CN101498745A - Current detecting device and method - Google Patents
Current detecting device and method Download PDFInfo
- Publication number
- CN101498745A CN101498745A CNA2008100032204A CN200810003220A CN101498745A CN 101498745 A CN101498745 A CN 101498745A CN A2008100032204 A CNA2008100032204 A CN A2008100032204A CN 200810003220 A CN200810003220 A CN 200810003220A CN 101498745 A CN101498745 A CN 101498745A
- Authority
- CN
- China
- Prior art keywords
- current
- electric current
- detected
- testing result
- sense channel
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Abstract
The invention discloses a current detecting device which comprises a current sensor. The current sensor comprises two detecting channels and a detecting processor, wherein one detecting channel is suitable for detecting high current, the other detecting channel is suitable for detecting low current, and the two detecting channels are respectively used for detecting the same current to obtain detecting results; and the detecting processor is used for choosing a detecting result with higher precision from the detecting results of the two detecting channels of the current sensor as a final detecting result to be output. The invention simultaneously discloses a current detecting method. Through the application of the current detecting device and the current detecting method, high-precision detection can be conveniently realized in a wider detecting range.
Description
Technical field
The present invention relates to current detection technology, particularly relate to a kind of current sensing means and a kind of electric current detecting method.
Background technology
Current, the breaker of plastic casing of charged sub-electrical apparatus release (ETU, Electronic Trip Unit) (MCCB, Moulded Case Circuit Breaker) has been widely used in various route protections and the electric motor protecting.MCCB ETU mainly is made up of three parts, that is: the moving accumulation of energy transducer of current sensor, electronic circuit control module and magnetic.Wherein, current sensor is used to detect the size of current on the protection circuit, and sends testing result to the electronic circuit control module; The electronic circuit control module judges according to the testing result that receives whether circuit breaks down, if break down, then sends trip signal to the moving accumulation of energy transducer of magnetic, is triggered the trip gear of breaker of plastic casing by the moving accumulation of energy transducer of magnetic and threads off.
Based on above-mentioned introduction as can be known, current sensor is an important component part among the MCCB ETU, and its performance will have influence on the protective value of whole M CCB ETU greatly.So, in actual applications, as the current sensor that is applied among the MCCB ETU, below the performance need of three aspects cause concern:
(1) current detection accuracy and the range of linearity
MCCB ETU possesses three-stage protection function usually, that is: overload long delay protection, the protection of short circuit short time delay and the moving protection of short circuit wink.For realizing this three-stage protection function; require current sensor need possess the current detecting performance of degree of precision and the linearity of relative broad range; the current detecting scope that promptly possesses broad, such as, in the scope of current value from 0.2In to 10In, all should possess higher current detection accuracy.Wherein, In is the rated primary current of MCCB ETU.
(2) output power signal and power supply capacity
MCCB ETU must not allow any additional external power supply that MCCB ETU is powered from directly power supply on the main protection circuit.Generally, the output signal that is applied to the current sensor among the MCCB ETU need have certain power, on the one hand as signal source, on the other hand as the power supply to the electronic circuit control module for power supply.According to general requirement, the output signal of current sensor is as power source, needs to make MCCB ETU to start working under the situation of 0.2In.
(3) isolation and antijamming capability
For guaranteeing the safe in utilization of MCCB ETU, the current sensor that is applied among the MCCB ETU must effectively be isolated main protection circuit and electronic circuit control module.In addition, because generally, need in three phase lines and a center line, a current sensor be installed respectively, to detect the size of current on every route road, so current sensor need be able to be avoided the electromagnetic interference (EMI) between each phase line.
In the prior art, can adopt multiple sensing technology to detect size of current, as, Hall chip (HallChip), giant magnetoresistance (GMR, Giant Magneto Resistor), giant magnetic impedance (GMI, Giant MagnetoImpedance), photoelectric sensor (OTC, Optical Current Transformer), Luo-coil (Rogowski Coil) and current diverter (Current Shunt) etc.But, consider the factors such as requirement restriction of cost, volume, output power signal, so far, the current transformer (CT, Current Transformer) that among the MCCB ETU will be iron core with silicon steel is as its current sensor.
Fig. 1 is the equivalent-simplification circuit diagram of the CT of iron core for having now with silicon steel.As shown in Figure 1, the primary winding of CT and the no-load voltage ratio n between the secondary coil are:
Wherein, N
PBe the primary winding number of turn,, have only punching one circle usually for MCCB ETU; N
SBe the secondary coil number of turn.
As shown in Figure 1, I
mBe total current, I
pFor can detected primary current, and exciting current I
mFor expend the electric current that falls owing to reasons such as iron loss, be detect less than, so the detection error of CT is mainly by I
mInstitute causes that therefore, the current detection accuracy of CT can be expressed as:
From formula (2) as can be seen, exciting current I
mSize directly determined the current detection accuracy of CT, and exciting current I
mSize then depend on the B-H magnetic hysteresis loop characteristic and the eddy current loss of silicon steel core.
Fig. 2 is the BH curve schematic diagram of existing silicon steel core.As shown in Figure 2, magnetic induction density B is the function that changes with magnetic field intensity H.At the BH curve section start, magnetic induction density B slowly rises to the A point with the increase of magnetic field intensity H, and the magnetic permeability that A is ordered is defined as initial permeability μ
iSubsequently, magnetic induction density B is climbed to the B point with magnetic field intensity H, and this point is called the flex point of BH curve, and the magnetic permeability that B is ordered is defined as maximum permeability μ
MaxAfter this, magnetic induction density B increases with the increase of magnetic field intensity H hardly, and silicon steel core is in state of saturation.
If the working point of the silicon steel core of CT is positioned at below the A point or more than the B point, promptly the working point is positioned at the inelastic region of BH curve, so, the current detection accuracy of CT will seriously reduce.So, when design CT silicon steel core,, can design the volume of the silicon steel core of CT bigger usually, so that the linear zone of its working point between A and B for guaranteeing in the scope of 0.2In～10In, all to have higher current detection accuracy.
Based on above analysis as can be known, in the prior art, be that the CT of iron core mainly has following shortcoming with silicon steel:
(1) owing to can only the electric current in from 0.2In to the 10In scope be detected usually, so, for each MCCB ETU, all need to have the CT corresponding with it with certain rated primary current;
(2) silicon steel core among the CT need have bigger size, in the linear zone that is operated in BH curve.
As seen, when adopting existing silicon steel core CT to carry out current detecting, each MCCB ETU will have and the corresponding CT of its rated primary current, sensing range is less, has only 0.2In usually to 10In, and, if guarantee current detection accuracy in this scope, also need to increase the size of silicon steel core among the CT, very inconvenient, and increased cost.
Summary of the invention
Another purpose of the present invention is to provide a kind of current sensing means, can realize that easily current with high accuracy detects in the broad sensing range.
A further object of the present invention is to provide a kind of electric current detecting method, can realize that easily current with high accuracy detects in the broad sensing range.
For achieving the above object, technical scheme of the present invention is achieved in that
A kind of current sensing means, comprise: a current sensor, described current sensor comprises two sense channels, one of them sense channel is applicable to big electric current is detected, another sense channel is applicable to little electric current is detected that described two sense channels are used for respectively same electric current being detected and obtain testing result; A measurement processor is used for selecting higher one of accuracy of detection to export as final detection result from the testing result of two sense channels of described current sensor.
The described sense channel that little electric current is detected that is applicable to adopts the nano microcrystalline current transformer.
The described sense channel that big electric current is detected that is applicable to adopts Luo-coil.
Described measurement processor comprises: a judging unit is used for the testing result and the predefined current value of one of them described sense channel are compared judgement; A selected cell, be used in the testing result of this sense channel of judgment unit judges during greater than described predefined current value, select the described testing result of the sense channel that big electric current is detected that is applicable to export as final detection result, during less than described predefined current value, select the described testing result of the sense channel that little electric current is detected that is applicable to export in the testing result of this sense channel of judgment unit judges as final detection result.
A kind of electric current detecting method, comprise: two sense channels are set respectively same electric current are detected and obtain testing result, wherein, a described sense channel is applicable to big electric current is detected that another described sense channel is applicable to little electric current is detected; From the testing result of described two sense channels, select higher one of accuracy of detection to export as final detection result.
The described sense channel that little electric current is detected that is applicable to adopts the nano microcrystalline current transformer.
The described sense channel that big electric current is detected that is applicable to adopts Luo-coil.
From the testing result of described two sense channels, select a higher step of exporting as final detection result of accuracy of detection to comprise: the testing result of one of them sense channel is compared with predefined current value; If the testing result of judging this sense channel greater than described predefined current value, is then exported the described testing result of the sense channel that big electric current is detected that is applicable to as final detection result; Otherwise, the described testing result of the sense channel that little electric current is detected that is applicable to is exported as final detection result.
The described sense channel that its testing result and predefined current value are compared is preferably the sense channel that adopts the nano microcrystalline current transformer.
As seen, in the technical scheme of the present invention, adopt two passages in the binary channels current sensor, promptly nano microcrystalline current transformer and Luo-coil detect same electric current respectively simultaneously, obtain two kinds of testing results and handle after obtain final detection result.Above-mentioned current sensor of the present invention and measurement processor cooperating can be realized above-mentioned electric current detecting method of the present invention.Binary channels current sensor in the embodiment of the invention has made full use of that the nano microcrystalline current transformer be fit to detect little electric current and Luo-coil is fit to detect big characteristics of current, has enlarged the scope of current detecting and has improved the precision of current detecting.
Description of drawings
To make clearer above-mentioned and other feature and advantage of the present invention of those of ordinary skill in the art by describing the preferred embodiments of the present invention in detail below with reference to accompanying drawing, in the accompanying drawing:
Fig. 1 is the equivalent-simplification circuit diagram of the CT of iron core for having now with silicon steel;
Fig. 2 is the BH curve schematic diagram of existing silicon steel core;
Fig. 3 is the composition structural representation of the current sensing means in the embodiment of the invention;
Fig. 4 is the Luo-coil basic principle schematic in the embodiment of the invention;
Test findings when Fig. 5 carries out the current detection accuracy test for adopting the binary channels current sensor that has now in the silicon steel core CT and the embodiment of the invention in the embodiment of the invention is synoptic diagram relatively;
Fig. 6 is the electric current detecting method process flow diagram in the embodiment of the invention.
Embodiment
In order to make purpose of the present invention, technical scheme and advantage clearer,, the present invention is further elaborated below in conjunction with drawings and Examples.Should be appreciated that specific embodiment described herein only in order to explanation the present invention, and be not used in qualification the present invention.
For solving problems of the prior art, a kind of current sensing means is proposed in the embodiment of the invention, as shown in Figure 3, Fig. 3 is the composition structural representation of the current sensing means in the embodiment of the invention, comprising: a current sensor 31 and a measurement processor 32.Current sensor 31 comprises two sense channels, and one of them sense channel is applicable to big electric current is detected that another sense channel is applicable to little electric current is detected that two sense channels detect and obtain testing result to same electric current respectively; Measurement processor 32 is used for selecting higher one of accuracy of detection to export as final detection result from the testing result of two sense channels of current sensor 31.
Wherein, current sensor 31 is the binary channels current sensor, and as shown in Figure 3, this binary channels current sensor mainly is made up of nano microcrystalline CT 311 and Luo-coil 312 two parts.Wherein: nano microcrystalline CT 311 and Luo-coil 312, be respectively applied for same circuit to be detected is carried out current detecting, and the output testing result.Owing to different detection modes is arranged respectively for big or small electric current, do not need for making iron core is operated in additionally increases iron core in the linear zone of BH curve size, so the size of this binary channels current sensor is approaching with the existing silicon steel core CT that is applied among the MCCB ETU, can satisfy the requirement of MCCB ETU to aspects such as the physical dimension of current sensor and cost control, and, can arrive in the broad sensing range of several kiloamperes at several amperes, detect electric current accurately.
As shown in Figure 3, further comprise in the measurement processor 32: judging unit 321 and selected cell 322: judging unit 321 is used for the testing result and the predefined current value of a sense channel of current sensor 31 are compared judgement; Selected cell 322, the testing result that is used for judging these sense channels at judging unit 321 is during greater than described predefined current value, select the described testing result of the sense channel that big electric current is detected that is applicable to export as final detection result, the testing result of judging these sense channels at judging unit 321 selects the described testing result of the sense channel that little electric current is detected that is applicable to export as final detection result during less than described predefined current value.
In actual applications, measurement processor 32 can be arranged in current sensor 31 or electronic circuit control module.When being arranged in current sensor 31, its specific implementation comprises: whether the testing result of judging nano microcrystalline CT311 output is greater than predefined current value, the big I of this predefined current value is provided with according to actual needs, if determine that then the electric current in the circuit to be detected is big electric current; Otherwise, determine that the electric current in the circuit to be detected is little electric current; If determine that the electric current in the circuit to be detected is big electric current, then the testing result of Luo-coil 312 exported to the electronic circuit control module; If determine that the electric current in the circuit to be detected is little electric current, then the testing result of nano microcrystalline CT311 exported to the electronic circuit control module.
Need to prove that in actual applications, the electric current that measurement processor 32 also can be carried out in the circuit to be detected according to the testing result of Luo-coil 312 outputs is that big electric current still is the judgement of little electric current, just degree of accuracy is relatively poor relatively.
When measurement processor 32 is arranged in the electronic circuit control module, its specific implementation comprises: the measurement processor that is arranged in the electronic circuit control module judges that whether the testing result of nano microcrystalline CT311 output is greater than predefined current value, the big I of this current value is provided with according to actual needs, if determine that then the electric current in the circuit to be detected is big electric current; Otherwise, determine that the electric current in the circuit to be detected is little electric current; And when the electric current in determining circuit to be detected is big electric current, adopt the testing result power supply electronic circuit control module of Luo-coil 312 outputs to carry out the judgement whether circuit to be detected breaks down; When the electric current in determining circuit to be detected is little electric current, adopt the testing result power supply electronic circuit control module of nano microcrystalline CT311 output to carry out the judgement whether circuit to be detected breaks down, concrete fault judgment method is a prior art, repeats no more.
Can detect little electric current accurately and detect big characteristics of current accurately because nano microcrystalline CT and Luo-coil have respectively, so, utilize both characteristics in the embodiment of the invention respectively, if the electric current in the current circuit to be detected is little electric current, so, according to the characteristics of above-mentioned nano microcrystalline CT as can be known, the precision of its testing result is better than Luo-coil, so, the electronic circuit control module is carried out subsequent calculations and judgement according to the testing result of nano microcrystalline CT, promptly carries out the judgement whether circuit to be detected breaks down; Otherwise, if the electric current in the current circuit to be detected is big electric current, so, according to the characteristics of above-mentioned Luo-coil as can be known, the precision of its testing result is better than nano microcrystalline CT, so the electronic circuit control module is carried out subsequent calculations and judgement according to the testing result of Luo-coil.Like this, utilize the binary channels current sensor, can detect little electric current and big electric current simultaneously accurately.
Performance to nano microcrystalline CT and Luo-coil describes in detail respectively below:
(1) nano microcrystalline CT
Nano microcrystalline CT with nano microcrystalline as iron core.Nano microcrystalline is a kind of amorphous band, and principal ingredient is iron (Fe), silicon (Si), boron (B) and a spot of copper (Cu) and niobium (Nb), and its liquid alloy metal is through making steel band up to the quenching of up to a million degrees centigrade of cooling velocities of per second.The performance that table one is depicted as silicon steel and nano microcrystalline compares.
The performance of table one silicon steel and nano microcrystalline relatively
| Material | Initial permeability μ i | Iron loss P (W/Kg, P1.0/1K) | Saturation induction density Bs/T |
| Silicon steel | 10000～16000 | 20 | 1.6～2.0 |
| Nano microcrystalline | 30000～80000 | 4 | 1.0～1.2 |
As shown in Table 1, the initial permeability of nano microcrystalline is three times of silicon steel, like this, for the iron core of same size, when detecting little electric current, because initial permeability is big more, magnetic induction density B is big more, magnetic induction density B is big more, and also to be arranged in the possibility of linear zone of BH curve shown in Figure 2 with regard to the working point of representing nano microcrystalline CT big more, so nano microcrystalline CT will obtain the current detection accuracy higher than silicon steel core CT.
In addition, as well known to those skilled in the art, iron loss also is a principal element that influences current detection accuracy.Iron loss is big more, exciting current I shown in Figure 1
mJust big more, and then cause current detection accuracy low more.And iron loss also can influence another performance index of CT, i.e. temperature rise.Core loss value is more little, and temperature rise is low more; And temperature rise is low more, and current detection accuracy is high more.According to the record in the table one as can be known, the iron loss of nano microcrystalline only is 1/5th of a silicon steel.So than silicon steel core CT, nano microcrystalline CT will have lower temperature rise and the current detection accuracy of Geng Gao.
Have, in the prior art, saturation induction density Bs has determined the precision of CT when big current detecting again.Saturation induction density Bs is big more, and current detection accuracy is high more.And according to the record in the table one as can be known, the saturation induction density Bs of nano microcrystalline is slightly less than silicon steel, like this, when carrying out big electric current, during as the current detecting of 8In～10In, under same core dimensions situation, than existing silicon steel core CT, the current detection accuracy of nano microcrystalline CT will be lower.
Based on top analysis as can be known, when detecting little electric current, nano microcrystalline CT will obtain the higher current detection accuracy than existing silicon steel core CT; But when detecting big electric current, the current detection accuracy of nano microcrystalline CT then will be lower than existing silicon steel core CT.
(2) Luo-coil
Detect electric current with Luo-coil and have following advantage:
At first, when detecting big electric current, the Luo-coil of same size can detect up to the electric current more than the 100KA, if but adopt silicon steel core CT, then need to increase core dimensions to detect big electric current.
Secondly and since in the Luo-coil not with ferromagnetic materials such as silicon steel as iron core, so saturated phenomenon can not occur, when detecting big electric current, current detection accuracy can not reduce because of core sataration like this.
But, when adopting Luo-coil to detect little electric current, but there is the not high problem of accuracy of detection, because: Fig. 4 is the basic principle schematic of the Luo-coil in the embodiment of the invention.Shown in Fig. 4 (a), when current lead passed Luo-coil, the secondary coil in the Luo-coil can produce a voltage signal e
0, this voltage signal e
0Be proportional to the coefficient of mutual inductance M and the primary current rate of change of coil
As shown in Equation (3):
Wherein, i (t) is a primary current, can be expressed as:
From formula (4) as can be seen, be to detect primary current, need carry out integration the output voltage signal of the secondary coil of Luo-coil, and with the value behind the integration divided by coefficient of mutual inductance M.
For the annular Luo-coil with square-section shown in Fig. 4 (b), its coefficient of mutual inductance M can be calculated as follows (being unit with MKS):
Wherein:
M is the coefficient of mutual inductance of Luo-coil, and unit is prosperous (H);
N is the secondary coil coiling density of Luo-coil, the coil turn in the representation unit length, and unit is circle/rice;
H is a coil height, and unit is a rice;
R
0Be coil outer diameter, unit is a rice;
R
iBe internal coil diameter, unit is a rice.
Because in the prior art, the concrete value of above-mentioned each parameter all is known, promptly and the existing silicon steel core CT that is used for MCCB ETU similar, so, can calculate coefficient of mutual inductance M according to formula (5), be about 0.1～1 μ H.Like this, when primary current only is tens amperes even when lower, it exports e
oJust have only several millivolt, such small-signal can very easily be interfered in actual applications, so, usually Luo-coil is applied to more than the hundreds of ampere in the big current detecting.
Need to prove that formula (5) is only applicable to have the annular Luo-coil of square-section, and the Luo-coil of being mentioned in the present embodiment all can think to have the annular Luo-coil of square-section.
Has These characteristics respectively just because of nano microcrystalline CT and Luo-coil, so, in the embodiment of the invention both are combined, form the binary channels current sensor, that is, combine the advantage of nano microcrystalline CT and Luo-coil, when carrying out actual current detecting, utilize nano microcrystalline CT to remove to detect little electric current, utilize Luo-coil to remove to detect big electric current.
Further specify the technique effect of the embodiment of the invention below by concrete test findings:
(1) current detection accuracy test
Technical indicator when table two is depicted as existing silicon steel core CT and the described binary channels current sensor of the embodiment of the invention carried out the current detection accuracy test, as shown in Table 2, wherein the rated primary current of silicon steel core CT is 160A, and specified secondary is output as 250mA; In the binary channels current sensor, the rated primary current of nano microcrystalline CT is 160A, and specified secondary is output as 100mA, and the rated primary current of Luo-coil is 300A, and specified secondary is output as 136mV.The test findings of table three for obtaining when under technical indicator shown in the table two, testing.For more clearly two kinds of schemes being compared, test findings shown in the table three can be represented with form shown in Figure 5.
Table two technical indicator
Table three test findings
As table three and shown in Figure 5, silicon steel core CT promptly has higher current detection accuracy in the scope of 0.4In～8In at 64A～1280A, but when electric current during less than 0.4In or greater than 8In, its current detection accuracy will obviously descend.And the binary channels current sensor that is provided in the embodiment of the invention all has higher current detection accuracy in the scope of 10A～3000A.
(2) output power signal and power supply capacity test
Be that current circuit control module among the MCCB ETU of 160A is connected with binary channels current sensor and rated primary current, slowly increase the size of primary current, measure the magnitude of voltage of the power module output in the electronic circuit control module simultaneously, and judge whether the electronic control unit (MCU, Microprocessor Control Unit) among the MCCB ETU starts working.Generally, have a pilot lamp on the MCU, when MCU started working, this pilot lamp can be made corresponding indication.By the way, the minimum that can test out MCCB ETU when utilizing the binary channels current sensor to power starts the working current size, and test findings as shown in Table 4.As can be seen from Table IV, when adopting the binary channels current sensor to power, when primary current reached 25A, rated primary current was that the MCCB ETU of 160A starts working.
Table four power supply test findings
| Primary current | 20A | 25A | 40A | 50A |
| The power module output voltage | 4V | 5V | 5V | 5V |
| Whether MCU works | Not | Be | Be | Be |
Based on above-mentioned introduction, a kind of electric current detecting method is proposed in the embodiment of the invention simultaneously, as shown in Figure 6, Fig. 6 is the electric current detecting method process flow diagram in the embodiment of the invention, specifically comprises the steps:
Step 61: two sense channels are set respectively same electric current are detected and obtain testing result.
Wherein, a sense channel is applicable to big electric current is detected that another sense channel is applicable to little electric current is detected.In present embodiment, promptly adopt Luo-coil and nano microcrystalline CT that same electric current is detected respectively.
Step 62: from the testing result of two sense channels, select higher one of accuracy of detection to export as final detection result.
The specific implementation of this step can comprise: the testing result of one of them sense channel is compared with predefined current value; If the testing result of judging this sense channel, will be applicable to then that the testing result of the sense channel that big electric current is detected is as final detection result greater than predefined current value; Otherwise, will be applicable to that the testing result of the sense channel that little electric current is detected is as final detection result.Such as, whether the testing result of judging nano microcrystalline CT output is greater than predefined current value; If determine that then the electric current in the circuit to be detected is big electric current; Otherwise, determine that the electric current in the circuit to be detected is little electric current.When the electric current in determining circuit to be detected is big electric current, adopt the testing result of Luo-coil output to carry out the judgement whether circuit to be detected breaks down; When the electric current in determining circuit to be detected is little electric current, adopt the testing result of nano microcrystalline CT output to carry out the judgement whether circuit to be detected breaks down.
In a word, adopt the technical scheme of the embodiment of the invention, can detect as carrying out current with high accuracy in the scope of 10A～3000A in a big way; And, because the binary channels current sensor senses scope in the embodiment of the invention is very wide, so the current sensor of the present invention of same model can be applicable among the MCCB ETU of a plurality of rated primary current grades, significantly reduce the current sensor model, and can significantly reduce the production cost of MCCB ETU manufacturer.In addition; the described binary channels current sensor of the embodiment of the invention has kept the advantage of existing CT; promptly; from the main protection circuit, power to MCCB ETU; and the characteristics of nano microcrystalline CT and Luo-coil itself also make binary channels current sensor of the present invention possess isolation and anti-interference function; concrete reason is known in this field, repeats no more.
Need to prove that the foregoing description only is used to illustrate, and is not limited to technical scheme of the present invention.Such as, the described binary channels current sensor of the embodiment of the invention is not only applicable among the MCCB ETU, and is equally applicable in the miscellaneous equipment of broad current detecting area requirement.In a word, all any modifications of being done within the spirit and principles in the present invention, be equal to and replace and improvement etc., all should be included within protection scope of the present invention.
Claims (9)
1, a kind of current sensing means comprises:
A current sensor, described current sensor comprises two sense channels, one of them described sense channel is applicable to big electric current is detected, another described sense channel is applicable to little electric current is detected that described two sense channels are used for respectively same electric current being detected and obtain testing result;
A measurement processor is used for selecting higher one of accuracy of detection to export as final detection result from the testing result of described two sense channels.
2, current sensing means according to claim 1 is characterized in that, the described sense channel that little electric current is detected that is applicable to adopts the nano microcrystalline current transformer.
3, current sensing means according to claim 1 is characterized in that, the described sense channel that big electric current is detected that is applicable to adopts Luo-coil.
4, current sensing means according to claim 1 is characterized in that, described measurement processor comprises:
A judging unit is used for the testing result and the predefined current value of one of them described sense channel are compared judgement;
A selected cell, be used in the testing result of described this sense channel of judgment unit judges during greater than described predefined current value, select the described testing result of the sense channel that big electric current is detected that is applicable to export as final detection result, during less than described predefined current value, select the described testing result of the sense channel that little electric current is detected that is applicable to export in the testing result of described this sense channel of judgment unit judges as final detection result.
5, a kind of electric current detecting method comprises:
Two sense channels are set respectively same electric current are detected and obtain testing result, wherein, a described sense channel is applicable to big electric current is detected that another described sense channel is applicable to little electric current is detected;
From the testing result of described two sense channels, select higher one of accuracy of detection to export as final detection result.
6, electric current detecting method according to claim 5 is characterized in that, the described sense channel that little electric current is detected that is applicable to adopts the nano microcrystalline current transformer.
7, electric current detecting method according to claim 5 is characterized in that, the described sense channel that big electric current is detected that is applicable to adopts Luo-coil.
8, electric current detecting method according to claim 5 is characterized in that, selects a higher step of exporting as final detection result of accuracy of detection to comprise from the testing result of described two sense channels:
The testing result of one of them sense channel is compared with predefined current value;
If the testing result of judging this sense channel greater than described predefined current value, is then exported the described testing result of the sense channel that big electric current is detected that is applicable to as final detection result;
Otherwise, the described testing result of the sense channel that little electric current is detected that is applicable to is exported as final detection result.
9, electric current detecting method according to claim 8 is characterized in that, the described sense channel that its testing result and predefined current value are compared is for adopting the sense channel of nano microcrystalline current transformer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA2008100032204A CN101498745A (en) | 2008-01-28 | 2008-01-28 | Current detecting device and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA2008100032204A CN101498745A (en) | 2008-01-28 | 2008-01-28 | Current detecting device and method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN101498745A true CN101498745A (en) | 2009-08-05 |
Family
ID=40945906
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA2008100032204A Pending CN101498745A (en) | 2008-01-28 | 2008-01-28 | Current detecting device and method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101498745A (en) |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102590587A (en) * | 2012-02-22 | 2012-07-18 | 西安交通大学 | Device and method for identifying short-circuit current of medium-voltage high-current direct current circuit breaker |
| CN102737917A (en) * | 2011-04-02 | 2012-10-17 | 三信国际电器上海有限公司 | Circuit breaker used for over-current protection |
| CN102749489A (en) * | 2011-04-20 | 2012-10-24 | 北京德威特继保自动化科技股份有限公司 | Signal sampling device and method |
| CN103185831A (en) * | 2011-12-30 | 2013-07-03 | 华东电力试验研究院有限公司 | Current detection method and device |
| CN104459279A (en) * | 2014-12-16 | 2015-03-25 | 上海斐讯数据通信技术有限公司 | Method for measuring wire current and electronic device |
| CN105259407A (en) * | 2015-11-04 | 2016-01-20 | 武汉精测电子技术股份有限公司 | Device and method for sampling and detection of multiple currents |
| CN105301336A (en) * | 2015-09-30 | 2016-02-03 | 安徽江淮汽车股份有限公司 | Two-channel current sensor-based signal acquisition and fault diagnosis method |
| CN106526270A (en) * | 2016-11-10 | 2017-03-22 | 上海华虹集成电路有限责任公司 | Measurement system |
| CN108781051A (en) * | 2016-03-07 | 2018-11-09 | 丹佛斯电力电子有限公司 | Method and apparatus for being characterized to three-phase induction motor |
| CN111122949A (en) * | 2020-01-15 | 2020-05-08 | 中北大学 | TMR and Rogowski coil composite current testing method |
| CN112122999A (en) * | 2020-09-21 | 2020-12-25 | 珠海格力电器股份有限公司 | Motor protection system and method |
| CN112986745A (en) * | 2021-04-30 | 2021-06-18 | 国家电网有限公司 | Load monitoring device integrating sampling and power supply energy taking and control method thereof |
-
2008
- 2008-01-28 CN CNA2008100032204A patent/CN101498745A/en active Pending
Cited By (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102737917A (en) * | 2011-04-02 | 2012-10-17 | 三信国际电器上海有限公司 | Circuit breaker used for over-current protection |
| CN102749489A (en) * | 2011-04-20 | 2012-10-24 | 北京德威特继保自动化科技股份有限公司 | Signal sampling device and method |
| CN103185831A (en) * | 2011-12-30 | 2013-07-03 | 华东电力试验研究院有限公司 | Current detection method and device |
| CN102590587A (en) * | 2012-02-22 | 2012-07-18 | 西安交通大学 | Device and method for identifying short-circuit current of medium-voltage high-current direct current circuit breaker |
| CN104459279A (en) * | 2014-12-16 | 2015-03-25 | 上海斐讯数据通信技术有限公司 | Method for measuring wire current and electronic device |
| CN105301336B (en) * | 2015-09-30 | 2018-07-10 | 安徽江淮汽车集团股份有限公司 | A kind of signal acquisition and fault judgment method based on binary channels current sensor |
| CN105301336A (en) * | 2015-09-30 | 2016-02-03 | 安徽江淮汽车股份有限公司 | Two-channel current sensor-based signal acquisition and fault diagnosis method |
| CN105259407A (en) * | 2015-11-04 | 2016-01-20 | 武汉精测电子技术股份有限公司 | Device and method for sampling and detection of multiple currents |
| CN108781051A (en) * | 2016-03-07 | 2018-11-09 | 丹佛斯电力电子有限公司 | Method and apparatus for being characterized to three-phase induction motor |
| CN108781051B (en) * | 2016-03-07 | 2021-10-22 | 丹佛斯电力电子有限公司 | Method and device for characterizing a three-phase induction machine |
| CN106526270A (en) * | 2016-11-10 | 2017-03-22 | 上海华虹集成电路有限责任公司 | Measurement system |
| CN111122949A (en) * | 2020-01-15 | 2020-05-08 | 中北大学 | TMR and Rogowski coil composite current testing method |
| CN111122949B (en) * | 2020-01-15 | 2021-12-03 | 中北大学 | TMR and Rogowski coil composite current testing method |
| CN112122999A (en) * | 2020-09-21 | 2020-12-25 | 珠海格力电器股份有限公司 | Motor protection system and method |
| CN112986745A (en) * | 2021-04-30 | 2021-06-18 | 国家电网有限公司 | Load monitoring device integrating sampling and power supply energy taking and control method thereof |
| CN112986745B (en) * | 2021-04-30 | 2022-08-26 | 国网安徽省电力有限公司马鞍山供电公司 | Load monitoring device integrating sampling and power supply energy taking and control method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101498745A (en) | Current detecting device and method | |
| CN102017380B (en) | Current detecting circuit and transformer current measuring system | |
| CN102818927B (en) | Measuring device and measuring method of reverse small current in direct current distribution system | |
| KR100882727B1 (en) | Apparatus for measuring current using rogowski sensor | |
| CN111650415B (en) | Self-powered current detection system and detection method for wide-current-band power transmission line | |
| Emanuel et al. | Current harmonics measurement by means of current transformers | |
| CN102866283A (en) | Superimposed large-current bias alternative-current (AC) current measuring device | |
| WO2017144715A1 (en) | Current sensor for a switch gear protection relay | |
| CN202305632U (en) | A Hall current sensor having double Hall elements and automobile power system adopting the Hall current sensor having the double Hall elements | |
| US5923514A (en) | Electronic trip circuit breaker with CMR current sensor | |
| CN102004513A (en) | Application of closed-loop Hall current sensor in high-energy big beam current ion implanter filament supply | |
| CN111257618A (en) | Cubical switchboard contact current measurement ring with from function of getting electricity | |
| CN202837368U (en) | AC measuring device superposed large DC bias | |
| CN102739066B (en) | Inductive current-to-voltage converter and method for measuring high frequency current | |
| CN115902726B (en) | Superconducting magnet coil quench detection method and device | |
| CN114935675A (en) | Electric energy meter and method for measuring current | |
| CN105957696B (en) | Current transformer for DC resistance measurement and preparation method thereof | |
| CN102004231A (en) | DC and low frequency magnetic field signal detection device and detection method thereof | |
| Qiu et al. | A fluxgate-based current sensor for DC bias elimination in a dual active bridge converter | |
| CN104749413A (en) | Current detection device and current detection method of electrostatic chuck power supply | |
| CN102881437A (en) | Current transformer for detecting aftercurrent, and aftercurrent protection device | |
| Park et al. | A new current measurement method in resistance spot welding | |
| CN101515027A (en) | Online detecting method for magnetic biasing of transformer core based on by-pass magnetic circuit | |
| CN201364356Y (en) | Cascade current sensor | |
| Pasterczyk et al. | Engineering illusion to accurately predict power losses in magnetic materials on the base of standard manufacturers' datasheets |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C12 | Rejection of a patent application after its publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20090805 |