CN203981735U - Variable specific current transformer self-checking device - Google Patents
Variable specific current transformer self-checking device Download PDFInfo
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- CN203981735U CN203981735U CN201420293450.XU CN201420293450U CN203981735U CN 203981735 U CN203981735 U CN 203981735U CN 201420293450 U CN201420293450 U CN 201420293450U CN 203981735 U CN203981735 U CN 203981735U
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- 238000004804 winding Methods 0.000 claims description 12
- 238000000034 method Methods 0.000 description 5
- 238000012360 testing method Methods 0.000 description 3
- 230000005611 electricity Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
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Abstract
The utility model provides variable specific current transformer self-checking device, between variable specific current transformer and metering electric energy meter, comprise electric current determination module and metering modular converter, the quiescent current relay that described electric current determination module comprises sampling current transformer and is attached thereto, described metering modular converter comprises metering current mulual inductor and auxiliary reclay, described electric current determination module is connected with the primary side of described variable specific current transformer, and described metering modular converter is connected with described metering electric energy meter.The utility model can be realized when underload, overload, current transformer measuring accuracy does not reduce, without manually adjusting CT no-load voltage ratio, there is very high practical value, precision digital element that need not complex and expensive, just can effectively improve power supply measuring accuracy, reduce electric quantity loss, improve the economic benefit of electric power enterprise.
Description
Technical field
The utility model relates to parameters of electric power and regulates control technology field, relates in particular to variable specific current transformer self-checking device.
Background technology
Electric energy metrical is the important component part of electrical network economy, stable operation, is the important step that electrical production is sold.The accuracy of electric energy metrical, reliability are subject to the consistent attention of power supply enterprise, particularly in County Power Plant, and the feature such as rural power service circuit ubiquity load variations is large, and seaonal load is obvious, and daily load peak-valley difference is large.
Because above-mentioned reason, current transformer for metering just often easily occurs that actual loading rate surpasses 120% or lower than 20% extreme case, both of these case there will be metering " dead angle ".Existing " S " level current transformer generally can be accomplished the double winding of two kinds of multiplying powers, but when load variations, need manually to adjust no-load voltage ratio, calculate respectively electric degree, cause frequent power failure, to user, bring great economic loss and inconvenience, the electricity bill control clearing of Ye Gei power supply enterprise have brought compared with burden.
Application number is that 201320728799.7 patent discloses a kind of current transformer self-checking device, comprise controller and the current collector and the servo-driver that are connected with described controller, described current collector is connected with the current transformer in secondary circuit, described servo-driver is connected with control motor, and described control motor is connected with the shunting switch of current transformer in described secondary circuit by topworks.By current collector, gather the strength of current value in secondary circuit, be sent to controller, in controller, collection value and settings compare, when collection value reaches setting value, controller makes to control motor action by controlling servo-driver, controlling driven by motor topworks switches shunting switch, reach the gear of appointment, make Current Transformer Secondary electric current within the limits prescribed, reach accurate measurement and reliable object, but, the realization of this device need to increase servomotor and the digitial controller for relatively judging, not only strengthened load, and increased cost, also be unfavorable for normal production and operation.
Utility model content
The utility model provides variable specific current transformer self-checking device, and can guarantee, under little electric current and overload condition, does not need the wiring of Manual Switch current transformer, just can realize no-load voltage ratio automatically switches, increase security, improved reliability, reduced labour intensity.
For achieving the above object, technical solution adopted in the utility model is: variable specific current transformer self-checking device, between variable specific current transformer and metering electric energy meter, comprise electric current determination module and metering modular converter, the quiescent current relay that described electric current determination module comprises sampling current transformer and is attached thereto, described metering modular converter comprises metering current mulual inductor and auxiliary reclay, described electric current determination module is connected with the primary side of described variable specific current transformer, and described metering modular converter is connected with described metering electric energy meter.
Described quiescent current relay comprises one group of normally closed node K11, and described normally closed node K11 is connected with auxiliary reclay.
Described normally closed node K11 and described auxiliary reclay are all arranged in independent ac control circuit.
Described auxiliary reclay comprises that one group of normally closed node K21 and two groups often open node K22, K23, described normally closed node K21 is between described variable specific current transformer secondary side winding and described metering electric energy meter, described normal opened contact K22 one end connects described variable specific current transformer secondary side, the other end connects described metering current mulual inductor primary side, described normal opened contact K23 one end connects described metering current mulual inductor secondary side, and the other end connects described metering electric energy meter.
The implementation method of this device comprises the steps:
1) primary side current of supply line is introduced respectively to the primary side of sampling current transformer and variable specific current transformer, by the secondary side of metering current mulual inductor, normally closed node K21, often open the corresponding input end that node K23 is connected to electric energy meter;
2) normally closed node K11 and auxiliary reclay are introduced to independent ac control circuit;
3) secondary side of sampling current transformer is connected to quiescent current relay, and set the working value of quiescent current relay, be generally rated current and surpass 120% or action lower than 20% time;
4) when quiescent current relay does not move, its normally closed node K11 is closed, the auxiliary reclay being connected with K11 is failure to actuate, thereby normally closed node K21 is failure to actuate, each loop connection status remains unchanged, thereby make variable specific current transformer keep large winding no-load voltage ratio, the comprehensive no-load voltage ratio of current transformer remains unchanged;
5) when there is action in quiescent current relay, its normally closed node K11 disconnects, the auxiliary reclay action being connected with K11, thereby normally closed node K21 disconnects, often open node K22, K23 closed, variable specific current transformer is switched to little winding no-load voltage ratio automatically, but because metering current mulual inductor is introduced into loop works, thereby the comprehensive no-load voltage ratio of current transformer still can be remained unchanged, reach adjusting object.
In the utility model for variable specific current transformer, it is the double winding type that comprises two kinds of multiplying powers, according to the size of multiplying power, can be divided into large winding and little winding, its no-load voltage ratio can be respectively K and K/n (n is greater than 1), and wherein normally closed node K21 connects the large winding terminal of variable specific current transformer secondary side, often opens the little winding terminal that node K22 connects variable specific current transformer secondary side, constant for guaranteeing comprehensive no-load voltage ratio, the no-load voltage ratio of metering current mulual inductor just needs to be taken as n.
About choosing of sampling current transformer; the required current capacity of quiescent current relay connecting due to its secondary side is very little; be generally less than 1VA; so; sampling current transformer not only can adopt independent current transformer; realize isolation sampling; also can directly utilize the protection carrying in the network system residue coil of mutual inductor; namely quiescent current relay is directly connected to the secondary side of protective current transformer; jointly use with other equipment, can also directly adopt the secondary coil of variable specific current transformer.In a word, its objective is the current status into acquisition system primary side, can select flexibly according to field condition.
The utility model provides a kind of variable specific current transformer self-checking device, realizes when underload, overload, and current transformer measuring accuracy does not reduce, without manually adjusting CT no-load voltage ratio.This device and method has very high practical value, and precision digital element that need not complex and expensive, just can effectively improve power supply measuring accuracy, reduces electric quantity loss, improves the economic benefit of electric power enterprise.
Accompanying drawing explanation
Fig. 1 is the structural representation of the utility model device.
Fig. 2 is the utility model installation method schematic diagram.
embodiment
As shown in Figure 1 and Figure 2, variable specific current transformer self-checking device, between variable specific current transformer 1 and metering electric energy meter 2, comprise electric current determination module 3 and metering modular converter 4, the quiescent current relay 6 that electric current determination module 3 comprises sampling current transformer 5 and is attached thereto, metering modular converter 4 comprises metering current mulual inductor 7 and auxiliary reclay 8, electric current determination module 3 is connected with the primary side of variable specific current transformer 1, and metering modular converter 4 is connected with metering electric energy meter 2.
In Method And Principle figure, I1 is primary side current, TA1 is variable specific current transformer, TA2 is metering current mulual inductor, TA3 is sampling current transformer, K11 is the normally closed node of quiescent current relay K 1, normally closed node K11 is connected with auxiliary reclay K2, normally closed node K11 and auxiliary reclay K2 are all arranged in independent ac control circuit, K21 is the normally closed node of relay K 2, K22, K23 be relay K 2 often open node, normally closed node K21 is between variable specific current transformer secondary side winding and metering electric energy meter, normal opened contact K22 one end connects variable specific current transformer secondary side, the other end connects metering current mulual inductor primary side, normal opened contact K23 one end connects metering current mulual inductor secondary side, the other end connects metering electric energy meter.
In embodiment, the large velocity ratio that can choose TA1 is K, and little no-load voltage ratio is K/5, and n is 5, and the no-load voltage ratio of TA2 also should be chosen as 5 so, i.e. 5A/1A.The primary side current of Xian Jiang supply line is introduced respectively the primary side of sampling current transformer and variable specific current transformer, by the secondary side of metering current mulual inductor, normally closed node K21, often open the corresponding input end that node K23 is connected to electric energy meter; Normally closed node K11 and auxiliary reclay are introduced to independent ac control circuit; The secondary side of sampling current transformer is connected to quiescent current relay, and set the working value of quiescent current relay, be generally rated current and surpass 120% or action lower than 20% time.
In system electric current be greater than rated current 20% and be less than rated current 120% time, current relay K1 action, normally closed node K11 disconnects, K2 auxiliary reclay dead electricity, and K21 is closed so, K22 and K23 disconnect, TA1 large velocity ratio secondary coil work like this, directly accesses electric energy meter, and each loop connection status remains unchanged, thereby variable specific current transformer keeps large winding no-load voltage ratio, the mutual inductor ratio being linked in electric energy meter is K.
When electric current be less than rated current 20% or be greater than rated current 120% time, current relay K1 returns, its normally closed node K11 is closed, relay K 2 obtains electric, and K21 disconnects so, and K22 and K23 are closed, the little no-load voltage ratio mutual inductor work of TA1 like this, through mutual inductor TA2 access electric energy meter, carry out gage work, now the comprehensive no-load voltage ratio of current transformer is that TA1 work no-load voltage ratio is the product of K/5 and current transformer TA2 no-load voltage ratio, and the comprehensive no-load voltage ratio of mutual inductor of its access electric energy meter is still K.Like this, when the utility model device makes system works, between large velocity ratio and little no-load voltage ratio, conversion all adopts same electric energy meter to measure, and pilot process has also been avoided artificial replacing metering coil and electric energy meter.
The variable specific current transformer place system that the utility model proposes also can guarantee accuracy of measurement, and verify by test within the scope of 1% to 120% wide load current.Points for attention in operation practice are summed up simultaneously.TA2 is chosen for the little transformation ratio current transformer of the little electric current of low pressure, and its accuracy can accomplish to be not less than 0.2S level, and TA1 also generally adopts 0.2S level mutual inductor in practice.At system power, be between rated current 20%-120% during no-load voltage ratio, the limit of error of its working current mutual inductor is the TA1 large velocity ratio coil limit of error, as shown below:
When system loading electric current is worked between rated current 1% to 20%, the little no-load voltage ratio current coil summation current transformer TA2 work in TA1, the limit of error sum that composition error is now for both, as shown below:
From above inference, under 20% following underload, there are laws to abide by for the accuracy of measuring, guaranteed measuring accuracy.
In order to verify the correctness of derivative inference, can select TA1 current transformer large velocity ratio is 200/5, and little no-load voltage ratio is 40/5, and class of accuracy is 0.2S level, and carrying load ability is 10VA.TA2 is the current transformer of 5A/1A, and accuracy is 0.1 grade, and carrying load ability is 10VA.Quiescent current actuating of relay current value is set as 40A.Still according to the mode of connection shown in Fig. 2, set up metering system, and the mutual inductor composition error of access electric energy meter is tested.Testing equipment is HZDT-3A full-automatic mutual inductor error testing platform, and standard is the 0.02S level current transformer with up-flow.Its experimental result is as shown below:
Metering components and parts in the utility model relate generally to table meter, secondary circuit, voltage transformer (VT), current transformer etc., wherein any requirement that all should reach DL-488 measuring apparatus verification rules, otherwise will directly affect the accuracy of measuring.
Claims (4)
1. variable specific current transformer self-checking device, between variable specific current transformer and metering electric energy meter, it is characterized in that: comprise electric current determination module and metering modular converter, the quiescent current relay that described electric current determination module comprises sampling current transformer and is attached thereto, described metering modular converter comprises metering current mulual inductor and auxiliary reclay, described electric current determination module is connected with the primary side of described variable specific current transformer, and described metering modular converter is connected with described metering electric energy meter.
2. variable specific current transformer self-checking device as claimed in claim 1, is characterized in that: described quiescent current relay comprises one group of normally closed node K11, and described normally closed node K11 is connected with auxiliary reclay.
3. variable specific current transformer self-checking device as claimed in claim 2, is characterized in that: described normally closed node K11 and described auxiliary reclay are all arranged in independent ac control circuit.
4. variable specific current transformer self-checking device as claimed in claim 1, it is characterized in that: described auxiliary reclay comprises that one group of normally closed node K21 and two groups often open node K22, K23, described normally closed node K21 is between described variable specific current transformer secondary side winding and described metering electric energy meter, described normal opened contact K22 one end connects described variable specific current transformer secondary side, the other end connects described metering current mulual inductor primary side, described normal opened contact K23 one end connects described metering current mulual inductor secondary side, the other end connects described metering electric energy meter.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420293450.XU CN203981735U (en) | 2014-06-04 | 2014-06-04 | Variable specific current transformer self-checking device |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420293450.XU CN203981735U (en) | 2014-06-04 | 2014-06-04 | Variable specific current transformer self-checking device |
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| CN203981735U true CN203981735U (en) | 2014-12-03 |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103995165A (en) * | 2014-06-04 | 2014-08-20 | 国网河南省电力公司南阳供电公司 | Automatic adjusting device and adjusting method for multi-transformation ratio current transformer |
| CN105006358A (en) * | 2015-06-29 | 2015-10-28 | 国网山东省电力公司淄博供电公司 | Current transformer |
| CN106501761A (en) * | 2016-12-26 | 2017-03-15 | 烟台东方威思顿电气股份有限公司 | Three-phase intelligent electric-energy meter simulation detection system |
-
2014
- 2014-06-04 CN CN201420293450.XU patent/CN203981735U/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103995165A (en) * | 2014-06-04 | 2014-08-20 | 国网河南省电力公司南阳供电公司 | Automatic adjusting device and adjusting method for multi-transformation ratio current transformer |
| CN105006358A (en) * | 2015-06-29 | 2015-10-28 | 国网山东省电力公司淄博供电公司 | Current transformer |
| CN106501761A (en) * | 2016-12-26 | 2017-03-15 | 烟台东方威思顿电气股份有限公司 | Three-phase intelligent electric-energy meter simulation detection system |
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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: 20141203 Termination date: 20150604 |
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| EXPY | Termination of patent right or utility model |