WO2008026639A1

WO2008026639A1 - Method for controlling reluctance motor

Info

Publication number: WO2008026639A1
Application number: PCT/JP2007/066772
Authority: WO
Inventors: Tetsuo Nakata; Atsushi Suhara; Yasuto Yanagida
Original assignee: Daikin Industries, Ltd.
Priority date: 2006-08-31
Filing date: 2007-08-29
Publication date: 2008-03-06
Also published as: JP2008061378A

Abstract

Provided is a method for controlling a reluctance motor, by which reluctance torque is increased. In the method, first to sixth controls are performed. In the first control, a current is permitted to flow only in a first coil (121). In the second control, a current is permitted to flow only in a second coil (122). In the third control, a current is permitted to flow only in a third coil (123). In the fourth control, a current is permitted to flow only in the first coil (121) and the second coil (122). In the fifth control, a current is permitted to flow only in the second coil (122) and the third coil (123). In the sixth control, a current is permitted to flow only in the third coil (123) and the first coil (121). The control wherein a maximum reluctance torque (T) is generated is selected for a reluctance motor (1) for every rotating angle (ϑ) of a rotor (11), from among the first to the sixth controls and performed.

Description

Specification

Reluctance motor control method

Technical field

The present invention relates to a method for controlling a reluctance motor.

Background art

[0002] A reluctance motor that is driven by passing a three-phase current has been proposed as a motor that can obtain a large torque at a low current and is easy to downsize.

[0003] The reluctance motor includes a stator having a plurality of windings through which currents of respective phases flow, and a rotor provided to face the stator. The rotor rotates by executing control (single-phase excitation) in which the current of each phase is switched in order in the stator. However, with such control, it has been difficult to increase the reluctance torque generated in the reluctance motor.

[0004] Therefore, by adopting control (two-phase excitation) that allows two-phase currents to flow in parallel among the three-phase currents, the control is executed by sequentially switching between the one-phase excitation and the two-phase excitation. Technologies that increase reluctance torque have been proposed.

[0005] Techniques related to the present invention will be described below.

[0006] Patent Document 1: Japanese Unexamined Patent Publication No. 2000-295891

Patent Document 2: JP 2001-157490 A

Disclosure of the invention

Problems to be solved by the invention

[0007] However, the reluctance torque may not be increased simply by sequentially switching between 1-phase excitation and 2-phase excitation.

[0008] The present invention has been made in view of the above-described circumstances, and is intended to increase the reluctance torque.

Means for solving the problem

[0009] The first aspect of the method for controlling the reluctance motor according to the present invention is that it can rotate about a predetermined axis (91) and is only on one of its outer peripheral side and inner peripheral side. Sudden A magnetic rotor (11) having a plurality of protruding portions (111), a plurality of first windings (121) through which a u-phase current flows, and a second winding (through which a V-phase current flows) 122) and a plurality of third windings (123) through which a W-phase current flows, and a stator (12) provided facing the rotor from the one side. The first to third windings are arranged in this order with respect to the reluctance motor (1) repeatedly arranged along the circumferential direction (92) around the predetermined axis. A first control for flowing the current only in the wire, a second control for flowing the current only in the second winding, and a third control for flowing the current only in the third winding; A fourth control for flowing the current only in the first and second windings; a fifth control for flowing the current only in the second and third windings; To the first winding From among the control of the sixth flowing the current, the resulting reluctance torque (T) is executed is one selected for each rotation angle of the control force the rotor having the maximum (theta)

Yes

[0010] A second aspect of the reluctance motor control method according to the present invention is the reluctance motor control method according to the first aspect, wherein the first to sixth controls are the The sixth control, the first control, the fourth control, the second control, the fifth control, and the third control are executed in this order, and the sixth control to the first control are executed. The rotation angle (D2) to be switched to is the rotation angle (Θ 4) when the reluctance torque (T) generated by the sixth control is maximum, and immediately after the sixth control. The rotation angle (Θ 1) when the reluctance torque generated by the first control to be executed is maximized is selected, and switching from the fourth control to the second control is performed. The rotation angle (D4) is the reluctance generated by the fourth control. The rotation angle when the torque (T) becomes maximum and the rotation when the reluctance torque generated by the second control executed immediately after the fourth control becomes maximum. The rotation angle (D6) selected between the fifth control and the third control is selected between the reluctance torque (T) generated by the fifth control and the angle (Θ2). The rotation angle (Θ 6) when the maximum reluctance torque generated by the third control executed immediately after the fifth control and the rotation angle (Θ 3) when the maximum reluctance torque occurs. Is selected.

[0011] The third aspect of the control method of the reluctance motor according to the present invention relates to the second aspect. The reluctance motor control method, wherein the rotor (11) includes eight portions (111), and the stator (12) includes the first to third windings (121; 123), and the rotation angle (D) that is executed for the reluctance motor (1) and the switching is performed.

2, D4, D6), the rotation angle (Θ) when the portion (111) is located in the middle of the adjacent windings (121 to 123) in the circumferential direction (92) is 0 ° 3.75 ° or more

3. Selected within the range of 75 ° or less.

The invention's effect

[0012] According to the first aspect of the control method of the reluctance motor according to the present invention, even in the range of the rotation angle where it is difficult to increase the reluctance torque only by the first to third controls, the fourth to fourth The reluctance torque can be increased by selectively executing the sixth control. Therefore, the output of the reluctance motor is increased.

[0013] According to the second or third aspect of the control method of the reluctance motor according to the present invention, the rotation angle when the reluctance torque generated by the first to third controls is maximized is determined in the circumferential direction. The rotation angle deviates from the rotation angle when the part is located in the middle between adjacent windings. On the other hand, the rotation angle when the reluctance torque generated by the fourth to sixth controls is maximized is greater than the rotation angle when the portion is positioned in the middle between adjacent windings in the circumferential direction. Shift in the opposite direction. Therefore, the rotation angle when switching from the sixth control to the first control is selected between the rotation angles when the reluctance torque generated by the sixth and first controls is maximized. The ability to improve reluctance Tonlek. By selecting the rotation angle when switching from the 4th control to the 2nd control, and the rotation angle when switching from the 5th control to the 3rd control are performed in the same way, The reluctance torque can be improved.

[0014] The objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description and the accompanying drawings.

Brief Description of Drawings

FIG. 1 is a diagram conceptually showing a reluctance motor 1 that is effective in the present invention.

FIG. 2 is a diagram showing a change in reluctance torque T with respect to a rotation angle Θ.

FIG. 3 is a diagram showing a change in reluctance torque T with respect to a rotation angle Θ. FIG. 4 is a diagram showing a change in reluctance torque T with respect to a rotation angle Θ.

FIG. 5 is a diagram showing the change of the reluctance torque に対する with respect to the rotation angle Θ.

FIG. 6 is a diagram showing the change of the reluctance torque Τ with respect to the current value.

FIG. 7 is a circuit diagram conceptually showing a control unit 2.

FIG. 8 is a diagram conceptually showing the control of the control unit 2.

BEST MODE FOR CARRYING OUT THE INVENTION

[0016] 1. Structure of reluctance motor

FIG. 1 conceptually shows a reluctance motor 1 that is effective in the present invention. Reluctance motor 1

The rotor 11 and the stator 12 are provided.

The rotor 11 is a magnetic body that can rotate around a predetermined shaft 91 and has a plurality of portions 111 that protrude only on the outer peripheral side of the rotor 11. In FIG. 1, eight portions 111 are provided.

The stator 12 has a plurality of first windings 121, a plurality of second windings 122, and a plurality of third windings 123, and from the outer peripheral side with respect to the rotor 11. Opposed. In Fig. 1, first through third winding force pairs are provided!

The first to third windings 121 to 123 are repeatedly arranged in this order around the predetermined axis 91 along the circumferential direction 92.

[0020] A U-phase current force S flows through the first winding 121, a V-phase current force S flows through the second winding 122, and a W-phase current flows through the third winding 123. The flow directions of the currents flowing in the adjacent windings 12;! To 123 in the circumferential direction 92 are different from each other when viewed from the inner circumferential side to the outer circumferential side.

[0021] This will be specifically described with reference to FIG. In Fig. 1, for U phase, V phase, and W phase currents flowing in the direction opposite to the clockwise direction when viewed from the inner circumference side to the outer circumference side are denoted by U, V, and W, respectively. Show. On the other hand, currents flowing in the clockwise direction when viewed from the inner circumference side to the outer circumference side are indicated by symbols U ′, V ′, and W ′ (hereinafter referred to as U ′ phase and V ′ phase, respectively). And W 'phase current). In each of the first to third windings repeatedly arranged in order along the circumferential direction 92, the currents of the U phase, the V ′ phase, the W phase, the U ′ phase, the V phase, and the W ′ phase are present. Each is washed away. [0022] The rotor 11 may be a magnetic body having a plurality of portions 111 protruding only on the inner peripheral side of the rotor 11. In this case, the stator 12 is provided to face the rotor 11 from the inner peripheral side.

[0023] Hereinafter, a control method for the reluctance motor shown in FIG. 1 will be described.

2. Control method of reluctance motor

In the method for controlling a reluctance motor according to the present invention, the first to sixth controls are executed. First, each of the first to sixth controls will be described.

In the first control, a current flows only through the first winding 121. In the second control, a current flows only through the second winding 122. In the third control, current flows only through the third winding 123. The first to third controls are commonly called “one-phase excitation”.

In the fourth control, a current is allowed to flow in parallel only through the first winding 121 and the second winding 122. In the fifth control, a current flows only in the second winding 122 and the third winding 123 in parallel. In the sixth control, a current is allowed to flow in parallel only through the third winding 123 and the first winding 121. The fourth to sixth controls are commonly called “two-phase excitation”!

FIG. 2 shows changes in the reluctance torque T generated in the reluctance motor 1 with respect to the rotation angle Θ using graphs 101 to 103. A graph 101 shows a case where only the first control is executed. A graph 102 shows a case where only the second control is executed. Graph 103 shows a case where only the third control is executed.

[0028] Here, the relationship between the rotational position of the rotor 11 and the rotational angle Θ is as follows. When the rotation angle Θ is 0 °, a certain portion 111 is located between the adjacent first winding 121 and second winding 122 in the circumferential direction 92. When the rotation angle Θ force is 15 °, a certain portion 11 1 force is positioned in the middle of the second winding 122 and the third winding 123 adjacent in the circumferential direction 92. When the rotation angle Θ force is ¾0 °, a certain portion 111 is located in the middle between the third winding 123 and the first winding 121 adjacent in the circumferential direction 92. The same applies to Fig. 3 described later.

[0029] The reluctance torque represented by the graph 101 has a period of 45 ° with respect to the rotation angle Θ. This is because each time the rotor 11 rotates 45 °, the portion 111 and the first winding 121 face each other. Power. Similarly, the reluctance torque represented by the graphs 102 and 103 has a period of 45 ° with respect to the rotation angle Θ.

[0030] In the graph 101, the reluctance torque T is maximized when the rotation angle Θ is an angle θ 1 deviating from 0 ° in the rotation direction. In the graph 102, the reluctance torque T becomes maximum when the rotation angle Θ force 15 ° is the angle Θ 2 in which the force is also shifted in the rotation direction. In the graph 103, the reluctance torque T becomes maximum when the rotation angle Θ force ¾0 ° force and the angle Θ 3 deviated in the rotation direction. The phase difference ΔΘ 1 and the phase difference ΔΘ 2 between the reluctance torque represented by the graph 102 and the reluctance torque represented by the graph 103 are about 15 °, respectively.

FIG. 3 shows changes of the reluctance torque T generated in the reluctance motor 1 with respect to the rotation angle Θ as graphs 20; A graph 201 shows a case where only the fourth control is executed. A graph 202 shows a case where only the fifth control is executed. Graph 203 shows a case where only the sixth control is executed.

[0033] In each of the reluctance torques represented by the graph 20;! To 203, similarly to the graphs 101 to 103, the rotation angle Θ has a period of 45 °. In the graph 203, the reluctance torque T is maximum when the rotation angle Θ is an angle Θ4 deviating from 0 ° in the direction opposite to the rotation direction. In the graph 201, the reluctance torque T becomes maximum when the rotation angle Θ force 5 ° is also an angle Θ 5 in which the force is shifted in the direction opposite to the rotation direction. In the graph 202, the reluctance torque T is maximized at an angle Θ 6 deviating from the rotational angle Θ force ¾0 ° in the direction opposite to the rotational direction. The phase difference ΔΘ 3 and the phase difference ΔΘ 4 between the reluctance torque represented by the graph 201 and the reluctance torque represented by the graph 202 are about 15 °, respectively.

[0035] Next, in the control method of the reluctance motor according to the present invention, the relationship between the first to sixth controls will be described.

[0036] The control method of the force / reluctance motor is such that the reluctance motor 1 has a control force that maximizes the reluctance torque T generated from among the first to sixth controls. One is selected for each rotation angle Θ.

[0037] This will be specifically described with reference to FIG. FIG. 4 shows graphs 101 to 103 by a one-dot chain line, graphs 20;! To 203 by a broken line, respectively, and the reluctance torque T generated when the reluctance motor control method is executed according to the present invention. A graph 301 showing a change with respect to the rotation angle Θ is shown by a solid line.

[0038] First, the first to sixth controls are respectively executed in advance to measure the reluctance streak T with respect to the rotation angle Θ (graphs 101 to 103; 103, 20;! To 203).

[0039] Then, by comparing graphs 101 to 103, 20;! To 203, one of the first to sixth controls that maximizes the reluctance torque T is selected for each rotation angle Θ. And execute.

That is, when the rotation angle Θ is in the range of the angles D1 to D2, the reluctance torque T represented by the graph 203 is maximized, so the sixth control is selected and executed. When the rotation angle Θ is in the range of the angles D2 to D3, the reluctance torque T represented by the graph 101 is maximized, so the first control is selected and executed. When the rotation angle Θ is in the range of angles D3 to D4, the reluctance torque T represented by the graph 201 is maximized, so the fourth control is selected and executed. When the rotation angle Θ is in the range of the angles D4 to D5, the reluctance torque T represented by the graph 102 is maximized, so the second control is selected and executed. When the rotation angle Θ is in the range of angles D5 to D6, the reluctance torque T represented by the graph 202 is maximized, and therefore the fifth control is selected and executed. When the rotation angle Θ is in the range of the angles D6 to D7, the reluctance torque T represented by the graph 103 is maximized, so the third control is selected and executed.

[0041] According to the force control method, the fourth to sixth controls are selectively executed even in the range of the rotation angle Θ where it is difficult to increase the reluctance torque T by only the first to third controls. By doing this, you can increase the reluctance strength. Therefore, the output of the reluctance motor 1 is increased.

[0042] This will be specifically described with reference to FIG. FIG. 5 shows a graph 301 and a graph 302. A graph 302 represents a change of the reluctance torque T generated when only the first to third controls are executed with respect to the rotation angle Θ. According to the graph 302, the rotation angle Θ is in the range of the angles D1 to D2, the range of the angles D3 to D4, and the range of the angles D5 to D6 only by the first to third controls. It can be seen that the reluctance torque T cannot be increased.

[0043] However, by executing the power control method according to the present invention, the rotation angle Θ is in the range of angles D1 to D2, the range of angles D3 to D4, and the range of angles D5 to D6. However, the reluctance torque T can be increased by comparing the force graph 301 and the graph 302.

In the control method described above, switching from the sixth control to the first control is executed when the rotation angle Θ is the angle D2. Also, when the rotation angle Θ is the angle D4, switching from the fourth control to the second control is executed, and when the rotation angle Θ is the angle D6, switching from the fifth control to the third control is performed. Executed. This content can be grasped as follows.

That is, the angle D2 is an angle at which the reluctance torque T generated by the sixth control is maximized.

It is selected between Θ 4 and the angle θ 1 when the reluctance torque T generated by the first control executed immediately after the sixth control is maximized. The angle D4 is the angle at which the reluctance torque T generated by the fourth control is maximized, Θ5, and the reluctance torque T generated by the second control executed immediately after the fourth control is maximized. It is selected between Θ2. The angle D6 is an angle Θ6 at which the reluctance torque T generated by the fifth control is maximized, and an angle Θ6 at which the reluctance torque T generated by the third control executed immediately after the fifth control is maximized. 3 is selected.

[0046] In particular, in the case of the reluctance motor 1 shown in FIG. 1, that is, the rotor 11 has eight portions 111, and the stator 12 has four sets of first to third windings 12; In this case, it is desirable to select each of the angles D2, D4, and D6 as follows. That is, the angle D2 is selected in the range of 3.75 ° or more and 3.75 ° or less with reference to the rotation angle Θ of 0 ° (0 °). The angle D4 is selected in the range of -3.75 ° to 3.75 °, with the rotation angle Θ force of 15 ° as the reference (0 °). Angle D6 is selected in the range of 3.75 ° or more and 3.75 ° or less with reference to the rotation angle Θ of 30 ° (0 °).

FIG. 6 shows changes in the reluctance torque T with respect to the values of the currents flowing through the first to third windings, using graphs 40;! -403. A graph 401 shows a case where the control method according to the present invention is executed. A graph 402 shows a case where only the first to third controls (one-phase excitation) are executed. Graph 403 shows the case where only the fourth to sixth controls (two-phase excitation) are executed.

[0048] By comparing the graph 401 with the graphs 402 and 403, the control method according to the present invention is executed. Thus, it can be seen that at any current value, the reluctance torque T can be increased more than when only one-phase excitation is performed or when only two-phase excitation is performed.

[0049] The reluctance motor control method described above is performed when the number A1 of the portion 111 and the number A1 of the first to third windings A2 are (Al, A2) = (8, 4) (Fig. 1). However, the present invention can be applied to a reluctance motor having other combinations.

[0050] 3. Reluctance motor controller

FIG. 7 conceptually shows the control unit 2 that controls the reluctance motor 1. The control unit 2 includes input terminals 241 and 242, output terminals 211, 212, 221, 222, 231 and 232, switches S 1 to S 6, and diodes Di;! To Di 6. In Fig. 7, the DC power supply that supplies power to control unit 2

V is also shown.

The switches S 1, S3 and S5 are connected between the output terminals 211, 221 and 231 and the human power terminal 241 respectively. The switches S2, S4, and S6 are connected between the output terminals 212, 222, and 232 and the input terminal 242 respectively. FIG. 1 shows a case where a transistor is employed for each of the switches S1 to S6.

In each of the diodes Dil, Di3, and Di5, the force sword is connected to the output terminals 211, 221, and 231 and the anode is connected to the input terminal 242. The diodes Di2, Di4, and Di6 each have an anode connected to the output terminals 212, 222, and 232, and a force sword connected to the input terminal 241.

[0053] The control unit 2 is connected to the DC power supply V and the first to third windings 121 to 123 as follows. The DC power source V is connected between the input terminals 241 and 242. The first winding 121 is connected between the output terminals 211 and 212. The second winding 122 is connected between the output terminals 221 and 222. The third winding 123 is connected between the output terminals 231 and 232.

FIG. 8 conceptually shows the control of the control unit 2. Such control is based on “2. Control method of reluctance motor” described above. Specifically, when the rotation angle Θ is in the range of the angles D1 to D2, turning on the switches SI and S2 and the switches S5 and S6 respectively causes the first winding 121 and the third winding 123 to turn on. Only flow current (sixth control). When the rotation angle Θ is in the range of D2 to D3, turning on each of the switches SI and S2 allows a current to flow only through the first winding 121 (first control). [0055] When the rotation angle Θ is in the range of D3 to D4, by turning on each of the switches SI and S2 and the switches S3 and S4, current flows only in the first winding 121 and the second winding 122. (4th control). When the rotation angle Θ is in the range of D4 to D5, by turning on each of the switches S3 and S4, a current flows only through the second winding 122 (second control).

[0056] When the rotation angle Θ is in the range of D5 to D6, by turning on each of the switches S3 and S4 and the switches S5 and S6, the current flows only in the second winding 122 and the third winding 123. (5th control). When the rotation angle Θ is in the range of D6 to D7, turning on each of the switches S5 and S6 allows a current to flow only through the third winding (third control).

The present invention has been described in detail. The above description is illustrative in all aspects, and the present invention is not limited thereto. It is understood that the myriad variations S that are not illustrated can be assumed without departing from the scope of the present invention.

Claims

The scope of the claims

[1] A magnetic rotor (rotating around a predetermined axis (91) and having a plurality of portions (111) protruding only on one of its outer peripheral side and inner peripheral side ( 11) and

A plurality of first windings (121) through which a U-phase current flows, a plurality of second windings (122) through which a V-phase current flows, and a third winding (123) through which a W-phase current flows A stator (12) provided opposite to the rotor from the one side;

With

The first to third windings are arranged in this order with respect to the reluctance motor (1) repeatedly arranged along the circumferential direction (92) around the predetermined axis.

A first control for flowing the current only through the first winding;

A second control for flowing the current only through the second winding;

A third control for flowing the current only through the third winding;

A fourth control for flowing the current only through the first and second windings;

A fifth control for passing the current only through the second and third windings;

A sixth control for passing the current only through the third and first windings;

A reluctance motor control method that is selected and executed for each rotation angle (Θ) of the rotor.

[2] The first to sixth controls include the sixth control, the first control, the fourth control, the second control, the fifth control, and the third control. Are executed in the order

The rotation angle (D2) when switching from the sixth control to the first control is the rotation angle (T2) when the reluctance torque (T) generated by the sixth control is maximum. Θ 4) and the rotation angle (Θ 1) when the reluctance torque generated by the first control executed immediately after the sixth control is maximized, The rotation angle (D4) when switching from the control to the second control is the rotation angle (Θ 5) when the reluctance torque (T) generated by the fourth control is maximized. And the rotation angle (Θ 2) when the reluctance torque generated by the second control executed immediately after the fourth control is maximized, and from the fifth control to the second The rotation angle when switching to control 3 is performed (D6) Are the rotation angle (Θ 6) when the reluctance torque (T) generated by the fifth control is maximum, and the reluctance generated by the third control executed immediately after the fifth control. The reluctance motor control method according to claim 1, wherein the control method is selected between the rotation angle (Θ3) when the torque is maximum.

[3] The rotor (11) has eight parts (111),

The stator (12) is implemented for the reluctance motor (1) having four sets of the first to third windings (121 to 123),

The rotation angle (D2, D4, D6) when the switching is performed is! / In the circumferential direction (92), and the portion (111) of the adjacent windings (121-123) 3. The method of controlling a reluctance motor according to claim 2, wherein the rotation angle (Θ) when positioned in the middle is selected from a range of 3.75 ° to 3.75 °, where 0 °.