JP2007329174A - Current-voltage non-linear resistor, and lightening arrester - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a current-voltage non-linear resistor which can achieve miniaturization of an overcurrent protector such as a lightening arrester and a surge absorber, has high resistance value and excellent thermal stability, and is excellent in non-linear resistant characteristics and life characteristics. <P>SOLUTION: The resistor is configured of a sintered body principally containing zinc oxide (ZnO), containing as sub-components; bismuth (Bi), cobalt (Co), manganese (Mn), antimony (Sb) and nickel (Ni) which are converted into oxide expressions of 0.3-1.0 mol% Bi<SB>2</SB>O<SB>3</SB>, 0.3-1.5 mol% Co<SB>2</SB>O<SB>3</SB>, 0.1-2 mol% MnO, 0.5-2.5 mol% Sb<SB>2</SB>O<SB>3</SB>and 0.5-3 mol% NiO respectively, and having a relation of relative ratios of bismuth to antimony and of manganese to cobalt which is converted into an oxide expression represented by 0.15<Bi<SB>2</SB>O<SB>3</SB>/Sb<SB>2</SB>O<SB>3</SB><1.0 and 0.3<MnO/Co<SB>2</SB>O<SB>3</SB><3.5. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a current-voltage nonlinear resistor mainly composed of zinc oxide used in a lightning arrester, a surge absorber, etc., and in particular, a current-voltage obtained by improving the component composition of subcomponents contained in the main component. It relates to a non-linear resistor.

  In general, in a power system or an electronic device circuit, an overvoltage protection device such as a lightning arrester or a surge absorber is used to remove an overvoltage superimposed on a normal voltage and protect the power system or the electronic device. In this overvoltage protection device, a current-voltage nonlinear resistor is frequently used. This current-voltage non-linear resistor has a characteristic that it shows almost an insulation characteristic at a normal voltage and has a low resistance value when an overvoltage is applied.

This current-voltage nonlinear resistor is composed of zinc oxide (ZnO) as a main component and Bi ₂ O ₃ , Co ₂ O ₃ , MnO, Sb ₂ O ₃ , and NiO added as subcomponents thereto. It is used as a raw material (see Patent Document 1). These raw materials are sufficiently mixed together with water and a binder, then granulated by a spray dryer or the like, molded and sintered to constitute a sintered body. Thereafter, an insulating material for preventing creeping flash is applied to the side surface of the sintered body and heat-treated to form a side insulating layer. And the current-voltage nonlinear resistor is manufactured by grind | polishing the both end surfaces of a sintered compact, and attaching an electrode.

  By the way, there is a demand for an increase in capacity of substations accompanying an increase in power demand in recent years and a reduction in size of substation equipment accompanying the installation of underground substations. Current-voltage non-linear resistors mainly composed of zinc oxide are used in lightning arresters due to their excellent non-linear resistance characteristics, but if the resistance value of the current-voltage non-linear resistors is improved, The number of current-voltage non-linear resistors to be stacked can be reduced, and the size and size of the lightning arrester can be reduced. Therefore, an improvement in the resistance value of the current-voltage nonlinear resistor is increasingly required.

For example, according to the technique disclosed in Patent Document 2, the content of subcomponents such as Bi ₂ O ₃ , Co ₂ O ₃ , MnO, Sb ₂ O ₃ , NiO is limited, and ZnO is the main component. By limiting the crystal phase of Bi ₂ O ₃ contained in the sintered body, a current-voltage nonlinear resistor having a high resistance value and excellent nonlinear resistance characteristics can be provided.

In addition, according to the technique disclosed in Patent Document 3, Patent Document 4, or Patent Document 5, zinc oxide is a main component, and Bi ₂ O ₃ , Co ₂ O ₃ , MnO, Sb ₂ O _{3, and the} like are added. By adding a rare earth oxide to the current-voltage nonlinear resistor, a current-voltage nonlinear resistor having a high resistance value and excellent characteristics can be provided.
Japanese Patent Publication No. 4-25681 JP 2001-307909 A Japanese Patent No. 2933881 Japanese Patent No. 2940486 Japanese Patent No. 3165410

  However, at present, the characteristics required for the current-voltage non-linear resistor are becoming stricter, and the above-described conventional technology cannot satisfy the required characteristics.

  Specifically, when the resistance of the current-voltage non-linear resistor is increased, the amount of surge energy absorbed increases, so that when the surge energy is absorbed, the heat generation temperature due to Joule heating of the current-voltage non-linear resistor increases. . Current-voltage nonlinear resistors have the characteristic that the resistance value decreases when the temperature rises.Therefore, if the temperature becomes too high, the leakage current increases, and thermal runaway occurs due to the commercial frequency current after absorbing the surge energy. Since the non-linear resistor is destroyed, it has been impossible to apply a non-linear resistor having a sufficiently high resistance or an element having a small diameter.

  Recently, in order to reduce the size and cost of the lightning arrester, it is required to apply a non-linear resistor having a diameter as small as possible. However, in the conventional technology as described above, there is a limit to the miniaturization. there were.

  The present invention has been proposed in view of the above points, and its purpose is to provide a high-resistance current-voltage non-linear resistor and a small-diameter non-linear resistor capable of reducing the size of a lightning arrester. In addition to being excellent in non-linear resistance characteristics and life characteristics, the current-voltage non-linearity that reduces the decrease in resistance value when the temperature of the current-voltage non-linear resistance rises, that is, excellent in thermal stability. The object is to provide a resistor and a sufficiently miniaturized lightning arrester.

The current-voltage nonlinear resistor of the present invention has zinc oxide (ZnO) as a main component and bismuth (Bi), cobalt (Co), manganese (Mn), antimony (Sb), and nickel (Ni) as subcomponents. _Bi 2 _O 3 are each _oxide, Co ₂ O _{3, MnO,} in terms of _{Sb 2 O 3, NiO, 0.3~1.0mol} % of _Bi 2 _{O 3,} the _Co 2 _{O 3} 0.3 ~1.5mol%, 0.1~2mol% of MnO, _Sb 2 _{O 3} of 0.5 to 2.5 mol%, the NiO containing 0.5 to 3 mol%, and bismuth and antimony and manganese and cobalt relative ratio, respectively, in terms of _{oxide, 0.15 <Bi 2 O 3 /} Sb 2 O 3 <1.0,0.3 < be a sintered body which is a _MnO / _Co 2 O 3 <3.5 It is characterized by.

Of the above components, Bi ₂ O ₃ is a component that exists at the grain boundaries of ZnO, which is the main component of the sintered body, and exhibits nonlinear resistance characteristics, and has the effect of promoting grain growth of ZnO crystals. is there. Sb ₂ O ₃ forms spinel (Zn ₇ b ₂ O ₁₂ ) particles together with ZnO to control and homogenize the grain growth of the ZnO particles during sintering, thereby improving the non-linear resistance characteristics; There is an effect of suppressing grain growth of ZnO crystal. Co ₂ O _3, NiO, MnO is a solid solution mainly in the spinel grains, the effect of improving the non-linear resistance characteristics. These subcomponents synergistically affect the thermal stability of the nonlinear resistor.

  In the present invention, a current-voltage non-linear resistor excellent in non-linear resistance characteristics and thermal stability can be obtained due to each phenomenon caused by being in the component composition range. As a result, according to the present invention, it is possible to obtain a current-voltage nonlinear resistor having a high resistance value and excellent thermal stability, and excellent in non-linear resistance characteristics and life characteristics, such as a lightning arrester and a surge absorber. Miniaturization of the overvoltage protection device can be realized.

(1) First Embodiment Hereinafter, a first embodiment of the present invention will be described with reference to FIG.

In the first embodiment, the component content of the current-voltage nonlinear resistor finally obtained is bismuth (Bi), cobalt (Co), manganese ( Mn), antimony (Sb), and nickel (Ni) are converted into oxides Bi ₂ O ₃ , Co ₂ O ₃ , MnO, Sb ₂ O ₃ , and NiO, respectively. A material obtained by weighing a predetermined amount of Bi ₂ O ₃ , Co ₂ O ₃ , MnO, Sb ₂ O ₃ , and NiO so as to have a value of 51 is used as a raw material.

This raw material was mixed with water and organic binders in a mixing apparatus to prepare uniform slurries. Here, it is added 0.003 mol% of aluminum as aluminum hydroxide _{(Al (NO 3) 3 ·} 9H 2 O) aqueous solution for all samples.

  Next, each obtained slurry was spray-granulated with a spray dryer to prepare granulated powder having a particle size of about 100 μm. The obtained granulated powder was put into a mold and pressurized, formed into a disc having a diameter of 125 mm and a thickness of 30 mm, and the molded body was heated to 500 ° C. to remove the added organic binders. Firing was performed at 1100 ° C. for 2 hours.

  Next, as shown in FIG. 1, an inorganic insulating material was applied to the side surface of the sintered body 1 and heat-treated to form a side surface insulating layer 2. Furthermore, after polishing both the upper and lower end surfaces of the sintered body provided with the side insulating layer, the electrode 3 was prepared on the polished surface of the sintered body 1 by thermal spraying to produce a current-voltage nonlinear resistor.

With respect to the various current-voltage non-linear resistors produced, the voltage (V _{10 kA} ) when an 8 × 20 μs impulse current of 10 kA was passed was measured, and the ratio (V _{10 kA} / V _{1 mA} ) to the operation start voltage (V _{1 mA} ) was measured. ) Was evaluated as a nonlinear coefficient. The smaller the value of this nonlinearity coefficient, the better the nonlinear resistance characteristic.

  Moreover, as evaluation of thermal stability, resistance leakage current was measured and evaluated when an AC voltage of 90% of the operation start voltage was applied in a 200 ° C. thermostat. That is, the smaller the high-temperature leakage current at 200 ° C., the better the thermal stability.

  In addition, the element from which a composition differs was measured 10p at each composition, and the average value was made into the value of the composition. The measurement results are shown in Table 1.

Sample numbers marked with * in Table 1 have compositions outside the scope of the present invention, and are samples prepared for comparison.

As is clear from the results shown in Table 1, the sample numbers marked with * as a comparative example do not satisfy the following excellent current-voltage nonlinear resistor conditions.
And non-linearity _{(V 10kA / V 1mA) <} 1.50
・ High temperature leakage current (200 ℃) <15mA

  In the present invention, the composition component range is defined as described above. However, if this range is exceeded, a sufficiently high non-linear resistor cannot be obtained, or the thermal stability or non-linearity of the non-linear resistor is not obtained. This is because the resistance characteristics are deteriorated.

  On the other hand, by defining the composition range within the range of the present invention, it is shown that the three characteristics of the operation start voltage, nonlinearity, and high-temperature leakage current are excellent. Therefore, according to the present embodiment, a current-voltage nonlinear resistor having excellent thermal stability, nonlinear resistance characteristics, and a high operation start voltage can be obtained.

(2) Second Embodiment Corresponding to Claim 2 A second embodiment will be described with reference to Table 2. In the second embodiment, an oxide of yttrium (Y) is added to the raw material of the first embodiment in a range of 0.01 to 1.0 mol% in terms of Y ₂ O ₃ . Is.

In the present embodiment, bismuth (Bi), cobalt (Co), manganese (Mn), antimony are finally added as auxiliary components to ZnO as the main component content of the current-voltage nonlinear resistor. (Sb), nickel (Ni), and yttrium (Y) are converted to Bi ₂ O ₃ , Co ₂ O ₃ , MnO, Sb ₂ O ₃ , NiO, and Y ₂ O ₃ which are oxides, respectively, and Bi ₂ O ₃ 0.5 mol%, Co ₂ O ₃ , MnO 1.0 mol%, Sb ₂ O ₃ 1.5 mol%, NiO 2 mol%, Y ₂ O ₃ 0.005 to 1.5 mol%, Then, each was weighed and added, and a current-voltage nonlinear resistor was produced by the method shown in the first embodiment.

For these current-voltage nonlinear resistors, the nonlinear coefficient and thermal stability were measured by the method shown in the first embodiment, and the results are shown in Table 2. In Table 2, * indicates a sample that is outside the scope of the present invention.

  Note that in this embodiment, an oxide of yttrium (Y) is used as the rare earth oxide, but other rare earth elements such as europium (Eu), erbium (Er), thulium (Tm), and gadolinium are used. It has been confirmed that even if an oxide of (Gd), dysprodium (Dy), holmium (Ho), or ytterbium (Yb) is used, the same effect as that of the yttrium (Y) oxide can be obtained.

Therefore, at least one rare earth selected from yttrium (Y), europium (Eu), erbium (Er), thulium (Tm), gadolinium (Gd), dysprodium (Dy), holmium (Ho), and ytterbium (Yb). By including 0.01 to 1.0 mol% of the oxide of element R in terms of R ₂ O ₃ , it is possible to provide a non-linear resistor excellent in non-linear resistance characteristics even when the resistance is increased.

Namely, rare earth elements to form a _{ZnO, Sb} 2 O 3, etc. _Bi 2 _{O 3} composite oxide, the effect of suppressing the grain growth of ZnO crystals. Here, if the amount of additive of Sb ₂ O ₃ , Co ₂ O ₃ , NiO, MnO is increased in order to increase the resistance of the current-voltage nonlinear resistor, the temperature dependence of the resistance value increases. Thermal stability will decrease. Here, when the resistance is increased by adding a rare earth element having a high resistance effect, the amount of additive of Sb ₂ O ₃ , Co ₂ O ₃ , NiO, MnO can be reduced, and the current-voltage nonlinear resistor Can improve the thermal stability of

(3) Third Embodiment Corresponding to Claim 3 A third embodiment will be described with reference to Table 3. In the third embodiment, 0.001 to 0.015 mol% of aluminum is added to the raw material of the first embodiment in terms of Al ³⁺ .

In the present embodiment, bismuth (Bi), cobalt (Co), manganese (Mn), antimony are finally added as auxiliary components to ZnO as the main component content of the current-voltage nonlinear resistor. (Sb) and nickel (Ni) are converted to Bi ₂ O ₃ , Co ₂ O ₃ , MnO, Sb ₂ O ₃ , and NiO, which are oxides, respectively, and Bi ₂ O ₃ is 0.5 mol%, Co ₂ O. _3, MnO, respectively, 1.0mol%, _Sb 2 _{O 3} of 1.5 mol%, 2 mol% of NiO, further, in terms Al a _{(NO 3) 3 · 9H 2} O in ^{Al 3+} .00005 to 0 A current-voltage nonlinear resistor was manufactured by the method shown in the first embodiment after weighing to 0.02 mol% and adding each.

  With respect to these current-voltage nonlinear resistors, the nonlinear coefficient was measured by the method shown in the first embodiment, and the nonlinear resistance characteristics were evaluated. The nonlinearity coefficient is shown in Table 3 below. In Table 3, * indicates a sample that is outside the scope of the present invention.

As is apparent from Table 3, it is clear that the non-linear resistance characteristic can be improved by setting the Al content to 0.001 to 0.015 mol%. That is, Al ³⁺ is dissolved in ZnO particles and has the effect of improving the non-linear resistance characteristics by reducing the electrical resistance of the ZnO particles. For this reason, it is possible to have excellent non-linear resistance characteristics by adding Al ^{3+ in an amount} of 0.001 mol% or more. Moreover, when it adds more than 0.015 mol%, a non-linear resistance characteristic will be deteriorated conversely.

In the present embodiment, the Al-containing effect is shown only for the basic composition, but it has been confirmed that the same effect can be obtained within the basic composition range of claim 1 or 2.

(4) Fourth Embodiment: Corresponding to Claim 4 The fourth embodiment will be described with reference to Table 4. In the fourth embodiment, 0.005 to 0.05 wt% is added to the raw material of the first embodiment by converting silver into Ag ₂ O.

In the fourth embodiment, the subcomponent content of the current-voltage nonlinear resistor is ZnS as the main component, and finally bismuth (Bi), cobalt (Co), manganese (Mn) as the subcomponent. ), antimony (Sb), _Bi 2 _O 3 nickel (Ni) are each _{oxide, Co 2 O 3, MnO,} Sb 2 O 3, in terms of NiO _Bi 2 _{O 3} of 0.5 mol%, Co ₂ O _3, MnO, respectively, 1.0mol%, _Sb 2 _{O 3} of 1.5 mol%, 2 mol% of NiO, and 0.003 mol% in terms Al a _{(NO 3) 3 · 9H 2} O in ^{Al 3+} Each was weighed and added. Further, Ag ₂ O was added to the basic composition so as to contain 0.001 to 0.1 wt%, and a current-voltage nonlinear resistor was manufactured by the method shown in the first embodiment. .

The life characteristics of these current-voltage nonlinear resistors were evaluated. In the lifetime characteristic evaluation, the voltage (V _{1 mA} ) when a current of 1 mA flows is continuously applied for 3000 h in the atmosphere at 120 ° C., and the rate of change in leakage current (Ir) when V _{1 mA} before and after that is applied It was measured.

Where the rate of change is

(I _r (after 3000 h) −I _r (initial value)) / I _r (initial value) × 100

If the value of the leakage current change rate is a negative value, it indicates that the life characteristics of the current-voltage nonlinear resistor are excellent. The leakage current change rate is shown in Table 4 below. In Table 4, * indicates a sample outside the scope of the present invention.

As is apparent from Table 4, when the content of Ag ₂ O is 0.005 to 0.05 wt%, the rate of change in leakage current becomes a negative value, and a current-voltage nonlinear resistor having excellent life characteristics is obtained. It is clear that it is obtained. In the present embodiment, only the basic composition has an effect of adding Ag to the life characteristics. However, the same effect can be obtained within the basic composition range of claims 1 to 3.

(5) Fifth Embodiment Corresponding to Claim 5 A fifth embodiment will be described with reference to Table 5. In the fifth embodiment, B ₂ O ₃ is added to the raw material of the first embodiment so as to contain 0.001 to 0.1 wt%.

In the fifth embodiment, the subcomponent content of the current-voltage nonlinear resistor is ZnS as the main component, and finally bismuth (Bi), cobalt (Co), manganese (Mn ), Antimony (Sb), and nickel (Ni) are converted to oxides Bi ₂ O ₃ , Co ₂ O ₃ , MnO, Sb ₂ O ₃ , and NiO, respectively, and Bi ₂ O ₃ is 0.5 mol%, Co. ₂ O _3, MnO, respectively, 1.0mol%, _Sb 2 _{O 3} of 1.5 mol%, 2 mol% of NiO, and 0.003 mol% in terms Al a _{(NO 3) 3 · 9H 2} O in ^{Al 3+} Each was weighed and added. Further, B ₂ O ₃ is added to the basic composition so as to contain 0.001 to 0.1 wt%, and a current-voltage nonlinear resistor is manufactured by the method shown in the first embodiment. did.

The life characteristics of these current-voltage nonlinear resistors were evaluated by the method shown in the fourth embodiment. The leakage current change rate is shown in Table 5 below. In Table 5, * indicates a sample that is outside the scope of the present invention. As can be seen from Table 5, when the content of B ₂ O ₃ is 0.005 to 0.05 wt%, the rate of change in leakage current becomes a negative value, and the current-voltage nonlinear resistor has excellent life characteristics. Is clearly obtained.

That is, the lifetime characteristics of the current-voltage nonlinear resistor can be significantly improved by adding 0.005 to 0.05 wt% of Ag and B individually or simultaneously. In the basic composition alone according to the first aspect, the life characteristics may be insufficient when the electric charging rate (the voltage applied to the current-voltage nonlinear resistor) is set high. By adding, the change in leakage current with time is reduced and the life characteristics are improved. When the addition amounts of Ag and B are each converted to Ag ₂ O or boron (B) is converted to B ₂ O ₃ and less than 0.005 wt%, the effect of improving the life characteristics can be obtained. Absent. On the other hand, if it exceeds 0.05 wt%, the life characteristics are deteriorated.

In the present embodiment, only the basic composition has the effect of adding boron B to the life characteristics. However, the same effect can be obtained in the basic composition range of claims 1 to 4.

(6) Sixth Embodiment Corresponding to Claim 6 The sixth embodiment will be described with reference to Table 6. The sixth embodiment focuses on the α-Bi ₂ O ₃ phase (orthorhombic system) in the Bi ₂ O ₃ crystal phase in the sintered body.

In the sixth embodiment, bismuth (Bi), cobalt (Co), manganese (Mn) are finally used as subcomponents with respect to ZnO having the subcomponent contents of the current-voltage nonlinear resistor as the main components. , Antimony (Sb), and nickel (Ni) are converted to Bi ₂ O ₃ , Co ₂ O ₃ , MnO, Sb ₂ O ₃ , and NiO, which are oxides, respectively, and Bi ₂ O ₃ is 0.5 mol%, Co _2. O _3, MnO, respectively, 1.0mol%, _Sb 2 _{O 3} of 1.5 mol%, respectively NiO, 2mol%, Al (NO 3) 3 and · 9H ₂ O in terms of ^{Al 3+} 0.003 mol% Then, each was weighed and added, and a current-voltage nonlinear resistor was produced by the method shown in the first embodiment.

Here, when forming a side insulation layer, changing the ratio of _{Bi 2 O 3 α-Bi 2} O 3 crystalline phase contained in the crystal by changing the heat treatment conditions. Further, the produced current - carried a powder X-ray diffraction evaluation of the sintered body of the voltage non-linear resistor, the ratio of α-Bi ₂ O ₃ crystalline phase contained in the Bi ₂ O ₃ crystal by X-ray intensity peak ratio Calculated.

  The life characteristics of these current-voltage nonlinear resistors were evaluated by the method shown in the fourth embodiment. The leakage current change rate is shown in Table 6 below. In Table 6, * indicates a sample that is outside the scope of the present invention.

Included in Table 6 reveals that Bi ₂ O ₃ crystal as α-Bi ₂ O ₃ rate of change of the leakage current by the ratio of crystalline phase to 80% or more becomes a negative value, the better life characteristics It is clear that a current-voltage nonlinear resistor is obtained.

That is, the crystal form of the Bi ₂ O ₃ phase in the sintered body changes depending on the heat treatment conditions when forming the side insulating layer, and greatly affects the stability of the electrical characteristics of the ZnO crystal grain boundary. Therefore, sufficient life characteristics can be obtained when the α-Bi ₂ O ₃ phase (orthorhombic system) in the Bi ₂ O ₃ crystal phase in the sintered body is less than 80% of the total Bi ₂ O ₃ phase. Can not.

In the present embodiment, only the basic composition has an effect on the life characteristics of the Bi ₂ O ₃ crystal phase. However, the same effect can be obtained in the basic composition range of claims 1 to 5.

(7) Seventh Embodiment Corresponding to Claim 7 The seventh embodiment will be described with reference to Table 7. The seventh embodiment is characterized in that a current-voltage nonlinear resistor is obtained by firing a raw material having the composition shown in each of the above embodiments at a temperature of 1200 ° C. or lower.

In the present embodiment, bismuth (Bi), cobalt (Co), manganese (Mn), antimony are finally added as auxiliary components to ZnO as the main component content of the current-voltage nonlinear resistor. (Sb), nickel (Ni), and yttrium (Y) are converted to Bi ₂ O ₃ , Co ₂ O ₃ , MnO, Sb ₂ O ₃ , and NiO, which are oxides, respectively, and Bi ₂ O ₃ is 0.5 mol%. , _Co 2 _O 3, MnO, respectively, 1.0mol%, _Sb 2 _{O 3} of 1.5 mol%, 2 _mol% of _NiO, 0.4 mol% of _{Y 2 O 3, Al (NO} 3) 3 · 9H 2 O Was converted to Al ³⁺ and weighed so as to be 0.003 mol%, and each was added to produce a current-voltage nonlinear resistor by the method described in the first embodiment. In this case, the firing temperature was changed to 1160-1230 ° C.

  These current-voltage non-linear resistors were evaluated for thermal stability by the method shown in the first embodiment. Table 7 below shows the high temperature leakage current and the operation start voltage representing the thermal stability. In Table 7, * indicates a sample outside the scope of the present invention.

  As is apparent from Table 7, it is clear that a current-voltage nonlinear resistor having a low high-temperature leakage current and excellent thermal stability can be obtained by setting the firing temperature to 1200 ° C. or less. On the other hand, when the temperature during firing of the current-voltage nonlinear resistor is 1200 ° C. or higher, the operation start voltage is lowered and the thermal stability is lowered.

In the present embodiment, only the basic composition has been shown to have an effect on the thermal stability of the firing temperature at the time of firing, but similar effects can be obtained if the basic composition range is set in claims 1 to 6.

(8) Eighth Embodiment ... corresponding to Claim 8 This embodiment relates to a lightning arrester using the current-voltage nonlinear resistor shown in the first to seventh embodiments. That is, as shown in FIG. 2, the lightning arrester of the present embodiment accommodates the current-voltage non-linear resistor manufactured under the conditions shown in the first to seventh embodiments in a tank-shaped metal container 4. An insulating medium such as an insulating gas is enclosed.

  In FIG. 2, 4 is a tank-shaped metal container that serves as an outer cover of the lightning arrester, 5 is a non-linear resistance laminate that is insulated and supported therein, and 6 is provided close to the non-linear resistance laminate 5. A shield, 7 is an insulating spacer for insulatingly supporting the non-linear resistive laminate 5 with respect to the metal container 4, and 8 is also supported by the insulating spacer 7 and is connected to the non-linear resistive laminate 5 and other gas arresters. It is a metal fitting for connection with a high voltage conductor of an insulated electric device.

  According to the eighth embodiment having such a configuration, the current-voltage nonlinear resistance laminate 5 housed inside the metal container 4 of the lightning arrester is as shown in the first to seventh embodiments. Since the operation start voltage is high and the thermal stability is excellent, it is possible to reduce the size of the non-linear resistance laminate 5 and the metal container 4 that accommodates it, thereby obtaining a small lightning arrester.

(9) Ninth embodiment ... corresponding to claim 9 In this embodiment, in the lightning arrester shown in the eighth embodiment, at least the trunk portion of the container for storing the non-linear resistance laminated body is disposed as a pipe. It is comprised by insulating members, such as.

  In FIG. 3, reference numeral 9 denotes an insulating container serving as a jacket of the lightning arrester, and is constituted by a ceramic member such as a soot tube or a synthetic resin as an example. Reference numeral 10 denotes a non-linear resistance multilayer body that is insulated and supported therein, 11 a shield provided close to the non-linear resistance multilayer body 10, 12 an upper terminal, and 13 a lower terminal. Insulating gas is sealed in the gap between the insulating container 9 and the non-linear resistance laminate 10 inside.

  Also in the ninth embodiment having such a configuration, the current-voltage nonlinear resistance laminate 10 housed inside the insulating container 9 of the lightning arrester is as shown in the first to seventh embodiments. Since the operation start voltage of the current-voltage nonlinear resistor is high and the thermal stability is excellent, a small lightning arrester can be obtained.

(10) Tenth Embodiment Corresponding to Claim 10 This embodiment is the lightning arrester shown in the ninth embodiment, wherein the insulating container 14 is provided with a through hole 15, and this By placing a lightning arrester with a non-linear resistance laminate enclosed in such an insulating container in an insulating material such as separately prepared insulation oil, the insulation environment is the same as the surroundings of the lightning arrester, and the non-linear resistance laminate is insulated. It is intended.

  That is, FIG. 4 shows that the current-voltage non-linear resistance laminate 10 manufactured under the conditions shown in the first to seventh embodiments is housed in a container 14 having at least a body portion formed of an insulating member, and is not shown in the drawing. It is stored in an insulating medium such as oil. Incidentally, such a lightning arrester is used in a state where it is housed together with other high-voltage conductors or windings in an insulating device such as an oil-filled transformer or a switch.

  The configuration of the lightning arrester of the tenth embodiment is the same as that of the lightning arrester shown in the ninth embodiment except that the insulating container 14 and the entire lightning arrester are used in insulating oil. It is. However, the space in the insulating container 14 is filled with the same insulating medium (insulating gas or insulating oil) as the outside through the through hole 15.

  Also in the tenth embodiment having such a configuration, the operation start voltage of the current-voltage nonlinear resistor is high and the thermal stability is excellent, so that the portion can be downsized. As a result, a small lightning arrester can be obtained.

1 shows a cross-sectional view of a current-voltage nonlinear resistor according to the present invention. Sectional drawing of 8th Embodiment of the lightning arrester concerning this invention is shown. Sectional drawing of 9th Embodiment of the lightning arrester concerning this invention is shown. Sectional drawing of 10th Embodiment of the lightning arrester concerning this invention is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Sintered body 2 ... Side insulating layer 3 ... Electrode 4 ... Tank-shaped metal container 5 ... Non-linear resistance laminated body 6 ... Shield 7 ... Insulating spacer 8 ... Connection metal fitting 9 ... Insulating container 10 ... Non-linear resistance laminated body DESCRIPTION OF SYMBOLS 11 ... Shield 12 ... Upper terminal 13 ... Lower terminal 14 ... Insulating container 15 ... Through-hole

Claims (10)

Zinc oxide (ZnO) is the main component, and bismuth (Bi), cobalt (Co), manganese (Mn), antimony (Sb), and nickel (Ni) are the oxides Bi ₂ O ₃ and Co _{2, respectively.} O _{3, MnO,} in terms of _{Sb 2 O 3, NiO, 0.3~1.0mol} % of _Bi 2 _{O 3, 0.3~1.5mol%} of _Co 2 _{O 3, 0.1~} the MnO 2 mol%, 0.5 to 2.5 mol% of Sb ₂ O ₃ and 0.5 to ₃ mol% of NiO, and the relative ratios of bismuth and antimony, manganese and cobalt are converted into oxides, respectively. A current-voltage nonlinear resistor comprising a sintered body with 15 <Bi ₂ O ₃ / Sb ₂ O ₃ <1.0 and 0.3 <MnO / Co ₂ O ₃ <3.5. Oxidation of at least one rare earth element R of yttrium (Y), europium (Eu), erbium (Er), thulium (Tm), gadolinium (Gd), dysprodium (Dy), holmium (Ho), ytterbium (Yb) The current-voltage nonlinear resistor according to claim 1, wherein the product contains 0.01 to 1.0 mol% in terms of R ₂ O ₃ . The current-voltage nonlinear resistor according to claim 1 or 2, comprising a sintered body containing 0.001 to 0.015 mol% of aluminum in terms of Al3 ⁺ . Voltage non - current according to any one of claims 1 to 3, characterized in that a sintered body of silver in terms of Ag ₂ O containing 0.005 to 0.05%. 4. The current-voltage nonlinear resistor according to claim 1, comprising a sintered body containing 0.005 to 0.05 wt% of boron in terms of B ₂ O ₃ . The α-Bi ₂ O ₃ phase (orthorhombic system) in the Bi ₂ O ₃ crystal phase in the sintered body accounts for 80% or more of the total Bi ₂ O ₃ phase. The current-voltage nonlinear resistor according to any one of 5.   The current-voltage nonlinear resistor according to any one of claims 1 to 5, wherein firing is performed at a temperature of 1200 ° C or lower.   A non-linear resistance laminate formed by laminating the current-voltage non-linear resistors according to any one of claims 1 to 7 is housed in a metal container, and an insulating medium is enclosed in the metal container. And a lightning arrester.   A non-linear resistance laminate formed by laminating the current-voltage non-linear resistor according to any one of claims 1 to 7 is housed in a container having at least a body portion made of an insulating material, A lightning arrester characterized by encapsulating an insulating medium in the box.   A non-linear resistance laminate formed by laminating the current-voltage non-linear resistors according to any one of claims 1 to 7 is housed in a container having at least a body portion made of an insulating material, A lightning arrester characterized by being enclosed in an insulating medium.

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