JPH11273905A - Current-limiting device constituted of connecting plural ptc element plates in parallel - Google Patents
Current-limiting device constituted of connecting plural ptc element plates in parallelInfo
- Publication number
- JPH11273905A JPH11273905A JP7784598A JP7784598A JPH11273905A JP H11273905 A JPH11273905 A JP H11273905A JP 7784598 A JP7784598 A JP 7784598A JP 7784598 A JP7784598 A JP 7784598A JP H11273905 A JPH11273905 A JP H11273905A
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- Prior art keywords
- ptc element
- plates
- ptc
- plate
- temperature
- Prior art date
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- Thermistors And Varistors (AREA)
- Emergency Protection Circuit Devices (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、送配電系統に流れ
る短絡電流あるいは過負荷電流等の過電流から送配電系
統あるいは送配電系統に配設された電力機器を保護する
ための限流器に係わり、特にＰＴＣ素子を用いた限流器
に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a current limiting device for protecting a power transmission / distribution system or power equipment disposed in the power transmission / distribution system from an overcurrent such as a short circuit current or an overload current flowing through the power transmission / distribution system. In particular, the present invention relates to a current limiter using a PTC element.
【０００２】[0002]
【従来の技術】近年、送配電系統に流れる短絡電流ある
いは過負荷電流等の過電流から送配電系統あるいは送配
電系統に配設した電力機器を保護するために、温度が上
昇することにより抵抗値が増大する正の抵抗温度係数を
有する素子（ＰＴＣ（PositiveTemperature Coefficien
t）サーミスタ、以下ＰＴＣ素子という）を送配電系統
の電路に用いることが提案されるようになった。2. Description of the Related Art In recent years, in order to protect a power transmission / distribution system or power equipment disposed in the power transmission / distribution system from an overcurrent such as a short-circuit current or an overload current flowing through the power transmission / distribution system, the resistance value increases due to an increase in temperature. Having a positive temperature coefficient of resistance (PTC (Positive Temperature Coefficien)
t) A thermistor, hereinafter referred to as a PTC element) has been proposed to be used for an electric circuit of a power transmission and distribution system.
【０００３】このＰＴＣ素子を送配電系統に遮断器と併
設して用いた場合、例えば、何らかの理由により、この
系統に定格電流以上の過電流が流れると、ＰＴＣ素子内
にジュール熱が発生してＰＴＣ素子の温度が上昇する。
すると、このＰＴＣ素子は正の抵抗温度係数を有するた
め、ＰＴＣ素子の温度が所定の抵抗転移温度（あるいは
相転移温度：以下、抵抗転移温度という）以上になる
と、その抵抗値が急激に増大してこの系統に流れる過電
流を抑制（限流）するようになる。その後、遮断器が動
作して回路が遮断される。一方、事故が回復した後、Ｐ
ＴＣ素子の温度が常温に戻ると、その抵抗値は元の低抵
抗値になるため、ＰＴＣ素子は自動復帰し、遮断器が再
投入されると、この系統には通常の所定の負荷電流が流
れるようになる。[0003] When this PTC element is used in conjunction with a circuit breaker in a power transmission and distribution system, for example, if an overcurrent exceeding the rated current flows through this system for some reason, Joule heat is generated in the PTC element. The temperature of the PTC element increases.
Then, since this PTC element has a positive temperature coefficient of resistance, when the temperature of the PTC element becomes higher than a predetermined resistance transition temperature (or phase transition temperature: hereinafter, referred to as a resistance transition temperature), the resistance value sharply increases. The overcurrent flowing through the lever system is suppressed (current limit). Thereafter, the circuit breaker operates to cut off the circuit. On the other hand, after the accident has recovered,
When the temperature of the TC element returns to normal temperature, the resistance value returns to the original low resistance value, so that the PTC element automatically recovers, and when the circuit breaker is turned on again, a normal predetermined load current is applied to this system. It will flow.
【０００４】ところで、この種のＰＴＣ素子は母材であ
るセラミックスに導電材料を混入させて焼結して作製さ
れる。導電材料を混入する際には、母材であるセラミッ
クスに均一に分散するように混入させるが、大きな断面
積を有するＰＴＣ素子を作製する場合は、導電材料が均
一に分散した素子を得ることが難しく、断面の各部位で
それぞれ異なる抵抗値のＰＴＣ素子が形成されるように
なる。このように、断面の各部位でそれぞれ異なる抵抗
値を有するＰＴＣ素子に電流を流した場合、異なる抵抗
値に起因して、断面の各部位の電流密度にばらつきを生
じる。A PTC element of this type is manufactured by mixing a conductive material into a ceramic as a base material and sintering the mixed material. When mixing the conductive material, it is mixed so as to be uniformly dispersed in the ceramic as the base material. However, when manufacturing a PTC element having a large cross-sectional area, it is necessary to obtain an element in which the conductive material is uniformly dispersed. It is difficult, and PTC elements having different resistance values are formed at respective portions of the cross section. As described above, when a current flows through a PTC element having a different resistance value at each portion of the cross section, the current density at each portion of the cross section varies due to the different resistance value.
【０００５】電流密度にばらつきを生じると、当然、ジ
ュール熱に基づく自己発熱も断面の各部位でそれぞれ異
なることとなる。このため、ＰＴＣ素子内部に急激な温
度勾配が形成され、各部位で熱膨張差が生じて、やがて
は、ＰＴＣ素子が破壊されるという問題を生じた。[0005] If the current density varies, the self-heating based on the Joule heat naturally differs in each part of the cross section. For this reason, a steep temperature gradient is formed inside the PTC element, and a difference in thermal expansion occurs in each part, which eventually causes a problem that the PTC element is broken.
【０００６】そこで、素子の破壊を防止することができ
るＰＴＣ素子が特開平８−２３６３０３号公報にて提案
されるようになった。この特開平８−２３６３０３号公
報で提案されたＰＴＣ素子はＰＴＣ素子を細分化し、こ
の細分化された各ＰＴＣ素子をハニカム状の隔壁によっ
て隔てるようにしている。このように、隔壁によって各
ＰＴＣ素子を隔てるようにすると、１つのＰＴＣ素子が
破壊されたとしても、この破壊は隔壁によって遮断され
るようになるので、ＰＴＣ素子全体としては破壊に至ら
ないようになる。Therefore, a PTC element capable of preventing the element from being broken has been proposed in Japanese Patent Application Laid-Open No. 8-236303. The PTC element proposed in Japanese Patent Application Laid-Open No. H8-236303 subdivides the PTC element, and separates the subdivided PTC elements by honeycomb-shaped partition walls. As described above, if each PTC element is separated by a partition, even if one PTC element is destroyed, this destruction is interrupted by the partition, so that the PTC element as a whole is not destroyed. Become.
【０００７】[0007]
【発明が解決しようとする課題】しかしながら、上述し
た特開平８−２３６３０３号公報にて提案されたＰＴＣ
素子にあっては、細分化された各ＰＴＣ素子の抵抗率あ
るいは形状（例えば、断面積、長さ）等が考慮されてい
ないため、隔壁により細分化された各ＰＴＣ素子の抵抗
値はそれぞれまちまちとなってばらつきがある。このた
め、短絡電流などの過電流がこのような隔壁により細分
化された各ＰＴＣ素子により構成された限流器に流れる
場合、各ＰＴＣ素子の温度上昇はまちまちとなって、限
流器としては温度分布を持つこととなる。However, the PTC proposed in the above-mentioned Japanese Patent Application Laid-Open No. 8-236303 has been proposed.
In the element, since the resistivity or shape (for example, cross-sectional area, length) of each subdivided PTC element is not taken into account, the resistance value of each subdivided PTC element by the partition wall varies. There is a variation. For this reason, when an overcurrent such as a short-circuit current flows through a current limiting device constituted by each PTC element subdivided by such a partition, the temperature rise of each PTC element varies, and as a current limiting device, It will have a temperature distribution.
【０００８】ここで、各ＰＴＣ素子の抵抗値のばらつき
が大きい場合、この限流器に短絡電流などの過電流が流
れると、限流器内で急激な温度勾配が生じて、この限流
器が破壊されるという事態を生じる。また、各ＰＴＣ素
子の抵抗値のばらつきが大きい場合、抵抗値が低いＰＴ
Ｃ素子に電流が集中するようになるため、この電流が集
中したＰＴＣ素子は電流が集中したことにより、ジュー
ル熱が発生して抵抗転移温度に至るようになる。Here, when the resistance value of each PTC element has a large variation, when an overcurrent such as a short-circuit current flows through the current limiting device, a sharp temperature gradient occurs in the current limiting device, and the current limiting device Will be destroyed. In addition, when the variation in the resistance value of each PTC element is large, the PT
Since the current concentrates on the C element, the PTC element on which the current concentrates generates Joule heat due to the concentration of the current and reaches the resistance transition temperature.
【０００９】これにより、電流が集中したＰＴＣ素子は
抵抗が急激に増大して限流効果を発揮するようになる
が、他の抵抗値が高いＰＴＣ素子は抵抗転移温度に至ら
ず、限流効果を発揮することができないこととなる。こ
の結果、限流器としては一部のＰＴＣ素子のみが限流効
果を発揮するだけであるので、限流器全体として所定の
限流効果を発揮することができないという問題を生じ
る。As a result, the PTC element in which the current is concentrated has a sudden increase in resistance and exhibits a current limiting effect. However, other PTC elements having a high resistance value do not reach the resistance transition temperature and have a current limiting effect. Cannot be exhibited. As a result, since only a part of the PTC elements exerts the current limiting effect as the current limiting device, there is a problem that the predetermined current limiting effect cannot be exerted as the entire current limiting device.
【００１０】[0010]
【課題を解決するための手段およびその作用・効果】本
発明は、ＰＴＣ素子を細分化して用いて各ＰＴＣ素子の
集合体としても、この集合体を構成する各ＰＴＣ素子の
抵抗値および体積を揃えれば、集合体内の温度分布も均
一になるという知見に基づいてなされたものであって、
各ＰＴＣ素子がその抵抗転移温度に同時に達することが
できるようにして、各ＰＴＣ素子が十分に限流効果が発
揮できる限流器を得られるようにすることをその目的と
してなされたものである。Means for Solving the Problems and Action / Effect of the Invention The present invention is directed to a method of dividing a PTC element into a plurality of PTC elements to form an aggregate of the PTC elements. It is based on the knowledge that if they are aligned, the temperature distribution in the aggregate will be uniform,
It is an object of the present invention to enable each PTC element to simultaneously reach its resistance transition temperature and to obtain a current limiter in which each PTC element can sufficiently exhibit a current limiting effect.
【００１１】このため、本発明の限流器は、常温におけ
る抵抗率が等しい複数のＰＴＣ素子板が一体的に成形さ
れたＰＴＣ素子集合体を備え、この一体的に成形された
ＰＴＣ素子集合体の各ＰＴＣ素子板を並列に接続すると
ともに、ＰＴＣ素子集合体の各ＰＴＣ素子板の通電方向
の長さを等しくするとともにその断面積も等しくし、温
度上昇時の各ＰＴＣ素子板の温度分布を均一にして各Ｐ
ＴＣ素子板が一斉に抵抗転移温度に達するようにしてい
る。For this reason, the current limiter of the present invention comprises a PTC element aggregate formed integrally with a plurality of PTC element plates having the same resistivity at normal temperature, and the PTC element aggregate formed integrally. Are connected in parallel with each other, the lengths of the PTC element plates of the PTC element assembly in the conduction direction are made equal and their cross-sectional areas are also made equal, and the temperature distribution of each PTC element plate when the temperature rises is reduced. Make each P uniform
The TC element plates simultaneously reach the resistance transition temperature.
【００１２】このように、常温における抵抗率が等しい
ＰＴＣ素子板のみを選択してＰＴＣ素子集合体を形成
し、このＰＴＣ素子集合体の各ＰＴＣ素子板の長さおよ
び断面積を等しくすると、各ＰＴＣ素子板の抵抗も等し
くなる。このため、このＰＴＣ素子集合体を用いて限流
器を構成すると、この限流器に短絡電流などの過電流が
流れると、限流器内の各ＰＴＣ素子板は一斉に温度上昇
して、一様に抵抗転移温度に至るので、限流器内で温度
勾配が生じることはなくなり、この限流器が破壊される
という事態も生じることがない。As described above, only PTC element plates having the same resistivity at room temperature are selected to form a PTC element assembly, and when the PTC element plates of the PTC element assembly have the same length and cross-sectional area, The resistance of the PTC element plate is also equal. For this reason, when a current limiting device is configured using this PTC element assembly, when an overcurrent such as a short-circuit current flows through the current limiting device, the temperature of each PTC element plate in the current limiting device increases at the same time, Since the resistance transition temperature is reached uniformly, a temperature gradient does not occur in the current limiting device, and the current limiting device does not break down.
【００１３】また、本発明の限流器は、常温における抵
抗率が異なる複数のＰＴＣ素子板が一体的に成形された
ＰＴＣ素子集合体を備え、この一体的に成形されたＰＴ
Ｃ素子集合体の各ＰＴＣ素子板を並列に接続するととも
に、常温における抵抗率が大きいＰＴＣ素子板の断面積
を常温における抵抗率が小さいＰＴＣ素子板の断面積よ
り大きくし、かつ、常温における抵抗率が大きいＰＴＣ
素子板の通電方向の長さを常温における抵抗率が小さい
ＰＴＣ素子板の通電方向の長さより短くして各ＰＴＣ素
子板の体積を等しくし、温度上昇時の各ＰＴＣ素子板の
温度分布を均一にして各ＰＴＣ素子板が一斉に抵抗転移
温度に達するようにしている。Further, the current limiter of the present invention comprises a PTC element assembly in which a plurality of PTC element plates having different resistivities at normal temperature are integrally formed, and the integrally formed PT element is provided.
The PTC element plates of the C element assembly are connected in parallel, and the cross-sectional area of the PTC element plate having a large resistivity at room temperature is made larger than the cross-sectional area of the PTC element plate having a small resistivity at room temperature, and the resistance at room temperature is increased. PTC with high rate
The length of the element plate in the energizing direction is shorter than the length of the PTC element plate having a small resistivity at room temperature in the energizing direction to equalize the volume of each PTC element plate and make the temperature distribution of each PTC element plate uniform when the temperature rises. Thus, the PTC element plates simultaneously reach the resistance transition temperature.
【００１４】このように、常温における抵抗率が異なる
ＰＴＣ素子板を用いてＰＴＣ素子集合体を形成した場合
は、常温における抵抗率が大きいＰＴＣ素子の断面積を
常温における抵抗率が小さいＰＴＣ素子の断面積より大
きくするとともに、常温における抵抗率が大きいＰＴＣ
素子板の通電方向の長さを常温における抵抗率が小さい
ＰＴＣ素子板の通電方向の長さより短くして各ＰＴＣ素
子板の体積を等しくすれば、各ＰＴＣ素子板の抵抗も等
しくなる。このため、このＰＴＣ素子集合体を用いて限
流器を構成しても、この限流器に短絡電流などの過電流
が流れると、限流器内の各ＰＴＣ素子板は一斉に温度上
昇して、一様に抵抗転移温度に至るので、限流器内で温
度勾配が生じることはなくなり、この限流器が破壊され
るという事態も生じることがない。As described above, when a PTC element aggregate is formed using PTC element plates having different resistivity at ordinary temperature, the cross-sectional area of the PTC element having large resistivity at ordinary temperature is reduced by the cross-sectional area of the PTC element having small resistivity at ordinary temperature. PTC with larger resistivity than normal area
If the lengths of the PTC element plates in the energization direction are shorter than the lengths of the PTC element plates having a small resistivity at room temperature in the energization direction and the volumes of the PTC element plates are made equal, the resistance of each PTC element plate also becomes equal. For this reason, even if a current limiter is formed using this PTC element assembly, when an overcurrent such as a short-circuit current flows through the current limiter, the temperature of each PTC element plate in the current limiter rises all at once. Since the temperature reaches the resistance transition temperature uniformly, no temperature gradient is generated in the current limiting device, and the current limiting device does not break down.
【００１５】そして、複数のＰＴＣ素子板を高絶縁材料
により一体化してＰＴＣ素子集合体とすれば、各ＰＴＣ
素子板の各々は高絶縁材料により絶縁されるようにな
る。このため、例え、何れかのＰＴＣ素子板が損傷した
としても、この損傷が他のＰＴＣ素子板に及ぶことが防
止できるようになる。この結果、このようなＰＴＣ素子
集合体を用いて構成した限流器の信頼性が向上する。When a plurality of PTC element plates are integrated with a highly insulating material to form a PTC element assembly,
Each of the element plates becomes insulated by the highly insulating material. Therefore, even if one of the PTC element plates is damaged, it is possible to prevent the damage from affecting other PTC element plates. As a result, the reliability of the current limiter configured using such a PTC element assembly is improved.
【００１６】[0016]
【発明の実施の形態】以下に、図に基づいて本発明の限
流器の一実施形態を説明する。なお、図１は本実施形態
の限流器の概略構成を模式的に示す図であり、図１
（ａ）は斜示図であり、図１（ｂ）はそのＸ−Ｘ断面を
示す断面図である。また、図２は本実施形態の変形例の
限流器の概略構成を模式的に示す図であり、図２（ａ）
は斜示図であり、図２（ｂ）はそのＹ−Ｙ断面を示す断
面図である。さらに、図３は図１および図２の限流器の
各ＰＴＣ素子板相互の電気的接続状態を示すとともに遮
断器と共に系統に接続した状態を示す回路図である。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the current limiting device according to the present invention will be described below with reference to the drawings. FIG. 1 is a diagram schematically showing a schematic configuration of the current limiting device of the present embodiment.
FIG. 1A is a perspective view, and FIG. 1B is a cross-sectional view showing the XX section. FIG. 2 is a diagram schematically showing a schematic configuration of a current limiter according to a modification of the present embodiment.
Is a perspective view, and FIG. 2B is a cross-sectional view showing a YY cross section thereof. FIG. 3 is a circuit diagram showing a state of electrical connection between the respective PTC element plates of the current limiter of FIGS. 1 and 2 and a state of being connected to a system together with a circuit breaker.
【００１７】本発明の限流器１０ａは、図１に示すよう
に、ＰＴＣ素子板（ＰＴＣ１）１１、ＰＴＣ素子板（Ｐ
ＴＣ２）１２、ＰＴＣ素子板（ＰＴＣ３）１３、ＰＴＣ
素子板（ＰＴＣ４）１４、ＰＴＣ素子板（ＰＴＣ５）１
５、ＰＴＣ素子板（ＰＴＣ６）１６、ＰＴＣ素子板（Ｐ
ＴＣ７）１７、ＰＴＣ素子板（ＰＴＣ８）１８およびＰ
ＴＣ素子板（ＰＴＣ９）１９の複数のＰＴＣ素子板を高
絶縁材料Ｓ（例えば、エポキシ樹脂等の耐熱性樹脂）に
より一体的に成形したＰＴＣ素子集合体１０を用いて構
成される。As shown in FIG. 1, the current limiting device 10a of the present invention comprises a PTC element plate (PTC1) 11, a PTC element plate (PTC1).
TC2) 12, PTC element plate (PTC3) 13, PTC
Element plate (PTC4) 14, PTC element plate (PTC5) 1
5, PTC element plate (PTC6) 16, PTC element plate (P
TC7) 17, PTC element plate (PTC8) 18 and P
A plurality of PTC element plates of the TC element plate (PTC9) 19 are formed using a PTC element assembly 10 integrally formed of a high-insulation material S (for example, a heat-resistant resin such as an epoxy resin).
【００１８】ここで、一般的に、抵抗素子の抵抗値はそ
の断面積に比例して小さくなり、その長さに比例して大
きくなるので、抵抗率を有する材料を低抵抗で使用しよ
うとする場合は断面積を広くするとともにその長さを短
くする必要がある。そのため、本実施形態の各ＰＴＣ素
子板１１〜１９は薄板状に形成されており、この薄板状
の各ＰＴＣ素子板１１〜１９の上下面に上部端子板と下
部端子板とを接続した構造を採用している。Here, in general, the resistance value of a resistance element decreases in proportion to its cross-sectional area and increases in proportion to its length. Therefore, an attempt is made to use a material having resistivity at a low resistance. In this case, it is necessary to increase the cross-sectional area and shorten the length. Therefore, each of the PTC element plates 11 to 19 of the present embodiment is formed in a thin plate shape, and a structure in which an upper terminal plate and a lower terminal plate are connected to the upper and lower surfaces of the thin PTC element plates 11 to 19, respectively. Has adopted.
【００１９】具体的には、ＰＴＣ素子板１１の上面部お
よび下面部には上部端子板１１ａおよび下部端子板１１
ｂが接続されており、ＰＴＣ素子板１２の上面部および
下面部には上部端子板１２ａおよび下部端子板１２ｂが
接続されている。同様に、ＰＴＣ素子板１３には上部端
子板１３ａおよび下部端子板１３ｂが、ＰＴＣ素子板１
４には上部端子板１４ａおよび下部端子板１４ｂが、Ｐ
ＴＣ素子板１５には上部端子板１５ａおよび下部端子板
１５ｂ（図示せず）が、ＰＴＣ素子板１６には端子板１
６ａおよび下部端子板１６ｂが、ＰＴＣ素子板１７には
上部端子板１７ａおよび下部端子板１７ｂが、ＰＴＣ素
子板１８には上部端子板１８ａおよび下部端子板１８ｂ
（図示せず）が、ＰＴＣ素子板１９には上部端子板１９
ａおよび下部端子板１９ｂがそれぞれ接続されている。Specifically, an upper terminal plate 11a and a lower terminal plate 11a are provided on the upper and lower surfaces of the PTC element plate 11, respectively.
b is connected, and an upper terminal plate 12a and a lower terminal plate 12b are connected to the upper surface and the lower surface of the PTC element plate 12, respectively. Similarly, the PTC element plate 13 includes an upper terminal plate 13a and a lower terminal plate 13b.
4 has an upper terminal plate 14a and a lower terminal plate 14b,
The TC element board 15 has an upper terminal board 15a and a lower terminal board 15b (not shown), and the PTC element board 16 has a terminal board 1
6a and lower terminal plate 16b, PTC element plate 17 has upper terminal plate 17a and lower terminal plate 17b, and PTC element plate 18 has upper terminal plate 18a and lower terminal plate 18b.
(Not shown), but the upper terminal plate 19
a and the lower terminal board 19b are connected to each other.
【００２０】そして、上部端子板１１ａ，１４ａ，１７
ａは第１接続導体３１にて接続され、上部端子板１２
ａ，１５ａ，１８ａは第２接続導体３２にて接続され、
上部端子板１３ａ，１６ａ，１９ａは第３接続導体３３
にて接続されている。一方、下部端子板１１ｂ，１４
ｂ，１７ｂは第４接続導体３４（図示せず）にて接続さ
れ、下部端子板１２ｂ，１５ｂ，１８ｂは第５接続導体
３５（図示せず）にて接続され、下部端子板１３ｂ，１
６ｂ，１９ｂは第６接続導体３６にて接続されいる。The upper terminal plates 11a, 14a, 17
a is connected by the first connection conductor 31 and the upper terminal plate 12
a, 15a, 18a are connected by a second connection conductor 32,
The upper terminal plates 13a, 16a, and 19a are the third connection conductors 33.
Connected at On the other hand, the lower terminal plates 11b, 14
b, 17b are connected by a fourth connection conductor 34 (not shown), the lower terminal plates 12b, 15b, 18b are connected by a fifth connection conductor 35 (not shown), and the lower terminal plates 13b, 1
6b and 19b are connected by a sixth connection conductor 36.
【００２１】これらの第１接続導体３１、第２接続導体
３２および第３接続導体３３は電源側接続導体３７で接
続され、第４接続導体３４、第５接続導体３５および第
６接続導体３６は負荷側接続導体３８で接続されてい
る。これにより、各ＰＴＣ素子板１１〜１９はそれぞれ
電気的に並列に接続された限流器１０ａが構成されるこ
ととなる。The first connection conductor 31, the second connection conductor 32, and the third connection conductor 33 are connected by a power supply side connection conductor 37, and the fourth connection conductor 34, the fifth connection conductor 35, and the sixth connection conductor 36 are connected to each other. They are connected by a load-side connection conductor 38. As a result, each of the PTC element plates 11 to 19 constitutes a current limiter 10a electrically connected in parallel.
【００２２】各ＰＴＣ素子板１１〜１９を形成するＰＴ
Ｃ素子としては、常温抵抗率ρ（例えば、ρ＝０．１Ω
・ｃｍ）が小さいとともに、常温抵抗率に対する抵抗上
昇率（例えば、常温抵抗率ρの４０００倍）が大きく、
かつその抵抗転移温度が２００〜２４０℃程度のクリス
トバライト系セラミックスを用いることが好ましい。こ
のクリストバライト系セラミックスからなるＰＴＣ素子
は、素子温度が２００〜２４０℃の抵抗転移温度になる
とその抵抗率（ρ）が最大になる。そして、本実施形態
においては、このクリストバライト系セラミックスから
なるＰＴＣ素子を薄板状に形成して各ＰＴＣ素子板１１
〜１９としている。PT forming each PTC element plate 11-19
As the C element, the room temperature resistivity ρ (for example, ρ = 0.1Ω)
Cm) is small, and the rate of increase in resistance with respect to the normal temperature resistivity (for example, 4000 times the normal temperature resistivity ρ) is large,
It is preferable to use a cristobalite-based ceramic having a resistance transition temperature of about 200 to 240 ° C. When the element temperature reaches a resistance transition temperature of 200 to 240 ° C., the resistivity (ρ) of the PTC element made of cristobalite ceramics becomes maximum. In the present embodiment, the PTC element made of cristobalite-based ceramics is formed in a thin plate shape and each PTC element plate 11
~ 19.
【００２３】なお、ＰＴＣ素子としては、クリストバラ
イト系セラミックス以外に、Ｃｒ2Ｏ3あるいはＡｌ2Ｏ3
を固溶したＶ2Ｏ3系セラミックス、チタン酸鉛（ＰｂＴ
ｉＯ3）セラミックス、チタン酸ビスマス（ＢｉＴｉ
Ｏ3）セラミックスあるいはこれらの固溶体を用いても
よい。As the PTC element, other than cristobalite ceramics, Cr 2 O 3 or Al 2 O 3
V 2 O 3 based ceramics obtained by solid solution of lead titanate (PBT
iO 3 ) ceramics, bismuth titanate (BiTi)
O 3 ) ceramics or solid solutions thereof may be used.
【００２４】なお、各ＰＴＣ素子板１１〜１９の上下面
に接続する両端子板（１１ａ，１１ｂ、１２ａ，１２
ｂ、１３ａ，１３ｂ、１４ａ，１４ｂ、１５ａ，１５
ｂ、１６ａ，１６ｂ、１７ａ，１７ｂ、１８ａ，１８
ｂ、１９ａ，１９ｂ）は、例えば銅、アルミニウム、ス
テンレス等の導電性が良好でかつ熱伝導性が良好な金属
を板状に形成している。そして、各ＰＴＣ素子板１１〜
１９の厚み方向に電流が流れるように、これらの両端子
板を各ＰＴＣ素子板１１〜１９の厚み方向にサンドイッ
チ状に挟み込んで、導電性接着剤による接着、ロウ付け
あるいは溶接等により固着して各ＰＴＣ素子板１１〜１
９と一体化している。このように両端子板を各ＰＴＣ素
子板１１〜１９に接続すると、薄板状の各ＰＴＣ素子板
１１〜１９の通電方向はその厚み方向になるため、この
各ＰＴＣ素子板１１〜１９内に負荷電流が流れても通電
抵抗が減少してその電力損失は小さくなる。The two terminal plates (11a, 11b, 12a, 12a) connected to the upper and lower surfaces of each of the PTC element plates 11 to 19, respectively.
b, 13a, 13b, 14a, 14b, 15a, 15
b, 16a, 16b, 17a, 17b, 18a, 18
b, 19a, and 19b) are formed of a metal having good conductivity and good heat conductivity, such as copper, aluminum, and stainless steel, in a plate shape. And each PTC element plate 11-
These two terminal plates are sandwiched in the thickness direction of each of the PTC element plates 11 to 19 so that a current flows in the thickness direction of 19, and are fixed by bonding with an electrically conductive adhesive, brazing or welding. Each PTC element plate 11-1
9 and integrated. When the two terminal plates are connected to the PTC element plates 11 to 19 in this manner, the direction of conduction of the thin plate-shaped PTC element plates 11 to 19 becomes the thickness direction. Even if a current flows, the conduction resistance is reduced and the power loss is reduced.
【００２５】ここで、ＰＴＣ素子を薄板状に形成するに
際しては、母材であるセラミックスに導電材料（例え
ば、タングステン（Ｗ）、ニッケル（Ｎｉ）、二ケイ化
モリブデン（ＭｏＳｉ2）、二ケイ化タングステン（Ｗ
Ｓｉ2）など）を混入させて焼結して作製される。導電
材料を混入する際には、母材であるセラミックスに均一
に分散するように混入させるが、大きな断面積を有する
ＰＴＣ素子板を作製する場合は、導電材料が均一に分散
した素子を得ることが難しく、断面の各部位でそれぞれ
異なる抵抗値のＰＴＣ素子板が形成されるようになる。
このため、本発明においては、同一の厚み（長さ）で薄
板状に形成されたＰＴＣ素子板の常温での抵抗率を測定
し、抵抗率が等しいＰＴＣ素子板１１〜１９のみを選択
して用いてＰＴＣ素子集合体１０としている。Here, when the PTC element is formed in a thin plate shape, a conductive material (for example, tungsten (W), nickel (Ni), molybdenum disilicide (MoSi 2 ), disilicide Tungsten (W
Si 2 ) is mixed and sintered. When mixing the conductive material, it is mixed so as to be uniformly dispersed in the ceramic as the base material, but when manufacturing a PTC element plate having a large cross-sectional area, it is necessary to obtain an element in which the conductive material is uniformly dispersed. Therefore, PTC element plates having different resistance values are formed at respective portions of the cross section.
For this reason, in the present invention, the resistivity at room temperature of a PTC element plate formed into a thin plate with the same thickness (length) is measured, and only the PTC element plates 11 to 19 having the same resistivity are selected. The PTC element assembly 10 is used.
【００２６】このように、同一の厚み（長さ）で抵抗率
が等しいＰＴＣ素子板１１〜１９のみを選択して用いて
ＰＴＣ素子集合体１０とし、このＰＴＣ素子集合体１０
を用いて限流器１０ａとすると、この限流器１０ａに短
絡電流のような過電流が流れると、過電流に基づくジュ
ール熱により、この限流器１０ａ内の各ＰＴＣ素子板１
１〜１９は一斉に温度上昇して抵抗転移温度に至るよう
になるので、限流器１０ａ内に温度勾配を生じることは
ない。なお、常温での抵抗率が等しいＰＴＣ素子はその
長さおよび断面積を同一にすれば抵抗値が等しくなるの
で、抵抗転移温度に至る時間も等しくなる。このため、
常温での抵抗率が等しいＰＴＣ素子のみを選択して用い
るようにすれば、このＰＴＣ素子のみで形成されたＰＴ
Ｃ素子集合体の各ＰＴＣ素子は一斉に温度上昇して、一
斉に抵抗転移温度に至るものである。As described above, only the PTC element plates 11 to 19 having the same thickness (length) and the same resistivity are selected and used to form the PTC element assembly 10.
When an overcurrent such as a short-circuit current flows through the current limiter 10a, Joule heat based on the overcurrent causes each PTC element plate 1 in the current limiter 10a to
Since the temperatures of 1 to 19 rise simultaneously to reach the resistance transition temperature, a temperature gradient does not occur in the current limiter 10a. Since the PTC elements having the same resistivity at room temperature have the same resistance value if the length and the cross-sectional area are the same, the time required to reach the resistance transition temperature is also equal. For this reason,
If only the PTC elements having the same resistivity at normal temperature are selected and used, the PT formed only by the PTC elements can be used.
The temperature of each PTC element of the C element assembly rises all at once, and reaches the resistance transition temperature all at once.
【００２７】上述したように、本実施形態においては、
常温での抵抗率が等しいＰＴＣ素子板１１〜１９のみを
選択して用いてＰＴＣ素子集合体１０としているので、
このＰＴＣ素子集合体１０を用いて限流器１０ａとすれ
ば、各ＰＴＣ素子板１１〜１９は一斉に温度上昇するこ
とが可能となるので、限流器１０ａ内の温度勾配に起因
する限流器の破壊を防止できるようになる。As described above, in this embodiment,
Since only the PTC element plates 11 to 19 having the same resistivity at room temperature are selected and used to form the PTC element assembly 10,
If the PTC element assembly 10 is used as the current limiting device 10a, the temperature of each of the PTC element plates 11 to 19 can be increased at the same time, so that the current limiting device 10a due to the temperature gradient in the current limiting device 10a can be used. It can prevent the destruction of the vessel.
【００２８】変形例、上述した実施形態の限流器１０ａ
においては、常温での抵抗率が等しいＰＴＣ素子板１１
〜１９のみを選択して用いてＰＴＣ素子集合体１０を構
成し、このＰＴＣ素子集合体１０の各ＰＴＣ素子板１１
〜１９を一斉に温度上昇させ、各ＰＴＣ素子板１１〜１
９を同時に抵抗転移温度に至らせるようにしたが、常温
での抵抗率が異なるＰＴＣ素子板を用いても、各ＰＴＣ
素子板を一斉に温度上昇させ、各ＰＴＣ素子板を同時に
抵抗転移温度に至らせることも可能である。Modification, current limiting device 10a of the above-described embodiment
, The PTC element plate 11 having the same resistivity at normal temperature
To 19 are selected and used to form a PTC element assembly 10, and each PTC element plate 11 of the PTC element assembly 10
To 19 are simultaneously heated, and each PTC element plate 11 to 1
9 are simultaneously brought to the resistance transition temperature. However, even if PTC element plates having different resistivity
It is also possible to raise the temperature of the element plates at the same time and to simultaneously bring each PTC element plate to the resistance transition temperature.
【００２９】本変形例の限流器２０ａは、図２に示すよ
うに、ＰＴＣ素子板（ＰＴＣ１）２１、ＰＴＣ素子板
（ＰＴＣ２）２２、ＰＴＣ素子板（ＰＴＣ３）２３、Ｐ
ＴＣ素子板（ＰＴＣ４）２４、ＰＴＣ素子板（ＰＴＣ
５）２５、ＰＴＣ素子板（ＰＴＣ６）２６、ＰＴＣ素子
板（ＰＴＣ７）２７、ＰＴＣ素子板（ＰＴＣ８）２８お
よびＰＴＣ素子板（ＰＴＣ９）２９の複数のＰＴＣ素子
板を高絶縁材料Ｓ（例えば、エポキシ樹脂等の耐熱性樹
脂）により一体的に成形したＰＴＣ素子集合体２０を用
いて構成される。As shown in FIG. 2, the current limiting device 20a of this modification includes a PTC element plate (PTC1) 21, a PTC element plate (PTC2) 22, a PTC element plate (PTC3) 23,
TC element plate (PTC4) 24, PTC element plate (PTC4)
5) PTC element plates (PTC6) 26, PTC element plates (PTC7) 27, PTC element plates (PTC8) 28, and PTC element plates (PTC9) 29 are made of a high insulation material S (for example, epoxy). (A heat-resistant resin such as a resin).
【００３０】ここで、本変形例においては、薄板状に形
成されたＰＴＣ素子板の常温での抵抗率を測定し、この
常温での抵抗率が大きいＰＴＣ素子板の断面積は大きく
するとともに厚み（長さ）を短く（ＰＴＣ素子板２２，
２４，２９）なるようにその断面積および厚み（長さ）
を調整し、常温での抵抗率が中位のＰＴＣ素子板の断面
積は中位で厚み（長さ）も中位（ＰＴＣ素子板２１，２
６，２８）になるようにその断面積および厚み（長さ）
を調整し、常温での抵抗率が小さいＰＴＣ素子板の断面
積は小さくするとともに厚み（長さ）を長く（ＰＴＣ素
子板２３，２５，２７）なるようにその断面積および厚
み（長さ）を調整している。In this modification, the resistivity of a thin PTC element plate at room temperature is measured, and the cross-sectional area of the PTC element plate having a large resistivity at room temperature is increased and the thickness is increased. (PTC element plate 22,
24, 29) so that its cross-sectional area and thickness (length)
The cross-sectional area of the PTC element plate having a medium resistivity at room temperature is medium and the thickness (length) is medium (the PTC element plates 21 and 22).
6, 28), its cross-sectional area and thickness (length)
Is adjusted so that the cross-sectional area of the PTC element plate having a small resistivity at normal temperature is reduced, and the cross-sectional area and thickness (length) of the PTC element plate are increased so that the thickness (length) becomes longer (PTC element plates 23, 25, 27). Has been adjusted.
【００３１】なお、１０ｍｍ四方で厚みが１ｍｍのＰＴ
Ｃ素子板の常温での抵抗率を測定すると、１５〜４５ｍ
Ω・ｃｍとなり、そのばらつきは３倍程度になる。した
がって、抵抗率が大きいＰＴＣ素子板の断面積は抵抗率
が小さいＰＴＣ素子板の断面積の３1/2倍程度にすれば
よく、その厚み（長さ）を１／３1/2倍程度にすればよ
い。A 10 mm square PT having a thickness of 1 mm
When the resistivity of the C element plate at room temperature is measured, it is 15 to 45 m.
Ω · cm, and the variation is about three times. Therefore, the cross-sectional area of the PTC element plate having a large resistivity should be about 31/2 times the cross-sectional area of the PTC element plate having a small resistivity, and the thickness (length) thereof should be about 1/3 1/2 times. What should I do?
【００３２】このように、抵抗率が異なるＰＴＣ素子板
２１〜２９を用いても、それぞれのＰＴＣ素子板２１〜
２９の断面積および厚み（長さ）が異って同一の体積と
なるため、結果的に各ＰＴＣ素子板２１〜２９の抵抗は
等しくなる。このため、このような各ＰＴＣ素子板２１
〜２９を用いてＰＴＣ素子集合体２０とし、このＰＴＣ
素子集合体２０を用いて限流器２０ａとしても、この限
流器２０ａに短絡電流のような過電流が流れると、過電
流に基づくジュール熱により、この限流器２０ａ内の各
ＰＴＣ素子板２１〜２９は一斉に温度上昇して抵抗転移
温度に至るようになるので、限流器２０ａ内に温度勾配
を生じることはない。As described above, even if the PTC element plates 21 to 29 having different resistivities are used, each of the PTC element plates 21 to 29 can be used.
Since the cross-sectional area and thickness (length) of the PTC element plates 29 are different and have the same volume, the resistance of each of the PTC element plates 21 to 29 becomes equal. Therefore, each such PTC element plate 21
To 29, a PTC element assembly 20 is formed.
Even if an overcurrent such as a short-circuit current flows through the current limiter 20a by using the element assembly 20, even if the PTC element plate in the current limiter 20a is generated by Joule heat based on the overcurrent, Since the temperatures of the resistors 21 to 29 rise at the same time to reach the resistance transition temperature, a temperature gradient does not occur in the current limiter 20a.
【００３３】本変形例においても上述した実施形態と同
様に、薄板状の各ＰＴＣ素子板２１〜２９の上下面に上
部端子板と下部端子板とを接続した構造を採用してい
る。具体的には、ＰＴＣ素子板２１の上面部および下面
部には上部端子板２１ａおよび下部端子板２１ｂが接続
されており、ＰＴＣ素子板２２の上面部および下面部に
は上部端子板２２ａおよび下部端子板２２ｂが形成され
ている。In this modified example, as in the above-described embodiment, a structure in which an upper terminal plate and a lower terminal plate are connected to the upper and lower surfaces of each of the thin PTC element plates 21 to 29 is adopted. Specifically, an upper terminal plate 21a and a lower terminal plate 21b are connected to the upper surface and the lower surface of the PTC element plate 21, and the upper terminal plate 22a and the lower terminal A terminal plate 22b is formed.
【００３４】同様に、ＰＴＣ素子板２３には上部端子板
２３ａおよび下部端子板２３ｂが、ＰＴＣ素子板２４に
は上部端子板２４ａおよび下部端子板２４ｂが、ＰＴＣ
素子板２５には上部端子板２５ａおよび下部端子板２５
ｂ（図示せず）が、ＰＴＣ素子板２６には端子板２６ａ
および下部端子板２６ｂが、ＰＴＣ素子板２７には上部
端子板２７ａおよび下部端子板２７ｂが、ＰＴＣ素子板
２８には上部端子板２８ａおよび下部端子板２８ｂが、
ＰＴＣ素子板２９には上部端子板２９ａおよび下部端子
板２９ｂがそれぞれ接続されている。Similarly, the PTC element plate 23 has an upper terminal plate 23a and a lower terminal plate 23b, and the PTC element plate 24 has an upper terminal plate 24a and a lower terminal plate 24b.
The element plate 25 includes an upper terminal plate 25a and a lower terminal plate 25a.
b (not shown), the PTC element plate 26 has a terminal plate 26a.
And the lower terminal plate 26b, the upper terminal plate 27a and the lower terminal plate 27b on the PTC element plate 27, the upper terminal plate 28a and the lower terminal plate 28b on the PTC element plate 28,
An upper terminal plate 29a and a lower terminal plate 29b are connected to the PTC element plate 29, respectively.
【００３５】そして、断面積が大きくて厚み（長さ）が
薄いＰＴＣ素子板２２，２４，２９の下部端子板２２
ｂ，２４ｂ，２９ｂは断面積が大きくて厚みを厚くし、
断面積が中位で厚み（長さ）も中位のＰＴＣ素子板２
１，２６，２８の下部端子板２１ｂ，２６ｂ，２８ｂは
断面積が中位で厚みも中位にし、断面積が小さくて厚み
（長さ）が厚いＰＴＣ素子板２３，２５，２７の下部端
子板２３ｂ，２５ｂ，２７ｂは断面積が小さくて厚みを
薄くして、上部端子板から下部端子板までの長さを等し
くしている。なお、各ＰＴＣ素子板の厚み（長さ）を変
えた場合、上記のように下部端子板の厚みを変えて上部
端子板から下部端子板までの長さを等しくしても、ある
いは上部端子板と下部端子板の両方の厚みを変えて上部
端子板から下部端子板までの長さが等しくなるようにし
てもよい。The lower terminal plate 22 of the PTC element plates 22, 24, 29 having a large sectional area and a small thickness (length).
b, 24b, 29b have a large cross-sectional area and a large thickness,
PTC element plate 2 with medium cross-sectional area and medium thickness (length)
The lower terminal plates 21b, 26b, 28b of 1, 26, 28 have a medium cross-sectional area and a medium thickness, and the lower terminals of the PTC element plates 23, 25, 27 having a small cross-sectional area and a large thickness (length). The plates 23b, 25b, and 27b have a small cross-sectional area and a small thickness so that the lengths from the upper terminal plate to the lower terminal plate are equal. When the thickness (length) of each PTC element plate is changed, the thickness of the lower terminal plate may be changed to make the length from the upper terminal plate to the lower terminal plate equal as described above, or the upper terminal plate may be changed. The thickness from the upper terminal plate to the lower terminal plate may be made equal by changing the thickness of both the and the lower terminal plate.
【００３６】また、上述した実施形態と同様にして、上
部端子板２１ａ，２４ａ，２７ａは第１接続導体３１に
て接続され、上部端子板２２ａ，２５ａ，２８ａは第２
接続導体３２にて接続され、上部端子板２３ａ，２６
ａ，２９ａは第３接続導体３３にて接続されいる。一
方、下部端子板２１ｂ，２４ｂ，２７ｂは第４接続導体
３４（図示せず）にて接続され、下部端子板２２ｂ，２
５ｂ，２８ｂは第５接続導体３５（図示せず）にて接続
され、下部端子板２３ｂ，２６ｂ，２９ｂは第６接続導
体３６にて接続されいる。In the same manner as in the above-described embodiment, the upper terminal plates 21a, 24a, 27a are connected by the first connection conductor 31, and the upper terminal plates 22a, 25a, 28a are connected to the second terminal conductors.
The upper terminal plates 23a, 26
a and 29a are connected by a third connection conductor 33. On the other hand, the lower terminal plates 21b, 24b, 27b are connected by a fourth connection conductor 34 (not shown), and are connected to the lower terminal plates 22b, 2b.
5b and 28b are connected by a fifth connection conductor 35 (not shown), and the lower terminal plates 23b, 26b and 29b are connected by a sixth connection conductor 36.
【００３７】これらの第１接続導体３１、第２接続導体
３２および第３接続導体３３は電源側接続導体３７で接
続され、第４接続導体３４、第５接続導体３５および第
６接続導体３６は負荷側接続導体３８で接続されてい
る。これにより、各ＰＴＣ素子板２１〜２９はそれぞれ
電気的に並列に接続された限流器２０ａが構成されるこ
ととなる。The first connection conductor 31, the second connection conductor 32 and the third connection conductor 33 are connected by a power supply side connection conductor 37, and the fourth connection conductor 34, the fifth connection conductor 35 and the sixth connection conductor 36 They are connected by a load-side connection conductor 38. As a result, the PTC element plates 21 to 29 constitute the current limiter 20a electrically connected in parallel.
【００３８】各ＰＴＣ素子板２１〜２９を形成するＰＴ
Ｃ素子としては、上述した実施形態と同様な材料により
構成され、また各ＰＴＣ素子板２１〜２９の上下面に接
続する両端子板（２１ａ，２１ｂ、２２ａ，２２ｂ、２
３ａ，２３ｂ、２４ａ，２４ｂ、２５ａ，２５ｂ、２６
ａ，２６ｂ、２７ａ，２７ｂ、２８ａ，２８ｂ、２９
ａ，２９ｂ）は、上述した実施形態と同様な銅、アルミ
ニウム、ステンレス等の導電性が良好でかつ熱伝導性が
良好な金属を板状に形成している。PT for forming each of the PTC element plates 21 to 29
The C element is made of the same material as in the above-described embodiment, and has two terminal plates (21a, 21b, 22a, 22b, 2a) connected to the upper and lower surfaces of each of the PTC element plates 21 to 29.
3a, 23b, 24a, 24b, 25a, 25b, 26
a, 26b, 27a, 27b, 28a, 28b, 29
In a, 29b), a metal having good conductivity and good heat conductivity, such as copper, aluminum, and stainless steel, similar to the above-described embodiment is formed in a plate shape.
【００３９】上述したように、本変形例においては、上
述した実施形態と同様に、各ＰＴＣ素子板２１〜２９は
一斉に温度上昇することが可能となるので、限流器２０
ａ内の温度勾配に起因する限流器の破壊を防止できるよ
うになる。As described above, in the present modified example, similarly to the above-described embodiment, the temperature of each of the PTC element plates 21 to 29 can be raised at the same time.
Thus, it is possible to prevent the current limiter from being broken due to the temperature gradient in “a”.
【００４０】ついで、上述した各限流器１０ａ，２０ａ
をＭＣＣＢ（遮断器）とともに電力系統に配設して、短
絡電流などの過電流から電力系統あるいは電力系統に配
設された電力機器を保護する例を図３に基づいて説明す
る。なお、図３のＭＣＣＢ（遮断器）３０は、限流器１
０ａ（あるいは２０ａ）の負荷側に配設され、図示しな
い系統Ｌに接続される主接点、主接点を開閉する開閉機
構、主接点の開極時に発生するアークを消弧するための
消弧室、過負荷電流または短絡電流に対して開閉機構を
釈放して主接点を引き外す引き外し装置等と、開閉機構
を動作させて主接点を電路に投入する操作スイッチ等を
備えている。Next, each of the current limiting devices 10a, 20a
An example of protecting the power system or power devices disposed in the power system from overcurrent such as short-circuit current by arranging the power system in a power system together with an MCCB (circuit breaker) will be described with reference to FIG. The MCCB (breaker) 30 in FIG.
A main contact, which is arranged on the load side of 0a (or 20a) and is connected to a system L (not shown), an opening / closing mechanism for opening / closing the main contact, an arc-extinguishing chamber for extinguishing an arc generated when the main contact is opened. A trip device for releasing the switching mechanism in response to an overload current or a short-circuit current to trip the main contact, and an operation switch for operating the switching mechanism to put the main contact into the electric circuit.
【００４１】そして、限流器１０ａ（あるいは２０ａ）
の負荷側接続導体３８をＭＣＣＢ３０の電源側端子に接
続し、限流器１０ａ（あるいは２０ａ）の電源側接続導
体３７を系統Ｌの電源側に接続している。ついで、上記
のように接続した限流器１０ａ（あるいは２０ａ）を備
えたＭＣＣＢ（遮断器）３０の動作を説明する。Then, the current limiting device 10a (or 20a)
Is connected to the power supply side terminal of the MCCB 30, and the power supply side connection conductor 37 of the current limiter 10a (or 20a) is connected to the power supply side of the system L. Next, the operation of the MCCB (breaker) 30 including the current limiter 10a (or 20a) connected as described above will be described.
【００４２】まず、正常時の動作について説明すると、
図示しない操作スイッチを操作して開閉機構を動作させ
て主接点を電路に投入すると、系統電力が限流器１０ａ
（あるいは２０ａ）およびＭＣＣＢ３０を通して図示し
ない負荷に供給され、この系統に定格電流以下の負荷電
流が流れるようになる。このとき、限流器１０ａ（ある
いは２０ａ）のＰＴＣ素子集合体１０（あるいは２０）
の抵抗値は小さいため、電力損失を伴うことなく負荷に
電力が供給される。First, the normal operation will be described.
When the main switch is turned on by operating an opening / closing mechanism by operating an operation switch (not shown), the system power is supplied to the current limiter 10a.
(Or 20a) and a load not shown through the MCCB 30 so that a load current equal to or less than the rated current flows through this system. At this time, the PTC element assembly 10 (or 20) of the current limiter 10a (or 20a)
Has a small resistance value, power is supplied to the load without power loss.
【００４３】ここで、何らかの理由により系統の負荷側
に過負荷電流が流れる異常時になると、限流器１０ａ
（あるいは２０ａ）のＰＴＣ素子集合体１０（あるいは
２０）には定格電流の１．２５〜１０倍の過負荷電流が
流れ、そのジュール熱によりＰＴＣ素子集合体１０（あ
るいは２０）の各ＰＴＣ素子板１１〜１９（２１〜２
９）が一斉に発熱する。Here, if an overload current flows to the load side of the system for some reason, the current limiter 10a
An overload current of 1.25 to 10 times the rated current flows through the PTC element assembly 10 (or 20) of the PTC element assembly 10 (or 20a). 11-19 (21-2
9) generates heat all at once.
【００４４】しかしながら、過負荷電流はそれほど大き
な電流ではないため、ＰＴＣ素子集合体１０（あるいは
２０）に長時間にわたって過負荷電流が流れ、各ＰＴＣ
素子板１１〜１９（２１〜２９）が一斉に発熱しても、
各ＰＴＣ素子板１１〜１９（２１〜２９）は抵抗転移温
度（Ｔｃ＝２００〜２４０℃）に達することはない。こ
のとき、ＭＣＣＢ３０に長時間にわたって定格電流の
１．２５〜１０倍の過負荷電流が継続して流れると、こ
の過負荷電流に対応して予め設定された時間（１０秒〜
１２０分）が経過すると、ＭＣＣＢ３０の引き外し装置
は動作して開閉機構を釈放して主接点を引き外し、負荷
側は電源より遮断されて系統に過負荷電流が流れなくな
る。However, since the overload current is not so large, the overload current flows through the PTC element assembly 10 (or 20) for a long time,
Even if the element plates 11 to 19 (21 to 29) generate heat all at once,
Each of the PTC element plates 11 to 19 (21 to 29) does not reach the resistance transition temperature (Tc = 200 to 240 ° C.). At this time, if an overload current of 1.25 to 10 times the rated current continuously flows through the MCCB 30 for a long time, a preset time (10 seconds to 10 seconds) corresponding to the overload current is used.
After elapse of 120 minutes), the tripping device of the MCCB 30 operates to release the switching mechanism and trip the main contact, and the load side is cut off from the power supply so that no overload current flows to the system.
【００４５】一方、系統の負荷側に短絡事故が生じて短
絡電流が流れる異常時になると、限流器１０ａ（あるい
は２０ａ）のＰＴＣ素子集合体１０（あるいは２０）に
過大な短絡電流が流れるため、各ＰＴＣ素子板１１〜１
９（２１〜２９）はそのジュール熱により一斉に発熱す
る。すると、この発熱により各ＰＴＣ素子板１１〜１９
（２１〜２９）は一斉に抵抗転移温度（２００〜２４０
℃）に達し、短絡電流を抑制（限流）する動作を開始す
る。そして、０．０２秒（５０Ｈｚの場合の１サイク
ル）以内にはＭＣＣＢ３０の主接点の開極動作が終了
し、負荷側は電源より遮断されて系統に短絡電流が流れ
なくなる。On the other hand, when a short circuit fault occurs on the load side of the system and a short circuit current flows, an abnormal short circuit current flows through the PTC element assembly 10 (or 20) of the current limiter 10a (or 20a). Each PTC element plate 11-1
9 (21 to 29) generates heat simultaneously due to the Joule heat. Then, due to this heat generation, each of the PTC element plates 11 to 19
(21-29) are simultaneously the resistance transition temperatures (200-240)
° C) and starts the operation of suppressing (current limiting) the short-circuit current. Then, within 0.02 seconds (one cycle in the case of 50 Hz), the opening operation of the main contact of the MCCB 30 ends, the load side is cut off from the power supply, and no short-circuit current flows to the system.
【００４６】以上に説明したように、本発明において
は、限流器１０ａ（あるいは２０ａ）のＰＴＣ素子集合
体１０（あるいは２０）の各ＰＴＣ素子板１１〜１９
（２１〜２９）は一斉に温度上昇することが可能となる
ので、限流器１０ａ（あるいは２０ａ）内の温度勾配に
起因する限流器の破壊を防止できるようになる。As described above, in the present invention, each of the PTC element plates 11 to 19 of the PTC element assembly 10 (or 20) of the current limiter 10a (or 20a) is provided.
Since (21 to 29) can simultaneously raise the temperature, it is possible to prevent the destruction of the current limiter caused by the temperature gradient in the current limiter 10a (or 20a).
【００４７】なお、上述した実施形態および変形例にお
いては、ＰＴＣ素子板を９枚用いてＰＴＣ素子集合体と
する例について説明したが、使用するＰＴＣ素子板の枚
数は適宜選択すればよい。また、上述した実施形態およ
び変形例においては、各ＰＴＣ素子板１１〜１９（２１
〜２９）およびＰＴＣ素子集合体１０（あるいは２０）
を矩形状にした例について説明したが、各ＰＴＣ素子板
およびＰＴＣ素子集合体の形状は円形等の他の形状にし
ても同様な効果を発揮する。In the above-described embodiment and modified examples, an example in which nine PTC element plates are used to form a PTC element assembly has been described. However, the number of PTC element plates to be used may be appropriately selected. In the above-described embodiment and modifications, each of the PTC element plates 11 to 19 (21
29) and the PTC element assembly 10 (or 20)
Has been described as a rectangular shape, but the same effect can be obtained even if the shape of each PTC element plate and the PTC element assembly is changed to another shape such as a circle.
【００４８】また、上述した実施形態および変形例にお
いては、各ＰＴＣ素子板１１〜１９（２１〜２９）のそ
れぞれの上下面に上部端子板と下部端子板を接続する例
について説明したが、ＰＴＣ素子集合体を形成した後、
このＰＴＣ素子集合体の上下面に１枚の上部端子板と１
枚の下部端子板をそれぞれ接続するようにしてもよい。Further, in the above-described embodiments and modified examples, an example in which the upper terminal plate and the lower terminal plate are connected to the upper and lower surfaces of each of the PTC element plates 11 to 19 (21 to 29) has been described. After forming the element assembly,
One upper terminal plate and one
The lower terminal plates may be connected to each other.
【図１】 本発明の実施形態の限流器の概略構成を模式
的に示す斜示図である。FIG. 1 is a perspective view schematically showing a schematic configuration of a current limiter according to an embodiment of the present invention.
【図２】 図１の実施形態の変形例の限流器の概略構成
を模式的に示す斜示図である。FIG. 2 is a perspective view schematically showing a schematic configuration of a current limiter according to a modification of the embodiment of FIG. 1;
【図３】 図１および図２の限流器の各ＰＴＣ素子相互
の電気的接続状態を示す回路図である。FIG. 3 is a circuit diagram showing a state of electrical connection between respective PTC elements of the current limiting device of FIGS. 1 and 2;
１０ａ…限流器、１０…ＰＴＣ素子集合体、１１〜１９
…ＰＴＣ素子板、１１ａ〜１９ａ…上部端子板、１１ｂ
〜１９ｂ…下部端子板、２０ａ…限流器、２０…ＰＴＣ
素子集合体、２１〜２９…ＰＴＣ素子板、２１ａ〜２９
ａ…上部端子板、２１ｂ〜２９ｂ…下部端子板、Ｓ…高
絶縁材料、３０…ＭＣＣＢ（遮断器）、３１…第１接続
導体、３２…第２接続導体、３３…第３接続導体、３４
…第４接続導体、３５…第５接続導体、３６…第６接続
導体、３７…電源側接続導体、３８…負荷側接続導体10a: Current limiter, 10: PTC element assembly, 11-19
... PTC element plate, 11a to 19a ... upper terminal plate, 11b
-19b: lower terminal plate, 20a: current limiter, 20: PTC
Element assembly, 21 to 29 ... PTC element plate, 21a to 29
a: Upper terminal plate, 21b to 29b: Lower terminal plate, S: High insulating material, 30: MCCB (circuit breaker), 31: First connection conductor, 32: Second connection conductor, 33: Third connection conductor, 34
... Fourth connection conductor, 35 ... Fifth connection conductor, 36 ... Sixth connection conductor, 37 ... Power supply side connection conductor, 38 ... Load side connection conductor
───────────────────────────────────────────────────── フロントページの続き (72)発明者 岡田 直剛 愛知県名古屋市瑞穂区須田町２番56号 日 本碍子株式会社内 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Naogo Okada 2-56 Suda-cho, Mizuho-ku, Nagoya-shi, Aichi Japan Inside Nihon Insulator Co., Ltd.
Claims (4)
所定の抵抗転移温度になると急激にその抵抗値が増大し
て前記過電流を抑制する正の抵抗温度係数を有する複数
のＰＴＣ素子板を並列接続して構成した限流器であっ
て、 常温における抵抗率が等しい前記複数のＰＴＣ素子板が
一体的に成形されたＰＴＣ素子集合体を備え、 前記一体的に成形されたＰＴＣ素子集合体の各ＰＴＣ素
子板を並列に接続するとともに、 前記ＰＴＣ素子集合体の各ＰＴＣ素子板の通電方向の長
さを等しくするとともにその断面積も等しくし、前記温
度上昇時の各ＰＴＣ素子板の温度分布を均一にして各Ｐ
ＴＣ素子板が一斉に前記抵抗転移温度に達するようにし
たことを特徴とする複数のＰＴＣ素子板を並列接続して
構成した限流器。1. A plurality of PTC element plates having a positive temperature coefficient of resistance for suppressing the overcurrent by rapidly increasing the temperature when a predetermined resistance transition temperature is reached by a rise in temperature due to the flow of the overcurrent. A current limiter configured by connecting in parallel, comprising: a PTC element assembly in which the plurality of PTC element plates having the same resistivity at normal temperature are integrally formed; and wherein the PTC element assembly is integrally formed. Are connected in parallel, the lengths of the PTC element plates of the PTC element assembly in the direction of conduction are equal, and the cross-sectional areas of the PTC element plates are also equalized. Make each distribution uniform
A current limiter comprising a plurality of PTC element plates connected in parallel, wherein the TC element plates simultaneously reach the resistance transition temperature.
所定の抵抗転移温度になると急激にその抵抗値が増大し
て前記過電流を抑制する正の抵抗温度係数を有する複数
のＰＴＣ素子板を並列接続して構成した限流器であっ
て、 常温における抵抗率が異なる前記複数のＰＴＣ素子板が
一体的に成形されたＰＴＣ素子集合体を備え、 前記一体的に成形されたＰＴＣ素子集合体の各ＰＴＣ素
子板を並列に接続するとともに、 常温における抵抗率が大きいＰＴＣ素子板の断面積を常
温における抵抗率が小さいＰＴＣ素子板の断面積より大
きくし、かつ、常温における抵抗率が大きいＰＴＣ素子
板の通電方向の長さを常温における抵抗率が小さいＰＴ
Ｃ素子板の通電方向の長さより短くして前記各ＰＴＣ素
子板の体積を等しくし、前記温度上昇時の各ＰＴＣ素子
板の温度分布を均一にして各ＰＴＣ素子板が一斉に前記
抵抗転移温度に達するようにしたことを特徴とする複数
のＰＴＣ素子板を並列接続して構成した限流器。2. A plurality of PTC element plates having a positive temperature coefficient of resistance that suppresses the overcurrent by increasing the temperature due to the flow of the overcurrent and suddenly increasing the resistance value when a predetermined resistance transition temperature is reached. A current limiter configured by connecting in parallel, comprising: a PTC element assembly in which the plurality of PTC element plates having different resistivity at normal temperature are integrally formed; Are connected in parallel, and the cross-sectional area of the PTC element plate having a large resistivity at room temperature is larger than the cross-sectional area of the PTC element plate having a small resistivity at room temperature, and the PTC having a large resistivity at room temperature. The length of the element plate in the conducting direction is set to PT with low resistivity at room temperature.
The length of each of the PTC element plates is made shorter by making the length of the C element plate in the conduction direction equal to that of the PTC element plates. The current limiter is constituted by connecting a plurality of PTC element plates in parallel, wherein
より一体化して前記ＰＴＣ素子集合体としたことを特徴
とする請求項１または請求項２に記載の複数のＰＴＣ素
子を並列接続して構成した限流器。3. The plurality of PTC element plates according to claim 1 or 2, wherein the plurality of PTC element plates are integrated with a highly insulating material to form the PTC element assembly. The configured current limiter.
かつ常温抵抗率に対する抵抗上昇率が大きいクリストバ
ライト系セラミックスであることを特徴とする請求項１
から請求項３のいずれかに記載の複数のＰＴＣ素子板を
並列接続して構成した限流器。4. A cristobalite-based ceramic having a low room temperature resistivity and a large resistance increasing ratio with respect to the room temperature resistivity.
A current limiter comprising a plurality of PTC element plates according to any one of claims 1 to 3 connected in parallel.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7784598A JPH11273905A (en) | 1998-03-25 | 1998-03-25 | Current-limiting device constituted of connecting plural ptc element plates in parallel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7784598A JPH11273905A (en) | 1998-03-25 | 1998-03-25 | Current-limiting device constituted of connecting plural ptc element plates in parallel |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH11273905A true JPH11273905A (en) | 1999-10-08 |
Family
ID=13645401
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7784598A Pending JPH11273905A (en) | 1998-03-25 | 1998-03-25 | Current-limiting device constituted of connecting plural ptc element plates in parallel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH11273905A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2016201383A (en) * | 2015-04-07 | 2016-12-01 | 富士電機株式会社 | Power semiconductor module and connecting pin |
| JPWO2019092834A1 (en) * | 2017-11-09 | 2020-11-12 | 三菱電機株式会社 | DC cutoff device |
| WO2020246147A1 (en) * | 2019-06-04 | 2020-12-10 | パナソニックＩｐマネジメント株式会社 | Lithium primary battery |
-
1998
- 1998-03-25 JP JP7784598A patent/JPH11273905A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2016201383A (en) * | 2015-04-07 | 2016-12-01 | 富士電機株式会社 | Power semiconductor module and connecting pin |
| JPWO2019092834A1 (en) * | 2017-11-09 | 2020-11-12 | 三菱電機株式会社 | DC cutoff device |
| US11233391B2 (en) | 2017-11-09 | 2022-01-25 | Mitsubishi Electric Corporation | DC interrupting device |
| WO2020246147A1 (en) * | 2019-06-04 | 2020-12-10 | パナソニックＩｐマネジメント株式会社 | Lithium primary battery |
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