JP2001103787A - Switched reluctance motor and rotation controller therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotation controller which makes it possible to detect the rotational position of the rotor of a SR motor with accuracy even if the supply voltage drops. SOLUTION: In the rotation controller, when exciting current is passed in phase U, coil inductance in phase V and that in phase W are detected (S52) and compared with each other (S54). When coil inductance in phase W exceeds that in phase V, the target to which existing current is applied is switched from phase U to phase W (S56). Then coil inductance in phase U and that in phase V are compared with each other, and subsequently coil inductance in phase U is compared with that in phase W. Thus, the target to which exciting current is applied is switched from phase W to phase V to phase U (S58-S68). Since the magnitude of the coil inductance of windings in two phases without exciting current passed is compared to determine exact switching timing, as mentioned above, the target to which exciting current is applied can be smoothly switched.

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 Conventionally, 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 for switching an application destination of an exciting current 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.

Therefore, according to the present invention, the rotational position of the rotor of the switched reluctance motor can be accurately detected even if the power supply voltage for detecting the detected voltage decreases.
Moreover, it is an object to provide a small-scale rotation control device.

[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, detects all detected voltages of a winding detected by voltage detecting means. Comparison between each winding, according to the rotational position of the rotor determined from the magnitude relationship of the detected voltage between each winding,
The winding to which the exciting current is first applied is determined.

According to a fourth aspect of the present invention, there is provided a switched reluctance motor including a rotation control device according to the first aspect, and a winding to which an exciting current is first supplied in the same manner as the rotation control device according to the first aspect. Is determined. Usually, a common power supply (such as a battery of an automobile) is often used as a power supply for applying the detected voltage to the series circuit, and when the power supply voltage changes, the detection voltage is equally affected by the change. It often happens. In such a case, even if the rotational position of the rotor is detected using the reference value (the reference voltage or the like) as in the first and second examples described above, the detection result becomes inaccurate.

However, in the rotation control device according to the first aspect or the rotation control device of the switched reluctance motor according to the fourth aspect, the rotational position of the rotor is detected by using the result of comparing the detection voltages of the windings. Even if the power supply voltage changes and the detection voltage is equally affected, the magnitude relationship between the detection voltages does not change, so the rotational position of the rotor (more specifically, the excitation current should be applied first. Winding) can always be detected accurately.

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 be started smoothly regardless of the fluctuation of the power supply voltage. 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 detected voltage of each winding is detected during stoppage, the rotational position of the rotor can be accurately detected from the magnitude relationship. However, the excitation current is supplied during rotation. The detection voltage cannot be detected from the winding. Therefore, the rotation control device according to claim 2 operates the voltage detection means so that the detected voltage is applied to the non-energized winding to which the exciting current is not applied while the switched reluctance motor is rotating. The detection voltage of the line is detected, and among the detection voltages of the non-energized windings detected by the selection detecting means, the magnitude relation of the detection voltage of the designated winding determined by the winding to which the excitation current is applied is inverted. The switching timing is detected, and the destination of the excitation current is switched at the switching timing.

According to a fifth aspect of the present invention, there is provided a switched reluctance motor including the rotation control device according to the second aspect, wherein the switching timing is detected by the same method as the rotation control device according to the second aspect, and the excitation current is added to the switching timing. Is switched. In the rotation control device according to the second aspect or the switching motor according to the fifth aspect, since the detection voltage of the non-energized winding is detected and the switching timing of the excitation current is detected based on the magnitude relationship, the switching voltage of the excitation current is detected. Even if the voltage value changes, an accurate switching timing can be detected, and the destination of the excitation current can be smoothly changed.

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 with four salient poles 3a protruding in the radial direction on the outer periphery of a main body 3b formed in a cylindrical shape. In this SR motor 1, the rotor 3 is configured such that its rotation axis coincides with the center axis of the main body 2b of the stator 2, and when the rotor 3 is rotated, the salient pole 3a of the rotor 3 The second salient pole 2a passes through a position facing the salient pole 2a. Further, in the SR motor 1, the salient poles 2a of the stator 2 are set every 60 degrees, and
They are arranged at equal intervals every 0 degree.

The SR motor 1 according to the present embodiment is configured as a three-phase motor in which the windings 4, 5, and 6 are wound so that the salient poles 2a opposed to each other have the same phase. Hereinafter, winding 4
Is wound, the phase of the salient pole 2a is called a U phase, the winding 5 is called a V phase, and the winding 6 is called a W phase. The SR motor 1 excites the windings 4, 5, 6 by supplying an exciting current to excite the salient poles 2 a and 3 a
This is a motor that rotates the rotor 3 by utilizing the attraction force due to the magnetic attraction caused by the magnetic saliency.

Using this suction force, the rotor 3 is moved from the U-phase to the V-phase.
The mechanism for rotating in the direction from phase to W phase will be described with reference to the example of FIG. 1. First, since the salient pole 3a is initially (at the time of starting) between the W phase and the V phase, the W-phase winding 6 is excited. Then, the salient pole 3a is drawn toward the W-phase salient pole 2a, and the rotor 3 is rotated in the direction from the V phase to the W phase. Next, the salient pole 3a is a W-phase salient pole 2a.
After moving to the position opposite to
Phase 5 to V-phase 5
The salient pole 3a facing the phase is drawn to the V-phase salient pole 2a, and the rotor 3 is further rotated. When the salient pole 3a comes to a position opposing the salient pole 2a, the application of the exciting current to the winding 6 is completely stopped. The reason is that when the excitation of the winding 5 is continued when the excitation of the winding 6 is started,
This is because the salient pole 3a is attracted to the W phase and the rotor 3 rotates in the reverse direction. Next, when the salient pole 3a comes to a position facing the V-phase salient pole 2a, the U-phase winding 4 is excited, and the salient pole 3a between the W-phase and the V-phase at the time of starting is replaced with the U-phase salient pole. By pulling the rotor 3a, 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 diodes 11, 12
Is provided to regenerate the regenerative current generated when the switches 9 and 10 are turned off to the battery BT.

By the way, in order to operate the SR motor 1 of this embodiment, it is necessary to accurately know whether or not the salient pole 3a has come to the position facing the salient pole 2a while the rotor 3 is rotating as described above. There is. Further, at the time of starting, since it is not known which rotational position of the rotor 3 is, it is necessary to accurately grasp the rotational position of the rotor 3 at the time of starting.

In the following, a method for grasping the rotational position of the rotor 3 will be described, then a rotation control circuit 20 for grasping the rotational position will be described, and a control method for rotating the rotor 3 performed by the rotation control circuit 20 will be described. . First, a method for grasping the rotational position of the rotor 3 will be described.

FIGS. 3A and 3B are axial sectional views of the SR motor 1. FIG. 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.
Is a θ-L graph for describing 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 shows the correspondence between the rotational position of the rotor 3 when the SR motor 1 rotates and the winding inductance L of each phase, and Table 2 shows the rotational position of the rotor 3 when the SR motor 1 starts. 5 is a correspondence table between the winding inductance L of each phase. In the following, U, V, and W simply 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, as viewed in the U-phase, 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. It is known that when the rotor 3 keeps rotating, the winding inductance L takes a minimum value for a while without the two salient poles 2a and 3a being completely aligned, and then rises again in direct proportion.

Looking at all the winding inductances L of the phases that 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. 3), the other two phases (for example, the V phase and the W phase). It was experimentally found that the magnitude relationship of the winding inductance L was reversed (point b).

[0029]

[Table 1]

Therefore, as shown in Table 1, the rotor 3
Is the rotation direction of U-phase → V-phase → W-phase, the winding inductance L of U-phase at the rotation position where the magnitude of the winding inductance L of V-phase and W-phase becomes from V> W to V ≦ W (Peak rotation position at point a), and U> V
, The W-phase winding inductance L becomes maximum (peak rotation position at point e), and W> U is W
At the rotational position where ≦ U, the V-phase winding inductance L is maximized (the peak rotational position at the point f).

On the other hand, between the peak rotation positions, the winding inductance L of any phase (for example, V phase) takes the lowest value, and the winding inductance L of the other two phases (for example, U phase and W phase) It was experimentally found that the magnitude relation did not reverse.

[0032]

[Table 2]

Accordingly, as shown in Table 2, when the magnitude of the winding inductance L is U ≧ W and V> W (section in FIG. 4), one of the protrusions 3a is located between the W phase and the U phase. The other protrusion 3a is located between the W phase and the V phase, and when the magnitude of the winding inductance L is W ≧ V and U> V (FIG. 4).
), One salient pole 3a is between the V phase and the W phase, the other projection 3a is between the V phase and the U phase, and the magnitude of the winding inductance L is V ≧ U and When W> U (section in FIG. 4), one salient pole 3a is between the U phase and the V phase, and the other projection 3a is between the U phase and the W phase.

Next, the rotation control circuit 20 for comparing the winding inductances L of the respective phases to detect the rotational position of the rotor 3 and to determine the windings 4, 5 and 6 for supplying the exciting current will be described. I do. Here, FIG. 5 is a schematic configuration diagram of the rotation control circuit 20, and FIG. 6 is a graph showing a detection voltage generated in the windings 4, 5, and 6 when a voltage is applied to the windings 4, 5, and 6. Note that FIG. 5 shows only the U phase because the configuration of each phase is the same.

As shown in FIG. 5, the rotation control circuit 20 includes a sampling unit 30 for sampling a detection voltage indicating the winding inductance L, a sample and hold unit 40 for sampling and holding the sampled detection voltage, A comparison unit 50 that compares the magnitudes of the detected voltages of the respective phases sampled and held by the sample and hold unit 40 and outputs the comparison result, and a winding to which an excitation current should be applied based on the comparison result output from the comparison unit 50. And a power supply destination specifying unit 60 for specifying the lines 4, 5, and 6. The rotation control circuit 20
Then, an exciting current for exciting the winding 4 is applied between the sample section 30 and the sample hold section 40.
A switch 70 for preventing the inflow to the zero side is provided. The switch 70 is connected to the power supply destination specifying unit 60 and operates according to the instruction of the power supply destination specifying unit 60.

The rotation control circuit 20 includes a drive circuit 8
Connection points α1 to α between the diode 11 and the switch 9
3 (see FIG. 2) corresponds to a detection point A described later, and this point α
They are connected via 1 to α3. First, sample part 3
0, as shown in FIG. 5, an inlet 32 for drawing a voltage from a voltage source such as a vehicle battery to the sample unit 30, and a voltage dividing resistor 34 for dividing the voltage drawn from the inlet 32. , The winding 4 connected in series to the voltage dividing resistor 34
And a switch 10a composed of a switching element connected between the winding 4 and a ground point. Note that a point between the winding 4 and the resistor 34 to which the switch 70 is connected is hereinafter referred to as a detection point A.

In the sample section 30, the switch 10a
Is closed, the detection voltage Vdet at the detection point A is obtained from the resistance value R of the voltage dividing resistor 34 and the winding inductance L of the winding 4.
Is expressed by the following equation 1 using the elapsed time t elapsed since the switch 10a was closed. Here, V
cc is a voltage applied to the inlet 32.

Vdet = Vcc * exp ((− R / L) t) − (1) From the equation (1), since the detection voltage Vdet and the resistance value R of the voltage dividing resistor 34 are constant, the elapsed time t is Constant, ie
The detection voltage Vde after a certain time after closing the switch 10a
If t is detected, it is understood that the detection Vdet and the winding inductance L have a one-to-one relationship, and the winding inductance L can be easily obtained from the detection voltage Vdet.

The voltage sources connected to the inlet 32 are all connected to a common voltage source. Next, the sample hold unit 40 includes an OP amplifier 42 whose non-inverting terminal is connected to the detection point A via the switch 70,
A switch 44 having one terminal connected to the output terminal of the amplifier 42, a capacitor 46 connected to the terminal on the other side of the switch 44 and charged with the voltage at the detection point A, and the other side of the switch 44 This is a general sample-and-hold circuit comprising a non-inverting terminal connected to a terminal of the OP amplifier 42 and a capacitor 46, and a terminal on the inverting terminal side of the OP amplifier 42 and an output terminal connected to a terminal on the inverting terminal side. .

Next, the comparison unit 50 includes three comparators 52,
54 and 56. The comparators 52 and 5
Reference numerals 4 and 56 are connected to the output terminals (specifically, the output terminals of the OP amplifier 48) of any two sample-and-hold units 40 for comparing the detection voltages. Of these, the comparator 52
Connected to the output terminals of the U-phase and the W-phase. The U-phase and the W-phase winding inductances L are compared from the U-phase and the W-phase detection voltages Vdet. If the value is larger than or equal to L (U ≧ W), “1” which is the rotation position information is output from the output terminal, and if it is smaller (U <W), “0” is output. The comparator 54 is connected to the W-phase and V-phase output terminals, and the W-phase winding inductance L is changed to the V-phase winding inductance L.
If it is greater than or equal to (W ≧ V), “1” which is the rotational position information is output from the output terminal, and if it is smaller (W <V).
V) is configured to output “0”. Further, the comparator 56 is connected to the U-phase and W-phase output terminals. When the U-phase winding inductance L is greater than or equal to the W-phase winding inductance L (U ≧ W), the comparator 56 rotates from the output terminal. The position information “1” is output, and if it is small (U
<W) is configured to output “0”.

The rotation control circuit 20 constructed as described above
The operation of will be described. In this embodiment, as shown in FIG. 6, a constant voltage of 2 V is applied to the inlet 32 as the detected voltage. When a detection pulse for instructing the switch 10a to close for a certain period of time from the power supply destination specifying unit 60 (23 μs in the present embodiment) is given to the switch 10a, the winding inductance L of the winding 4 is calculated as in the above-described equation (1). A detection voltage Vdet appears at the point A according to a time constant expressed by the resistance constant of the resistor 34. And the switch 10a
After a predetermined time (after 18 seconds) from closing the switch 44, the switch 44 is closed, the capacitor 46 is charged with the detection voltage Vdet appearing at the point A, sampled and held, and the switch 44 is opened. The detection voltage Vdet when the switch 44 is closed is output. This is because, in the present embodiment, the detection of the detection voltage Vdet is performed with a time lag for each winding.
This is because it is necessary to hold the detected voltage Vdet until the detection voltage Vdet of the winding to be compared is detected.

In this embodiment, the switch 44 is closed 18 μs after the switch 10a is closed.
The control is performed such that the switch 10a is opened at the same time when the switch 10a is opened 5 μs later. The switches 10a, 44
The time to close is applied to this example,
Of course, it may be changed for each embodiment.

The following processing is performed using the rotation control circuit 20 that operates as described above, and will be described.
Note that the detection voltage described below is the detection voltage Vdet described above.
It is. Here, FIG. 7 is a flowchart of a start-time process when the SR motor 1 is started. FIG. 8 is a graph showing the timing of outputting a detection pulse at the time of starting. FIG. 9 is a flowchart of a rotation process when the SR motor 1 is rotating.

First, in order to rotate the SR motor 1, as shown in FIG.
0 is turned on (S10). First, the U-phase rotation control circuit 20 is turned on.
As described above, a sample-and-hold pulse is output to the switch 44 after 18 .mu.s, and the switches 10a and 44 are closed 23 .mu.s after 23 .mu.s after applying the detection pulse to the switch 10a as described above. The detected voltage of the U phase is output to the comparing unit 50 (S12). Thereafter, detection voltages are output for the V phase and the W phase in the same manner as in S12 (S14, S16). Then U
It is determined whether .gtoreq.W and V> W (the output of the comparator 52 is "1" and the output of the comparator 56 is "0") (S18), and if an affirmative determination is made, the exciting current is first supplied to the U-phase. First, the switch 70 of the U-phase rotation control circuit 20 is opened (S
20) Then, an exciting current is applied to the U-phase winding (S2).
2) Output the instruction to be performed, and end this processing.

Next, if a negative determination is made in S18, then W ≧
It is determined whether V and U> V (the output of the comparator 54 is "1" and the output of the comparator 56 is "0") (S24), and if an affirmative determination is made, the exciting current is supplied to the W phase first. Therefore, first, the switch 70 of the W-phase rotation control circuit 20 is opened (S26), and then an exciting current is supplied to the W-phase winding (S2).
8) An instruction to perform is output, and the process ends.

Next, if a negative determination is made in S24, then V ≧
It is determined whether U and W> U (the output of the comparator 56 is "1" and the output of the comparator 52 is "0") (S30), and if an affirmative determination is made, an exciting current is first supplied to the V phase. Therefore, first, the switch 70 of the V-phase rotation control circuit 20 is opened (S32), and thereafter, an exciting current is supplied to the V-phase winding (S3).
4) An instruction to perform is output, and the process ends.

In this process (S1), as shown in FIG. 8, a detection pulse is output to each phase at intervals of about 1,4 ms and for about 4.3 ms, and the windings 4, 5, and 6 are detected. The detection voltage is sampled and held. This is because, in order to accurately detect the position of the rotor 3 at the time of starting the motor, the detection voltage applied to a certain winding completely converges, and another winding is applied to the winding for which the detection voltage is to be detected. This is because the effect of detecting the detection voltage of the winding is not affected.

Also, in this processing, the detection voltage is sampled and held only once, but in S18, S24, S
30 may be repeated to detect a more accurate rotational position of the rotor 3. In this case, after performing the process of repeatedly detecting S18, S24, and S30 a predetermined number of times, the switch 70 determines from which phase the excitation has been started, and determines the switch 70 of any phase.
Can be opened.

Next, a description will be given of a process during rotation when the SR motor 1 is rotating. This rotation process (S5)
Is performed subsequent to the above-described startup processing. When the rotation process (S5) is started, first, as shown in the flowchart of FIG. 9, it is determined whether or not the engine has just started (S50). If a negative determination is made in this determination (S50: NO), the excitation current is first supplied to the U-phase, so that detection of the detection voltages for the V-phase and W-phase is started (S52), and the detected voltages are compared. Until the output of the switch 54 changes from “0” to “1” (switching timing of the present invention), that is, until the W-phase winding inductance becomes larger than the V-phase winding inductance (S54). ). This S
Since the detection of the detection voltage is performed in a very short time of 23 μs as described above,
This is because it is necessary to repeat detection of the detection voltage in order to grasp the W-phase and V-phase winding inductances successively in time. If an affirmative determination is made in S54, an exciting current is supplied to the W phase (S56). At this time (S56), the switch 70 of the W-phase rotation control circuit 20 is opened, and the switch 70 of the U-phase rotation control circuit 20 is closed.

Next, since an exciting current is supplied to the W phase,
The detection of the detection voltages for the U phase and the V phase is started (S5).
8) The detected voltage is changed until the output of the comparator 56 changes from “0” to “1”, that is, until the V-phase winding inductance becomes larger than the U-phase winding inductance.
It is repeatedly detected (S60). If an affirmative determination is made in S60, an exciting current is supplied to the V phase (S6).
2). At this time (S62), the switch 70 of the V-phase rotation control circuit 20 is opened, and the switch 70 of the W-phase rotation control circuit 20 is closed.

Next, since an exciting current is applied to the V phase,
Detection of the detection voltages for the U phase and the W phase is started (S6).
4) The detected voltage is changed until the output of the comparator 52 changes from “0” to “1”, that is, until the U-phase winding inductance becomes larger than the W-phase winding inductance.
It is repeatedly detected (S66). If an affirmative determination is made in S66, an exciting current is supplied to the V phase (S6).
8). At this time (S68), the switch 70 of the U-phase rotation control circuit 20 is opened, and the switch 70 of the V-phase rotation control circuit 20 is closed.

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), stopping the supply of the exciting current to each phase,
This processing (S5) ends. In addition, a negative determination (S70:
If NO), the processes from S50 to S68 are repeated again.

On the other hand, if an affirmative determination is made in S50 (S50: YES), it is determined from which phase the energizing current has been started.
From step 52 (S72: YES), when the process is started from the W phase, the process is performed from S58 (S74: YES), and when the process is started from the V phase, the process is performed from S64 (S74: NO).

In this embodiment, S54, S60, S
In the judgment of 66, once the magnitude relation of the winding inductance is reversed, the exciting current is supplied to the next phase. However, if it is determined that the magnitude relation has been determined a predetermined number of times (for example, three times). Next, energization to the phase to which the excitation current is to be energized may be started.

The use of the above-described SR motor rotation control device has the following effects. In the rotation control device 20 of the present embodiment, the rotational position of the rotor 3 is detected by using the result of comparing the detection voltages of the windings 4, 5, and 6, and the detection is performed by changing the power supply voltage of the battery BT. Even if the voltage is equally affected, the magnitude relationship of the detected voltages does not change, so that the rotational position of the rotor 3 (more specifically, the windings 4, 5, and 6 to which the exciting current is first applied) is always set. Can be detected accurately.

Therefore, by using the rotation control device 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 device 20 of the present embodiment detects the rotation position of the rotor without using the mapping data, it is not necessary to provide a storage circuit for storing the mapping data. Therefore, when the rotation control device 20 of the present embodiment is used, the size of the rotation control device can be reduced.

As described above, if the detection voltages of the windings 4, 5, and 6 are detected during stoppage, the rotational position of the rotor can be accurately detected from the magnitude relationship. No detection voltage can be detected from the windings 4, 5 and 6 to which the current is supplied. However, in the rotation control device 20 of the present embodiment, the detection of the other two phase windings (corresponding to the “non-energized winding” of the present invention) except for the winding of the phase to which the exciting current is applied. Since the voltage is detected and the switching timing of the exciting current is detected based on the magnitude relationship, even if the voltage value of the battery BT changes, the accurate switching timing is detected and the destination of the exciting current can be smoothly switched. Can be replaced.

The sample section 30 of this embodiment corresponds to the voltage detecting means of the present invention. Start-up processing (S
S18, S22, S24, S26, S30, S3 of 1)
The processing of No. 4 corresponds to the starting winding determination means of the present invention.
S52, S58, S6 of the rotation process (S5) of the present embodiment.
The processing of No. 4 is performed by the selection detecting means of the present invention in S54, S60,
The process of S66 corresponds to a switching unit.

[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 circuit diagram of a rotation control circuit according to the present embodiment.

FIG. 6 is an explanatory diagram for explaining a detection voltage according to the present embodiment.

FIG. 7 is a flowchart of a start-time process performed when the SR motor of the present embodiment is started.

FIG. 8 is an explanatory diagram for explaining a timing of detecting a detection voltage according to the present embodiment.

FIG. 9 is a flowchart of a rotation process performed when the SR motor according to 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: sample part, 32: inlet, 34: voltage dividing resistance, 4
0: sample hold unit, 42, 48: OP amplifier, 4
4 switches, 46 capacitors, 50, 52, 54
Comparison section, 56 ... Comparator, 60 ... Power supply destination designation section, 70 ... Switch

Continued on the front page (72) Inventor Masami Fujitsuna 1-1-1 Showa-cho, Kariya-shi, Aichi F-term in DENSO Corporation (reference) 5H550 BB08 CC04 DD09 FF01 GG06 HA01 HA04 LL21 LL23 MM15

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 comprising excitation current supply means for rotating the rotor by switching the destination of the excitation current supplied to the windings in a predetermined order; Voltage detection means for detecting a detection voltage generated in each winding as a result of applying a voltage to be detected to a series circuit in which a resistor is connected in series to a line; and when the switched reluctance motor is started, the voltage detection means detects the detection voltage. All the detected voltages of the windings are compared between the windings, and the exciting current is determined according to the rotational position of the rotor determined from the magnitude relationship of the detected voltages between the windings. Rotation control apparatus; and a starting winding determination means for determining the winding should be initially energized. 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 comprising excitation current supply means for rotating the rotor by switching the destination of the excitation current supplied to the windings in a predetermined order; Voltage detection means for detecting a detection voltage generated in each of the windings as a result of applying a voltage to be detected to a series circuit in which a resistor is connected in series to a wire; and wherein the excitation current is supplied during rotation of the switched reluctance motor. Selection detecting means for operating the voltage detecting means so as to apply the detected voltage to the non-conducting winding, and detecting the detection voltage of the non-conducting winding; Among the detection voltages of the non-conducting windings detected by the means, the switching timing at which the magnitude relationship between the detection voltages of the designated windings determined by the windings to which the exciting current is being conducted is inverted is detected. A switching unit for switching a destination of the excitation current at the switching 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. In a switch reluctance motor including an excitation current supply unit that switches a current application destination in a predetermined order, detects a rotation position of the rotor, and rotates the rotor, a resistor is serially connected to each of the windings. Voltage detection means for detecting a detection voltage generated in each of the windings as a result of applying the detected voltage to the connected series circuit; and all of the windings detected by the voltage detection means when the switched reluctance motor is started. The respective detection voltages are compared between the windings, and the exciting current should be applied first according to the rotational position of the rotor determined from the magnitude relationship of the detection voltages between the windings. Switched reluctance motor, characterized in that a rotation control device comprising a starting winding determination means for determining a line. 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. In a switched reluctance motor including an excitation current supply applying unit that switches a current application destination in a predetermined order, detects a rotational position of the rotor, and rotates the rotor, a resistor is serially connected to each of the windings. Voltage detection means for detecting a detection voltage generated in each winding as a result of applying a voltage to be detected to a series circuit connected to the series circuit; and a non-energized winding to which the excitation current is not applied during rotation of the switched reluctance motor. Selection detection means for operating the voltage detection means to detect the detection voltage of the non-conducting winding so that the detected voltage is applied to the detection voltage; Among the detection voltages of the non-energized windings, a switching timing at which the magnitude relationship between the detection voltages of the designated windings determined by the windings to which the excitation current is applied is inverted is detected, and the excitation timing is determined at the switching timing. A switched reluctance motor provided with a rotation control device including switching means for switching a current supply destination. 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.