CN203572875U - Current detection device for large direct current charge-discharge facility - Google Patents
Current detection device for large direct current charge-discharge facility Download PDFInfo
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- CN203572875U CN203572875U CN201320695949.9U CN201320695949U CN203572875U CN 203572875 U CN203572875 U CN 203572875U CN 201320695949 U CN201320695949 U CN 201320695949U CN 203572875 U CN203572875 U CN 203572875U
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- 238000001514 detection method Methods 0.000 title claims abstract description 37
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 29
- 238000005070 sampling Methods 0.000 claims abstract description 20
- 238000004804 winding Methods 0.000 claims abstract description 17
- 238000012545 processing Methods 0.000 claims abstract description 9
- 230000003321 amplification Effects 0.000 claims description 9
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 9
- 230000003534 oscillatory effect Effects 0.000 claims description 7
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- 239000003990 capacitor Substances 0.000 claims description 3
- 238000012360 testing method Methods 0.000 abstract description 5
- 238000005259 measurement Methods 0.000 description 7
- 238000000034 method Methods 0.000 description 7
- 230000008569 process Effects 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 4
- 238000005086 pumping Methods 0.000 description 4
- 230000005540 biological transmission Effects 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000007599 discharging Methods 0.000 description 2
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- 238000013500 data storage Methods 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 239000011888 foil Substances 0.000 description 1
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- 238000009413 insulation Methods 0.000 description 1
- 238000013507 mapping Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
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Abstract
The utility model relates to the technical field of large direct current detection, in particular to a current detection device for a large direct current charge-discharge facility. According to the technical scheme, the current detection device comprises a comparator, the comparator comprises two modulation detection iron cores, the peripheries of the two modulation detection iron cores are wound by detection windings, the two modulation detection iron cores are arranged in an overlapped mode and connected in a series-opposing mode, the peripheries of the two modulation detection iron cores are wound by a secondary winding and a primary winding in sequence, the comparator is connected with a driving circuit, a peak difference detector and a follow-up amplifier, the follow-up amplifier is connected with an A/D sampling device which is connected with a CPU processing module and an output sampling device, and the CPU processing module is connected with a display device. The current detection device for the large direct current charge-discharge facility has the advantages that a direct current source with grade of 0.05 or lower than 0.05 can be directly detected, the current detection device can be used as an ideal large high-precision direct current meter used for test in a laboratory, and high precision of the direct current meter is ensured through high-precision resistance array sampling, a signal input A/D sampler and a digital multiplier.
Description
Technical field
The utility model relates to large direct current detection technique field, is specifically related to a kind of large direct current and discharges and recharges facility current sensing means.
Background technology
In the detection of national defence metrology, electric locomotive, electric motor car, accumulator cell charging and discharging, electric welding machine and the detection of various heavy DC instrument, large electric current, the high precision DC ammeter equipment that is absolutely necessary, as the charging and discharging currents of electric motor car, accumulator at 50A～500A; Electric locomotive, subway DC power-supply system DC current be generally in about 3000A, and the Measurement accuracy of DC current is directly connected to the power supply safety of train and security of operation (as the insulation against ground supervision of the current quick of traction rectifier unit, overcurrent protection, direct current positive and negative busbar etc. all needs to carry out accurate measurement, just can play safe guarantee).
For large DC current, there is strong magnetic interference etc. in scene, carry out direct contact type measurement and just seem very difficult, is even difficult to draw result accurately.At present, all pay attention to the research of this respect both at home and abroad, but also do not had at home DC current to reach high precision (precision the reaches 0.02%) DC ammeter of 3000A.
Utility model content
The purpose of this utility model, for having solved the problems referred to above, provides a kind of large direct current to discharge and recharge facility current sensing means, and it had both met the requirement of the test of Liao Ge testing agency, can provide support for the foundation of the measurement standard of every profession and trade again.
For achieving the above object, the utility model provides a kind of large direct current to discharge and recharge facility current sensing means, comprise comparator, described comparator comprises two modulation detection iron cores, described two modulation detection iron core peripheries are all wound with detection winding, described two overlapping placements of modulation detection iron core differential concatenation, described two modulation detection iron core peripheries are successively around upper secondary winding and armature winding, described comparator is connected with exciting circuit, the poor wave detector in peak and follower amplifier, described follower amplifier is connected with A/D sampling thief, this A/D sampling thief is connected with CPU processing module and output sampling device, described CPU processing module is connected with display device.
Concrete, described exciting circuit comprises oscillatory circuit, frequency dividing circuit, power amplifier, described oscillatory circuit comprises time-base integrated circuit NE555 and RC series circuit, this RC series circuit comprises capacitor C 1, resistance R 1, resistance R 2 and the adjustable resistance R3 being connected in series successively, described frequency dividing circuit comprises two rising edge d type flip flop CD4013, described power amplifier comprises two triode C2073, and described two triode C2073 are connected with transformer T respectively.
In addition, the output terminal of described transformer T is drawn a center tap A ground connection.
Further, described follower amplifier comprises power amplification circuit, this power amplification circuit comprises prime amplifier and the expansion current amplifier that boosts being connected with prime amplifier, after the prime amplifier that the signal of the poor wave detector output in this peak forms via General operational amplifier, promote the expansion current amplifier that boosts being formed by high power valve.
In the utility model, one end of the negative pole contact resistance R1 of described prime amplifier, the other end ground connection of this resistance R 1, the described expansion current amplifier that boosts is connected with respectively resistance R 3 and resistance R 4, described resistance R 3 other end ground connection, described prime amplifier is connected in parallel to resistance R 2 with the expansion current amplifier that boosts.
The utlity model has following beneficial effect: the large direct current in utility model discharges and recharges gordian technique and the difficult problem that facility current sensing means is broken through the aspects such as direct current measurement metering and on-line testing, meet the measurement verification/calibration that large direct current is discharged and recharged to facility electric current, it can directly examine and determine 0.05 grade and following other DC current source of level, also can make the large direct current table of desirable high precision for the tests such as laboratory simultaneously, through the sampling of precision resister array, signal input A/D sampling thief and digital multiplier, guarantee the high precision (0.02%) of DC ammeter.
Accompanying drawing explanation
In order to be illustrated more clearly in the utility model embodiment or technical scheme of the prior art, to the accompanying drawing of required use in embodiment or description of the Prior Art be briefly described below, apparently, accompanying drawing in the following describes is only embodiment more of the present utility model, for those of ordinary skills, do not paying under the prerequisite of creative work, can also obtain according to these accompanying drawings other accompanying drawing.
Fig. 1 is the structured flowchart that the large direct current of the utility model discharges and recharges facility current sensing means;
Fig. 2 is the schematic diagram that the large direct current of the utility model discharges and recharges facility current sensing means exciting circuit;
Fig. 3 is the schematic diagram that the large direct current of the utility model discharges and recharges facility current sensing means power amplification circuit;
The oscillogram of the poor wave detector in peak when Fig. 4 is two modulation detection core sataration states of comparator in the utility model;
Fig. 5 is that the large direct current of the utility model discharges and recharges facility current sensing means comparator structural representation.
Embodiment
Below in conjunction with the accompanying drawing in the utility model embodiment, the technical scheme in the utility model embodiment is clearly and completely described, obviously, described embodiment is only the utility model part embodiment, rather than whole embodiment.Embodiment based in the utility model, those of ordinary skills are not making the every other embodiment obtaining under creative work prerequisite, all belong to the scope of the utility model protection.
Referring to Fig. 1, Fig. 2, Fig. 3, shown in Fig. 4 and Fig. 5, the utility model provides a kind of large direct current to discharge and recharge facility current sensing means, comprise comparator 10, described comparator 10 comprises two modulation detection iron cores 1, described two modulation detection iron core 1 peripheries are all wound with and detect winding 2, described two overlapping placements of modulation detection iron core 1 differential concatenation, described two modulation detection iron core 1 peripheries are successively around upper secondary winding 3 and armature winding 4, described comparator 10 is connected with exciting circuit 12, the poor wave detector 11 in peak and follower amplifier 9, described follower amplifier 9 is connected with A/D sampling thief 5, this A/D sampling thief 5 is connected with CPU processing module 6 and output sampling device 8, described CPU processing module 6 is connected with display device 7.
Adopt Magnetically modulated comparator technology, superimposed by double-iron core, the pumping signal producing by exciting circuit again makes two iron cores in approaching state of saturation, when passing through without extraneous electric current, the detection signal taking out from two iron core mid points is processed upper and lower half-wave symmetry status and no signal output, when having extraneous electric current to pass through, there is detection signal output, detection signal is controlled follower amplifier output secondary current and is passed through in the opposite direction iron core, reach ampere-turn equilibrium, secondary current ratio is in primary current, thereby reaches current transformation object; Two are wound with differential concatenation after the overlapping placement of iron core that detects winding, then around upper secondary winding and armature winding.After two detection winding differential concatenations, by modulating oscillator, provide pumping signal, make two iron cores just enter state of saturation.While there is no DC current in iron core ring, due to the identical symmetry of two iron core duties, detuner non-output signal, amplifier non-output signal, now in zero balance state.While passing through DC current on armature winding, detuner produces output signal, and amplifier also produces output signal, makes the output of detuner be tending towards zero point, and at this moment balance is mobile equilibrium, so the course of work of DC comparator is also referred to as tracing process.
As the concrete embodiment of the utility model, described exciting circuit comprises oscillatory circuit, frequency dividing circuit, power amplifier, described oscillatory circuit comprises time-base integrated circuit NE555 and RC series circuit, this RC series circuit comprises capacitor C 1, resistance R 1, resistance R 2 and the adjustable resistance R3 being connected in series successively, described frequency dividing circuit comprises two rising edge d type flip flop CD4013, described power amplifier comprises two triode C2073, and described two triode C2073 are connected with transformer T respectively.Described oscillatory circuit produces square-wave signal, and the frequency of this square-wave signal can regulate by adjustable resistance R3, the Q of this square-wave signal by two rising edge d type flip flop CD4013,
two contrary square-wave signals of end output, these two contrary square-wave signals be used for respectively promoting two brachium pontis of power amplifier and in turn conducting then by transformer T, export and synthesize a complete square-wave signal.Output meets excitation and detects the required pumping signal with certain frequency, amplitude and power of iron core, and this pumping signal passes into detection iron core, and iron core is activated to state of saturation.The output terminal of described transformer T is drawn a center tap A ground connection, and this center tap A forms a reference point, as the reference point of the poor wave detector in rear class peak.
Further, the poor wave detector in described peak be take the poor waveform in peak that center tap A is that reference point produces, and when two modulation detection iron cores are activated to state of saturation, the poor waveform in this peak is amplitude equal and opposite in direction and symmetrical positive negative wave, and now the poor wave detector in peak is exported without direct current; When having forward current to pass through two modulation detection iron cores, it is large that the forward waveforms amplitude of the poor waveform in peak becomes, and the negative sense waveforms amplitude of the poor waveform in peak diminishes, and the poor wave detector output signal in peak is for just; When having negative current to pass through, it is large that the negative sense waveforms amplitude of the poor waveform in peak becomes, and the forward waveforms amplitude of the poor waveform in peak diminishes, and the poor wave detector output signal in peak is for negative.Iron core is excited to state of saturation, and while normally working, will form with A point is the poor waveform of reference peak.Positive and negative (upper and lower) waveforms amplitude equal and opposite in direction is symmetrical, and wave detector is exported without direct current.When having forward current to pass through, it is large that forward waveforms amplitude becomes, and negative sense waveforms amplitude diminishes, and is just output as; Otherwise, be output as negative.The poor wave detector in peak has just detected input current like this, by power amplification output current, follows the tracks of input current, offsets the magnetic flux of tested electric current, reaches dynamic balance state.At this moment equilibrium state is the zero balance state that is different from no current input, and peak is poor slightly asymmetric, and the poor wave detector in peak has certain output, for generation of the electric current I of this output voltage
0be mapping fault (being generally several milliamperes).
Further, described follower amplifier comprises power amplification circuit, this power amplification circuit comprises prime amplifier and the expansion current amplifier that boosts being connected with prime amplifier, after the prime amplifier that the signal of the poor wave detector output in this peak forms via General operational amplifier, promote the expansion current amplifier that boosts being formed by high power valve.One end of the negative pole contact resistance R1 of described prime amplifier, the other end ground connection of this resistance R 1, the described expansion current amplifier that boosts is connected with respectively resistance R 3 and resistance R 4, described resistance R 3 other end ground connection, and described prime amplifier is connected in parallel to resistance R 2 with the expansion current amplifier that boosts.After the preposition amplification that the poor detection output signal in peak forms via General operational amplifier, promote the expansion current amplifier that boosts that high power valve forms.Because the supply voltage of amplifier can not surpass ± 15V, output voltage swing is ± 12V, be generally ± 10mA of output current, can not meet output requirement, adding boosts expand banish large after, can make the output current of DCC-4kA reach ± 1.5A, reach ± 40V of output voltage, reach ± 25V of the output voltage of DCC-600A, reach ± 0.2A of output current, meet work designing requirement.The enlargement factor K=1+R2/R1 of whole power amplifier, design load is about 100, gets R2=100k, R1=1k.Boost to expand and banish most enlargement factor K=1+R4/R3, design load is about 6, gets R4=10k, R3=2k.Prime amplifier enlargement factor K1=100/6, is about 17 times like this.Enlargement factor K is excessive, and amplifier there will be vibration, job insecurity, and enlargement factor is too small, cannot trace into full scale current, cannot keep equilibrium state, occurs unbalance.
In the utility model, described A/D sampling thief is sampled to convert to the balanced balanced current of follower amplifier output and is measured, described comparator secondary balancing output current value is 1A, and the sampling resistor that this comparator output current is 1 Ω via the resistance that in A/D sampling thief, a plurality of resistance forms carries out obtaining the sampled signal of 1V and send into voltage/frequency circuit converting after I/V conversion.It is core that described voltage/frequency circuit adopts monolithic synchronizing voltage-frequency converter A/D652.Reach after ampere-turn equilibrium, the 1A signal of sampling out, and guarantee that conversion precision reaches 0.01%; Secondary current sampling output, the current sample forming with type metal foil type resistance output, can realize the accurate sampling to secondary current, has the feature of high output voltage value, low temperature drift.Voltage/frequency circuit adopts the variable quantity of charge balance technique to complete translation function.Circuit adopts external clock 200kHz to set up full scale frequency, guarantees the stability of conversion.Two adjustable resistances regulate respectively zero-bit and the gain of conversion input.Output full scale (specified) frequency 100kHz drives through pull-up resistor and delivers to that single-chip microcomputer is counted, computing, processes and displays.
Further, described CPU processing module adopt single-chip microcomputer to tested electric current count, computing, processes and displays, transmission.The circuit such as program, data storage, key scanning input, demonstration, RS-232 serial line interface have been expanded.Main task has been tested current value counting, computing, processes and displays, transmission etc.
Numeration computing according to
In formula: Kv: voltage divider no-load voltage ratio; C
1: voltage A/D quantizes constant; Nv: voltage pulse train count value; Kz: DC comparator no-load voltage ratio; C
2: electric current A/D quantizes constant; N
i: current impulse string count value; Δ t: gate time interval.
By the co-ordination of each part mentioned above circuit, just can realize the online non-touch precision measurement of large DC current.On this circuit base, expansion programing function, also can measure other parameter/parameters of direct current.Realize the programme-controlled of measuring process and continuous data teletransmission.
The foregoing is only preferred embodiment of the present utility model; not in order to limit the utility model; all within spirit of the present utility model and principle, any modification of doing, be equal to replacement, improvement etc., within all should being included in protection domain of the present utility model.
Claims (5)
1. large direct current discharges and recharges facility current sensing means, it is characterized in that: comprise comparator, described comparator comprises two modulation detection iron cores, described two modulation detection iron core peripheries are all wound with detection winding, described two overlapping placements of modulation detection iron core differential concatenation, described two modulation detection iron core peripheries are successively around upper secondary winding and armature winding, described comparator is connected with exciting circuit, the poor wave detector in peak and follower amplifier, described follower amplifier is connected with A/D sampling thief, this A/D sampling thief is connected with CPU processing module and output sampling device, described CPU processing module is connected with display device.
2. large direct current according to claim 1 discharges and recharges facility current sensing means, it is characterized in that: described exciting circuit comprises oscillatory circuit, frequency dividing circuit, power amplifier, described oscillatory circuit comprises time-base integrated circuit NE555 and RC series circuit, this RC series circuit comprises capacitor C 1, resistance R 1, resistance R 2 and the adjustable resistance R3 being connected in series successively, described frequency dividing circuit comprises two rising edge d type flip flop CD4013, described power amplifier comprises two triode C2073, and described two triode C2073 are connected with transformer T respectively.
3. large direct current according to claim 2 discharges and recharges facility current sensing means, it is characterized in that: the output terminal of described transformer T is drawn a center tap A ground connection.
4. large direct current according to claim 1 discharges and recharges facility current sensing means, it is characterized in that: described follower amplifier comprises power amplification circuit, this power amplification circuit comprises prime amplifier and the expansion current amplifier that boosts being connected with prime amplifier, after the prime amplifier that the signal of the poor wave detector output in this peak forms via General operational amplifier, promote the expansion current amplifier that boosts being formed by high power valve.
5. large direct current according to claim 4 discharges and recharges facility current sensing means, it is characterized in that: one end of the negative pole contact resistance R1 of described prime amplifier, the other end ground connection of this resistance R 1, the described expansion current amplifier that boosts is connected with respectively resistance R 3 and resistance R 4, described resistance R 3 other end ground connection, described prime amplifier is connected in parallel to resistance R 2 with the expansion current amplifier that boosts.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320695949.9U CN203572875U (en) | 2013-11-05 | 2013-11-05 | Current detection device for large direct current charge-discharge facility |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201320695949.9U CN203572875U (en) | 2013-11-05 | 2013-11-05 | Current detection device for large direct current charge-discharge facility |
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| CN203572875U true CN203572875U (en) | 2014-04-30 |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103543323A (en) * | 2013-11-05 | 2014-01-29 | 云南省计量测试技术研究院 | Current detection device for large direct current charge-discharge facility |
| CN112951670A (en) * | 2019-12-10 | 2021-06-11 | 华为数字技术（苏州）有限公司 | Circuit breaker with current detection function and communication power supply |
-
2013
- 2013-11-05 CN CN201320695949.9U patent/CN203572875U/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103543323A (en) * | 2013-11-05 | 2014-01-29 | 云南省计量测试技术研究院 | Current detection device for large direct current charge-discharge facility |
| CN112951670A (en) * | 2019-12-10 | 2021-06-11 | 华为数字技术（苏州）有限公司 | Circuit breaker with current detection function and communication power supply |
| CN112951670B (en) * | 2019-12-10 | 2024-05-17 | 华为数字能源技术有限公司 | Circuit breaker with current detection function and communication power supply |
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Granted publication date: 20140430 |