JP2009033014A - Superconducting coil power supply control device and superconducting equipment - Google Patents

Abstract

When quench detecting means is used for a large superconducting coil having an inductance of 1H or more, erroneous detection of quenching when exciting or demagnetizing the superconducting coil is prevented.
A DC power supply 12 for supplying a current to a superconducting coil 13 and a standard voltage generator 11 having a program P for controlling the power supply by applying a standard voltage corresponding to the current set every predetermined time to the DC power supply. The program includes an excitation period for boosting the standard voltage to a predetermined voltage, a boost start period for exponentially increasing the standard voltage with respect to time, and a boost intermediate period for increasing the standard voltage linearly with respect to time. The standard voltage generator is divided into boosting end periods that gradually increase so as to have saturation characteristics with respect to time, and the standard voltage generator sets the standard voltage set for each of the divided periods according to the program at regular intervals. It is characterized by being fed to a DC power source.
[Selection] Figure 2

Description

  The present invention relates to a power supply control device for a superconducting coil and a superconducting device equipped with the power supply control device. Specifically, the present invention aims to remove and reduce noise detected by a quench detector.

Conventionally, in a superconducting device equipped with a superconducting magnet, current is passed from a power source to the superconducting coil to excite the superconducting coil. At this time, a voltage of L · (dI / dt) is generated at both ends of the superconducting coil. . (L is the inductance of the superconducting coil, I is the current flowing through the superconducting coil, t is time, and dI / dt is the rate of change of current over time)
In particular, in the case of a superconducting coil having a large inductance L of 1H (Henry) or more, if the current flowing through the superconducting coil is suddenly increased or decreased, a high pulse voltage is temporarily generated in the voltage generated at both ends of the superconducting coil. To do.

Superconducting equipment usually includes quench detection means for detecting quenching of a superconducting coil, and the applicant of the present application disclosed in Japanese Patent Laid-Open No. 2006-319139 (Patent Document 1) is a superconductivity equipped with this kind of quench detection means. Equipment is provided.
As shown in FIG. 4, the superconducting device 1 provided in Patent Document 1 includes a power source 2, a superconducting coil 3 supplied with power from the power source 2, and a quench detector that detects a precursor phenomenon of quenching of the superconducting coil 3. 4 and a power supply control circuit 5 that is connected to the quench detector 4 and adjusts the coil current.
The quench detector 4 employs a neutral point system in which the midpoint of the superconducting coil 3 is taken with a voltage tap and a balance signal is taken with the voltage tap of the variable resistor 6 connected in parallel with the superconducting coil 3. In the neutral point method, the voltage of the inductance component of the superconducting coil is eliminated and the voltage of the component after the hand is detected. When a quench precursor phenomenon occurs in the superconducting coil 3 and the resistance value of the superconducting coil 3 increases, the bridge circuit composed of the superconducting coil 3 and the variable resistor 6 is unbalanced, and a differential voltage is generated. The quench of the superconducting coil 3 is detected by detecting this differential voltage.

JP 2006-319139 A

However, when a superconducting coil having an inductance L as large as 1H (Henry) is used, if the current supplied to the superconducting coil is suddenly increased or decreased, a large pulse voltage is generated at both ends of the superconducting coil as described above. Arise. As a result, the balance of the bridge circuit is lost, and large pulse voltages V1 to V4 are temporarily generated in the differential voltage as shown in FIG. 5, and the quench detector 4 easily misidentifies this pulse voltage as the occurrence of quench, There is room for improvement in this regard.
The pulse voltage shown in FIG. 5 is obtained when a voltage is applied to a superconducting coil having an inductance L of 37H, and the pulse voltage V1 is a pulse voltage generated at the start of excitation when the power source starts applying voltage to the superconducting coil. The pulse voltage V2 is a pulse voltage that is generated when the voltage applied by the power source is increased to reach a predetermined voltage and the increase of the voltage is stopped. The pulse voltage V3 is a pulse voltage generated at the start of demagnetization to reduce the applied voltage from the state where the power supply is applying a predetermined voltage to the superconducting coil, and the pulse voltage V4 is a demagnetization that makes the applied voltage to the superconducting coil zero. This is the pulse voltage generated at the end. As described above, according to the test conducted by the present inventor, at the start of voltage supply to the superconducting coil, at the transition from the transformation period to the period for keeping the voltage constant (voltage holding period), from the voltage holding period to the transformation period. It has been confirmed that a large pulse voltage is generated when the voltage supply is stopped at the time of transition.

  In order to remove such a pulse voltage, a continuous noise cut filter may be attached to the quench detector. However, with the noise cut filter, it is difficult to remove the large pulse voltages V1 to V4 that are temporarily generated during the excitation / demagnetization of the superconducting coil as described above, and it is necessary for quench detection by the noise cut filter. In some cases, the voltage of the resistance component of the superconducting coil is removed.

  The present invention has been made in view of the above problems, and it is an object of the present invention to prevent erroneous detection of quench of quench detection means connected to a superconducting coil when exciting and demagnetizing a superconducting coil having an inductance as large as 1H or more. It is said.

In order to solve the problem,
A direct current power source for supplying current to the superconducting coil;
A standard voltage generator having a program connected to the DC power source and having a program for controlling a current to the superconducting coil by applying a standard voltage set every predetermined time to the DC power source,
The program is
An excitation period for boosting the standard voltage to a predetermined voltage, a boost start period for exponentially increasing the standard voltage with respect to time, and a boost intermediate period for linearly increasing the standard voltage with respect to time; The standard voltage is divided into boosting end periods that gradually increase so as to have saturation characteristics with respect to time,
According to the program, the standard voltage generator provides a superconducting coil power supply control device that applies a standard voltage set for each of the divided periods to the DC power supply for each predetermined time. ing.

  In the superconducting coil power supply control apparatus of the present invention having the above-described configuration, a standard voltage generator is connected to a DC power supply for supplying power to the superconducting coil, and a voltage applied from the standard voltage generator to the DC power supply is set by the program. The standard voltage is defined in units of a certain time, and this controls the amount of current supplied from the DC power source to the superconducting coil.

Specifically, as described above, in the excitation period in which the current value supplied from the DC power source to the superconducting coil is continuously increased to a predetermined current value, the three periods of the boost start period, the boost intermediate period, and the boost end period The standard voltage generator sets the standard voltage at regular intervals in the program.
As described above, in the boost start period, the voltage increase is increased exponentially by increasing the rate of voltage increase over time from the start of the boost start period, and the voltage increases at the end of the boost start period. Is the same as the rate of voltage increase at the start of the boosting intermediate period.
In the step-up intermediate period, the applied voltage is increased linearly with a constant rate of voltage increase over time.
That is, at the start of the increase of the standard voltage applied to the DC power supply of the standard voltage generator (at the time of rising), the voltage is not increased linearly, but after the voltage has been gradually increased by providing a boost start period The voltage is increased linearly during the boosting intermediate period.
In addition, when boosting the applied voltage to the predetermined voltage, the voltage increase ratio is not to linearly reach the predetermined voltage but to have a saturation characteristic over time by providing a boosting end period. By decreasing the voltage, the voltage is increased more slowly than in the boosting intermediate period.
After the end of the boosting period, that is, after the end of the excitation period, a constant predetermined voltage is applied to the power source.

Compared with the case where the voltage is increased linearly to a predetermined voltage during excitation and the voltage is applied suddenly, the standard voltage generator of the power supply control device of the present invention has a boost start period and a boost end period, When the voltage rises or reaches a predetermined voltage, the voltage is increased more slowly than the intermediate step-up period, so that the change in the standard voltage can be reduced, and the change in the current flowing from the DC power supply to the superconducting coil is also reduced. For this reason, it is possible to prevent a pulse voltage from being temporarily generated in the superconducting coil at the start and end of the current increase when increasing the current flowing from the power source to the superconducting coil.
In particular, in the case of a large superconducting coil having an inductance L of 1H (Henry) or more, a pulse voltage is likely to be generated temporarily at the start and end of an increase in current flowing from the power source to the superconducting coil, and therefore the voltage control device of the present invention is suitable. Used for.
Further, if the rate of voltage increase is always moderated during the excitation period, it takes too much time to reach the predetermined voltage. However, in the standard voltage generator of the power supply control device, the boosting of the excitation period Since the rate of increase of the voltage is increased during the intermediate period, the time required to reach the predetermined voltage can be shortened, and the voltage can be efficiently applied to the power supply.

In the excitation period in which the applied voltage is boosted from zero to a predetermined voltage, the standard voltage in the boost start period is increased at regular intervals by a fourth to sixth exponential function, and the standard voltage in the boost end period is the predetermined voltage. It is preferable to increase at regular intervals with a fourth to sixth exponential function so that the curve is saturated toward the voltage.
The reason why the fourth-order to sixth-order exponential function is increasing or decreasing is that the applied voltage in the boost start period is increased by an exponential function smaller than the fourth order, or the applied voltage in the boost end period is less than the fourth order. When it is decreased by an exponential function, the rate of increase in voltage applied to the DC power source by the standard voltage generator is reduced, and the time until the voltage reaches a predetermined voltage is increased.
On the other hand, when the applied voltage during the boost start period is increased by an exponential function larger than the sixth order, or when the applied voltage during the boost end period is decreased by an exponential function smaller than the sixth order, the standard voltage generator This is because the rate of increase in the voltage applied to the abrupt becomes abrupt, and a pulse voltage may be temporarily generated in the voltage generated at both ends of the superconducting coil.

  A demagnetization period in which the standard voltage is stepped down from a predetermined voltage to zero or a required voltage, a step-down start period in which the standard voltage is decreased so as to have saturation characteristics with respect to time, and the standard voltage is linear with respect to time. It is preferable that the voltage is set at regular intervals by dividing into a step-down intermediate period in which the voltage is decreased and a step-down end period in which the standard voltage is decreased exponentially with respect to time.

Similarly to the above-described excitation, the standard voltage generator sets the standard voltage to be decreased by a certain time unit at the time of demagnetization, and the demagnetization period includes a step-down start period, a step-down intermediate period, and a step-down end period. The standard voltage is set in three periods.
In this way, in the demagnetization period, as in the excitation period, the standard voltage generator has a step-down start period and step-down end period to reduce the voltage more slowly than the step-down intermediate period. It is possible to prevent a pulse voltage from being temporarily generated in the superconducting coil at the start and end of the current reduction when reducing the current to be supplied to the coil.
In the standard voltage generator of the power supply control device, since the rate of voltage reduction is increased during the step-down intermediate period of the demagnetization period, the time required for step-down can be shortened, and the power supply can be efficiently Can be applied with a voltage.

The control of the current value to the superconducting coil performed by the program-controlled standard voltage generator has a large voltage fluctuation range at the time of excitation in which the excitation period is increased from zero to a predetermined voltage and at the time of demagnetization to be decreased to zero. It works particularly effectively.
In superconducting coil operation, the amount of change in current when starting or stopping the superconducting coil is larger than the amount of current change for coil control during operation of the superconducting coil. The pulse voltage is most likely to be generated in the superconducting coil when stopped.
For this reason, by using the power supply control device of the present invention at the start or stop of the operation of the superconducting coil, it is possible to effectively prevent a pulse voltage from being generated in the superconducting coil.

In the standard voltage generator, it is preferable to set the standard voltage in a range of 0.05 to 2 seconds as a fixed time unit.
The standard voltage is applied to the DC power source as a digital signal in a certain time unit, and the certain time (sampling period) of the digital signal is set to 0.05 to 2 seconds.
If the fixed time is longer than 2 seconds, it is difficult to continuously change the voltage value when the rate of increase or decrease of the standard voltage applied to the DC power supply is large. If it is small, a high-speed computing unit is required for the standard voltage generator. More preferably, the fixed time is set to 0.1 sec.
Further, it is preferable that the standard voltage generator applies the standard voltage to the power supply at regular intervals even when the magnetic field is held after the excitation period and before the demagnetization period.

The present invention also provides a superconducting device provided with the power supply control device.
The superconducting device is provided with a bridge circuit in which a superconducting coil connected to the power supply control device and a variable resistor are connected in parallel,
A quench detector connected to the superconducting coil of the bridge circuit and a variable resistor, measuring a differential voltage of the bridge circuit and detecting quenching of the superconducting coil when the differential voltage exceeds a predetermined threshold; A breaker that separates the DC power supply of the power supply control device and the superconducting coil when a quench is detected is provided.

The superconducting device includes a quench detector for a superconducting coil, and detects a quench based on a differential voltage of the bridge circuit.
Conventionally, if the current flowing through the superconducting coil is changed suddenly, a pulse voltage is generated in the superconducting coil and a pulse voltage is also generated in the differential voltage, and the quench detector may mistakenly recognize the pulse voltage as the occurrence of quenching. However, since the pulse voltage is prevented from being generated in the superconducting coil by using the power supply control device of the present invention, the quench detector is prevented from being mistaken for the occurrence of the quench by the pulse voltage. Can do.

  As described above, according to the power supply control device for a superconducting coil of the present invention, the standard voltage generator provides a boost start period and a boost end period at the time of excitation, and when the applied voltage rises or reaches a predetermined voltage, Since the voltage is increased more slowly than the period, the change in voltage can be reduced, and as a result, the change in current supplied from the DC power supply to the superconducting coil can be reduced. For this reason, it is possible to prevent a pulse voltage from being temporarily generated in the superconducting coil at the start and end of the increase in increasing the current flowing from the power source to the superconducting coil.

  Further, according to the superconducting device of the present invention provided with the power supply control device, since the pulse voltage is prevented from being generated in the superconducting coil, the quench detector is prevented from being mistaken for the occurrence of the quench by the pulse voltage. can do.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 3 show an embodiment of the present invention.
A superconducting device 10 having a superconducting magnet according to this embodiment is connected to a superconducting coil 13 via a breaker 20 and an output terminal 21 with a DC power source (hereinafter abbreviated as a power source) 12.
The DC power supply 12 is connected to a standard voltage generator 11 for power supply control and constitutes a power supply control device 30. The standard voltage generator 11 may be incorporated in the DC power source 12 in advance.

The standard voltage generator 11 applies a standard voltage to the power source 12 in order to control the current flowing from the power source 12 to the superconducting coil 13, and is a program in which the standard voltage to be applied to the power source 12 is set in a certain time unit. P is provided.
According to the program P, the standard voltage generator 11 applies a standard voltage to the power source 12, and the power source 12 supplies a current having a required current value to the superconducting coil 13 according to the standard voltage.

  The superconducting coil 13 is a coil having an inductance L of 37H formed by winding an oxide superconducting wire (B @ 2223, Bi2212, or YBCO). Although not shown, the superconducting coil 13 is cooled to a superconducting temperature by a refrigerant made of liquid nitrogen. ing.

A bridge circuit 15 is configured by connecting a variable resistor 14 in parallel to the superconducting coil 13, and a quench detector 16 is connected to the superconducting coil 13 and the variable resistor 14 of the bridge circuit 15. The midpoint of the superconducting coil 13 is taken with a voltage tap, a balance signal is taken with the voltage tap of the variable resistor 14 for detecting the voltage of the superconducting coil 13, and the balance signal is inputted to the quench detector 16.
When quenching occurs in the superconducting coil 13 and the resistance value of the superconducting coil 13 increases, the balance of the bridge circuit 15 is lost, and the resulting differential voltage is input to the quench detector 16. In the quench detector 16, the threshold value of the differential voltage for detecting that the quench has occurred in the superconducting coil 13 is set to 0.2 V, and the superconducting coil 13 is quenched when a differential voltage of 0.2 V or more is detected. Detect as.

When quenching of the superconducting coil 13 is detected by the quench detector 16, the breaker 20 is dropped via the cutoff circuit 18 in accordance with a command from the relay sequence 17 to shut off the power supply 12 and the superconducting coil 13.
Further, a protective resistor 22 and a diode 23 are connected in parallel to the superconducting coil 13. When the breaker 20 is dropped and the power supply 12 and the superconducting coil 13 are shut off, the energy accumulated in the superconducting coil 13 is converted into a current as a diode 23. It is consumed by the protective resistance 22 in the direction regulated by the current.

The standard voltage generator 11 controls the power supply 12 so that a voltage detected as a quench by the quench detector 16 is not generated by fluctuations in the current value supplied from the power supply 12 to the superconducting coil 13, and a pulse voltage (so-called “so-called”). Noise) is prevented.
Specifically, the standard voltage is digitally applied from the standard voltage generator 11 to the power source 12 every predetermined time, and the fixed time is 0.05 to 2 seconds. In this embodiment, it is set to 0.1 second.

Hereinafter, the standard voltage that is program-controlled in the standard voltage generator 11 will be described in detail.
When the program P of the standard voltage generator 11 applies a voltage to the power supply 12, as shown in FIG. 2, the voltage value is changed from zero to a predetermined voltage Vtop until time t3 from the start of supply at time s = 0. The excitation period T1 during which the voltage is continuously boosted is used.
The excitation period T1 includes a boost start period T1-1 in which the applied voltage increases exponentially with respect to time, a boost intermediate period T1-2 in which the applied voltage increases linearly with respect to time, and the application It is divided into a boosting end period T1-3 in which the voltage is increased so as to have a saturation characteristic with respect to time.
In FIG. 2, time s = t1 is the end of the boost start period T1-1, that is, the start of the boost intermediate period T1-2, and time is the end of the boost intermediate period T1-2, that is, the start of the boost end period T1-3. s = t2 and the end of the boosting end period T1-3 is time s = t3.

Further, when the standard voltage generator 11 stops the standard voltage applied to the power supply 12, the demagnetization period in which the applied voltage is continuously reduced from the predetermined voltage Vtop to zero during the predetermined period from time s = 4 to t7. T3. The demagnetization period T3 includes a step-down start period T3-1 in which the applied voltage is decreased so as to have saturation characteristics with respect to time, and a step-down intermediate period T3-2 in which the applied voltage is decreased linearly with respect to time. And the step-down termination period T3-3 in which the applied voltage decreases exponentially with respect to time.
In FIG. 2, time s = t5 at the end of the step-down start period T3-1, that is, the start of the step-down intermediate period T3-2, and time at the end of the step-down intermediate period T3-2, that is, the start of the step-down end period T3-3. s = t6, and the end of the step-down termination period T3-3 is time s = t7.
Further, the voltage holding period T2 is the magnetic field holding time after the excitation period T1 and before the demagnetization period T3.

Specifically, the voltage y (s) applied to the power supply 12 by the standard voltage generator 11 in the boost start period T1-1 is expressed by Expression (1). Note that s is an elapsed time from the start of power supply, and a and b are constants.

Next, the voltage y (s) applied to the power supply 12 by the standard voltage generator 11 during the boosting intermediate period T1-2 is expressed by Expression (2). The time s = t1 = Tc is the start of the boosting intermediate period T1-2, that is, the end of the boosting start period T1-1, and Vcv indicates the rate of voltage increase in the boosting intermediate period T1-2. The rate of voltage increase is constant.

Further, the voltage y (s) applied to the power source 12 by the standard voltage generator 11 during the boosting end period T1-3 is expressed by Expression (3). The time t3 is the end of the boosting end period T1-3, and Vtop is applied by the standard voltage generator 11 to the power supply 12 when the magnetic field is held after the excitation period T1 and before the demagnetization period T3 (voltage holding period T2). Is a predetermined voltage.

Next, the constants of Equations (1) to (3) described above are specifically determined, and the time s when the standard voltage generator 11 continuously applies a voltage from zero to a predetermined voltage to the power source 12 is determined. Find the voltage.
First, constants a and b in Equation (1) are determined so as to satisfy the following conditions.
(1) The increase rate of the current of the power supply 12 is set to 0.002 A / sec for 1 minute.
(2) The current value that the power supply 12 passes through the superconducting coil in 3 minutes is set to 36A.
Here, since 300A corresponds to 10V, when a and b are calculated by substituting the above conditions into the equation (1), a = 6.417 × 10 ⁻¹⁴ and b = 5.192.
Thus, the applied voltage in the boosting start period T1-1 is expressed by an approximately fifth order function.

Next, a voltage increase rate Vcv in the boosting intermediate period T1-2 is obtained. Assuming that the rate of increase in current with respect to the time of the boosting intermediate period T1-2 is 0.16 A / sec, 300 A corresponds to 10 V, so Vcv = 0.16 × 10/300 = 5.333 × 10 ^−3. .

式（４）＝Ｖｃｖから昇圧開始期間Ｔ１−１の終了時、即ち、昇圧中間期間Ｔ１−２の開始時である時間ｔ１＝Ｔｃを求めると、Ｔｃ＝２７１．８５９ｓｅｃとなる。 At time t1 = Tc, the rate of increase in voltage at the end of the boost start period T1-1 is equal to the rate of increase in voltage Vcv in the boost intermediate period T1-2.
The rate of increase in voltage at the end of the boost start period T1-1 is expressed by the differentiation of equation (1), and is expressed by equation (4).

When the time t1 = Tc at the end of the boosting start period T1-1, that is, the start of the boosting intermediate period T1-2 is obtained from the equation (4) = Vcv, Tc = 271.859 sec.

式（５）にＶｔｏｐ、Ｔｃを代入すると、Ｖｌｎ＝６．５９１Ｖとなる。
このとき、昇圧中間期間Ｔ１−２の経過時間Ｔｌｎ（＝時間ｔ２−ｔ１）は
Ｔｌｎ＝Ｖｌｎ／Ｖｃｖ＝１．２３６×１０^３ｓｅｃとなる。 Assuming that Isc = 214.5A is a predetermined current that the power supply 12 passes through the superconducting coil 13 during the voltage holding period T2, the predetermined voltage Vtop = Isc · 10V / 300A = 7.15V applied to the superconducting coil is obtained.
Further, a voltage Vln that rises during the boosting intermediate period T1-2 is obtained. In the present embodiment, the time width of the boost start period T1-1 is defined as time Tc, and the time width of the boost end period T1-3, that is, time t3-t2, is defined as time Tc.
At this time, the voltage Vln is obtained by Expression (5).

Substituting Vtop and Tc into equation (5) gives Vln = 6.591V.
At this time, the elapsed time Tln (= time t2-t1) of the boosting intermediate period T1-2 is Tln = Vln / Vcv = 1.236 × 10 ³ sec.

  That is, as shown in FIG. 2, the voltage applied to the power source 12 by the standard voltage generator 11 is expressed as a boosting start period T1-1 from time s = 0 to t1 (= Tc) in the excitation period T1 (1) ), From time t1 to t2 (= Tc + Tln) becomes the voltage shown in equation (2), and from time t2 to t3 (= 2 · Tc + Tln) becomes the voltage shown in equation (3).

Thus, the predetermined voltage Vtop is applied to the power supply 12 using the time of the excitation period T1.
Here, it is assumed that the predetermined voltage Vtop is continuously applied to the power source 12 for a predetermined period T2 (voltage holding period T2) from the end of the boosting end period T1-3, and in this embodiment, the voltage holding period T2 is Told = 3. Trying for a minute.
The voltage holding period T2 is a period during which the superconducting coil 13 is operated (used), and the length of the voltage holding period T2 is not limited to 3 minutes, but is determined by the use of the superconducting coil 13 or the like.

Next, a case where the power source 12 stops the current flowing to the superconducting coil 13, that is, a case where the voltage applied to the power source 12 by the standard voltage generator 11 is zero will be described.
At this time, the standard voltage generator 11 continuously decreases the applied voltage from the predetermined voltage Vtop to zero in the demagnetization period T3.
In the demagnetization period T3, the values of the constants a and b are the same as those in the excitation period T1, and the voltage that changes the time t6-t5 of the step-down intermediate period T3-2 to Tln and the step-down intermediate period T3-2. Vln, the rate of voltage decrease in the step-down intermediate period T3-2 is Vcv, times t5-t4 and t7-t6 of the step-down start period T3-1 and step-down end period T3-3 are Tc, and are the same as the excitation period T1. .

The voltage y (s) in the step-down start period T3-1 is expressed by Expression (6). The time t4 is the start time of the step-down start period T3-1, and t4 = Tc · 2 + Tln + Told · 60 sec.

The voltage y (s) in the step-down intermediate period T3-2 is expressed by Expression (7). Here, time t5 = t4 + Tc = Tc · 3 + Tln + Told · 60 sec.

The voltage y (s) in the step-down termination period T3-3 is expressed by Expression (8). Here, time t7 = Tc · 4 + Tln · 2 + Told · 60 sec.

In the present embodiment, the values of constants a, b, Tln, Vln, Vcv, Tc and the like are the same as those in the excitation period T1 even in the demagnetization period T3, but each value is different from that in the excitation period T1. The time width of the period and the rate of voltage decrease may be changed.
In the present embodiment, a = 6.417 × 10 ⁻¹⁴ , but a is 2 × 10 ⁻¹⁵ to 4 × 10 ⁻¹¹ , more preferably 2.509 × 10 ^{−15 to} 3.643 ×. It may be ^10-11 .
In the present embodiment, b = 5.192, but b may be 4 to 6, more preferably 4.114 to 5.74.

As described above, when the voltage applied to the power supply 12 by the standard voltage generator 11 of the power supply control device 30 is controlled in units of time as described above, the voltage boost start period T1-1 and the voltage drop start period T3-1 during excitation. In addition, the voltages in the boosting end period T1-3 and the step-down finishing period T3-3 can be changed gradually.
At this time, the pulse voltages V1 to V4 appearing in the differential voltage of the bridge circuit 15 become 0.1V as shown in FIG. 3, and become 1/10 of the pulse voltage of about 1V shown in FIG.
As described above, the temporary pulse voltages V1 to V4 generated regardless of the quenching are made extremely small.
Moreover, by using the power supply control device 30, the pulse voltage appearing in the differential voltage of the bridge circuit 15 can be reduced, and the pulse voltage V1 to V4 is more than the threshold value 0.2V for detecting the quench set by the quench detector 16. Therefore, it is possible to prevent erroneous quench detection.

  In the present embodiment, the standard voltage is boosted from zero to a predetermined voltage during the excitation period, and the standard voltage is stepped down from the predetermined voltage to zero during the demagnetization period, but the standard voltage is not zero during the excitation period. The voltage may be boosted from the value to another predetermined voltage. Further, during the demagnetization period, the standard voltage may be stepped down from a predetermined voltage to another predetermined voltage value. That is, when it is necessary to increase or decrease the current that the power source passes through the superconducting coil during the voltage holding period T2 during which the superconducting coil is in operation, the standard voltage generator is standardized to the power source using the program provided in the standard voltage generator. A voltage may be applied.

  The above-described embodiments are exemplifications in all points, and are not limited to these embodiments. The scope of the present invention is indicated by the scope of claims, and all modifications within the scope equivalent to the scope of claims are made. Is included.

  The superconducting equipment provided with the power supply control device of the present invention is used as a power storage device (SMES) including a large superconducting coil having a superconducting coil inductance of 1H (Henry) or more, and a high magnetic field magnet in general.

It is a circuit diagram of the superconducting device of the embodiment of the present invention. It is drawing which shows the change of the power supply voltage controlled by the power supply control apparatus. It is drawing which shows the difference voltage of a bridge circuit. It is drawing which shows a prior art example. It is drawing which shows the conventional problem.

Explanation of symbols

10 Superconducting equipment 11 Standard voltage generator 12 DC power supply 13 Superconducting coil 14 Variable resistor 15 Bridge circuit 16 Quench detector T1 Excitation period T1-1 Boosting start period T1-2 Boosting intermediate period T1-3 Boosting end period T2 Voltage holding period T3 Demagnetization period T3-1 Step-down start period T3-2 Step-down intermediate period T3-3 Step-down end period

Claims (6)

A direct current power source for supplying current to the superconducting coil;
A standard voltage generator having a program connected to the DC power source and having a program for controlling a current to the superconducting coil by applying a standard voltage set every predetermined time to the DC power source,
The program is
An excitation period for boosting the standard voltage to a predetermined voltage, a boost start period for exponentially increasing the standard voltage with respect to time, and a boost intermediate period for linearly increasing the standard voltage with respect to time; The standard voltage is divided into boosting end periods that gradually increase so as to have saturation characteristics with respect to time,
The superconducting coil power supply control device, wherein the standard voltage generator applies a standard voltage set for each of the divided periods to the DC power supply at the predetermined time according to the program.   In the excitation period in which the applied voltage is boosted from zero to a predetermined voltage, the standard voltage in the boost start period is increased at regular intervals by a fourth to sixth exponential function, and the standard voltage in the boost end period is the predetermined voltage. The superconducting coil power supply control device according to claim 1, wherein the power supply control device is increased by a fourth to sixth exponential function at regular intervals so that the curve is saturated toward the voltage.   A demagnetization period in which the standard voltage is stepped down from a predetermined voltage to zero or a required voltage, a step-down start period in which the standard voltage is decreased so as to have saturation characteristics with respect to time, and the standard voltage is linear with respect to time. The voltage is set at regular intervals by dividing into a step-down intermediate period in which the voltage is decreased and a step-down end period in which the standard voltage is decreased exponentially with respect to time. Power supply control device for superconducting coils. The fixed time is 0.05 to 2 seconds, and a standard voltage is set in the fixed time unit,
The superconductivity according to any one of claims 1 to 3, wherein the standard voltage generator applies the standard voltage to the power supply at regular intervals even when the magnetic field is held after the excitation period and before the demagnetization period. Coil power supply control device. A bridge circuit in which a superconducting coil connected to the power supply control device according to any one of claims 1 to 4 and a variable resistor are connected in parallel is provided.
A quench detector connected to the superconducting coil of the bridge circuit and a variable resistor, measuring a differential voltage of the bridge circuit and detecting quenching of the superconducting coil when the differential voltage exceeds a predetermined threshold; A superconducting device comprising a breaker for separating the DC power supply of the power supply control device and the superconducting coil when a quench is detected.   The superconducting device according to claim 5, wherein an inductance of the superconducting coil is 1H or more.

Images