CN104297706B - A kind of field generator for magnetic and its method for designing based on resonance - Google Patents
A kind of field generator for magnetic and its method for designing based on resonance Download PDFInfo
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- CN104297706B CN104297706B CN201410553325.2A CN201410553325A CN104297706B CN 104297706 B CN104297706 B CN 104297706B CN 201410553325 A CN201410553325 A CN 201410553325A CN 104297706 B CN104297706 B CN 104297706B
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Abstract
The invention discloses a kind of field generator for magnetic based on resonance and its method for designing, compared to common field generator for magnetic, its main innovation is the conversion efficiency that electricity greatly improved to magnetic, realizes low noise, the generation in low harmony wave magnetic field.It is determined that after electromagnetic field generating coil and inspection leakage resistance specification, calculating their series impedance Z under working frequency fL；Using series impedance ZLCalculate that resonance current compares IratioMaximum；I is compared according to desired resonance currentratio, filter cutoff frequency f1、f2, passband ripple derivation filter parameter；Finally to field generator for magnetic assembly and adjustment.
Description
Technical field
The invention belongs to magnetic field generation technique field, more particularly, to a kind of field generator for magnetic based on resonance, more
Specifically, it is related to a kind of efficient field generator for magnetic based on resonance principle, for producing high s/n ratio single-frequency magnetic field.
Background technology
Magnetic phenomenon is earliest that by one of physical phenomenon of human cognitive, the compass of one of ancient Chinese four inventions is exactly
The magnetic field force induced effect in earth's magnetic field using needle, so as to be taken one's bearings.In modern age, a series of revolutionary discovery is caused
It was recognized that close between electricity and magnetic contact, and the mutual conversion between electricity and magnetic is realized using the rule grasped.
Application of the magnetic field in production and scientific experiment is more and more extensive, for example, in the magnetism characteristic measurement of magnetic material,
It is accomplished by producing a certain size magnetic field as the magnetizing field of material.In particular for the physics of these magnetic materials of accurate measurement
During characteristic, magnetizing field should have stabilization, low noise, without harmonic wave the characteristics of.
Conventional AC magnetic field generation device performance depends primarily on the power amplifier properties inside device at present.Work as reality
Testing has more high request to magnetizing field, and the performance requirement of power amplifier is harsher, and even harshness is difficult to reality to prior art sometimes
It is existing.In order to reduce dependence of the device performance to power amplifier, it is necessary to design a kind of new field generator for magnetic.
The content of the invention
For the disadvantages described above or Improvement requirement of prior art, filled the invention provides a kind of magnetic field based on resonance
Put with its method for designing.Its object is to greatly improve electricity to the conversion efficiency of magnetic, low noise, low harmony wave magnetic field are thus solved
Generation problem.
According to one aspect of the present invention, there is provided a kind of field generator for magnetic based on resonance, described device includes work
Control machine, data collecting card, power amplifier, wave filter, and electromagnetic field generating coil and inspection leakage resistance, wherein：
Two-way communication between the industrial computer and data collecting card, industrial computer passes through data collecting card output drive waveform number
According to simultaneous data-collecting card also occurs coil current information to industrial computer feedback magnetic field；
The output port of data collecting card is connected to power amplifier, and excitation waveform after power amplification by successively acting on
On wave filter, electromagnetic field generating coil, inspection leakage resistance；
Data collecting card obtains electromagnetic field generating coil current information by gathering inspection leakage resistance voltage.
Further, the wave filter includes resistance R1, series capacitance C1, series inductance L1It is serially connected, shunt capacitance
C2, shunt inductance L2It is parallel with one another, wherein：
Resistance R1, series capacitance C1With series inductance L1It is serially connected；
Shunt capacitance C2With shunt inductance L2It is parallel with one another；
The resistance R of series connection1, series capacitance C1With series inductance L1, then with shunt capacitance C in parallel2With shunt inductance L2String
Connection.
It is another aspect of this invention to provide that additionally providing a kind of design side of the above-mentioned field generator for magnetic based on resonance
Method, comprises the following steps：
(1) there is the series impedance Z of electromagnetic field generating coil and inspection leakage resistance under working frequency f in calculating magnetic fieldL, wherein ZL
=p+qj, remembers Z2It is shunt inductance L2With shunt capacitance C2Parallel impedance under working frequency f, is expressed as Z2=aj；
(2) drafting functionCurve, finds the corresponding coordinate [a of curve maximumopt, Imax]；
(3) by the low cut-off frequency f of wave filter2With parameter aoptBring equation group intoSolve in parallel
Inductance L2, shunt capacitance C2；
(4) by wave filter higher cutoff frequency f1With parameter yoptBring equation group intoSolve series connection
Inductance L1, series capacitance C1, wherein yoptIt is the optimal value of y, y is Z1Imaginary part, yopt=-1 × imag (Z2||Z3), Z1It is electricity
Resistance R1, series capacitance C1, series inductance L1Series impedance；
(5) emulation is in different resistance R1Under value condition, the amplitude versus frequency characte of wave filter selects suitable R1To meet passband
The requirement of ripple.
In general, by the contemplated above technical scheme of the present invention compared with prior art, with following beneficial effect
Really：
(1) field generator for magnetic is designed based on resonance principle, and the reactive power that need to be provided by power amplifier originally is transferred
Voluntarily provided by the passive element in wave filter, produced under identical magnetic field, the apparent energy of power amplifier is greatly reduced, from
And electricity to the conversion efficiency of magnetic greatly improved；
(2) wave filter in field generator for magnetic has filter function in itself, therefore there is low harmony wave to lose in the magnetic field for producing
Very, the characteristics of low noise；
(3) by real-time detection electromagnetic field generating coil electric current, realizing the closed-loop control of electric current can become component ageing, temperature
Change the influence to magnetic field to be greatly reduced, improve the stability in magnetic field.
Brief description of the drawings
Fig. 1 is a kind of conventional field generator for magnetic structural representation；
Fig. 2 is field generator for magnetic structural representation of the invention；
Fig. 3 is the circuit diagram of field generator for magnetic of the present invention；
Fig. 4 is the simplification to the circuit diagram shown in Fig. 3；
Fig. 5 is the flow chart of field generator for magnetic method for designing of the present invention；
Fig. 6 is resonance current than the function curve that changes with parameter a；
Fig. 7 is the circuit diagram of complete design device in the embodiment of the present invention；
Fig. 8 is the curve of output in the embodiment of the present invention using common field generator for magnetic power amplifier；
Fig. 9 is the curve of output in the embodiment of the present invention using method for designing power amplifier of the invention；
Figure 10 is magnetic field size time history plot in the embodiment of the present invention.
Specific embodiment
In order to make the purpose , technical scheme and advantage of the present invention be clearer, it is right below in conjunction with drawings and Examples
The present invention is further elaborated.It should be appreciated that the specific embodiments described herein are merely illustrative of the present invention, and
It is not used in the restriction present invention.As long as additionally, technical characteristic involved in invention described below each implementation method
Not constituting conflict each other can just be mutually combined.
As shown in figure 1, being a kind of structural representation of conventional field generator for magnetic.Handed over by electromagnetic field generating coil is logical
Time-dependent current is the most popular method for producing alternating magnetic field, in Fig. 1 the output of industrial computer control data capture card output drive waveform,
Alternating magnetic field is produced by act directly on be used on electromagnetic field generating coil after power amplifier.
As shown in Fig. 2 being field generator for magnetic structural representation of the invention, the field generator for magnetic includes industry control
Machine, data collecting card, power amplifier, wave filter, electromagnetic field generating coil and inspection leakage resistance.Between industrial computer and data collecting card
Two-way communication, by data collecting card output drive Wave data, simultaneous data-collecting card also feeds back magnetic to industrial computer to industrial computer
There is coil current information in field.The output port of data collecting card is connected to power amplifier, and excitation waveform passes through power amplification
Successively act on afterwards on wave filter, electromagnetic field generating coil, inspection leakage resistance.Data collecting card is obtained by gathering inspection leakage resistance voltage
Electromagnetic field generating coil current information is taken, industrial computer is sent out magnetic field by electromagnetic field generating coil current setting value with the error of value of feedback
Raw coil current carries out proportional plus integral control so that electromagnetic field generating coil electric current stabilization.
As shown in figure 3, the circuit diagram of the field generator for magnetic include AC power supplies, wave filter (shown in dotted line frame) with
And load impedance ZL.AC power supplies represents power amplifier, and dotted line frame represents the structure of wave filter, load impedance ZLRepresent line
Circle and inspection leakage resistance series impedance at the operating frequencies under f.The structure of wave filter is similar with second order bandpass filtering, resistance
R1, series capacitance C1, series inductance L1It is serially connected, shunt capacitance C2, shunt inductance L2It is parallel with one another.
As shown in figure 4, being the simplification to circuit diagram shown in Fig. 3.Wherein Z1Represent R in Fig. 31、C1、L1Series connection resistance
It is anti-, Z2Represent C in Fig. 32、L2Parallel impedance, ZLRepresent electromagnetic field generating coil and inspection leakage resistance f at the operating frequencies
Series impedance.I1Expression flows through Z1Branch current, I2Expression flows through Z2Branch current, ILRepresent load branch electric current.
In the field generator for magnetic simplification figure shown in Fig. 4, load current ILWith power amplifier output current I1The ratio between modulus value be
Electric current ratioIt is designated as IratioMeet formula (1)：
Be apparent from this ratio only with Z2, ZLIt is relevant, understand from the angle of circuit theory, now Z2With ZLConstitute parallel resonance,
When the characteristics of current resonance is that circuit is in resonance, the electric current on resonant branch is more than input current, and the present invention is based on this
A bit, make shunt inductance and electric capacity in electromagnetic field generating coil and inspection leakage resistance and wave filter that resonance occurs, to cause that magnetic field is sent out
Electric current on raw coil and inspection leakage resistance is less than power amplifier output current, so that raising efficiency.Wherein, ZLIt is that magnetic field occurs
Series impedance of the coil with inspection leakage resistance under working frequency f, after electromagnetic field generating coil determines with inspection leakage resistance, ZLIt is worth for normal
Amount, can represent ZL=p+qj；Z2It is shunt inductance L2With shunt capacitance C2Parallel impedance under working frequency f, is represented by Z2
=aj, by ZL、Z2Bring into and formula (2) is obtained in formula (1)：
Electric current ratio is IratioThe function of parameter a, by the curve of function shown in the formula of drawing (2), finds curve maximum pair
Coordinate [a for answeringopt, Imax]。
The low cut-off frequency f of wave filter2With Z2Relation can be represented by equation group (3)：
Equation group (3) brings Z into2=aoptJ, and equation group (4) can obtain with solution deformation to it：
Equation group (4) has more directly reacted the low cut-off frequency f of wave filter2With shunt inductance L2, shunt capacitance C2Pass
System.
C2, L2Selection principle be to make load impedance (the i.e. Z of power amplifier1+Z2||ZL) minimum.Z2, ZLParallel value Z2||
ZLIt is represented by formula (5)：
Z1Imaginary part and Z2||ZLImaginary part and value be zero be Z1+Z2||ZLTake the necessary condition of minimum value.From circuit theory
From the perspective of, now there is series resonance in circuit, be characterized in circuit loop in resistive, and whole impedance loop is minimum, electricity
Stream I1Reach maximum.If Z1Imaginary part is y, as y and Z2||ZLWhen imaginary values and value are zero there is series resonance in circuit, and the optimal of y takes
Value yoptCan be represented with formula (6)：
yopt=-1 × imag (Z2||ZL) (6)
Wherein imag is represented and is taken imaginary part function, yoptRepresent Z1Imaginary part is the optimal value of y.
Wave filter higher cutoff frequency f1With Z1The relation of imaginary part y can be represented by equation group (7)：
Equation group (5) brings y=y intoopt, and equation group (8) can obtain with solution deformation to it：
Equation group (8) has more directly reacted wave filter higher cutoff frequency f1With series inductance L1, series capacitance C1Pass
System.
Resistance R1Ripple of the main influence wave filter in passband, when selected value is too small, ripple rises and falls greatly in passband, is elected to
Value is excessive, it will the big energy of consumption, reduces operating efficiency.Suitable R1Value causes passband ripple small and energy ezpenditure
It is few.
As shown in figure 5, the invention provides a kind of method for designing of the field generator for magnetic based on resonance, including following step
Suddenly：
(1) there is the series impedance Z of electromagnetic field generating coil and inspection leakage resistance under working frequency f in calculating magnetic fieldL。
In a concrete instance, working frequency f=1kHz, electromagnetic field generating coil DC impedance is 0.18 Ω, inductance value
0.35mH, inspection leakage resistance size is 0.125 Ω, can calculate ZL=0.305+2.199j.
(2) drafting functionCurve, finds the corresponding coordinate of curve maximum
[aopt, Imax]。
Wherein, p=0.305, q=2.199, the function curve of drafting is as shown in fig. 6, the corresponding coordinate of curve maximum is
[- 2.243,7.26].Therefore, aopt=-2.24, Imax=7.28.
(3) by the low cut-off frequency f of filter characteristic2With parameter aoptBring equation group intoSolve
Shunt inductance L2, shunt capacitance C2。
Take f2=650Hz, aopt=-2.243 bring equation group into, solve L2=485uH, C2=124uF.
(4) wave filter higher cutoff frequency f1With parameter yoptBring equation group intoSolve series electrical
Sense L1, series capacitance C1。
Z2||ZLImaginary part be 0.09, therefore take yopt=-0.09, f1=1350Hz brings equation group into, solves L1=
17.3uH, C1=803uF.
(5) under the filter parameter that (1)~(4) step is given more than, emulate in different R1Under value condition, wave filter
Amplitude versus frequency characte.Simulation result shows, works as R1During=0.6 Ω, filter passband ripple is less than 0.3dB, and wave filter has preferably logical
Band flatness.
(6) assembling of field generator for magnetic and debugging：What (1)~(5) step was given above is the theoretical ginseng of wave filter design
Count, the parameter of element has certain specification to limit in practice, such as series inductance C1It is 803uF to be worth, in practice this great Rong
The electric capacity of value is difficult to buy, it is therefore desirable to which component parameters are optimized.Device circuit schematic diagram after component parameters optimization is such as
Shown in Fig. 7.Finally to device assembly and adjustment.
Actual test data analysis：
1. in concrete instance, electromagnetic field generating coil parameter is that electromagnetic field generating coil can often be produced by 1A electric currents for 10Gs/A
Raw 10Gs magnetic fields.Produce 30Gs magnetic fields using two kinds of devices shown in Fig. 1, Fig. 2 respectively, the output parameter of recording power amplifier with
And magnetic field size, as shown in Figure 8,9, 10.
Fig. 8 is curve of output of the power amplifier in a cycle when using Fig. 1 shown devices to produce 30Gs magnetic fields.
Power amplifier output current amplitude 3A, voltage magnitude 6.1V, can calculate apparent energy 12.9W.
Fig. 9 is curve of output of the power amplifier in a cycle when using Fig. 2 shown devices to produce 30Gs magnetic fields.
Power amplifier output current amplitude 0.46A, voltage magnitude 7.2V, can calculate apparent energy 2.34W.
Figure 10 is situation of change of the magnetic field in 500s produced by two kinds of devices shown in Fig. 1, Fig. 2, it is clear that the present invention is set
More stablize in the magnetic field that counter device is produced.
As it will be easily appreciated by one skilled in the art that the foregoing is only presently preferred embodiments of the present invention, it is not used to
The limitation present invention, all any modification, equivalent and improvement made within the spirit and principles in the present invention etc., all should include
Within protection scope of the present invention.
Claims (2)
1. a kind of field generator for magnetic based on resonance, it is characterised in that described device includes industrial computer, data collecting card, work(
Rate amplifier, wave filter, and electromagnetic field generating coil and inspection leakage resistance, wherein：
Two-way communication between the industrial computer and data collecting card, industrial computer passes through data collecting card output drive Wave data,
Also there is coil current information to industrial computer feedback magnetic field in simultaneous data-collecting card；
The output port of data collecting card is connected to power amplifier, and excitation waveform after power amplification by successively acting on filter
On ripple device, electromagnetic field generating coil, inspection leakage resistance；
The wave filter includes resistance R1, series capacitance C1, series inductance L1It is serially connected, shunt capacitance C2, shunt inductance L2Phase
It is mutually in parallel, wherein：Resistance R1, series capacitance C1With series inductance L1It is serially connected；Shunt capacitance C2With shunt inductance L2Mutually simultaneously
Connection；The resistance R of series connection1, series capacitance C1With series inductance L1, then with shunt capacitance C in parallel2With shunt inductance L2Series connection；
Data collecting card obtains electromagnetic field generating coil current information by gathering inspection leakage resistance voltage, and industrial computer occurs by magnetic field
Coil current setting value carries out proportional plus integral control with the error of value of feedback to electromagnetic field generating coil electric current so that magnetic field occurs line
Loop current stabilization；The field generator for magnetic is designed based on resonance principle, and this reactive power that need to be provided by power amplifier turns
And voluntarily provided by the passive element in wave filter, producing under identical magnetic field, the apparent energy of power amplifier is reduced, so that
Improve electricity to the conversion efficiency of magnetic.
2. a kind of method for designing of field generator for magnetic as claimed in claim 1, it is characterised in that methods described includes as follows
Step：
(1) there is the series impedance Z of coil and inspection leakage resistance under working frequency f in calculating magnetic fieldL, wherein ZL=p+qj, remembers Z2For
Shunt inductance L2With shunt capacitance C2Parallel impedance under working frequency f, is expressed as Z2=aj；
(2) drafting functionCurve, finds the corresponding coordinate [a of curve maximumopt, Imax]；
(3) by the low cut-off frequency f of wave filter2With parameter aoptBring equation group intoSolve shunt inductance
L2, shunt capacitance C2；
(4) by wave filter higher cutoff frequency f1With parameter yoptBring equation group intoSolve series inductance
L1, series capacitance C1, wherein yoptIt is the optimal value of y, y is Z1Imaginary part, yopt=-1 × imag (Z2||ZL), Z1It is resistance
R1, series capacitance C1, series inductance L1Series impedance；
(5) emulation is in different resistance R1Under value condition, the amplitude versus frequency characte of wave filter selects suitable R1To meet passband ripple
Requirement.
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| CN108735421A (en) * | 2018-06-07 | 2018-11-02 | 东北电力大学 | A kind of alternating electromagnetic field generating means based on parallel resonance principle |
| WO2020065651A1 (en) * | 2018-09-27 | 2020-04-02 | Peled Yona | Method and apparatus for multi-channel simultaneously high power magnetic coil driver |
| CN117616663A (en) * | 2022-06-20 | 2024-02-27 | 北京小米移动软件有限公司 | Wireless receiving circuit, configuration method thereof, electronic device and readable storage medium |
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