JP3480315B2 - Rotating electric machine - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a rotary electric machine.

[0002]

2. Description of the Related Art Two synchronous motors having the same rated torque are independently provided.
It has been proposed to provide three of them and rotate them synchronously (see Japanese Patent Laid-Open No. 9-275673).

[0003]

By the way, in order to make the structure compact, it is conceivable to construct two rotors and one stator on the same shaft with a three-layer structure (see Japanese Patent Laid-Open No. 8-340663). ).

In this case, in order to rotate the two rotors separately in synchronization, a dedicated coil is prepared for each rotor in the stator, and two inverters (current controllers) for controlling the currents flowing through the dedicated coils are provided. You have to be prepared.

However, if a current is passed through each coil and each inverter, the loss due to the current (copper loss, switching loss) cannot be avoided.

Therefore, in the present invention, the coils are commonly used.
A common coil, by passing a double coupling current to the coil, and to prevent the loss due to current.

[0007]

According to a first aspect of the present invention, one stator and two rotors at least one of which has an induction coil are constructed in a three-layer structure and on the same shaft.
Generate separate rotating magnetic fields for the two rotors
A common coil is formed on the stator, and a composite current obtained by adding currents corresponding to the rotors to the common coil is passed.

In a second invention, the ratio of the number of pole pairs of the two rotors in the first invention is K: L (K is an even number, L is an odd number).
Is a combination of.

According to a third invention, in the second invention,
K is 2 and L is 1.

In a fourth aspect of the invention, in any one of the first to third aspects of the invention, the means for causing the composite current to flow through the common coil is an inverter.

According to a fifth aspect of the invention, in any one of the first to fourth aspects of the invention, the rotor is arranged at a predetermined distance outside and inside the cylindrical stator.

[0012]

According to the first aspect of the present invention, when one of the rotors is operated as a motor and the other is operated as a generator, a current corresponding to the difference between the motor driving power and the generated power is passed through a single coil. Because it is good, the efficiency is greatly improved.

When the ratio of the number of pole pairs is an even: even combination or an odd: odd combination, two rotors can be driven, but torque fluctuations occur in the rotation of the rotors. According to the invention, such torque fluctuation can be prevented.

According to the third aspect, when the rotor is provided with coils, the number of rotor coils can be minimized.

According to the fourth invention, when one of the rotors operates as a motor and the other operates as a generator,
Since the current for the difference between the motor drive power and the generated power need only be passed through the common coil, the capacitance of the power switching transistor of the inverter can be reduced, which improves switching efficiency and improves overall efficiency. To do.

According to the fifth aspect of the invention, the distance between the two rotors is the shortest from the stator. Therefore, when the same current is applied to the stator coil, one rotor is farther than the stator. Drive torque increases.

[0017]

1 is a sectional view of a rotary electric machine body 1 according to an embodiment of the invention.

In the figure, rotors 3 and 4 are arranged on the outside and inside of a cylindrical stator 2 with a predetermined gap (three-layer structure), and the inside and outside rotors 3 and 4 cover the whole. It is rotatably and coaxially provided with respect to an outer frame (not shown).

In this case, the rotor 3,
Since there are four coils, it is necessary to arrange the coils 5 in the stator 2 in order to pass a current that generates a rotating magnetic field for each rotor. For the arrangement of the twelve coils 5 shown in FIG. 1, see FIG. As a result of the consideration described above, FIG. 2 will be described first.

In FIG. 2, three sets of coils 5a (U-phase, V-phase, W-phase coils) are provided on the inner peripheral side of the stator 2 in order to flow a current (three-phase alternating current) for generating a rotating magnetic field for the inner rotor 3. In order to flow a current (three-phase alternating current) that generates a rotating magnetic field for the outer rotor 4 equally, three sets of coils 5b (A-phase, B-phase, and C-phase coils) are also provided on the outer peripheral side of the stator 2. They are evenly arranged along the circumference. However, stator 2
The total number (12) of the outer peripheral side coils 5b is twice the total number (6) of the inner peripheral side coils 5a.

On the other hand, three sets of induction coils 6 and 7 are arranged in the rotors 3 and 4 so as to face the coils 5a and 5b on the inner circumference side and the outer circumference side of the stator 2, respectively. That is, the inner rotor 3 has the same number (six) of induction coils 6 (u) as the inner peripheral side coils 5a of the stator 2.
Phase, v phase, w phase coils) equally distributed along the outer peripheral side of the rotor 3, and the outer rotor 4 has the same number (12) induction coils 7 (a phase, b) as the outer peripheral side coils 5b of the stator 2. Phase, c phase coil)
Are evenly arranged along the inner peripheral side of the rotor 4.

In order to make it easier to see the correspondence between the phases of the coils in the stator and the rotor, the stator coils 5a and 5b assigned uppercase letters to the induction coils 6 and 7 of each rotor and lowercase letters. Are allocated.

In the figure, the underline under the alphabet means that current flows in the opposite direction. For example, if a current flows toward the paper back in Figure 180 degrees two A-phase coils apart, 180-degree apart two A
In the phase coil, a current flows toward the front side of the paper in the figure.

Thus, the two stator coils 5a and 5b
When a three-phase alternating current is flown by arranging, the rotating magnetic field (inner rotating magnetic field) is generated in the induction coil 6 of the inner rotor 3 by the current flowing in the inner peripheral side coil 5a, and the current flowing in the outer peripheral side coil 5b in the outer rotor 4 is generated. A rotating magnetic field (outer rotating magnetic field) is applied to the induction coil 7. At this time, the number of pole pairs of the inner rotor 3 is 1, the number of pole pairs of the outer rotor 4 is 2, and an induction motor having a ratio of the number of pole pairs of the two rotors of 2: 1 is constructed.

Now, the three sets of coils 5a, 5b respectively arranged on the inner peripheral side and the outer peripheral side of the stator 2 are coils provided exclusively for the respective rotors 3, 4 and two dedicated coils for the stator 2 are provided. With the provision of two, it is necessary to provide two inverters for controlling the current flowing through each dedicated coil.

To deal with this, two dedicated coils 5
Consider that a and 5b are integrated (shared) as shown in FIG. Two coils close to each other in FIG. 2 (coil A and U, coil B and W , coil C and V, coil
A and U, the coil B and W, since the coil C and V) can be combined into one, when contrasting the stator coil of FIG. 2 and FIG. 1, to correspond to each rotor flowing through the stator coil 5 in FIG. 1
That current summing composite current (hereinafter referred to simply as "complex current"
Say. ) I _{1 to} I ₁₂ are

[0027]

[Equation 1] I ₁ = I _A + I _U I ₂ = I _C I ₃ = I _B + I _W I ₄ = I _A I ₅ = I _C + I _V I ₆ = I _B I ₇ = I _A + I It can be seen that _U I ₈ = I _C I ₉ = I _B + I _W I ₁₀ = I _A I ₁₁ = I _C + I _V I ₁₂ = I _B

However, in the equation (1), the underline under the current symbol indicates that the current flows in the opposite direction.

In this case, the load on the coil for passing the composite current of I ₁ , I ₃ , I ₅ , I ₇ , I ₉ , and I ₁₁ is I ₂ , I ₄ , I ₆ , I ₈ , and I ₈ ,
It is considered that the inner rotating magnetic field is formed by distributing the load to the remaining coils, because the coils become larger than the remaining coils that pass the combined currents of I ₁₀ and I ₁₂ .

For example, comparing FIG. 2 with FIG. 1, the portions of the coil 5 corresponding to the coils assigned with 1 and 2 in FIG. 1 are shown in FIG. It is U of the side coil 5a. In this case, consider the state where the phase of the U coil is slightly shifted clockwise in the figure, and if the shifted one is newly used as the _U ′ coil, half of the current I _U ′ flowing in the _U ′ coil is divided by half. Allocate to coils A and C.
The rest is the same.

By doing this, as another current setting,

[0032]

[Equation 2] I ₁ = I _A + (1/2) I _{U'I 2} = I _C + (1/2) I _{U'I 3} = I _B + (1/2) I _{W'I 4} = I _A + (1/2) I _{W'I 5} = I _C + (1/2) I _{V'I 6} = I _B + (1/2) I _{V'I 7} = I _A + (1/2) I _{U'I 8} = I _C + (1/2) I _{U'I 9} = I _B + (1/2) I _{W'I 10} = I _A + (1/2) I _{W'I 11} = I _C + _{(1/2) I V 'I 12} = I B + (1/2) I V' is obtained.

Considering further,

[0034]

Equation 3] _{I 1 = I A + Ii I} 2 = I C + Iii I 3 = I B + Iiii I 4 = I A + Iiv I 5 = I C + Iv I 6 = I B + Ivi I 7 = I _{A + Ivii I 8 = I C} + Iviii I 9 = I B + Iix I 10 = I A + Ix I 11 = I C + Ixi I 12 = may even I _B + Ixii. That is, the current I _{i of} the second term on the right side of Equation 3
_Ixii is a 12-phase alternating current as shown in FIG. 4, and the inner rotating magnetic field may be formed by the 12-phase alternating current.

FIG. 5 illustrates the current setting shown in the above equation 2 in accordance with FIG.

When the current is set as described above, two rotating magnetic fields, that is, an inner rotating magnetic field and an outer rotating magnetic field are simultaneously generated although they are common coils, but the induction coil 6 of the inner rotor 3 is rotated by the outer rotating magnetic field. The force is not applied, and the induction coil 7 of the outer rotor 4 is not applied with the rotational force by the inner rotating magnetic field. This point has been proved by theoretical analysis, as will be described later.

FIG. 3 is a block diagram for controlling the rotary electric machine 1.

The above composite currents I _{1 to} I ₁₂ are applied to the stator coil 5
In order to supply the electric current to the battery, an inverter 12 for converting a direct current from a power source 11 such as a battery into an alternating current is provided. Since the sum of all the instantaneous currents becomes 0, this inverter 12
It is the same as the 3-phase bridge type inverter with 12 phases.
It consists of four transistors and the same number of diodes as these transistors.

The ON and OFF signals given to each gate (base of the transistor) of the inverter 12 are PWM signals.

In the control circuit 15, the data of the required rotation speed for the inner rotor 3 and the outer rotor 4 (required rotation speed command value)
A PWM signal is generated based on

As described above, in one embodiment of the present invention, 1
Two rotors with two stators 2 and induction coils 6, 7.
While configuring 3 and 4 on the same axis with a three-layer structure,
Form a common coil 5 in stator 2, the common coil
5 it has to flow a double coupling current, one of the rotor as a motor, when operating the remainder as a generator, only passing a minute current difference of the motor drive power and the generated power to a single coil Since it is good, the efficiency can be greatly improved.

Further, one inverter is provided for two rotors.
When operating one of the rotors as a motor and the other as a generator, it suffices to flow a current corresponding to the difference between the motor drive power and the generated power to a common coil as described above. Therefore, the capacitance of the power switching transistor of the inverter can be reduced, which improves the switching efficiency,
Overall efficiency is improved.

Next, the ratio of the number of pole pairs of the two rotors 4 and 3 is
Theoretical analysis has revealed that in the case of the 2: 1 combination, it can function as a rotating electric machine. This theoretical analysis will be described below in terms of sections.

The simplest one in which the pole pair ratio of the two rotors is 2: 1 is the case where the outer rotor has two pole pairs and the inner rotor has one pole pair, which is the same as in FIG. ). However, when performing a theoretical analysis, it is easier to think of separating into two dedicated coils rather than sharing the stator coil as shown in FIG. .

The N (2 (2p) -2p) notation shown in FIG. 6 will be described. 2 (2p) = 4p on the left side is the number of magnetic poles of the outer rotor, and 2p on the right side is the inner rotor. Indicates the number of magnetic poles. In addition, N is a positive integer, which means that (2 (2p) -2p) is expanded and multiplied by an integer to form a ring.

Since it is an induction motor, the outer rotor
Assuming that the slip ratio of 4 is s and the slip ratio of the inner rotor 3 is σ, the outer rotor 4 has an angular velocity of (1-s) ω _{1 and} the inner rotor 3 has
It rotates at an angular velocity of (1-σ) ω ₂ . Here, when the frequency of the three-phase alternating current for driving the outer rotor is f ₁ and the frequency of the three-phase alternating current for driving the inner rotor is f ₂ , ω ₁ = 2πf ₁ , ω ₂ = 2πf ₂
Is.

<1> The influence of the rotating magnetic field for driving one rotor on the rotation of the other rotor will be examined.

<1-1> Rotating magnetic field When a three-phase alternating current for driving the inner rotor is passed through the three sets of inner stator coils U, V, W, a rotating magnetic field (inner rotating magnetic field) for the inner rotor 3 is generated. The magnetic flux density B ₂ (t, θ) at this time is

[0049]

[Formula 4] B ₂ (t, θ) = B ₂ sin (ω ₂ t-θ) where B _{2 is the} amplitude ω _{2 is the} angular velocity.

Similarly, the outer stator coils A, B, C
When a three-phase alternating current for driving the outer rotor is passed through, a rotating magnetic field (outer rotating magnetic field) is generated. Magnetic flux density B at this time
₁ (t, θ) is

[0051]

[Formula 5] B ₁ (t, θ) = B ₁ sin (2ω ₂ t−2θ) where B ₁ amplitude ω ₁ is the angular velocity.

However, in the figure, the time when the outer rotor coil a and the outer stator coil A (inner stator coil U) are in phase is considered to be zero.

<1-2> Effect of Inner Rotating Magnetic Field on Rotation of Outer Rotor When all phases of the outer rotor coil are connected in series, the electromotive voltage E induced in the outer rotor coils a, b, c
a, Eb, Ec are

[0054]

[Equation 6] Ea = d / dt × (B ₂ (t, (1-s) ω ₁ t) -B ₂ (t, (1-s) ω ₁ t + π / 2) + B ₂
(t, (1-s) ω ₁ t + π) -B ₂ (t, (1-s) ω ₁ t + 3π / 2)) Eb ＝ d / dt × (B ₂ (t, (1-s ) ω ₁ t + π / 3) -B ₂ (t, (1-s) ω ₁ t + 5π
/ 6) + B ₂ (t, (1-s) ω ₁ t + 4π / 3) -B ₂ (t, (1-s) ω ₁ t + 11π / 6)) Ec ＝ d / dt × (- B ₂ (t, (1-s) ω ₁ t + π / 6) + B ₂ (t, (1-s) ω ₁ t + 2
π / 3) -B ₂ (t, (1-s) ω ₁ t + 7π / 6) + B ₂ (t, (1-s) ω ₁ t + 5π / 3)).

Calculation is performed by substituting the equation (4) into the equation (6).

[0056]

[Equation 7] Ea = d / dt × B ₂ (sin (ω ₂ t- (1-s) ω ₁ t) -sin (ω ₂ t- (1-s) ω ₁
t-π / 2) + sin (ω ₂ t- (1-s) ω ₁ t-π) -sin (ω ₂ t- (1-s) ω ₁ t-
3π / 2)) Eb ＝ d / dt × B ₂ (sin (ω ₂ t- (1-s) ω ₁ t-π / 3) -sin (ω ₂ t- (1-
s) ω ₁ t-5π / 6) + sin (ω ₂ t- (1-s) ω ₁ t-4π / 3) -sin (ω ₂ t-
(1-s) ω ₁ t-11π / 6)) Ec ＝ d / dt × B ₂ (-sin (ω ₂ t- (1-s) ω ₁ t-π / 6) + sin (ω ₂ t- (1
-s) ω ₁ t-2π / 3) -sin (ω ₂ t- (1-s) ω ₁ t-7π / 6) + sin (ω ₂ t-
(1-s) ω ₁ t-5π / 3))

[0057]

[Equation 8] Ea = d / dt × B ₂ (sin (ω ₂ t- (1-s) ω ₁ t) + sin (ω ₂ t- (1-s) ω ₁
t-π) -sin (ω ₂ t- (1-s) ω ₁ t-π / 2) -sin (ω ₂ t- (1-s) ω ₁ t-
3π / 2)) Eb ＝ d / dt × B ₂ (sin (ω ₂ t- (1-s) ω ₁ t-π / 3) + sin (ω ₂ t- (1-
s) ω ₁ t-4π / 3) -sin (ω ₂ t- (1-s) ω ₁ t-5π / 6) -sin (ω ₂ t-
(1-s) ω ₁ t-11π / 6)) Ec ＝ d / dt × B ₂ (-sin (ω ₂ t- (1-s) ω ₁ t-π / 6) -sin (ω ₂ t- (1
-s) ω ₁ t-7π / 6) + sin (ω ₂ t- (1-s) ω ₁ t-2π / 3) + sin (ω ₂ t-
(1-s) ω ₁ t-5π / 3))

[0058]

[Equation 9] Ea = d / dt × B ₂ (sin (ω ₂ t- (1-s) ω ₁ t) -sin (ω ₂ t- (1-s) ω ₁ t) -sin (ω ₂ t -(1-s) ω ₁ t-π / 2) + sin (ω ₂ t- (1-s) ω ₁ t-π / 2)) = 0 Eb ＝ d / dt × B ₂ (sin (ω ₂ t- (1-s) ω ₁ t-π / 3) -sin (ω ₂ t- (1-s) ω ₁ t-π / 3) -sin (ω ₂ t- (1-s) ω ₁ t -5π / 6) + sin (ω ₂ t- (1-s) ω ₁ t-5π / 6)) = 0 Ec ＝ d / dt × B ₂ (-sin (ω ₂ t- (1-s) ω ₁ t-π / 6) + sin (ω ₂ t- (1-s) ω ₁ t-π / 6) + sin (ω ₂ t- (1-s) ω ₁ t-2π / 3) -sin ( ω ₂ t- (1-s) ω ₁ t-2π / 3)) = 0 That is, the current for creating the inner rotating magnetic field does not act on the outer rotor coil, and the electromotive force does not occur, so the outer rotor coil No electric current flows through it, and therefore no driving force is generated.

<1-3> Effect of Outer Rotating Magnetic Field on Rotation of Inner Rotor The electromotive voltages Eu, Ev, Ew induced in the inner rotor coils u, v, w by the outer rotating magnetic field are the same as those of the inner rotor coils. If all the players are connected in series,

[0060]

[Equation 10] Eu = d / dt × (B ₁ (t, (1-σ) ω ₂ t + α) -B ₁ (t, (1-σ) ω ₂ t + π +
α)) Ev ＝ d / dt × (B ₁ (t, (1-σ) ω ₂ t + 2π / 3 + α) -B ₁ (t, (1-σ) ω
₂ t + 5π / 3 + α)) Ew ＝ d / dt × (-B ₁ (t, (1-σ) ω) ₂ t + π / 3 + α) + B ₁ (t, (1-σ) ω
₂ t + 4π / 3 + α)) where α: Outer rotor coil a and outer stator coil A
It is the phase shift of the inner rotor coil u at the time when the phase with (inner stator coil U) matches.

The calculation is performed by substituting the equation 5 into the equation 10.

[0062]

[Equation 11] Eu = d / dt × B ₁ (sin (2ω ₁ t-2 (1-σ) ω ₂ t-2α) -sin (2ω ₁ t-
2 ((1-σ) ω ₂ t + π) -2α)) Ev ＝ d / dt × B ₁ (sin (2ω ₁ t-2 ((1-σ) ω ₂ t + 2π / 3) -2α) -si
n (2ω ₁ t-2 ((1-σ) ω ₂ t + 5π / 3) -2α)) Ew ＝ d / dt × B ₁ (sin (2ω ₁ t-2 ((1-σ) ω ₂ t + 4π / 3) -2α) -si
n (2ω ₁ t-2 ((1-σ) ω ₂ t + π / 3) -2α))

[0063]

[Equation 12] Eu = d / dt × B ₁ (sin (2ω ₁ t-2 (1-σ) ω ₂ t-2α) -sin (2ω ₁ t-2 (1-σ) ω ₂ t-2π- 2α)) = 0 Ev ＝ d / dt × B ₁ (sin (2ω ₁ t-2 (1-σ) ω ₂ t-4π / 3) -2α) -sin (2ω ₁ t-2 (1-σ) ω ₂ t-10π / 3) -2α)) = 0 Ew ＝ d / dt × B ₁ (sin (2ω ₁ t-2 (1-σ) ω ₂ t-8π / 3-2α) -sin (2ω ₁ t-2 (1-σ) ω ₂ t-2π / 3-2α)) = 0 That is, the current for creating the outer rotating magnetic field does not act on the inner rotor coil, and the electromotive voltage does not occur. No current flows in the rotor coil and therefore no driving force is generated.

<1-4> Summary The current for driving the inner rotor does not affect the rotation of the outer rotor, and the current for driving the outer rotor does not affect the rotation of the inner rotor. As a result, as will be described later, only the inner rotor can be controlled by the current for driving the inner rotor, and only the outer rotor can be controlled by the current for driving the outer rotor.

<2> The driving force is calculated from the relationship between the outer rotor coil and the current for driving the outer rotor.

<2-1> Electromotive voltage induced in the outer rotor coil The electromotive voltages Ea, Eb, Ec induced in the outer rotor coils a, b, c by the outer rotating magnetic field are generated by the phases of the outer rotor coils. If they are all connected in series,

[0067]

[Equation 13] Ea = d / dt × (B ₁ (t, (1-s) ω ₁ t) -B ₁ (t, (1-s) ω ₁ t + π / 2) + B ₁
(t, (1-s) ω ₁ t + π) -B ₁ (t, (1-s) ω ₁ t + 3π / 2)) Eb ＝ d / dt × (B ₁ (t, (1-s ) ω ₁ t + π / 3) -B ₁ (t, (1-s) ω ₁ t + 5π
/ 6) + B ₁ (t, (1-s) ω ₁ t + 4π / 3) -B ₁ (t, (1-s) ω ₁ t + 11π / 6)) Ec ＝ d / dt × (- B ₁ (t, (1-s) ω ₁ t + π / 6) + B ₁ (t, (1-s) ω ₁ t + 2
π / 3) -B ₁ (t, (1-s) ω ₁ t + 7π / 6) + B ₁ (t, (1-s) ω ₁ t + 5π / 3)).

The calculation is performed by substituting the equation 5 into the equation 13.

[0069]

[Equation 14] Ea = d / dt × B ₁ (sin (2ω ₁ t-2 (1-s) ω ₁ t) -sin (2ω ₁ t-2 ((1-
s) ω ₁ t + π / 2)) + sin (2ω ₁ t-2 ((1-s) ω ₁ t + π))-sin (2ω ₁ t
-2 ((1-s) ω ₁ t + 3π / 2))) Eb ＝ d / dt × B ₁ (sin (2ω ₁ t-2 ((1-s) ω ₁ t + π / 3))- sin (2ω ₁
t-2 ((1-s) ω ₁ t + 5π / 6)) + sin (2ω ₁ t-2 ((1-s) ω ₁ t + 4π /
3))-sin (ω ₁₂ t-2 ((1-s) ω ₁ t + 11π / 6))) Ec ＝ d / dt × B ₁ (-sin (2ω ₁ t-2 ((1-s) ω ₁ t + π / 6)) + sin (2ω
₁ t-2 ((1-s) ω ₁ t + 2π / 3))-sin (2ω ₁ t-2 ((1-s) ω ₁ t + 7π /
6)) + sin (2ω ₁ t-2 ((1-s) ω ₁ t + 5π / 3)))

[0070]

[Equation 15] Ea = d / dt × B ₁ (sin (2sω ₁ t) -sin (2 (sω ₁ t + π / 2)) + sin (2
(sω ₁ t + π))-sin (2 (sω ₁ t + 3π / 2))) Eb ＝ d / dt × B ₁ (sin (2 (sω ₁ t + π / 3))-sin (2 ( sω ₁ t + 5π /
6)) + sin (2 (sω ₁ t + 4π / 3))-sin (2 (sω ₁ t + 11π / 6))) Ec ＝ d / dt × B ₁ (-sin (2 (sω ₁ t + π / 6)) + sin (2 (sω ₁ t + 2π /
3))-sin (2 (sω ₁ t + 7π / 6)) + sin (2 (sω ₁ t + 5π / 3)))

[0071]

## EQU16 ## Ea = d / dt × B ₁ (sin (2sω ₁ t) -sin (2sω ₁ t + π) + sin (2sω
₁ t + 2π) -sin (2sω ₁ t + 3π)) Eb ＝ d / dt × B ₁ (sin (2sω ₁ t + 2π / 3) -sin (2sω ₁ t + 5π / 3) + s
in (2sω ₁ t + 8π / 3) -sin (2sω ₁ t + 11π / 3)) Ec ＝ d / dt × B ₁ (-sin (2sω ₁ t + π / 3) + sin (2sω ₁ t + 4π / 3) -s
in (2sω ₁ t + 7π / 3) + sin (2sω ₁ t + 10π / 3))

[0072]

[Equation 17] Ea ＝ d / dt × 4B ₁ (sin (2sω ₁ t)) Eb ＝ d / dt × 4B ₁ (sin (2sω ₁ t + 2π / 3)) Ec ＝ d / dt × 4B ₁ (sin (2sω ₁ t + 4π / 3))

[0073]

(Equation 18) Ea = 8sω ₁ B ₁ (cos (2sω ₁ t)) Eb = 8sω ₁ B ₁ (cos (2sω ₁ t + 2π / 3)) Ec = 8sω ₁ B ₁ (cos (2sω ₁ t + 4π / 3)) <2-2> Current flowing in outer rotor coil Currents Ia, Ib, Ic flowing in outer rotor coil have a predetermined phase difference η when the outer rotor coil is loaded with impedance Z ₁ .

[0074]

Ia = 8I ₁ sω ₁ cos (2sω ₁ t + η) Ib ＝ 8I ₁ sω ₁ cos (2sω ₁ t + 2π / 3 + η) Ic ＝ 8I ₁ sω ₁ cos (2sω ₁ t + 4π / 3 + η) However, I ₁ is the amplitude.

However, the impedance Z ₁ has an appropriate magnitude (I ₁ = B ₁ / │Z) by replacing B ₁ with I _1.
1 |) is selected.

<2-3> Magnetic Field Received by Outer Rotor Coil The magnetic field received by the outer rotor coil is given by θ in the above equation 5.
Since (1-s) ω ₁ t, (1-s) ω ₁ t-2π / 3, and (1-s) ω ₁ t-4π / 3 should be substituted,

[0077]

[Equation 20] Ba (t) = B ₁ sin (2ω ₁ t-2 (1-s) ω ₁ t) = B ₁ sin (2sω ₁ t) Bb (t) = B ₁ sin (2ω ₁ t-2 ((1-s) ω ₁ t-2π / 3)) ＝ B ₁ sin (2sω
₁ t-4π / 3) Bc (t) ＝ B ₁ sin (2ω ₁ t-2 ((1-s) ω ₁ t-4π / 3)) ＝ B ₁ sin (2sω
₁ t-8π / 3).

The forces fa, fb, and fc that the current flowing through the outer rotor coil receives from the magnetic field according to the equations (19) and (20) are as follows.

[0079]

[Formula 21] fa = Ia × Ba = 8I ₁ sω ₁ cos (2sω ₁ t + η) × B ₁ sin (2sω ₁ t) fb = Ib × Bb = 8I ₁ sω ₁ cos (2sω ₁ t + 2π / 3 + η) × B ₁ sin (2s
ω ₁ t-4π / 3) fc = Ic × Bc = 8I ₁ sω ₁ cos (2s ω ₁ t + 4π / 3 + η) × B ₁ sin (2s
ω ₁ t-8π / 3)

[0080]

[Equation 22] fa = 8I ₁ B ₁ sω ₁ cos (2sω ₁ t + η) sin (2sω ₁ t) fb ＝ 8I ₁ B ₁ sω ₁ cos (2sω ₁ t + 2π / 3 + η) sin (2sω ₁ t-4π / 3) fc ＝ 8I ₁ B ₁ sω ₁ cos (2sω ₁ t + 4π / 3 + η) sin (2sω ₁ t-8π / 3) where cos (a) sin (b) = 1 / Using the formula of 2 (sin (a + b) -sin (ab))

[0081]

[Mathematical formula-see original document] fa = 4I ₁ B ₁ sω ₁ (sin (2sω ₁ t + η + 2sω ₁ t) -sin (2sω ₁ t + η-
2sω ₁ t)) fb ＝ 4I ₁ B ₁ sω ₁ (sin (2sω ₁ t + 2π / 3 + η + 2sω ₁ t-4π / 3) -si
n (2sω ₁ t + 2π / 3 + η-2sω ₁ t + 4π / 3)) fc = 4I ₁ B ₁ sω ₁ (sin (2sω ₁ t + 4π / 3 + η + 2sω ₁ t-8π / 3) -si
n (2sω ₁ t + 4π / 3 + η-2sω ₁ t + 8π / 3))

[0082]

[Equation 24] fa = 4I ₁ B ₁ sω ₁ (sin (4sω ₁ t + η) -sin (η)) fb ＝ 4I ₁ B ₁ sω ₁ (sin (4sω ₁ t-2π / 3 + η) -sin (2π + η)) fc = 4I ₁ B ₁ sω ₁ (sin (4sω ₁ t-4π / 3 + η) -sin (4π + η)) <2-4> Driving force Driving force F is The sum of fa, fb and fc should be multiplied by the number of coils.

[0083]

[Equation 25] <2-5> Summary According to Equation 25, it is shown that the driving force acting on the outer rotor can be controlled by the three-phase alternating current flowing into the outer stator coils A, B, and C.

<3> The driving force is calculated from the relationship between the inner rotor coil and the inner rotor driving current. The analysis here is almost the same as the above <2> as described below.

<3-1> Electromotive voltage induced in the inner rotor coil The electromotive voltages Eu, Ev, Ew induced in the inner rotor coils u, v, w by the inner rotating magnetic field are the phases of the inner rotor coils. If they are all connected in series,

[0086]

[Equation 26] Eu = d / dt × (B ₂ (t, (1-σ) ω ₂ t + α) -B ₂ (t, (1-σ) ω ₂ t + π +
α)) Ev ＝ d / dt × (B ₂ (t, (1-σ) ω ₂ t + 2π / 3 + α) -B ₂ (t, (1-σ) ω
₂ t + 5π / 3 + α)) Ew ＝ d / dt × (-B ₂ (t, (1-σ) ω) ₂ t + π / 3 + α) + B ₂ (t, (1-σ) ω
₂ t + 4π / 3 + α)), the equation (4) is substituted into this equation (26) for calculation.

[0087]

[Equation 27] Eu = d / dt × B ₂ (sin (ω ₂ t- (1-σ) ω ₂ t-α) -sin (ω ₂ t- (1-
σ) ω ₂ t-π-α)) Ev ＝ d / dt × B ₂ (sin (ω ₂ t- (1-σ) ω ₂ t-2π / 3-α) -sin (ω ₂
t- (1-σ) ω ₂ t-5π / 3-α)) Ew ＝ d / dt × B ₂ (sin (ω ₂ t- (1-σ) ω ₂ t-π / 3-α) -sin (ω ₂ t
-(1-σ) ω ₂ t-4π / 3-α))

[0088]

(Equation 28) Eu = d / dt × 2B ₂ sin (σω ₂ t-α) Ev = d / dt × 2B ₂ sin (σω ₂ t + 2π / 3-α) Ew = d / dt × 2B ₂ sin ( σω ₂ t + 4π / 3-α)

[0089]

(Equation 29) Eu = 2B ₂ σω ₂ cos (σω ₂ t-α) Ev = 2B ₂ σω ₂ cos (σω ₂ t-2π / 3-α) Ew = 2B ₂ σω ₂ cos (σω ₂ t-4π / 3-α) <3-2> Current flowing in the inner rotor coil The currents Iu, Iv, Iw flowing in the inner rotor coil have a predetermined phase difference γ when the load of impedance Z ₂ is applied to the inner rotor coil.

[0090]

Iu = 2I ₂ σω ₂ cos (σω ₂ t-α + γ) Iv = 2I ₂ σω ₂ cos (σω ₂ t-2π / 3-α + γ) Iw = 2I ₂ σω ₂ cos (σω ₂ t-4π / 3-α + γ) where I ₂ is the amplitude.

However, the impedance Z ₂ has an appropriate magnitude (I ₂ = B ₂ / │Z) by replacing B ₂ with I _2.
2 ｜) is selected.

<3-3> Magnetic field received by inner rotor coil The magnetic field received by the inner rotor coil is (1-σ) ω
Substituting ₂ t-α, (1-σ) ω ₂ t-α-2π / 3, (1-σ) ω ₂ t-α-4π / 3,

[0093]

(31) Bu (t) = B ₂ sin (ω ₂ t- (1-σ) ω ₂ t-α) = B ₂ sin (σω ₂ t-
α) Bv (t) ＝ B ₂ sin (ω ₂ t- (1-σ) ω ₂ t-α-2π / 3) ＝ B ₂ sin (σ
ω ₂ t-α-2π / 3) Bw (t) ＝ B ₂ sin (ω ₂ t- (1-σ) ω ₂ t-α-4π / 3) ＝ B ₂ sin (σ
We get ω ₂ t-α-4π / 3).

According to the equations (30) and (31), the forces fu, fv, fw that the current flowing through the inner rotor coil receives from the magnetic field are as follows.

[0095]

[Equation 32] fu = Iu × Bu = 2I ₂ σω ₂ cos (σω ₂ t-α + η) × B ₂ sin (σ
ω ₂ t-α) fv = Iv × Bv = 2I ₂ σω ₂ cos (σω ₂ t-α + η-2π / 3) × B ₂ s
in (σω ₂ t-α-2π / 3) fw ＝ Iw × Bw ＝ 2I ₂ σω ₂ cos (σω ₂ t-α + η-4π / 3) × B ₂ s
in (σω ₂ t-α-4π / 3)

[0096]

[Mathematical formula-see original document] fu = 2I ₂ B ₂ σω ₂ cos (σω ₂ t-α + η) × sin (σω ₂ t-α) fv = 2I ₂ B ₂ σω ₂ cos (σω ₂ t-α + η-2π / 3) × sin (σω ₂ t
-α-2π / 3) fw ＝ 2I ₂ B ₂ σω ₂ cos (σω ₂ t-α + η-4π / 3) × sin (σω ₂ t
-α-4π / 3) where we use the formula cos (a) sin (b) ＝ 1/2 (sin (a + b) -sin (ab))

[0097]

[Equation 34] fu ＝ 2I ₂ B ₂ σω ₂ (1/2 (sin (σω ₂ t-α + η + σω ₂ t-α) -sin
(σω ₂ t-α + η-σω ₂ t + α))) fv ＝ 2I ₂ B ₂ σω ₂ (1/2 (sin (σω ₂ t-α + η-2π / 3 + σω ₂ t-
α-2π / 3) -sin (σω ₂ t-α + η-2π / 3-σω ₂ t + α + 2π /
3))) fw ＝ 2I ₂ B ₂ σω ₂ (1/2 (sin (σω ₂ t-α + η-4π / 3 + σω ₂ t-
α-4π / 3) -sin (σω ₂ t-α + η-4π / 3-σω ₂ t + α + 4π /
3)))

[0098]

F = I ₂ B ₂ σω ₂ (sin (2σω ₂ t + η-2α) -sin (γ)) fv ＝ I ₂ B ₂ σω ₂ (sin (2σω ₂ t + η-2α-4π / 3) -sin (γ)) fw ＝ I ₂ B ₂ σω ₂ (sin (2σω ₂ t + η-2α-8π / 3) -sin (γ)) <3-4> Driving force Driving force F is The sum of the forces fu, fv, and fw can be multiplied by the number of coils.

[0099]

[Equation 36] <3-5> Summary According to the formula 36, the driving force acting on the inner rotor can be controlled by the three-phase alternating current flowing into the inner stator coils U, V, W.

<4> Summary As described above, the drive currents applied to the A, B, and C-phase stator coils act only on the outer rotor coils a, b, and c, and the impedance Z ₂ becomes equal to that of the normal induction motor. Depending on A-a, B
A phase difference η is generated between −b and C−c, which causes a driving force to be generated in the outer rotor. Similarly, the drive currents flowing in the U, V, and W phase stator coils are
It acts only on v and w, which is also U depending on the impedance Z _2.
A phase difference γ is generated between −u, V−v, and W−w, which causes a driving force to be generated in the inner rotor.

In this way, it was proved that the rotor functions as a rotating electric machine when the pole pair number ratio of the two rotors is 2: 1.

This completes the theoretical analysis.

In the embodiment, the combination of the pole pair number ratio is 2: 1 (that is, the even number: odd number combination), but the combination of the pole pair number ratio is not limited to this. : It has been found that even an odd number of combinations can work as a rotating electric machine.

However, in the case of a combination of even: even and odd: odd, both rotors can be driven, but the current for driving the outer rotor affects the inner rotor coil (the current for driving the outer rotor is (This affects the rotor coil), which causes torque fluctuations in the rotation of the rotor.

On the other hand, when the pole pair number ratio is an even: odd combination, as described above in <1>, the current for driving the outer rotor is supplied to the inner rotor coil and the current for driving the outer rotor. Since the electric current of 1 does not affect the inner rotor coil, the torque fluctuation does not occur.

Further, when the pole-pair number ratio is an even-odd combination, particularly when the even-number is 2 and the odd-number is 1, the number of rotor coils can be minimized. For example, the pole logarithm
Two coils are required for one, and three times as many coils are required to pass a three-phase alternating current, so the total number of inner rotor coils is 2 × 3 = 6. Similarly, the total number of outer rotor coils is doubled to 12 coils. On the other hand, when the pole logarithmic ratio is other than 2: 1,
The least common multiple of the total number of two rotor coils will exceed 12.

In the embodiment, the case where the induction coils are arranged in the two rotors has been described. However, the present invention is not limited to this, and at least one rotor may include the induction coils. For example, either one of the rotors may be composed of a permanent magnet or an electromagnet.

In addition, the arrangement of the stator and the two rotors may basically be any arrangement. For example, two rotors can be arranged inside the stator, or two rotors can be arranged outside the stator.

The motor drive current circuit is not limited to the case of using the PWM signal, but may be the case of using the PAM signal or other signals.

In the embodiment, the structure of the rotary electric machine is a radial gap type (there is a gap between the rotor and the stator in the radial direction).
However, the present invention can also be applied to an axial gap type (there is a gap between the rotor and the stator in the axial direction).

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a rotating electric machine body according to an embodiment.

FIG. 2 is a schematic cross-sectional view of a rotating electric machine body in which dedicated coils are arranged on an inner peripheral side and an outer peripheral side of a stator 2.

FIG. 3 is a control system diagram.

FIG. 4 is a waveform diagram showing a distribution of 12-phase alternating current.

FIG. 5 is a waveform chart showing an AC distribution.

FIG. 6 is a model diagram to be referred to when considering an N (2 (2p) -2p) basic form.

[Explanation of symbols]

2 stator 3 Inner rotor 4 outer rotor 5 coils

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H02K 16/02 H02K 17/02

Claims (5)

(57) [Claims] 1. A stator and two rotors, at least one of which is provided with an induction coil, are constructed in a three-layer structure and on the same shaft, and separate rotors are provided for the two rotors.
A common coil for generating a rotating magnetic field is formed in the stator, and a current corresponding to each rotor is formed in the common coil.
A rotating electric machine characterized in that a combined current obtained by adding the above is applied . 2. The ratio of the number of pole pairs of the two rotors is K: L (K
Is an even number and L is an odd number), and the rotating electric machine according to claim 1, wherein: 3. The rotating electric machine according to claim 2, wherein the K is 2 and the L is 1. 4. The means for causing the composite current to flow through the common coil is an inverter.
The rotating electric machine according to any one of the above. 5. The rotor is arranged on the outer side and the inner side of a cylindrical stator at a predetermined interval.
The rotating electrical machine according to any one of 1 to 4.