JPH11318063A - Reluctance motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reluctance motor which is able to reduce a motor width without increasing the iron loss. SOLUTION: Stator windings CU1, CV1, CW1 are wound to energizing poles U1, U2, V1, V2, W1, W2 of each phase of a stator yoke 1. At this time, the stator windings CU1, CV1, CW1 are wound so as to have a part generated where magnetic flux is not inverted on the stator yoke 1 and current direction is set to the stator windings CU1, CV1, CW1. Since iron losses such as hysteresis loss and eddy current loss is small at the part where the magnetic flux of the stator yoke 1 is not inverted, iron losses will hardly increase even if the width of this part is set small to increase the magnetic flux density. As a result, the motor width ca be set small without increasing the iron loss. In addition, when the width of the part where the magnetic flux of the stator yoke is inverted is enlarged, the magnetic flux density of this part is reduced so that the motor efficiency can be improved without the increase in the overall size of the motor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reluctance motor.

[0002]

2. Description of the Related Art Conventionally, a reluctance motor having a structure shown in FIG. 3 is known. FIG. 3 shows a three-phase reluctance motor. The reluctance motor includes a stator and a rotor (not shown) disposed inside the stator. The stator includes a stator yoke 50,
The excitation poles U51, U52 formed on the stator yoke 50,
V51, V52, W51 and W52. Each excitation pole is formed to protrude inward at intervals of 60 degrees. The rotor has four salient poles formed to project outward at 90-degree intervals. Opposing surfaces of the excitation pole of the stator and the salient poles of the rotor are formed in an arc shape centered on the rotation center of the rotor. Also, the excitation poles U51 and U52, V51 and V52, W51 and W5 opposed to each other with the rotor interposed therebetween.
A coil is wound around 2 to form stator windings CU51, CV51, CW51 of each phase U, V, W. That is, the U- terminal is connected to the U-
By winding a coil around the terminal, the U-phase stator winding C
U51 is formed, and the excitation poles V51, V52
A V-phase stator winding CV51 is formed by winding a coil around the V- terminal through the
The W-phase stator winding CW51 is formed by winding a coil through the W51 and W52. In FIG. 3, the mark “x” indicates that the winding is wound in the direction from the top to the bottom of the paper, and the mark “・” indicates that the winding is wound in the direction from the bottom to the top of the paper. Hereinafter, such a conventional connection method is referred to as symmetric connection. Then, by connecting each of the stator windings CU51 to CW51 to a DC power source sequentially by a switching element or the like, that is, by unipolar driving, an attractive force acts on the salient poles of the rotor closest to the excited excitation pole. Then, the rotor rotates. In the conventional reluctance motor, since the stator windings are wound in a symmetrical connection, when the stator windings CU51 to CW51 are unipolarly driven, the stator yoke 50 has arrows u, v, and v in FIG. A magnetic flux as shown by w is formed. In addition,
Magnetic fluxes indicated by arrows u, v, and w in FIG. 3 are magnetic fluxes generated when the U-phase stator winding CU51, the V-phase stator winding CV51, and the W-phase stator winding CW51 are excited. is there.

[0003]

As shown in FIG. 3, the conventional reluctance motor is a unipolar drive, but the stator windings are symmetrical so that a rotating magnetic field is generated by exciting the stator windings. Due to the type connection, the magnetic flux density in each portion of the stator yoke is substantially uniform on average over time, and the manner of magnetic flux change is also uniform. on the other hand,
When the magnetic flux generated in the stator yoke is saturated, iron loss (hysteresis loss, eddy current loss, etc.) increases, and motor efficiency deteriorates. For this reason, in the conventional reluctance motor, the width of each portion of the stator yoke must be determined so as not to be saturated by the magnetic flux generated by the excitation of the stator winding, and there is a limit in reducing the motor width. Was. The present invention has been made in order to solve such a problem,
An object of the present invention is to provide a reluctance motor capable of reducing a motor width without increasing iron loss.

[0004]

In order to solve the above-mentioned problems, the present invention is directed to a stator having a plurality of excitation poles on which a stator yoke and a stator winding are wound, and a rotating motor. A reluctance motor comprising: a stator winding wound around the exciting poles so that a portion of the stator yoke where the direction of the magnetic flux formed by exciting the stator winding is not reversed is generated. And a reluctance motor in which the width of the stator yoke at the portion where the direction of the magnetic flux is not reversed is smaller than the width of the portion where the direction of the magnetic flux is reversed. With the use of the reluctance motor according to the first aspect, the width of the portion where the magnetic flux of the stator yoke does not reverse can be reduced, so that the motor width can be reduced without increasing iron loss. Further, since the width of the portion other than the portion where the direction of the magnetic flux of the stator yoke does not reverse can be increased, the motor efficiency can be improved without increasing the size of the entire motor.

[0005]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing one embodiment of a reluctance motor of the present invention. FIG. 1 shows a three-phase reluctance motor. The reluctance motor includes a stator and a rotor (not shown) disposed inside the stator. The stator includes stator yoke 1 and 60
Excitation poles U1, U2,
V1, V2, W51, and W52. The rotor is
It has four salient poles projecting outward at 90 degree intervals. Opposing surfaces of the excitation pole of the stator and the salient poles of the rotor are formed in an arc shape centered on the rotation center of the rotor. Also, the excitation pole U1 facing the rotor with the rotor interposed therebetween.
And coils are wound around U2, V1 and V2, W1 and W2, and the stator windings CU1, CV1 and C of the respective phases U, V and W are wound.
W1 is formed. Here, the reluctance motor of the present invention has a winding direction and a stator winding C of the stator windings CU1 and CV1 with respect to the excitation poles U1, U2 and V1, V2.
The direction of the current supplied to U1 and CV1 is the direction of the winding of the stator windings CU51 and CV51 with respect to the excitation poles U51, U52 and V51 and V52 of the conventional reluctance motor, and the direction of the current supplied to the stator windings CU51 and CV51. But the stator windings C for the excitation poles W1, W2
The winding direction of W1 and the direction of the current supplied to the stator winding CW1 are different from those of the conventional reluctance motor. Hereinafter, such a connection method of the present invention is referred to as an adjacent connection.

FIG. 6 shows an example of a driving circuit for unipolarly driving the stator windings CU1, CV1, and CW1. A switching element Q such as a field effect transistor
The stator windings CU1, CV1, and CW1 are connected via a bridge circuit including 1 to Q6 and diodes D1 to D6. That is, the stator winding CU1 is connected between the connection point between the switching element Q1 and the diode D1 and the connection point between the switching element Q2 and the diode D2, and the connection point between the switching element Q3 and the diode D3 and the switching element Q4 and the diode The stator winding CV1 is connected between the connection point with D4, and the stator winding CW1 is connected between the connection point between the switching element Q5 and the diode D5 and the connection point between the switching element Q6 and the diode D6. Then, by a control circuit not shown,
A pair of switching elements Q1 and Q2, Q3 and Q4, Q5
And Q6 are sequentially turned on and off. As a result, the stator windings CU1, CV1, and CW1 are sequentially excited and the excitation poles C
Magnetic flux passing through U1, CU2 to CW1, CW2, the rotor, and the stator yoke 1 is generated, and the rotor rotates.

In the reluctance motor according to the present embodiment, since the stator windings CU1, CV1, and CW1 are wound in adjacent connection, when the stator windings CU1, CV1, and CW1 are excited, Arrows u, v, w in FIG.
The magnetic flux indicated by. The magnetic fluxes indicated by arrows u, v, and w in FIG. 3 are generated when the U-phase stator winding CU1, the V-phase stator winding CV1, and the W-phase stator winding CW1 are excited. Magnetic flux. As can be understood from FIG. 1, in the reluctance motor of the present embodiment, a portion where the magnetic flux is not inverted occurs in a part of the stator yoke 1. In FIG. 1, the magnetic flux does not reverse in the portion between the excitation poles U1 and V2 and in the portion between the excitation poles U2 and V1 of the stator yoke 1.

When the magnetic flux of the magnetic material changes, a magnetization curve indicating a change state of the magnetic flux density B with respect to the magnetic field strength H becomes a hysteresis curve, and a hysteresis loss proportional to the area of the hysteresis curve occurs. FIG. 4 shows an example of a magnetization curve of the magnetic material when the magnetic flux does not reverse, and FIG. 5 shows an example of a magnetization curve of the magnetic material when the magnetic flux reverses. As shown in FIGS. 4 and 5, the area of the hysteresis curve when the magnetic flux does not reverse is smaller than the area of the hysteresis curve when the magnetic flux reverses, and the hysteresis loss decreases. In addition, the eddy current loss is reduced as much as the change in magnetic flux is reduced.

As described above, in the reluctance motor according to the present embodiment, a portion where the magnetic flux of the stator yoke 1 is not reversed,
That is, the hysteresis loss and the eddy current loss of the portion between the excitation poles U1 and V2 and the portion between the excitation poles U2 and V1 of the stator yoke 1 of FIG. The iron loss hardly increases even when the magnetic flux density is increased by reducing the width of the core. Therefore, the width of the motor can be reduced without increasing iron loss. For example, as shown in FIG. 1, in a conventional reluctance motor in which stator windings are symmetrically connected, the width of the motor is L.
However, in the reluctance motor of the present invention in which the stator windings are symmetrically connected, the width of the motor is set to L2 (L2 <L2).
1)

As described above, the installation space of the reluctance motor can be reduced by reducing the width of the portion where the magnetic flux of the stator yoke does not reverse, that is, the width of the motor. When a plurality of motors are arranged adjacent to each other in a row, the reluctance motor of the present invention is installed so that the portions having reduced widths face each other, so that the space use efficiency can be improved. .

On the other hand, the width of the portion other than the portion where the magnetic flux of the stator yoke does not reverse, that is, the portion where the magnetic flux reverses can be increased. This embodiment is shown in FIG. In FIG. 2, excitation poles U11, U12, V11, V12,
Stator windings CU11, CV1 for W11, W12
1. Winding direction of CW11 and stator windings CU11, CV
11, the direction of the current supplied to the CW 11 is the same as that shown in FIG. In this case, the portion where the magnetic flux of the stator yoke 10 does not reverse, that is, the portion where the magnetic flux of the stator yoke 10 reverses, while keeping the width of the portion between the exciting poles U11 and V12 and the portion between the exciting poles U12 and V11 unchanged. That is, the portion between the excitation poles V12 and W12, the excitation poles W12 and U1
The width of the portion between the two, the portion between the excitation poles V11 and W11, and the portion between the excitation poles W11 and U11 are increased. For example, as shown in FIG. 2, the outer shape of the motor is rectangular, the width of the motor in the direction sandwiching the portion where the magnetic flux is not reversed is M1, and the width of the motor in the other direction is M2 (M2> M1). In this case, by increasing the width of the portion where the magnetic flux of the stator yoke is reversed, the magnetic flux density in that portion is reduced, so that hysteresis loss and eddy current loss, that is, iron loss, are reduced. Therefore, the efficiency of the motor can be improved without increasing the width of the motor in one direction.

In the above embodiment, a three-phase reluctance motor has been described, but the present invention can be applied to a multi-phase reluctance motor other than three-phase. In addition, the method of winding the stator winding and the direction of the current supplied to the stator winding are not limited to those in the embodiments shown in FIGS. 1 and 2. I just want to be able.

As described above, by using the reluctance motor according to the first aspect, the motor width can be reduced without increasing iron loss, or without increasing the width of the motor in one direction. Motor efficiency can be improved.

【The invention's effect】 [Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of a reluctance motor of the present invention.

FIG. 2 is a diagram showing another embodiment of the present invention.

FIG. 3 is a diagram showing a conventional reluctance motor.

FIG. 4 is a magnetization curve of a portion where a magnetic flux does not reverse.

FIG. 5 is a magnetization curve of a portion where a magnetic flux is reversed.

FIG. 6 is a diagram illustrating an example of a unipolar drive circuit.

[Explanation of symbols]

 1, 10, 50 Stator yoke U1, U2-W51, W52 Excitation poles CU1-CW51 Stator winding

Claims (1)

[Claims] 1. A reluctance motor comprising: a stator having a plurality of excitation poles on which a stator yoke and a stator winding are wound; and a rotor, wherein the stator yoke is provided with the stator winding. A stator winding is wound around the excitation pole so that a portion where the direction of the magnetic flux formed by excitation does not reverse occurs, and the direction of the magnetic flux reverses the width of the stator yoke in the portion where the direction of the magnetic flux does not reverse. Reluctance motor smaller than the width of the part.