JPS5949556B2 - How to excite a large capacity coil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for exciting a large-capacity coil, particularly a large-capacity coil having a large inductance, a small resistance, and a large time constant.

Large-capacity coils include toroidal coils and current transformer coils for nuclear fusion devices, and electromagnetic coils for particle accelerators.

In such a large capacity coil, its time constant is a considerable amount of time because its inductance is large and its resistance is small.

For this reason, when attempting to excite these large-capacity coils, the rise time of the current increases in proportion to the time constant.

On the other hand, taking the toroidal coil of a nuclear fusion device as an example, the toroidal coil of a nuclear fusion device is pulse-excited by applying a large current for several tens of seconds and then stopping the excitation for several minutes.

In such a pulse-excited toroidal coil, the time for the current to rise during excitation is comparable to or longer than the time the rated current is flowing, and the current is consumed until the rated current is reached. There are problems such as an increase in electric power and an increase in the temperature of the toroidal coil.

FIG. 1 shows an example of a conventional method of exciting a large capacity coil.

That is, the resistance of the coil is R8, and the rated current that you want to flow through it is ■.

When closed, the coil has a rated voltage E as the excitation voltage e.

=Ro×■o is given from the beginning.

However, since this coil has a large inductance and a small resistance R8, the time constant τ of the coil is large, and therefore the rise time t8 of the excitation current i is also large, and the excitation voltage e is the rated voltage E.

The rated voltage I required for the coil, regardless of whether it is applied for a considerable period of time.

does not flow.

This rise time t3 is unnecessary for coil excitation, and the longer the rise time t, the more heat generated in the coil increases, not only heating the coil but also excitation power P consumed during this time. will be wasted.

Now considering the case of excitation of a toroidal coil of a nuclear fusion device, the time constant τ is about 35 seconds, and therefore the rise time t is about 60 seconds.

On the other hand, the time required to operate the toroidal coil at its rated current, or the rated current■.

The time required for the flow to flow is about 15 seconds, and it can be seen that the rise time t is very long compared to this rated operating time (18-1).

For this purpose, an excitation method as shown in FIG. 2 can be considered.

This excitation method first uses the rated voltage E. An excitation voltage e that is greater than, for example, the rated voltage E.

The coil is excited by applying a voltage e twice that of , and the exciting current i is the rated current ■.

At the point in time, the excitation voltage e is set to the rated voltage Eo and rated operation is performed.

This makes it possible to significantly reduce the rise time t compared to the excitation method shown in FIG.

Also, when demagnetizing the coil from the rated operating state, -2E
The demagnetization time is shortened by applying a voltage of o to the coil.

However, in this excitation method, the excitation power p required for excitation is the rated power P.

For this purpose, it is necessary to increase the size of the power supply equipment, which also has the drawback of increasing the power cost.

The present invention has been made in view of the above points, and an object of the present invention is to provide an excitation method that can reduce the rise time of a large-capacity coil with a large time constant and reduce the maximum power consumption. According to the present invention, when exciting a large-capacity coil used in a nuclear fusion device or particle accelerator, which has a large inductance, a small resistance, and a large time constant, the large-capacity coil is Apply an excitation voltage larger than the rated voltage to the large-capacity coil, and when the excitation current increases and the excitation power reaches a predetermined power, the excitation voltage is sequentially decreased as the excitation current increases so that the excitation power does not exceed the predetermined power. By doing so, the object of the present invention can be achieved.

The present invention will be explained below with reference to the drawings.

FIG. 3 shows a method of exciting a large-capacity coil according to an embodiment of the present invention.

This excitation method first uses the rated voltage E.

An excitation voltage e that is greater than, for example, the rated voltage E.

The coil is excited by applying an excitation voltage e twice that of , and the excitation current i increases to 7, and the excitation power p becomes the rated power P.

At the time tm, the excitation power p becomes the rated power P.

The excitation voltage e is sequentially decreased so that the excitation voltage e reaches the rated voltage E at time t5 when the excitation current i reaches the rated current I.

Make it so that By adopting this excitation method, the maximum power used is the rated voltage P.

Moreover, the excitation rise time t is the maximum excitation power equal to the rated power P.

This can be done faster compared to conventional binding methods.

As a result, the power supply equipment has a rated power of P.

Any type of coil that can supply a high capacity is sufficient, and since the rise time t becomes faster, the amount of heat generated by the large capacity coil can be reduced, and as a result, the large capacity coil can also be configured in a smaller size. .

Also, when a large capacity coil is demagnetized from its rated operating state, -E is applied to the large capacity coil.

voltage is given.

This allows the large capacity coil to be quickly demagnetized.

FIG. 4 shows an example of an excitation device for using the excitation method of the present invention.

In the figure, power is supplied to a power transmission line 1 through a disconnector 2, a breaker 3, and a transformer 4 to a thyristor bridge 5.

The DC power that has been full-wave rectified by this Sirisk bridge 5 is given to the large capacity coil 6.

As described above, this large-capacity coil 6 is, for example, a toroidal coil of a nuclear fusion device, and has a large inductance and a small resistance.

Therefore, the time constant τ of the large capacity coil 6 is large.

A current detector 7 is provided in series in a circuit connecting the thyristor bridge 5 and the large-capacity coil 6, and voltage detectors 8 are provided at both ends of the large-capacity coil 6.

The outputs of this current detector 7 and voltage detector 8 are given to a power limiter 9.

This power limiter 9 prevents the excitation power of the large capacity coil 6, that is, the product of the excitation current and excitation voltage detected by the current detector 7 and voltage detector 8, from exceeding a predetermined value. It operates to provide signals to gate control device 10 to generate gate signals to control each thyristor.

To explain the excitation operation in the device configured as described above, in the initial stage of excitation, a gate signal is applied to the gate of each thyristor of the thyristor bridge 5 by the gate control device 10, and the thyristor is brought into a conductive state. The rated voltage E of the large capacity coil 6 is applied to the capacity coil 6.

For example, a voltage twice the rated voltage is applied.

When the excitation current increases and the excitation power reaches the rated power, the power limiter 9 detects this state and sends a signal to the gate control device 10 to control the gate of the thyristor bridge 5 to reduce the voltage. let

This control is performed sequentially as the excitation current of the large capacity coil 6 increases.

Rated current ■ for large capacity coil 6.

When flows, the voltage is the rated voltage E. It is driven as such.

In the above embodiments, the initial excitation voltage is the rated voltage E.

The initial excitation voltage is preferably selected to be about 1.5 to 3 times the rated voltage, which is higher than the rated voltage.

In addition, when the current increases and the excitation power reaches the rated power as a predetermined power, the voltage is sequentially decreased. However, the predetermined power is not limited to the rated power mentioned above, but can also be applied to the vicinity of the rated power. Even if the power is slightly larger than the rated power, it can be made similar.

As explained above, the present invention applies an excitation voltage higher than the rated voltage of the large-capacity coil to the large-capacity coil at the initial stage of excitation, and when the excitation current increases and the excitation power reaches a predetermined power near the rated power, the excitation is applied to the large-capacity coil. Since the excitation voltage is sequentially decreased as the excitation current increases so that the electric power does not exceed the predetermined power, the rise time during excitation of a large-capacity coil can be reduced, and the maximum power consumption can be reduced. Therefore, it is possible to provide a method for exciting a large-capacity coil that can be used.

[Brief explanation of drawings]

Figures 1 and 2 are waveform diagrams of excitation voltage, excitation current, and excitation power showing a conventional method for excitation of a large-capacity coil, and Figure 3 is an excitation of a large-capacity coil showing an embodiment of the present invention. FIG. 4 is a waveform diagram of excitation voltage, excitation current, and excitation power showing the method, and is a circuit diagram suitable for implementing the method of excitation of a large-capacity coil according to the present invention. Explanation of symbols, e...Excitation voltage, i...
Excitation current, p...Excitation power, 5...Sirisk bridge, 6...Large capacity coil, 7.
...Current detection device, 8...Voltage detection device, 9...Power limiter-110...
Gate control device.

Claims (1)

[Claims] 1. In the excitation method for large-capacity coils used in nuclear fusion devices and particle accelerators that have large inductance, small resistance, and a large time constant, the excitation voltage is higher than the rated voltage of the large-capacity coil during the initial excitation period. When the excitation current applied to the capacitor coil increases and the excitation power reaches a predetermined power near the rated power, the excitation voltage is sequentially decreased in accordance with the increase in the excitation current so that the excitation power does not exceed the predetermined power. A method of exciting a large capacity coil characterized by: