JP5363786B2 - Superconducting coil power supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simple and inexpensive method for abruptly changing a current flowing to a superconducting coil. <P>SOLUTION: A plurality of DC power supplies are connected in series to set a first power supply at a low-voltage continuous rating and to set a second power supply connected in series at a high voltage short-time rating. When a switch of a continuous rating is connected to the output of the second power supply in parallel to abruptly change the current of the superconducting coil, the switch is opened to flow the current via the first and second power supplies. When making a steady-state current flow, the switch is closed to make the current flow only via the first power supply. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

The present invention relates to a large-capacity DC power supply system that generates a high magnetic field by supplying a large current to a superconducting coil, and normally supplies a steady current to the superconducting coil to generate a high voltage during a required period. Thus, the present invention relates to a power supply system that makes it possible to sharply change the energization current of the superconducting coil.

In a fusion experimental device, a magnetic field generating coil that controls a magnetic field to confine plasma and generates a strong magnetic field is required. In a large experimental device, a superconducting coil is used as the magnetic field generating coil. Yes.

Excitation of the superconducting coil requires a large current, and during the period of exciting the plasma or moving the position of the plasma, a high voltage is applied to the superconducting coil so that the energizing current is steep. It is necessary to change to.

  As a power supply system for energizing the magnetic field generating coil, for example, the one shown in FIG. 10 is known. In the conventional example shown in FIG. 10, a load coil 11 and a resistor 12 are both provided with a high voltage small current power source 13 and a low voltage large current power source 14 which are thyristor power sources, and open / close switches 15 to 17. In the power supply system for the fusion device, during the high voltage generation period, the open / close switches 15 and 17 are turned on and the open / close switch 16 is turned off, and the high voltage / low current power supply 13 is connected to the load coil 11. 13 power is supplied to the load coil 11.

  When the low voltage high current power source 14 is connected to the load coil 11, the output voltage of the high voltage small current power source 13 is throttled, the open / close switch 16 is turned on, and the current of the load coil 11 is transferred to the open / close switch 16. Next, by utilizing the low-voltage high-current power supply 14 and turning off the open / close switch 17, the current of the load coil 11 is commutated to the low-voltage high-current power supply 14.

According to the above configuration, the high voltage small current power source 13 is connected to the load coil 11 during the high voltage generation period, power is supplied from the high voltage small current power source 13 to the load coil 11, and the low voltage is generated during other periods. Since the large current power source 14 is connected to the load coil 11 and power can be supplied from the low voltage large current power source 14 to the load coil 11, the capacity of both power sources 13 and 14 can be reduced (Patent Document). 1).
JP-A-3-2593

  However, in the power supply system for the nuclear fusion device, it is possible to switch the current path in the energized state by using the circuit breaker or the input device having the current interruption capability as the on / off switches 16 and 17. Such a circuit breaker or charging device is generally large and expensive, and a plurality of circuit breakers are required. Therefore, there is a problem that the power supply system as a whole is increased in size and the equipment cost is increased.

  If a high voltage power supply can be connected in series with a low voltage large current power supply during a high voltage generation period, that is, a period requiring a high voltage and operated simultaneously, the voltage applied to the load coil 11 can be Since the current power supply and the high voltage power supply can be shared, the output voltage of the high voltage power supply can be reduced, and the high voltage power supply can be reduced in size and cost.

  However, in the conventional example, since both the power sources 13 and 14 cannot be operated simultaneously, the equipment capacity of the high voltage small current power source 13 becomes large, and it is difficult to reduce the size and cost.

  Therefore, the present invention has been made to solve such a problem, and is required to continuously energize a large current with a simple circuit configuration and using small and inexpensive components. An object is to provide a power supply system capable of generating a high voltage during a period.

The first aspect of the present invention is that a first power source having a low voltage continuous rating and a second power source having a high voltage short-time rating are connected in series, and a continuous rated switch is connected to the output of the second power source. In a large-capacity DC power supply system configured by connecting in parallel, when shifting from a state in which the superconducting coil is energized only by the first power source to a state in which current is energized by the first power source and the second power source Changes the output voltage of the second power supply to control the current flowing through the switch to be zero, and opens the switch when the current flowing through the switch is less than a predetermined value. In addition, when the current is supplied to the superconducting coil with the first power supply and the second power supply, the second power supply is negative. After the voltage is output, the switch is closed and the current flowing through the second power source And controlling to switch the road to the switch.

  According to the first aspect of the present invention, when a steady current is applied to the superconducting coil, the superconducting coil is energized via the switch only by the first power source, and the current of the superconducting coil is sharply increased. When changing the voltage, the first power supply and the second power supply output voltage, and the output voltage of both power supplies is added so that a high voltage can be applied to the superconducting coil. It is possible to provide an inexpensive power supply system.

According to the first aspect of the present invention, when the current path is switched while the superconducting coil is energized, the output voltage of the second power source is controlled so that the current of the switch becomes zero. to opening the later switch, since no current flows through the switch at the time of opening, it is not necessary to use a large and expensive switch having a current interrupting capability, also require multiple switches Therefore , the equipment can be downsized and the cost can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. FIG. 1 is a circuit diagram showing an entire power supply system A for a magnetic field generating coil according to the present invention. In FIG. 1, reference numeral 1 denotes a DC power source (hereinafter referred to as a steady power source) which is a low voltage continuous rating.

  Reference numeral 3 denotes a small and inexpensive switch having no current interruption capability. Reference numeral 4 denotes a DC current transformer connected in series to the switch 3, and detects a current flowing through the switch 3.

In this embodiment, the switch 3 is a device having no breaking capability. However, the switch 3 can be constituted by a breaker having a current breaking capability in addition to this embodiment.

In addition to the above, it is also possible to use a semiconductor switch element such as a thyristor or IGBT for the switch 3.

  Reference numeral 5 denotes a superconducting coil connected in series to a series circuit composed of the stationary power source 1, the switch 3 and the DC current transformer 4. For example, the method according to the present invention is used in a power source system for a fusion apparatus. In this case, a magnetic field generating coil for generating a magnetic field in the nuclear fusion reactor is applicable.

  Reference numeral 6 denotes a DC power source (hereinafter referred to as a pulse power source) composed of a high-voltage short-time rated thyristor converter that applies a high voltage to the superconducting coil, and a pulse is interposed between the steady power source 1 and the superconducting coil 5. The negative side of the power source 6 is connected to the positive side of the stationary power source 1, the positive side of the pulse power source 6 is connected in series with the superconducting coil 5, and connected in parallel to a series circuit consisting of the switch 3 and the DC current transformer 4. ing.

  Further, the pulse power supply 6 includes a control unit (not shown) that controls the pulse power supply 6 and the switch 3 in response to a command from a control computer (not shown).

  According to the method of the present invention, it is possible to operate by connecting the pulse power source 6 in series to the stationary power source 1 with the simple component configuration as described above, and a high voltage is applied to the superconducting coil 5 at a desired timing. Therefore, one application example is the use of the power supply system for the fusion apparatus.

  In a fusion device, it is necessary to pass a large current through the magnetic field generating coil in order to create a magnetic field for confining the plasma, and when the plasma is excited or controlled, the magnetic field generating coil is short. Since it is necessary to apply a high voltage for a long time, the present invention is a method suitable for use in a power supply system used for the application (for plasma control).

  Below, the case where the serial connection method of the pulse power supply which concerns on this invention is utilized for a nuclear fusion apparatus is demonstrated. The technical scope of the present invention is not limited to use in a power supply system for a fusion device, but can be used in any application having the purpose of abruptly changing the current applied to a superconducting coil. Of course it is.

  2-8 is explanatory drawing which shows the transition of the driving | running operation | movement of the power supply connected in series by applying this invention in time series. Moreover, in FIGS. 2-7, the direction of the arrow which does not comprise the closed loop has shown the direction of the positive direction of a voltage or an electric current. The arrows constituting the closed loop indicate the current flow.

FIG. 2 shows the state of the entire power supply system A during normal plasma control, that is, during steady operation, the switch 3 is in a closed state, and the pulse power supply 6 is in a state where the firing angle is larger than 90 °. Waiting in (gate shift state).

  At this time, the current Isw flows from the steady power source 1 to the superconducting coil 5 via the switch 3 in the direction of the arrow shown in FIG. 2, and the superconducting coil 5 generates a magnetic field in the fusion reactor (steady operation state). .

  Next, when it is necessary to apply a high voltage to the superconducting coil 5 to change the energized current sharply (pulse operation), a control computer (not shown) outputs a pulse operation command and performs control. In response to this, the unit (not shown) changes the output voltage Vpls of the pulse power supply 6 and controls the current Isw flowing through the switch 3 to be zero (see FIG. 3).

  As a result, the current Isw flowing through the switch 3 becomes zero as shown in FIG. 3, the current Icon of the steady power supply 1 and the current Ipls of the pulse power supply 6 have the same current value, and the current flowing through the superconducting coil 5. Ic.

  The control unit (not shown) detects the current of the switch 3 with a DC current transformer 4 connected in series with the switch 3, so that when the current becomes zero, the controller 3 The electrode is opened as shown in FIG.

  The steady power supply 1 and the pulse power supply 6 receive voltage command values from the control computer (not shown), change their output voltages, and add the output voltages of both power supplies 1 and 6 together. Is applied to the superconducting coil 5 and the current changes abruptly (pulse operation state).

  Next, when transitioning to the steady operation state, in the pulse operation state shown in FIG. 4, when the control computer (not shown) outputs a steady operation command, the control unit (not shown) receives this. Thus, the output voltage Vpls of the pulse power supply 6 is controlled to a predetermined negative voltage (for example, −5 [V]) (see FIG. 5).

On the other hand, the steady power supply 1 outputs an output voltage in accordance with a voltage command value from the control computer (not shown).

  When the output voltage Vpls of the pulse power supply 6 reaches a predetermined voltage (for example, −5 [V]), the control unit (not shown) closes the switch 3 as shown in FIG. Then, the current Isw flowing through the switch 3 increases and the output current Ipls of the pulse power source 6 decreases. Finally, the output current Ipls of the pulse power supply 6 becomes zero.

  Thereafter, the control unit (not shown) sets the ignition angle of the pulse power source 6 to be greater than 90 ° (gate shift), and thereby changes from the pulse operation state (FIG. 4) to the steady operation state. The transition is completed (see FIG. 7).

  FIG. 8 is a timing chart showing a current waveform or a voltage waveform in each component of the entire power supply system A during the state transition between the steady operation state and the pulse operation state described above.

  FIG. 8A shows the waveform of the output voltage Vcon in the steady power supply 1, and FIG. 8B shows the waveform of the output current Icon in the steady power supply 1.

  FIG. 8C shows the waveform of the output voltage Vpls in the pulse power supply 6, and FIG. 8D shows the waveform of the output current Ipls in the pulse power supply 6.

  FIG. 8E shows the open / close state of the switch 3, and FIG. 8F shows the waveform of the current Isw flowing through the switch 3.

  FIG. 8G shows the waveform of the voltage Vc in the superconducting coil 5, and FIG. 8H shows the waveform of the current Ic flowing in the superconducting coil 5.

  Hereinafter, the voltage or current waveform of each component of the entire power supply system A and the state of change in the switching state of the switch 3 during the state transition described above will be described with reference to FIG.

  The output current Icon of the steady power supply 1 and the current Ic flowing through the superconducting coil 5 are the same.

  In a steady operation state (period (1)), the steady power supply 1 applies an output voltage to the superconducting coil 5 according to a voltage command value from the control computer (not shown), while the pulse power supply 6 is in a state where the ignition angle is larger than 90 ° (gate shift state), and the switch 3 is in a closed state. Here, when a pulse operation command is input from the control computer (not shown) to the control unit (not shown), the output voltage Vpls of the pulse power supply 6 is changed as shown in FIG. 8 (c). Control is performed so that the current Isw flowing through the switch 3 becomes zero (period (2)).

  As a result, the output current Ipls of the pulse power supply 6 increases to the current value of the superconducting coil 5. At this time, the current Isw flowing through the switch 3 decreases and becomes zero (period (2)). By detecting the current Isw with the DC current transformer 4, the control unit (not shown) opens the switch 3 when the current Isw becomes zero (see FIG. 8E). (3), (4)).

  Thereafter, according to the voltage command value from the control computer (not shown), the output voltage Vcon of the steady power supply 1 increases as shown in FIG. 8A, and the output voltage Vpls of the pulse power supply 6 increases as shown in FIG. . As a result, the voltage Vc applied to the superconducting coil 5 also increases rapidly (period (5)) as shown in FIG. As a result, the current Ic flowing through the superconducting coil 5 can be changed sharply as shown in FIG. 5H, and can be effectively used for plasma control in the fusion apparatus.

  When transitioning from the pulse operation state to the steady operation state, when a steady operation command is input from the control computer (not shown) to the control unit (not shown), the pulse power supply 6 sets its output voltage Vpls to a predetermined value. To a negative voltage (−5 [V] in this embodiment) (period (6)). On the other hand, the stationary power supply 1 outputs a voltage according to a voltage command value from the control computer (not shown) (period (6)).

  When the output voltage Vpls reaches a predetermined value (−5 [V]), when the control unit (not shown) closes the switch 3, the current Isw flowing through the switch 3 increases and pulses. The output current Ipls of the power supply 6 decreases (period (7)).

  As a result, the output current Ipls of the pulse power supply 6 becomes zero, and the transition to the steady operation state is completed (period (8)). At this time, the pulse power supply 6 stands by in the gate shift state as shown in FIG.

  The above description has shown the case where the current Ic of the superconducting coil 5 is sharply increased. However, when the current Ic of the superconducting coil 5 is sharply decreased, the state is similarly changed to the pulse operation state (FIG. 8). This period (5)) is made possible by the steady power supply 1 and the pulse power supply 6 outputting a negative voltage in the operation state.

  From the above description, according to the present invention, when a steady current is passed through the superconducting coil 5, the superconducting coil 5 is energized via the switch 3 with only the steady power supply 1. When the current is changed sharply, the steady power supply 1 and the pulse power supply 6 output voltages, and the output voltages of both the power supplies 1 and 6 can be added together to apply a high voltage to the superconducting coil 5. An increase in size can be prevented, and an inexpensive power supply system can be provided.

In addition, according to the present invention, a power supply system that can be operated by connecting a pulse power supply 6 in series to a stationary power supply 1 with a simple component configuration and that can change the current supplied to the superconducting coil 5 sharply is provided. Has the effect of becoming possible.

  In addition, according to the present invention, since the switch 3 can be opened with zero current, it is possible to reliably prevent an arc from being generated at the time of opening, and to prevent contact loss of the switch 3. As a result, the life of the switch 3 can be extended.

  Moreover, in the said Example, although the switch which does not have an electric current interruption capability was used for the switch 3, and demonstrated the small and cheap structure which connects and operates a power supply in series, this invention is described in the said switch. Instead, it is a matter of course that a circuit breaker having a current interruption capability or a switch may be used.

In addition to the above, it goes without saying that the switch 3 can be configured using a semiconductor switch element such as a thyristor or IGBT.

  Further, in this embodiment, the entire power supply system A is configured as shown in FIG. 1, but as shown in FIG. 9, the switch 3 and the DC current transformer 4 connected in series are connected in parallel to the pulse power supply 6, Even if the positive electrode side of the pulse power source 6 is connected to the negative electrode side of the steady power source 1 and the negative electrode side of the pulse power source 6 is connected to the superconducting coil 5, the same effect as the power source system A shown in FIG. .

  In this embodiment, the case where the pulse power source 6 controls the current flowing through the switch 3 to zero when the switch 3 is opened has been described. However, the control of the pulse power source 6 outputs a predetermined positive voltage. Thus, the present invention is established even when voltage control is performed.

  It is possible to provide a power supply system capable of continuously allowing a constant current to flow through the superconducting coil and abruptly changing the current passing through the superconducting coil as necessary.

It is a circuit diagram of the power supply system of this invention. In the circuit diagram, it is an explanatory diagram when the pulse power supply is in a gate shift state. It is explanatory drawing which shows the state from which the electric current which flows into a switch became zero because the said pulse power supply controlled the electric current which flows into a switch. It is explanatory drawing which shows the state which opened the switch. It is explanatory drawing which shows the state in which the pulse power supply is outputting predetermined | prescribed negative voltage (-5 [V]) in order to close the said switch. It is explanatory drawing which shows the state which closed the said switch. It is explanatory drawing which shows the state from which the output current of the said pulse power supply became zero. In the said circuit diagram, it is explanatory drawing which shows the waveform of the output voltage and output current of each component. It is a circuit diagram of the power supply system which concerns on the other Example of this invention. This is a power supply circuit for a conventional fusion device.

Explanation of symbols

1 Low voltage continuous rated power supply (steady power supply)
3 Switch 4 DC current transformer 5 Superconducting coil 6 High voltage short-time rated power supply (pulse power supply)
A Power supply system as a whole

Claims (1)

A high-voltage short-circuit rated first power supply and a high-voltage short-time rated second power supply are connected in series, and a continuous-rated switch is connected in parallel with the output of the second power supply. In a capacity direct current power supply system, when shifting from a state in which the superconducting coil is energized only by the first power source to a state in which current is energized by the first power source and the second power source, The output voltage is changed to control so that the current flowing through the switch becomes zero, the switch is opened when the current flowing through the switch is a predetermined value or less, and the superconducting coil When the first power source and the second power source are switched to a state where only the first power source is energized, the second power source outputs a negative voltage and then opens and closes the open / close state. The current path flowing through the second power source is closed to the switch by closing the switch. Superconducting coil power supply system and controls as obtain.

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