JPH01138985A - Variable speed induction motor - Google Patents

Abstract

PURPOSE:To enable a speed controlling range to be widely set, by short- circuiting between two sets of the coaxially arranged rotors of an induction motor, with a resistance member, and by providing a one-side stator with a voltage phase shifter. CONSTITUTION:On a rotor shaft 4, rotor cores 2, 5, 3 are fitted, and respective conductors 6 arranged respectively on the rotor cores 2, 5, 3 are connected penetrated through the rotor cores 2, 5, 3 to form an integral rotor 7. The conductors 6 are respectively connected at the rotor core 5 via a resistance member 9. In the meantime, stators 24, 25 with windings 22, 23 arranged on the external side, confronted with the rotor cores 2, 3 are arranged in parallel with a machine frame 14. The one side of the 24, 25 is provided with a voltage phase shifter. As a result, torque can be certainly controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a variable speed induction motor with good torque characteristics and efficiency and easy speed control.

(Prior art and its problems) One method of controlling the speed of an induction motor is to change the power supply frequency. Although this method allows for continuous and wide-range speed control, it requires expensive frequency conversion equipment, and generally harmonics and radio waves are generated in the process of converting AC into DC and then back into AC using the frequency conversion equipment. These occur by computer.

The metal type may cause problems such as malfunction of electrical control equipment or overheating of capacitors. Among these, countermeasures against harmonic interference can be taken by installing filters, but installing filters is costly. Additionally, they have drawbacks such as generally insufficient performance at low speeds.

Furthermore, the method of controlling the speed by changing the number of poles of the electric motor has the disadvantage that, although the speed can be changed stepwise by changing the number of poles, it is not possible to perform arbitrary speed control over a wide range.

Furthermore, although the method of controlling the speed by changing the voltage of the power supply allows speed control over a wide range, it has the disadvantage that efficiency is poor, especially in the low speed range.

In wire-wound motors, the method of controlling the speed by changing the secondary resistance and changing the slip is relatively easy and allows for speed control over a wide range. Inserting a resistor requires maintenance and inspection due to brush wear, and squirrel cage induction motors have the problem that speed control cannot be performed by changing the secondary resistance.

To address the above problems, for example,
The technology is disclosed in Publication No. 29005 (2), and this is a squirrel cage conductor that is commonly installed across two sets of rotor cores and short-circuited at both ends via short-circuit rings. and a high-resistance element that shorts the squirrel-cage conductors at the center of the cage-shaped conductors between the two sets of rotor cores. At startup, the phase between the stator windings is set to 1.
This is a twin core squirrel-cage type motor that supplies power in phase with each other during operation after startup, but by shifting the phase between the stator windings by 180 degrees during startup, the starting torque is increased and the starting characteristics are improved. It is characterized in that it can be operated with normal torque characteristics by matching the phases of the stator windings during operation.

Therefore, even if the effect of improving startability is recognized, this electric motor is not a variable speed electric motor, so it cannot be used as a power source for a load that requires variable speed. There was no disclosure of any technology for preventing heat dissipation or a reduction in the strength of the rotor, and the system was not suitable as a power source for a load that frequently starts and stops.

In addition, in the above-mentioned Japanese Patent Application Laid-Open No. 54-29005, the power supply circuits of the stator windings are momentarily connected in series for the purpose of mitigating the shock caused by sudden fluctuations in torque when transitioning from startup to operation. One example is to provide an intermediate step, but in this case, the phase shift of the rotating magnetic field is limited to the same points of 0° and 180°, and is not intended for speed change. Moreover, by switching to series, the voltage applied to the stator is halved, so the torque is reduced to 1/4.
It is clear from the fact that the subject matter disclosed in this publication is not aimed at shifting, that this together with the reduction in speed makes it impossible to control the shift at all.

Furthermore, JP-A-49-86807 proposes an asynchronous electric motor having a stator with polyphase windings and a squirrel-cage rotor, including conductive bars, short-circuit end rings, and ferromagnetic laminations. 2), the stator comprises first and second winding sections arranged coaxially adjacent each other and different parts of the rotor;
an asynchronous electric motor which can be supplied with an alternating current of the same frequency and is provided with means for varying the electromotive force induced in the rotor windings by means of a second winding section; Alternatively, by electrical means 2), although it is possible to change the rotational speed by creating a phase difference between the two stator sections, there is a resistance that shorts the conductive bars between each other at the center of the conductive bars. Since it does not have a body, it does not generate heat, but the torque is small except when the phase angle between the two stator sections is the same, and the operation stops immediately when a load is applied, making it completely unusable. De 2
), which left unresolved the serious problem that it cannot be operated as a power source that repeatedly starts and stops when a load is connected.

(Object of the Invention) The present invention is intended to improve the above-mentioned drawbacks of the prior art, and is capable of widening the speed control range, setting the speed control to any desired speed, and starting with any torque. The purpose of this invention is to provide a variable speed induction motor that can

The variable speed induction motor of the present invention is used by being connected to a single-phase or three-phase power supply, and the rotor has a normal squirrel cage type, a double squirrel cage type, or a deep groove cage type.

It can be applied to any type of special squirrel-cage rotor core, etc. 2) The conductor used in the explanation of the present invention refers to a conductor installed in a squirrel-cage rotor core, and a wound rotor core. This is a general term for each of the windings wound on the winding.

[Means for solving problems]

In order to achieve the above-mentioned technical problem, the present invention includes a rotor core made of a magnetic material equipped with a plurality of conductors, and a plurality of fixed conductors mounted on an outer peripheral portion facing the rotor. The children are arranged in parallel on a machine frame, and insulation treatment is applied between the rotor core of the rotor portion that does not face the plurality of stators and the plurality of conductors, and between the plurality of stators. The plurality of conductors are short-circuited via a resistive material in a portion of the rotor that does not face the stator, and the conductor is induced in a conductor portion of the rotor that faces at least one stator among the plurality of stators. A means for solving this problem is to attach a voltage phase shifter to create a phase difference between the voltage and the voltage induced in the conductor portion of the rotor facing the other stator.

(Function) According to the present invention, when a phase shift is caused in the magnetic flux of the rotating magnetic field generated between the respective stators by arbitrary means 2), the magnetic flux is induced in the rotor conductor according to the phase shift of the magnetic flux. The voltage changes, and the rotational speed of the rotor can be changed arbitrarily by increasing or decreasing the voltage induced in the rotor conductors.

By the way, a rotor is formed by installing a plurality of conductors in a rotor core made of a magnetic material, and a plurality of stators are arranged in parallel on the machine frame on the outer periphery facing the rotor. Insulating treatment is performed between each of the plurality of conductors and the rotor core of the rotor portion not facing the stator, and the plurality of conductors are insulated in the rotor portion not facing the plurality of stators. 2) By short-circuiting through the resistive material, the rotor of the variable speed induction motor can be manufactured easily, and the reduction in strength of the rotor due to the influence of heat generated by the resistive material during operation is improved. It also improves dissipation. In addition, in the rotor portion that does not face the stators, insulation treatment is applied between the multiple conductors and the rotor core, so that the current does not flow between the conductors through the rotor core in a short circuit, and the resistor Since the current flows between the conductors through the material in a short-circuit manner, the torque can be reliably controlled by the phase difference.

〔Example〕

Embodiments of the invention are primarily described with respect to variable speed induction machines with squirrel cage rotors, but are not limited thereto.

Embodiments of the present invention will be described based on FIGS. 1 to 12.

One embodiment of the present invention will be explained with reference to FIGS. 1 to 3. Reference numeral 1 denotes a variable speed induction motor 2) according to the present invention, and the variable speed induction motor 1 has the following configuration. A rotor core 2, 5.3 made of magnetic material is mounted on the rotor shaft 4,
A plurality of conductors 6 installed in the rotor core 2.5.3...
are connected to each other through the rotor core 2.5.3 to form an integral rotor 7, and both ends of the plurality of conductors 6 connected in series are connected by short-circuit rings 8.8. Short circuit.

In addition, a plurality of ventilation shells 12 . A plurality of ventilation holes 13 are perforated orthogonally through the outer circumference of the rotor 7 at the rotor core 5. Conductors installed in the rotor 7...6 are nichrome wires in the rotor core 5 section between the rotor cores 2 and 3.

Carbon-containing steel 9 Resistance material 9 made of electrically conductive ceramic, etc.
・It is connected via. Bearing discs 15 and 16 provided on both sides of the cylindrical machine frame 14 are connected to connecting rods 17 with nuts 1.
8. Assemble integrally by tightening... Cooling impellers 19.20 are mounted on both sides of the rotor 7, and bearings 21 are fitted at both ends of the rotor shaft 4 into bearing discs 15.16.
21, and the rotor 7 is rotatable.

A first stator 24 and a second stator 25, each having a winding 22.23 on the outer side facing the rotor cores 2 and 3, of a rotor core 2.3.5 made of a magnetic material are mounted on the machine frame 14. A sliding bearing 26 is installed between the machine frame 14 and the first stator 24, and the sliding bearing 26 is fixed by a stop ring 28 fitted to the machine frame 14. The child 25 is fixed to the machine frame 14 by a fixing ring 27. A gear 29 is fitted onto the outer peripheral surface of one side of the first stator 24 . A driving gear 31 is pivotally attached to a small motor 30 fixed to the outer periphery of the machine frame 14, and the driving gear 31 is engaged with a gear 29 fitted to the first stator 24. With this configuration, 2) the first stator 24 is rotated concentrically with the rotor 7 by the operation of the small motor 30. Thus, the rotation of the first stator 24 and the second stator 25 constitute a voltage phase shifting device.

Next, the configuration of the cooling device for the induction motor 1 will be explained. An air blowing port 34 and an air exhaust port 35 are bored in the outer periphery of the machine frame 14, and a blower 36 having a motor 37 is fixed to the air exhaust port 35, so that the air in the space 38 is circulated outside the machine frame 14. Also, cooling impellers 19 and 2 that rotate integrally with the rotor shaft 4
0. Air is taken in from the ventilation hole 32 and the side part 10°11,
It is provided to circulate air through the ventilation trunk 12 and the ventilation port 13. 33 is a vent for air circulation, which is located in the first part of the machine frame 14.
It is perforated in a portion facing the stator 24 and the second stator 25.

The annular heat shield 39 is a heat shield 39A provided in a space between the winding 22 wound around the first stator 24 and the resistive material 9 connected to the conductor 6 between the rotor core 2.3. The material is made of a material with low heat absorption and low thermal conductivity, such as polished stainless steel. A metal such as a plate, a ceramic material, or the like is used.

In this embodiment, it is fixed to the stator core, but
It may be fixed to the machine frame 14 or the rotor 7 in some cases. Machine frame/
14 has the advantage of not receiving direct heat conduction from the rotor 7, but must be removed during assembly because of the protrusion of the resistive material 9 of the rotor 7.

Next, the connection of the windings 22 and 23 wound around each of the first stator 24 and the second stator 25 will be explained based on FIG. 2.3. What is shown in FIG. The windings 22 and 23 provided on each of the second stators 24 and 25 are star-connected and connected in series to a power source. That is, the terminals A, B, and C of the winding 22 of the first stator 24 are connected to the commercial three-phase power supply A, B, and C, and the terminals a, b of the winding 22 are connected to the commercial three-phase power supply A, B, and C.
, c are connected to the terminals A, B, and C of the winding 23 of the second stator 25, and the terminals a, b, and c of the winding 23 are short-circuited and connected.

Moreover, the one shown in FIG. Second stator 24.25
The windings 22 and 23 are connected in series and delta-connected to a commercial three-phase power supply, but a detailed explanation thereof will be omitted. Note that the parallel connection is similar to that of an ordinary induction motor. 6A in Figure 3.

6B shows the wiring of the wire-wound rotor wound around the rotor core 2.3.

The operation of the above configuration will be explained below based on FIGS. 1 to 7.

When the windings 22 of the first stator 24 are energized from a commercial three-phase power source, a rotating magnetic field is generated in the stator 24, 25, a voltage is induced in the rotor 7, and a current is generated in the conductors 6 of the rotor 7. The flow causes the rotor 7 to rotate.

When the amount of rotation of the first stator 24 with respect to the second stator 25 is set to zero, each stator 24.25
, there is no phase shift in the voltage induced in the conductor 6 of the rotor 7, and the details will be explained later in the resistive material 9...
Since no current flows through the motor, it has the same torque characteristics as a general induction motor.

Next, a case will be described in which the small motor 30 is operated to rotate the first stator 24 by a phase angle of θ. The magnetic flux φ1 of the rotating magnetic field created by the first stator 24 and the second stator 25.
The phase of φ2 is shifted by θ with respect to the conductor 6 of the rotor 72), so the first stator 24 and the second stator 2
Voltage white 1 induced in the conductor 6 of the rotor 7 by 5
．． The phase of white will be shifted by θ. Now, with the voltage ω induced in the conductors 6 of the rotor 7 by the second stator 25 as a reference, this voltage is assumed to be m-3E. Here, S is the slip 2) and E is the induced voltage when the slip is 1. At this time, the voltage d1 induced in the conductor 6 by the first stator 24 is 6+=SEεJll.

Referring to FIG. 4, the short-circuit ring 8 of the conductor 6 of the rotor 7
The respective resistances from to the resistive material 9 are R1 and R2, the inductances are Ll and L2, and the angular frequency of the power source is ω.
If the resistance of the resistive material that short-circuits each of the conductors 6 is r, then the electrical equivalent circuit of the rotor 7 is as shown in Fig. 42), with the symbols 1+, Iz, 1: + indicates the current flowing through each branch.

Next, when converting the circuit shown in Fig. 4 into an equivalent circuit as seen from both stator 24 and 25 sides, it becomes as shown in Fig. 52), R+=
When R2, LI=L2 and θ-0°, 13=II-1
2=O, and no current flows through the resistive material 9. This means that when θ=0°, the torque T is equal to the value without the resistance material 9. Therefore, when θ=0°, it has the same torque characteristics as a conventional induction motor.

Next, when RI=R2, LI=L2 and θ=180°, 11=-12, l3=Il-I2-2112)
In a conventional induction motor, if the resistance of the rotor conductors 6 is set to R++R2=R, the same result is obtained as if R were increased to R+2r.

2) Due to the rotation of the rotor 7, the cooling impeller 19°20 opens the machine frame 1 from the ventilation holes 32 bored in the bearing discs 15 and 16.
The outside air is sucked into the cooling impeller 19.20.
．． The second stator 24° 25 and the windings 22, 23 are ventilated and cooled, and the rotor core 2, 3, the conductors 6, . ...,
The resistive material 9, etc. are cooled to stably perform their respective functions. Also, 1st. The rotation of the second stator 24, 25 is carried out by rotating the small motor 30 in forward and reverse directions using a switch, but this is not limited to the small motor 30, and other forward and reverse motors may also be used, as well as gas, liquid cylinders, etc. Any drive device such as a servo mechanism can be used. The rotation of the stator is controlled to an arbitrary rotation speed in relation to the operation of the drive device that rotates the stator.

Next, the effect of connecting the windings 22 and 23 wound around the first stator 24 and the second stator 25 in series will be explained.

Since the windings 22 and 23 are connected in series, the windings 22 and 23 are connected in series.
A current flows between the windings 22 and 23 when input from a commercial 3-phase power source, but if there is a difference in the resistance of each of the windings 22 and 23 or a difference in the capacitance of both stators 24 and 25, If any, each winding 22.2
The magnitude of the current flowing through the rotor 7 is equal, and therefore the magnitude of the current induced and flowing from each of the first stator 24 and the second stator 25 to the conductor 6 of the rotor 7 is equal. Both stator 2
4.25 to the conductors 6 of the rotor 7 to be equal in size, and the vector difference caused by the phase difference in voltage between both stators 24.25. Due to the synergistic effect of the current flowing through each of the plurality of conductors 6 through the resistive material 9, which creates a forcing force2), the slip and As with torque characteristics, it is possible to improve efficiency and produce large torque in each speed range, and even when a load is connected, it is easy to start in each speed range, and it improves the starting characteristics of the load. It can be used to adapt to a smooth start, or to start with high output, and can be used to suit a power source that is frequently started and stopped.

As mentioned above, the speed of the rotor 7 is changed by controlling the phase shift by rotating the first stator 24, and by rotating the first stator 24.
The rotational speed of the rotor 7 can be changed arbitrarily only by increasing or decreasing the current flowing through the rotor 7.

Note that the first stator 24 has windings 22 and 23 connected in series.
and the second stator 25 to the conductor 6 of the rotor 7, respectively.
・For the magnitude of the current flowing through the multiple conductors 6...
The ratio of the short-circuited current flowing through the resistive material 9 between them is determined by the value of Pθ (P = number of pole pairs, θ = phase angle), regardless of the resistance value and slip of the resistive material 9. (The above ratio is the maximum for Pθ-π and becomes zero at Pθ=O.) If Pθ is constant, the same slip as when the secondary insertion resistance of a general wound induction motor is constant. Regarding the torque characteristics 2), when Pθ becomes small, the conductor 6 of the rotor 7...
Since the ratio of current flowing through the motor is small2), reducing Pθ has the same effect as reducing the secondary insertion resistance of a general wound induction motor. When the rated current flows through both stators 24 and 25, the phase difference θ
Depending on the selection of the slip value and the design of the resistance value of the resistance material 92), the rated current and rated torque characteristics of the maximum speed can be applied almost simultaneously in each speed change range even if the rated current and torque characteristics of the maximum speed are changed arbitrarily. .

In addition, the windings 22.2 of the first stator 24 and the second stator 25
If each of 3 is connected in parallel to a commercial 3-phase power supply,
The voltages input to the windings 22.23 of the first stator 24 and the second stator 25 are equal, and the voltages induced from each of the stators 24.25 to the conductors 6 of the rotor 7 are equal. The voltage phases differ by Pθ 2), multiple conductors 6...
The current flowing between the resistance material 9... is (1/2
)×(differential voltage induced in the rotor conductor from each of the first and second stators)÷(resistance value r of the resistive material 9). However, the conductor 6 of the rotor 7
In addition to the current flowing through the resistive material 9..., the first...
A current approximately proportional to (sum voltage induced in the rotor conductor of the second stator)/(impedance of the rotor conductor) flows in a superimposed manner.

(The above sum voltage is maximum when Pθ = π is zero and Pθ = 02), ・The impedance of the rotor conductor is composed of the resistance of the conductor and the secondary leakage reactance, so it varies depending on the slippage.) Therefore, the rotation The ratio of the current flowing between the plurality of conductors 6 through the resistive material 9 to the magnitude of the current flowing through the conductor 6 of the child 7 is determined by the slip and resistance value even if Pθ is constant. 2) The slip and torque characteristics when Pθ is constant are the characteristics when the secondary insertion resistance of a general wound induction motor is constant,
The characteristics shown in FIG. 7 are a mixture of the characteristics obtained when the primary voltage of a general induction motor is controlled. This characteristic is the first.
Compared to the characteristics when the windings 22 and 23 of the second stator 24° 25 are connected in series, the speed control range becomes narrower in the case of certain load characteristics, but the reduced torque characteristics In the case of loads, it can be used over a wide range, almost the same as in the case of series connection.

As mentioned above, the torque characteristics can be improved by passing a current through the resistance material 9 provided between the conductors 6.
The current flowing through the resistive material 9 increases or decreases depending on the phase difference, and most of the electrical energy is converted into heat, so the resistive material 9. Heat is generated locally in the 6 parts of the conductor. In order to prevent this heat generation from affecting the resistance material 9° conductor 6 and deteriorating its durability, the rotor core 2.5.3 is integrated to increase its strength and promote heat dissipation.

Next, as shown in FIG. 8, the first stator 24 and the second stator 2
The connection of the windings formed to have a plurality of types of pole numbers in each of No. 5 will be explained.

The first stator 24 is provided with double windings 41A and 41B, and the second stator 25 is also provided with a double winding 42A.

42B, and each of the windings 41A and 42A is provided with a 4-pole terminal and an 8-pole terminal LJ2. V2. W2 and U4. V4
．． W4 is provided, and terminals U+, Vt, W+c [FIJ3.
V3 and W3 are equipped with tigers. The windings 4, 1A of the first stator 24 and the winding 42A of the second stator 25 are connected in series, and similarly the windings 41B and 42B of both stators 24.25 are connected in series. It is. More specifically, the terminal U4 of the winding 41A of the first stator 24. V4. W4
is connected to the terminal U3. of the winding 41B via the pole number changeover switch S2. V3. W3 are respectively connected to the commercial three-phase power supply via the pole number changeover switch S3, and are connected to the terminals U2... of the winding 41A. V2
゜W2 is connected to the winding 41B via the pole number changeover switch S4.
Terminals U+, V+, and W+ are each connected to a commercial three-phase power source via a pole number changeover switch $1.

Terminal X2 of the winding 41A of the first stator 24. Y2 and Z2 are connected to the terminal U2. of the winding 42A of the second stator 25. V2. The winding 4 of the first stator 24 is connected to W2 via a switch $8.
1B terminal X+.

Y+ and Z+ are connected to the terminal U+ of the winding 42B of the second stator 25,
V+, W+, and the terminals X2. of the winding 42A of the second stator 25. Y2. Z2 is connected via the pole number changeover switch Sss,
Also, terminal U4 of winding 42A. V4. W4 is connected to LJ2. of winding 41A via pole number conversion switch SI. W2. X2.V2 of winding 41A via S6. Z2° is connected to Y2. Terminals X+, Y+, and Z+ of winding $142B of the second stator 25 are connected to a commercial three-phase power supply via a pole number changeover switch S16, and winding 42B (7) terminal U3. V: +, W3 are connected to U + , W 1°vl of the winding 41B via the pole number changeover switch S9, and are connected to 81.21. of the winding 41A via S5. It is connected to Y+. Furthermore, terminal U2 of winding 42Δ. V2. W2
X2. of winding 42A via Sr1. Y2. It is connected to Z2 and shorted at 814. Similarly, winding 42
Terminals U+, V+, W+ of B are also connected to terminals X+, Y1 . It is connected to Z+ and can be shorted at 813. The operation of the above configuration will be explained with reference to FIG. 1.

1st. The number of poles of the windings 41A and 42A wound around the second stator 24 and 25 is 4 poles and 8 poles, respectively.
Since the number of poles of B and 42B is 6 and 12, the synchronous speed at each number of poles is like a robe.

Relationship between the number of poles and synchronous speed (rpm) From the above relationship between the number of poles and synchronous speed, if the rotational speed required for the rotor shaft 4 in the 60H2 area is 1l100.
rp, the number of poles changeover switch 83.85.
89. When SL+, 813 is turned on and the other switches are opened, the 1st. Second stator 24.2
5 winding 41B.

42B is energized, and the voltage induced from both stators 24, 25 to the rotor conductors 6 causes the rotor shaft 4 to roar at 1200 rpm, which is the synchronous speed of the 6 poles.
In order to reduce the rotational speed by 10100 rpm from 0 rpm to 0 rpm, the small motor 30 is operated to
is rotated, and the phase shift generated in each conductor portion of the rotor 7 is controlled by both stators 24 and 25 to adjust the rotation speed to a desired rotation speed. Next, when the rotational speed required for the rotor shaft 4 is 400 rpm, the pole number changeover switch S+ is turned on.

37. Turn on SI6 and open the other switches, and change the 12-pole synchronous speed from 600 rpm to 40 orp.
A small motor 30 rotates both stators 24 and 25 to adjust the speed in a small range of 200 rpm.

Next, the rotation speed required for the rotor shaft 4 is 80 orpm.
, the number of poles changeover switch 84°Sa, SF
When i is turned on and the other switches are opened, the rotor shaft 4 becomes 8-pole synchronous speed, so the small motor 3
0 to control the phase shift by rotating both stators 24 and 25 to adjust the speed to 800 rpm.

When 1600 rpm is required for the rotor shaft 4, the pole number changeover switches S2, 86 . Sl.

When Srz and S+4 are turned on and the other switches are opened, the rotor shaft 4 becomes 4-pole synchronous speed, so the small motor 3
Rotate both stators 24 and 25 by 0 to 1eoorpm
The phase shift is controlled so that , .

The rotational speed in the embodiment described above is controlled by operating the pole number changeover switches 81 to S+e as appropriate2). The amount of rotation can be made small, speed control can be performed steplessly, and the speed 11i1J This can be understood from the relationship between slip and torque for four poles and eight poles shown in the figure. Of course, due to the synergistic effect with the effect of connecting the windings wound around both stators 24 and 25 in series as explained in the previous embodiment, efficiency can be improved in a wide range of control ranges and large torque can be produced. It has remarkable effects when used in power sources that require frequent and wide-ranging start-up, stop, and shift control.

In addition to the embodiments described above, both stators 24.2
The number of poles of the windings to be wound in 5 can be selected according to the speed control range2).For example, if four stators are provided and multiple types of windings are attached to each. The rotation speed can be controlled over a wider range by applying current to the number of poles required for the rotation speed and controlling the phase shift using a pole number changeover switch and a voltage phase shifter. In addition, since stepwise speed control can be performed by changing the number of poles, the amount of rotation of both stators 24.25, which serves as a voltage phase shifter, is required to be small for speed change adjustment in a small range. Only one of them may be rotated (or, accurate phase control may be performed by setting a difference in the amount of rotation of both of them and rotating them in the same direction).

Next, according to FIG. 10, as another embodiment of the voltage phase shifting device,
A configuration in which a phase changeover switch and a pole number changeover switch are connected to a winding wound around a stator to form a voltage phase shifter will be described.

1st. Winding 4 applied to each of the second stators 24, 25
3.44 each has a terminal that converts the number of poles to two.2), 1st. Winding 43.44 of second stator 24.25
are connected to terminals LJ+, V+, Wt and U2.
V2. W2 is provided, and the terminal U2 . of the winding 43 is provided. V2. The terminal W2 is connected to the terminal U via the pole number changeover switch S17.
+, V+, and W+ are each connected to a commercial three-phase power supply via a pole number changeover switch S1s, and are connected to terminals U+ and X of the winding 43.
+, the terminals V+ and Yl, and the terminals Wl and 71 are connected through the pole number changeover switch S+a, and the winding 43
A connecting stroke path 45 connecting the winding 44 and the winding 44 in series and the commercial 3
A plurality of phase changeover switches serving as a voltage phase shifter 47 are interposed in a connecting path 46 to the phase power source.

That is, the terminals X+, Y+, and Z+ of the winding 43 connected to the pole number changeover switch S17 are connected to the terminals LID, V+, and
The terminal X+ of the winding 43 is connected to the terminal X+ of the winding 43 in the same manner.

Yl and Zl are connected to the terminal Y of the winding 44 via the switch 82B.
+, Z+, X+, winding 44 via switch S3 [l
are connected to the terminals W+, LID, V+ of the winding 44 via the switch 87B. It is connected to Z1. The terminals U1 and ×1 of the winding 44, the terminals V1 and Yl, and the terminal W1
and 71 are connected via a phase changeover switch S19,
The circuit of each terminal can be short-circuited via phase switches 821 and 825.

Furthermore, phase changeover switches S22°SZI and S24.827 are provided in the series connection path 45 between the windings 43 and 44 and the connection path 46 between each terminal of the winding 44 and the commercial three-phase power source.
．． S29.832.833 are interposed between each other.
), the details of the connection between each switch and each terminal of the winding 44 will be explained in conjunction with the explanation of the function to be described later.In this embodiment, the first . Without rotating the second stator 24,25, the first stator. Both of the second stators 24 and 25 are fixed to the machine frame 14, pole number changeover switches 817 to S are provided, and a phase changeover switch 82 is provided.
The only difference from that shown in FIG. 1 is that a voltage phase shifter 47 is formed by components 1 to 333 (2), and the other configurations are the same, so a detailed explanation thereof will be omitted.

The operation of the above embodiment will be explained below with reference to FIG.

First, when operating at maximum speed, switch the number of poles selector ST7. S+8.8I9 and phase selection switch S
When 22 and -8 s are turned on and the other switches are opened, the windings 43 and 44 are connected in series in the same phase and have the same torque characteristics as a general induction motor. Next, the number of poles changeover switch S17. With S+e and Sm still on, phase changeover switch S21. S
When 27 is turned on and the other switches are opened, winding 43
The phase of the voltage input to the winding 44 is shifted by 60 degrees with respect to the phase of the voltage input to the winding 4.
The rotational speed of the rotor 7 decreases in accordance with the phase shift of 60° compared to when the phases of 3.44 and 3.44 are in the same phase.

Next, the pole number changeover switch S+7. With S+a and S+a still on, the phase selector switch 823.8
25, the phase of the voltage input to the winding 44 is shifted by 120 degrees from the phase of the voltage input to the winding 43 (2), and the speed is even lower than when the phase shift is 60 degrees. It becomes rotation.

In order to rotate at a lower speed than this state, pole number changeover switch St1. If S+a and Sm are left turned on, phase changeover switch Sz+ and 82B are turned on, and all other switches are opened, the phase of the voltage input to the winding 43 and the voltage input to the winding 44 will be out of phase by 180". , with the same number of poles, it is possible to rotate at the lowest speed, but in this case, the torque will decrease, so switch to a different number of poles that is higher than the number of poles applied to the windings 43 and 44. It is efficient to control the rotational speed 2), and its operation will be explained below.

First, turn on the pole number changeover switch 820 on the winding 43 side,
Further, when the phase changeover switch S24.831 is turned on and the others are opened, the winding 43 and the winding 44 are energized via the phase changeover switch S31 interposed in the connecting stroke path 45, and the current is passed through the phase changeover switch S24.831. 24 to the commercial three-phase power supply, and the voltages input to each of the windings 43 and 44 have the same phase 2), resulting in the maximum rotational speed for this number of poles. Next, when the phase selection switch 828 and 832 is turned on and the other switches are opened while leaving the pole number selection switch SM on, the phases of the voltages input to each of the windings 43 and 44 will be shifted by 60 degrees. 2) The rotational speed is lower than when the respective phases are in phase.

Next, while keeping the pole number changeover switch 820 closed, the phase changeover switches 329 and 831 are turned on and the other switches are opened, so that the phases of the windings 43 and 44 are set to 120.
The rotation speed is lower than that when the phase shift is 60 degrees. Furthermore, when setting the rotation speed to the minimum, leave the pole number changeover switch 820 on, turn on the phase changeover switches S and 53Il, and open the other switches, so that the phase of the voltage input to each of the windings 43 and 44 changes. 18
The rotation speed corresponds to a 0° shift and a phase shift.

As described above, by appropriately operating the phase changeover switches S 21 to 833 and the pole number changeover switches Sy and 820, which constitute the voltage phase shifter 47, 2) efficient rotation speed control can be performed.

In this way, the voltage phase shifter 47 can be used to control the phase of the voltage input between a plurality of stators each having a single or multiple number of pole windings. The feature of this embodiment in which the voltage phase shifter 47 is a phase changeover switch is that although the rotational speed cannot be controlled steplessly, the rotational speed can be quickly changed in multiple stages by switching the number of poles and phase. At the point. Note that in this embodiment, the first and second stators 24
．． By rotating both or one of the voltage phase shifters 25 and auxiliary phase control, the speed can be changed steplessly, and the control can be performed quickly. Even if it is attached, the rotational speed can be changed arbitrarily.

Next, another embodiment of the voltage phase shifter will be described based on FIG.

The terminals A, B, and C of the winding 22 of the first stator 24 are connected to the commercial three-phase power supply A, B, and C, and the terminals a, b, and c of the winding 22 are connected to the winding 22 of the second stator 25. A single-phase transformer 49 and a connection switch 4 are connected in series to terminals A, B, and C of the
8 and a voltage phase shifter 50. There is no intervention.

To explain the structure in detail, the terminal a of the winding 22.

Primary side 49 of a single-phase transformer on b and c. Wiring selection switch 8
34 and 835 are connected as shown in the figure, a connection changeover switch 836°S37 is connected to the secondary side of the single-phase transformer 49, and terminals A, B, and C of the winding 23 are connected to connection changeover switches 834 to S37.
It is connected to each of 37.

The operation of this embodiment will be explained below. Commercial 3
When the windings 22 are energized from the phase power supplies A, B, and C, and only the electromagnetic switch 834 of the wiring connection switch 48 is turned on and the others are opened, the phases of the voltages of the windings 22 and 23 are in the same phase and the maximum rotational speed is reached. becomes. Next, the wiring selection switch 8
When only 36 is turned on and the other switches are opened, winding 2
3 through the transformer 49 is the phase of the voltage input to the winding 22.
The voltage is 60° ahead of the phase of the voltage input to 2.
), the rotation speed is slower than when the voltages are in phase.

When only the connection changeover switch 835 is turned on, the phase of the voltage input to the winding 23 is 120° ahead of the phase of the voltage input to the winding 22 (2), and the phase shift is 60°. The rotation speed will be even slower than before. Next, when only the wire connection switch 837 is turned on, the winding 22
The phase of the voltage input to the winding 23 is 180° ahead of the phase of the voltage input to the winding 23 (2), resulting in the lowest rotational speed. In addition, by switching each connection, the first stator 2
4. The phase shift of the voltage generated between the second stator 25 changes in stages. Second stator 24.2
By rotating either or both of 5, the rotational speed can be controlled to an arbitrary speed. In this case, a large rotational speed change is performed by the connection changeover switch, and is auxiliary controlled by the rotation of the stator, so that rapid speed change control can be performed with the amount of rotation of the stator within a small range.

Next, another embodiment of the voltage phase shifter will be described with reference to FIG.

The terminals A, B, and C of the winding 22 of the first stator 24 are connected to the commercial three-phase power supply A, 8. A three-phase induced voltage adjustment device is connected to C and has a stator fixed thereon, with a rotor rotatable inside the stator, and a primary winding 52 on the stator and a secondary winding 53 on the rotor. The regulator 51 is a voltage phase shifter, and the terminals A, B, and C of the primary winding 52 of the three-phase induction voltage regulator 51 are connected to the terminals a, b, and c of the winding 22 of the first stator 24, and - Terminals a and b of the next winding
, c are shorted. The terminals a, b, and c of the secondary winding 53 are short-circuited, and the terminals A, B, and C are connected to the terminals A, B, and C of the winding 23 of the second stator 25. Terminal a of line 23.

Short-circuit b and c.

In this embodiment, by rotating the rotor of the three-phase induction voltage regulator 51 equipped with the secondary winding 53 by an arbitrary amount,
, 1st. The phase of the voltage input to the windings 22 and 23 of the second stators 24 and 25 can be changed, and the rotation speed can be controlled according to the rotation speed required of the rotor shaft 4.

In addition, in FIG. 1, the resistance material 9 covers all the rotor conductors 6.
Even if it is not connected to ..., the appropriate effect can be obtained.

The voltage phase shifting device is not limited to the above embodiment, and any device that causes a phase shift between both stators can be selected and implemented. Further, even if the conductors installed in the rotor core have low resistance, if a resistive material is provided between each conductor to short-circuit the conductors, the improvement in torque characteristics and efficiency of the present invention as described above can be ensured. If the winding to be wound around the stator is not one that has undergone several types of pole number conversion, winding is applied to each of the multiple rotor cores and connected in series, and during the process If a resistive material is interposed in the winding, either star connection or delta connection can be selected and used for the winding.

In addition, by using any of the voltage phase devices mentioned above and combining the star connection and delta connection of a plurality of stators, two
), it goes without saying that a wider range of speed control is possible.

Furthermore, the variable speed induction motor of the present invention can also be used as an induction generator (2), and if a turbine or the like is directly connected to the rotor shaft 4 to generate electricity, an expensive governor can be omitted. . In addition, when an internal combustion engine is connected as a prime mover, it can correspond to the engine speed that achieves the minimum fuel consumption of the internal combustion engine, and even when the power generated from feng shui as an energy source is weak and unstable, the rotation speed that can produce its maximum output is possible. In hydroelectric power generation, power can be generated efficiently according to the flow velocity, and complicated and expensive variable pitch devices or phase adjusters can be omitted.

[Effects of the Invention] According to the variable speed electric motor of the present invention, a rotor is formed by installing a plurality of conductors on a rotor core made of a magnetic material, and a plurality of conductors are fixed to the outer circumference facing the rotor. the plurality of stators are arranged in parallel on a machine frame, insulation treatment is applied between each of the plurality of conductors and the rotor core of the rotor portion that does not face the plurality of stators, and the plurality of stators and the plurality of conductors are insulated. 2) Due to the configuration in which the plurality of conductors are short-circuited via the resistive material in the rotor portions that do not face each other, the effect of heat generation of the resistive material during operation, especially during operation that causes a phase difference in which current flows through the resistive material. This improves the strength loss of the rotor caused by heat dissipation and improves heat dissipation. In addition, in the rotor core parts that do not face multiple stators, the rotor core and conductors are insulated, so the current does not flow between the rotor cores in a short circuit, and torque can be controlled reliably. At the same time, the rotor can be manufactured easily and robustly.

[Brief explanation of the drawing]

Figures 1 to 12 are illustrations of embodiments of the present invention.
The figure is a side sectional view of a variable speed induction motor, Figures 2 and 3 are wiring diagrams of the windings wound around both stators, Figure 4 is an electrical equivalent circuit diagram of the rotor, and Figure 5 is a fixed Figure 6 is a diagram showing the relationship between speed and torque when stator windings are connected in series, Figure 7 is an electrical equivalent circuit diagram seen from the child side, and Figure 7 is a diagram showing the relationship between stator windings connected in parallel. A diagram showing the relationship between speed and torque in case of
Fig. 8 is a wiring diagram when multiple types of windings are applied to the stator and the number of poles is changed by a switch, Fig. 9 is a graph showing the relationship between slip and torque characteristics for 4 and 8 poles, and Fig. 10
The figure is a connection diagram of the phase changeover switch and the pole number changeover switch that form the voltage phase shifter to the stator winding, and Figure 11 is an example diagram in which the voltage phase shifter is configured with a single-phase transformer and a phase changeover switch. , FIG. 12 is a diagram showing an embodiment in which the voltage phase shifter is constructed with an inductive voltage regulator. , 1... variable speed induction motor, 2, 3... rotor core, 4... rotor shaft, 5... rotor core, 6...
Conductor, 6A, 6B... Rotor winding, 7... Rotor,
8... Short circuit ring, 9... Resistance material, 10.11... Side part, 12... Ventilation barrel, 13... Ventilation port, 14...
Machine frame, 15. 16... Bearing board, 17... Connecting rod, 1
8... Nut, 19° 20... Cooling impeller, 21.
...Bearing, 22.23...Winding, 24...First stator, 25...Second stator, 26...Sliding bearing, 2
7... Fixed ring, 28... Stop ring, 29...
・Gear, 30... Small motor, 31... Drive gear, 32... Ventilation port, 33... Ventilation port, 34...
・Air outlet, 35...Exhaust port, 36...Exhaust fan, 37
...Motor, 38...Space, 39°39A, 3
9B... Heat shield, 41A, 41B... Double winding,
42A, 42B...Double winding, 43°44...Winding, 45.46...Connection stroke path, 47...Voltage phase shifter, 48...Connection changeover switch, 49... - Single-phase transformer, 50... Voltage phase shifter, 51... Induction voltage regulator, 52...-Secondary winding, 53... Secondary winding.

Claims (7)

[Claims] (1) A rotor is formed by installing a plurality of conductors in a rotor core made of a magnetic material, and a plurality of stators are arranged in parallel on the machine frame on the outer periphery facing the rotor, and the Insulating treatment is performed between the rotor core of the rotor portion that does not face the plurality of stators and the plurality of conductors, and in the rotor portion that does not face the stator between the plurality of stators. The plurality of conductors are short-circuited via a resistive material, and a voltage induced in a conductor portion of the rotor facing at least one stator among the plurality of stators is induced in a conductor portion facing the other stator. A variable speed induction motor, characterized in that the variable speed induction motor is further equipped with a voltage phase shift device that creates a phase difference between the voltage induced in the conductor portion of the rotor. (2) The voltage phase shifting device induces a voltage in a conductor portion of the rotor facing at least one stator among the plurality of stators, and a voltage induced in a conductor portion of the rotor facing the other stator. The phase generated between the voltage induced in the conductor part is 0°
At least one of the plurality of stators is rotatably formed concentrically with the rotor so that a desired phase shift can be set and maintained within a range of 180° from A variable speed induction motor according to claim (1). (3) The voltage phase shifting device is a phase switching switch connected to a winding wound around at least one stator among the plurality of stators. Variable speed induction motor. (4) The variable speed induction motor according to claim (1), wherein the voltage phase shift device is formed by a single-phase transformer and a connection changeover switch. (5) The variable speed induction motor according to claim (1), wherein the voltage phase shift device is an induction voltage regulator. (6) According to claim (1), each of the plurality of stators is provided with a winding forming a plurality of types of pole numbers, and a pole number changeover switch is connected to the terminal of the winding. Variable speed induction motor. (7) A switch according to claim (1) is provided, which is provided with a switch that can freely switch the connection of the windings wound around each of the plurality of stators to either delta connection or star connection. Variable speed induction motor.