CN102981035A - Current clamp and power quality monitoring device - Google Patents
Current clamp and power quality monitoring device Download PDFInfo
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- CN102981035A CN102981035A CN2012105235324A CN201210523532A CN102981035A CN 102981035 A CN102981035 A CN 102981035A CN 2012105235324 A CN2012105235324 A CN 2012105235324A CN 201210523532 A CN201210523532 A CN 201210523532A CN 102981035 A CN102981035 A CN 102981035A
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Abstract
The invention discloses a current clamp and a power quality monitoring device. The current clamp comprises a current induction device which comprises an iron core and a direct current component separating device, wherein the iron core is provided with a cavity matched with a measurement main body; when the measurement main body passes through the cavity, the electromagnetic induction is generated; the current induction device acquires grounding current signals in the measurement main body through the electromagnetic induction; and the direct current component separating device is connected with the current induction device to separate the alternating current from the direct current in the grounding current signals, so as to obtain and output the direct current component signal and the alternating current component signal. By virtue of the current clamp and the power quality monitoring device, the alternating current signal and the direct current signal of the grounding current at the transformer center point are synchronously measured, so that the research on the grounding direct current magnetic bias and the monitor of the power quality at the transformer center point can be performed according to the synchronously measured data of the alternating current and the direct current in the grounding current at the transformer center point.
Description
Technical field
The present invention relates to field of electrical equipment, in particular to a kind of current clamp and equipment for monitoring power quality.
Background technology
Can produce larger direct current in the Transformer Winding of on-line operation, we have the phenomenon of DC current to be referred to as the electric current bias phenomenon in alternating current with this, and producing DC magnetic bias phenomena in the Transformer Winding can be caused by following two reasons:
(1) earth magnetism " storm " of the dynamic change of sun plasma wind and terrestrial magnetic field interaction generation.The variation of terrestrial magnetic field will be brought out electric potential gradient at the earth's surface;on the face of the globe, its size depends on the order of severity of ground conductivity and earth magnetism storm, when this low frequency and electric field action with certain duration during in the power transformer of neutral ground, to in winding, bring out geomagnetic induction current, its frequency is between 0.01～1Hz, compare with the AC system of 50Hz, can be similar to and regard direct current as.This DC current values is larger, but the duration is short.
(2) there is the load of voltage-current relationship curve asymmetric in the parallel running of DC power transmission line and transmission line of alternation current or the AC network.DC transmission system usually adopts monopole operating mode, because can utilize this good conductor of the earth, saves a wire and saves cost.Because Underground Long-term has large DC current to flow through, thereby around its current conversion station, can produce the earth's surface electric current in the certain area, if not far apart from current conversion station with the transformer in the AC transmission system transformer station of its parallel running, will be interfered, the direct performance of this interference effect is exactly that grounded neutral by AC transformer produces DC component in the exciting current of AC transformer.This DC current values is less, but the duration is longer.
Produce DC magnetic bias phenomena in the transformer of on-line operation, direct current flux be so that transformer core more serious magnetic saturation will occur every half period, the exciting current high distortion, produce a large amount of harmonic waves, the transformer reactive loss increases, and core loss increases, and noise and vibration increase.Serious magnetic saturation meeting makes under normal circumstances magnetic flux closed in iron core partly leave iron core, be that leakage flux increases, thereby the stray loss in the transformer hardware is increased, may cause it overheated, destroy insulation, damage transformer or reduce its serviceable life.In addition, DC magnetic biasing also is the key factor that affects the quality of power supply of electric system.
In order to reduce DC magnetic biasing on the loss of transformer and on the impact of the quality of power supply, the alternating current and the DC current that need measuring transformer centre-point earth, carry out deep research with the DC magnetic bias phenomena to transformer, yet be directed to the medium of this special cross-section of high-power transformer centre-point earth steel plate in the prior art, flexible current pincers only can measuring transformer centre-point earth steel plate alternating current, the AC and DC current weight of measuring transformer centre-point earth steel plate simultaneously.
For the AC and DC component that can't measure simultaneously high-power transformer centre-point earth steel plate in the prior art, thereby can't carry out according to the AC and DC component of transformer central point ground connection the problem of the research of transformer DC magnetic bias, not yet propose at present effective solution.
Summary of the invention
For the AC and DC component that can't measure simultaneously high-power transformer centre-point earth steel plate in the correlation technique, thereby can't carry out according to the AC and DC component of transformer central point ground connection the problem of the research of transformer DC magnetic bias, effective solution is not yet proposed at present, for this reason, fundamental purpose of the present invention is to provide a kind of current clamp and equipment for monitoring power quality, to address the above problem.
To achieve these goals, according to an aspect of the present invention, a kind of current clamp is provided, this current clamp comprises: current sensing means, comprise iron core, iron core has the cavity that is complementary with the measurement body, produces electromagnetic induction when body passes cavity when measuring, and current sensing means obtains the ground current signal of measuring in the body by electromagnetic induction; The DC component tripping device is connected with current sensing means, is used for the ground current signal is carried out the AC and DC current separation, to obtain and output DC component signal and AC compounent signal.
Further, current sensing means comprises: be wrapped in the iron core winding on the iron core, wherein, iron core comprises the first sub-iron core and the second sub-iron core, wherein, one end of the first sub-iron core is blind end, the other end is openend, and the openend of the first sub-iron core is connected with the second sub-iron core, forms cavity with the inside at iron core, wherein, cavity is rectangular enclosure; The iron core winding is wrapped on the first sub-iron core.
Further, the DC component tripping device comprises: the DC component separation circuit, be connected with the first output terminal of iron core winding, and be used for the ground current signal that the first output terminal of iron core winding is exported is carried out current separation, to obtain the DC component signal; Dc output end is connected with the DC component separation circuit, is used for the output DC component signal; Ac output end is connected with the second output terminal of iron core winding, is used for output ground current signal.
Further, the DC component tripping device comprises: current suppling circuit, be connected with the DC component separation circuit, and be used to DC component segregant circuit that electric energy is provided.
Further, the openend of the first sub-iron core comprises the first sub-openend and the second sub-openend, wherein, the first sub-openend is connected by the first end of articulated elements with the second sub-iron core, under the state of the first sub-iron core and the second sub-iron core fastening, the second sub-openend is connected with the second end of the second sub-iron core, the first sub-iron core and the second sub-iron core formation iron core that is fastened and connected.
Further, articulated elements comprises elastic locking mechanism.
Further, in the outside of the blind end of the first sub-iron core handle is installed, the DC component tripping device is installed in the inside of handle.
Further, at the outer wrap insulating material of current sensing means.
To achieve these goals, according to a further aspect in the invention, provide a kind of equipment for monitoring power quality, this equipment for monitoring power quality comprises current clamp.
Further, equipment for monitoring power quality also comprises: the first harvester, be connected with the ac output end of current clamp, and be used for gathering ac current signal; The second harvester is connected with the dc output end of current clamp, is used for gathering dc current signal.
By the present invention, the iron core of the current sensing means of current clamp has the cavity that is complementary with the measurement body, so that when the measurement body passes the cavity of this iron core, produce electromagnetic induction, so that current sensing means obtains the ground current signal of measuring in the body by electromagnetic induction, then the DC component tripping device carries out separating of direct current and AC compounent with this ground current signal, obtain and output DC component signal and AC compounent signal, solved the AC and DC component that to measure simultaneously high-power transformer centre-point earth steel plate in the prior art, thereby can't carry out according to the AC and DC component of transformer central point ground connection the problem of the research of transformer DC magnetic bias, realized the ac current signal of transformer central point ground current and the synchro measure of dc current signal, thereby can carry out the research of transformer central point ground connection DC magnetic biasing and the monitoring of the quality of power supply according to the synchro measure data of alternating current-direct current in the transformer central point ground current.
Description of drawings
Accompanying drawing described herein is used to provide a further understanding of the present invention, consists of the application's a part, and illustrative examples of the present invention and explanation thereof are used for explaining the present invention, do not consist of improper restriction of the present invention.In the accompanying drawings:
Fig. 1 is the structural representation according to the current clamp of the embodiment of the invention;
Fig. 2 is the principle of work synoptic diagram according to the current clamp of the embodiment of the invention;
Fig. 3 is the detailed construction synoptic diagram according to the current clamp of the embodiment of the invention; And
Fig. 4 is the structural representation according to the equipment for monitoring power quality of the embodiment of the invention.
Embodiment
Need to prove that in the situation of not conflicting, embodiment and the feature among the embodiment among the application can make up mutually.Describe below with reference to the accompanying drawings and in conjunction with the embodiments the present invention in detail.
Fig. 1 is the structural representation according to the current clamp of the embodiment of the invention.Fig. 2 is the principle of work synoptic diagram according to the current clamp of the embodiment of the invention.Fig. 3 is the detailed construction synoptic diagram according to the current clamp of the embodiment of the invention.
As shown in Figure 1, current clamp provided by the invention comprises: current sensing means 10, comprise iron core 101, iron core 101 has the cavity that is complementary with the measurement body, produce electromagnetic induction when body passes cavity when measuring, current sensing means 10 obtains the ground current signal of measuring in the body by electromagnetic induction; DC component tripping device 30 is connected with current sensing means 10, is used for the ground current signal is carried out the AC and DC current separation, to obtain and output DC component signal and AC compounent signal.
Adopt current clamp of the present invention, produce electromagnetic induction by current sensing means and measurement body, to obtain the ground current signal of measuring in the body, the DC component tripping device is connected with current sensing means, the ground current signal that the DC component tripping device is obtained carries out the AC and DC current separation, to obtain and output DC component signal and AC compounent signal, wherein, current sensing means comprises iron core, iron core has the cavity that is complementary with the measurement body, produce electromagnetic induction when body passes cavity when measuring, current sensing means obtains the ground current signal of measuring in the body by electromagnetic induction.Pass through the application, the iron core of the current sensing means of current clamp has the cavity that is complementary with the measurement body, when can passing the cavity of iron core, body produces electromagnetic induction so that measure, so that current sensing means obtains the ground current signal of measuring in the body by electromagnetic induction, then the DC component tripping device carries out separating of direct current and AC compounent with this ground current signal, obtain and output DC component signal and AC compounent signal, solved the AC and DC component that to measure simultaneously high-power transformer centre-point earth steel plate in the prior art, thereby can't carry out according to the AC and DC component of transformer central point ground connection the problem of the research of transformer DC magnetic bias, realized the ac current signal of transformer central point ground current and the synchro measure of dc current signal, thereby can carry out the research of transformer DC magnetic bias according to the synchro measure data of alternating current-direct current in the transformer central point ground current.
Wherein, measuring body can be the transformer central point earthing device, and particularly, the transformer central point earthing device can be transformer central point ground connection steel plate.
In above-described embodiment of the application, as shown in Figure 2, current sensing means 10 comprises: be wrapped in the iron core winding on the iron core 101, wherein, iron core 101 comprises the first sub-iron core and the second sub-iron core, particularly, as shown in Figure 3, an end of the first sub-iron core is blind end, the other end is openend, the openend of the first sub-iron core is connected with the second sub-iron core, forms cavity with the inside at iron core 101, wherein, cavity is rectangular enclosure, measure body and pass rectangular enclosure, so that iron core 101 produces electromagnetic induction with measuring body, and in iron core 101, generate an electromagnetic field; The iron core winding is wrapped on the first sub-iron core, is used for obtaining the ground current signal by the electromagnetic induction with electromagnetic field.
Particularly, current clamp shown in Figure 3, the openend of the first sub-iron core comprises the first sub-openend and the second sub-openend, wherein, the first sub-openend is connected by the first end of articulated elements with the second sub-iron core, under the state of the first sub-iron core and the second sub-iron core fastening, the second sub-openend is connected with the second end of the second sub-iron core, and the first sub-iron core and the second sub-iron core are fastened and connected and form iron core 101.
Wherein, the articulated elements in above-described embodiment can comprise elastic locking mechanism.Particularly, elastic locking mechanism uses spring to realize elastic locking.
Particularly, as shown in Figures 2 and 3, the the second sub-iron core that is connected with the openend of the first sub-iron core of current clamp in above-described embodiment is opened, to open the rectangular enclosure of iron core 101, pass rectangular enclosure so that measure body, then the first sub-iron core and the second sub-iron core are fastened, so that the inside of iron core 101 forms above-mentioned rectangular enclosure, then just can measure the ground current signal of measuring body by current clamp, in measuring process, measure body as a winding, because measuring in the body has alternating current to flow through, iron core 101 can be responded to this alternating current and produce electromagnetism, and the iron core winding (this iron core winding is as Secondary Winding in measuring process) that then is wrapped on the iron core 101 obtains the ground current signal by electromagnetic induction, and exports this ground current signal to DC component tripping device 30.
Wherein, the length of rectangular enclosure can be 50cm, and the width of rectangular enclosure can be 10cm, and wherein, as shown in Figure 3, the width of rectangular enclosure also is the A/F of the openend of the first sub-iron core.
Particularly, this current clamp is applied in the measurement of transformer central point ground current signal, as shown in Figures 2 and 3, the first sub-iron core of this current clamp has openend, and the sizes at iron core 101 inner formation cavitys are complementary with the measurement bodies, thereby can realize the measurement to the ground current signal of the wide cross section of transformer central point ground connection wire.
In the above embodiment of the present invention, DC component tripping device 30 can comprise: the DC component separation circuit, be connected with the first output terminal of iron core winding, be used for the ground current signal that the first output terminal of iron core winding is exported is carried out current separation, to obtain the DC component signal; Dc output end is connected with the DC component separation circuit, is used for the output DC component signal; Ac output end is connected with the second output terminal of iron core winding, is used for output ground current signal.Wherein, the ground current signal of ac output end output is as the ground current signal, also comprised the DC component signal although both comprised the AC compounent signal in this ground current signal, but in the follow-up process that ac current signal is processed, DC component wherein can't be influential to follow-up processing.
Wherein, DC component tripping device 30 can also comprise: current suppling circuit, be connected with the DC component separation circuit, and be used to DC component segregant circuit that electric energy is provided.
Above-described embodiment by the application, but current clamp comprise opening iron core 101, be wrapped in iron core winding, DC component separation circuit and double output ends on the iron core 101, iron core 101 and iron core winding can cooperate the ground current signal that obtains the measurement body by electromagnetic induction, then the DC component separation circuit is separated the DC component in the ground current signal, and by double output ends direct current and AC compounent signal are exported respectively, thereby can measure simultaneously alternating current and DC component in the body.
In the above embodiment of the present invention, can handle be installed in the outside of the blind end of the first sub-iron core, DC component tripping device 30 can be installed in the inside of handle.DC component tripping device 30 can be installed in the inside of handle, can reduce the volume of current clamp, thereby so that carrying of current clamp is more convenient.
In addition, can the wrap insulate material in the outside of current sensing means 10, can realize security measurement, protection person's safety well, decrease safent accident.
Fig. 4 is the structural representation according to the equipment for monitoring power quality of the embodiment of the invention, and equipment for monitoring power quality as shown in Figure 4 comprises current clamp 1.
Pass through the application, the iron core of the current sensing means of current clamp has the cavity that is complementary with the measurement body, so that when the measurement body passes the cavity of this iron core, produce electromagnetic induction, so that current sensing means obtains the ground current signal of measuring in the body by electromagnetic induction, then the DC component tripping device carries out separating of direct current and AC compounent with this ground current signal, obtain and output DC component signal and AC compounent signal, solved the AC and DC component that to measure simultaneously high-power transformer centre-point earth steel plate in the prior art, thereby can't carry out according to the AC and DC component of transformer central point ground connection the problem of the research of transformer DC magnetic bias, realized the ac current signal of transformer central point ground current and the synchro measure of dc current signal, thereby can carry out electric energy quality monitoring according to the synchro measure data of alternating current-direct current in the transformer central point ground current.
In the above embodiment of the present invention, equipment for monitoring power quality can also comprise: the first harvester 3, be connected with the ac output end of current clamp, and be used for gathering ac current signal; The second harvester 5 is connected with the dc output end of current clamp, is used for gathering dc current signal.Wherein, the ac current signal of ac output end output is above-mentioned ground current signal, also comprised the DC component signal although both comprised the AC compounent signal in this ground current signal, but in the follow-up process that ac current signal is processed, DC component wherein can't be influential to follow-up processing.
Equipment for monitoring power quality in above-described embodiment can be measured DC component.Wherein, treating apparatus in the equipment for monitoring power quality can carry out amperometry with the current signal that collects with the first harvester and the second harvester, particularly, amperometry comprises: analyze the regularity of distribution of dc current signal on time shaft, the waveform of comparative analysis dc current signal and the waveform of ac current signal, comparative analysis is with respect to the waveform of the ac current signal of these monitoring point electric energy quality monitoring data and the waveform of dc current signal, and obtain direct-current component in the pests occurrence rule of this electrical network node by the comparative analysis result to the above-mentioned regularity of distribution and waveform, correlativity according to this pests occurrence rule researching DC bias phenomenon and quality of power supply event, and can be when obtaining the electric energy quality monitoring data, the generation of prediction direct-current component (DC magnetic biasing).
Particularly, as shown in Figure 4, ac output end at current clamp connects the first harvester 3, and connect the second harvester 5 at dc output end, the first harvester 3 and the second harvester 5 gather respectively ac current signal and the dc current signal of current clamp output, and this ac current signal and dc current signal are applied in the follow-up electric energy quality monitoring.
From above description, can find out, the present invention has realized following technique effect: pass through the application, the iron core of the current sensing means of current clamp has the cavity that is complementary with the measurement body, so that when the measurement body passes the cavity of this iron core, produce electromagnetic induction, so that current sensing means obtains the ground current signal of measuring in the body by electromagnetic induction, then the DC component tripping device carries out separating of direct current and AC compounent with this ground current signal, obtain and output DC component signal and AC compounent signal, solved the AC and DC component that to measure simultaneously high-power transformer centre-point earth steel plate in the prior art, thereby can't carry out according to the AC and DC component of transformer central point ground connection the problem of the research of transformer DC magnetic bias, realized the ac current signal of transformer central point ground current and the synchro measure of dc current signal, thereby can carry out the research of transformer central point ground connection DC magnetic biasing and the monitoring of the quality of power supply according to the synchro measure data of alternating current-direct current in the transformer central point ground current.
The above is the preferred embodiments of the present invention only, is not limited to the present invention, and for a person skilled in the art, the present invention can have various modifications and variations.Within the spirit and principles in the present invention all, any modification of doing, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.
Claims (10)
1. a current clamp is characterized in that, comprising:
Current sensing means, comprise iron core, described iron core has and the cavity of measuring body and being complementary, and produces electromagnetic induction when described measurement body passes described cavity, and described current sensing means obtains ground current signal in the described measurement body by described electromagnetic induction;
The DC component tripping device is connected with described current sensing means, is used for described ground current signal is carried out the AC and DC current separation, to obtain and output DC component signal and AC compounent signal.
2. current clamp according to claim 1 is characterized in that, described current sensing means comprises: be wrapped in the iron core winding on the described iron core, wherein,
Described iron core comprises the first sub-iron core and the second sub-iron core, wherein,
One end of described the first sub-iron core is blind end, and the other end is openend, and the openend of described the first sub-iron core is connected with the second sub-iron core, forms described cavity with the inside at described iron core, and wherein, described cavity is rectangular enclosure;
Described iron core winding is wrapped on the described first sub-iron core.
3. current clamp according to claim 2 is characterized in that, described DC component tripping device comprises:
The DC component separation circuit is connected with the first output terminal of described iron core winding, is used for the ground current signal that the first output terminal of described iron core winding is exported is carried out current separation, to obtain the DC component signal;
Dc output end is connected with described DC component separation circuit, is used for exporting described DC component signal;
Ac output end is connected with the second output terminal of described iron core winding, is used for exporting described ground current signal.
4. current clamp according to claim 3 is characterized in that, described DC component tripping device comprises:
Current suppling circuit is connected with described DC component separation circuit, is used to described DC component segregant circuit that electric energy is provided.
5. current clamp according to claim 2, it is characterized in that, the openend of described the first sub-iron core comprises the first sub-openend and the second sub-openend, wherein, the described first sub-openend is connected by the first end of articulated elements with described the second sub-iron core, under the state of the described first sub-iron core and the described second sub-iron core fastening, the described second sub-openend is connected with the second end of described the second sub-iron core, and the described first sub-iron core and the described second sub-iron core are fastened and connected and form described iron core.
6. current clamp according to claim 5 is characterized in that, described articulated elements comprises elastic locking mechanism.
7. current clamp according to claim 2 is characterized in that, in the outside of the blind end of described the first sub-iron core handle is installed, and described DC component tripping device is installed in the inside of described handle.
8. current clamp according to claim 1 is characterized in that, at the outer wrap insulating material of described current sensing means.
9. an equipment for monitoring power quality is characterized in that, comprises the described current clamp of any one in the claim 1 to 8.
10. device according to claim 9 is characterized in that, described equipment for monitoring power quality also comprises:
The first harvester is connected with the ac output end of described current clamp, is used for gathering ac current signal;
The second harvester is connected with the dc output end of described current clamp, is used for gathering dc current signal.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201210523532.4A CN102981035B (en) | 2012-12-07 | 2012-12-07 | Current clamp and power quality monitoring device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210523532.4A CN102981035B (en) | 2012-12-07 | 2012-12-07 | Current clamp and power quality monitoring device |
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| Publication Number | Publication Date |
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| CN102981035A true CN102981035A (en) | 2013-03-20 |
| CN102981035B CN102981035B (en) | 2015-04-22 |
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| CN201210523532.4A Expired - Fee Related CN102981035B (en) | 2012-12-07 | 2012-12-07 | Current clamp and power quality monitoring device |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN105425003A (en) * | 2015-11-16 | 2016-03-23 | 国网河南省电力公司平顶山供电公司 | Two-way information interaction method and two-way information interaction device for watt-hour meter boxes of residents |
| CN112362953A (en) * | 2020-09-16 | 2021-02-12 | 昆明理工大学 | Direct current bias current detection device |
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| CN102981035B (en) | 2015-04-22 |
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Granted publication date: 20150422 Termination date: 20181207 |