JP2001268778A - Electronic overcurrent detection device - Google Patents
Electronic overcurrent detection deviceInfo
- Publication number
- JP2001268778A JP2001268778A JP2000079933A JP2000079933A JP2001268778A JP 2001268778 A JP2001268778 A JP 2001268778A JP 2000079933 A JP2000079933 A JP 2000079933A JP 2000079933 A JP2000079933 A JP 2000079933A JP 2001268778 A JP2001268778 A JP 2001268778A
- Authority
- JP
- Japan
- Prior art keywords
- capacitor
- current
- detection device
- overcurrent detection
- resistor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Emergency Protection Circuit Devices (AREA)
Abstract
Description
【0001】[0001]
【発明の属する技術分野】この発明は、配線用遮断器等
に適用される電子式過電流検出装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic overcurrent detection device applied to a circuit breaker for wiring or the like.
【0002】[0002]
【従来の技術】図3は、例えば特開平7−170651
号公報に示された従来の電子回路で構成された過電流検
出装置のブロック図である。図において、1は負荷へ電
流を通電する配電線、2は配電線1の電流を入・切する
開閉接点、3は配電線1の電流検出手段である変流器、
4は変流器2の二次側電流を演算処理に適した直流電圧
に変換するAC/DC変換回路、5はマイクロコンピュ
ータからなる演算処理部、6は演算処理部5等の作動電
力を供給する電源部である。7はコンデンサ、8はコン
デンサ7に並列接続された放電抵抗、10はコンパレー
タであり、コンデンサ7の電位eと予め設定される基準
電圧Eとを比較して「電位e>基準電圧E」になればト
リガ信号を出力する。9はコンパレータ10の基準電圧
を設定するツェナーダイオード、11は引外し回路、1
2は引外しコイルである。13は引外し機構であり、引
外し機構13に連繋するトリガ部材を引外しコイル12
が蹴脱することにより開閉接点2を開離して配電線1の
電流を遮断する。2. Description of the Related Art FIG.
FIG. 1 is a block diagram of an overcurrent detection device including a conventional electronic circuit disclosed in Japanese Patent Application Laid-Open Publication No. HEI 10-152139. In the figure, reference numeral 1 denotes a distribution line for supplying a current to a load, 2 denotes a switching contact for turning on / off the current of the distribution line 1, 3 denotes a current transformer serving as a current detecting means of the distribution line 1,
4 is an AC / DC conversion circuit for converting the secondary current of the current transformer 2 into a DC voltage suitable for arithmetic processing, 5 is an arithmetic processing unit including a microcomputer, and 6 is a power supply for operating the arithmetic processing unit 5 and the like. Power supply unit. Reference numeral 7 denotes a capacitor, 8 denotes a discharge resistor connected in parallel to the capacitor 7, and 10 denotes a comparator. The potential e of the capacitor 7 is compared with a preset reference voltage E to obtain "potential e> reference voltage E". Output a trigger signal. 9 is a Zener diode for setting a reference voltage of the comparator 10, 11 is a trip circuit, 1
2 is a tripping coil. Reference numeral 13 denotes a tripping mechanism, which trips a trigger member connected to the tripping mechanism 13 and trips the coil 12.
Is kicked off, the switching contact 2 is opened, and the current of the distribution line 1 is cut off.
【0003】次に動作について説明する。配電線1の電
流は変流器3により検出され、変流器3の二次側電流を
AC/DC変換回路4により直流電圧信号に変換する。
演算処理部5ではこの直流電圧信号の中から最大電流相
を選択し、最大電流に応じた電荷の電流信号にしてコン
デンサ7に出力しコンデンサ7を充電する。一方、コン
デンサ7に並列接続された放電抵抗8により、コンデン
サ7の電荷はコンデサ7と放電抵抗8の値で定まる時定
数で放電されている。放電抵抗8通じて放電する電荷よ
り演算処理部5からの充電電荷の方が多ければコンデン
サ7の電位eは上昇し、逆に、放電電荷より充電電荷の
方が少なければコンデンサ7の電位eは低下する。配電
線1の電流が多くなればコンデンサ7への充電電荷が多
くなり、コンデンサ7の電位eは基準電圧Eより高くな
り、コンパレータ10はトリガ信号を出力して開閉接点
2を開離して配電線1の電流を遮断して、配電線1およ
び配電線1に接続された負荷を過電流から保護する。Next, the operation will be described. The current of the distribution line 1 is detected by the current transformer 3, and the secondary current of the current transformer 3 is converted into a DC voltage signal by the AC / DC conversion circuit 4.
The arithmetic processing unit 5 selects the maximum current phase from the DC voltage signals, converts the DC current signal into a current signal having a charge corresponding to the maximum current, outputs the signal to the capacitor 7, and charges the capacitor 7. On the other hand, the charge of the capacitor 7 is discharged with a time constant determined by the values of the capacitor 7 and the discharge resistor 8 by the discharge resistor 8 connected in parallel to the capacitor 7. The potential e of the capacitor 7 increases if the charge from the arithmetic processing unit 5 is larger than the charge discharged through the discharge resistor 8. Conversely, if the charge is smaller than the discharge charge, the potential e of the capacitor 7 is descend. When the current in the distribution line 1 increases, the charge on the capacitor 7 increases, and the potential e of the capacitor 7 becomes higher than the reference voltage E. The comparator 10 outputs a trigger signal to open and close the on-off contact 2, and the distribution line 1 to protect the distribution line 1 and the load connected to the distribution line 1 from overcurrent.
【0004】配線用遮断器は配電線及び接続された負荷
を過電流から保護するものであり、通電履歴による温度
上昇による熱的保護の目的から、従来は電流検出素子と
してバイメタルが使用されていたが、電子式遮断器にお
いてこの熱的保護機能を持たせるものとして、上記のコ
ンデサ7と放電抵抗8からなる時定数回路で放熱シュミ
レートするコンデンサ7の残留電位を利用されるように
なってきた。A circuit breaker protects a distribution line and a connected load from an overcurrent, and a bimetal has been conventionally used as a current detecting element for the purpose of thermal protection due to a temperature rise due to a history of conduction. However, in order to provide the thermal protection function in the electronic circuit breaker, the residual potential of the capacitor 7 which simulates heat radiation by the time constant circuit including the capacitor 7 and the discharge resistor 8 has been used.
【0005】[0005]
【発明が解決しようとする課題】配線用遮断器は配電線
及び負荷の過電流焼損を防ぐ目的で設置される。配電線
及び負荷への許容電流は図4の配線用遮断器の温度補正
グラフに示すように周囲の環境温度により変化する。即
ち、環境温度が低いときは放熱が促進されるので定格電
流の100%以上の許容通電が可能であるが、環境温度
が高いときは定格電流の100%未満の許容となる。電
流検出素子としてバイメタルを使用している配線用遮断
器では通電許容電流はバイメタルの環境温度を加味した
変形を利用しての遮断時限特性を得ているので、環境温
度の変化に合致した通電許容電流となっている。A circuit breaker is installed for the purpose of preventing overcurrent burning of distribution lines and loads. The allowable current to the distribution line and the load changes according to the surrounding environmental temperature as shown in the temperature correction graph of the circuit breaker in FIG. That is, when the ambient temperature is low, heat dissipation is promoted, so that an allowable current of 100% or more of the rated current is possible. However, when the environmental temperature is high, the allowable current is less than 100% of the rated current. In a circuit breaker that uses a bimetal as a current detection element, the permissible current is obtained by using the deformation taking into account the environmental temperature of the bimetal to obtain the cut-off time characteristic. It is a current.
【0006】しかし、上記の電子式過電流検出装置で
は、コンデサ7と放電抵抗8からなる時定数回路で配電
線及び負荷の放熱シュミレートした時限で配線用遮断器
を動作させるようにしているので、環境温度を加味した
通電許容電流での遮断時限とならず、常温でも高温でも
同じ時限で遮断動作するので、特に環境温度が高温時の
配電線及び負荷の過熱保護に課題があった。However, in the above-described electronic overcurrent detection device, the circuit breaker for wiring is operated in a time period in which the heat of the distribution line and the load is simulated by the time constant circuit including the capacitor 7 and the discharge resistor 8. Since the cutoff operation does not take place at the allowable current carrying the current in consideration of the environmental temperature but at the same time at normal temperature or high temperature, there is a problem in overheating protection of distribution lines and loads especially at high environmental temperature.
【0007】この発明は、かかる課題を解決するための
ものであり、配線用遮断器の環境温度により遮断動作時
限が変化して環境温度が高温時の配電線及び負荷の過熱
保護に適する電子式過電流検出装置を提供することを目
的としている。An object of the present invention is to solve such a problem, and an electronic type suitable for overheating protection of a distribution line and a load when an environmental temperature is high due to a change in a cutoff operation time depending on an environmental temperature of a wiring breaker. An object of the present invention is to provide an overcurrent detection device.
【0008】[0008]
【課題を解決するための手段】この発明にかかる電子式
過電流検出装置は、配電線の通電電流を検出して、検出
された電流を演算処理して電流の大きさに対応する電荷
信号にして送出する演算処理部と、演算処理部からの電
荷を蓄電するコンデンサと、このコンデンサに並列接続
された正の温度特性を有する抵抗体からなる放電抵抗
と、上記コンデンサの電位と基準電圧とを比較して「コ
ンデンサの電位>基準電圧」になったとき信号出力する
ようにしたものである。SUMMARY OF THE INVENTION An electronic overcurrent detection device according to the present invention detects a current flowing through a distribution line, and calculates the detected current to generate a charge signal corresponding to the magnitude of the current. An arithmetic processing unit for transmitting and receiving the electric charge from the arithmetic processing unit, a discharge resistor including a resistor having a positive temperature characteristic connected in parallel to the capacitor, and a potential and a reference voltage of the capacitor. In comparison, a signal is output when “potential of capacitor> reference voltage”.
【0009】そして、放電抵抗を装置筐体外部の外気と
接する部位に配置したものである。[0009] The discharge resistor is disposed at a portion in contact with the outside air outside the device housing.
【0010】[0010]
【発明の実施の形態】実施の形態1.図1はこの発明の
実施の形態1を示す電子式過電流検出装置のブロック図
である。図において、1〜7、9〜13は上記従来装置
の説明と同様のものである。18はコンデンサ7と並列
接続された正の温度特性を有する放電抵抗である。正の
温度特性を有する抵抗体としてはサーミスタ等が適用で
きる。DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a block diagram of an electronic overcurrent detection device according to Embodiment 1 of the present invention. In the figure, reference numerals 1 to 7 and 9 to 13 are the same as those in the description of the conventional apparatus. Reference numeral 18 denotes a discharge resistor having a positive temperature characteristic and connected in parallel with the capacitor 7. A thermistor or the like can be applied as a resistor having a positive temperature characteristic.
【0011】配電線1の電流に対応した電荷が演算処理
部5からコンデサ7に充電される。放電抵抗18は正の
温度特性を有するので、環境温度が上昇すれば、抵抗値
が大きくなり、コンデサ7からの電荷の放出が減少す
る。このためコンデサ7の電位上昇は常温時より早くな
り、過電流による遮断時限が短くなる。逆に、環境温度
が低下すれば、放電抵抗18の抵抗値は小さくなりコン
デサ7からの電荷の放出が多くなるので、コンデサ7の
電位上昇は常温時より遅くなり、低温時は過電流による
遮断時限が長くなる。これにより、バイメタルによる電
流検出素子と同様に通電熱履歴特性を持ち環境温度時限
特性を持つ電子式過電流検出装置となる。A charge corresponding to the current of the distribution line 1 is charged from the arithmetic processing unit 5 to the capacitor 7. Since the discharge resistor 18 has a positive temperature characteristic, as the environmental temperature increases, the resistance value increases, and the discharge of electric charge from the capacitor 7 decreases. For this reason, the potential rise of the capacitor 7 becomes faster than at normal temperature, and the cutoff time due to the overcurrent is shortened. Conversely, when the environmental temperature decreases, the resistance value of the discharge resistor 18 decreases, and the discharge of electric charge from the capacitor 7 increases. Therefore, the potential rise of the capacitor 7 becomes slower than at normal temperature, and at low temperature, interruption due to overcurrent occurs. The time limit becomes longer. As a result, an electronic overcurrent detection device having an energization heat history characteristic and an environmental temperature time characteristic as in the case of the bimetallic current detection element is obtained.
【0012】実施の形態2.配線用遮断器の温度による
許容電流を決定する時限特性は外気温度に対応させるこ
とが望ましいが、上記実施の形態1の構成は放電抵抗1
8が配線用遮断器の筐体内に配設されているため、配線
用遮断器自身の温度上昇の影響を受けて、外部の環境温
度にそぐわない時限特性となることもある。該実施の形
態2はこの点を改善した構成である。Embodiment 2 FIG. It is desirable that the time characteristic for determining the allowable current depending on the temperature of the wiring breaker corresponds to the outside air temperature.
Since the wiring breaker 8 is disposed in the housing of the circuit breaker, the temperature characteristic of the circuit breaker itself may not be suitable for the external environmental temperature due to the temperature rise of the circuit breaker itself. The second embodiment has a configuration that improves this point.
【0013】図2はこの発明の実施の形態2を示す電子
式過電流検出装置のブロック図である。図において、1
〜7、9〜13、18は上記実施の形態1の説明と同様
のものである。20は配線用遮断器の筐体外部に設けら
れた筐体凹部であり、正の温度特性を有する放電抵抗1
8はこの筐体凹部20に配設されて外気に接するように
なっている。これにより、放電抵抗18は配線用遮断器
自身の温度上昇の影響を受けることなく、常に外部の環
境温度による抵抗値となるので、外気温度に対応した時
限特性とすることができる。FIG. 2 is a block diagram of an electronic overcurrent detection device according to a second embodiment of the present invention. In the figure, 1
7, 9 to 13, and 18 are the same as those described in the first embodiment. Reference numeral 20 denotes a housing recess provided outside the housing of the circuit breaker for wiring, and a discharge resistor 1 having a positive temperature characteristic.
Numeral 8 is arranged in the housing recess 20 so as to come into contact with the outside air. As a result, the discharge resistor 18 always has a resistance value based on the external environmental temperature without being affected by a rise in the temperature of the circuit breaker itself, so that it is possible to obtain a timed characteristic corresponding to the outside air temperature.
【0014】放電抵抗18が他の機器に接触したり、人
手の接触は時限特性に外気温を性格に反映できないので
筐体凹部20に配置し、さらに格子状のカバーで保護す
ることが望まれる。Since the discharge resistor 18 does not come into contact with another device or a human contact cannot accurately reflect the outside temperature in the timed characteristic, it is desirable to dispose it in the housing recess 20 and protect it with a grid-like cover. .
【0015】[0015]
【発明の効果】以上のように電子式過電流検出装置の時
限特性設定用のコンデンサ7に並列接続される放電抵抗
18を正の温度特性を有する抵抗体とすることで、電子
式過電流検出装置であってもバイメタル素子と同様の通
電熱履歴特性および環境温度時限特性を持たせ、配電線
及び負荷の過熱保護が可能となる。As described above, the discharge resistor 18 connected in parallel to the capacitor 7 for setting the time limit characteristic of the electronic overcurrent detection device is made of a resistor having a positive temperature characteristic. Even in the case of the device, the same thermal history characteristic and environmental temperature time characteristic as those of the bimetal element are provided, and the overheating protection of the distribution line and the load becomes possible.
【図1】 この発明の実施の形態1を示す電子式過電流
検出装置のブロック図である。FIG. 1 is a block diagram of an electronic overcurrent detection device according to a first embodiment of the present invention.
【図2】 この発明の実施の形態2を示す電子式過電流
検出装置のブロック図である。FIG. 2 is a block diagram of an electronic overcurrent detection device according to a second embodiment of the present invention.
【図3】 従来の電子式過電流検出装置のブロック図で
ある。FIG. 3 is a block diagram of a conventional electronic overcurrent detection device.
【図4】 配電用遮断器の温度補正を示すグラフであ
る。FIG. 4 is a graph showing a temperature correction of the distribution circuit breaker.
1 配電線、 2 開閉接点、 3 変流器 4 AC/DC変換回路、 5 演算処理部、 7
コンデンサ 8 放電抵抗、 9 ツェナーダイオード、10 コ
ンパレータ 11 引外し回路、 12 引外しコイル 18 正の温度特性の放電抵抗、 20 筐体凹部DESCRIPTION OF SYMBOLS 1 Distribution line, 2 Switching contact, 3 Current transformer 4 AC / DC conversion circuit, 5 Arithmetic processing part, 7
Capacitor 8 Discharge resistor, 9 Zener diode, 10 Comparator 11 Trip circuit, 12 Trip coil 18 Discharge resistor with positive temperature characteristic, 20 Housing recess
Claims (2)
段と、検出された電流を演算処理して電流の大きさに対
応する電荷信号にして送出する演算処理部と、上記演算
処理部からの電荷を蓄電するコンデンサと、このコンデ
ンサに並列接続された放電抵抗と、上記コンデンサの電
位と基準電圧とを比較するコンパレータとを備え、上記
コンパレータの比較において「コンデンサの電位>基準
電圧」になったとき信号出力する電子式過電流検出装置
において、上記放電抵抗を正の温度特性を有する抵抗体
としたことを特徴とする電子式過電流検出装置。1. A current detecting means for detecting a current flowing through a distribution line, an arithmetic processing unit for arithmetically processing the detected current and sending it as a charge signal corresponding to the magnitude of the current, and And a discharge resistor connected in parallel with the capacitor, and a comparator for comparing the potential of the capacitor with a reference voltage. In the comparison between the comparators, "capacitor potential> reference voltage" is obtained. An electronic overcurrent detection device that outputs a signal when the electric discharge occurs, wherein the discharge resistor is a resistor having a positive temperature characteristic.
置筐体外部の外気と接する部位に配置したことを特徴と
する請求項1に記載の電子式過電流検出装置。2. The electronic overcurrent detection device according to claim 1, wherein the discharge resistor having a positive temperature characteristic is arranged at a portion in contact with outside air outside the device housing.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2000079933A JP2001268778A (en) | 2000-03-22 | 2000-03-22 | Electronic overcurrent detection device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2000079933A JP2001268778A (en) | 2000-03-22 | 2000-03-22 | Electronic overcurrent detection device |
Publications (1)
Publication Number | Publication Date |
---|---|
JP2001268778A true JP2001268778A (en) | 2001-09-28 |
Family
ID=18597109
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP2000079933A Pending JP2001268778A (en) | 2000-03-22 | 2000-03-22 | Electronic overcurrent detection device |
Country Status (1)
Country | Link |
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JP (1) | JP2001268778A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2010021081A (en) * | 2008-07-11 | 2010-01-28 | Tokyo Electric Power Co Inc:The | Overcurrent circuit breaker, and interruption method of overcurrent |
EP2097287A4 (en) * | 2006-12-22 | 2018-03-28 | Volvo Truck Corporation | Method and arrangement for discharging an energy storage system for electrical energy |
-
2000
- 2000-03-22 JP JP2000079933A patent/JP2001268778A/en active Pending
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2097287A4 (en) * | 2006-12-22 | 2018-03-28 | Volvo Truck Corporation | Method and arrangement for discharging an energy storage system for electrical energy |
JP2010021081A (en) * | 2008-07-11 | 2010-01-28 | Tokyo Electric Power Co Inc:The | Overcurrent circuit breaker, and interruption method of overcurrent |
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