CN105262331A - High current DC filter - Google Patents
High current DC filter Download PDFInfo
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- CN105262331A CN105262331A CN201510844536.6A CN201510844536A CN105262331A CN 105262331 A CN105262331 A CN 105262331A CN 201510844536 A CN201510844536 A CN 201510844536A CN 105262331 A CN105262331 A CN 105262331A
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- iron core
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Abstract
The embodiment of the invention discloses a high current DC filter, which comprises a first iron core and a second iron core arranged on a primary winding in a sleeving mode, wherein the first iron core is provided with a gap, the gap is internally provided with a Hall sensor, the output end of the Hall sensor is sequentially serially connected with a low pass filter circuit, a preamplifier circuit, a servo current source, a second secondary winding arranged on the second iron core and a first secondary winding arranged on the first iron core, and the other end of the first secondary winding is grounded. According to the high current DC filter provided by the embodiment of the invention, the first secondary winding arranged on the first iron core and the second secondary winding arranged on the second iron core and the primary winding generate magnetic fields with the same size and opposite direction, DC zero flux is formed inside the first iron core and the second iron core, a large inductance value is generated as the second iron core has no gap, and high restraint effects are played on DC high current ripples.
Description
Technical field
The present invention relates to wave filter technology field, particularly relate to a kind of heavy DC filter.
Background technology
Along with develop rapidly and the extensive use of the DC load such as electric automobile, direct current energy metering becomes an important component part of electric-power metering, in order to examine and determine various direct current energy meter, needs to develop the high adjustable accurate D.C. high-current source of stability.At present, D.C. high-current source adopts Switching Power Supply to realize usually, and the output ripple of Switching Power Supply is determined by the energy storage inductor of Switching Power Supply and storage capacitor.Common Switching Power Supply is large due to ripple current, can reduce the stability that D.C. high-current source exports, and makes it the requirement that can not meet calibrating direct current energy meter.
Due to inductance, to have DC impedance low, and the characteristic that AC impedance is large, utilizes large inductance to be a kind of very effective mode to suppress the ripple of heavy DC current source.LC filter is the basic skills reducing ripple and noise, the Voltage Peak peak value V obtained after single-stage LC filter filtering
r (pp)shown in one:
Formula one:
Wherein, V
r (pp)for LC filter output voltage peak-to-peak value, V
in (pp)for Voltage Peak peak value before filtering, L is the inductance value of LC filter, and C is the capacitance of LC filter.
As can be seen from formula one, for the ripple of certain frequency, through LC filtering, the rejection ratio of input ripple is determined by the product of inductance and electric capacity, and inductance is larger, and electric capacity is larger, stronger to the inhibitory action of ripple.
In order to increase inductance, usually in the design of inductor, introducing iron core, introducing the inductance value of the inductor of iron core such as formula shown in two:
Formula two:
Wherein, MPL is iron circuit length, μ
mfor iron core maximum permeability, N is the number of turn of coil, A
cfor core section amasss.
In addition, in order to avoid iron core magnetic is saturated and must introduce air gap in the core which, introduce the inductance value of the inductor after air gap such as formula shown in three:
Formula three:
Wherein l
gfor air-gap magnetic circuit length.
From formula two and formula three, after iron core opens air gap, the inductance value of inductor reduces, and namely introduces air gap in the core which, limits the increase of inductance value.
In addition, jumbo electric capacity is bulky, and its by ripple current be limited, strengthen also not easily realizing the rejection of ripple by the capacitance improving LC filter.
In sum, existing LC filter cannot meet heavy DC filtering requirements, therefore, a kind ofly urgently to occur the heavy DC filter that ripple has a better inhibition.
Summary of the invention
Provide a kind of heavy DC filter in the embodiment of the present invention, the problem of heavy DC filtering requirements cannot be met to solve LC filter in prior art.
In order to solve the problems of the technologies described above, the embodiment of the invention discloses following technical scheme:
A kind of heavy DC filter, comprise for being set in the first iron core on armature winding and the second iron core, described first iron core is provided with air gap, Hall element is provided with in described air gap, the output of described Hall element is in series with low-pass filter circuit, pre-amplification circuit, servo current source, the first secondary winding of being around in the second subprime winding on the second iron core and being around on the first iron core successively, the other end ground connection of described second subprime winding;
The number of turn of described armature winding is n
1, the number of turn of described first secondary winding and second subprime winding is n
2, when the current value in armature winding is I
ptime, the current value in the first secondary winding and second subprime winding is I
2, and meet relation: n
1i
p=n
2i
2.
Preferably, described Hall element comprises the first amplifier, the second amplifier and hall device, described first amplifier is used for providing constant operating current to hall device, described second amplifier is for offsetting the in-phase voltage of hall device, and it take earth potential as the Hall voltage of benchmark that described hall device is used for the output when magnetic flux being detected.
Preferably, the input of described low-pass filter circuit connects the output of described Hall element, for suppressing the high-frequency voltage signal in Hall voltage.
Preferably, the input of described pre-amplification circuit connects the output of described low-pass filter circuit, for being amplified by the voltage linear of input.
Preferably, described pre-amplification circuit is 10-100 times to the multiplication factor of voltage.
Preferably, the multiplication factor of described enlarge leadingly current vs voltage is 10 times.
Preferably, described servo current source comprises the 3rd amplifier and the 4th amplifier, the input of described 3rd amplifier connects the output of pre-amplification circuit, the output of described 4th amplifier connects the first secondary winding, and described servo current source is used for exporting corresponding electric current according to the voltage of input.
Preferably, the length of described air gap is 1.5mm.
Preferably, the number of turn n of described first secondary winding and second subprime winding
2=2500.
Preferably, described first iron core is the ferrite iron core that high frequency performance is good, and described second iron core is the amorphous iron core that initial magnetic permeability is high.
From above technical scheme, a kind of heavy DC filter that the embodiment of the present invention provides produces with the second subprime winding be around on the second iron core and first winding the magnetic field that size is identical, direction is contrary by the first secondary winding be around on the first iron core, make to form direct current Zero flux in the first iron core and the second iron core, and the second iron core is not opened air gap and can be produced larger inductance value, has higher inhibition to D.C. high-current ripple.
Accompanying drawing explanation
In order to be illustrated more clearly in the embodiment of the present invention or technical scheme of the prior art, be briefly described to the accompanying drawing used required in embodiment or description of the prior art below, apparently, for those of ordinary skills, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to these accompanying drawings.
A kind of heavy DC filter construction schematic diagram that Fig. 1 provides for the embodiment of the present invention;
The Hall element circuit diagram that Fig. 2 provides for the embodiment of the present invention;
The servo current source circuit figure that Fig. 3 provides for the embodiment of the present invention;
Symbol in Fig. 1-Fig. 3 is expressed as: 1-Hall element, 2-pre-amplification circuit, 3-servo current source, 4-hall device, TA-first iron core, TB-second iron core, N
1-armature winding, N
2-second subprime winding, N
3-the first secondary winding, A
1-the first amplifier, A
2-the second amplifier, A
3-three amplifier, A
4-four amplifier.
Embodiment
Technical scheme in the present invention is understood better in order to make those skilled in the art person, below in conjunction with the accompanying drawing in the embodiment of the present invention, technical scheme in the embodiment of the present invention is clearly and completely described, obviously, described embodiment is only the present invention's part embodiment, instead of whole embodiments.Based on the embodiment in the present invention, those of ordinary skill in the art, not making the every other embodiment obtained under creative work prerequisite, should belong to the scope of protection of the invention.
A kind of heavy DC filter construction schematic diagram that Fig. 1 provides for the embodiment of the present invention, as shown in Figure 1, a kind of heavy DC filter that the embodiment of the present invention provides, comprises for being set in armature winding N
1on the first iron core TA and the second iron core TB, first iron core TA is provided with air gap, be provided with Hall element 1 in air gap, the output of Hall element 1 is in series with low-pass filter circuit, pre-amplification circuit 2, servo current source 3, the second subprime winding N be around on the second iron core TB successively
2and the first secondary winding N be around on the first iron core TA
3, the first secondary winding N
3other end ground connection.Armature winding N
1the number of turn be n
1, be generally 1 circle, the first secondary winding N
3with second subprime winding N
2the number of turn be n
2, n in an advantageous embodiment
2select 2500 circles.
As armature winding N
1in have direct current I
pby time, direct current I
pmagnetic field is produced in the first iron core TA and the second iron core TB, magnetic flux now in the first iron core TA is non-vanishing, Hall element 1 exports Hall voltage, this Hall voltage is after low-pass filter circuit filtering and pre-amplification circuit 2 are amplified, control servo current source 3 and produce output current, the size of this output current is I
2, electric current I
2flow through the first secondary winding N successively
3with second subprime winding N
2, at the first secondary winding N
3with second subprime winding N
2the rightabout magnetic field of middle generation, works as n
1i
p=n
2i
2time, electric current I
pwith electric current I
2produce the magnetic field that size is identical, direction is contrary, two magnetic fields offset, and namely realize direct current Zero flux.
Usually D.C. magnetic field magnetic flux density and AC magnetic field magnetic flux density is comprised in iron core of the prior art, and the heavy DC filter that the embodiment of the present invention provides can realize direct current Zero flux in iron core, namely only comprise AC magnetic field magnetic flux density in iron core in embodiments of the present invention, solve the easy magnetically saturated problem of inductor in prior art.For the first iron core TA, inductance value is determined by formula three, and due to the existence of air gap, its inductance value is very little; And for the second iron core TB, inductance value is determined by formula two, due to the material core material that permeability can be selected very high, the inductance value of this second iron core TB is comparatively large, thus has stronger inhibitory action to ripple current, and not easily produces magnetic saturation.
The Hall element circuit diagram that Fig. 2 provides for the embodiment of the present invention, as shown in Figure 2, Hall element 1 is made up of the first amplifier A1, the second amplifier A2, hall device 4 and a series of resistance, Hall element 1 needs the external world to provide current source when working, and namely provides Hall element 1 input voltage V
rEF, when being placed in magnetic field, hall device 4 can produce induced voltage perpendicular to magnetic direction and the sense of current, i.e. Hall voltage V
h.
In fig. 2, first amplifier A1 is used for providing constant operating current to hall device 4, second amplifier A2 is for offsetting the in-phase voltage of hall device 4, due to the in-phase end earthing potential of the second amplifier A2, therefore, when the second amplifier A2 normally works, its end of oppisite phase also should be earth potential.That is, the output of hall device 4 obtains taking earth potential as the Hall voltage V of benchmark
h, this makes follow-up amplification process not need to use differential amplifier, and the internal resistance of hall device 4 also can not affect the gain of amplifier.Wherein, V
rEFfor input voltage, the I of Hall element 1
hfor the operating current of hall device 4, V
hfor taking earth potential as the Hall voltage of benchmark.
The servo current source circuit figure that Fig. 3 provides for the embodiment of the present invention, as shown in Figure 3, servo current source 3 comprises the 3rd amplifier A3 and the 4th amplifier A4, the input of described 3rd amplifier A3 connects the output of pre-amplification circuit 2, and the output of described 4th amplifier A4 connects second subprime winding N
2, described servo current source 3 exports corresponding electric current for the voltage according to input, and namely the electric current that this servo current source 3 exports flows through the first secondary winding N
3with second subprime winding N
2electric current.
3rd amplifier A3 forms integrator structure, is equivalent to the infinitely-great voltage amplifier of gain, and the 4th amplifier A4 forms voltage amplifier, and its output is connected to the first secondary winding N
3.
When system offset from zero magnetic flux state, produce faint Hall voltage, the input of low-pass filter circuit connects the output of Hall element 1, and Hall voltage, through low-pass filter circuit filtering, exports after suppressing the high-frequency voltage signal in Hall voltage; The input of pre-amplification circuit 2 connects the output of low-pass filter circuit, export pre-amplification circuit 2 through the filtered voltage of low-pass filter circuit to amplify, under normal circumstances, the multiplication factor of pre-amplification circuit 2 pairs of voltages is 10-100 times, be preferably 10 times in the present embodiment, but those skilled in the art can correspondingly according to actual needs adjust, and should not it can be used as the restriction of scope; The output of pre-amplification circuit 2 connects the input in servo current source 3, and through the voltage input servo current source 3 that pre-amplification circuit 2 amplifies, servo current source 3 exports corresponding electric current according to the voltage of input, and this electric current flows through second subprime winding N successively
2with the first secondary winding N
3, at the first secondary winding N
3with second subprime winding N
2the rightabout magnetic field of middle generation, works as n
1i
p=n
2i
2time, electric current I
pwith electric current I
2produce the magnetic field that size is identical, direction is contrary, two magnetic fields offset, and namely realize the direct current Zero flux of the first iron core TA and the second iron core TB.That is, Hall element 1 serves the effect of an instruction Zero flux, and the time that system balancing is set up is no more than 1 μ s.
In an advantageous embodiment, in the first iron core TA, the length of air gap is 1.5mm, and the first iron core TA selects the ferrite iron core that high frequency performance is good, and the second iron core TB selects the amorphous iron core that initial magnetic permeability is high.
When opening air gap in iron core, due to air-gap magnetic circuit length l
gwill much larger than iron circuit length MPL and iron core maximum permeability μ
mratio, therefore, formula four can be reduced to for introducing the iron inductance value of air gap:
Formula four:
wherein, N is coil turn, A
cfor core section amasss, l
gfor air-gap magnetic circuit length.
From formula four, with the iron inductance value of air gap by coil turn, core section sum air-gap magnetic circuit length determines, and iron core maximum permeability it doesn't matter, therefore, more difficult to do large inductance for the iron core having air gap.That is, the first iron core TA inductance value in the embodiment of the present invention is lower, but the second iron core TB in the embodiment of the present invention is not owing to opening air gap, its inductance value can represent by above-mentioned formula two, second iron core TB selects the amorphous iron core that initial magnetic permeability is high, iron core maximum permeability is higher, therefore very large inductance value can be obtained, to heavy DC ripple, there is good inhibition, and owing to realizing direct current Zero flux in the first iron core TA after system stability and the second iron core TB, therefore, magnetically saturated problem in the first iron core TA and the second iron core TB need not be worried.
From above technical scheme, a kind of heavy DC filter that the embodiment of the present invention provides is by being around in the first secondary winding N on the first iron core TA
3with the second subprime winding N be around on the second iron core TB
2with first winding N
1produce that size is identical, magnetic field that direction is contrary, make to form direct current Zero flux in the first iron core TA and the second iron core TB, and the second iron core TB does not open air gap can produce larger inductance value, to D.C. high-current ripple, there is higher inhibition.
It should be noted that, in this article, the such as relational terms of " first " and " second " etc. and so on is only used for an entity or operation to separate with another entity or operating space, and not necessarily requires or imply the relation that there is any this reality between these entities or operation or sequentially.And, term " comprises ", " comprising " or its any other variant are intended to contain comprising of nonexcludability, thus make to comprise the process of a series of key element, method, article or equipment and not only comprise those key elements, but also comprise other key elements clearly do not listed, or also comprise by the intrinsic key element of this process, method, article or equipment.When not more restrictions, the key element limited by statement " comprising ... ", and be not precluded within process, method, article or the equipment comprising described key element and also there is other identical element.
The above is only the specific embodiment of the present invention, those skilled in the art is understood or realizes the present invention.To be apparent to one skilled in the art to the multiple amendment of these embodiments, General Principle as defined herein can without departing from the spirit or scope of the present invention, realize in other embodiments.Therefore, the present invention can not be restricted to these embodiments shown in this article, but will meet the widest scope consistent with principle disclosed herein and features of novelty.
Claims (10)
1. a heavy DC filter, is characterized in that, comprises for being set in armature winding (N
1) on the first iron core (TA) and the second iron core (TB), described first iron core (TA) is provided with air gap, be provided with Hall element (1) in described air gap, the output of described Hall element (1) is in series with low-pass filter circuit, pre-amplification circuit (2), servo current source (3), the second subprime winding (N be around on the second iron core (TB) successively
2) and the first secondary winding (N of being around on the first iron core (TA)
3), described first secondary winding (N
3) other end ground connection;
Described armature winding (N
1) the number of turn be n
1, described first secondary winding (N
3) and second subprime winding (N
2) the number of turn be n
2, as armature winding (N
1) in current value be I
ptime, the first secondary winding (N
3) and second subprime winding (N
2) in current value be I
2, and meet relation: n
1i
p=n
2i
2.
2. heavy DC filter according to claim 1, is characterized in that, described Hall element (1) comprises the first amplifier (A
1), the second amplifier (A
2) and hall device (4), described first amplifier (A
1) for providing constant operating current to hall device (4), described second amplifier (A
2) for offsetting the in-phase voltage of hall device (4), described hall device (4) is the Hall voltage of benchmark with earth potential for the output when magnetic flux being detected.
3. heavy DC filter according to claim 2, is characterized in that, the input of described low-pass filter circuit connects the output of described Hall element (1), for suppressing the high-frequency voltage signal in Hall voltage.
4. heavy DC filter according to claim 3, is characterized in that, the input of described pre-amplification circuit (2) connects the output of described low-pass filter circuit, for being amplified by the voltage linear of input.
5. heavy DC filter according to claim 4, is characterized in that, described pre-amplification circuit (2) is 10-100 times to the multiplication factor of voltage.
6. heavy DC filter according to claim 5, is characterized in that, described pre-amplification circuit (2) is 10 times to the multiplication factor of voltage.
7. heavy DC filter according to claim 4, is characterized in that, described servo current source (3) comprises the 3rd amplifier (A
3) and the 4th amplifier (A
4), described 3rd amplifier (A
3) input connect pre-amplification circuit (2) output, described 4th amplifier (A
4) output connect the first secondary winding (N
3), described servo current source (3) exports corresponding electric current for the voltage according to input.
8. heavy DC filter according to claim 1, its spy is, the length of described air gap is 1.5mm.
9. heavy DC filter according to claim 1, its spy is, described first secondary winding (N
3) and second subprime winding (N
2) number of turn n
2=2500.
10. heavy DC filter according to claim 1, its spy is, described first iron core (TA) is the good ferrite iron core of high frequency performance, and described second iron core (TB) is the high amorphous iron core of initial magnetic permeability.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510844536.6A CN105262331B (en) | 2015-11-27 | 2015-11-27 | A kind of heavy DC wave filter |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510844536.6A CN105262331B (en) | 2015-11-27 | 2015-11-27 | A kind of heavy DC wave filter |
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| Publication Number | Publication Date |
|---|---|
| CN105262331A true CN105262331A (en) | 2016-01-20 |
| CN105262331B CN105262331B (en) | 2017-10-13 |
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ID=55101878
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|---|---|---|---|
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105785095A (en) * | 2016-04-21 | 2016-07-20 | 中车青岛四方机车车辆股份有限公司 | Constant-amplitude DC pulse signal measurement circuit and degaussing method thereof |
| CN108988670A (en) * | 2017-05-31 | 2018-12-11 | 本田技研工业株式会社 | Electric device and its manufacturing method |
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| US3395327A (en) * | 1966-08-31 | 1968-07-30 | Westinghouse Electric Corp | High voltage direct current transmission system with condition responsive, tunable, harmonic filters |
| US4651266A (en) * | 1984-02-16 | 1987-03-17 | Fanuc Ltd | High-frequency noise absorbing circuit |
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| CN105785095A (en) * | 2016-04-21 | 2016-07-20 | 中车青岛四方机车车辆股份有限公司 | Constant-amplitude DC pulse signal measurement circuit and degaussing method thereof |
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| CN108988670B (en) * | 2017-05-31 | 2020-08-18 | 本田技研工业株式会社 | Power device and method for manufacturing the same |
Also Published As
| Publication number | Publication date |
|---|---|
| CN105262331B (en) | 2017-10-13 |
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