JPS6120202B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic levitation propulsion device that propels and drives a moving object while magnetically supporting it.

Conventionally, as this type of magnetic levitation propulsion device, the first
There is a configuration as shown in the figure. Figure 1 shows this device applied to a magnetically levitated train. In the figure, 1 is a track with a T-shaped cross section, and this track 1 has a pair of rails 2 along the lower surface of both side edges.
A secondary iron core 4 including a secondary conductor made of, for example, aluminum plates and plates of a linear induction conductor, which will be described later, is laid along the center of the upper surface.

On the other hand, a vehicle body 5 running along the track 1 is supported by a pedestal 6 that holds the track 1. This pedestal 6 is provided with an electromagnet 7 that generates an attractive force (levitation force) to the rails 2, 2. This electromagnet 7 is denoted by numerals 7 ₁ and 7 in FIG.
As shown in ₂ , ₇₃ , and _74, it is divided into four parts and placed at the four corners of the pedestal 6. In this case, these electromagnets 7
₁ , 7 ₂ , 7 ₃ , 7 ₄ have displacement meters 8 ₁ , 8 ₂ , 8 ₃ , 8 that detect the gap length between the rail 2 and the electromagnet 7
₄ , the gap length control circuits 9 ₁ , 9 ₂ , 9 ₃ , 9 ₄ and the variable power supplies 10 ₁ , 10 ₂ , 10 ₃ , 10 ₄ are connected, respectively, and the respective electromagnets 7 ₁ , 7 ₂ , 7 ₃ , 7 are connected.
The levitation force of ₄ is controlled.

Further, a linear induction conductor 11 that provides a propulsion force to the vehicle 5 is provided on the pedestal 6 so as to face the iron core 4 including the secondary conductor. This electric motor 11 is arranged at the center of the pedestal 6 as shown in FIG. Further, a power source 12 is connected to this electric motor 11 to control the propulsion force.

By the way, it is known that when a propulsive force is generated by a linear induction machine in this way, the electric motor 11 generates an attractive force between it and the secondary iron core 4.

However, in the conventional configuration described above, this attraction force acts in the opposite direction to the levitation force of the electromagnet 7, that is, it acts equivalently to increasing the vehicle weight. Therefore, the electromagnet 7 requires an extra levitation force, which not only increases power consumption but also unnecessarily increases the capacity of the control system for the electromagnet 7.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a magnetic levitation propulsion device that can be made lightweight as a whole and can significantly reduce power consumption.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 3 shows the application of this invention to a magnetically levitated train. In the figure, reference numeral 21 denotes a track, and a pair of ferromagnetic material rails 22, 22 are laid down and parallel to the track 21. On the other hand, a moving object such as a vehicle body 23 traveling along this track 21
is supported by a pedestal 24 having a T-shaped cross section. This frame 24 is provided with an electromagnet 25 that generates an attractive force (levitation force) and an armature 26 (not shown) of a linear induction machine that generates a propulsive force and an attractive force in correspondence with the rails 22, 22. ing.

In this case, as shown in FIG. 4, the electromagnets 25 are divided into four parts at 25 ₁ , 25 ₂ , 25 ₃ , and 25 ₄ and placed at the four corners of the frame 24, and the armatures 26 are arranged at 26 ₁ and 26 _2. The armature 26 1 is divided into two parts, and one of the armatures 26 ₁ is connected to the electromagnets 25 ₁ and 25 _3.
between the other armature 26 ₂ and the electromagnets 25 ₂ and 2
5 _{and 4} respectively.

Next, the control circuit for the electromagnet 25 and armature 26 is constructed as shown in FIG. A common inverter 27 is connected to the armatures 26 ₁ and 26 ₂ . To the input terminal of this inverter 27, static Leonards 28 ₁ , 28 ₂ , 28 ₃ , 28 ₄ each having a three-phase Gratz connection of a variable power source, such as a thyristor, are connected in parallel, and each Leonard 28 ₁ , 28 ₂ , 2
_{Electromagnets} 25 ₁ , _{25 2 ,}
25 ₃ and 25 ₄ are inserted in series. In the figure, numeral 31 is a DC smoothing reactor.

The stationary Leonard 28 ₁ , 28 ₂ , 28 ₃ ,
28 ₄ have gap length control circuits 29 ₁ , 29 ₂ ,
₂₉₃ and ₂₉₄ are connected. The gap length control circuits 29 ₁ , 29 ₂ , 29 ₃ , and 29 ₄ are provided with outputs from displacement meters 30 ₁ , 30 ₂ , 30 ₃ , and 30 ₄ , respectively.

In this case, displacement meters 30 ₁ , 30 ₂ , 30 ₃ , 30
₄ is provided for each electromagnet 25 ₁ , 25 ₂ , 25 ₃ , 25 ₄ , and the electromagnet 25 and rail 22
It generates an output according to the gap length between the two.

As a result, the gap length control circuits 29 ₁ , 29
₂ , 29 ₃ , 29 ₄ are the displacement meters 30 ₁ , 3 mentioned above.
At _the same time, the stationary Leonards 28 ₁ , 28 ₂ , 28 ₃ , 28 ₄ are phase-controlled in accordance with the outputs of the electromagnets 25 ₁ , 25 ₂ , 25 3 , 25 ₄ and the power supply to each electromagnet 25 1 , 25 ₂ , 25 ₃ , 25 ₄ is controlled. these leonard 28
The power supply to the armatures 26 ₁ and 26 2 is also controlled via the inverter 27 based on the output sum of the outputs _{1 ,} 28 ₂ , 28 ₃ , and 28 ₄ .

Here, the gap length control circuit 29 is specifically constructed as shown in FIG. For convenience of explanation, FIG. 6 shows a gap length control circuit 2 corresponding to an electromagnet ₂₅₁ .
9 I will explain about ₁ .

This gap length control circuit 29 ₁ introduces the output of the displacement meter 30 ₁ into one input terminal of a comparator 32 , and inputs the reference gap length signal x ₀ of the gap length setting device 33 into the other input terminal of this comparator 32 . It has been introduced. The comparator 32
The output ε ₁ is converted into ε ₂ via a series compensation element 34 and this signal ε ₂ is introduced into one input of a comparator 35 . Further, the output of the displacement meter ₃₀₁ is introduced into the other input terminal of the comparator 35 via the parallel compensation element 36. And this comparator 3
The output ε ₃ of the stationary Leonard 28 1 is used to control the control delay angle of the stationary Leonard 28 ₁ via the gate control circuit 37 . Here, the series compensation element 34 determines the rube gain of the control system, and in the case of proportional control, a simple amplifier is used, and in the case of integral control, an integrating circuit is used to make the steady-state deviation zero. Further, the parallel compensation element 36 compensates for the first derivative (velocity) and second derivative (acceleration) of displacement, and serves to stabilize the control system against excessive response of the control system. Note that an accelerometer may be used instead of the second-order differential of displacement.

Here, the series compensation element 34 will be explained as a simple amplifier (with a proportionality constant K). The setting value x _p is set in the setting device 33, and from the displacement meter ₃₀₁
If an output x ₁ is generated, the deviation ε
₁ = x ₁ - x ₀ is multiplied by K by the series compensation element 34,
ε ₂ =K·ε ₁ . Further, the displacement x ₁ is converted to x ₁ by the parallel compensation element 36 and becomes a signal of ε ₃ =ε ₂ +x ₁ via the comparator 35 . Therefore, the control delay angle of the gate control circuit 37 is controlled in accordance with the value of this output signal _ε3 , and as a result, a current corresponding to the control angle at this time is supplied to the electromagnet ₂₅₁ via the stationary Leonard ₂₈₁ . That will happen.

Here, for some reason, the output of displacement meter 30 ₁ x ₁
When becomes smaller, the control delay angle becomes larger and the levitation force is attenuated, and as a result, x ₁ is returned to its original value. Conversely, when the output x ₁ increases, the control delay angle at this time becomes smaller, the levitation force increases, and x ₁ returns to its original value.

In this way, the air gap length control circuit 29 ₁ is connected to the vehicle body 2.
The attraction force (levitation force) of the electromagnet 251 is controlled so that the electromagnet ₂₅₁ is supported floating with a constant gap length.

Of course, other gap length control circuits 29 ₂ , 29 ₃ , 29
₄ is also the same as above.

Therefore, the car body has electromagnets 25 ₁ , 25 ₂ , 25
It is supported floating in a balanced manner so that the gap length is constant at four points corresponding to ₃ , 25, _{and 4} .

Also, returning to FIG. 5, at this time the electromagnet 25
The sum of the currents flowing through the currents ₁ , 25 ₂ , 25 ₃ , and 25 ₄ is supplied to the armatures 26 ₁ and 26 ₂ via the reactor 31 and the inverter 27 .

By the way, it is known that in a linear induction machine, the attractive force Fx generated between the armature and the rail increases in proportion to the square of the above-mentioned current.

Therefore, the armatures 26 ₁ and 26 ₂ receive an attractive force Fx proportional to the square of the current at the vehicle body 23.
This occurs as a levitation force.

In this case, for example, displacement meters 30 ₁ , 30 ₂ , 30
Gap length control circuit 29 ₁ , detected at ₃ , 30 ₄
Each electromagnet 2 is activated by the operation of 29 ₂ , 29 ₃ , 29 ₄
The current to 5 ₁ , 25 ₂ , 25 ₃ , and 25 ₄ increases. Then, since the current flowing to the armatures 26 ₁ and 26 ₂ also increases, the armatures 26 ₁ and 26 ₂ act to reduce the overall gap length. Conversely, if the gap length decreases at the same time, the gap length control circuits 29 ₁ , 29
₂ , 29 ₃ , 29 ₄ , the current flowing to each electromagnet 25 ₁ , 25 ₂ , 25 ₃ , 25 ₄ decreases. Therefore, since the current flowing to the armatures 26 ₁ and 26 ₂ also becomes smaller, the armatures 26 ₁ and 26 ₂ act to increase the overall gap length. Furthermore, if the vehicle body 23 is tilted, even if an imbalance occurs in each gap length,
At this time, unless the total current flowing through the armatures 26 ₁ and 26 ₂ changes, the attractive force will not change. Therefore,
In this case, as described above, each electromagnet 25 ₁ , 25
₂ , 25 ₃ , and 25 ₄ , each gap length is controlled to be constant.

On the other hand, the frequency control circuit 3 is connected to the inverter 27.
Connect 91.

This frequency control circuit 391 introduces into the counter 42 the output pulses of the pulse generator 40 in a number proportional to the moving speed of the vehicle body 23 and the output pulses of the pulse oscillator 41 which sends out pulses of an arbitrary frequency. The counter 42 counts while adding both pulses when acceleration command X is introduced, sends an output every time the count value reaches n, and subtracts both pulses when deceleration command Y is introduced. While counting, an output is generated every time the count value reaches n. Then, the output signal of the counter 42 is given as an increment signal to a binary ring counter 43, and the contents of this ring counter 43 are sent to the logic circuit 4.
4, the forward rotation command F and reverse rotation command R are converted into six signals according to the forward rotation command F and the reverse rotation command R, and these six signals can be sent to each thyristor of the inverter 27 as a gate signal through a gate circuit 45.

In this case, the pulse generator 40 is set to send n pulses while the vehicle body 23 moves through 360 degrees in electrical angle, and the output frequency of the pulse oscillator 41 is set to n when the slip frequency is taken as the current slip frequency.
Set to [Hz].

Therefore, as an example, assuming that the pulse oscillator 41 is set to ・n・=6×20×2=240 [Hz], the moving speed of the vehicle body 23 is converted into a frequency r, and the value r=1 [Hz]. ] From the pulse generator 40, n = 6 x 20 x 1 = 120
A pulse of [Hz] will be generated, and a pulse of 240 [Hz] + 120 [Hz] = 360 [Hz] will be given to the counter 42, so the counter 42 will receive a pulse of 20×
Output is generated every 1/360=1/18 (second). Each time this output pulse is sent out, the mode of the inverter 27 advances by 60 degrees, so the mode of the inverter 27 returns to the original as 1/18 x 6 = 1/3 (seconds). This means that output is generated. Similarly, the speed of the vehicle body 23 increases and the output pulse of the pulse generator 40 becomes 240 times the above-mentioned value.
When [Hz] is generated, an AC output of 4 Hz will be generated from the inverter based on the same calculation as above. Therefore, the inverter frequency is equal to the pulse generator 4
It changes depending on the number of output pulses of 0, that is, the propulsion speed of the vehicle body 23. In this case, the slip frequency always matches the preset value=2 [Hz].
Therefore, a propulsive force is applied to the armatures 26 ₁ and 26 ₂ in accordance with the slip frequency at this time.

By the way, it is known that in a linear induction machine, the relationship between the levitation force Fx and the propulsive force Fg with respect to the slip frequency is as shown in FIG. Therefore, by setting the above-mentioned slip frequency within the range of FS shown, it is possible to obtain the desired propulsive force Fg under optimal conditions that take into account the levitation force Fx.

In this case, the region where the slip frequency is negative is when a deceleration force is applied to the armatures 26 ₁ and 26 ₂ .

Therefore, the propulsion force of the vehicle body 23 is controlled by the output frequency of the inverter 27, and the vehicle body 23 travels along the rails 22.

Thus, with such a configuration, the balance is maintained by the attractive force of the electromagnets divided into a plurality of parts, and the attracting force of the armature, which is controlled according to the total value of the current flowing through these electromagnets, provides levitation support and propulsion drive. Compared to conventional linear induction machines where the suction force acts in the direction of increasing vehicle weight, it is possible to reduce the weight of the vehicle as much as possible by eliminating unnecessary suction force. It is possible to reduce the capacity of the system and to significantly reduce power consumption. Furthermore, the levitation force of the armature at this time allows the electromagnet to be shaped accordingly, which can also greatly contribute to reducing the weight of the vehicle and saving labor. Furthermore,
Since electromagnets are inserted in series in the input circuit of the inverter, the inductance of these electromagnets can be used as reactance for current smoothing, so it is possible to omit the smoothing reactor, and even if it is provided, it can be small. It can be done.

It should be noted that the present invention is not limited to the above-mentioned embodiments, but can be implemented with appropriate modifications without changing the gist.
For example, in the above-described embodiment, a linear induction motor was described, but a linear reluctance motor or a hysteresis motor can also be used. In this case, in a reluctance motor, it is necessary to use a ferromagnetic material for the rail and to provide a notch at each pole pitch as a reaction device for generating propulsive force, and in a hysteresis motor, it is necessary to use a hysteresis material in the rail.

As described above, according to the present invention, it is possible to provide a magnetic levitation propulsion device that can be made lighter overall and reduce power consumption.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an example of a conventional magnetic levitation device, FIG. 2 is a configuration diagram showing the main parts of the device, FIG. 3 is a schematic configuration diagram showing an embodiment of the present invention, and FIG. 4 5 is a configuration diagram showing the main parts of the same embodiment.
The figure is a block diagram showing the control circuit of the same embodiment.
The figure is a block diagram showing a gap length control circuit used in the same embodiment, and FIG. 7 is a characteristic diagram for explaining the same embodiment. 1,21...Track, 2,22...Rail, 4...
... Secondary conductor, 5, 23 ... Vehicle body, 6, 24 ... Frame, 7, 25 ... Electromagnet, 8, 30 ... Displacement meter,
9, 29... air gap length control circuit, 10... variable power supply, 11... linear induction motor, 12... power supply,
26...armature, 27...inverter, 28...
Stationary Leonard, 31...Reactor, 32,3
5, 37... Comparator, 33... Gap length setting device, 3
4... Compensation element, 36... Coefficient setter, 38...
Current transformer, 39... Gate control circuit, 391... Frequency control circuit, 40... Pulse generator, 41...
Pulse oscillator, 42...Counter, 43...Ring counter, 44...Logic circuit, 45...Gate circuit.

Claims (1)

[Claims] 1. A pair of parallel rails, a movable body that can run along the rails, a plurality of electromagnets located opposite the rails of the movable body, and the rails of the movable body. an inverter that supplies alternating current output to the armature; a variable power source that supplies current to the electromagnet; and a frequency control circuit that controls the output frequency of the inverter. The current supplied to the armature is controlled via the inverter based on the total value of the current supplied to each of the electromagnets, and the movable body is propelled and supported while floating with a predetermined gap length. Features magnetic levitation propulsion device.