JPS61154436A - Power source unit for nuclear fuser - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an improvement in a power supply device for a nuclear fusion device that requires reversing the current direction of a load coil.

[VL technical background of the invention] In general, in a nuclear fusion device, particularly in a tokamak-type fusion device, it is possible to reverse the current direction of the load coil in order to maintain plasma current generation and balance as a power supply device. It is necessary to use a suitable power supply.

FIG. 3 shows an example of the circuit configuration of this type of conventional power supply device for a nuclear fusion device. In the figure, 1 and 2 are two transformers that transform the output of an AC power supply (not shown) to a predetermined size, and 3 and 4 input the AC output from these transformers 1 and 2 separately. There are two thyristor converters connected in parallel to each other as forward and reverse converters that convert the DC current into direct current and supply it to the load coil 6, respectively. In addition, 5 is a cross current suppression reactor provided in series in the parallel circuit of each of these thyristor converters 3 and 4, and when the firing control angle of the thyristor converters 3 and 4 is rapidly advanced, the circulating current a becomes an overcurrent. This is to prevent this from happening. Although not shown in the drawings, a converter control device is actually provided that turns on each of the thyristor converters 3 and 4.

Next, we will explain the operation of reversing the current direction of the load coil 6 in this power supply device for a nuclear fusion device, as shown in FIG. Let's take an example.

First, during the period until the current direction of the load coil 6 is reversed from the positive direction to the negative direction, the forward thyristor converter 3 controls the current of the load coil 6, and the reverse thyristor converter 4 controls the loop shown in the figure. Current or circulating current a
constant control. On the other hand, after the current direction of the load coil 6 is reversed from the positive direction to the negative direction at the time 111to, the load coil 6 is
The forward thyristor converter 3 performs constant control of the circulating current a. 4 and 4 conceptually show that the control method of each thyristor converter 3.4 is switched before and after time to.

[Problems in the Background Art] However, in the conventional power supply device for a nuclear fusion device that uses the control method described above, although it has the advantage that the current direction of the load coil 6 is smoothly reversed, the following problems occur. There are problems like this. That is, it is necessary to provide a converter transformer for each thyristor converter 3.4, the cross-current suppression reactor 5 is essential, and in order to flow the circulating current a, it is necessary to provide a transformer for each thyristor converter 3.4. 4 and the current carrying capacity of the transformers 1 and 2 increases, and as a result, the power supply device becomes extremely large and irrationally expensive.

[Object of the Invention] The present invention was made to solve the above-mentioned problems, and its purpose is to easily reverse the current direction of the load coil while reducing the size and cost of the device and streamlining it. An object of the present invention is to provide a power supply device for a nuclear fusion device that is capable of

[Summary of the Invention] In order to achieve the above object, the present invention provides a nuclear fusion device in which it is necessary to reverse the current direction of a load coil, including one transformer that transforms an AC power output to a predetermined size;
Two converters are connected in antiparallel to each other, which commonly input the AC output from this transformer, convert it to DC, and supply it to the load coil, and the current direction of the load coil is positive or negative. a converter control device that controls the ignition of the one converter during a period in which the current direction is in the current direction, and controls the ignition of the other converter during a period when the current in the load coil reaches a zero point and the current direction is reversed to the negative direction or the positive direction; The present invention is characterized in that the polarity of the load coil current is changed by switching the converter controlled according to the current direction of the load coil. [Embodiment of the Invention] Hereinafter, an embodiment of the present invention shown in the drawings will be described.

FIG. 1 shows an example of the circuit configuration of a power supply device for a nuclear fusion device according to the present invention, and the same parts as in FIG. 3 are denoted by the same reference numerals. In the figure, 7 is a transformer (not shown) that transforms the output of an AC power supply to a predetermined size; 3.4
8 is a forward and reverse thyristor converter connected in parallel to each other that commonly inputs the AC output from the transformer 7, converts it into DC, and supplies it to the load coil 6; 8 is a current detector 9; Inputs the current of the load coil 6 detected by inputting the current, and controls the forward thyristor converter 3 during the period when the current direction is positive, and when the current of the load coil 6 reaches the zero point, the current direction is reversed to the negative direction. During this period, the converter control device controls the firing of the reverse thyristor converters 4, respectively. With the above configuration, the thyristor converter 3 or 4 to be controlled is switched according to the current direction of the load coil 6, and the load coil The polarity of the current is changed.

In the power supply device for a nuclear fusion device having such a configuration, the current of the load coil 6 is allowed to have a zero point period of approximately several milliseconds or more from time t1 to time t2, as shown in a in FIG.
The operation when reversing the current direction of the load coil 6 is as follows.

First, during a period in which the current direction of the load coil 6 is in the positive direction, the reverse direction thyristor converter 4 is gate-blocked, and the current of the load coil 6 is controlled by the forward direction thyristor converter 3. Thereafter, when it is detected that the current in the load coil 6 has reached the zero point, the forward thyristor converter 3 is gate-blocked, and after a predetermined period of time, the current direction in the load coil 6 is reversed from the positive direction to the negative direction. In contrast to the above, the reverse thyristor converter 4 is deblocked, thereby controlling the current of the load coil 6. As described above, the polarity of the load coil current 6 can be changed by switching the thyristor converter controlled according to the current direction of the load coil 6. Figures 2 and 2c show the forward thyristor converter 3 in the above operation. The current waveforms of the reverse thyristor converter 4 are shown respectively.

As mentioned above, the power supply device for a nuclear fusion device according to the present embodiment takes into account that some current intermittent period is allowed when the load coil current is reversed as the fusion device increases in size, and the output of the AC power source is increased. one transformer 7 that transforms into a predetermined size,
forward and reverse thyristor converters 3.4 connected in parallel to each other, which commonly input the AC output from the transformer 7, convert it into DC, and supply it to the load coil 6;
The current of the load coil 6 detected by the current detector 9 is input, and the forward thyristor converter 3 is controlled during the period when the current direction is positive, and when the current of the load coil 6 reaches the zero point, the current direction is changed. A converter control device 8 controls firing of each of the reverse direction thyristor converters 4 during a period in which the reverse direction is reversed.
The polarity of the load coil current is changed by switching the thyristor converter 3 or 4 controlled according to the current direction of the load coil 6.

Therefore, unlike in the past, each thyristor converter 3.4 is not energized at the same time, so it is possible to use a single transformer common to each thyristor converter 3.4, and circulating current control is possible. Each thyristor converter 3.4 and transformer 7
The current carrying capacity of the fusion device does not increase unnecessarily, and there is no need for a conventional cross-flow suppression reactor.For the above reasons, the result is an extremely compact, low-cost, and rational power source for fusion devices. You can get the equipment.

In the above embodiment, the case where the current direction of the load coil 6 is reversed from the positive direction to the negative direction has been described, but the present invention is not limited to this, and also applies to the case where the current direction of the load coil 6 is reversed from the negative direction to the positive direction. It goes without saying that it is possible to perform the same operation by controlling in the exact opposite manner to that described above.

Further, in the above embodiment, the converter is configured with a thyristor converter, but it is also possible to configure it using a semiconductor element other than this.

[Effects of the Invention] As explained above, according to the present invention, there is one transformer that transforms the AC power output to a predetermined size, and the AC output from this transformer is commonly input, but the AC output is converted to DC. Two converters connected in anti-parallel to each other convert and supply the current to the load coil, and during periods when the current direction of the load coil is positive or negative, the one converter converts and supplies the current of the load coil. and a converter control device that controls the firing of the other converter during the period when the current direction is reversed to the negative direction or the positive direction when the current direction reaches the zero point, and the converter is controlled according to the current direction of the load coil. Since the polarity of the load coil current is changed by switching the polarity of the current in the load coil, it is possible to reduce the size and cost of the device, as well as rationalize it, while also making it possible to easily reverse the current direction in the load coil.This is an extremely reliable nuclear fusion system. A II source device for the device can be provided.

[Brief explanation of the drawing]

Fig. 1 is a circuit configuration diagram showing an embodiment of the present invention, Fig. 2 is a current waveform diagram for explaining the operation in the same embodiment, and Fig. 3 is a circuit configuration diagram showing a conventional power supply device for a nuclear fusion device. figure,
FIG. 4 is a current waveform diagram for explaining the operation in FIG. 3. 1.2.7...Transformer, 3...Forward thyristor converter, 4...Reverse thyristor converter, 5...Cross current suppression reactor, 6... Load coil, 8... Converter control device, 9... current detector.

Claims (2)

[Claims] (1) In a fusion device that requires reversing the current direction of a load coil, one transformer transforms the AC power output to a predetermined size, and the AC output from this transformer is input in common. Two converters connected in antiparallel to each other convert this into DC and supply it to the load coil, and during periods when the current direction of the load coil is positive or negative, one converter and a converter control device that controls ignition of the other converter during a period when the current in the load coil reaches a zero point and the current direction is reversed to a negative direction or a positive direction, and according to the current direction of the load coil. A power supply device for a nuclear fusion device, characterized in that the polarity of a load coil current is changed by switching a converter to be controlled. (2) The power supply device for a nuclear fusion device according to claim (1), wherein the converter is a thyristor converter.