JPS5810956B2 - Linear motor power supply device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power supply device for a linear motor, and particularly to suppression of surge voltage when a changeover switch is open.

One drive system for high-speed land transportation is a linear synchronous motor (as shown in Figure 1), in which a superconducting magnet is mounted on the running body as a field and a propulsion coil is installed on the track.
There is a method (hereinafter abbreviated as LSM).

Two cycloconverters C each consisting of a Cyrisk converter are connected to multiple sections of propulsion coils LMn-1, LMn, LMn+1... installed on the track via changeover switches 5Wn-1, SWn, SW, +1..., respectively. /C1, C/C2, and the cycloconverter C/C, in response to a signal from the changeover switch opening/closing command 6, so as to supply power only to the propulsion coil where the traveling body 1 carrying the field magnet 2 is present. .

Operates one of the cycloconverters C/C1 and C/C2 with a signal from the position detector 5 that detects the position of the traveling object 1. A power supply system is used that determines which propulsion coils are to be powered and which propulsion coils are to be powered.

3.4 is a feeder, and 7 is an AC power source.

Propulsion coil LMn, depending on the position of the traveling body 1.

LMn, LMn+1..., selector switch 5wn-1°S
Wn, SWn+, ... and cycloconverter C/C
1. How the C/C2 operates will be explained with reference to the operation chart shown in FIG.

When the traveling body 1 is in the position ■, selector switch 5Wn-
1 is closed, and power is supplied from the cycloconverter C/C1 to the propulsion coil LMn via the feeder 3.

When the traveling body 1 advances to the position (■), the cycloconverter C/C2 is activated and power is started to be supplied to the propulsion coils LM and n via the changeover switch SW, which is already closed.

Between ■ and ■ when the traveling body 1 crosses between sections, the propulsion coil LM is operated by cycloconverters C/C1 and C/C22.
, , the power supply is controlled independently to each LMo.

When the traveling body 1 exits the propulsion coil LM at position ■, the gate of the cycloconverter C/C1, which had been feeding power until then, is shifted to zero, and the gate is suppressed to switch the cycloconverter C/C1 to zero. The operation of the propulsion coil LMn+1 is stopped and the changeover switch SWn, , 1 is opened in a non-current state, and the propulsion coil LMn+1 into which the traveling body 1 enters next.
The changeover switch SWo+1 is closed.

Between (1) and (2), the cycloconverter C/C2 supplies power only to the propulsion coil LMn via the changeover switch SW.

When the traveling body 1 comes to the position ■, the cycloconverter C/C1 is activated in the same way as in the state ■ mentioned above, and the propulsion coil L is switched on via the changeover switch SWn+1, which has been closed in advance.
Start feeding power to Mn+1.

Thereafter, the traveling body 1 is caused to travel by sequentially repeating the switching of the changeover switch and the control of the cycloconverter in the same manner.

In the operation of the changeover switch, the broken line indicates the command, and the solid line indicates the time when the changeover switch is opened or closed.

(Due to a delay in the operation of the selector switch).

In the above power supply system, the changeover switches connected to the same feeder are switched between the time the cycloconverter stops operating and the time it starts up again (between ■ and ■ in Figure 2).
It should be finished at .

By controlling the switching of the changeover switch as described above, the changeover switch can be opened and closed without electricity, and when the traveling body 1 runs astride two propulsion coils, the two cycloconverters C/C1°C/ Since each C2 controls the power supply independently, it has the advantage of extremely little thrust pulsation when crossing sections.

However, even if the cycloconverter stops operating, the AC power supply 7
Since a small current flows from the cycloconverter to the propulsion coil via the surge absorber and changeover switch,
When this current is cut off by a changeover switch, a surge voltage due to the internal inductance of each of the propulsion coil and feeder is generated between the contacts of the cutoff switch, resulting in generation of noise voltage such as radio noise.

SUMMARY OF THE INVENTION An object of the present invention is to provide a power supply device for a linear motor that eliminates the drawbacks of the prior art described above and can suppress surge voltage when a changeover switch is opened with a simple circuit configuration.

In order to achieve such an object, the present invention reduces the current flowing through the changeover switch after the cycloconverter stops operating, and then opens the changeover switch, thereby suppressing the surge voltage when the changeover switch is opened. I did it like that.

Hereinafter, a sister example of the present invention will be explained in detail with reference to the drawings.

Figure 3 is a circuit diagram and its operation diagram showing an embodiment in which the present invention is applied to a power supply device for a near motor, in which two cycloconverters alternately control power supply to multiple sections of propulsion coils, and its operation diagram is the same as in Figure 1. The symbols mean the same thing and their explanation will be omitted.

K1. K2 is an AC breaker, T1. 8. T2 is a power transformer, 8-11 are AC breakers consisting of a counter circuit and a memory circuit. 8 is an AC breaker with 2 open/close command circuits, 9 is an AC breaker with 1 open/close command circuit,
10 is a 2-open command circuit for the AC breaker, 11 is a 2-close command circuit for the AC breaker, and 20 is a crossing guide line installed on the track, with a receiver installed at one end of the transmission line mounted on the traveling body 1. The device detects the relative position of the field 2 mounted on the traveling body 1 and the propulsion coil by receiving constant frequency signals from the aircraft and the antenna.

To explain the operation of the circuit shown in FIG. 3, the tip of the traveling body 1 is t
At the position l, the command circuits 8 and 9 count the pulse from the crossing guide wire 20 as zero, and reset the memory circuit and counter circuit built into the command circuits 8 and 9, and
The command from the position detector 5 at time 1 activates the cycloconverter C/C2 where the traveling body 1 enters next, and the traveling body 1 moves to the digit position and the tip of the traveling body 1 enters the position t4. When this happens, the command circuit 10 sets the number of pulses from the cross guiding wire 20.
．． At step 11, it is counted as zero, and the memory circuit and counter circuit built in the command circuit 10 and 11 are reset, and the cycloconvection C into which the traveling object 1 next enters is determined by the command from the position detector 5 at time t4. /Start C1,
In addition, while the traveling body 1 is traveling through the propulsion coil LMn, the command circuit 1
0 and 11 do not count the number of pulses from the intersecting guide wire 20 and the traveling body 1 is traveling through the propulsion coil LMn+1, the command circuit 8,
9 is set so that the number of pulses from the crossing guide wire 20 is not counted.

When the tip of the traveling body 1 advances to the position t7, the same operation as at the time tl is performed, and at the position tlo, the same operation as at the time t4 is performed, and this is repeated sequentially thereafter to move the traveling body 1. run.

When the tip of the traveling body 1 enters the position t2, the traveling body 1 exits the propulsion coils LM, -1, so the command circuit 8 counts the number of pulses from the crossing guide wire 20 at this point, and the command circuit 8 outputs the However, this output simultaneously gives a command to stop the operation of cycloconverter C/C1 and a command to open AC breaker 1, and from this command Q, cycloconverter C/C1 is stopped and after a certain time delay, the AC breaker is turned on. 1 is opened.

On the other hand, when the traveling body 1 travels and enters the position t3, the command circuit 9 counts the number of pulses from the cross guiding wire 20, and the command circuit 9 outputs an output. A command to open the changeover switch 5Wo-1 and a command to close the changeover switch SW, + via the changeover switch opening/closing command 6 in order to prepare for power supply to the next propulsion coil LMn+1, and a command to close the changeover switch 1 to the AC breaker. A command is given, and after a certain time delay, the changeover switch 5Wo-1 is opened and the changeover switch S is opened.
1 is closed to Wo+1 and the AC breaker.

Furthermore, when the tip of the traveling body 1 focuses once on the position t4, the cycloconverter C/C, which had been stopped until now, stops.

When the traveling body 1 enters the propulsion coil LMo+1 by starting the operation, power is supplied to the propulsion coil LMn+1 via the changeover switch SW which has been closed in advance, and the traveling body 1 moves to the position t5. When entering, the command circuit 10 counts the number of pulses from the crossing guide wire 20 and outputs an output, which issues a command to stop the operation of the cycloconverter C/C2 and a command to open the AC breaker 2. is given at the same time, and with this command, cycloconverter C/C2 is stopped and AC breaker 2 is opened after a certain time delay.

On the other hand, when the traveling body 1 travels and enters the position t6, the command circuit 11 counts the number of pulses from the cross guiding wire 20, and the command circuit 11 outputs an output. In order to prepare for supplying power to the propulsion coils LM and +2, a command is given in advance to close the selector switch SWo+2 and a command to close the AC breaker 2, and this command causes the selector switch SWn to open after a certain time delay. Changeover switch SWn+2 and AC breaker 2 are both closed.

After the position t7, the above-described operations are repeated sequentially to move the traveling body 1.
is run.

As explained in detail above, for example, the time during which power is being supplied from the cycloconverter C/C2 to the propulsion coil LMo,
1 is opened to the AC breaker after the operation of the cycloconverter C/C stops, and the changeover switch 5Wn-1 is opened after a certain period of time has passed, so at the time the changeover switch 5Wn-1 is opened, the cycloconverter C/C Since the current from the surge absorber C1 is zero, the changeover switch S
It is safe because no surge voltage is generated between the contacts of W and 1.

In other words, according to the actual estimation, the AC breaker is opened after the operation of the cyclone converter stops, so the AC breaker is opened in a non-current state, and the changeover switch is opened after a certain period of time, so the AC When the circuit breaker is opened, the current flowing from the AC power supply through the power transformer to the surge absorber of the cycloconverter is interrupted.
In addition, the changeover switch is opened after the charge stored in the surge absorber of the cycloconverter is discharged through the secondary side of the power transformer or the propulsion coil, so when the changeover switch is opened, a surge voltage is generated between the contacts of the changeover switch. It has the advantage of being safe because it does not occur.

In the circuit shown in Figure 3, even if the cycloconverter is stopped, the excitation current flows through the power transformer, so when the AC breaker is opened, this excitation current is cut off, resulting in disadvantages such as roughening of the contacts of the AC breaker. There is.

FIG. 4 is a circuit diagram showing another embodiment of the present invention that eliminates the drawbacks of the circuit in FIG. 3. The same symbols as those in FIG. The circuits other than those shown in the figure are the same as the circuit shown in FIG. 3, and will therefore be omitted.

R1I R2 are resistors for suppressing the excitation current of the power transformer when the AC breaker Kl j K2 is open.

Next, to explain the operation of the circuit shown in Figure 4, the AC breaker is opened after the cycloconverter stops operating, but at this point a resistor is connected between the contacts of the AC breaker. The contacts do not become rough, and the change in current from the AC power supply 7 when the AC breaker is opened is small, so no surge voltage is generated when the AC breaker is opened.
It is safe and effective.

Figure 7 is a circuit diagram and its operation diagram showing another example of the present invention in which a resistor is connected to the output side of the cycloconverter before the changeover switch is opened to reduce the surge voltage when the changeover switch is opened. - The same symbols as in FIG. 6 mean the same things, and the explanation thereof will be omitted.

Next, the operation of the circuit shown in FIG. 5 will be explained, for example, when the preceding body 1 travels from the position tl to the position t5.

When the tip of the traveling body 1 has traveled to the position tl, the cycloconverter C/C2 is activated in order to prepare for supplying power to the propulsion coil LMn that will enter next based on a command from the position detector 5 at this point. .

When the traveling body 1 enters the position 12, the traveling body 1 exits the propulsion coil LMn-1, so the crossing guide line 2 at this point
The command circuit 8 counts the number of pulses from 0 and outputs it, and this output issues a command to stop the operation of the cycloconverter C/C1 and a command to turn on the switch S1 that connects the resistor R3 to the load side of the cycloconverter C/C1. Give at the same time.

When the traveling body 1 reaches the position t3, the command circuit 9 counts the number of pulses from the crossing guide line 20 at this point and outputs an output, which gives a command to open the changeover switch 5Wn-1.

When the traveling body 1 reaches position 14, the command circuit 12 counts and outputs the number of pulses from the cross guiding wire 20 at this point, and this output commands the opening of the switch S1 and the next propulsion coil LMn+1. At the same time, a command is given to close the selector switch SWn+1 in order to prepare for supplying power to the switch SWn+1.

When the traveling body 1 enters the propulsion coil LMo+1, the cycloconverter C/C1, which has been stopped until now, is activated, and when the traveling body 1 enters the propulsion coil LMo+1, t.
Changeover switch S closed after a certain time delay from point 4
It operates to supply power to propulsion coil LMn+1 via Wn+1.

From the position t6 to the position t8, the command circuits 10, 11 and 13 detect the number of pulses from the crossing guide line 20, and the same operation as described above is carried out, and this is repeated sequentially to cause the traveling body 1 to travel. Ru.

As explained in detail above, for example, during the period when power is being supplied from the cycloconverter C/C2 to the propulsion coil LM, when the cycloconverter C/C1 stops operating, the switch S1 is turned on and the cycloconverter C/C1
Flow the discharge current from the surge absorber into resistor R3,
In order to open the selector switch 5Wn-1 after a certain period of time, the current from the surge absorber of the cycloconverter C/C1 is decreasing at the time the selector switch SWn+1 is opened. Surge voltage generated between contacts can be reduced.

That is, according to this embodiment, a resistor is connected to the load side of the cycloconverter at the same time as the operation of the cycloconverter stops, and the changeover switch is then opened, so that the surge voltage generated between the contacts when the changeover switch is opened is reduced. Therefore, it is safe and effective.

Figure 5 shows a case where the AC power source 7 receives power directly from a commercial frequency power source or uses the output of a synchronous motor generator.
If the current flowing through the field winding is controlled so that the output voltage of the three-phase alternating current generator is reduced to the extent that the current flowing through the propulsion coil LMn does not change at the time point 2, the changeover switch will be easier than the circuit shown in Figure 5. The surge voltage generated between the contacts when SW, -1 is open is reduced.

In the above explanation, we have described a linear motor power supply device in which two cycloconverters alternately supply power to loads in multiple sections. Needless to say, the present invention can be applied to a system in which a converter applies voltage alternately to multiple sections of loads, and can also be applied to other circuit systems that can be modified and implemented as appropriate without changing the gist.

According to the present invention, it is possible to provide a power supply device for a linear motor that can suppress surge voltage when a changeover switch is open.

[Brief explanation of drawings]

Fig. 1 is a system diagram of a power supply device equipped with two cycloconverters or a near motor, Fig. 2 is an explanatory diagram of the operation of the system diagram in Fig. 1, and Fig. 3 is a block diagram showing an example of the present invention. FIG. 5 is a block diagram showing another example of the present invention and a diagram explaining its operation. DESCRIPTION OF SYMBOLS 1... Traveling object, 5... Position detector, 6... Changeover switch opening/closing command, 7... AC power supply, 8-13... Command circuit, 2
0...Cross induction wire, ACG...3-phase alternating current generator, C/
C1, C/C2...cycloconverter, FC...field current control device, K1. 2...AC breaker, LMn
-1, LM, LMn+1...propulsion coil, R1 to R4
...Resistance, Sl, S2...Switch, SW SW
, SWo+1...Selector switch, SM...Synchronous motor,
T1. T2...Power transformer.

Claims (1)

[Claims] 1. A running body equipped with a field of a linear motor, a plurality of propulsion coils of the near motor, a plurality of feeders, a plurality of propulsion coils of the near motor, a plurality of feeders, and a plurality of propulsion coils arranged adjacent to the feeder. a plurality of changeover switches that are repeatedly connected in sequence so as to connect the propulsion coil to a feeder different from the feeder to which the propulsion coil is connected; a plurality of power converters respectively connected to the plurality of feeders; In a power supply device for a linear motor that is equipped with a power supply and that supplies power only to a propulsion coil disposed at a position where the traveling body is present to cause the traveling body to travel, when the traveling body exits a certain propulsion coil, a first means for stopping a power converter supplying power to the propulsion coil; a second means for reducing the current flowing between the power converter and the propulsion coil when the power converter is stopped;
After the means operates, a third
A power supply device for a linear motor, characterized in that it is provided with means. 2. The power supply device for a linear motor according to item 1, wherein the second means is a breaker provided between the power source and the power converter, and a means for opening the breaker. 3. In the device described in item 1, the second means includes a breaker provided between the power source and the power converter, a resistor connected in parallel to the breaker, and a means for opening the breaker. A power supply device for a linear motor characterized by the following. 4. In the item described in item 1, the second means is a series circuit of a resistor and a breaker provided between the output terminals of the power converter, and a means for closing the breaker. Power supply device for linear motor.