JPH09260099A - Particle accelerator power supply - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize the disturbance to the alternative current system at the time of occurrence of brake clown between acceleration electrodes, and to minimize the restarting time. SOLUTION: When a brake down is occurred between acceleration electrodes 6 if an inverter 3 stops, the consumption power supplied from the converter 1 will be dissipated at the power consumption circuit 15. In this case the charge stored in the smoothing capacitor 2 is held by a reverse-current breaking diode 11. Thus when the inverter 3 stops, the alternative current system is not disturbed, also the input voltage of the inverter 3 is held to a predetermined voltage so that the restart of the inverter 3 will be in shorter time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a particle acceleration power supply device for supplying a DC power supply to an acceleration electrode for accelerating charged particles.

[0002]

2. Description of the Related Art For example, a neutron particle injection heating device used for heating plasma of a nuclear fusion device is constructed as shown in FIG. A direct current high voltage is applied to the acceleration electrode 6 in advance, and the charged particle generation power supply device 8 is activated to cause the ion source 7 to generate charged particles. Then, it is accelerated by the potential difference between the acceleration electrodes 6.

The particle acceleration power supply device 14 is a power supply device for accelerating the charged particles generated by the ion source 7, and the acceleration electrode 6
DC power is supplied between them. That is, the AC power supply is converted into DC by the converter 1, the DC converted by the converter 1 is smoothed by the smoothing capacitor 2, and the DC is input to the inverter 3. The inverter 3 inversely converts the direct current smoothed by the smoothing capacitor 2 into a high-frequency alternating current, and the alternating current inversely converted by the inverter 3 is boosted by the step-up transformer 4. The alternating current stepped up by the step-up transformer 4 is rectified by the rectifier 5, and the rectified direct current is supplied to the acceleration electrode 6 as a direct current power source.

Here, a dielectric breakdown phenomenon, which is often referred to as a breakdown and is equivalent to a load short circuit, occurs between the acceleration electrodes 6. When a breakdown occurs between the acceleration electrodes 6,
In order to protect the ion source 7 and the particle acceleration power supply device 14 from the surge current generated at that time, it is necessary to cut off the direct current supplied to the acceleration electrode 6 at high speed.

As a countermeasure against this, it is conceivable to provide a switch on the DC side. In such a case, however, the particle acceleration power supply voltage is high, so the number of switching elements in series increases and the switch becomes large. Further, as the size of the switch becomes larger, there arises a problem of its installation place.

In order to avoid this, the particle acceleration power supply unit 14
Has an inverter system configuration as shown in FIG. That is, when a breakdown occurs, the AC side inverter 3 switches at high speed to cut off the DC current.

[0007]

However, in such an inverter type particle acceleration power supply device 14, a disturbance may be generated in an AC system which is an AC power supply.
That is, when the breakdown occurs, the inverter 3 is shut off at high speed, so that the power consumption that has been used up to that point is suddenly lost, causing a disturbance in the AC system.

When the inverter is shut down at high speed by a breakdown and stopped, and then restarted, the inverter 3 cannot be started until the input voltage of the inverter 3 rises to a predetermined voltage. ,
It took some time to restart the particle acceleration power supply device 14.

An object of the present invention is to provide a particle accelerating power supply device capable of minimizing disturbance to the AC system when breakdown occurs between the accelerating electrodes and enabling restart in the shortest time. .

[0010]

According to a first aspect of the present invention, there is provided a power consumption circuit for consuming DC power converted by a converter when an inverter stops, and a charge stored in a smoothing capacitor when the inverter stops. And a backflow prevention diode for preventing the power from being supplied to the power consumption circuit.

According to the first aspect of the present invention, when the inverter is stopped when the breakdown between the acceleration electrodes occurs, the power consumption supplied from the converter is consumed by the power consumption circuit.
Further, the electric charge stored in the smoothing capacitor at that time is held by the backflow prevention diode. Therefore, when the inverter stops, the AC system is not disturbed, and the input voltage of the inverter can be maintained at a predetermined voltage.

According to a second aspect of the present invention, in the first aspect of the present invention, the power consuming circuit includes a switch which is turned on when the inverter is stopped, and a resistor which is connected in series to the switch and consumes the DC power converted by the converter. It is composed of a vessel.

According to the second aspect of the invention, the switch is closed when the inverter is stopped. As a result, the DC power supplied from the converter is consumed by the resistor.

[0014] The invention of claim 3 is claim 1 or claim 2.
In the invention, the switch is a reverse blocking thyristor.

According to the invention of claim 3, in addition to the operation of the invention of claim 1 or claim 2, a gate pulse is output to the reverse blocking thyristor at the same time as the gate pulse for stopping the inverter to make the reverse blocking thyristor conductive. . Therefore, there is almost no time difference between the stop of the inverter and the conduction of the reverse blocking thyristor.

The invention of claim 4 is claim 1 or claim 2.
In the invention, the switch is a gate turn-off thyristor.

According to the invention of claim 4, in addition to the operation of the invention of claim 1 or claim 2, a gate pulse is output to the gate turn-off thyristor at the same time as the gate pulse for stopping the inverter to make the gate turn-off thyristor conductive. On the other hand, when the inverter is restarted, a gate pulse for turning off is output to the gate turn-off thyristor to make the gate turn-off thyristor non-conductive. Therefore, there is almost no time difference between the stop of the inverter and the conduction of the reverse blocking thyristor, and it is not necessary to stop the converter when restarting the inverter.

The invention of claim 5 is the invention of claim 1 or claim 2.
In the invention, a plurality of power consumption circuits are connected in parallel,
A plurality of power consumption circuits are sequentially switched and used each time the inverter is stopped.

According to the invention of claim 5, in addition to the operation of the invention of claim 1 or 2, a plurality of power consumption circuits are sequentially switched and used every time the inverter is stopped. Therefore, each power consuming circuit can be rated for a short time.

[0020]

Embodiments of the present invention will be described below. FIG. 1 is a configuration diagram showing a first embodiment of the present invention. In the first embodiment, a power consumption circuit 15 including a switch 9 and a resistor 10 is connected between the converter 1 and the smoothing capacitor 2 in parallel with the conventional example shown in FIG. A backflow prevention diode 11 is connected in series between the power consumption circuit 15 and the smoothing capacitor 2.

That is, when a breakdown occurs between the acceleration electrodes 6 and the inverter 3 stops, the converter 1
The power consumption circuit 15 consumes the power supplied from. Further, the backflow prevention diode 11 blocks discharge of the electric charge stored in the smoothing capacitor 2 at that time. This allows
When the inverter 3 is stopped, the AC system connected to the converter 1 is not disturbed, and the input voltage of the inverter 3 is maintained at a predetermined voltage.

When the particle accelerating power supply device 14 is applying a DC voltage to the accelerating electrode 6, the converter 1 is supplying the electric power consumed by the accelerating electrode 6. In this state, the switch 9 of the power consumption circuit 15 is open, and the power consumption circuit 15 does not consume power.

When a breakdown occurs, the inverter 3 is stopped and at the same time the power consumption device 15
The switch 9 is closed. By stopping the inverter 3, the power consumed by the acceleration electrode 6 becomes surplus power. This surplus power is consumed by the resistor 10 by closing the switch 9 of the power consumption circuit 15. That is, by closing the switch 9, a current flows through the resistor 10 and power is consumed. Since the converter 1 is not stopped in this state, the power supplied from the converter 1 is continuously consumed by the resistor 10.

On the other hand, when the switch 9 of the power consumption circuit 15 is closed, the electric charge stored in the smoothing capacitor 2 by the backflow prevention diode 11 is not attenuated. Therefore, the input voltage of the inverter 3 is always kept constant.

Next, when the breakdown is settled, the converter 1 is temporarily stopped at that point and the switch 9 is opened. Then, the particle acceleration power supply device 14 is restarted. That is, the converter 1 and the inverter 3 are activated. At this time, since the smoothing capacitor 2 is already in the charging completed state, the input voltage of the inverter 3 is always kept constant, so that the particle acceleration power supply device 14 can be restarted in the shortest time. .

According to the first embodiment, when the breakdown occurs, the resistor 10 of the power consumption circuit 15 temporarily consumes the surplus power due to the stop of the inverter 3.
There is no sudden change in power consumption. Therefore, it is possible to minimize the disturbance to the AC system to which the converter 1 is connected. Further, even if excess power is consumed by the power consumption device 15, the charge of the smoothing capacitor 2 is not attenuated, so that the particle acceleration power supply device 14 can be restarted in the shortest time.

Next, FIG. 2 shows a second embodiment of the present invention. FIG. 2 is a configuration diagram showing a second embodiment of the present invention. The second embodiment is different from the first embodiment shown in FIG. 1 in that the switch 9 has a reverse blocking thyristor (S).
CR) 12 and outputs a gate pulse to the reverse blocking thyristor 12 at the same time as the gate pulse for stopping the inverter 3 to make the reverse blocking thyristor 12 conductive.

When the particle accelerating power supply device 14 is applying a DC voltage to the accelerating electrode 6, the converter 1 is supplying the electric power consumed by the accelerating electrode 6. In this state, the reverse blocking thyristor of the power consumption circuit 15 is non-conductive, and the resistor 10 of the power consumption circuit 15 does not consume power. And when a breakdown occurs,
At the same time as the gate pulse for stopping the inverter 3,
Since a gate pulse is output to the reverse blocking thyristor 12,
The inverter 3 stops and at the same time the reverse blocking thyristor 12
Conducts.

When the inverter 3 is stopped, the power consumed by the acceleration electrode 6 becomes surplus power, which is consumed by the resistor 10 when the reverse blocking thyristor 12 of the power consumption circuit 15 is turned on. Will be done. Since the converter 1 is not stopped in this state,
The power supplied from the converter 1 continues to be the resistor 10
Will be consumed.

On the other hand, even if the reverse blocking thyristor 12 of the power consumption circuit 15 is turned on, the charge stored in the smoothing capacitor 2 by the backflow prevention diode 11 is not attenuated, so that the input voltage of the inverter 3 is always kept constant. Be drunk

Next, when the breakdown is settled, the converter 1 is temporarily stopped at that time and the reverse blocking thyristor 12 is stopped.
Is turned off. Then, the particle acceleration power supply device 14 is restarted. That is, the converter 1 and the inverter 3 are activated. At this time, since the smoothing capacitor 2 is already in the charging completed state, the input voltage of the inverter 3 is always kept constant, so that the particle acceleration power supply device 14 can be restarted in the shortest time. .

According to the second embodiment, since the switch 9 is the reverse blocking thyristor 12, there is almost no time difference between the stop of the inverter 3 and the conduction of the reverse blocking thyristor, and the occurrence of transient overvoltage can be suppressed. You can Further, since power is temporarily consumed by the resistor 10 when a breakdown occurs, it is possible to minimize a disturbance to the AC system without causing a sudden change in power consumption. Further, since the electric charge of the smoothing capacitor 2 is not attenuated, the particle acceleration power source 1
4 can be restarted in the shortest time.

FIG. 3 shows a block diagram of the third embodiment of the present invention. In this third embodiment, a gate turn-off thyristor (GTO) 13 is used instead of the reverse blocking thyristor 12 in the second embodiment shown in FIG.

Then, a gate pulse is output to the gate turn-off thyristor 13 simultaneously with the gate pulse for stopping the inverter 3, and the gate turn-off thyristor 1 is output.
Conduct 3 On the other hand, when the inverter 3 is restarted, a gate pulse for turning off is output to the gate turn-off thyristor 13 to make the gate turn-off thyristor 13 non-conductive. That is, the converter 1 need not be stopped when the particle acceleration power supply device 14 is restarted. Since other configurations are the same as those of the second embodiment shown in FIG. 2, the same elements are designated by the same reference numerals and the description thereof will be omitted.

According to the third embodiment, since the switch 9 is the gate turn-off thyristor 13,
The current flowing through the resistor 10 of the power consumption circuit 15 can be interrupted while the converter 1 is always operating. Further, there is almost no time difference between the stop of the inverter 3 and the conduction of the gate turn-off thyristor 13, so that transient overvoltage generation can be suppressed.

Further, since power is temporarily consumed by the resistor 10 when a breakdown occurs, a rapid change in power consumption does not occur and disturbance to the AC system can be minimized. Since the backflow prevention diode 11 does not attenuate the charge of the smoothing capacitor 2, the particle acceleration power supply device 1
4 can be restarted in the shortest time.

FIG. 4 shows a block diagram of the fourth embodiment of the present invention. The fourth embodiment is the same as the first embodiment shown in FIG.
In contrast to the embodiment described above, a plurality of power consumption circuits 15 are connected in parallel, and the plurality of power consumption circuits 15 are sequentially switched and used each time the inverter is stopped.

When the particle accelerating power supply device 14 is applying a DC voltage to the accelerating electrode 6, the converter 1 is supplying the electric power consumed by the accelerating electrode 6. In this state, all the switches 9 of the power consumption circuits 15 are open, and the power consumption circuit 15 does not consume power.
When a breakdown occurs, the inverter 3 is stopped and at the same time, the switch 9 of one power consumption device 15 in the order of use is closed. That is, the plurality of power consumption devices 15 are sequentially switched and used each time the inverter 3 is stopped due to breakdown.

Next, by stopping the inverter 3, the power consumed by the acceleration electrode 6 becomes surplus power.
This surplus power is consumed by the power consumption circuit 1 in which the switch 9 is closed.
It is consumed by the resistor 10 of 5. Since the converter 1 is not stopped in this state, the electric power supplied from the converter 1 is continuously consumed by the resistor 10.

On the other hand, even if the switch 9 of any of the plurality of power consumption circuits 15 is closed, the charge stored in the smoothing capacitor 2 by the backflow prevention diode 11 is not attenuated, so that the input voltage of the inverter 3 is reduced. Is kept constant at all times.

When the breakdown is settled, the converter 1 is temporarily stopped at that point and the switch 9 which is closed is opened. Then, the particle acceleration power supply device 14 is restarted. That is, the converter 1 and the inverter 3 are activated. At this time, since the smoothing capacitor 2 is already in the charging completed state, the input voltage of the inverter 3 is always kept constant, so that the particle acceleration power supply device 14 can be restarted in the shortest time. .

According to the fourth embodiment, the switches 9 for closing are sequentially switched one by one at each occurrence of the breakdown, so that when the breakdown repeatedly occurs, another power consumption circuit 15 is provided. Will be used. Therefore, the time rating of the switch 9 and the resistor 10 of the power consumption circuit 15 can be short-time rating.

Further, since the switches 9 are not connected in multiple parallel and operated at the same time, current concentration due to switching operation time difference and current imbalance due to variation in resistance value when resistors 10 are connected in parallel are caused. It never happens.

[0044]

As described above, according to the present invention, even if the inverter is stopped when the breakdown occurs, the power consumption circuit consumes the power supplied from the converter, so that the power consumption does not change suddenly. . As a result, it is possible to minimize disturbance to the AC system to which the converter is connected.

Further, when the inverter is stopped at the time of breakdown and the power consumption circuit is formed, the input voltage of the inverter is held constant by the backflow prevention diode, so that the restarting of the inverter can be performed in the shortest time. It is possible to minimize the startup time of the particle acceleration power supply device.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing a second embodiment of the present invention.

FIG. 3 is a configuration diagram showing a third embodiment of the present invention.

FIG. 4 is a configuration diagram showing a fourth embodiment of the present invention.

FIG. 5 is a configuration diagram of a conventional example.

[Explanation of symbols]

 1 Converter 2 Smoothing Capacitor 3 Inverter 4 Step-up Transformer 5 Rectifier 6 Accelerating Electrode 7 Ion Source 8 Charged Particle Generation Power Supply Device 9 Switch 10 Resistor 11 Backflow Prevention Diode 12 Reverse Blocking Thyristor 13 Gate Turn-Off Thyristor 14 Particle Acceleration Power Supply Device 15 Power Consumption circuit

Claims (5)

[Claims] 1. A particle acceleration power supply device for supplying a DC power supply to an accelerating electrode for accelerating charged particles generated by an ion source, the converter accelerating an AC power supply into a DC power supply.
A smoothing capacitor for smoothing the direct current converted by the converter; an inverter for inversely converting the direct current smoothed by the smoothing capacitor into high-frequency alternating current by the inverter; and a step-up transformer for boosting the alternating current reversely converted by the inverter. In a particle overspeed power supply consisting of a rectifier that rectifies alternating current boosted by the boosting transformer and supplies direct current power to the acceleration electrode, in order to consume the direct current power converted by the converter when the inverter stops. And a backflow prevention diode for preventing the electric charge stored in the smoothing capacitor from being supplied to the power consumption circuit when the inverter is stopped. apparatus. 2. The power consuming circuit comprises a switch that is turned on when the inverter is stopped, and a resistor that is connected in series with the switch and consumes the DC power converted by the converter. The particle acceleration power supply device according to claim 1. 3. The particle acceleration power supply device according to claim 1, wherein the switch is a reverse blocking thyristor. 4. The particle acceleration power supply device according to claim 1, wherein the switch is a gate turn-off thyristor. 5. The power consumption circuit according to claim 1, wherein the plurality of power consumption circuits are connected in parallel, and each time the inverter is stopped, the plurality of power consumption circuits are sequentially switched and used. 2. The particle acceleration power supply device according to 2.