JPS5845265B2 - Surge energy absorption element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a surge energy absorbing element, and more particularly to a surge energy absorbing element suitable for preventing electrode wear due to dielectric breakdown occurring between electrodes of a large accelerator used in a nuclear fusion device, etc. .

Figure 1 is a circuit diagram for explaining a conventionally used surge energy absorbing element.
is an accelerator, which has an acceleration electrode 11 and a ground electrode 12, and each acceleration and ground electrode 11 and 12 are connected to a power source 2.
High voltage power is supplied by the

By the way, since a high voltage is applied to the accelerating electrode 11 and the grounding electrode 12, the insulation often breaks down and the energy stored in the stray capacitance 3 is released to the accelerating electrode 11 and the grounding electrode 12.

For this reason, the accelerating electrode 11 and the grounding electrode 12 are significantly worn out, and the accelerator 1 may eventually become unusable.

The surge energy absorbing element 4 is used to prevent the acceleration electrode 11 and the earth electrode 12 from being worn out due to dielectric breakdown.

The operation of this surge energy absorbing element 4 will be explained using the equivalent circuit shown in FIG.

Here, the gap corresponding to the accelerating electrode 11 and the grounding electrode 12 shown in FIG. .

Note that 8 is a stray capacity which corresponds to the total of the stray capacity 3 shown in FIG.

When the insulation breaks down in the gap 5 in the case shown in FIG. 2, the energy stored in the stray capacitance 8 flows into the gap 5 as a surge current.

However, since the surge current is blocked by the inductance 6, the surge current flows through the resistance component I.

Here, most of the surge energy associated with the surge current is consumed as Joule heat that increases the resistance component 7Vc, and the energy consumed in the gap 5 can be significantly reduced. Wear is prevented.

By the way, the conventional surge energy absorbing element 4 has a third
As shown in the figure, a coil in which a thin plate 9 made of a ferromagnetic material such as a silicon steel plate or permalloy is wound many times is used as the core, and the magnetic energy accumulated in the thin plate 9 causes the inductance component shown in Fig. 2. 6, the surge energy is absorbed by the Joule loss caused by the eddy current 10 flowing through the ferromagnetic material of the thin plate 9.

However, the conventional surge energy absorbing element 4
Since energy is absorbed using eddy currents generated in ferromagnetic materials, the resistance component has nonlinear characteristics, making it difficult to design the design value and resistance component of the button.

The present invention has been developed in view of the above points, and an object thereof is to provide a surge energy absorbing element whose resistance component can be easily designed.

In the present invention, a core of a ferromagnetic material installed to interlink with a conductor through which a surge current flows is made of ferrite, a resistor is provided coaxially with the ferrite core, and the resistor is interlinked with the ferrite core. By arranging it in such a way, it served as a distant relative of the intended purpose.

Hereinafter, the present invention will be described in detail based on embodiments of the drawings.

An embodiment of the present invention is shown in FIGS. 4 and 5.

The core 101 is made of a cylindrical ferrite whose eddy current is almost negligible, and is separated and insulated from each other by an insulating spacer 109.

Furthermore, a resistor 10 is coaxially connected to this ferrite core 101.
6 is installed outside the ferrite core 101, and this resistor 106 is coaxially connected to the ferrite core 101 by a metal conductor 108, and is arranged so as to interlink with the ferrite core 101.

Note that the conductor 103 is a single conductor representing a large number of conductors interlinked with the ferrite core 101.
A surge current flows through the conductor 103.

With this configuration of this embodiment, the conductor 10
When a surge current flows through the resistor 3, the surge current is induced in the resistor 106 by the ferrite core 101.

At this time, since the resistor 106 is coaxial with the ferrite core 101, the inductance of the resistor 106 can be reduced to a negligible level. Therefore, it is easy to design a resistor for absorbing surge energy, and the stray capacitance can be reduced. It becomes possible to select the optimum resistance value taking into consideration the electrode structure of the accelerator.

Therefore, surge energy can be efficiently absorbed by the resistor 106.

Other embodiments of the present invention are shown in FIGS. 6 and 7.

In the embodiment shown in FIGS. 4 and 5, the resistor 106 used in the embodiment shown in FIGS.
It is placed inside 1.

Even with such a configuration, the effect is exactly the same as that of the above-mentioned embodiment, and in particular, the configuration of this embodiment has the following effects:
This is effective when there is sufficient space between the conductor 103 and the ferrite core 101, and there is an advantage that the installation area can be further reduced.

FIG. 8 shows still another embodiment of the present invention.

In the embodiment shown in FIGS. 4 and 5, a uniform resistor 102 having a coaxial structure is used instead of the resistor 106 and metal conductor 108 arranged coaxially. According to the resistor 106 shown in FIGS. 4 and 5, the inductance can be further reduced, and further effects can be expected.

The core used in the past was expensive because it was wound several hundred times with a thin plate of approximately 100 μm in order to improve the frequency characteristics. Since the body is used, the production of the core,
It also has the effect of being inexpensive.

By the way, the reciprocating conductors in this embodiment are used, for example, to supply current to the filament of an accelerator, and for an acceleration voltage of 100 kVK, the potential of each conductor with respect to the ground is about 100 kV-1-10 V, 100 kV-10 V. and Natte kr), for dielectric breakdown of 100 KV, it can be treated as one conductor, and the equivalent circuit shown in FIG. 2 is obtained, so there is no problem.

According to the surge energy absorbing element of the present invention described above, the core of the ferromagnetic material interlinked with the conductor through which the surge current flows is made of ferrite, and the resistor is provided coaxially with the ferrite core. The resistor is installed so as to interlink with the ferrite core, so when a surge current flows through the conductor, a surge current is induced in the resistor, but the resistor is coaxial with the ferrite core. Therefore, the inductance of the resistor can be made negligibly small, and a surge energy absorbing element whose resistance component can be easily designed can be obtained.

[Brief explanation of the drawings] Figure 1 is a circuit diagram for explaining a conventionally used surge energy absorbing element, Figure 2 is an equivalent circuit diagram of the circuit in Figure 1, and Figure 3 is a circuit diagram for explaining a conventional surge energy absorbing element. FIG. 4 is a partially sectional front view of an energy absorbing element, FIG. 4 is a partially sectional front view of an embodiment of the surge energy absorbing element of the present invention, and FIG. FIG. 6 is a partially sectional front view of another embodiment of the present invention, FIG. 7 is a partially sectional side view of FIG. 6, and FIG. 8 is a partially sectional side view of another embodiment of the present invention. FIG. 7 is a partially cross-sectional front view of still another embodiment. DESCRIPTION OF SYMBOLS 1... Accelerator, 2... Power supply, 3, 8... Stray capacitance, 4... Surge energy absorption element, 5... Gap, 6... Inductance, 7... Resistance, 9...・・・
Ferromagnetic material, 10... Eddy current, 11... -jJ electrode, 12... Earth electrode, 101... Ferrite core, 102.106... Resistor, 103... Conductor, 1
07.108...Metal conductor, 109...Insulating spacer.

Claims (1)

[Claims] 1. A surge energy absorbing element having a core made of ferromagnetic material installed interlinked with a conductor through which a surge current flows, the core made of ferrite, and a resistor coaxially connected to the ferrite core. A surge energy absorbing element characterized in that the resistor is installed so as to be interlinked with the ferrite core.