CN204374395U - The D.C. isolation monitoring device of signal injection method - Google Patents
The D.C. isolation monitoring device of signal injection method Download PDFInfo
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- CN204374395U CN204374395U CN201520017545.3U CN201520017545U CN204374395U CN 204374395 U CN204374395 U CN 204374395U CN 201520017545 U CN201520017545 U CN 201520017545U CN 204374395 U CN204374395 U CN 204374395U
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- 238000000034 method Methods 0.000 title claims abstract description 21
- 238000002955 isolation Methods 0.000 title claims abstract description 14
- 238000002347 injection Methods 0.000 title claims abstract description 13
- 239000007924 injection Substances 0.000 title claims abstract description 13
- 238000012806 monitoring device Methods 0.000 title claims abstract description 12
- 230000009466 transformation Effects 0.000 claims abstract description 14
- 230000010363 phase shift Effects 0.000 claims abstract description 11
- 230000003321 amplification Effects 0.000 claims abstract description 10
- 238000004458 analytical method Methods 0.000 claims abstract description 10
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- 238000005859 coupling reaction Methods 0.000 claims abstract description 8
- 230000005540 biological transmission Effects 0.000 claims abstract description 7
- 238000009413 insulation Methods 0.000 description 5
- 238000012544 monitoring process Methods 0.000 description 4
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- 230000005611 electricity Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000007935 neutral effect Effects 0.000 description 2
- 230000001131 transforming effect Effects 0.000 description 2
- 208000032368 Device malfunction Diseases 0.000 description 1
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 1
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- 229910052744 lithium Inorganic materials 0.000 description 1
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- 238000013024 troubleshooting Methods 0.000 description 1
Abstract
The application relates to a kind of D.C. isolation monitoring device of signal injection method, and it comprises signal source device and single-phase-to-earth fault analysis device two part.Signal source device after comprising Chip Microcomputer A, Chip Microcomputer A in turn circuit to be connected D/A converter and signal transformation circuit, signal transformation circuit output terminal is divided into two-way, one tunnel connects with signal amplification circuit, signal coupling circuit, DC bus circuit, and another road connects with reference signal circuit, reference source amplifying circuit, wireless transmission output circuit; Single-phase-to-earth fault analysis device comprises current sensor, after current sensor, circuit is connected current signal amplifier circuit, signal filter circuit, signal phase-shift circuit, signal locking circuit, rectification circuit, A/D converter, single-chip microcomputer B, and described signal filter circuit place circuit is connected with reference signal treatment circuit and wireless receiving circuit.The application can be applied to the DC power system of different brackets, different voltage.Principle is simple, sensor cost is lower.
Description
Technical field
The application relates to a kind of instrument of power system device malfunction monitoring, particularly relates to a kind of instrument of electric power DC power system insulated on-line monitoring.
Background technology
DC power system is an earth-free power supply, specially for the automation equipment, communication apparatus, proterctive equipment, primary cut-out etc. of electricity substation provide power supply.Its advantage is except having enough large short-circuit current and uninterrupted power supply, and another topmost reason is that to be different from AC power supply system be isolated neutral system to direct supply, is that power transmission and transformation field utilizes him safer as power-supply unit power supply.DC power system, owing to being earth-free power supply, can not by the interference of ground wire zero potential, solve the Electro Magnetic Compatibility that transforming plant protecting device, automation equipment are good, anti-interference and control to have precedence over AC power completely.Direct supply is formed primarily of charging set, battery pack and feeding line portion, big current can be released because accumulator internal resistance is less, closing operation and proterctive equipment electricity consumption is divided to provide strong guarantee to power high voltage switch, so transforming plant DC power supply is termed again meaning electric operation power, DC power system is earth-free system, can regard as the both positive and negative polarity of direct supply theoretically between the earth being infinitely-great insulation resistance; Between its circuit and the earth without any electrical connection, and due to factors such as supply network, apparatus insulated, wire insulations in actual motion, always there is insulation against ground hydraulic performance decline in the equipment of long-term charging operation, produces grounding phenomenon over the ground.In order to solve DC power system insulation against ground monitoring problem, the product such as D.C. isolation control relay, DC grounding monitor instrument is installed in DC power system.This product is mainly used for judging whether straight-flow system direct current power supply loop defective insulation occurs and produces grounding phenomenon.
The device of current judgement DC system grounding route selection is mainly determined whether earth fault occurs by electric bridge, and branch road route selection have employed Hall current leakage current sensor, magnetic saturation leakage current sensor etc., is used for judging DC power system earth fauit loops.Leakage current sensor in this device is all installed on direct supply feeder assembly, utilizes leakage current sensor to judge to occur the feeder assembly of DC ground fault to the leakage current situation of monitoring direct current branch loop.Because leakage current signal is very weak, the factor of the larger load current of loop current load affects Hall current leakage current sensor, and magnetic saturation sensor causes low precision.Unstable properties problem, adds the problem such as temperature drift, drift of self, usually there will be the wrong report in loop and fail to report phenomenon.Effective solution DC power system grounding fault adopts signal injection method principle, and be grounded troubleshooting and location, not losing is a kind of good method.
Summary of the invention
The object of the application is to propose a kind of in order to earth fault is got rid of, the signal injection method of good measurement effect is played in localizing faults loop D.C. isolation monitoring device.
The object of the application is achieved in that the D.C. isolation monitoring device of signal injection method, and it comprises signal source device and single-phase-to-earth fault analysis device two part.Signal source device after comprising Chip Microcomputer A, Chip Microcomputer A in turn circuit to be connected D/A converter and signal transformation circuit, signal transformation circuit output terminal is divided into two-way, one tunnel connects with signal amplification circuit, signal coupling circuit, DC bus circuit in turn, and another road connects with reference signal circuit, reference source amplifying circuit, wireless transmission output circuit circuit in turn; Single-phase-to-earth fault analysis device comprises current sensor, after current sensor, circuit is connected with current signal amplifier circuit, signal filter circuit, signal phase-shift circuit, signal locking circuit, rectification circuit, A/D converter, single-chip microcomputer B in turn, branch road is provided with at described signal filter circuit place, this branch road comprises wireless receiving circuit and reference signal treatment circuit, and reference signal treatment circuit is connected with signal filter circuit circuit.
Owing to implementing technique scheme, structure is simple, reasonable in design, easy to process compared to existing technology, field adjustable convenient for the application.The DC power system of different brackets, different voltage can be applied to.Principle is simple, sensor cost is lower.To sensor production require low, float low feature without drift, drift, temperature.
Accompanying drawing explanation
The concrete structure of the application is provided by following drawings and Examples:
Fig. 1 is the D.C. isolation monitoring device circuit diagram of signal injection method.
Embodiment
The application by the restriction of following embodiment, can not determine concrete embodiment according to the technical scheme of the application and actual conditions.
Embodiment: as shown in Figure 1, the D.C. isolation monitoring device of signal injection method, it comprises signal source device and single-phase-to-earth fault analysis device two part.
Signal source device after comprising Chip Microcomputer A (1), Chip Microcomputer A (1) in turn circuit to be connected D/A converter (2) and signal transformation circuit (3), signal transformation circuit (3) output terminal is divided into two-way, one tunnel connects with signal amplification circuit (4), signal coupling circuit (5), DC bus (6) circuit in turn, and another road connects with reference signal circuit (7), reference source amplifying circuit (8), wireless transmission output circuit (9) circuit in turn.
Single-phase-to-earth fault analysis device comprises current sensor (10), and after current sensor (10), circuit is connected with current signal amplifier circuit (11), signal filter circuit (12), signal phase-shift circuit (13), signal locking circuit (14), rectification circuit (15), A/D converter (16), single-chip microcomputer B (17) in turn.Be provided with branch road at described signal filter circuit (12) place, this branch road comprises wireless receiving circuit (21) and reference signal treatment circuit (22), and reference signal treatment circuit (22) is connected with signal filter circuit (12) circuit.
Described single-chip microcomputer B(17) also connect with language alarm circuit (18), LCDs (19), photoelectric alarm output circuit (18) circuit respectively.
In use, Chip Microcomputer A (1) in signal source device exports to D/A converter (2) by the signal of a software programming 0.25HZ, the 0.25HZ signal that Chip Microcomputer A (1) produces is become a sinusoidal wave simulating signal by D/A converter (2), Chip Microcomputer A (1) adopts 89C51, D/A converter (2) adopts DA0808, is 8 D/A converters.Its circuit waveform is that the alternated sine-wave signal of 0.25HZ delivers to signal transformation circuit (3), be shaped to the sine wave signal of a standard low frequency, one tunnel is delivered to signal amplification circuit (4) and is carried out signal amplification, the main signal that this road signal detects as leakage current loop, feature low frequency, solves straight-flow system loop ground capacitance interference problem effectively.Another road signal of signal transformation circuit (3) is delivered to reference signal circuit (7) and is formed square-wave signal, the square-wave signal of reference signal circuit is delivered to reference source signal amplifying circuit (8) and is exported, reference source signal amplifying circuit (8) is by square-wave signal by wireless transmission circuit (9), and radio signal frequency is the special signal of general 433.92KHZ.Sent by wireless signal; This wireless signal is as the signal transacting effect of signal receiving device PGC demodulation, Frequency Locking.It is 0.25HZ that the sinusoidal signal of signal transformation circuit (3) is amplified to voltage 5V frequency through the sine wave signal that signal amplification circuit (4) carries out signal amplification, signal amplification circuit (4) makes the power of this sine wave signal reach 5W, guarantees the amplitude requirement of the leakage current of stake resistance.Sine wave signal delivers to the negative pole on DC bus (6) by signal coupling circuit (5).Sine wave signal is mainly fed on DC bus by isolation method by signal coupling circuit (5), the all feeder assemblies on DC bus are made to have sine wave signal when straight-flow system generation earth fault, a leakage current is produced, signal coupling circuit (5) the mainly logical interchange of stopping direct current with the ground loop that earth fault occurs.At this moment sine wave signal coupling DC bus on (6), the working power of Chip Microcomputer A (1) is ground connection, if straight-flow system have produce ground connection time, signal will by stake resistance with the earth form a loop.Signal source device provides this signal and has stable, reliable, and straight-flow system is be in resting state for subsequent use once occur that earth fault signal source is just injected from trend straight-flow system at ordinary times, so can not produce any interference to straight-flow system.
The current sensor (10) of single-phase-to-earth fault analysis device section is installed on each branch feeder loop of direct current cabinet, each branch feeder respectively installs a current sensor (10), each current sensor (10) senses the leakage current signal that stake resistance produces, leakage current signal is delivered to current signal amplifier circuit (11) and is amplified by current sensor (10), this leakage current signal is very faint, is generally a microampere pole.Signal demand amplifies process leakage current signal and approximately amplifies 1000 times are removed non-zero .25HZ afterwards other electric currents by filtering circuit (12), current sensor (10) can sense different grounding resistance, the electric current of other signals of electric capacity and 50HZ, by signal filter circuit (12), phase shift is carried out again by signal phase-shift circuit (13), the leakage current that effective difference loop direct earth capacitance and stake resistance produce, the electric current of direct earth capacitance is ahead of stake resistance signal 90 degree, after sinusoidal wave 0.25HZ current signal leads to the phase shift of phase-shift circuit (13) 90 degree, sine-shaped starting point and zero crossing are matched, the sine wave reference signal that now wireless receiving circuit (21) reception sends wireless 0.25HZ from the wireless transmission output circuit (9) in signal source device compares reference phase, 0.25HZ frequency.The reference source signal that wireless receiving circuit (21) is brought is carried out amplification process by reference signal treatment circuit (22), determines reference signal source.Reference signal is delivered to signal locking circuit (14) and is processed by reference signal treatment circuit (22), signal locking circuit (14) is by the signal after signal phase-shift circuit (13) phase shift, by same phase and frequency synchronous with reference signal and phase-locked, solve other neutral signals because electric capacity Hz noise causes comprehensively, signal locking circuit (14) carries out rectification process by delivering to signal rectifier circuit (15) after semaphore lock, the DC power signal forming a 0-2V delivers to single-chip microcomputer B(18 by after A/D converter (16) analog to digital conversion), single-chip microcomputer B(18) according to the leakage current signal measured, if the ground current signal having stake resistance to form just can calculate and determine leakage current value, the information such as grounding resistance.Single-chip microcomputer B(18) adopt Maxim 16 single chip computer AT 89c55, single-chip microcomputer B(18) relevant data is also undertaken showing different information, single-chip microcomputer B(18 by LCDs (20) with prestige) exported by photoelectric alarm circuit (21) according to different ground signallings.There is alerting signal, the power supply of single-phase-to-earth fault analysis device also can by DC power supply by lithium battery power supply, its leakage current signal is by after phase shift and phase-locked process, wireless receiving to more really the fixing of reference source signal, capacitive, resistive leakage current are successfully distinguished, solve wrong report that capacity earth causes, fail to report, colleague also solves the Hz noise problem of 50HZ.Current sensor (10) can adopt the sensor of open type, can install and not need to have a power failure in the straight-flow system put into operation, and this method is practical reliable.
Above technical characteristic constitutes the most preferred embodiment of the application, and it has stronger adaptability and best implementation result, can increase and decrease inessential technical characteristic according to actual needs, meet the needs of different situations.
Claims (5)
1. the D.C. isolation monitoring device of a signal injection method, it comprises signal source device and single-phase-to-earth fault analysis device two part, it is characterized in that: signal source device after comprising Chip Microcomputer A, Chip Microcomputer A in turn circuit to be connected D/A converter and signal transformation circuit, signal transformation circuit output terminal is divided into two-way, one tunnel connects with signal amplification circuit, signal coupling circuit, DC bus circuit in turn, and another road connects with reference signal circuit, reference source amplifying circuit, wireless transmission output circuit circuit in turn; Single-phase-to-earth fault analysis device comprises current sensor, after current sensor, circuit is connected with current signal amplifier circuit, signal filter circuit, signal phase-shift circuit, signal locking circuit, rectification circuit, A/D converter, single-chip microcomputer B in turn, branch road is provided with at described signal filter circuit place, this branch road comprises wireless receiving circuit and reference signal treatment circuit, and reference signal treatment circuit is connected with signal filter circuit circuit.
2. the D.C. isolation monitoring device of signal injection method as claimed in claim 1, is characterized in that: described single-chip microcomputer B also connects with language alarm circuit, LCDs, photoelectric alarm output circuit circuit respectively.
3. the D.C. isolation monitoring device of signal injection method as claimed in claim 1, it is characterized in that: the signal that Chip Microcomputer A produces is formed as a sinusoidal wave simulating signal by D/A converter, and the simulating signal of this sine wave is shaped to the sine wave signal of a standard low frequency by signal transformation circuit.
4. the D.C. isolation monitoring device of signal injection method as claimed in claim 1, is characterized in that: another road signal of signal transformation circuit is delivered to reference signal circuit and formed square-wave signal.
5. the D.C. isolation monitoring device of signal injection method as claimed in claim 1, it is characterized in that: current sensor is installed on each branch feeder loop of direct current cabinet, each branch feeder respectively installs a current sensor, each current sensor senses the leakage current signal that stake resistance produces, and leakage current signal is delivered to current signal amplifier circuit and amplified by current sensor.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201520017545.3U CN204374395U (en) | 2015-01-12 | 2015-01-12 | The D.C. isolation monitoring device of signal injection method |
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| CN201520017545.3U CN204374395U (en) | 2015-01-12 | 2015-01-12 | The D.C. isolation monitoring device of signal injection method |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109669104A (en) * | 2019-01-29 | 2019-04-23 | 镇江赛尔尼柯自动化有限公司 | A kind of method and its monitoring device based on Injection Signal monitoring ship network system Intelligent insulation state |
| CN115144791A (en) * | 2022-09-06 | 2022-10-04 | 浙江新图维电子科技有限公司 | Method and system for online detection of high-voltage cable armor grounding state |
-
2015
- 2015-01-12 CN CN201520017545.3U patent/CN204374395U/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109669104A (en) * | 2019-01-29 | 2019-04-23 | 镇江赛尔尼柯自动化有限公司 | A kind of method and its monitoring device based on Injection Signal monitoring ship network system Intelligent insulation state |
| CN115144791A (en) * | 2022-09-06 | 2022-10-04 | 浙江新图维电子科技有限公司 | Method and system for online detection of high-voltage cable armor grounding state |
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