JP2000208233A - Lightning arrester - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize cost reduction and miniaturization of a line installing unit as a result of making it possible to extract voltage proportional to the voltage of a line from a terminal connected with an electrode, and install a high voltage detection element such as a condenser for high voltage or a transformer in devices. SOLUTION: In this lightning arrester, which houses a dielectric element of nonlinear voltage characteristic in a cylindrical case, a high voltage side electrode 4 is connected at one end of it, a grounded electrode 6 is connected at the other end, a porcelain tube 2 or insulating resin is used for the case, and zinc oxide element is used as the dielectric element, which is divided into a high voltage dielectric element 4 and a low voltage dielectric element 6, then a middle electrode 5 for high voltage detection is inserted into the cleavage between them. By installing a terminal 9 connected with the electrode 5 on the side of the case, the voltage of a line with which the lightning arrester is connected is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lightning arrester, and more particularly, to a lightning arrester used for a device installed on a transmission line or a distribution line to detect a voltage.

[0002]

2. Description of the Related Art Conventionally, a lightning arrester has been mounted inside a track or a line-installed device to prevent lightning damage to power transmission lines and distribution lines. As an example, there is a switch with a built-in lightning arrester described in Japanese Utility Model Application Laid-Open No. 2-134631. FIG. 3 shows the structure of a conventional lightning arrester. In this surge arrester, a high-voltage side electrode 1 is fitted and held at an upper end of an insulator tube 2, and a columnar dielectric element 14 made of zinc oxide is mounted at a lower end of the high-pressure side electrode 1 via a spring 3. The lower end of the dielectric element 14 is in contact with and supported by the ground electrode 7. The ground electrode 7 is fitted and held at the lower end of the insulator tube 2. on the other hand,
In order to detect a line voltage in a line installation device, it is generally necessary to incorporate a voltage detection element such as a high-voltage capacitor or a transformer in the device. 4 and 5 show a conventional switch 11.
1 shows an example in which a lightning arrester 12 and a voltage detection element 13 are installed.

[0003]

As described above, the line-installed equipment having both the lightning arrester and the voltage detecting element is more expensive and larger in size than the equipment having only the lightning arrester built therein.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a first aspect of the present invention is to accommodate a dielectric element made of zinc oxide having a voltage non-linear characteristic in a substantially cylindrical case and having one end thereof. A high voltage side electrode is connected to the other end, and a ground side electrode is connected to the other end. In the lightning arrester, the dielectric element is divided into two and a voltage detecting electrode is inserted into a divided portion thereof, and the voltage detecting electrode is connected to the voltage detecting electrode. The terminal is provided on the side of the case. Here, the case can be formed as an insulator tube or integrally formed as an insulating resin.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of an embodiment of the present invention, and FIG. 2 is an explanatory diagram schematically showing an essential part of FIG. 1 taken out. In the figure, reference numeral 1 denotes a high-voltage side electrode, which is fitted to the upper end of a porcelain tube 2 which is a case. At the lower end of the high voltage side electrode 1, a columnar high voltage side dielectric element 4 made of zinc oxide is mounted via a spring 3. As shown in FIG. 2, a ground-side dielectric element 6 is in contact with a lower end of the dielectric element 4 via an intermediate electrode 5 for voltage detection. The lower end of the dielectric element 6 is in contact with and supported by the ground electrode 7. The ground electrode 7 is fitted and held at the lower end of the insulator tube 2.

The intermediate electrode 5 is connected to a terminal 9 provided on a side surface of the insulator tube 2 by a connection line 8. Note that electrode portions are formed on the upper and lower surfaces of the dielectric elements 4 and 6 by screen printing. In this surge arrester, the high voltage side electrode 1 is connected to a line, and the ground side electrode 7 is connected to a ground line. Thereby, a voltage value proportional to the voltage of the line is detected from the terminal 9. Note that as another embodiment,
Although not shown, it is also possible to form a structure in which each component is sealed in the insulating resin by integrally molding the portion of the insulator tube 2 in FIG. 1 as an insulating resin such as an epoxy resin.

Here, the dielectric elements 4, 6 on both the high voltage side and the low voltage side employ a zinc oxide element having excellent voltage non-linear characteristics and an extremely small current flowing even when a voltage is applied as described above. No series gap connected. Also, since the zinc oxide element has a high dielectric constant (ε _s = 1000 to 2000), the high-voltage side electrode 1, the high-voltage side dielectric element 4, and the intermediate electrode 5 The distribution line voltage is shared by the side capacitor and the low voltage side capacitor formed by the intermediate electrode 5, the low voltage side dielectric element 6, and the ground side electrode 7. The voltage shared by the low voltage side capacitor is (thickness of low voltage side element 6) / (thickness of high voltage side element 4 + thickness of low voltage side element 6) because high voltage side dielectric element 4 and low voltage side dielectric element 6 have the same diameter. Thickness), and the sharing voltage can be set very easily.

The high-voltage side electrode 1 is connected to a charging section in the outer case connected to the distribution line, the intermediate electrode 5 is connected to a controller (not shown), and the ground-side electrode 7 is connected to the outer case and the outer case grounding terminal. , And detects and converts the voltage shared by the low-voltage side capacitor to perform steady state distribution line voltage management.
If a lightning surge or the like voltage enters the switch from the distribution line, the zinc oxide element has a remarkably low impedance with respect to the overvoltage, and in this state, the impedance from the intermediate electrode 5 to the controller (not shown) becomes high and almost the current is reduced. Current flows through the high-voltage side electrode 1, the high-voltage side element 4, the low-voltage side element 6, the outer case grounding terminal, and the path of the ground, thereby limiting the overvoltage and protecting the switch and the distribution line.

Further, since the high-voltage side electrode 1, high-voltage side element 4, intermediate electrode 5, low-voltage side element 6, and ground-side electrode 7 are connected in series in the hollow portion of the cylindrical insulator tube 2, the switching contacts and the like are provided. It can be used as a support insulator that can withstand strong mechanical force. Similarly, if resin is integrally molded with epoxy resin, etc.,
It also prevents moisture and the like and facilitates handling during assembly. In this way, the lightning arrester can be used as a support insulator of a charging unit, having functions of a light load power supply voltage such as a voltage detection capacitor, a signal transmission coupling capacitor, and a controller drive. When installing these lightning arresters on equipment,
For example, it can be built in an insulating cylindrical base of a power distribution device.

Therefore, according to the lightning arrester of the present invention, the lightning arrester having both the lightning protection function and the voltage detecting function is provided in the outer case of the power distribution equipment such as the switch, and the lightning arrester is further provided with a charging unit in the outer case. Can be integrated into an insulating table that supports and insulates, and devices and elements that have been installed for each individual function can be collected. In addition, the number of components, the number of components, and other related components are also reduced, so that the outer diameter of the device can be reduced, thereby contributing to cost reduction of the power distribution device.

[0011]

As described above, according to the present invention, by inserting an electrode for voltage detection in the middle of a dielectric element, a voltage value proportional to the line voltage is taken out from a terminal connected to this electrode. This makes it unnecessary to install a voltage detecting element such as a high-voltage capacitor or a transformer in the device. As a result, cost reduction and downsizing of the track installation equipment are realized.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram schematically showing a main part of FIG. 1;

FIG. 3 is a sectional view showing a conventional example.

FIG. 4 is a cross-sectional view showing an example of attachment to a conventional device.

FIG. 5 is a cross-sectional view showing an example of attachment to a conventional device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 High voltage side electrode 2 Insulator tube 3 Spring 4 High voltage side dielectric element 5 Intermediate electrode 6 Ground side dielectric element 7 Ground side electrode 8 Connection line 9 Terminal

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Takahiro Otsuka 1-7-1, Yurakucho, Chiyoda-ku, Tokyo F-term within Toko Electric Co., Ltd. 5E034 CA09 EA07 EB01 EB04 EB05 EC01

Claims (4)

[Claims] 1. A lightning arrester having a substantially cylindrical case containing a dielectric element having voltage non-linear characteristics and having one end connected to a high voltage side electrode and the other end connected to a ground side electrode. And a voltage detecting electrode is inserted into the divided portion, and a terminal connected to the voltage detecting electrode is provided on a side surface of the case. 2. The lightning arrester according to claim 1, wherein the dielectric element is a zinc oxide element. 3. The lightning arrester according to claim 1, wherein the case is an insulator. 4. The lightning arrester according to claim 1, wherein the case is integrally formed as an insulating resin.