JPH0521945Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a surge sensor for detecting surge current.

[Conventional technology]

A conventionally known device of this kind is to form a broadband current transformer by passing the primary conductor through a ring-shaped iron core made of a ferrite core and equipped with a secondary coil, and applying the output voltage of the secondary coil to a light-emitting diode to emit light. Some devices extract the light through an optical fiber, apply it to a light/voltage converter, and convert it into an electrical signal.

[Problem that the invention attempts to solve]

However, this configuration uses a secondary coil wound around an iron core to insulate it from the primary conductor to which high voltage is applied. As a result, the current transformer itself became large and heavy, and the entire structure, including the primary conductor, was housed in an upper tank, which was then insulated and supported by a porcelain tube, which had the disadvantage of being expensive, large, and heavy.

[Means for solving problems]

In order to solve the above-mentioned drawbacks, the present invention has a cylindrical primary conductor with a large number of small holes to form a coiled path, and when current flows through this, it flows through the coiled path and causes a voltage drop due to inductance. to occur. In this way, when a surge current flows, the current is appropriately limited and applied to the light emitting diode, and the light from the light emitting diode when the surge current enters is applied to the light/voltage conversion mechanism through an optical fiber and extracted as an electrical signal. .

〔Example〕

Figure 1a is a circuit diagram showing an embodiment of the present invention, Figure 1b is a circuit diagram showing an embodiment of the present invention.
is also an outline diagram of the primary conductor. The primary conductor 1 is made of a circular tubular conductor, and a part thereof has many small holes 1.
a1 is provided to form a coil-shaped path, an inductance portion 1a formed to have an inductance of a predetermined value is provided, and the voltage of the inductance portion 1a is taken out from terminals 1b and 1c.

Next, the terminal voltage is current-limited to a predetermined current value through a current-limiting circuit 2 configured by combining resistors, for example, and applied to light-emitting diodes 3A and 3B, and the light is transmitted to an optical fiber cable 5 including optical fibers 4A and 4B. It is applied to the optical/voltage converter 6 through a transmission line consisting of:

Inductance portion 1a provided in primary conductor 1
Since the resistance value r is extremely small and can be ignored, and the inductance L is also small, even if a commercial frequency current flows through the primary conductor, the terminal voltage is small and the light emitting diodes 3A and 3B do not emit light.

When a surge current flows through the primary conductor due to a direct lightning strike, etc., the inductance L of the inductance portion 1a is small, but due to the high frequency component of the surge current, the inductance L is proportional to the product of the inductance L, frequency, and current value between terminals 1b and 1c. A large high frequency voltage is generated, which is current limited to a predetermined current value by the current limiting circuit 2 and applied to the light emitting diodes 3A and 3B, causing them to emit light.

Next, this light is applied to a light/voltage converter 6 through an optical fiber cable 5 made up of optical fibers 4A and 4B, and is converted into an electrical signal to operate, for example, a display (not shown) to indicate that a surge current has flowed. can be done.

In this way, in the present invention, the sensor 7 for detecting a surge is formed by the inductance portion 1a of the primary conductor, the current limiting circuit 2, and the light emitting diodes 3A, 3B.
is configured. Therefore, like the conventional example above,
There is no need to use a secondary coil wrapped around an iron core to insulate it from the primary conductor to which high voltage is applied.
The sensor 7 is extremely small and lightweight.

Therefore, as a supporting means, as shown in FIG. 2, a sensor 7 is provided in the middle of the outside line lead-in part, and is suspended from a frame 9 by a side suspension insulator 8 or the like.
As shown in FIG. 1a, the signal can be connected through an optical fiber cable 5 and converted into an electrical signal by adding it to a light/voltage converter 6 provided at an arbitrary location.

Here, as the inductance portion 1a of the primary conductor, for example, the conductor may be wound to form a coil shape. However, when the conductor is wound in this way, it cannot maintain the coil shape by itself. It is not possible to do so, and it must be fixed by adding strong insulators, etc. In this regard, according to the present invention, the shape of the inductance portion can be maintained by the primary conductor itself, and a predetermined inductance value can be maintained.

In addition, in FIG. 1a, it has been explained that the inductance portion 1a of the primary conductor 1 in FIG. A coil-shaped path is formed, and various paths that naturally pass through the gaps between the small holes 1a1 and do not contribute to the formation of the coil shape are formed.

That is, the illustrated series circuit of the inductance L and the resistance r includes a coil-shaped path and the small hole 1a1.
It is composed of a parallel circuit with a large number of paths that are not related to the formation of the coiled path passing through the gap between It is shown as a circuit.

Further, in the above embodiment, the primary conductor 1 is shaped like a circular tube, but the primary conductor 1 is not necessarily shaped like a circular tube, and may be formed of a tubular conductor.

[Effect of idea]

As explained above, the surge sensor according to the present invention is small and lightweight, can be held with a simple support structure, and can be connected to any location via an optical fiber cable from the surge sensor and added to a light/voltage converter. , electrical signals can be extracted.

[Brief explanation of the drawing]

Fig. 1a is a circuit diagram showing the configuration of an embodiment of the surge sensor, Fig. 1b is an outline drawing showing an embodiment of the primary conductor with an added inductance portion, and Fig. 2 is an explanatory diagram showing an embodiment of the surge sensor support means. It is. 1...Primary conductor, 1a...Inductance part, 1a1...Small hole, 2...Current limiting circuit, 3A, 3
B... Light emitting diode, 4a, 4B... Optical fiber, 5... Optical fiber cable, 6... Optical/
Voltage converter, 7...Surge sensor.

Claims (1)

[Scope of utility model registration request] A primary conductor made of a tubular conductor with a number of small holes formed in a part of the tube wall to form a coil-shaped path and having an inductance of a predetermined value to form an inductance part, and an output voltage of the inductance part being applied, means for current limiting to a predetermined current value, a light emitting diode to which an output voltage of the current limiting means is applied, a light/voltage converter provided at a predetermined position, and light from the light emitting diode to the light/voltage converter. A surge sensor characterized by comprising a transmission path made of an optical fiber.