JP3104239B2 - Rotating electric machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a rotating electric machine such as a three-phase AC generator and a three-phase induction motor.

2. Description of the Related Art Conventionally, in a rotating electric machine, for example, a three-phase alternating current generator, a three-phase full-section concentrated armature winding is formed as a Y-shaped connection or a Δ-shaped connection, and these armature windings are arranged per one magnetic pole pitch. There is a three-phase full-section concentrated winding on an armature core having three slots.

[Problems to be solved by the invention] However, in the three-phase AC generator as described above,
Even if the phase currents of the armature windings x, y, and z of each phase are sinusoidal, the air gap magnetomotive force distribution on the rotor coordinates is affected by the third harmonic current included in the armature current. Fluctuates significantly. For this reason, the gap magnetomotive force distribution is greatly distorted as the rotor moves in the rotation direction, and at the same time, the gap magnetomotive force distribution fluctuates with respect to the rotor magnetic poles. Therefore, there is a problem that noise is generated due to the electromagnetic force between the air gap magnetomotive force distribution of the stator and the field magnetomotive force distribution of the rotor.

 The reason will be analyzed below.

FIG. 7 (a) shows each phase magnetomotive force Ax, Ay, obtained by multiplying the phase current of each phase armature winding by the number of turns of each phase armature winding.
The time change of Az is shown.

In the figure, times t2 and t3 are electrical angles π / 6ra from time t1.
t2 is the time when d has elapsed, and electrical angle π / 6rad from this time t2
The time after the elapse of the time is t3.

Regarding time t1, time t2 and time t3, the seventh
FIG. 7 (c) shows that the air gap magnetomotive force distribution of each phase is obtained in consideration of the arrangement of the armature windings x, y, z of each phase shown in FIG.
(E) and (g). Then, the resultant magnetomotive force distribution of each phase obtained by synthesizing the void magnetomotive force distribution of each phase is as shown in FIGS. 7 (d), (f) and (h).

That is, from FIGS. 7 (d) and 7 (h), the combined magnetomotive force distribution at time t1 and the combined magnetomotive force distribution at time t3 are the same as the amount of movement in the rotation direction of the rotor (equivalent to π / 3). Only the magnetomotive force distribution moves in the rotation direction of the rotor. However, focusing on the composite magnetomotive force distribution at time t2, the composite magnetomotive force distribution at this time is significantly different from the composite magnetomotive force distribution at time t1 and time t3.

Therefore, in the conventional three-phase AC generator, when viewed on the rotor coordinates, the air gap magnetomotive force distribution of the stator armature windings along with the movement of the rotor in the rotation direction causes the field of the magnetic poles of the rotor to change. Because the magnetic force applied to the magnetomotive force distribution fluctuates,
Electromagnetic noise is likely to occur.

Therefore, conventionally, in a three-phase AC generator, in order to reduce this electromagnetic noise, a soundproof wall for complete soundproofing is provided on the outside, or a magnetic pole of the rotor is provided so as to make the air gap uneven. Protrusions are provided to change the shape of the magnetic poles of the rotor, or the stator side is multi-groove-distributed to make the air gap magnetomotive force distribution of the armature winding sinusoidal, or magnetic pulsation of the magnetic poles or armature core In order to cancel the forces from each other, a method of giving a twist to the magnetic poles (skew) or shifting the positions of the N magnetic pole and the S magnetic pole by a half wave is used.

However, these products have a problem in that the output performance is reduced due to an increase in magnetic resistance such as an air gap, the cost is increased due to a reduction in work efficiency at the time of assembly, or a soundproof wall is provided outside the three-phase AC generator housing. However, there is a problem in that the size of the product is increased due to the provision of the above.

An object of the present invention is to provide a rotating electric machine capable of preventing electromagnetic noise without lowering output performance, increasing costs, and increasing product dimensions.

[Means for Solving the Problems] To solve the problems, the present inventors changed the magnetic action force between the field magnetomotive force distribution and the air gap magnetomotive force distribution with the movement of the rotor in the rotational direction. By not doing
It has been found that electromagnetic noise can be reduced by reducing the fluctuation of the reaction electromagnetic force applied to the rotor by the stator.

The configuration is such that a Y-shaped three-phase connection circuit in which three first windings are connected in a Y-shape, which is connected in parallel to the Y-type three-phase connection circuit, and has 1.5 to 1.5 turns with respect to the number of turns of the first winding. 2.2
Δ in which three second windings having twice the number of turns are connected in a Δ shape
A stator having a three-phase connection circuit, and a stator core in which the first winding and the second winding are housed in different slots shifted by an electrical angle of π / 6 rad; and And a rotor that rotates relatively.

Note that the first winding and the second winding may be connected to a single three-phase full-wave rectifier circuit. Also, the reason why the second winding is a winding 1.5 to 2.2 times larger than the number of windings of the first winding is that when the number of windings is other than that, a non-parallel circulating current occurs and power loss occurs. Due to inconvenience, we decided not to adopt it.

[Operation] Since the second winding having 1.5 to 2.2 times the number of turns of the first winding is housed in the plurality of slots, three first windings are provided.
The third harmonic current and three second harmonic currents respectively contained in the windings
The third harmonic current included in each winding has the same phase.

Also, since the first winding and the second winding are housed in different slots shifted by π / 6 rad in electrical angle, the flowing current flows with a phase difference of π / 6 rad in electrical angle. .

For this reason, comparing the combined magnetomotive force distribution at a certain time with the combined magnetomotive force distribution at a time after elapse of π / 6 rad from the time, the combined magnetomotive force distribution is the same in the rotation direction of the rotor by π / 6 rad. It will move in shape.

Therefore, since the magnetic acting force of the field magnetomotive force distribution and the air gap magnetomotive force distribution becomes a constant value irrespective of the position in the rotation direction of the rotor, large pulsation does not occur. Therefore, a large pulsating vibration force is not generated between the rotor and the stator.

[Effects of the Invention] The rotor and the stator are not used without providing a soundproof wall, changing the shape of the magnetic pole of the rotor, forming a multi-groove distribution winding, or providing a skew or a half-wave shift. Since no large pulsating excitation force is generated between the two, the electromagnetic noise can be reduced without lowering the output performance, increasing the cost, and increasing the size of the product.

[Embodiment] A rotary electric machine according to the present invention will be described based on an embodiment shown in Figs. 1 to 6.

1 to 5 show a first embodiment of the present invention. FIG. 1 is an electric circuit diagram of a three-phase AC generator for a vehicle, FIG. 2 is a winding specification diagram of armature windings of each phase, and FIG. 3 shows a three-phase AC generator for a vehicle. FIG. 4 is a diagram showing magnetic poles of a rotor.

The automotive three-phase AC generator 1 includes a stator 2, a rotor 3, and a three-phase full-wave rectifier circuit 4.

The stator 2 includes a Y-type three-phase connection circuit 21 and a Δ-type three-phase connection circuit.
22 and an armature core 23.

The Y-shaped three-phase connection circuit 21 includes three first windings as first windings.
The phase difference of the electromotive force is 2π / 3 between the armature acid wires x1, y1, and z1.
Are connected in a Y-shape such that The winding start of the first armature winding x1 is connected to the winding start of the first armature windings y1 and z1. Further, the number of turns of the first armature windings x1, y1, z1 is substantially the same. The first armature windings x1, y1, z1 are wound around the slots of the armature core 23 in a three-phase, full-section concentrated manner.

The Δ-type three-phase connection circuit 22 is connected in parallel to the Y-type three-phase connection circuit 21 and includes second armature windings x2 and y as three second windings.
2, z2 is set to Δ so that the phase difference between the electromotive forces becomes 2π / 3.
It is connected to the shape. The second armature windings x2, y2, z2
Is wound around the three-phase all-section concentratedly in the slot of the armature core 23.

The end of the winding of the first armature winding x1 and the end of the winding of the second armature winding x2 and the start of the winding of the second armature winding y2 are connected at one place to form the first terminal 24 between the three-phase wires. Has formed. The end of the winding of the first armature winding y1 and the end of the winding of the second armature winding y2 and the start of the winding of the second armature winding z2 are connected at one point to form the second terminal 25 between the three-phase wires. Has formed. further,
The end of the winding of the first armature winding z1 and the end of the winding of the second armature winding z2 and the beginning of the winding of the second armature winding x2 are connected in one place to form a third terminal 26 between the three-phase wires. ing.

The number of turns of the second armature windings x2, y2, and z2 is greater than the number of turns of the first armature windings x1, y1, and z1. The number of turns is large, and these are almost the same number of turns. The wire diameter of the second armature windings x2, y2, z2 is substantially equal to the wire diameter of the first armature windings x1, y1, z1. It has been. For this reason, the total cross-sectional area of the winding accommodated in each slot of the armature core 23 is substantially equal.

The armature core 23 is the stator core of the present invention, and is configured by laminating thin iron plates. This armature iron core 23
Is 12 per 2 pole pitch on the inner peripheral surface facing the rotor 3.
The slot of the location is formed. That is, the armature core
23 has twice as many slots as a conventional three-phase centralized full-section winding machine. The two magnetic pole pitch is obtained by dividing the inner peripheral surface of the armature core 23 by the number of magnetic poles, and corresponds to an armature angle of 2πrad.

In these slots, the first armature windings x1, y1, z1
And the second armature windings x2, y2, z2 are housed in the rotating direction of the rotor 3 with an electrical angle shifted by π / 6 rad (= electrical angle 30 °).

The rotor 3 includes a rotating shaft 31, a field winding 32, and a field iron core 33.
Etc.

The rotating shaft 31 is driven to rotate by the internal combustion engine, and integrally rotates with the field winding 32 and the field iron core 33.

The field winding 32 is wound around the center of the field iron core 33 in the rotational direction.

The field core 33 has a substantially trapezoidal so-called Rundel shape, and an air gap (for example, about 0.35 mm) from the armature core 23.
The armature iron core 23 is disposed at a remote position so as to face the inner peripheral surface. The field core 33 has claw-shaped magnetic poles 34 and 35 projecting from both sides toward the center. In the field iron core 33, when a current flows through the field winding 32, all of the claw-shaped magnetic poles 34 become N poles, and all of the other claw-shaped magnetic poles 35 become S poles. Also, one claw-shaped magnetic pole
Since 34 is disposed between the two other claw-shaped magnetic poles 35, twelve N-poles and S-poles are alternately disposed on the outer periphery of the field iron core 33.

The three-phase full-wave rectifier circuit 4 is composed of six diodes 41 to 46, connected to the first terminal 24 to the third terminal 26 between the three-phase wires, and connected to the Y-type three-phase connection circuit 21 and the Δ-type three-phase circuit. The AC current generated in the connection circuit 22 is rectified into a DC current. The output of the three-phase full-wave rectifier circuit 4 is supplied to an electric device or a battery via an output terminal 40.

The operation of the three-phase AC generator 1 according to the present embodiment will be described with reference to FIGS. FIG. 5 shows the first armature winding.
It is a figure which shows the air gap magnetomotive force distribution of x1, y1, z1, and 2nd armature winding x2, y2, z2.

FIG. 5 (a) shows the phase currents of the armature windings x1, y1, z1, x2, y2, z2 multiplied by the number of turns of the armature windings x1, y1, z1, x2, y2, z2. Magnetomotive force Ax1, Ay1, Az1, Ax2, Ay2, A
This shows the temporal change of z2.

Regarding time t1, time t2 and time t3 in FIG. 5 (a), the armature windings x1, y1, z1, x2, y shown in FIG. 5 (b)
When the gap magnetomotive force distribution of each phase is determined in consideration of the arrangement of z2, the results are as shown in FIGS. 5 (c), (e) and (g). Then, as shown in FIGS. 5 (d), (f) and (h), the combined magnetomotive force distribution waveforms obtained by synthesizing the air gap magnetomotive force distributions of these phases are shown at time t1, time t2 and time t3, respectively. Have the same shape, and have a stationary wave relationship with the magnetic poles 34 and 35 of the rotor 3.

That is, the reaction system of the first armature windings x1, y1, z1 and the second armature windings x2, y2, z2 is shifted by an electrical angle of π / 6 rad to move the magnetic poles 34, 35 of the rotor 3 in the rotation direction. , The resultant magnetomotive force distribution is obtained by constantly mixing and synthesizing the states shown in FIGS. 5 (d) and 5 (f). For this reason, even when the rotor 3 is moved in the rotating direction as at times t1, t2, and t3, the resultant magnetomotive force distribution is such that the field magnetomotive force distribution of the rotor 3 is equal to the air gap magnetomotive force distribution of the stator 2. The applied reaction magnetomotive force distribution waveform does not change, but only accompanies the movement of the rotor 3 in the rotation direction.

Accordingly, the magnetic force of the field magnetomotive force distribution and the air gap magnetomotive force distribution takes a constant value irrespective of the rotational position of the rotor 3 in the rotation direction of the magnetic poles 34 and 35, so that a slight slot ripple at the slot opening is obtained. No large pulsation is generated other than the magnetic pulsation based on the pulsation.

For this reason, a large pulsating vibration force is not generated between the stator 2 and the rotor 3, so that a large soundproof wall and a special process are not required, and the output performance is reduced, the cost is increased, and the product size is increased. Electromagnetic noise can be reduced without inducing the noise.

Further, since the variation of the magnetic flux on the surfaces of the magnetic poles 34 and 35 of the rotor 3 can be reduced, the magnetic resistance is remarkably reduced, so that the output efficiency of the AC generator 1 can be improved. In addition, since the heat generated by the magnetic poles 34 and 35 decreases, the temperature of the field winding decreases, so that more exciting force can be obtained, and the output efficiency of the AC generator 1 can be improved.

Further, the first armature winding x1, y1, z1 and the second armature winding
If x2, y2, and z2 are shifted in the slot by π / 6 rad and stored in the slot, their phases will differ, so two sets of three-phase full-wave rectifier circuits 4 as output load circuits are required.
Each And by connecting in parallel as a Y-shaped connection and a Δ-shaped connection so that the voltages at the first terminal 24 to the third terminal 26 between the three-phase wires have the same magnitude and the outputs have the same phase,
The generation of unbalanced circulating current is eliminated. For this reason, the output can be taken out by one set of the three-phase full-wave rectifier circuit 4, so that the AC generator 1 is low-cost and compact.

Also, regarding the wire diameter of the first armature windings x1, y1, z1 and the wire diameter of the second armature windings x2, y2, z2, Therefore, the current density is the same, and the use efficiency of the copper wire is not reduced. And winding ×
(Wire diameter) for total conductor cross-sectional area of the slot is proportional to ^the value even if the first armature winding x1, y1, z1 and second armature winding
Since it becomes uniform at x2, y2, and z2, the space utilization of the slot does not decrease.

 FIG. 6 shows a second embodiment of the present invention.

In this embodiment, diodes 47 and 48 are connected to the neutral point 27 of the Y-type three-phase connection circuit 21, and the third order included in the output of the Y-type three-phase connection circuit 21 from the neutral point 27. Harmonic current is extracted.

(Modification) In the present embodiment, a three-phase full-wave rectifier circuit is used as the output load circuit. However, a rectifier circuit using a three-phase load such as an induction motor or a heater, a transistor bridge, or a Zener diode may be used.

In the present embodiment, the present invention is used for a three-phase AC generator,
It may be used for a three-phase induction motor.

In the present embodiment, the turns ratio of the first armature winding to the second armature winding is However, the turns ratio of the first armature winding to the second armature winding may be 1: 1.5 to 2.2.

[Brief description of the drawings]

1 to 5 show a first embodiment of the present invention. First
FIG. 2 is an electric circuit diagram of a three-phase AC generator for a vehicle, FIG. 2 is a winding specification diagram of armature windings of each phase, FIG. FIG. 4 is a side view showing the magnetic poles of the rotor, and FIG. 5 is an explanatory diagram of the air gap magnetomotive force distribution of the armature windings of each phase. FIG. 6 is an electric circuit diagram of a three-phase AC generator for a vehicle employed in a second embodiment of the present invention. FIG. 7 is an explanatory diagram of a gap magnetomotive force distribution of armature windings of each phase in a conventional three-phase AC generator. In the drawing, 1 ... a three-phase AC generator (rotary electric machine) for an automobile, 2 ... a stator, 3 ... a rotor, 21 ... a Y-type three-phase wiring circuit, 22 ...
Δ-type three-phase connection circuit, 23 ... Armature core (stator core),
x1, y1, z1... first armature winding (first winding), x2, y2,
z2: First armature winding (second winding)

Claims (2)

(57) [Claims] (A) Y in which three first windings are connected in a Y-shape
A three-phase connection circuit, which is connected in parallel with the Y-type three-phase connection circuit and has three second windings each having 1.5 to 2.2 times more windings than the number of turns of the first windings, and And a Δ-type three-phase connection circuit, and the first winding and the second winding are connected by an electrical angle of π / 6ra.
A rotating electric machine comprising: a stator having a stator core accommodated in a plurality of slots shifted by d, and (b) a rotor that rotates relative to the stator. 2. The rotating electric machine according to claim 1, wherein said first winding and said second winding are connected to a single three-phase full-wave rectifier circuit.