CN204314413U - A kind of cable short circuit detecting device - Google Patents
A kind of cable short circuit detecting device Download PDFInfo
- Publication number
- CN204314413U CN204314413U CN201420861084.3U CN201420861084U CN204314413U CN 204314413 U CN204314413 U CN 204314413U CN 201420861084 U CN201420861084 U CN 201420861084U CN 204314413 U CN204314413 U CN 204314413U
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- current
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- conversion circuit
- current conversion
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Abstract
The utility model discloses a kind of cable short circuit detecting device, comprise short trouble capture circuit, the testing circuit with the parallel connection of short trouble capture circuit, the microprocessor be connected with short trouble capture circuit and testing circuit and the communication module be connected with microprocessor; The utility model meets separately the high-precision requirement of current detecting by a special current conversion circuit, the requirement that electric current falls high-speed response is met separately by another special current conversion circuit, avoid compromise choose rectified current capacitance and cause the shortcoming that accuracy of detection is low, rate of false alarm is high, there is higher precision and lower rate of false alarm; Utilize current-voltage conversion element that the input current of cable is transformed into voltage, compare the voltage and reference voltage that were transformed, and export the output signal of its magnitude relationship corresponding; There is higher stability.
Description
Technical field
The utility model relates to cable detection technical field, is specially a kind of cable short circuit detecting device.
Background technology
Realize in existing distribution automation system whether being short-circuited the Real-time Collection of fault and the network distribution device mainly fault detector of monitoring to pole line, underground cable, fault detector is the device of curent change on a kind of energy monitoring cable, when be short-circuited fault time, fault detector can catch the generation of short circuit event, and by various means of communication notice monitoring personnel.
Fig. 1 shows a kind of structure of existing fault detector, and described fault detector mainly comprises current conversion circuit 1 ', microprocessor 2 ' and communication module 3 '.Described current conversion circuit 1 ' comprises current transformer 11, divider resistance 12, rectifier bridge 13 and commutation capacitor 14 further, and they complete jointly by the conversion of the AC great current signal on power cable to direct current small voltage signal 15.Direct current small voltage signal 15 analog to digital converter entered in microprocessor 2 ' after conversion is converted to digital signal, microprocessor 2 ' is by the storage of digital signal and computing, judge the fault that whether is short-circuited, then spread out of to external unit by communication module 3 '.There is following problem in actual applications in this fault detector: when the capacity of commutation capacitor 14 is chosen larger, and the ripple of direct current small voltage signal 15 is little, and current detection accuracy is high, but cannot reflect falling rapidly of electric current in time; When commutation capacitor 14 choose capacity less time, although can reflect falling rapidly of electric current in time, the ripple of direct current small voltage signal 15 is large, and current detection accuracy is low.Due to fault detector detect the Main Basis of short trouble be current value and electric current fall response, therefore the scheme choosing general employing compromise of commutation capacitor 14, to take into account current precision and to fall rate request simultaneously, also this two indices can be caused thus all very common, the requirement of high precision and high-speed response cannot be met; And can not be clear and definite measure short circuit time this two indices, further judgement can not be made.
Utility model content
The purpose of this utility model is to provide a kind of cable short circuit detecting device, to solve the problem proposed in above-mentioned background technology.
For achieving the above object, the utility model provides following technical scheme:
A kind of cable short circuit detecting device, comprises short trouble capture circuit, the testing circuit with the parallel connection of short trouble capture circuit, the microprocessor be connected with short trouble capture circuit and testing circuit and the communication module be connected with microprocessor; Described short trouble capture circuit comprises: the first current conversion circuit, and the second current conversion circuit, and described first current conversion circuit is in parallel with the first current conversion circuit; Described first current conversion circuit comprises the first current transformer, the first divider resistance, the first rectifier bridge and the first commutation capacitor that are electrically connected successively, and described first current conversion circuit provides the first small voltage signal; Described second current conversion circuit comprises the second current transformer, the second divider resistance, the second rectifier bridge and the second commutation capacitor that are electrically connected successively, and described second current conversion circuit provides the second small voltage signal; Described testing circuit comprises voltage comparator, voltage comparator electrode input end is linked between the first current transformer and the first divider resistance, voltage comparator negative input is connected between the second current transformer and the second divider resistance by reference voltage generating circuit, current-voltage conversion element, and the output terminal of voltage comparator is connected with microprocessor.
Further, it is relatively slow that the electric current of described first current conversion circuit falls response, and the first small voltage signal is comparatively accurate; The electric current of described second current conversion circuit falls response relatively comparatively fast, and the second small voltage signal is comparatively coarse.
Further, the capacitance of described second commutation capacitor is less than the capacitance of described first commutation capacitor.
Further, described reference voltage generating circuit comprises metal-oxide-semiconductor field effect transistor Q1 ~ Q3, the drain electrode of metal-oxide-semiconductor field effect transistor Q1 connects voltage, source electrode connects the drain electrode of effect pipe Q3, grid connects the grid of effect pipe Q2 and the drain electrode of effect pipe Q3 respectively, the drain electrode of metal-oxide-semiconductor field effect transistor Q2 connects voltage, and source electrode connects divider resistance R11 and R12, and the grid of metal-oxide-semiconductor field effect transistor Q3 is also connected with the source electrode of effect pipe Q2.
Compared with prior art, the utility model meets separately the high-precision requirement of current detecting by a special current conversion circuit, the requirement that electric current falls high-speed response is met separately by another special current conversion circuit, avoid compromise choose rectified current capacitance and cause the shortcoming that accuracy of detection is low, rate of false alarm is high, there is higher precision and lower rate of false alarm; Utilize current-voltage conversion element that the input current of cable is transformed into voltage, compare the voltage and reference voltage that were transformed, and export the output signal of its magnitude relationship corresponding; There is higher stability.
Accompanying drawing explanation
Fig. 1 is the structural representation of the short trouble capture circuit of existing power cable.
Fig. 2 is the structural representation of a kind of cable short circuit detecting device of the utility model.
Fig. 3 is the schematic diagram of reference voltage generating circuit in a kind of cable short circuit detecting device of the utility model.
Embodiment
Be described in more detail below in conjunction with the technical scheme of embodiment to this patent.
Refer to Fig. 2 ~ 3, a kind of cable short circuit detecting device, comprises short trouble capture circuit, the testing circuit with the parallel connection of short trouble capture circuit, the microprocessor be connected with short trouble capture circuit and testing circuit and the communication module be connected with microprocessor; Described short trouble capture circuit comprises: the first current conversion circuit 1a, in order to the big current signal of the interchange on a power cable to be converted to the first small voltage signal 15a of direct current; And the second current conversion circuit 1b, in order to the big current signal of the interchange on described power cable to be converted to the second small voltage signal 15b of direct current, described first current conversion circuit is in parallel with the first current conversion circuit; Wherein, the electric current of described second current conversion circuit 1b falls response and falls from the electric current of described first current conversion circuit 1a that to respond be different; Short trouble capture circuit 1 falls response different small voltage signal 15a, 15b by the big current signal of the interchange on a power cable to be converted to two-way electric current simultaneously, can be combined flexibly with the fault judging circuit such as follow-up microprocessor, meet the requirement of high precision that short trouble detects and high-speed response simultaneously.
Particularly, it is relatively slow that the electric current of described first current conversion circuit 1a falls response, and described first small voltage signal 15a is comparatively accurate; The electric current of described second current conversion circuit 1b falls response relatively comparatively fast, and described second small voltage signal 15b is comparatively coarse.Therefore the first current conversion circuit 1a can be used for being responsible for specially and meets high-precision requirement, described second current conversion circuit 1b can be used for being responsible for meeting the requirement of high-speed response.
In the present embodiment, described first current conversion circuit 1a comprises the first current transformer 11a, the first divider resistance 12a, the first rectifier bridge 13a and the first commutation capacitor 14a that are electrically connected successively, and described first current conversion circuit 1a provides the first small voltage signal 15a; Described second current conversion circuit 1b comprises the second current transformer 11b, the second divider resistance 12b, the second rectifier bridge 13b and the second commutation capacitor 14b that are electrically connected successively, and described second current conversion circuit 1b provides the second small voltage signal 15b.
Wherein, the capacitance of described second commutation capacitor 14b is less than the capacitance of described first commutation capacitor 14a.This structure, as long as the capacitance of carrying out commutation capacitor 14a, 14b is simply chosen, can make the electric current of described second current conversion circuit 1b fall response from the electric current of described first current conversion circuit 1a fall respond different.
Described testing circuit comprises voltage comparator, voltage comparator electrode input end is linked between the first current transformer 11a and the first divider resistance 12a, voltage comparator negative input is connected between the second current transformer 11b and the second divider resistance 12b by reference voltage generating circuit, current-voltage conversion element, and the output terminal of voltage comparator is connected with microprocessor; Described reference voltage generating circuit comprises metal-oxide-semiconductor field effect transistor Q1 ~ Q3, the drain electrode of metal-oxide-semiconductor field effect transistor Q1 connects voltage vcc, source electrode connects the drain electrode of effect pipe Q3, grid connects the grid of effect pipe Q2 and the drain electrode of effect pipe Q3 respectively, the drain electrode of metal-oxide-semiconductor field effect transistor Q2 connects voltage vcc, source electrode connects divider resistance R11 and R12, and the grid of metal-oxide-semiconductor field effect transistor Q3 is also connected with the source electrode of effect pipe Q2.
During utility model works, by current-voltage conversion element, the input current of cable is transformed into voltage, then transformed voltage and reference voltage is compared by voltage comparator, voltage comparator output terminal exports judged result to microprocessor; And short trouble capture circuit is in order to be converted to the small voltage signal of direct current by the big current signal of the interchange on a power cable, microprocessor is in order to judge short trouble according to this small voltage signal, and communication module exists in order to the judged result external device report short trouble according to this microprocessor.
Above the better embodiment of this patent is explained in detail, but this patent is not limited to above-mentioned embodiment, in the ken that one skilled in the relevant art possesses, various change can also be made under the prerequisite not departing from this patent aim.
Claims (4)
1. a cable short circuit detecting device, it is characterized in that, comprise short trouble capture circuit, the testing circuit with the parallel connection of short trouble capture circuit, the microprocessor be connected with short trouble capture circuit and testing circuit and the communication module be connected with microprocessor; Described short trouble capture circuit comprises: the first current conversion circuit, and the second current conversion circuit, and described first current conversion circuit is in parallel with the first current conversion circuit; Described first current conversion circuit comprises the first current transformer, the first divider resistance, the first rectifier bridge and the first commutation capacitor that are electrically connected successively, and described first current conversion circuit provides the first small voltage signal; Described second current conversion circuit comprises the second current transformer, the second divider resistance, the second rectifier bridge and the second commutation capacitor that are electrically connected successively, and described second current conversion circuit provides the second small voltage signal; Described testing circuit comprises voltage comparator, voltage comparator electrode input end is linked between the first current transformer and the first divider resistance, voltage comparator negative input is connected between the second current transformer and the second divider resistance by reference voltage generating circuit, current-voltage conversion element, and the output terminal of voltage comparator is connected with microprocessor.
2. a kind of cable short circuit detecting device according to claim 1, is characterized in that, it is relatively slow that the electric current of described first current conversion circuit falls response, and the first small voltage signal is comparatively accurate; The electric current of described second current conversion circuit falls response relatively comparatively fast, and the second small voltage signal is comparatively coarse.
3. a kind of cable short circuit detecting device according to claim 1, is characterized in that, the capacitance of described second commutation capacitor is less than the capacitance of described first commutation capacitor.
4. a kind of cable short circuit detecting device according to claim 1, it is characterized in that, described reference voltage generating circuit comprises metal-oxide-semiconductor field effect transistor Q1 ~ Q3, the drain electrode of metal-oxide-semiconductor field effect transistor Q1 connects voltage, source electrode connects the drain electrode of effect pipe Q3, and grid connects the grid of effect pipe Q2 and the drain electrode of effect pipe Q3 respectively, and the drain electrode of metal-oxide-semiconductor field effect transistor Q2 connects voltage, source electrode connects divider resistance R11 and R12, and the grid of metal-oxide-semiconductor field effect transistor Q3 is also connected with the source electrode of effect pipe Q2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420861084.3U CN204314413U (en) | 2014-12-31 | 2014-12-31 | A kind of cable short circuit detecting device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420861084.3U CN204314413U (en) | 2014-12-31 | 2014-12-31 | A kind of cable short circuit detecting device |
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| Publication Number | Publication Date |
|---|---|
| CN204314413U true CN204314413U (en) | 2015-05-06 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201420861084.3U Expired - Fee Related CN204314413U (en) | 2014-12-31 | 2014-12-31 | A kind of cable short circuit detecting device |
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| Country | Link |
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| CN (1) | CN204314413U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108469568A (en) * | 2018-06-26 | 2018-08-31 | 桂林电子科技大学 | A kind of detection alarm device and application that oscilloprobe earth clip is short-circuit with circuit board touching |
| CN109031064A (en) * | 2018-07-24 | 2018-12-18 | 常州同惠电子股份有限公司 | High pressure two for wire test instrument divides test method |
-
2014
- 2014-12-31 CN CN201420861084.3U patent/CN204314413U/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108469568A (en) * | 2018-06-26 | 2018-08-31 | 桂林电子科技大学 | A kind of detection alarm device and application that oscilloprobe earth clip is short-circuit with circuit board touching |
| CN109031064A (en) * | 2018-07-24 | 2018-12-18 | 常州同惠电子股份有限公司 | High pressure two for wire test instrument divides test method |
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Legal Events
| Date | Code | Title | Description |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20150506 Termination date: 20151231 |
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| EXPY | Termination of patent right or utility model |