CN1581382A - Metering type electromagnetic current mutual inductor redidual magnetism inhibiting method - Google Patents
Metering type electromagnetic current mutual inductor redidual magnetism inhibiting method Download PDFInfo
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- CN1581382A CN1581382A CN 200410042701 CN200410042701A CN1581382A CN 1581382 A CN1581382 A CN 1581382A CN 200410042701 CN200410042701 CN 200410042701 CN 200410042701 A CN200410042701 A CN 200410042701A CN 1581382 A CN1581382 A CN 1581382A
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- current
- remanent magnetism
- current transformer
- restraining device
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- 230000005389 magnetism Effects 0.000 title claims abstract description 40
- 238000000034 method Methods 0.000 title claims abstract description 15
- 230000002401 inhibitory effect Effects 0.000 title 1
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 8
- 230000004907 flux Effects 0.000 claims abstract description 7
- 230000005291 magnetic effect Effects 0.000 claims abstract description 6
- 230000000452 restraining effect Effects 0.000 claims description 17
- 230000005764 inhibitory process Effects 0.000 claims description 8
- 229910044991 metal oxide Inorganic materials 0.000 claims description 4
- 150000004706 metal oxides Chemical class 0.000 claims description 4
- 230000000087 stabilizing effect Effects 0.000 claims description 4
- 230000001052 transient effect Effects 0.000 claims description 4
- 238000005259 measurement Methods 0.000 description 4
- 239000003302 ferromagnetic material Substances 0.000 description 3
- 239000002178 crystalline material Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 229910000889 permalloy Inorganic materials 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 230000009931 harmful effect Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
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- Measuring Instrument Details And Bridges, And Automatic Balancing Devices (AREA)
- Transformers For Measuring Instruments (AREA)
Abstract
In the method, residual magnetism restraint device is connected in parallel between secondary side of current transformer and load. Output voltage from secondary side of current transformer is restricted to preset level. Thus, magnetic flux in iron core is restricted, and is not able to be raised greatly. After current stopped, remanence in iron core is restricted, and is not able to be raised greatly, and error of the current transformer can also not be raised greatly. Features are: no complex testing and controlling circuit, simple and efficiency, high reliability, low price etc. The invention has no obvious influence on structure and operation of original current transformer.
Description
Technical field
The invention belongs to instrument transformer manufacturing technology scope, particularly a kind of amount meter type electromagnetic current transducer remanent magnetism inhibition method.
Background technology
Amount meter type electromagnetic current transducer is used for the current measurement, electric energy metrical of electric power system etc., and its accuracy is significant, and the running of electricity market is played an important role.The accuracy of now industrial amount meter type current transformer has reached 0.2 grade.Wang Xiaoqi, Guo Keqin, Yao Min, time dawn. document " remanent magnetism is to the influence of current transformer class of accuracy. 1996 06 phases of transformer; 5～9 " report: when electric power system is short-circuited fault, to produce big remanent magnetism in the current transformer, amplitude error is reached more than 0.4%, seriously surpass the nominal error scope.Proposition is made current transformer more than 0.2 grade with little non-crystalline material of coercive force and permalloy, but cost will be multiplied.Report in document " Bruce R.G.; Wright A.Remanent flux in current-transformer cores.Proceedings of the Institution ofElectrical Engineers; v113; n5; 1966; 915-920 ", short trouble in the electric power system or the exciting curent in the current transformer are crossed mostly can produce bigger remanent magnetism in current transformer.Bigger remanent magnetism is subjected to bigger harmful effect to the measurement of electric weight and the operate as normal of relay protection device.The physical property of ferromagnetic material has determined will produce remanent magnetism in the ferromagnetic material when exciting curent is decreased to zero.When other condition was constant, exciting curent was big more, and remanent magnetism is also big more.The electric current that the former limit of current transformer was passed through when electric power system normally moved is little, and exciting curent therefore unshakable in one's determination is also less.But when being short-circuited, primary current will increase sharply, and maximum can reach tens times of specified running current, and may have bigger DC component in the short circuit current.Exciting curent will increase this moment.The primary current zero passage stops during the excision short trouble.At this moment, will produce bigger remanent magnetism in the iron core.Because exciting curent is very little during the current transformer operate as normal, the remanent magnetism that produces during to the short circuit magnetic action of not dispelling substantially, thereby the life period of remanent magnetism can surpass some months.Operating characteristic when the existence of remanent magnetism will influence operation of current transformers will hinder accurately and measure.For suppressing remanent magnetism, there is a kind of method to be to use the little ferromagnetic material of coercive force, as permalloy or non-crystalline material, but the price of these materials is higher, will increase the manufacturing cost of instrument transformer exponentially.In addition, in document " Conner E.E.; Greb R.G.; Wentz E.C.Control ofresidual flux in current transformers.IEEE Transactions on Power Apparatus andSystems; vPAS-92; n4,1973,1226-1233 ", proposed to utilize the method that on iron core, increases by a small air gap to suppress remanent magnetism in the current transformer.The error when but this method will reduce the capacity of instrument transformer and increase operate as normal.But this method will increase leakage field and reduce accuracy of measurement, make also inconvenient.
Summary of the invention
The purpose of this invention is to provide a kind of amount meter type electromagnetic current transducer remanent magnetism inhibition method.It is characterized in that: this method is at the secondary of electromagnetic current transducer 1 and loads between 3 and connect remanent magnetism restraining device 2.Remanent magnetism restraining device 2 is actual to be a pressure limiting device, promptly work as short circuit current by current transformer 1 former limit, when current transformer 1 secondary output current surpasses the thresholding of setting, the electric current of current transformer 1 secondary flows through main branch road from remanent magnetism restraining device 2 places, the output voltage of current transformer 1 secondary is limited to preset level simultaneously, magnetic flux in the iron core will not be restricted and can significantly increase, remanent magnetism will be limited in electric current termination back core, can be not excessive, the error of current transformer 1 also can obviously not increase.
Voltage stabilizing that described remanent magnetism restraining device 2 is a differential concatenation or rectifier diode, transient voltage suppress diode or metal oxide varistor etc.
The invention has the beneficial effects as follows does not have complicated detection and control circuit in the remanent magnetism restraining device, effectively simple, the reliability height.Cheap, realize easily.Simultaneously to original structure of current transformer and not obviously influence of operate as normal.
Description of drawings
Fig. 1 is the current transformer schematic diagram that has the remanent magnetism restraining device.
Fig. 2 is several remanent magnetism restraining devices: (a) voltage stabilizing of differential concatenation or rectifier diode; (b) transient voltage suppresses diode; (c) metal oxide varistor.
Embodiment
The present invention is a kind of amount meter type electromagnetic current transducer remanent magnetism inhibition method.This method is at the secondary of electromagnetic current transducer 1 and loads between 3 and connect remanent magnetism restraining device 2 (as shown in Figure 1).Under normal running status, the electric current of current transformer 1 secondary is near rated value, at this moment, the remanent magnetism restraining device 2 of actual pressure limiting device is high-impedance state, obstructed overcurrent, electric current all through the 3 branch roads circulation of loading, therefore can not constitute influence to the measurement of electric current and the metering of electric energy.When short circuit current passes through the former limit of instrument transformer, when current transformer secondary output current surpasses the thresholding of setting, remanent magnetism restraining device 2 will become low resistive state by high-impedance state, the electric current of current transformer 1 secondary flows through main branch road by remanent magnetism restraining device 2 places, and the output voltage of current transformer secondary is limited to preset level simultaneously.According to the operation principle of current transformer as can be known: electromotive force and output voltage in the secondary coil are suitable, and the magnetic flux in electromotive force and the iron core is proportional.Therefore, after the output voltage of instrument transformer secondary is restricted, the magnetic flux in the iron core will not be restricted and can significantly increase.Therefore remanent magnetism will be limited under certain level in the electric current termination back core, can be not excessive, and the error of instrument transformer also can obviously not increase.The action adjustable threshold value of remanent magnetism restraining device is to adapt to the situation of different load and operating current.
Figure 2 shows that constituting of remanent magnetism restraining device 2: (a) voltage stabilizing of differential concatenation or rectifier diode; (b) transient voltage inhibition diode or (c) metal oxide varistor.
Claims (2)
1. amount meter type electromagnetic current transducer remanent magnetism inhibition method, it is characterized in that: this method is between the secondary of electromagnetic current transducer (1) and load (3) and connects remanent magnetism restraining device (2); Remanent magnetism restraining device (2) is actual to be a pressure limiting device, promptly work as short circuit current by the former limit of current transformer (1), when current transformer (1) secondary output current surpasses the thresholding of setting, the electric current general of current transformer (1) secondary is mainly flow through from the branch road at remanent magnetism restraining device (2) place, the output voltage of current transformer (1) secondary is limited to preset level simultaneously, magnetic flux in the iron core will not be restricted and can significantly increase, remanent magnetism will be limited in electric current termination back core, can be not excessive, the error of current transformer (1) also can obviously not increase.
2. according to the described amount meter of claim 1 type electromagnetic current transducer remanent magnetism inhibition method, it is characterized in that: described remanent magnetism restraining device (2) is the voltage stabilizing of differential concatenation or rectifier diode, transient voltage inhibition diode or metal oxide varistor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2004100427018A CN1305085C (en) | 2004-05-21 | 2004-05-21 | Metering type electromagnetic current mutual inductor redidual magnetism inhibiting method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2004100427018A CN1305085C (en) | 2004-05-21 | 2004-05-21 | Metering type electromagnetic current mutual inductor redidual magnetism inhibiting method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1581382A true CN1581382A (en) | 2005-02-16 |
| CN1305085C CN1305085C (en) | 2007-03-14 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2004100427018A Expired - Fee Related CN1305085C (en) | 2004-05-21 | 2004-05-21 | Metering type electromagnetic current mutual inductor redidual magnetism inhibiting method |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103969488A (en) * | 2013-01-31 | 2014-08-06 | 西门子公司 | Current transformer and current detection circuit thereof |
| CN112034231A (en) * | 2020-07-21 | 2020-12-04 | 华北电力大学 | High-frequency current sensor based on frequency-dependent integral resistor |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5923548A (en) * | 1997-03-28 | 1999-07-13 | Reltec Corporation | Active clamp used to maintain proper current transformer operation |
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2004
- 2004-05-21 CN CNB2004100427018A patent/CN1305085C/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103969488A (en) * | 2013-01-31 | 2014-08-06 | 西门子公司 | Current transformer and current detection circuit thereof |
| CN103969488B (en) * | 2013-01-31 | 2017-09-29 | 西门子公司 | Current transformer and its current detection circuit |
| CN112034231A (en) * | 2020-07-21 | 2020-12-04 | 华北电力大学 | High-frequency current sensor based on frequency-dependent integral resistor |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1305085C (en) | 2007-03-14 |
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Granted publication date: 20070314 Termination date: 20110521 |