CN203616610U - Conditioning circuit in small current constant value processing - Google Patents
Conditioning circuit in small current constant value processing Download PDFInfo
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- CN203616610U CN203616610U CN201320756340.8U CN201320756340U CN203616610U CN 203616610 U CN203616610 U CN 203616610U CN 201320756340 U CN201320756340 U CN 201320756340U CN 203616610 U CN203616610 U CN 203616610U
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- operational amplifier
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Abstract
The utility model relates to the technical field of the electric power automation, and discloses a conditioning circuit in small current constant value processing. A first resistor and a second resistor are connected in parallel and are connected between a first pin and a second pin of an output end of a current transformer; the second pin of the output end of the current transformer is connected with an input in-phase end of a first operational amplifier through a third resistor; an input inverting phase end of the first operational amplifier is connected with an output end of the first operational amplifier; one end of a fourth resistor is connected with the output end of the first operational amplifier; one end of a sixth resistor is connected to the input inverting phase end of the first operational amplifier, and the other end of the sixth resistor is connected to an input in-phase end of a second operational amplifier; one end of a fifth resistor and one end of a seventh resistor are connected with an input inverting phase end of the second operational amplifier; the other end of the seventh resistor is connected to an output end of the second operational amplifier; and one end of a eighth resistor is connected with the output end of the second operational amplifier. In the utility model, two voltage signals including the protection acquisition signal and the measurement acquisition signal can be outputted.
Description
Technical field
The utility model relates to power automation technical field, in particular, and the particularly modulate circuit in a kind of little current ration processing.
Background technology
In electric automation product; line protective devices fundamental purpose is detection failure electric current; the range of current General Requirements of measuring is 20 times of rated current; and realize route protection according to protection definite value, the operating time of protection set; less demanding to measuring accuracy, the measuring accuracy in 10 times of rated current of General Requirements is in 3%.
The major function of the automatic subscriber demarcation switch in distribution automation comprises remote measurement (electric current, voltage, power measurement), remote signalling (on off state etc.), remote control (breaking-closing operating), protection etc.
In major network route protection, current protection definite value is set according to line short circuit current, and general definite value is larger, therefore not high to the accuracy requirement of protection; At particularly user's branched line of distribution line, the setting of protection definite value is set according to load capacity, and the convenience of power supply department in order to purchase and to apply, generally according to the unified configuration of the maximum load in region CT no-load voltage ratio.As: the transformer of 1 630kVA; adopt 600/5 current transformer; the rated current of transformer is 36.4A; the quick-break definite value of automatic subscriber demarcation switch is set as 50A; according to 20 times of rated current of current protective device: the measurement range of 20*600A=12000A; 50A is only equivalent to 0.4% of maximum protection value; its accuracy requirement is considerably beyond the requirement of the measuring accuracy in 10 times of rated current of protective device in 3%; therefore, easily there is the situation of misoperation in automatic subscriber demarcation switch in actual applications.Be existing protective device to user demarcation switch protection setting means in practical application deficiency.
Utility model content
It is a kind of cheaply for the modulate circuit in the little current ration processing of current protection that the purpose of this utility model is to provide.
In order to solve problem set forth above, the technical solution adopted in the utility model is: the modulate circuit in a kind of little current ration processing, it comprises current transformer, the first to the 8th resistance and first, second operational amplifier, is connected between output terminal first pin and the second pin of current transformer after described the first and second resistance are parallel with one another; Output terminal second pin of described current transformer is also connected with the input in-phase end of the first operational amplifier through the 3rd resistance, the input inversion end of described the first operational amplifier is connected with its output terminal, one end of described the 4th resistance is connected with the output terminal of the first operational amplifier, and the other end is connected with a first signal collection terminal; Described the 6th resistance one end is connected with the input inversion end of the first operational amplifier, and the other end is connected with the input in-phase end of the second operational amplifier; The described the 5th is connected with one end of the 7th resistance and the input inversion end of the second operational amplifier, the other end of described the 7th resistance is connected with the output terminal of the second operational amplifier, described the 8th resistance one end is connected with the output terminal of the second operational amplifier, and the other end is connected with a secondary signal collection terminal.
According to a preferred embodiment of the present utility model: also comprise electric capacity, one end of described electric capacity is connected with the input in-phase end of the first operational amplifier, other end ground connection.
According to a preferred embodiment of the present utility model: also comprise the A/D converter being connected with described first signal collection terminal, secondary signal collection terminal.
Compared with prior art, the beneficial effects of the utility model are: same electric current is inputted after modulate circuit of the present utility model, exportable two-way voltage signal, the i.e. voltage signal of the first and second signals collecting ends, wherein a road output is as protection collection signal, and measurement range meets the requirement of 20 times of rated current of current protection; Another road output is as measuring collection signal, and measurement range meets the requirement of 1.2 times of rated current.
Accompanying drawing explanation
Fig. 1 is the circuit diagram of the modulate circuit during little current ration of the present utility model is processed.
Embodiment
Below in conjunction with embodiment and accompanying drawing, the utility model is described in further detail, but embodiment of the present utility model is not limited to this.
Consult shown in Fig. 1, the utility model provides the modulate circuit in a kind of little current ration processing, it comprises Current Transmit 1, the first to the 8th resistance (R1-R8) and first, second operational amplifier (U1, U2), after the first and second resistance (R1, R2) are parallel with one another, be connected between output terminal first pin and the second pin of Current Transmit 1; Output terminal second pin of Current Transmit 1 is also connected with the input in-phase end of the first operational amplifier U1 through the 3rd resistance R 3, the input inversion end of the first operational amplifier U1 is connected with its output terminal, one end of the 4th resistance R 4 is connected with the output terminal of the first operational amplifier U1, and the other end is connected with a first signal collection terminal; The 6th resistance R 6 one end are connected with the input inversion end of the first operational amplifier U1, and the other end is connected with the input in-phase end of the second operational amplifier U2; The the 5th and the 7th resistance (R5, R7) one end is connected with the input inversion end of the second operational amplifier U2, the other end of the 7th resistance R 7 is connected with the output terminal of the second operational amplifier U2, the 8th resistance R 8 one end are connected with the output terminal of the second operational amplifier U2, and the other end is connected with a secondary signal collection terminal.And the utility model also comprises capacitor C 1, one end of capacitor C 1 is connected with the input in-phase end of the first operational amplifier U1, other end ground connection.And also comprise the A/D converter being connected with first signal collection terminal, secondary signal collection terminal, for gathering the two-way voltage signal of first signal collection terminal, secondary signal collection terminal, wherein the output of Yi road is as protection collection signal AIN2, and measurement range meets the requirement of 20 times of rated current of current protection; Another road output is as measuring collection signal AIN6, and measurement range meets the requirement of 1.2 times of rated current.
The utility model also can increase control chip after A/D converter to be processed; simultaneously according to protection collection signal AIN2 and measurement collection signal AIN6 judgement protection action; when line current is hour by measuring collection signal AIN6 judgement protection action, in the time that line current is larger by protection collection signal AIN2 judgement protection action.Both guaranteed the precision of protection judgement, the reliability of protection judgement while greatly having improved little current protection definite value again.
Specific works principle of the present utility model is: input current is exported again through the first and second resistance (R1 through Current Transmit 1, R2) sampling, obtain the voltage signal of 0-5V, the follower output protection collection signal AIN2 forming through the first operational amplifier U1 again, protection collection signal AIN2 is protection sampled signal, measurement range is 0-100A, and measuring accuracy when 10 times of rated current (50A) is 3%; Collection signal AIN6 is measured in protection collection signal AIN2 output after the amplifying circuit of the second operational amplifier U1 composition, measures collection signal AIN6 and is measurement sampled signal, and the scope of measurement is 0-6A, and measuring accuracy is 0.5%.And control chip can gather protection collection signal AIN2 and measure collection signal AIN6 simultaneously, in the time that protection collection signal AIN2 measured value is below certain current value (being set as at present 4A), judge protection action according to measuring collection signal AIN6; In the time that protection collection signal AIN2 measured value is greater than certain current value (being set as at present 4A), judge protection action according to protective number collection signal AIN2.
Above-described embodiment is preferably embodiment of the utility model; but embodiment of the present utility model is not restricted to the described embodiments; other any do not deviate from change, the modification done under Spirit Essence of the present utility model and principle, substitutes, combination, simplify; all should be equivalent substitute mode, within being included in protection domain of the present utility model.
Claims (3)
1. the modulate circuit in one kind little current ration processing, it is characterized in that: comprise current transformer (CT1), the first to the 8th resistance (R1-R8) and first, second operational amplifier (U1, U2), after described the first and second resistance (R1, R2) are parallel with one another, be connected between output terminal first pin and the second pin of current transformer (CT1); Output terminal second pin of described current transformer (CT1) is also connected with the input in-phase end of the first operational amplifier (U1) through the 3rd resistance (R3), the input inversion end of described the first operational amplifier (U1) is connected with its output terminal, one end of described the 4th resistance (R4) is connected with the output terminal of the first operational amplifier (U1), and the other end is connected with a first signal collection terminal; Described the 6th resistance (R6) one end is connected with the input inversion end of the first operational amplifier (U1), and the other end is connected with the input in-phase end of the second operational amplifier (U2); The the described the 5th and the 7th resistance (R5, R7) one end is connected with the input inversion end of the second operational amplifier (U2), the other end of described the 7th resistance (R7) is connected with the output terminal of the second operational amplifier (U2), described the 8th resistance (R8) one end is connected with the output terminal of the second operational amplifier (U2), and the other end is connected with a secondary signal collection terminal.
2. the modulate circuit in little current ration processing according to claim 1, is characterized in that: also comprise electric capacity (C1), one end of described electric capacity (C1) is connected with the input in-phase end of the first operational amplifier (U1), other end ground connection.
3. the modulate circuit in little current ration processing according to claim 1, is characterized in that: also comprise the A/D converter being connected with described first signal collection terminal, secondary signal collection terminal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320756340.8U CN203616610U (en) | 2013-11-25 | 2013-11-25 | Conditioning circuit in small current constant value processing |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320756340.8U CN203616610U (en) | 2013-11-25 | 2013-11-25 | Conditioning circuit in small current constant value processing |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203616610U true CN203616610U (en) | 2014-05-28 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201320756340.8U Expired - Fee Related CN203616610U (en) | 2013-11-25 | 2013-11-25 | Conditioning circuit in small current constant value processing |
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| Country | Link |
|---|---|
| CN (1) | CN203616610U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107733384A (en) * | 2017-11-21 | 2018-02-23 | 雷顿电气科技有限公司 | Folk art term bit arithmetic amplifier circuit |
-
2013
- 2013-11-25 CN CN201320756340.8U patent/CN203616610U/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107733384A (en) * | 2017-11-21 | 2018-02-23 | 雷顿电气科技有限公司 | Folk art term bit arithmetic amplifier circuit |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C56 | Change in the name or address of the patentee |
Owner name: NANJING HAIXING YUANWEI DISTRIBUTION AUTOMATION CO Free format text: FORMER NAME: NANJING YUANWEI ELECTRIC POWER AUTOMATION CO., LTD. |
|
| CP01 | Change in the name or title of a patent holder |
Address after: 211153, No. 100, general road, Jiangning economic and Technological Development Zone, Nanjing, Jiangsu Patentee after: Nanjing Haixing far Dimensional Distribution Automation Co. Address before: 211153, No. 100, general road, Jiangning economic and Technological Development Zone, Nanjing, Jiangsu Patentee before: WISCOM ELECTRIC POWER AUTOMATION CO., LTD. |
|
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20140528 Termination date: 20161125 |