CN106556733A - Hollow coil mutual inductance error cancelling method and the application of principle are offseted based on rotation - Google Patents
Hollow coil mutual inductance error cancelling method and the application of principle are offseted based on rotation Download PDFInfo
- Publication number
- CN106556733A CN106556733A CN201610983898.8A CN201610983898A CN106556733A CN 106556733 A CN106556733 A CN 106556733A CN 201610983898 A CN201610983898 A CN 201610983898A CN 106556733 A CN106556733 A CN 106556733A
- Authority
- CN
- China
- Prior art keywords
- hollow coil
- mutual inductance
- rotating disk
- rotation
- current
- 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.)
- Granted
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R35/00—Testing or calibrating of apparatus covered by the other groups of this subclass
- G01R35/02—Testing or calibrating of apparatus covered by the other groups of this subclass of auxiliary devices, e.g. of instrument transformers according to prescribed transformation ratio, phase angle, or wattage rating
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Measurement Of Resistance Or Impedance (AREA)
Abstract
The present invention disclose and offsets the hollow coil mutual inductance error cancelling method of principle based on rotation, including allowing the relative current carrying conductor of rotating disk to be rotated by 360 °/n, and measures the voltage of hollow coil, then with identical angle rotary turnplate and measures voltage, until rotating n time；Mutual inductance is obtained according to voltage and current value；Mutual inductance is weighted the mutual inductance exact value for averagely obtaining the hollow coil.The invention discloses hollow core coil current measuring method, mutual inductance is obtained using hollow coil mutual inductance error cancelling method, and with equal angular multiple rotary rotating disk, obtain the voltage of multigroup hollow coil, electric current is obtained according to mutual inductance and voltage, multigroup electric current weighting is averaged the exact value for obtaining tested electric current.The present invention on the premise of the factors such as hollow coil symmetry, current－carrying conductor section, tested current center position are unknown can weaken mutual inductance unstability, and can eliminate interference electric current impact, improve the accuracy of measurement of hollow coil.
Description
Technical field
The present invention relates to a kind of error cancelling method of current sensor, specifically, is related to offset principle based on rotation
Hollow coil mutual inductance error cancelling method and application.
Background technology
Hollow coil has the advantages that without magnetic saturation, measurement range is big, the linearity is good, bandwidth, is a kind of great competition
The New type of current sensor of power, hollow coil are a kind of inductance type transducers, realize the measurement to electric current, mutual inductance based on magnetic induction
Coefficient is its most critical parameters.
In hollow coil, Secondary Winding is wound on a non magnetic skeleton, there is no ferromagnetic material, makes sensor in several peaces
Still have in the range of hundreds of kilo-ampere it is excellent linear, it is different from traditional CT, as it is not direct measurement electric current, even if
Tested electric current contains very big DC component, still will not saturation.Therefore in recent years air-core current transformer start to be applied to after
In electric protection and measurement.
The current carrying conductor that stream has tested electric current is placed in by whole coil uniformly around on an annular non magnetic skeleton
In the annular nonmagnetic skeleton of hollow coil, and the diameter parallel of logical annular nonmagnetic skeleton, for the sinusoidal current under stable state,
The output voltage of hollow coil can be expressed as e=Mj ω I, and in formula, I is tested electric current, and M is mutual inductance constant, and ω is for just
The angular frequency of string electric current, output voltages of the e for air core coil.
General hollow coil needs to match integrator and uses (include analogue integrator and digital integrator), integrator it is defeated
Enter output voltage signal and meet relational expression Uo=KUi/ (j ω), wherein UiFor input voltage signal, UoFor output voltage signal,
Angular frequencies of the ω for sinusoidal current.If using the output voltage of hollow coil as integrator input signal, final output
Voltage Uo=KMI.Can see, the accuracy of the tested electric current of measurement of hollow coil depends on a stable mutual inductance system
Number M.So in order to obtain high-precision hollow coil, following principle is must comply with during making：Loop density is constant；Skeleton section
Product is constant；Coil section and central axis, otherwise, can cause hollow coil structure asymmetric, be introduced into larger measurement
Error.
Actual production and application in, in order to avoid hollow coil structure it is asymmetric and introduce measurement error, by mark
Determine electric current to demarcate hollow coil mutual inductance, but the mutual inductance M for demarcating every time is unlikely to be completely constant, carries
The shape of conductance line, position and CURRENT DISTRIBUTION have direct and significant impact to the mutual inductance M for demarcating, and error is usually
1% -3%, extreme case can exceed that 10%, and such accuracy can not meet the current measurement of most of industry spot will
Ask, this is also to hinder one of major reason of hollow coil industrialization.
Based on this, in the urgent need to a kind of mutual inductance error cancelling method of hollow coil, to solve using present in
The problems referred to above, greatly improve the accuracy of measurement of hollow coil, meet the measurement demand of most industry spot.
The content of the invention
For drawbacks described above, the invention provides the hollow coil mutual inductance error concealment side of principle is offseted based on rotation
Method, it is intended to solve in prior art due to during hollow coil mutual inductance is demarcated hollow coil structure not to property and current-carrying
The impact of wire shape, position and CURRENT DISTRIBUTION factor to the mutual inductance of hollow coil and make the inaccurate technology of calibration result
Problem.
For achieving the above object, the hollow coil mutual inductance error concealment that principle is offseted based on rotation that the present invention is provided
Method, hollow coil are fixed on rotating disk, and hollow coil central axis is overlapped with center of turntable axis, and current carrying conductor is placed in and turns
It is in disk and parallel with center of turntable axis, it is characterised in that to comprise the steps：
(1) rotating disk is allowed to rotate relative to current carrying conductorAnd measure the voltage e of hollow coil after the rotation of rotating disk i ＆ lti；
(2) judge whether turntable rotation order i is equal to turntable rotation frequency n, if then entering step (3), otherwise, i=i
+ 1 and enter step (1)；
(3) hollow coil after the rotation of rotating disk i ＆ lt is obtained according to Calibrated current in the voltage and current carrying conductor of hollow coil
The measured value M of mutual inductancei；
(4) measured value of hollow coil mutual inductance after the rotation of rotating disk i ＆ lt is weighted into acquisition hollow coil of averaging
Elimination error after mutual inductance M；
In formula, i is turntable rotation order, and the initial value of i is turntable rotation when 1, n eliminates error mutual inductance to obtain
Number, and 1≤i≤n, eiFor the voltage of hollow coil after the rotation of rotating disk i ＆ lt, MiFor hollow coil mutual inductance after the rotation of rotating disk i ＆ lt
The measured value of coefficient, the mutual inductance after the elimination error of M hollow coils.
By multiple rotary rotating disk, and the anglec of rotation is identical every time, is obtained in rotating disk and load after rotating disk of every rotation
The voltage of conductance line hollow coil under the position, and mutual inductance system is converted into according to hollow coil voltage and Calibrated current relation
Number, the error of the corresponding mutual inductance of each rotary turnplate are different, due to each anglec of rotation it is identical so that these errors
Normal Distribution rule, multiple mutual inductance is weighted averagely, you can eliminate the error of mutual inductance, i.e., using rotation
Turn to offset the error that principle eliminates mutual inductance, so as to greatly lift the class of accuracy of hollow core coil current measurement.
Further, according to formula in step (3)Obtain hollow coil mutual inductance system after the rotation of rotating disk i ＆ lt
Several measured value Mi；In formula, eiFor the voltage of hollow coil after the rotation of rotating disk i ＆ lt, MiFor hollow line after the rotation of rotating disk i ＆ lt
The measured value of circle mutual inductance, ω are the angular frequency of Calibrated current in current carrying conductor, and j is imaginary unit, IPFor in current carrying conductor
Calibrated current, i are turntable rotation order.
Further, according to formula in step (4)The mutual inductance M of the hollow coil is obtained, in formula, M is
Hollow coil eliminates the mutual inductance after error, MiFor the measured value of hollow coil mutual inductance after the rotation of rotating disk i ＆ lt, i is
Turntable rotation order, turntable rotation number of times when the initial value of i eliminates error mutual inductance to obtain for 1, n, and 1≤i≤n.
Further, angle mark is done on above-mentioned rotating disk, be easy to exactly according to equal angular rotary turnplate.
Further, manually, electric power or other automatization's modes realize rotating disk and current carrying conductor relative position
Change.
Further, the species of the hollow coil is that winding by hand formula, machine be wound and PCB formulas.
As another aspect of the present invention, the invention provides a kind of method that hollow coil measures electric current, including it is as follows
Step：
(1) obtain hollow coil using the hollow coil mutual inductance error cancelling method described in claim 1 to eliminate
Mutual inductance M after error；
(2) Calibrated current in current carrying conductor is replaced with tested electric current, allow rotating disk to rotate relative to current carrying conductorAnd obtain
The voltage e of hollow coil after rotating disk kth time rotates when measuring tested electric currentk；
(3) when judging to measure tested electric current, whether turntable rotation order k is equal to rotating disk number of revolutions when measuring tested electric current
M, if then entering step (4), otherwise, k=k+1 and entering step (2)；
(4) eliminate mutual after error according to hollow coil voltage after rotating disk kth time when measuring tested electric current and hollow coil
Sense coefficient obtains tested current measurement value I after the secondary rotation of rotating disk kth when measuring tested electric currentk；
(5) tested current measurement value I after rotating disk kth time rotation when will measure tested electric currentkIt is weighted average acquisition quilt
Survey electric current exact value I；
In formula, M represents that obtaining hollow coil with hollow coil mutual inductance error cancelling method eliminates mutual inductance system after error
Count, rotating disk rotation order when k is measurement tested electric current, turntable rotation number of times when k initial values are the tested electric current of measurement for 1, m, and 1
≤ k≤m, ekRepresent the voltage of hollow coil after the rotation of rotating disk kth time when measuring tested electric current, IkWhen representing the tested electric current of measurement
Tested current measurement value after rotating disk kth time rotation, the exact value of the tested electric currents of I.
Further, also including integrator, for hollow coil output voltage is integrated process so that integrator is defeated
Go out voltage proportional with tested electric current, integrator input is connected with hollow coil outfan.
Further, according to formula in step (4)Obtain the quilt that the rotating disk when tested electric current is measured rotates k time
Survey current measurement value Ik；In formula, M represents that obtaining hollow coil with hollow coil mutual inductance error cancelling method eliminates after error
Mutual inductance, IkTested current measurement value after the rotation of rotating disk kth time when representing measurement tested electric current, T is the integrator
Amplification coefficient, EkThe output voltage of integrator after the rotation of rotating disk kth time when measuring tested electric current is represented, k is the tested electric current of measurement
When rotating disk rotate order.
By the contemplated above technical scheme of the present invention, compared with prior art, following beneficial effect can be obtained：
1st, it is of the invention by hollow coil is fixed on rotating disk, and the central axis of hollow coil and center of turntable axis
Overlap, realize changing the relative position of hollow coil and current carrying conductor with identical angular turn rotating disk every time, often change once
Relative position carries out the measurement of voltage in a hollow coil, according to the hollow line that voltage in the hollow coil of each measurement is obtained
There is error in the mutual inductance of circle, these errors are due to the unsymmetry of loop construction, current carrying conductor position, shape and electricity
The interference of flow distribution and external interference electric current and magnetic field causes, but due to each rotating disk rotational angle it is identical, and every time angle
ForSo that be in normal distribution by the mutual inductance error that measurement voltage is obtained every time, by all mutual inductances are added
Weigh the theoretical mutual inductance for obtaining that mutual inductance is hollow coil of averaging.
2nd, the present invention proposes the method that hollow coil measures electric current, carries out repeatedly according to Calibrated current and by rotary turnplate
Measurement hollow coil voltage simultaneously takes weighted mean, obtains the mutual inductance after hollow coil eliminates error, empty further according to obtaining
Core coil eliminates the mutual inductance after error and repeatedly measures the hollow coil voltage multiple tested electric currents of acquisition by rotary turnplate
Value, and tested current value is taken into weighted mean, obtain tested current value exact value.The present invention is in hollow coil winding symmetry shape
On the premise of the key influence factors such as condition, current－carrying conductor section, tested current center position are unknown, on the one hand greatly can weaken
The unstability of hollow coil mutual inductance, is on the other hand completely eliminated the impact of external interference electric current, so as to significantly improve
The accuracy of measurement of hollow coil, to adapt to industry spot current measurement demand.
Description of the drawings
Fig. 1 is the hollow coil mutual inductance error cancelling method and reality that principle is offseted based on rotation provided by the present invention
The schematic diagram of current methods institute use device is measured with hollow coil；
The flow process of the hollow coil mutual inductance error cancelling method that principle is offseted based on rotation that Fig. 2 is provided for the present invention
Figure；
The hollow core coil of hollow coil mutual inductance error cancelling method and electric current relative position that Fig. 3 is provided for the present invention
Figure；
Phases of the Fig. 4 for interference electric current in the hollow coil mutual inductance error cancelling method that provides of the present invention and hollow coil
To the location drawing.
Specific embodiment
In order that the objects, technical solutions and advantages of the present invention become more apparent, it is below in conjunction with drawings and Examples, right
The present invention is further elaborated.It should be appreciated that specific embodiment described herein is only to explain the present invention, and
It is not used in the restriction present invention.
As shown in figure 1, the hollow coil mutual inductance error concealment side that principle is offseted based on rotation provided by the present invention
Method and using hollow coil measurement current methods institute use device, including rotating disk 1, hollow coil 2 and current－carrying conductor 3, hollow
Coil 2 is tightly fastened on the turntable 1, rotating disk 1 can uniformly continuous rotate along central axis 4, the size and hollow coil of rotating disk 1
2 size matching, and the central axes of 1 central axis 4 of rotating disk and hollow coil 2, if obtain eliminating hollow line after error
Circle mutual inductance, flows through Calibrated current 6 in current carrying conductor 3, if obtaining tested electric current exact value, current-carrying conductor using hollow coil
Tested electric current 6 is flow through in 3, current－carrying conductor 3 is located at the inside of rotating disk 1, and parallel with the central axis 4 of rotating disk 1.
As shown in Fig. 2 the hollow coil mutual inductance error concealment side that principle is offseted based on rotation provided by the present invention
Method, comprises the steps：
(1) rotating disk is allowed to rotate relative to current carrying conductorAnd measure the voltage e of hollow coil after the rotation of rotating disk i ＆ lti, i
For turntable rotation order, turntable rotation number of times when the initial value of i eliminates error mutual inductance to obtain for 1, n, and 1≤i≤n.
(2) judge whether turntable rotation order i is equal to turntable rotation frequency n, if then entering step (3), otherwise, i=i
+ 1 and enter step (1).
By every time with identical angle rotary turnplate 1, and keep 3 position of current carrying conductor constant, change rotary turnplate 1 with
The relative position of current carrying conductor 3, obtains the voltage of hollow coil 2 under the relative position, often in relative position of every change
The angle of secondary rotation is changeable, is determined by actual condition, but the angle of rotation is uniform equal every time, is 360 °/n, wherein n
For the number of times that rotating disk is rotated, the rotation of rotating disk strictly will be coordinated in sequential with the measurement of electric current.
(3) hollow coil after the rotation of rotating disk i ＆ lt is obtained according to Calibrated current in the voltage and current carrying conductor of hollow coil
The measured value M of mutual inductancei。
According to formula in step (3)Obtain the measurement of hollow coil mutual inductance after rotating disk i ＆ lt rotates
Value Mi；In formula, eiFor the voltage of hollow coil after the rotation of rotating disk i ＆ lt, MiFor hollow coil mutual inductance system after the rotation of rotating disk i ＆ lt
Several measured values, ω are the angular frequency of Calibrated current in current carrying conductor, and j is imaginary unit, IPFor Calibrated current in current carrying conductor,
I is turntable rotation order.
(4) measured value of hollow coil mutual inductance after the rotation of rotating disk i ＆ lt is weighted into acquisition hollow coil of averaging
Elimination error after mutual inductance M.
By according to equal angular rotary turnplate, taking multiple measurements voltage in hollow coil, obtain multiple mutual inductance systems and survey
Value, the error of each mutual inductance measured value are different, but as each anglec of rotation is identical, and the anglec of rotation is
360 °/n so that the error Normal Distribution rule of mutual inductance measured value, the weighting of mutual inductance measured value is averaged, i.e.,
The error of mutual inductance measured value can be eliminated.
In order that rotating disk rotates identical angle every time, angle is identified on rotating disk.Rotating disk reality can manually be rotated
The change of existing rotating disk and current carrying conductor relative position.In rotation process, rotating disk must be smooth, will be maintained in rotary course
In fixed horizontal plane, must not significantly vibrate or rock.
The change of rotating disk and current carrying conductor relative position, the party can also be realized by electric power or other automatization's modes
Can realize continuously measuring voltage in hollow coil under formula, that is, make n level off to infinity, can effectively reduce mutual inductance system
Several errors.
The hollow coil mutual inductance error cancelling method provided in the present invention does not overturn the principle of existing hollow coil,
It can be applied to the hollow coil of nearly all structure, including winding by hand formula, machine be wound and PCB formulas, and hollow coil is along coil
Axis constantly rotates, and its objective is to eliminate the uncertainty of mutual inductance error, and the meansigma methodss that diverse location is repeatedly measured can increase
The stability of strong mutual inductance.
CURRENT DISTRIBUTION pair in the relative position of current－carrying conductor and hollow coil, current carrying conductor cross sectional shape and current carrying conductor
Mutual inductance has a direct impact, and may certify that by the law of electromagnetic induction：When current center position and hollow coil central axis
During coincidence, mutual inductance is M0, it is the theoretical mutual inductance of the hollow coil；When actual current is measured, current center position
Put and can not possibly be completely superposed with hollow coil central axis, the deviation of mutual inductance will produce very big error in electric current.Such as
Shown in Fig. 3, if current center position is in 5-1 positions, corresponding mutual inductance is M1, mutual inductance measured value M1With theory
Mutual inductance M0It is usually unequal.In constantly rotation hollow coil 2, according to motion composition, current center position
5-2,5-3,5-4 ..., 5-n are reached successively, and corresponding mutual inductance is respectively M2、M3、M4、…、Mn.When rotating disk i ＆ lt rotates
The magnetic induction that electric current is produced in hollow coil is：
In formula, I is electric current, diameters of the R for hollow coil, r1For current center apart from hollow coil central shaft distance,I refers to that rotating disk rotates order, 1≤i≤n, r1＜ R.
The magnetic induction that rotating disk i ＆ lt rotatory current is produced in hollow coil is averaged, formula is：
As can be seen that when rotating disk number of revolutions n is sufficiently large, circuit center is being r apart from hollow coil central axis1's
On circle, the meansigma methodss of the magnetic induction that any point is produced in being in hollow coil are in hollow coil axial location with electric current
Electromagnetic intensity is produced in hollow coil identical, therefore we can obtain drawing a conclusion：Although M1、M2、M3、…、MnWith
M0There is relatively large deviation, but when n is sufficiently large, M1、M2、M3、…、MnMeansigma methodss be to be equal to M0's.
As shown in figure 4, there is interference electric current 7 outside window in hollow coil 2, between them, there is certain magnetic coupling, it is equivalent
Mutual inductance can not possibly be equal to zero, therefore, external interference current magnetic field can be produced not to the accuracy of measurement of hollow coil 2
Predictable appreciable impact.If interference current center position is in 7-1, corresponding mutual inductance is M '1, in constantly rotation hollow
During coil 2, according to motion composition, the relative position of hollow coil 2 and interference electric current center is as shown in figure 4, interference
Current center position reaches 7-2,7-3 ..., 7-n successively, and corresponding mutual inductance is respectively M '1M′2…、M′n, when rotating disk i ＆ lt
The magnetic induction that interference electric current is produced in hollow coil during rotation is：
In formula, I' is interference electric current, diameters of the R for hollow coil, r2For interference electric current centre distance hollow coil center
The distance of axle,I refers to that rotating disk rotates order, 1≤i≤n, r2＞ R.
As can be seen that when n convergences are infinite, interference electric current is being r apart from hollow coil axis2On circle, any point is in sky
The meansigma methodss of the magnetic induction produced in core coil are equal to zero, therefore can obtain as drawn a conclusion：When n is sufficiently large, M '1、
M′2、…、M′nMeansigma methodss always equal to 0, external interference electric current 7 pairs is completely eliminated by the method for the multiple measurement of rotation
The impact of hollow coil 2.
In the same manner, by repeatedly with identical angle rotary turnplate, and the angle for rotating every time isSo that due to hollow
The error of the asymmetric mutual inductance measured value for causing of loop construction is in normal distribution, after the weighting of mutual inductance error is averaged
It is zero.
In sum, due to hollow coil structural asymmetry, the impact of interference electric current and current carrying conductor shape, position and
CURRENT DISTRIBUTION factor causes the error of the mutual inductance measured value of hollow coil in normal distribution, by by obtained mutual inductance
Measured value takes weighted average and obtains the mutual inductance after hollow coil eliminates error.
Can be according to formula in step (4)Obtain mutual inductance exact value M of the hollow coil；Can also
It is used to eliminate random error using more complicated numerical computation method, the selection of algorithm has very high point with the value of pendulous frequency n
System.
The method of the hollow coil measurement electric current that the present invention is provided is measured using device as shown in Figure 1, including such as
Lower step：
(1) hollow coil is obtained using hollow coil mutual inductance error cancelling method and eliminates the mutual inductance M after error,
Comprise the steps：
(11) rotating disk is allowed to rotate relative to current carrying conductorAnd measure the voltage e of hollow coil after the rotation of rotating disk i ＆ lti,
I is turntable rotation order, and it is to obtain turntable rotation number of times when eliminating the mutual inductance of error that the initial value of i is 1, n, and 1≤i≤
n；
(12) judge whether turntable rotation order i is equal to turntable rotation frequency n, if then entering step (13), otherwise, i
=i+1 simultaneously enters step (11)；
(13) according to formulaObtain the measured value M of hollow coil mutual inductance after rotating disk i ＆ lt rotatesi；
In formula, eiFor the voltage of hollow coil after the rotation of rotating disk i ＆ lt, MiFor hollow coil mutual inductance after the rotation of rotating disk i ＆ lt
The measured value of coefficient, ω are the angular frequency of Calibrated current in current carrying conductor, and j is imaginary unit, IPFor electricity is demarcated in current carrying conductor
Stream, i are turntable rotation order；
(14) measured value of hollow coil mutual inductance after the rotation of rotating disk i ＆ lt is taken into weighted mean and obtains hollow coil
Eliminate the mutual inductance M after error.
(2) Calibrated current in current carrying conductor is replaced with tested electric current, allow rotating disk to rotate relative to current carrying conductorAnd obtain
The voltage e of hollow coil after rotating disk kth time rotates when measuring tested electric currentk, when k is to measure tested electric current, rotating disk rotates order, k
Initial value is 1, and 1≤k≤m, m are turntable rotation number of times when measuring tested electric current.
(3) when judging to measure tested electric current, whether turntable rotation order k is equal to rotating disk number of revolutions when measuring tested electric current
M, if then entering step (4), otherwise, k=k+1 and entering step (2).
(4) eliminated after error according to hollow coil voltage after rotating disk kth time rotation when measuring tested electric current and hollow coil
Mutual inductance obtain when measuring tested electric current tested current measurement value I after rotating disk kth time rotationk；
(5) current measurement value I after rotating disk kth time rotation when will measure tested electric currentkIt is weighted
Stream exact value I.
In the embodiment of the method for the hollow coil measurement electric current that the present invention is provided, using following measurement device：
Hollow coil is fixed on rotating disk, and hollow coil central axis is overlapped with center of turntable axis, current carrying conductor
It is in rotating disk and parallel with center of turntable axis, tested electric current, outfan and the integration of hollow coil are passed through in current carrying conductor
The input connection of device, the voltage that hollow coil export is integrated processs by integrator so that voltage that integrator is exported and
In current carrying conductor, tested voltage is proportional.
Comprise the steps in above-described embodiment：
(1) hollow coil is obtained using hollow coil mutual inductance error cancelling method and eliminates the mutual inductance M after error,
Comprise the steps：
(11) rotating disk is allowed to rotate relative to current carrying conductorAnd measure the voltage e of hollow coil after the rotation of rotating disk i ＆ lti,
I is turntable rotation order, turntable rotation number of times when the initial value of i eliminates error mutual inductance to obtain for 1, n, and 1≤i≤n；
(12) judge whether turntable rotation order i is equal to turntable rotation frequency n, if then entering step (13), otherwise, i
=i+1 simultaneously enters step (11)；
(13) according to formulaObtain the measured value M of hollow coil mutual inductance after rotating disk i ＆ lt rotatesi；
In formula, eiFor the voltage of hollow coil after the rotation of rotating disk i ＆ lt, MiFor hollow coil mutual inductance after the rotation of rotating disk i ＆ lt
The measured value of coefficient, ω are the angular frequency of Calibrated current in current carrying conductor, and j is imaginary unit, IPFor electricity is demarcated in current carrying conductor
Stream, i are turntable rotation order；
(14) the measured value weighted mean of hollow coil mutual inductance after the rotation of rotating disk i ＆ lt is obtained into hollow coil
Eliminate mutual inductance M after error.
(2) Calibrated current in current carrying conductor is replaced with tested electric current, allow rotating disk to rotate relative to current carrying conductorAnd obtain
Integrator output voltage E after rotating disk kth time rotation when measuring tested electric currentk, when k is to measure tested electric current, rotating disk rotates order, k
Initial value is 1, and 1≤k≤m, m are turntable rotation number of times when measuring tested electric current.
(3) when judging to measure tested electric current, whether turntable rotation order k is equal to rotating disk number of revolutions when measuring tested electric current
M, if then entering step (4), otherwise, k=k+1 and entering step (2).
(4) according to formulaObtain the tested current measurement value I that the rotating disk when tested electric current is measured rotates k timek；
In formula, M represents that obtaining hollow coil with hollow coil mutual inductance error cancelling method eliminates the mutual inductance after error
Coefficient, IkTested current measurement value in current carrying conductor after rotating disk kth time rotates when representing measurement tested electric current, T are integrator
Amplification coefficient, EkThe output voltage of integrator after the rotation of rotating disk kth time when measuring tested electric current is represented, k is the tested electric current of measurement
When rotating disk rotate order.
(5) tested current measurement value I after rotating disk kth time rotation when will measure tested electric currentkIt is weighted average acquisition quilt
Survey electric current exact value I.
The present invention proposes the method that hollow coil measures electric current, carries out repeatedly according to Calibrated current value and by rotary turnplate
Measurement hollow coil voltage simultaneously takes weighted mean, obtains the mutual inductance after hollow coil eliminates error, empty further according to obtaining
Core coil eliminate error after mutual inductance and hollow coil voltage is repeatedly measured by rotary turnplate and weighted mean is taken, obtain
Obtain tested current value exact value so that the method for hollow coil measurement electric current proposed by the present invention is in hollow coil winding symmetry shape
On the premise of the key influence factors such as condition, current－carrying conductor section, tested current center position are unknown, on the one hand greatly can weaken
The unstability of hollow coil mutual inductance, is on the other hand completely eliminated the impact of external interference electric current, so as to significantly improve
The accuracy of measurement of hollow coil, to adapt to industry spot current measurement demand.
As it will be easily appreciated by one skilled in the art that the foregoing is only presently preferred embodiments of the present invention, not to
The present invention, all any modification, equivalent and improvement made within the spirit and principles in the present invention etc. are limited, all should be included
Within protection scope of the present invention.
Claims (9)
1. a kind of to offset the hollow coil mutual inductance error cancelling method of principle based on rotation, hollow coil is fixed on rotating disk
On, and hollow coil central axis overlapped with center of turntable axis, current carrying conductor is placed in rotating disk and flat with center of turntable axis
OK, it is characterised in that comprise the steps：
(1) rotating disk is allowed to rotate relative to current carrying conductorAnd measure the voltage e of hollow coil after the rotation of rotating disk i ＆ lti；
(2) judge whether turntable rotation order i is equal to turntable rotation frequency n, if then entering step (3), otherwise, i=i+1 is simultaneously
Into step (1)；
(3) hollow coil after the rotation of rotating disk i ＆ lt is obtained according to Calibrated current in the voltage and current carrying conductor of the hollow coil
The measured value M of mutual inductancei；
(4) the measured value weighting of hollow coil mutual inductance after rotating disk i ＆ lt rotation is taken into average acquisition hollow coil
Eliminate mutual inductance M after error；
In formula, i is turntable rotation order, and when the initial value of i is the mutual inductance that 1, n is acquisition elimination error, turntable rotation is secondary
Number, and 1≤i≤n, eiFor the voltage of hollow coil after the rotation of rotating disk i ＆ lt, MiFor hollow coil mutual inductance after the rotation of rotating disk i ＆ lt
The measured value of coefficient, M are the mutual inductance after hollow coil eliminates error.
2. hollow coil mutual inductance error cancelling method according to claim 1, it is characterised in that the step (3)
It is middle according to formulaObtain the measured value M of hollow coil mutual inductance after rotating disk i ＆ lt rotatesi；In formula, eiTo turn
The voltage of hollow coil, M after the rotation of disk i ＆ ltiFor the measured value of hollow coil mutual inductance after the rotation of rotating disk i ＆ lt, ω is
The angular frequency of Calibrated current in current carrying conductor, j is imaginary unit, IPFor Calibrated current in current carrying conductor, i is turntable rotation
Sequence.
3. hollow coil mutual inductance error cancelling method according to claim 1, it is characterised in that the step (4)
It is middle according to formulaThe mutual inductance M of the hollow coil is obtained, in formula, M is the mutual inductance after hollow coil eliminates error
Coefficient, MiFor the measured value of hollow coil mutual inductance after the rotation of rotating disk i ＆ lt, i is turntable rotation order, and the initial value of i is
1, n is to obtain turntable rotation number of times when eliminating error mutual inductance, and 1≤i≤n.
4. hollow coil mutual inductance error cancelling method according to any one of claim 1 to 3, it is characterised in that
Angle mark is done on the rotating disk.
5. hollow coil mutual inductance error cancelling method according to any one of claim 1 to 3, it is characterised in that
Manually, electric power or other automatization's modes realize the change of rotating disk and current carrying conductor relative position.
6. hollow coil mutual inductance error cancelling method according to any one of claim 1 to 3, it is characterised in that
The species of the hollow coil is winding by hand formula, machine is wound and PCB formulas.
7. it is a kind of with hollow coil measure electric current method, it is characterised in that comprise the steps：
(1) elimination for obtaining hollow coil using the hollow coil mutual inductance error cancelling method described in claim 1 is missed
The mutual inductance M of after the recovery；
(2) Calibrated current in current carrying conductor is replaced with tested electric current, allow rotating disk to rotate relative to current carrying conductorAnd obtain measurement
The voltage e of hollow coil after rotating disk kth time rotates during tested electric currentk；
(3) when judging to measure tested electric current, whether turntable rotation order k is equal to rotating disk number of revolutions m when measuring tested electric current, if
It is then to enter step (4), otherwise, k=k+1 and enter step (2)；
(4) according to mutual after the elimination error of hollow coil voltage and hollow coil after rotating disk kth time rotation when measuring tested electric current
Sense coefficient obtains tested current measurement value I after the secondary rotation of rotating disk kth when measuring tested electric currentk；
(5) tested current measurement value I after rotating disk kth time rotation when will measure tested electric currentkIt is weighted
Exact value I；
In formula, M represents that obtaining hollow coil with hollow coil mutual inductance error cancelling method eliminates mutual inductance after error, k
During to measure tested electric current, rotating disk rotates order, turntable rotation number of times when k initial values are the tested electric current of measurement for 1, m, and 1≤k
≤ m, ekRepresent the voltage of hollow coil after the rotation of rotating disk kth time when measuring tested electric current, IkRotating disk when representing measurement tested electric current
Tested current measurement value after kth time rotation, the exact value of the tested electric currents of I.
8. the method for measuring electric current according to the hollow coil described in claim 7, it is characterised in that also including integrator, uses
In hollow coil output voltage is integrated process so that integrator output voltage is proportional with tested electric current, the integration
Device input is connected with the hollow coil outfan.
9. according to the method for measuring electric current with hollow coil described in claim 8, it is characterised in that in the step (4)
According to formulaObtain tested current measurement value I after the secondary rotation of the rotating disk kth when tested electric current is measuredk；In formula, M tables
Showing, hollow coil is obtained with hollow coil mutual inductance error cancelling method eliminates mutual inductance after error, IkRepresent that measurement is tested
Tested current measurement value in current carrying conductor after rotating disk kth time rotation during electric current, T is the amplification coefficient of the integrator, EkRepresent
The integrator output voltage after rotating disk kth time rotation, rotating disk rotation time when k is to measure tested electric current when measuring tested electric current
Sequence.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610983898.8A CN106556733B (en) | 2016-11-09 | 2016-11-09 | Hollow coil mutual inductance error cancelling method and the application of principle are offseted based on rotation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610983898.8A CN106556733B (en) | 2016-11-09 | 2016-11-09 | Hollow coil mutual inductance error cancelling method and the application of principle are offseted based on rotation |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106556733A true CN106556733A (en) | 2017-04-05 |
| CN106556733B CN106556733B (en) | 2017-09-01 |
Family
ID=58444757
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610983898.8A Active CN106556733B (en) | 2016-11-09 | 2016-11-09 | Hollow coil mutual inductance error cancelling method and the application of principle are offseted based on rotation |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106556733B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108362925A (en) * | 2018-02-22 | 2018-08-03 | 西安交通大学 | The Zero flux checking of great current system and method for double figure of eight three wires magnetic field cancellations |
| CN108594151A (en) * | 2018-06-02 | 2018-09-28 | 福州大学 | Positional error compensation method without magnetic core current sensor |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101216542A (en) * | 2007-01-06 | 2008-07-09 | 赵化宾 | Current detecting device and calibration method |
| EP1956384A2 (en) * | 2007-02-08 | 2008-08-13 | Vacuumschmelze GmbH & Co. KG | Current sensor device |
| CN203689783U (en) * | 2013-12-31 | 2014-07-02 | 杭州精科仪器有限公司 | Coil mutual inductance detection experimental device |
| CN105572451A (en) * | 2014-10-29 | 2016-05-11 | 施耐德电气美国股份有限公司 | Self-correcting current transformer system |
| US20160320434A1 (en) * | 2013-10-09 | 2016-11-03 | Abb Research Ltd. | Current measurement device and method using a rogowski type current transducer |
-
2016
- 2016-11-09 CN CN201610983898.8A patent/CN106556733B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101216542A (en) * | 2007-01-06 | 2008-07-09 | 赵化宾 | Current detecting device and calibration method |
| EP1956384A2 (en) * | 2007-02-08 | 2008-08-13 | Vacuumschmelze GmbH & Co. KG | Current sensor device |
| US20160320434A1 (en) * | 2013-10-09 | 2016-11-03 | Abb Research Ltd. | Current measurement device and method using a rogowski type current transducer |
| CN203689783U (en) * | 2013-12-31 | 2014-07-02 | 杭州精科仪器有限公司 | Coil mutual inductance detection experimental device |
| CN105572451A (en) * | 2014-10-29 | 2016-05-11 | 施耐德电气美国股份有限公司 | Self-correcting current transformer system |
Non-Patent Citations (1)
| Title |
|---|
| 李振华等: "基于空心线圈互感系数自校验原理的大电流校验系统", 《高电压技术》 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108362925A (en) * | 2018-02-22 | 2018-08-03 | 西安交通大学 | The Zero flux checking of great current system and method for double figure of eight three wires magnetic field cancellations |
| CN108362925B (en) * | 2018-02-22 | 2020-03-17 | 西安交通大学 | Zero-flux large-current detection system and method for magnetic field cancellation of double-8-shaped three-wire |
| CN108594151A (en) * | 2018-06-02 | 2018-09-28 | 福州大学 | Positional error compensation method without magnetic core current sensor |
| CN108594151B (en) * | 2018-06-02 | 2019-11-12 | 福州大学 | Positional error compensation method without magnetic core current sensor |
Also Published As
| Publication number | Publication date |
|---|---|
| CN106556733B (en) | 2017-09-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10139432B2 (en) | Methods and systems relating to improved AC signal performance of dual stage transformers | |
| CN102565728B (en) | Method for measuring magnetic permeability of cylindrical soft magnetic material | |
| CN112834805A (en) | Tunneling magnetic resistance current sensor with position error calibration function and calibration method | |
| CN102087903A (en) | Double-face symmetric wired printed circuit board (PCB) type Rogowski coil | |
| CN103630724B (en) | Based on the self calibration harmonic current mutual inductor of band gap iron-core coil | |
| CN106556733B (en) | Hollow coil mutual inductance error cancelling method and the application of principle are offseted based on rotation | |
| CN104101785B (en) | A kind of four-end method high level condensance measurement apparatus and its measuring method | |
| CN111880123B (en) | Method for detecting frequency response signal of transformer winding resisting power frequency magnetic saturation | |
| CN107271933A (en) | A kind of axis fluxgate sensor of spherical three | |
| CN112362941A (en) | Annular current transformer and method for measuring current by using same | |
| CN104730342B (en) | The measuring circuit and measuring method of AC resistance time constant | |
| WO2021088200A1 (en) | Dual-stage magnetic excitation high-voltage proportional standard apparatus and error compensation method | |
| CN113517122B (en) | PCB type current transformer with correction function | |
| CN206161723U (en) | Hollow coil mutual inductance's error concealment device and current measuring device | |
| CN108427085A (en) | A method of measuring magnetic material magnetization characteristic | |
| CN203606413U (en) | High-accuracy electronic compensation type current transformer | |
| CN107607893B (en) | A kind of design method of high flat degree medium-high magnetic field measuring coil | |
| CN106291431B (en) | A kind of tracking accuracy measurement method of current sensor | |
| CN108226610A (en) | A kind of clamp measuring device for alternating current-direct current low current | |
| CN213069016U (en) | Annular coil structure for magnetic core parameter measurement | |
| CN112730944B (en) | Current measuring method and device based on Rogowski coil | |
| Sesé et al. | Ultimate current resolution of a cryogenic current comparator | |
| CN106526302A (en) | Method for manufacturing high-performance air-core coil with balanced turns | |
| CN208140774U (en) | A kind of clamp measuring device for alternating current-direct current low current | |
| CN207571188U (en) | A kind of direct current measuring devices |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |