JP2000069779A - Matching method for rotating angle sensor of switched reluctance motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a matching method for the rotating angle sensor of a switched reluctance motor, wherein the relative angle between a stator and a rotor can be matched with a detection value on the angle sensor and stable operation can be performed even if the detection accuracy or resolution of the angle sensor is low. SOLUTION: A switched reluctance motor is so formed that the iron core arcuate angle of rotor salient poles is larger than the iron core arcuate angle of its stator, and its actuation is controlled according to the rotating angle sensor. When the switched reluctance motor is started, the phase A and the phase B are simultaneously excited (S21), and operation is waited for a certain time until the vibration of the rotor cases (S22). The angle of the rotor at this time is stored as a reference position in memory (S23), and excitation of the phase A and that of the phase B are simultaneously stopped (S24).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an angle sensor matching method for matching a relative angle between a stator and a rotor in a switched reluctance motor with a value detected by an angle sensor.

[0002]

2. Description of the Related Art A switch reluctance motor detects a rotation angle (position) of a rotor with respect to a stator, selects an optimum excitation phase at each rotation angle, and switches energization. For detecting the rotation angle, a potentiometer as an absolute type angle sensor, a rotary encoder or a resolver as an incremental type angle sensor, or the like is used. In the former absolute type, since the rotation angle is added to the angle of the angle sensor and detected, if the rotation angle of the rotor and the detection value of the angle sensor are previously mechanically matched, the detection value of the angle sensor The rotation angle of the rotor is uniquely determined. On the other hand, the latter incremental type relatively detects the rotation angle from the time when the angle sensor is activated, so that the rotation angle of the rotor and the detection value of the angle sensor need not be matched by any means at the time of activation. Not be. Even in the case of the former absolute type, if there is a large variation in the mounting angle during mass production or a large variation in the detected value, it is better to make the alignment at the time of startup.

Conventionally, as an initial driving method for matching the rotation angle of the rotor at the time of starting and the detection value of the angle sensor, for example, a reluctance motor described in Japanese Patent Application Laid-Open No. Hei 5-316777 is used. How to start ". In this conventional example, one phase is excited for a certain period of time at the time of startup, and any salient pole of the rotor is opposed to the excited salient pole of the stator. Since this state is in principle a position where the salient poles of the stator and the rotor completely face each other, if, for example, an incremental type angle sensor is used, the rotation angle of the rotor will be relative to this position based on this position. What is necessary is just to recognize by a corner.

This will be described in detail with reference to the drawings. First, FIG. 9, FIG.
0 shows the structure of a conventional switched reluctance motor. The switch reluctance motor of FIGS. 9 and 10 has windings 010 to 01 on salient poles 04 to 09 of the stator 01.
5 are wound in a concentrated winding, and the opposite salient poles 0
4 and 07, 05 and 08, and 06 and 09, the windings 010 and 013, 011 and 014, and 012 and 015
Are connected in series. The angle sensor 016 is mounted on the axis of the rotating shaft 03 so as not to rotate with respect to the stator 01. Here, if the A phase is the windings 010 and 013, the B phase is the windings 01 and 014, and the C phase is the windings 012 and 015, the energization is switched in the order of A phase → B phase → C phase → A phase. The salient poles of the rotor 02 are attracted to the energized salient poles and rotate clockwise.

Next, a conventional alignment method of an angle sensor will be described. FIG. 11 shows that the width of the salient poles of the stator and the rotor is both 30.
Degree of switch reluctance motor. When only the A-phase 020 is excited by the conventional initial drive method, a magnetic flux 023 indicated by a thick line in the drawing is generated. In the magnetic path of the magnetic flux 023, the rotor rotates to a position where the magnetic resistance becomes minimum and stably stops. Since it is the position where the facing area between the salient poles of the stator and the salient poles of the rotor is maximized, A
This is a position where the salient poles 021 of the phase 020 and the salient poles 022 of the rotor completely oppose each other (positions at which the center lines of the salient poles 21 and 022 coincide with each other). This will be described with reference to a static torque characteristic (hereinafter, referred to as θ-T characteristic) represented by the rotor angle θ and the torque T. FIG. 12 is a θ-T characteristic diagram when only the phase A is excited with a constant current. The position where the salient pole of the rotor completely opposes the salient pole of the A phase, that is, the position in FIG. 11 is set to 0, and the rotor angle θ is set clockwise. When θ is near 0, if it is located in the negative direction, torque in the positive direction is applied, and if it is located in the positive direction, torque in the negative direction is applied. Therefore, the rotor angle θ = 0 is a stable point. Thus, A
Since the stable point when the phase is excited is known in advance,
The angle sensor can be matched by setting that position as a reference position a certain time after the excitation of the phase and the vibration of the rotor has subsided. FIG. 13 shows the θ-T characteristics of the A-phase and the B-phase at this time. By switching the excitation from the A-phase to the B-phase at the angle of E, a substantially constant torque is continuously generated, and the torque is stabilized. Can be rotated.

However, such a switch reluctance motor in which the salient poles of the stator and the rotor both have a width of 30 degrees has a problem in that the detection accuracy of the angle sensor is poor or the resolution is coarse, or the angle sensor is mounted at a gear down position. If the detected value deviates from the original angle due to the backlash of the gears on the rotating shaft, the excitation switching angle may become F, for example, and the reverse torque of the A phase occurs. Rotation may not be stable. This is because the A-phase originally generates a positive torque from −45 degrees to 0 degrees, but the excitation switching angle is near its limit of 0 degrees. Therefore, the B phase generates a positive torque from -15 to 30 degrees, so if the excitation switching angle can be -7.5 degrees, which is the center angle of -15 to 0 degrees where the torques overlap, an angle sensor Even if the detection error is ± 7.5 degrees, no reverse torque is generated. As a simple method of realizing this, there is a method in which a constant torque region in one phase is expanded to increase the overlap of torque between phases. FIG. 14 shows this, in which the constant torque overlaps the entire range from -15 degrees to 0 degrees, so that the excitation switching angle can be determined to -7.5 degrees. However, providing this torque characteristic corresponds to increasing the salient pole width of both the stator and the rotor. Specifically, in order to create a constant torque region of 45 degrees, the salient pole widths are both set to 45 degrees. There is a need to. Therefore, although this method can be operated stably, another problem that the winding insertion space between the salient stator poles is narrowed, and as a result, the number of windings is reduced and the torque is reduced is caused. .

Therefore, as the next method, there is a method of shifting only the phase in a constant torque region in the torque waveform of FIG. That is, if the constant torque is generated in the region as shown in FIG. 15, the overlap of the constant torques of the A phase and the B phase is near the center between -15 degrees and 0 degrees. The excitation switching angle is determined. The salient pole shape that realizes this torque characteristic has a salient pole of the stator of 30 degrees and a salient pole width of the rotor of 45 degrees. According to this method, even if the detection error of the angle sensor is ± 7.5 degrees, no reverse torque is generated and the motor can be rotated stably, and as shown in FIG. Absent.

[0008]

However, in such a switched reluctance motor in which the salient poles of the stator and the rotor have different widths, as shown in FIG. 15, the torque near the stable point (zero cross) drops. In the conventional method of exciting only one phase in the initial drive for matching the rotation angle of the rotor with the detection value of the sensor, the rotor cannot be accurately stopped at a stable point, Is shifted. The present invention has been made in view of the above-mentioned conventional problems,
The angle of the switch reluctance motor enables stable operation even when the relative angle between the stator and the rotor and the detection value of the angle sensor can be reliably performed and the detection accuracy of the angle sensor is poor or the resolution is coarse. It is intended to provide a sensor matching method.

[0009]

Therefore, even in a switched reluctance motor in which the salient poles of the stator and the rotor have different widths, the initial position of the rotor is accurately settled at a stable point and a reference position is obtained. In driving, a plurality of phases are excited simultaneously.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) Embodiment 1 will be described with reference to FIGS. The initial drive according to the present embodiment will be described with reference to the flowchart of FIG. First, only the A-phase 2 is excited in S11. At this time, the magnetic flux 3 generated as shown in FIG. 2 causes the salient pole of the rotor 1 to be drawn to a position substantially opposed to the salient pole of the A-phase 2. The substantially opposing position is within a range of ± {(rotor salient pole width) − (stator salient pole width)} / 2 from a position where the center lines of the salient poles coincide with each other.

Next, a wait is performed for a predetermined time in S12, and S1
Proceed to 3. This fixed time is determined in advance as a time until the vibration of the rotor 1 stops. In S13, B
Excite phase 4 further. At this time, as shown in FIG.
The generated magnetic flux 5 generates a clockwise torque at the other salient poles 6 and 7 of the rotor 1. When rotated clockwise with this torque, the magnetic flux 3 of the A phase 2 becomes the magnetic flux 5 of the B phase 4.
Finally, a magnetic flux 9 shown in FIG. 4 is generated.

Next, a wait is performed for a predetermined time in S14, and S1 is performed.
Go to 5. This fixed time is also determined in advance as a time until the vibration of the rotor 1 stops. As a result, FIG.
As shown in (1), the rotor 1 stops at a position where the center line of the salient pole is rotated by 15 degrees from the center line of the salient pole of the stator 8.
This position is a stable point when the A-phase 2 and the B-phase 4 are simultaneously excited. In S15, the value of the angle sensor at this time is stored in the memory as equivalent to 15 degrees, and in S16, the value of A
Excitation is stopped in both phase 2 and phase B 4. This is the end of the initial drive according to the present embodiment.

In this embodiment, as described above, only one phase is first excited before simultaneously exciting two phases. The reason will be described with reference to FIG. The figure is a θ-T characteristic diagram when two phases are excited simultaneously. The torque is 0 within the range of ± [45 − {(salient pole width of rotor) − (salient pole width of stator)} / 2] degrees to ± 45 degrees.
The unstable equilibrium point of If the rotor 1 is located in this range at the time of starting, even if two phases are excited at the same time, the rotor 1 does not move at all from that position. Therefore, in the present embodiment, first, one phase is excited to be fixed at a position of −15 degrees, and thereafter, two phases are excited.

Therefore, according to the present embodiment, no matter what angle the rotor 1 is positioned at the time of startup, the alignment can be reliably achieved. In the present embodiment, phase A and phase B
Although the phases were excited, it is sufficient if the phases are electrically adjacent to each other.
The same effect can be obtained for the phases C and C, and the phases C and A, and the interpretation of the initial values stored in the memory may be matched. Further, when the angle sensor is configured by an incremental encoder and a counter, S15 in FIG.
In this case, the counter may be preset to 15 degrees.

(Embodiment 2) Next, Embodiment 2 will be described with reference to FIGS. 6 and 7 show a throttle chamber of an automobile engine operated by a switch reluctance motor. The rotation of the switch reluctance motor 10 is reduced by the reduction gears 11, 12, and 13 and transmitted to the rotation shaft 14 of the throttle valve 15 to drive the throttle valve 15 to open and close. The rotary shaft 14 of the throttle valve 15 is provided with a potentiometer 16 for measuring the opening of the throttle valve 15, and the spring 17 pushes the throttle valve 15 in the closing direction. The switch reluctance motor 10 is not provided with an angle sensor coaxially, and obtains the rotation angle by multiplying the signal of the potentiometer 16 by the gear ratio.

In such a manufacturing method of the throttle chamber, when the throttle valve 15 is closed by being pressed by the spring 17, the center line of the salient pole of the rotor 20 of the switch reluctance motor 10 is set to the A phase 2
The rotor 20 is mounted so as to have an angle of (15 degrees ± tolerance) with respect to the center line of one salient pole. Then, in the initial drive of the switch reluctance motor 10, as shown in the flowchart of FIG. 8, two phases (A phase 20, B phase 22) are simultaneously excited from the beginning (S2).
1). This means that the position of the rotor 20 at the time of startup is ± [45 − {(salient pole width of the rotor) − (salient pole width of the stator)} / 2} degrees with respect to the stable point when the two phases are simultaneously excited. This is because it is possible to assemble so as to be positioned within the range of the above, and the time required for the initial drive can be shorter than in the first embodiment. Note that S22 to S24
The processing up to is the same as the processing from S14 to S16 in FIG. 1, and the description thereof is omitted.

[0017]

As described above, according to the method for aligning the angle sensor of the switched reluctance motor of the present invention,
Even in the initial drive of a switched reluctance motor where the width of the salient poles of the stator and rotor is different, the rotor is accurately stopped at a stable point so that the reference position can be obtained.
The alignment of the angle sensor can be reliably performed, and stable operation can be performed even when the detection accuracy of the angle sensor is low or the resolution is coarse.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating initial drive of a switched reluctance motor according to Embodiment 1 of the present invention.

FIG. 2 is a diagram illustrating initial drive of a switched reluctance motor according to the first embodiment.

FIG. 3 is a diagram illustrating initial drive of a switched reluctance motor according to the first embodiment.

FIG. 4 is a diagram illustrating an initial drive of the switched reluctance motor according to the first embodiment.

FIG. 5 is a θ-T characteristic diagram when two phases of the switched reluctance motor of the first embodiment are simultaneously excited.

FIG. 6 is a front view showing a throttle chamber of an automobile engine operated by the switched reluctance motor according to the second embodiment.

FIG. 7 is a side view showing a throttle chamber of an automobile engine operated by the switched reluctance motor according to the second embodiment.

FIG. 8 is a flowchart illustrating an initial drive of a switched reluctance motor according to a second embodiment.

FIG. 9 is a perspective view showing a structure of a conventional switched reluctance motor.

FIG. 10 is an explanatory view showing the structure of a conventional switched reluctance motor.

FIG. 11 is a diagram illustrating a conventional alignment method of an angle sensor.

FIG. 12 shows θ- of a conventional switched reluctance motor.
It is a T characteristic diagram.

FIG. 13 shows θ- of a conventional switched reluctance motor.
It is a T characteristic diagram.

FIG. 14 shows θ- of a conventional switched reluctance motor.
It is a T characteristic diagram.

FIG. 15 shows θ- of a conventional switched reluctance motor.
It is a T characteristic diagram.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotor 2 A phase 3 Magnetic flux 4 B phase 5 Magnetic flux 6 Salient pole 7 Salient pole 8 Stator 9 Magnetic flux 10 Switch reluctance motor 11 Reduction gear 12 Reduction gear 13 Reduction gear 14 Rotary shaft 15 Throttle valve 16 Potentiometer 17 Spring 20 Rotor 21 A Phase 22 Phase B

Claims (4)

[Claims] 1. A switch reluctance motor in which a salient pole of a rotor has a larger arc angle than a core of a salient pole of a stator, an angle sensor for detecting an angle of the rotor, and the angle sensor. A control circuit for controlling the operation of the switch reluctance motor based on the angle signal of the switch reluctance motor system, wherein the relative angle between the stator and the rotor and the angle signal of the angle sensor are matched. A method for aligning an angle sensor of a switched reluctance motor, comprising: exciting a plurality of phases together at the start of startup of the switched reluctance motor; and, after a predetermined time, setting a rotor angle at that time as a reference position. . 2. One phase is first excited, and after a certain time,
2. The method according to claim 1, further comprising: exciting another phase, and after a predetermined time, the angle of the rotor at that time is used as a reference position.
A method for aligning an angle sensor of a switch reluctance motor according to the above description. 3. The angle sensor matching method for a switched reluctance motor according to claim 1, wherein the excitation of the two phases is started at the same timing, and after a predetermined time, the rotor angle at that time is used as a reference position. . 4. An angle sensor for a switch reluctance motor according to claim 1, wherein the mounting position of the angle sensor is on a rotation axis of a gear for increasing or decreasing the rotation of the rotor. Alignment method.