JP2001128490A - Switched reluctance motor and rotation-control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-scale rotation-control device that can accurately detect the rotation position of the rotor of a switched reluctance motor, even if a power voltage is reduced. SOLUTION: In the rotation-control device, when an excitation current is energized to a U phase, the winding inductance of V and W-phases is detected (S52), is compared (S54), and is energized from the U-phase to the W-phase when the W-phase becomes larger than the V phase (S56). Then, the winding inductance of the U and V phases is compared, furthermore, that of the U and W phases is compared, and the switching destination of the excitation current is successively changed in the order of W, V, and U phases (S58 to S68). In this manner, by comparing the value of the winding inductance of the winding of two phase where the excitation current is not energized, accurate switching timing is detected, thus smoothly changing the conduction destination of the excitation current.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation control device for controlling the rotation of a switched reluctance motor without using a resolver, and a switched reluctance motor provided with the rotation control device.

[0002]

2. Description of the Related Art Heretofore, there has been known a rotation control device which detects a rotational position of a rotor provided in a switched reluctance motor without using a resolver, and performs control of switching an energizing current supply destination based on the detected result. Have been.

[0003] As such a rotation control device, for example, the paper of the Institute of Electrical Engineers of Japan, RM-98-154 (P43-P48), “SR
Examination of Sensorless Operation of Motor "(hereinafter referred to as" Example 1 "). In Example 1, the winding impedance of the winding wound on the rotor changes in accordance with the distance between the salient pole of the stator on which the winding is wound and the salient pole of the rotor (both salient poles are opposed to each other). The coil impedance becomes the maximum when it comes to the position where it does). Specifically, first, to detect the winding impedance,
A step function voltage is applied to a series circuit of a resistor and a winding for voltage division, and a voltage between windings (hereinafter, referred to as “detection voltage”) generated in the winding after a predetermined time according to the magnitude of the winding impedance. Detected. Then, a reference voltage, which is a detection voltage of the rotation position at which the excitation current starts to be supplied, is obtained in advance, and the detected voltage is compared with the reference voltage so that the rotor reaches the rotation position at which the excitation current starts to be supplied. Is detected. Then, when it is detected that the rotor has reached the predetermined rotational position, the destination of the excitation current is switched.

In the rotation control device disclosed in Japanese Patent Application Laid-Open No. Hei 9-15863 (hereinafter referred to as "Example 2"), a high-frequency pulse is applied to a certain winding, and when a current flowing through the winding reaches a certain reference value. In addition, control is performed to switch the destination of the excitation current. Further, in the rotation control device disclosed in Japanese Patent Application Laid-Open No. 1-164288 (hereinafter referred to as "Example 3"), a low-level pulse is applied to the windings to which no exciting current is applied, and the estimated inductance value of each winding is calculated. The position of the rotor is determined using mapping data representing the relationship between the estimated inductance value and the rotational position of the rotor.

[0005]

When this switched reluctance motor is used in a vehicle or the like, a battery provided in the vehicle is used as a power source for the detected voltage. The battery is provided in the vehicle. When a device that consumes a large amount of power, such as a cooler, operates, the voltage value may decrease temporarily. When a battery is used for a long period of time, the battery may be exhausted and may not be charged at a required voltage value.

Therefore, as in the first embodiment, when the detected voltage is compared with the reference voltage to detect the rotational position of the rotor, if the voltage of the battery changes, the voltage value of the detected voltage does not change. Therefore, the comparison result becomes inaccurate even when compared with the reference voltage, and as a result, there has been a problem that the rotational position of the rotor cannot be accurately detected.

This problem is the same in Example 2. on the other hand,
In Example 3, since the mapping data is used, a storage circuit for storing the mapping data is required, and there is a problem that the rotation control device becomes large in scale.

Accordingly, an object of the present invention is to provide a small-scale rotation control device that can accurately detect the rotational position of the rotor of a switched reluctance motor even when the power supply voltage decreases.

[0009]

According to a first aspect of the present invention, there is provided a rotation control device which, when a switched reluctance motor is started, converts each of the oscillation frequencies detected by frequency detection means into a winding. A comparison is made between the oscillation circuits as elements, and the winding to which the excitation current is to be applied first is determined according to the rotational position of the rotor determined from the magnitude relationship of the oscillation frequencies between the oscillation circuits.

Further, in the switched reluctance motor according to the fourth aspect, the winding to which the exciting current is first supplied is determined in the same manner as in the rotation control device according to the first aspect. The rotation control device according to claim 1 or claim 4.
If the rotational position of the rotor is detected by using the result of comparing the oscillation frequencies of the windings as elements as in the rotation control device of the switched reluctance motor described above, the oscillation frequency can be changed even if the power supply voltage fluctuates. Since the magnitude relationship is not affected by the fluctuation, the magnitude relationship can be accurately compared. As a result, the rotational position of the rotor (more specifically, the winding to which the exciting current is first applied) can always be accurately detected.

Therefore, when the rotation control device according to the first aspect or the switched reluctance motor according to the fourth aspect is used, the rotor can always be started smoothly. Further, since the rotation control device according to the first aspect or the switched reluctance motor according to the fourth aspect detects the rotational position of the rotor without using the mapping data, it is necessary to provide a storage circuit for storing the mapping data. There is no. Therefore, when the rotation control device according to the first aspect or the switched reluctance motor according to the fourth aspect is used, the size of the rotation control device can be reduced.

As described above, if the oscillation frequency of the oscillation circuit having each winding as an element is detected during stoppage, the rotational position of the rotor can be accurately detected from the magnitude relationship. Since it is not possible to oscillate the winding through which the current flows, the oscillation frequency cannot be detected.

Therefore, in the rotation control device according to the present invention, an oscillation circuit having windings as elements is provided for each winding, and during the rotation of the switched reluctance motor, the windings to which no exciting current is applied are first turned on. The oscillation frequency of the non-energizing oscillation circuit is detected so that the non-energizing oscillation circuit oscillates, and the oscillation frequency of the non-energizing oscillation circuit having the designated winding determined by the winding in which the exciting current is energized is detected. The switching timing at which the magnitude relationship is inverted is detected, and the destination of the excitation current is switched at the switching timing.

In the switched reluctance motor according to the fifth aspect, the switching timing is detected in the same manner as in the rotation control device according to the second aspect, and the destination of the excitation current is switched at the switching timing. In the rotation control device according to the second aspect or the switching motor according to the fifth aspect,
Since the oscillation frequency of the non-conducting oscillation circuit having the non-conducting winding as an element is detected and the switching timing of the exciting current is detected from the magnitude relationship, even if the voltage value of the power supply voltage changes,
By detecting an accurate switching timing, it is possible to smoothly change the destination of the excitation current.

When the switch reluctance motor is a three-phase motor, such as the rotation control device according to the third aspect or the switch reluctance motor according to the sixth aspect, an exciting current is applied to the designated winding. The other two phase windings except for the phase winding.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment to which the above-described invention is applied will be described below. Here, FIG. 1 shows a switched reluctance motor (hereinafter referred to as “SR motor”).
3 is an axial sectional view of FIG.

As shown in FIG. 1, the SR motor 1 of this embodiment has six teeth 2a (hereinafter referred to as "salient poles 2a") protruding in the radial direction on the inner wall surface of a cylindrical body 2b. ), And a rotor 3 provided inside the stator 2 and having four salient poles 3a protruding in the radial direction on the outer periphery of a cylindrical main body 3b.
In this SR motor, the salient poles 2a of the stator 2 are arranged at regular intervals every 60 degrees, and the salient poles 3a of the rotor 3 are arranged at regular intervals every 90 degrees.
When the rotor 3 is rotated, the salient pole 3a of the rotor 3 passes through a position facing the salient pole 2a of the stator 2.

In the SR motor 1 of this embodiment, the windings 4, 5, and 6 are wound so that the salient poles 2a of the stator 2 facing each other have the same phase. The pole 2a is U-phase, the salient pole 2a of the winding 5 is V-phase, and the salient pole 2a of the winding 6 is W
The motor is configured as a three-phase motor having three phases.

In the SR motor 1 configured as described above, when an exciting current is applied to the windings 4, 5, and 6, an attractive force due to magnetic saliency acts between the salient poles 2a and 3a. It rotates using the suction force. Specifically, an example in which the rotor 3 is rotated in the direction of U phase → V phase → W phase in FIG. 1 will be described.
Phase and the position facing the salient pole 2a of the U phase, the salient pole 3a located between the W phase and the V phase (hereinafter referred to as "salient pole 3a-1") is the W phase. To excite the winding 6 to the salient pole 2a around which the winding 6 is wound, and rotate the rotor 3 in the direction from the V phase to the W phase. Then, at this time, the salient pole 3a facing the U-phase at the time of starting (hereinafter referred to as “salient pole 3a-2”) comes to a position between the U-phase and the V-phase. Is switched from the W-phase winding 5 to the V-phase winding 5, the salient pole 3a-2 is drawn to the V-phase salient pole 2a, and the rotor 3 is further rotated. And salient pole 3
When a-2 comes to a position facing the V-phase salient pole 2a, the salient pole 3a-1 comes to a position between the U-phase and the W-phase. By pulling the pole 3a-1 toward the U-phase salient pole 2a, the rotor 3 is further continuously rotated.

Next, a drive circuit for rotating the SR motor 1 will be briefly described. Here, FIG.
FIG. 3 is a circuit diagram of a drive circuit of the R motor 1. This drive circuit 8
As shown in FIG. 2, a battery BT that supplies an exciting current to each of the windings 4, 5, and 6 and a supply circuit that is wired to supply the exciting current from the battery BT to each of the windings 4, 5, and 6 The switches 9 (9a, 9b, 9
c) and the switch 10 (10a, 10b, 10c);
A diode 11 (11) provided on a regenerative electric circuit for regenerating a regenerative current from each of the windings 4, 5, 6 to the battery BT.
a, 11b, 11c) and the diode 12 (12a, 1
2b, 12c) and a rotation control circuit 20 for controlling the rotation of the rotor 3 by turning on and off the switches 9, 10.

The drive circuit 8 uses a rotation control circuit 20 to turn on and off the switches 9 and 10 sequentially, and connects the windings 4, 5, and 6 to the battery BT in accordance with the turning on and off of the switches 9 and 10.
Are sequentially connected to sequentially switch the energization destination of the excitation current. The drive circuit 8 has a connection point α (α1 to α) between the switch 9 and the windings 4, 5, and 6.
3) From the connection point β (β1 to β3) between the switch 10 and the windings 4, 5, 6 to the rotation control circuit 20, the winding 4 is connected to an oscillation circuit (described later) provided in the rotation control circuit 20. ,
Connection lines for connecting 5, 6 are provided.

Next, in the SR motor 1 of the present embodiment, it is necessary to detect the rotational position of the rotor 3. Hereinafter, a method of determining the rotation position of the rotor 3 and determining the windings 4, 5, and 6 through which the exciting current is applied to rotate the rotor 3 will be described, and then the method for rotating the rotor 3 according to this method will be described. The rotation control circuit 20 will be described, and various processes for controlling the rotation of the rotor 3 using the rotation control circuit 20 will be described.

First, a method for grasping the rotational position of the rotor 3 will be described. Here, FIGS. 3A and 3B show the SR
FIG. 3 is an axial sectional view of the motor 1. FIG. 3C is a θ-L graph showing a change in the winding inductance L of each of the windings 4, 5, and 6 with respect to the rotational position θ of the rotor 3. FIG. 4 is a θ-L graph for explaining changes in all three phases of the U, V, and W phases of the winding inductance L with respect to the rotational position θ of the rotor 3. In FIG. 4, the rotation position at the point where the salient pole 2a around which the U-phase winding is wound and the salient pole 3a of the rotor 3 face each other is represented by a rotation angle of 0 degree.

Table 1 is a correspondence table between the change pattern of the winding inductance L of the windings 4, 5, and 6 and the switching pattern of the excitation current supply destination during the rotation of the SR motor 1. Table 2 shows that when the SR motor 1 is started,
The magnitude relationship between the winding inductances L of the windings 4, 5, and 6,
4 is a correspondence table with phases to which an excitation current is to be applied first. still,
Hereinafter, simply U, V, and W indicate the magnitude of the winding inductance L of each phase.

First, the winding inductance L of the windings 4, 5, and 6 constituting the SR motor 1 of the present embodiment is, as shown in FIG. When the salient poles 2a and the salient poles 3a of the rotor 3 face each other and are completely aligned, the maximum is obtained (hereinafter, the rotational position of the rotor 3 at which the winding inductance L takes the maximum value is hereinafter referred to as a peak rotational position). As shown in FIG. 3 (b), both salient poles 2
It is known that the minimum is obtained when a and 3a do not face each other and are not aligned at all.

The winding inductance L depends on the rotor 3
Is rotated to bring both salient poles 2a and 3a closer to each other.
As shown in FIG. 7, the ascending pole rises almost directly in proportion to the rotational position θ of the rotor 3, while falling as the both salient poles 2 a and 3 a move away. When the rotor 3 continues to rotate, the winding inductance L takes a minimum value for a while without the two salient poles 2a, 3a being completely aligned, and then the salient pole 3a of the rotor 3 approaches the salient pole 2a again. Is known to rise in direct proportion.

Looking at all the winding inductances L of the respective phases which change in this way, as shown in FIG. 4, when the winding inductance L of a certain phase (for example, U phase) takes the maximum value ( Point a), that is, when the rotor 3 comes to one of the peak rotation positions (the peak rotation position is the rotation position indicated by the arrow in FIG. 4), the other two phases (for example, the V phase and the W phase). It was experimentally found that the magnitude relation of the winding inductance L was reversed (point b). That is, when the winding inductance L of a certain winding (for example, the winding 4) takes the maximum value, the winding inductance L cannot be measured because an exciting current is usually applied to the winding 4. When the winding inductance L of the windings of the other phases (in this case, the windings 5 and 6) is measured, the timing at which the winding inductance L of the winding to which the exciting current is applied takes a maximum value, that is, the exciting current Can be detected.

[0028]

[Table 1]

Therefore, during the rotation of the SR motor 1, as shown in Table 1, the rotation direction of the rotor 3 is changed from U-phase to V-phase to W-phase.
Assuming that the phase is the phase, the U-phase winding inductance L becomes maximum at the rotation position where the magnitude of the V-phase and W-phase winding inductance L becomes from V> W to V ≦ W (peak rotation position at point a). Therefore, at this time, if the energization destination of the exciting current is changed from the U phase to the W phase, the rotor 3 rotates in the above-described rotation direction.
Further, when the magnitude of the winding inductance L is from U> V to U ≦ V
At the rotational position where V is reached, the W-phase winding inductance L is maximized (the peak rotational position at point e). At this time, the excitation current may be changed from the W phase to the V phase. Further, the magnitude of the winding inductance L is from W> U to W ≦ U
At the rotation position, the winding inductance L of the V phase becomes maximum (the peak rotation position at the point f). At this time, the excitation current may be changed from the V phase to the U phase.

On the other hand, when the protrusion 3a is not completely opposed to any of the protrusions 2a and is located at a position between any of the protrusions 2a, the winding inductance L becomes, as shown in FIG. For example, the winding inductance L of the W phase) has the lowest value, and the winding inductance L of the phase having the lowest value.
However, it has been experimentally found that the winding inductance L is not larger than the winding inductance L of the other two phases (in this case, the U phase and the V phase). That is, usually, when the SR motor 1 is started, each of the windings 4,
Although the position of the rotor 3 cannot be grasped only by measuring the winding inductances L of the windings 5 and 6,
By comparing the magnitude relationship between the winding inductances L of the windings 5 and 6, it is possible to accurately grasp which of the windings 4, 5 and 6 is at the position where the exciting current should be applied first.

[0031]

[Table 2]

Therefore, when the SR motor 1 starts, the rotor 3
Is rotated in the rotation direction described above, as shown in Table 2, when the protrusion 3a is between the W phase and the U phase and between the W phase and the V phase, the magnitude of the winding inductance L is Since U ≧ W and V> W (section of FIG. 4), in such a case, the excitation current may be applied to the U-phase winding 4 first.
When the salient pole 3a is between the V phase and the W phase and between the V phase and the U phase, the magnitude of the winding inductance L is W ≧ V
In addition, since U> V (section in FIG. 4), the excitation current may be applied to the W-phase winding 4 first. Furthermore, salient pole 3
When a is between the U and V phases and between the U and W phases, the magnitude of the winding inductance L is V ≧ U and W> U
(Section in FIG. 4), the excitation current may be applied to the V-phase winding 4 first.

Next, by comparing the winding inductances L of the respective phases, the rotational position of the rotor 3 is detected, and the rotor 3 is rotated in accordance with the method of determining the windings 4, 5, and 6 for supplying the exciting current. Of the rotation control circuit 20 will be described.
First, a method for grasping the rotational position of the rotor 3 will be described.

FIG. 5 is a schematic diagram of the rotation control circuit 20. As shown in FIG. 5, the rotation control circuit 20 includes a frequency detection circuit 30 having windings 4, 5, and 6 as elements.
(30U, 30V, 30W), this frequency detection circuit 30 (30U, 30V,
30W) oscillation frequency is detected and the magnitude relation is determined.
Based on this determination, the determination switching unit 40 that switches the destination of the excitation current and the windings 4, 5, and 6 are connected to the frequency detection circuit 30.
(30U, 30V, 30W) or the battery BT.

First, the frequency detection circuit 30 (corresponding to the oscillation circuit of the present invention) includes the windings 4 and 4 as shown in FIG.
5, 6 and two capacitors 32 (32U, 32V, 32W) connected in series for each of the windings 4, 5, 6; and a positive feedback for positively feedbacking the oscillation in the reactance circuit. It comprises a well-known Colpitts oscillation circuit composed of elements (34U, 34V, 34W). The frequency detection circuit 30 oscillates when the switch 50 is operated to connect the windings 4, 5, 6 of a predetermined phase to capacitors (32U, 32V, 32W).

The oscillation frequency f of the frequency detection circuit 30
Is represented by f = 1 / {2π (L * (C1 * C2 / (C1 + C2))) − ^1/2 } − (1). Of these (1), capacitors C1 and C2
Is constant. Therefore, the oscillation frequency f of the frequency detection circuit is uniquely determined by the winding inductance L of the windings 4, 5, and 6, and the change in the winding inductance L is detected by detecting the oscillation frequency f. It can be easily obtained from equation (1).

In the frequency detecting circuit 30 of this embodiment,
A Colpitts oscillation circuit is formed by connecting a capacitor 32 (32U, 32V, 32W) to the windings 4, 5, and 6, but a Hartley oscillation circuit in which one of the capacitors 32 is replaced with a coil may be used. Any oscillation circuit having the windings 4, 5, and 6 as elements may be configured.

Next, the determination switching section 40 detects and compares the oscillation frequency from each of the frequency detection circuits 30 (30U, 30V, 30W), operates the switch 50 based on the comparison result, and operates the switch 50 at the time of starting which will be described later. Processing or rotation processing is performed. Next, the switch 50 is connected to a capacitor 32 (32U, 32V, 32W) and an electric circuit connecting the windings 4, 5, and 6 (an electric circuit from the connection point α or β in FIG. 2 to the capacitor 32 of the rotation control circuit 20). ) And switches 9, 10 for connecting the windings 4, 5, 6 to the battery BT (see FIG. 2). The switch 50 uses the switches 9 and 10 according to the instruction from the determination switching unit 40 to
And the windings 4, 5, and 6 of each phase are freely connected and disconnected.
Using a switch (not shown), the windings 4, 5, and 6 and the capacitor 32 (32U, 32V, 32W) can be freely switched on and off.

Next, various processes for controlling the rotation of the rotor 3 using the rotation control circuit 20 configured as described above will be described. Here, FIG. 6 is a flowchart of a start-time process when the SR motor 1 is started. FIG.
5 is a flowchart of a process at the time of rotation when the SR motor 1 is rotating.

First, at the time of starting the SR motor 1, as shown in FIG.
That is, the U-phase winding and the capacitor 32U are connected (S1
0), the oscillation frequency of the frequency detection circuit 30U is detected.
Thereafter, the oscillation frequency is detected for the V phase and the W phase in the same manner as in S10 (S12, S14). The reason why the oscillation frequency is detected one phase at a time is that the frequency detection circuit detects the oscillation frequency by the oscillation of another frequency detection circuit 30 in order to accurately detect the position of the rotor 3. This is to prevent the oscillation of 30 from affecting the detection of the oscillation frequency.

Next, based on the oscillation frequencies detected in S10 to S14, the winding inductance of the windings 4, 5, and 6 becomes U
It is determined whether or not ≧ W and V> W (S16). If the determination is affirmative, the switch 50 is operated to operate the winding 4 and the capacitor 32.
U (S18), and the battery B is connected to the U-phase winding 4.
T is connected (S20) to supply an exciting current to the winding 4, and the process (S1) ends.

Next, if a negative determination is made in S16, it is determined whether W ≧ V and U> V (S22), and if a positive determination is made, the W-phase winding 6 and the capacitor 32W are disconnected (S2).
4) Connect the W-phase winding 6 to the battery BT (S26)
Then, an exciting current is supplied to the winding 6, and the process (S1) is completed.

Next, if a negative determination is made in S22, it is determined whether V ≧ U and W> U (S28), and if a positive determination is made, the V-phase winding 5 and the capacitor 32V are disconnected (S3).
0), the V-phase winding 5 is connected to the battery BT (S3
2) Then, an exciting current is supplied to the winding 5 to end the processing (S1). If all of the determinations in S16, S22, and S28 are negative, it is determined that the startup process S1 did not operate normally, and the process (S1) is performed again.

In this process, the oscillation frequency is detected only once, but the processes of S16, S22, and S28 may be repeated to detect the rotational position of the rotor 3 more accurately. In this case, S16, S22, S2
After performing the process of repeatedly detecting step 8 in a predetermined number of times, it is only necessary to determine from which phase excitation has been started, and to connect the switch 50 of any phase to the battery BT. .

Next, the rotation process when the SR motor 1 is rotating will be described. This rotation process (S5)
Is performed subsequent to the above-described startup process (S1). When the rotation process (S5) is started, first, FIG.
As shown in the flowchart, it is determined whether or not it is immediately after the start (S50). A negative determination is made in this determination (S50:
NO), first, since the exciting current is applied to the U-phase winding 4, the detection of the oscillation frequency of the frequency detection circuit 30 using the V-phase and W-phase windings 5 and 6 as elements starts. Is performed (S52). The detection of the oscillation frequency is performed until the switching timing at which it is determined that the W-phase winding inductance L is larger than the V-phase winding inductance L (V> W → V ≦ W) (S54). If an affirmative determination is made in S54, the switch 50 is switched, and the exciting current is supplied to the W-phase winding 6 (S56).

When the exciting current is supplied to the W-phase winding 6 in S56, the oscillation frequency of the frequency detection circuit 30 using the U-phase and V-phase windings 4 and 5 as elements is detected. It is started (S58). The detection of the oscillation frequency is performed until the switching timing at which it is determined that the V-phase winding inductance L is larger than the U-phase winding inductance L (U> V → U ≦ V) (S60). If the determination in S60 is affirmative, the switch 50 is switched, and the exciting current is supplied to the V-phase winding 5 (S62).

When the exciting current is supplied to the V-phase winding 5 in S62, the oscillation frequency of the frequency detection circuit 30 using the U-phase and W-phase windings 4 and 6 as elements is detected. It is started (S64). The detection of the oscillation frequency is performed until the switching timing at which it is determined that the winding inductance of the U-phase becomes larger than the winding inductance of the W-phase (W> U → W ≦ U) (S66). If an affirmative determination is made in S66, the switch 50 is switched, and the exciting current is supplied to the U-phase winding 4 (S68).

Next, it is determined whether or not to stop the rotation of the SR motor 1 (S70), and if a positive determination is made (S70).
70: YES), the supply of the exciting current to the U-phase winding 4 is stopped, and the process (S5) ends. If a negative determination is made (S70: NO), S50 to S68 are performed again.
The process up to is repeated.

On the other hand, if the determination in S50 is affirmative (S50: YES), it is determined from which phase windings 4, 5, and 6 the energization current has been started, and if the phase has been started from the U phase. Is from S52 (S72: YES), if it is started from the W phase, from S58 (S74: YES), V
When starting from the phase, from S64 (S74: NO)
This processing (S5) is performed.

In this embodiment, S54, S60, S
In the determination of 66, once the magnitude relationship of the winding inductance L is reversed, the excitation current is supplied to the next phase. However, it is determined that the magnitude relationship has been determined a predetermined number of times (for example, three times). Then, the destination of the excitation current may be switched.

The following effects are obtained by using the rotation control device of the SR motor described above. As in the rotation control circuit 20 of the present embodiment, if the rotational position of the rotor 3 is detected using the result of comparing the oscillation frequencies of the frequency detection circuit 30 having the windings 4, 5, and 6 as elements, the battery BT , The oscillation frequency is not affected by the fluctuation, so that the magnitude relationship can be accurately compared. As a result, the rotational position of the rotor 3 (more specifically, the exciting current should be supplied first) Winding) can always be detected accurately.

Therefore, by using the rotation control circuit 20 of this embodiment, the rotor 3 can be started smoothly regardless of the fluctuation of the voltage value of the battery BT. Further, since the rotation control circuit 20 of the present embodiment detects the rotational position of the rotor 3 without using the mapping data, it is not necessary to provide a storage circuit for storing the mapping data. Therefore, when the rotation control circuit 20 of the present embodiment is used, the size of the rotation control device can be reduced.

As described above, if the oscillation frequency of each of the windings 4, 5, and 6 is detected during stoppage, the rotational position of the rotor 3 can be accurately detected from the magnitude relationship. Windings 4, 5, 6 through which current is applied
Cannot detect the oscillation frequency.

However, in the rotation control circuit 20 of the present embodiment, the other two windings except for the winding of the phase to which the exciting current is applied are applied.
Since the oscillation frequency of the three-phase winding (corresponding to the “non-conducting winding” of the present invention) is detected and the switching timing of the exciting current is detected from the magnitude relationship, the voltage value of the battery BT changes. Even if it detects the exact switching timing,
The destination of the excitation current can be changed smoothly.

Incidentally, the frequency detection circuit 30 and the judgment switching section 40 of this embodiment correspond to the frequency detection means of the present invention.
S16, S20, S2 of the startup process (S1) of the present embodiment
Steps S2, S24, S28, and S32 correspond to the starting winding determination means of the present invention. Rotation processing (S
The processing of S52, S58 and S64 of 5) corresponds to the selection detecting means of the present invention, and the processing of S54, S60 and S66 corresponds to the switching means.

[Brief description of the drawings]

FIG. 1 is an axial sectional view of an SR motor according to an embodiment.

FIG. 2 is a circuit diagram of a drive circuit of the SR motor according to the embodiment.

FIG. 3 is an explanatory diagram for explaining a relationship between a rotational position of a rotor and a change in winding inductance in the SR motor of the present embodiment.

FIG. 4 is an explanatory diagram for explaining a relationship between a rotational position of a rotor and a change in winding inductance for all three phases in the SR motor of the present embodiment.

FIG. 5 is a schematic configuration diagram of a rotation control circuit of the present embodiment.

FIG. 6 is a flowchart of a starting process performed when the SR motor of the present embodiment is started.

FIG. 7 is a flowchart of a rotation process performed when the SR motor of the present embodiment is rotating.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... SR motor, 2 ... stator, 2a ... teeth (salient pole), 2b ... main body, 3 ... rotor, 3a ... salient pole, 3b ... main body, 4, 5, 6 ... winding, 8 ... drive circuit, 9, 10 switches, 11, 12 diodes, 20 rotation control circuit,
Reference numeral 30: frequency detection circuit, 40: comparison switching unit, 50: switch

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) PP04 PP13 PP32 PP33

Claims (6)

[Claims] 1. A stator having a plurality of winding salient poles wound with a winding, a rotor having a plurality of exciting salient poles passing through a position facing the winding salient pole, and detecting a rotational position of the rotor. A rotation control device for controlling the rotation of a switched reluctance motor including excitation current supply means for rotating the rotor by switching a destination of an excitation current supplied to the winding in a predetermined order; An oscillation circuit using a wire as an element is provided for each of the windings,
Frequency detecting means for detecting the oscillating frequency of each of the oscillating circuits, and comparing the oscillating frequencies of the oscillating circuits detected by the frequency detecting means between the oscillating circuits when the switched reluctance motor is started. Starting winding determining means for determining a winding to which the exciting current is to be applied first according to the rotational position of the rotor determined from the magnitude relationship of the oscillation frequencies between the respective oscillation circuits. And a rotation control device. 2. A stator having a plurality of winding salient poles wound with a winding, a rotor having a plurality of exciting salient poles passing through a position facing the winding salient pole, and detecting a rotational position of the rotor. A rotation control device for controlling the rotation of a switched reluctance motor including excitation current supply means for rotating the rotor by switching a destination of an excitation current supplied to the winding in a predetermined order; An oscillation circuit using a wire as an element is provided for each of the windings,
Frequency detecting means for detecting the oscillating frequency of each of the oscillating circuits, while the switched reluctance motor is rotating, a non-energized oscillating circuit having the winding, to which the exciting current is not applied, as an element, Selection detection means for operating the frequency detection means so as to oscillate and detecting the oscillation frequency of the non-conducting oscillation circuit; and among the oscillation frequencies of the non-conduction oscillation circuit detected by the selection detection means, A specified winding is determined by the winding through which the exciting current is applied, and a switching timing at which the magnitude relationship between the oscillation frequencies of the non-conductive oscillation circuit having the specified winding as an element is inverted, and the switching is performed. Switching means for switching a destination of the excitation current at a timing. 3. The rotation control device according to claim 2, wherein, when the switched reluctance motor is a three-phase motor, the designated winding excludes the winding of a phase to which an exciting current is applied. A rotation control device comprising the windings of the other two phases. 4. A stator having a plurality of winding salient poles having windings wound thereon, a rotor having a plurality of exciting salient poles passing through a position facing the winding salient poles, and an excitation energizing the windings. A switched reluctance motor comprising: an excitation current supply unit that switches a current application destination in a predetermined order, detects a rotational position of the rotor, and rotates the rotor. A circuit is provided for each of the windings,
Frequency detecting means for detecting the oscillating frequency of each of the oscillating circuits, and comparing the oscillating frequencies of the oscillating circuits detected by the frequency detecting means between the oscillating circuits when the switched reluctance motor is started. A rotation control device comprising: starting-time winding determining means for determining a winding to which the exciting current is to be applied first according to a rotational position of the rotor determined from a magnitude relationship of the oscillation frequencies between the respective oscillation circuits. The switched reluctance motor characterized by having provided. 5. A stator having a plurality of winding salient poles on which windings are wound, a rotor having a plurality of exciting salient poles passing through positions opposed to the winding salient poles, and an excitation energizing the windings. A switched reluctance motor comprising: an excitation current application unit for detecting a rotation position of the rotor and rotating the rotor by switching a current application destination in a predetermined order, wherein the winding is an element. An oscillation circuit is provided for each of the windings,
Frequency detecting means for detecting the oscillating frequency of each of the oscillating circuits, while the switched reluctance motor is rotating, a non-energized oscillating circuit having the winding, to which the exciting current is not applied, as an element, Selection detection means for operating the frequency detection means so as to oscillate and detecting the oscillation frequency of the non-conducting oscillation circuit; and among the oscillation frequencies of the non-conduction oscillation circuit detected by the selection detection means, A specified winding is determined by the winding through which the exciting current is applied, and a switching timing at which the magnitude relationship between the oscillation frequencies of the non-conductive oscillation circuit having the specified winding as an element is inverted, and the switching is performed. A switched reluctance motor provided with a rotation control device including switching means for switching a destination of the excitation current at a timing. 6. The switched reluctance motor according to claim 5, wherein, when the switched reluctance motor is a three-phase motor, the designated winding excludes the winding of a phase to which an exciting current is applied. And the other two phases of the winding.