order on the same circle centered on the axis C at equal intervals of π / 3 (60 degrees) in the machine angle in the circumferential direction. The order of the magnetic sensors MS in the circumferential direction may be any order. Further, the magnetic sensor MSs do not have to be arranged at equal angular intervals in the circumferential direction. By arranging the magnetic sensor MSs at equal angular intervals in the circumferential direction, it is possible to reduce the detection error of the magnetic sensor MS due to the magnetic flux generated by the current of the other connection line WR in which the magnetic sensor MSs are not arranged facing each other. If a part of each magnetic sensor MS is on the same circle, it can be treated as a category of error.

Each magnetic sensor MS (sensor element) detects a component of the magnetic flux density of the magnetic flux detection direction DS of the magnetic flux intersecting the sensor element, and outputs a signal corresponding to the detected magnetic flux density. The magnetic flux detection direction DS is a specific direction according to the arrangement direction of the sensor element. As shown in the schematic view in the extending direction of the connection line WR in FIG. 7, the magnetic flux detection direction DS of each magnetic sensor MS (sensor element) is parallel to the direction of the magnetic flux generated by the current flowing through each connection line WR. It is arranged so as to be. That is, the magnetic flux detection direction DS of each magnetic sensor MS is arranged so as to be parallel to the circumferential direction about each connection line WR. As shown in FIG. 8, each magnetic sensor MS may be provided with a magnetic collecting core 20.

In the example of FIG. 4, the portion of each connection line WR in which each magnetic sensor MS is arranged to face each other extends substantially in the radial direction. Each magnetic sensor MS (sensor element) is arranged on the other side X2 in the axial direction of the portion of the connecting line WR extending in the radial direction so as to face the connecting line WR.

Each magnetic sensor MS detects the magnetic flux density generated in proportion to the current of the opposing connection line WR. When the magnetic flux detection direction DS of the magnetic sensor MS is orthogonal to the magnetic flux of the rotor in the radial direction intersecting the sensor element, the magnetic flux density component of the magnetic flux detection direction DS of the rotor magnetic flux does not occur, so that the current due to the magnetic flux of the rotor does not occur. There is no detection error. However, the magnetic flux detection direction DS of the magnetic sensor MS is tilted with respect to the radial orthogonal plane Por, which is a plane orthogonal to the radial direction passing through the sensor element, without being orthogonal to the magnetic flux of the radial rotor intersecting the sensor element. If so, a component of the magnetic flux density of the magnetic flux detection direction DS of the rotor magnetic flux is generated according to the tilt angle θt, so that a current detection error due to the magnetic flux of the rotor occurs.

Here, θt11 is defined as the tilt angle of the magnetic flux detection direction DS11 of the magnetic sensor MSu1 with respect to the radial orthogonal plane Por11 which is the direction orthogonal to the radial direction passing through the center of the magnetic sensor MSu1 of the first set of U1 phases, and θt21 is defined as , The tilt angle of the magnetic flux detection direction DS21 of the magnetic sensor MSv1 with respect to the radial orthogonal plane Por21 which is the direction orthogonal to the radial direction passing through the center of the magnetic sensor MSv1 of the first set of V1 phases, and θt31 is set to the first set. The tilt angle of the magnetic flux detection direction DS31 of the magnetic sensor MSw1 with respect to the radial orthogonal plane Por31 which is the direction orthogonal to the radial direction passing through the center of the W1 phase magnetic sensor MSw1. θt12 is the tilt angle of the magnetic flux detection direction DS12 of the magnetic sensor MSu2 with respect to the radial orthogonal plane Por12 which is the direction orthogonal to the radial direction passing through the center of the magnetic sensor MSu2 of the second set of U2 phases, and θt22 is the second. Let θt32 be the tilt angle of the magnetic flux detection direction DS22 of the magnetic sensor MSv2 with respect to the radial orthogonal plane Por22 which is the direction orthogonal to the radial direction passing through the center of the set of V2 phase magnetic sensors MSv2, and set θt32 to be the W2 phase of the second set. It is the tilt angle of the magnetic flux detection direction DS32 of the magnetic sensor MSw2 with respect to the radial orthogonal plane Por32 which is a direction orthogonal to the radial direction passing through the center of the magnetic sensor MSw2. In the present embodiment, the magnetic flux detection direction DS of each magnetic sensor MS is orthogonal to the axial direction, and the inclination angle θt of each magnetic sensor is a circle centered on the axis C and passing through each magnetic sensor MS. It is the inclination angle with respect to the tangential direction of. Here, the direction of the current flowing through the connection line WR will be described in the case of the outer diameter direction in all the phases, but it may be the inner diameter direction in some or all the phases. In that case, the same idea can be obtained by setting the magnetic flux detection direction DS in the opposite direction and setting the inclination angle θt accordingly.

As shown in FIG. 9, the portion of each connection line WR in which each magnetic sensor MS is arranged to face each other may extend in the axial direction. Then, the magnetic sensor MS (sensor element) may be arranged so as to face the connecting line WR inside in the radial direction of the portion of the connecting line WR extending in the axial direction. Even in this case, if the magnetic flux detection direction DS of the magnetic sensor MS is tilted with respect to the radial orthogonal plane Por, which is a plane orthogonal to the radial direction passing through the sensor element, the magnetic flux of the rotor is increased according to the tilt angle θt. Since the component of the magnetic flux density in the magnetic flux detection direction DS is generated, a current detection error due to the magnetic flux of the rotor occurs.

<Effect of current detection error>
Considering the current detection error due to the magnetic flux of the rotor, the current detection values iu1s to iw2s of each phase of each set detected by the magnetic sensor MS of each phase of each set are expressed by the following equations.

Here, iu1 is a true current value flowing through the armature winding of the first set of U1 phases, δu1 is a detection error component of the current of the first set of U1 phases due to the magnetic flux of the rotor, and iv1 is. , Δv1 is the detection error component of the current of the first set of V1 phase due to the magnetic flux of the rotor, and iw1 is the detection error component of the current of the first set of V1. It is a true current value flowing through the armature winding of the W1 phase, and δw1 is a detection error component of the current of the first set of V1 phases due to the magnetic flux of the rotor. iu2 is the true current value flowing through the second set of U2 phase armature windings, δu2 is the detection error component of the second set of U2 phase currents due to the magnetic flux of the rotor, and iv2 is the second set. The true current value flowing through the armature winding of the V2 phase of the set, δv2 is the detection error component of the current of the V2 phase of the second set due to the magnetic flux of the rotor, and iw2 is the W2 phase of the second set. It is a true current value flowing through the armature winding, and δw2 is a detection error component of the current of the second set V2 phase due to the magnetic flux of the rotor. I is the magnitude of the current vector of each set, and β is the phase of the current vector with respect to the q-axis of each set. From the phase difference π / 6 between the first set of armature windings and the second set of armature windings shown in FIG. 2, the true current value of the second set of three phases is the first set of three phases. It is delayed by the phase difference π / 6 with respect to the true current value of.

<Relationship between d-axis and q-axis sum current and output torque>
The output torque T of the AC rotating machine can be expressed by the following equation. Pm is the logarithm of the poles, ψ is the interlinkage magnetic flux of the magnet, Ld is the inductance of the d-axis, and Lq is the inductance of the q-axis. Here, the true difference current of the d-axis and the true difference current of the q-axis (id1) between the sets are compared with the true sum current of the d-axis and the true sum current of the q-axis (id1 + id2, iq1 + iq2). -Using the fact that id2 and iq1-iq2) are minute, the output torque T is approximated to the formula for calculating the output torque T by the true sum current of the d-axis and the true sum current of the q-axis between the sets.

From the approximate expression of the output torque T of the equation (6), the output torque is reduced by reducing the detection error component included in the true sum current of the d-axis and the true sum current of the q-axis (id1 + id2, iq1 + iq2) between the sets. The accuracy of the current can be improved and the ripple component contained in the output torque can be reduced.

<Detection error of sum current of d-axis and q-axis due to magnetic flux of rotor>
The sum current of the first set of d-axis current detection values Id1s and the second set of d-axis current detection values Id2s obtained by substituting the equation (5) into the equations (1) and (2) and performing coordinate conversion. , The sum current of the current detection value Iq1s of the first set of q-axis and the current detection value Iq2s of the second set of q-axis is given by the equations (7) and (8).

Here, the first term on the right side of the equation (7) is the true sum current on the d-axis, and the first term on the right side of the equation (8) is the true sum current on the q-axis. Therefore, the second and third terms on the right side of the equation (7) are the detection error components of the sum current of the d-axis due to the magnetic flux of the rotor, and the second and third terms on the right side of the equation (8) are. It is a detection error component of the sum current of the q-axis due to the magnetic flux of the rotor.

When the current feedback control is performed based on the current detection values of the d-axis and the q-axis including the error, the true current values of the d-axis and the q-axis deviate from the current command values of the d-axis and the q-axis by the error. As shown in the approximate equation of the equation (6), the output torque T changes according to the sum current of the d-axis and the sum current of the q-axis. Therefore, the actual output torque is the detection error of the sum current of the d-axis. Detection error of the component and the sum current of the q-axis Depending on the component, the output torque deviates from the target output torque corresponding to the current command value of the d-axis and the q-axis. The detection error component of the sum current of the d-axis of the second and third terms on the right side of the equation (7), and the detection error component of the sum current of the d-axis of the second and third terms on the right side of the equation (8). Is a vibration component that vibrates according to the magnetic pole position θ, so that torque ripple occurs in the output torque T due to a detection error.

The detection error component δ of the current of each phase of each set due to the magnetic flux of the rotor is the magnetic flux detection direction DS of the magnetic sensor of each set of each phase with respect to the radial orthogonal plane Por which is a plane orthogonal to the radial direction passing through each magnetic sensor MS. It is expressed by the following equation using the inclination angle θt of.

Here, Br is the magnetic flux density of the magnetic flux in the radial direction of the rotor passing through each magnetic sensor, and in the present embodiment, each magnetic sensor is arranged on the same circle centered on the axis C. , The same value for each magnetic sensor. By Br × sinθt, the detection component Bs of the rotor magnetic flux density, which is the component of the magnetic flux density of the rotor detected by each magnetic sensor, is calculated. Kbi is a conversion coefficient from the detection component Bs of the rotor magnetic flux density to the current detection value. The tilt angle θtk1 (k is an integer of 1 or more) is the tilt angle of the k-phase of the first set, and instead of the U1 phase, the V1 phase, and the W1 phase, the first phase, the second phase, and the third phase. Is used. The tilt angle θth2 (h is an integer of 1 or more) is the tilt angle of the second set of h phases, and instead of the U2 phase, V2 phase, and W2 phase, the first phase, the second phase, and the third phase. Is used. Similarly, Bsk1 is a detection component of the first set of the k-phase, and Bsh2 is a detection component of the second set of the h-phase.

Substituting the equation (9) into the equations (7) and (8), the detected values of the sum currents on the d-axis and the q-axis become the equations (10) and (11).

<Expression of sum current detection error using ripple components R1 and R2>
Here, the first set of ripple components R1 and the second set of ripple components R2 are defined by the formula (12).

Here, the magnetic pole position θ is the phase (angle) of the magnetic poles (N poles) of the rotor at the electric angle with respect to the position of the armature winding of the first set of U1 phases, as described above. In the first equation of the equation (12), the phase θ of the sine function of the first term on the right side is the phase of the magnetic pole (N pole) at the electric angle with respect to the position of the armature winding Cu1 of the first set of U1 phases (N pole). Angle) θe11, and the phase (θ-2π / 3) of the sine function of the second term on the right side is the phase θe21 of the magnetic pole with respect to the armature winding Cv1 of the first set of V1 phases, and the third term on the right side. The phase (θ + 2π / 3) of the sine function of is the phase θe31 of the magnetic pole with respect to the armature winding Cw1 of the first set of W1 phases. In the second equation of the equation (12), the phase (θ−π / 6) of the sine function of the first term on the right side is the magnetic pole at the electric angle with respect to the position of the armature winding Cu2 of the second set of U2 phases. The phase θe12, and the phase (θ-5π / 6) of the sine function of the second term on the right side is the phase θe22 of the magnetic pole with respect to the armature winding Cv2 of the second set of V2 phases, and the phase of the third term on the right side. The phase (θ + π / 2) of the sine function is the phase θe32 of the magnetic pole with respect to the armature winding Cw2 of the second set of W2 phases.

Therefore, if the equation (12) is generalized and expressed, the equation (13) is obtained.

Here, θek1 is the phase of the magnetic pole of the rotor at the electric angle with respect to the position of the armature winding of the first set of the k-phase, and from the magnetic pole position θ with respect to the armature winding Cu1 of the first set of U1 phases. , The phase obtained by subtracting the phase of the first set of k-phase armature windings with respect to the first set of U1 phase armature windings Cu1. Bsk1 is a detection component of the rotor magnetic flux density detected by the magnetic sensor of the first set of the k-phase. θeh2 is the phase of the magnetic pole of the rotor at the electric angle with respect to the position of the armature winding of the second set of h-phase, and is the first from the magnetic pole position θ with respect to the armature winding Cu1 of the first set of U1 phase. The phase is obtained by subtracting the phase of the second set of h-phase armature windings with respect to the set of U1 phase armature windings Cu1. Bsh2 is a detection component of the rotor magnetic flux density detected by the second set of h-phase magnetic sensors.

<Reduction of sum current detection error by mutual cancellation of ripple components R1 and R2>
When the equation (10) is expressed using the equation (12), as shown in the equation (14), the second term on the right side of the equation (10) indicates the phase of the magnetic pole position θ of the ripple component R1 of the first set. , Π / 2 advanced by a coefficient, and the third term is for the phase of the magnetic pole position θ of the second set of ripple components R2 advanced by π / 2. And multiplied by the coefficient. When the equation (11) is expressed using the equation (12), as shown in the equation (15), the second term on the right side of the equation (11) sets the phase of the magnetic pole position θ of the ripple component R1 of the first set. , The one advanced by π is multiplied by a coefficient, and the third term is the phase of the magnetic pole position θ of the ripple component R2 of the second set multiplied by a coefficient with respect to the one advanced by π. It is a coefficient.

<Setting of tilt angle θt for mutual cancellation of ripple components R1 and R2>
From equations (14) and (15), if the positive and negative signs of the first set of ripple components R1 and the positive and negative signs of the second set of ripple components R2 are different from each other, they can cancel each other out. It can be seen that the detection error of the sum current of the axis and the q axis can be reduced. From the equations (12) and (13), the values of R1 and R2 change depending on the detection component Bs of the rotor magnetic flux density of each phase of each set, and the value of Bs is from the equation (9) of each of the sets. It changes depending on the tilt angle θt of the magnetic flux detection direction DS of the phase magnetic sensor.

Therefore, in the present embodiment, each phase of each set with respect to the radial plane Por so that the positive and negative signs of the first set of ripple components R1 and the positive and negative signs of the second set of ripple components R2 are different from each other. The tilt angle θt of the magnetic flux detection direction DS of the magnetic sensor is set.

According to this configuration, the ripple component R1 of the first set and the ripple component R2 of the second set cancel each other out, and the detection error of the sum current of the d-axis and the q-axis due to the magnetic flux of the rotor can be reduced. Then, as described using the equation (6), the control accuracy of the output torque can be improved by reducing the detection error of the sum current of the d-axis and the q-axis.

<Example of reducing sum current detection error>
As shown in the equation (16), if the inclination angle θt of each magnetic sensor is set, the equation (17) holds. Therefore, the detected values of the sum currents of the d-axis and the q-axis are the equations (18) and (19). ) Can be expressed. In this example, the combinations in which the tilt angle θt and the current detection error component δ are set to positive and negative inversion values are the U2 phase tilt angle θt12, the U1 phase tilt angle θt11, and the V2 phase tilt angle θt22. The inclination angle θt21 of the V1 phase, the inclination angle θt32 of the W2 phase, and the inclination angle θt31 of the W1 phase. As can be seen from FIG. 2, these combinations are a combination of the first set of phases and the second set of phases in which the phase difference (current phase difference) of the armature windings is the smallest between the sets. The phase difference is π / 6.

Comparing equations (18) and (19) with equations (7) and (8), the amplitude of the detection error component of the sum current of the d-axis and q-axis of the first set of armature windings is 2 sin. (Π / 12) = (√6-√2) / 2 ≈ 0.517 times reduction. π / 12 is half of the phase difference π / 6 of the armature winding between the sets.

<Comparative example in which the detection error of the sum current deteriorates>
On the contrary, a comparative example in which the amplitude of the detection error component of the sum current of the d-axis and the q-axis increases is shown. As shown in the equation (20), if the inclination angle θt of each magnetic sensor is set, the equation (21) holds. Therefore, the detected values of the sum currents of the d-axis and the q-axis are the equations (22) and (23). ) Can be expressed. In this example, the combinations in which the tilt angle θt and the current detection error component δ are set to positive and negative inversion values are the U2 phase tilt angle θt12, the V1 phase tilt angle θt21, and the V2 phase tilt angle θt22. The tilt angle θt31 of the W1 phase, the tilt angle θt32 of the W2 phase, and the tilt angle θt11 of the U1 phase. As can be seen from FIG. 2, these combinations are a combination of the first set of phases and the second set of phases in which the phase difference (current phase difference) of the armature windings is the second smallest between the sets. The phase difference is π / 2.

Comparing equations (22) and (23) with equations (7) and (8), the amplitude of the detection error component of the sum current of the d-axis and q-axis of the first set of armature windings is 2 sin. (5π / 12) = (√6 + √2) / 2≈1.931 times. 5π / 12 is half the sum of the phase difference π / 6 of the armature winding between the sets and the phase difference 2π / 3 of the armature winding between the phases.

<Setting method to reduce the detection error of sum current>
From the above two examples, the phase difference of the current (or the phase difference at the electric angle of the position of the armature winding) between the first set of armature windings and the second set of armature windings In each combination of the first set of phases and the second set of phases, which are the smallest, the positive and negative signs of the detection component Bs of the rotor magnetic flux density by the magnetic sensor of the first set of phases and the magnetism of the second set of phases. It is preferable that the tilt angle θt of the magnetic sensor of each phase of each set is set so that the positive and negative signs of the detection component Bs of the rotor magnetic flux density by the sensor are different from each other.

As shown in the equation (9), the detection component Bs of the rotor magnetic flux density is proportional to the detection error component δ of the current due to the magnetic flux of the rotor. Further, if the positive and negative signs of the tilt angle θt of the magnetic sensor are different, the positive and negative signs of the detection component Bs of the rotor magnetic flux density can be different.

According to this configuration, the detection error component δ of the first phase current and the detection error component δ of the second phase current, which have the smallest phase difference between the sets in the state of being converted into the d-axis current and the q-axis current. The positive and negative signs are different from each other, and they cancel each other out. Therefore, the detection error of the sum current of the d-axis and the q-axis can be reduced, and the control accuracy of the output torque can be improved.

Further, as in the above-mentioned example, in each of the combinations, the absolute value of the rotor magnetic flux density detection component Bs by the magnetic sensor of the first set of phases and the detection component Bs of the rotor magnetic flux density by the magnetic sensor of the second set of phases. It is preferable that the tilt angle θt of the magnetic sensor of each phase of each set is set so that the absolute values of are the same as each other.

According to this configuration, the detection error component δ of the first phase current and the detection error component δ of the second phase current, which have the smallest phase difference between the sets in the state of being converted into the d-axis current and the q-axis current. It is possible to enhance the effect of canceling each other out.

In the present embodiment, the phase difference Δθ of the current of the second set of armature windings with respect to the current of the armature windings of the first set (the same applies to the phase difference at the electric angle of the winding position) is Δθ = −. It is π / 6. However, if the phase difference Δθ of the current of the second set of armature windings with respect to the current of the armature windings of the first set (the same applies to the phase difference at the electric angle of the winding position) is within the range of the following equation. , The detection error component δ of the first phase current and the detection error component δ of the second phase current, which have the smallest phase difference between the sets in the state of being converted into the d-axis current and the q-axis current, cancel each other out. The effect can be obtained.

The phase difference Δθ of the current of the second set of armature windings with respect to the current of the armature winding of the first set (the same applies to the phase difference at the electric angle of the winding position) cancels out within the range of the following equation. The matching effect is enhanced, which is more suitable.

<When phase difference Δθ = 0>
As shown in FIG. 10, the position of the position of the second set of three-phase armature windings Cu2, Cv2, Cw2 with respect to the position of the first set of three-phase armature windings Cu1, Cv1 and Cw1 in terms of electrical angle. The case where the phase difference Δθ (the same applies to the phase difference of the current) is set to 0 (Δθ = 0) will be described.

In this case, the detected value of the sum current of the d-axis and the q-axis can be expressed by the equations (26) and (27).

As in equations (26) and (27), the first set of phases and the first set in which the phase difference of the current between the first set of armature windings and the second set of armature windings becomes zero. In each of the combinations with the two sets of phases, positive and negative are positive and negative between the detection component Bs of the rotor magnetic flux density by the magnetic sensor of the first set of phases and the detection component Bs of the rotor magnetic flux density by the magnetic sensor of the second set of phases. It is most preferable that the tilt angle θt of the magnetic sensor of each phase of each set is set so that the symbols of the two are different from each other and the absolute values are the same.

With this setting, as shown in the following equation, the detection error component δ of the first set of current and the detection error component δ of the second set of current can be completely canceled out, and the d-axis and q-axis can be set. The component of the detection error of the sum current becomes 0. Therefore, the control accuracy of the output torque can be maximized.

At this time, as shown in the following equation, the total value of the first set of ripple components R1 and the second set of ripple components R2 becomes 0.

<Abnormality judgment>
Ideally, if the equations (16) and (17) are set, the current detection error components δ of each phase of each set are completely mutually complete as shown in the following equations from the equation (5). The sum of the current detection values of the first set of three phases and the sum of the current detection values of the second set of three phases becomes 0.

On the other hand, when the magnetic sensors of each phase of each set are arranged so that the detection error components δ of the current of each phase of each set do not completely cancel each other, the total value becomes a predetermined value offset from 0. ..

Therefore, as shown in the following equation, the armature current detection unit 32 uses the sum of the current detection values of the first set of three-phase armature windings and the current detection value of the second set of three-phase armature windings. When the total value of the sum and the sum of the above exceeds a preset determination range, it is determined that an abnormality has occurred.

The armature current detection unit 32 determines that the equation (31) is normal, and if the equation (31) is not satisfied, the armature current detection unit 32 determines that the equation (31) is abnormal. Here, the determination lower limit value ism_min and the determination upper limit value isum_max are set in advance in consideration of the fluctuation range due to variation factors such as the temperature characteristics of the magnetic sensor and the secular variation.

2. 2. Embodiment 2
The current detection device according to the second embodiment will be described with reference to the drawings. Similar to the first embodiment, the current detection device is incorporated in the AC rotating machine 1 and the control device 10. The description of the same components as those in the first embodiment will be omitted. The basic configuration of the AC rotary machine 1 and the control device 10 according to the present embodiment is the same as that of the first embodiment, but between the first set of armature windings and the second set of armature windings. The phase difference Δθ of the above is different from that of the first embodiment, and accordingly, the setting of the tilt angle θt of each magnetic sensor is different from that of the first embodiment.

In this embodiment, as shown in FIG. 11, the positions of the second set of three-phase armature windings Cu2, Cv2, and Cw2 with respect to the positions of the first set of three-phase armature windings Cu1, Cv1, and Cw1. The phase difference Δθ at the electric angle of is set to Δθ = −π / 3 (−60 degrees).

Therefore, in the present embodiment, a phase difference π / 3 is provided between the coordinate transformation of the first set and the coordinate transformation of the second set in the equations (1) to (4) (the mathematical expression is omitted). ). Further, the current detection values iu1s to iw2s of each phase of each set detected by the magnetic sensor MS of each phase of each set are expressed by the following equations. The phase difference Δθ of the current of the second set of armature windings with respect to the current of the armature windings of the first set is Δθ = −π / 3.

In this case, the detected value of the sum current of the d-axis and the q-axis can be expressed by the equations (33) and (34).

Therefore, by setting each detection error component δ so as to satisfy the equation (35), the detection error component δ of the first set of current and the detection error component δ of the second set of current can be completely canceled out. As shown in the equation (36), the error component of the first order of the electric angle included in the detected value of the sum current of the d-axis and the q-axis can be set to 0.

In order to satisfy the equation (35), for example, the tilt angle θt of each magnetic sensor may be set so as to satisfy the equation (37).

In the equations (35) and (37), the combinations corresponding to the detection error component δ and the inclination angle θt between the sets are set to U2 phase and W1 phase, V2 phase and U1 phase, and W2 phase and V1 phase. As shown in FIG. 11, it is a combination of the first set of phases and the second set of phases having the largest phase difference between the sets.

Therefore, between the armature windings of the first set and the armature windings of the second set, the phase difference of the current (or the phase difference of the position of the armature windings) is the largest with the phase of the first set. In each combination with the second set of phases, the positive and negative signs of the rotor magnetic flux density detection component Bs by the magnetic sensor of the first set of phases and the detection component Bs of the rotor magnetic flux density by the magnetic sensor of the second set of phases. It is preferable that the tilt angle θt of the magnetic sensor of each phase of each set is set so that the positive and negative signs of are the same as each other.

As shown in the equation (9), the detection component Bs of the rotor magnetic flux density is proportional to the detection error component δ of the current due to the magnetic flux of the rotor. Further, if the positive and negative signs of the tilt angle θt of the magnetic sensor are the same, the positive and negative signs of the detection component Bs of the rotor magnetic flux density can be made the same.

According to this configuration, the detection error component δ of the first phase current and the detection error component δ of the second phase current, which have the largest phase difference between the sets in the state of being converted into the d-axis current and the q-axis current. The positive and negative signs are different from each other, and they cancel each other out. Therefore, the detection error of the sum current of the d-axis and the q-axis can be reduced, and the control accuracy of the output torque can be improved.

Further, as in the above-mentioned example, in each of the combinations, the rotor magnetic flux density detection component Bs by the first set of phase magnetic sensors and the rotor magnetic flux density detection component Bs by the second set of phase magnetic sensors are It is preferable that the tilt angle θt of the magnetic sensor of each phase of each set is set so as to be the same as each other.

According to this configuration, the detection error component δ of the first phase current and the detection error component δ of the second phase current, which have the largest phase difference between the sets in the state of being converted into the d-axis current and the q-axis current. It is possible to enhance the effect of canceling each other out.

In the present embodiment, the phase difference Δθ of the current of the second set of armature windings with respect to the current of the armature windings of the first set (the same applies to the phase difference at the electric angle of the winding position) is Δθ = −. It is π / 3. However, if the phase difference Δθ of the current of the second set of armature windings with respect to the current of the armature windings of the first set (the same applies to the phase difference at the electric angle of the winding position) is within the range of the following equation. , The detection error component δ of the first phase current and the detection error component δ of the second phase current, which have the largest phase difference between the sets in the state of being converted into the d-axis current and the q-axis current, cancel each other out. The effect can be obtained.

The phase difference Δθ of the current of the second set of armature windings with respect to the current of the armature winding of the first set (the same applies to the phase difference at the electric angle of the winding position) cancels out within the range of the following equation. The matching effect is enhanced, which is more suitable.

Each magnetic sensor MS was arranged to face the connection line provided in the series circuit of each phase of the switching element on the positive electrode side and the switching element on the negative electrode side in each set of inverters, and each set of inverters was radiated from the rotor. It may be arranged at a place where the radial magnetic fluxes intersect.

Although the present application describes various exemplary embodiments and examples, the various features, embodiments, and functions described in one or more embodiments are applications of a particular embodiment. It is not limited to, but can be applied to embodiments alone or in various combinations. Therefore, innumerable variations not illustrated are envisioned within the scope of the techniques disclosed herein. For example, it is assumed that at least one component is modified, added or omitted, and further, at least one component is extracted and combined with the components of other embodiments.

1 AC rotating machine, 4 field windings, 14 rotors, 18 stators, Bs rotor magnetic flux density detection component, C axis, DS magnetic flux detection direction, MS magnetometer, Por diameter orthogonal plane, R1 1st set ripple component , R2 2nd set ripple component, WR connection line, one side in X1 axial direction, tilt angle in magnetic flux detection direction with respect to θt diameter orthogonal plane, Δθ phase difference

Claims (12)

In an AC rotating machine having a rotor and a stator provided with a first set of n-phase armature windings and a second set of n-phase armature windings (n is an integer of 3 or more), each set of The armature windings of each phase of each set are based on the output signals of the magnetic sensors of each phase of each set arranged opposite to the connection line of each phase of each set that supplies current to the armature windings of each phase. It is a current detector that detects the current flowing through the armature.
The magnetic sensor of each phase of each set is arranged at a position where magnetic fluxes radiated radially from the rotor intersect.
In the first set of n-phase armature windings, the phase of the magnetic flux of the rotor at the electrical angle with respect to the first set of k-phase armature windings is set to θek1, and the first set of k-phase said. When the detection component of the rotor magnetic flux density, which is the component of the magnetic flux density of the rotor detected by the magnetic sensor, is Bsk1, R1 which is the ripple component of the first set is used.

age,
In the second set of n-phase armature windings, the phase of the magnetic flux of the rotor at the electrical angle with respect to the second set of h-phase armature windings is set to θeh2, and the second set of h-phases is described. When the detection component of the rotor magnetic flux density, which is the component of the magnetic flux density of the rotor detected by the magnetic sensor, is Bsh2, the second set of ripple components R2 is used.

When
With respect to a radial orthogonal plane which is a plane orthogonal to the radial direction passing through each of the magnetic sensors so that the positive and negative codes of the first set of ripple components and the positive and negative codes of the second set of ripple components are different from each other. A current detection device in which a tilt angle in the magnetic flux detection direction of the magnetic sensor of each phase of each set is set. The first aspect of claim 1, wherein the tilt angle of the magnetic sensor of each phase of each set is set so that the total value of the ripple component of the first set and the ripple component of the second set becomes zero. Current detector. Δθ, which is the phase difference between the currents of the first set of n-phase armature windings and the currents of the second set of n-phase armature windings, is within the range of −π / 3 <Δθ <π / 3. And
The first set of phases and the second set of phases having the smallest current phase difference between the first set of n-phase armor windings and the second set of n-phase armor windings. In each of the combinations, the positive and negative signs of the detection component of the rotor magnetic flux density by the magnetic sensor of the first set of phases and the positive and negative codes of the detection component of the rotor magnetic flux density by the magnetic sensor of the second set of phases. The current detection device according to claim 1 or 2, wherein the tilt angle of the magnetic sensor of each phase of each set is set so as to be different from each other. In each of the above combinations, the absolute value of the detection component of the rotor magnetic flux density by the magnetic sensor of the first set of phases and the absolute value of the detection component of the rotor magnetic flux density by the magnetic sensor of the second set of phases are determined. The current detection device according to claim 3, wherein the tilt angle of the magnetic sensor of each phase of each set is set so as to be the same as each other. The current detection device according to claim 3 or 4, wherein the Δθ is within the range of −π / 6 ≦ Δθ ≦ π / 6. Δθ, which is the phase difference between the currents of the first set of n-phase armature windings and the currents of the second set of n-phase armature windings, is in the range of -2π / 3 <Δθ <0. ,
The first set of phases and the second set of phases having the largest current phase difference between the first set of n-phase armature windings and the second set of n-phase armature windings. In each of the combinations, the positive and negative signs of the detection component of the rotor magnetic flux density by the magnetic sensor of the first set of phases and the positive and negative codes of the detection component of the rotor magnetic flux density by the magnetic sensor of the second set of phases. The current detection device according to claim 1 or 2, wherein the tilt angle of the magnetic sensor of each phase of each set is set so as to be the same as each other. In each of the above combinations, the detection component of the rotor magnetic flux density by the magnetic sensor of the first set of phases and the detection component of the rotor magnetic flux density by the magnetic sensor of the second set of phases are the same as each other. The current detection device according to claim 6, wherein the tilt angle of the magnetic sensor of each phase of each set is set. The current detection device according to claim 6 or 7, wherein the Δθ is within the range of −π / 2 ≦ Δθ ≦ −π / 6. The current detection device according to any one of claims 1 to 8, wherein the magnetic sensor of each phase of each set is arranged on the same circle centered on the axis. The total value of the sum of the current detection values of the first set of n-phase armature windings and the sum of the current detection values of the second set of n-phase armature windings is set in a preset determination range. The current detection device according to any one of claims 1 to 9, wherein it is determined that an abnormality has occurred when the current exceeds the limit. The current detection device according to any one of claims 1 to 10, wherein the rotor is provided with a field winding. The rotor is a Landel-type rotor in which field windings are wound concentrically around the axis, and one portion in the axial direction of the rotor becomes an N pole or an S pole.
13. The current detector according to any one of the items.

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