CN104749409A - High-speed optical isolation voltage sensor suitable for lightning overvoltage environment - Google Patents
High-speed optical isolation voltage sensor suitable for lightning overvoltage environment Download PDFInfo
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- CN104749409A CN104749409A CN201510171823.5A CN201510171823A CN104749409A CN 104749409 A CN104749409 A CN 104749409A CN 201510171823 A CN201510171823 A CN 201510171823A CN 104749409 A CN104749409 A CN 104749409A
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Abstract
The invention discloses a high-speed optical isolation voltage sensor suitable for a lightning overvoltage environment. The high-speed optical isolation voltage sensor has quite high conversion speed of which the typical value is within 1 microsecond, quite low nonlinearity degree of which the typical value is below 0.01%, quite high precision of which the typical value is within 1% and 1KV isolation voltage. Analog signal attenuation is implemented by the following process that a preceding inputting voltage peak value is greatly reduced through a voltage attenuation unit, reduction of the preceding inputting voltage peak value is implemented by a resistance network, and highest preceding voltage is +/-400V; by a photoelectric conversion isolation system, preceding inputting is separated from later signal acquiring, AD (analog/digital) conversion, data storage and the like, and analog signals are transferred through two photoelectric conversion units; and outputting analog signals of the photoelectric conversion isolation system are amplified and filtered through a signal conditioning unit, and later system acquisition is facilitated.
Description
Technical field
The invention discloses a kind of high-speed light isolation voltage sensor being applicable to lightning surge environment, relate to voltage signal decay, based on unit such as the isolation transmission of high-linearity analogy optocoupler and signal conditions.
Background technology
In data collection and control system, be often in and operate under severe experimental situation condition.Part control system also requires to run incessantly for a long time.For improving interference free performance and the reliability of acquisition system, an effective method adopts analog signal isolating technology, namely manages system under test (SUT) and measuring system to isolate, and only allows measured signal to enter measuring system.This technology is in industry generally used, and common partition method has isolated amplifier method and Phototube Coupling method.
Isolated amplifier adopts magnetic coupling method to make do not have electrical link between the input and output of amplifier usually, but this type of isolation design is complicated, and bandwidth is narrower, and volume is large, cost intensive.
Phototube Coupling is conventional and partition method easily and effectively, and it extracts other signal by obtaining light signal, and due to its fast response time, the feature such as highly sensitive, subsequent conditioning circuit simple, low price is now widely used in many scientific domains.
Summary of the invention
The object of this invention is to provide a kind of high-speed light isolation voltage sensor, be applicable to such as lightning surge and gather occasion etc., input signal of can decaying at a high speed sends into rear level system, the safety of level system after ensureing, and can Automatic Optimal signal waveform, carry out the process such as signal amplification, filtering.
The present invention is by the following technical solutions to achieve these goals:
High-speed light isolation voltage sensor, it mainly applies to lightning surge field, by following process implementation from simulating signal decay, opto-electronic conversion, optical signal transmission, signal condition to the whole function of rear class acquisition system:
(1) by voltage attenuation unit (adopting resistor network to realize, the highest front step voltage ± 400V), prime input voltage peak value is significantly reduced.This network degradation coefficient is fine-tuning, and representative value is 200:1.
(2) for meeting the measurement of thunder and lightning up to the high-frequency signal of 0 ~ 1MHz, in the design, add impact damper and forward bias unit, by opto-electronic conversion shielding system, complete the isolation transmission of electric signal, isolation voltage can reach 1Kv.Effectively high-voltage signal and acquisition system are kept apart, make collection Measurement channel avoid the harm of high-voltage signal.
(3) by signal condition unit by the outputting analog signal of opto-electronic conversion shielding system amplify, filtering, be convenient to rear class system acquisition.
It has high slewing rate, 1KV isolation voltage and 1% precision conditions under its voltage transitions speed within 1us, signal bandwidth, at more than 1MHz, can capture the signal of lightning surge, and by the original analog voltage signal of-400V to ﹢ 400V isolation decay 40 times.
It has ultralow nonlinearity, and its representative value is 0.01%.
Its transmission error is less than 1%.
Realize based on resistor network, prime input signal can up to ± 400V, and attenuation coefficient is fine-tuning, and representative value is 200:1.
This system is made up of two photoelectric conversion units, i.e. prime photoelectric conversion unit and rear class photoelectric conversion unit.Wherein, the integrated automatic non-linear compensation circuit based on negative-feedback technology of prime photoelectric conversion unit; Rear class photoelectric conversion unit comprises a circuit/voltage conversion circuit.Signal will add direct current biasing before passing into this system, after this system, coupled, namely remove direct current biasing.In addition this opto-electronic conversion shielding system, has a bypass isolating switch and realizes straight-through function, so that under some specific occasion, do not make to use up isolation and directly carry simulating signal.
This conditioning module carries out signal condition for special rear level system, meets signal output area within ± 10V.Be integrated with 5X signal amplification circuit (this gain can manual adjustments) and 1MHz4 rank low-pass filter.
The attenuator of described voltage attenuation unit comprises resistance R1 and the resistance R3 of series connection, and attenuation coefficient fine-adjusting unit comprises in parallel with R3 with swept resistance VR1, and the linkage section of swept resistance VR1 and resistance R1 is drawn and exported.
For meeting the measurement of thunder and lightning high-frequency signal (0 ~ 1MHz), the design adopts operational amplifier to make impact damper, reverse totalizer is formed again, for +/-simulating signal adds bias voltage, so that +/-simulating signal is done opto-electronic conversion by optocoupler by another operational amplifier and R2, R6, R7.
Its opto-electronic conversion isolated location comprises prime photoelectric conversion module and rear class photoelectric conversion module, prime photoelectric conversion module comprises triode Q1(2N3906), triode Q2(2N3904), AlGaAs LED and input a photodiode PD1 and pull-up resistor network
Triode Q1(2N3906) base stage one end is connected with input photodiode PD1 negative electrode, other end ground connection, and the transmitter of triode Q1 meets power supply VCC by resistance R3, the grounded collector of triode Q1,
The base stage of triode Q2 connects the emitter of triode Q1, and collector meets power supply VCC by AlGaAs LED, and emitter is by resistance R4 ground connection;
AlGaAs LED carries out photoelectric coupling with input photodiode PD1, carries out negative feedback compensation to the base current of triode Q1.
Its rear class photoelectric conversion module comprises input photodiode PD2, triode Q3, triode Q4, resistance R2, resistance R5, resistance R7, the base stage of triode Q3 is by input photodiode PD2 ground connection, triode Q3 emitter meets power supply VCC by resistance R5, grounded collector, the collector of triode Q4 meets power supply VCC by resistance R7, emitter is by resistance R6 ground connection, and the collector of triode Q4 is drawn and exported.
Also comprise the bypass isolating switch of an alternative opto-electronic conversion isolated location.
Specific implementation process is, by the resistor network of voltage attenuation unit, decay to the prime input voltage of magnitude of voltage at ± 400V, this network degradation coefficient is fine-tuning, and representative value is 200:1.By the prime photoelectric conversion unit of opto-electronic conversion shielding system, after voltage signal is increased direct current biasing, be converted to light signal.This optical signals one is non-linear based on the automatic non-linear compensation circuit correction of negative-feedback technology.Receive this light signal by the rear class photoelectric conversion unit of opto-electronic conversion shielding system, by its distinctive circuit/voltage conversion circuit coating-forming voltage signal, and export after removing its direct current biasing.Finally by signal condition unit, amplification filtering is carried out to the outputting analog signal of opto-electronic conversion shielding system, be convenient to rear class system acquisition.
By this design, when can be implemented in guarantee rear class security of system, guarantee the authenticity of the overvoltage signal conversion of test site.
Because the present invention adopts above technical scheme, therefore possess following beneficial effect:
Below technical scheme of the present invention and invention main points:
Attenuator: in high-voltage signal is measured, for convenience of rear class signal regulations and measurement, high-voltage signal need being decayed into small-signal, inputting and the isolation of rear class signal for meeting prime +/-400V in the design, adopt attenuation coefficient to be the resistor network of 200:1, this attenuation coefficient is fine-tuning.
Opto-electronic conversion shielding system: semiconductor photoelectric device is the photoelectric device that conventional optics technology and modern microelectronic technology are combined closely and developed, it extracts other signal by obtaining light signal, because the features such as its fast response time, highly sensitive, subsequent conditioning circuit are simple, low price are now widely used in many scientific domains.In the design of the application, for meeting the measurement of thunder and lightning up to the high-frequency signal of 0 ~ 1MHz, in the design, add impact damper and forward bias unit, high precision linear light coupling is adopted to construct two photoelectric conversion units again, i.e. prime photoelectric conversion unit and rear class photoelectric conversion unit.The wherein integrated negative-feedback circuit of prime photoelectric conversion unit, utilize input optical diode to detect LED light output quantity, adjustment is by the electric current of LED automatically, with the change of compensation LED light output and other reason any cause non-linear.Integrated LED current/the voltage conversion circuit of rear class photoelectric conversion unit, can form analog signal output to rear class acquisition system.In addition, for ensureing the positive and negative simulating signal integrality gathered, before signal coupling, adding forward bias, after signal coupling, remove added bias voltage.In addition this opto-electronic conversion shielding system, have a bypass isolating switch and realize straight-through function, so that under some specific occasion, tester can not make to use up isolation and directly carry simulating signal.
Signal condition unit: in order to the signal to noise ratio (S/N ratio) obtained, the high interference that satisfied ± 10V signal exports and filters outside bandwidth, in signal condition, increases 5X signal amplification circuit and 1MHz 4 rank low-pass filter.
Based on above three gordian techniquies, make by high-speed light isolation voltage sensor, can be the signal that high-voltage signal is converted to the collection of applicable lower system safely, and ensure this signal integrity and accuracy.
Accompanying drawing explanation
Fig. 1 is general principles figure of the present invention;
Fig. 2 is voltage attenuation unit schematic diagram of the present invention;
Fig. 3 voltage attenuation element circuit of the present invention figure;
Fig. 4 impact damper of the present invention and increment biasing circuit figure;
Fig. 5 opto-electronic conversion shielding system of the present invention schematic diagram;
Fig. 6 opto-electronic conversion shielding system of the present invention circuit diagram;
Fig. 7 signal condition unit of the present invention schematic diagram;
Fig. 8 is Phototube Coupling Principle of Process figure of the present invention;
Fig. 9 is the frequency response curve figure of present system.
Embodiment
Below in conjunction with accompanying drawing, also by best embodiment, the present invention is described in detail.
Consult Fig. 1, first set forth the overall operation flow process of this high-speed light isolation voltage sensor.
By the resistor network of voltage attenuation unit, decay to the prime input voltage of magnitude of voltage at ± 400V, this network degradation coefficient is fine-tuning, and representative value is 200:1.By the prime photoelectric conversion unit of opto-electronic conversion shielding system, after voltage signal is increased direct current biasing, be converted to light signal.Receive this light signal by the rear class photoelectric conversion unit of opto-electronic conversion shielding system, by its distinctive circuit/voltage conversion circuit coating-forming voltage signal, and export after removing its direct current biasing.Finally by signal condition unit, amplification filtering is carried out to the outputting analog signal of opto-electronic conversion shielding system, be convenient to rear class system acquisition.
Consult Fig. 2, set forth voltage attenuation unit schematic diagram of the present invention emphatically.
Shown in figure, the simulating signal of experimental field will pass into voltage attenuation unit by shielding passage, to avoid disturb by external signal.After this this simulating signal will pass into a signal attenuator, and this attenuator can be decayed to the front step voltage of magnitude of voltage within ± 400V.Its typical attenuation coefficient is 200:1.In addition, this attenuation coefficient adjusts by a fine-adjusting unit.After this reduced analog signal will be admitted to opto-electronic conversion isolation module.
Consult Fig. 3, set forth voltage attenuation element circuit figure of the present invention emphatically.
Shown in figure, in the design for meeting prime ceiling voltage be ± original analog of 400V and the isolation of rear class signal, adopt 200:1 resistance decrement network, this attenuation network comprises two fixed resistances, R1, R3.Its resistance is respectively 300K Ω and 4.7K Ω, and variohm (EVM3ESX50B53) VR1, this variohm makes attenuation coefficient fine-tuning.
Consult Fig. 4, set forth impact damper of the present invention and increment biasing circuit figure emphatically
In the design, adopt high precision linear light coupling, but in the opto-electronic conversion application of traditional common, single optocoupler can only change unidirectional electrical signal, and, switching signal smaller bandwidth (being about: 0 ~ 150KHz), for meeting the measurement of thunder and lightning high-frequency signal (0 ~ 1MHz), in the design, first impact damper is made with U2A, reverse totalizer is formed again, for +/-simulating signal adds bias voltage, so that +/-simulating signal is done opto-electronic conversion by optocoupler by U2B and R2, R6, R7.This design makes measuring-signal bandwidth reach 1MHz, effectively collecting the transient changing of high-voltage signal, becoming in analyzing high-voltage signal more accurately.
Consult Fig. 5, set forth opto-electronic conversion shielding system principle of the present invention emphatically.
Shown in figure, first the reduced analog signal exported by voltage attenuation unit will enter an impact damper and carry out impedance matching.After this simulating signal will be admitted to direct current biasing unit.
Note, in some special applications, tester can select not make to use up isolation by by-pass switch, directly be sent to rear class by put-through channel, before feeding rear class system unit, this simulating signal also will carry out cushioning and zeroing work, to ensure the requirement of the suitable rear level system of signal.
After being applied with suitable direct current (DC) bias to simulating signal, at signal input light every being converted into suitable light signal, after this exporting light by signal and being converted to simulating signal again every reception, sending into rear class buffering/zeroing unit.
In rear class buffering/zeroing unit, signal will remove direct current biasing, and carry out impedance matching, form light and send into signal condition unit every signal.
Consult Fig. 6, set forth opto-electronic conversion shielding system circuit of the present invention emphatically.
Form electric-light conversion circuit with Q1, Q2, U3A, R101, R8, R2, convert simulating signal to light signal; Form light-electric receiving circuit by U3C, Q3, Q4, R9, R4, R5, receive the light signal after simulating signal conversion, to realize the light isolation of signal front stage; Separately form a negative-feedback circuit by U3B and R10, the non-linear conversion circuit caused with the change and other reason any that compensate U3A light output.
Consult Fig. 7 and set forth conditioning unit schematic diagram of the present invention emphatically.
Shown in figure, first light will pass through a signal amplification unit every signal, and it amplifies representative value is 5 times of amplifications, and this signal amplification unit will be subject to the control of a gain rectifier, and can by tester according to field condition manual adjustments, to ensure the linear of signal gain.After this high frequency interference outside filtered signal bandwidth, signal by enter 1MHz 4 rank low-pass filter filtering after, be treated to safety signal via impact damper and deliver to rear level system.
Consult Fig. 8, emphasis sets forth high-linearity analogy optocoupler schematic diagram of the present invention.
Shown in figure, the design's center heart isolated part adopts HCNR201 high-linearity analogy optocoupler to isolate transmission of analogue signal, in prime module, optocoupler includes the input photodiode (PD1) of a high-performance AlGaAs LED and matched, this photodiode will with monitoring and stablizing AlGaAs LED output brightness in optocoupler operational process, have benefited from this, the light output of AlGaAs LED is non-linear and drift characteristic is almost nil.In post-module, comprise an output photoelectric diode (PD2) in this optocoupler, the light output of AlGaAs LED can be converted to photocurrent by this photodiode, and this transfer process defers to linear change completely.The prime of this optocoupler/post-module adopts a kind of very special encapsulation technology, makes AlGaAs LED and two photodiode (PD1, PD2) can tight fit, and disturbs without any external stray light.When AlGaAs LED is in the luminous course of work, the LED light output quantity that PD1 and PD2 receives completely linearly.
The technical characteristics of this optocoupler is as wanted following points:
0.01% ultralow nonlinearity
K3 (IPD2/IPD1) conversion gain +/-1%
-65 ppm/ ° of C low gain temperatures coefficient
DC to > 1MHz high bandwidth
By appeal several features, HCNR201 high-linearity analogy optocoupler ensure that gain stability and the linearity, is applicable to the field engineering carrying out lightning surge collection.
Consult Fig. 9, emphasis sets forth the frequency response curve figure of present system.
Owing to being added with forward bias voltage in circuit when opto-electronic conversion before, after the conversion of flashlight electric isolution, add a reversed bias voltage, the forward bias before removing in circuit, add the driving intensity that impact damper increases signal, so that the signal to noise ratio (S/N ratio) of the further elevator system of rear class modulate circuit.
Claims (5)
1. be applicable to a high-speed light isolation voltage sensor for lightning surge environment, it is characterized in that comprising:
Voltage transformer (VT): convert line voltage information to simulating signal;
Voltage attenuation unit: comprise connected attenuator and attenuation coefficient fine-adjusting unit, reduces the voltage peak of prime input;
Buffering/forward bias unit: forward bias is carried out to the voltage after voltage attenuation unit
Opto-electronic conversion isolated location: by photoelectric coupling effect, completes the isolation transmission of electric signal;
Signal condition unit: outputting analog signal amplifies, filtering, is convenient to rear class system acquisition.
2. one according to claim 1 is applicable to lightning surge environment at high-speed light isolation voltage sensor, it is characterized in that, the attenuator of described voltage attenuation unit comprises resistance R1 and the resistance R3 of series connection, attenuation coefficient fine-adjusting unit comprises in parallel with R3 with swept resistance VR1, and the linkage section of swept resistance VR1 and resistance R1 is drawn and exported.
3. a kind of high-speed light isolation voltage sensor being applicable to lightning surge environment according to claim 1, it is characterized in that, opto-electronic conversion isolated location comprises prime photoelectric conversion module and rear class photoelectric conversion module, prime photoelectric conversion module comprises triode Q1(2N3906), triode Q2(2N3904), AlGaAs LED and input a photodiode PD1 and pull-up resistor network
Triode Q1(2N3906) base stage one end is connected with input photodiode PD1 negative electrode, other end ground connection, and the transmitter of triode Q1 meets power supply VCC by resistance R3, the grounded collector of triode Q1,
The base stage of triode Q2 connects the emitter of triode Q1, and collector meets power supply VCC by AlGaAs LED, and emitter is by resistance R4 ground connection;
AlGaAs LED carries out photoelectric coupling with input photodiode PD1, carries out negative feedback compensation to the base current of triode Q1.
4. a kind of high-speed light isolation voltage sensor being applicable to lightning surge environment according to claim 3, it is characterized in that, rear class photoelectric conversion module comprises input photodiode PD2, triode Q3, triode Q4, resistance R2, resistance R5, resistance R7, the base stage of triode Q3 is by input photodiode PD2 ground connection, triode Q3 emitter meets power supply VCC by resistance R5, grounded collector, the collector of triode Q4 meets power supply VCC by resistance R7, emitter is by resistance R6 ground connection, and the collector of triode Q4 is drawn and exported.
5. a kind of high-speed light isolation voltage sensor being applicable to lightning surge environment according to claim 1, is characterized in that, also comprise the bypass isolating switch of an alternative opto-electronic conversion isolated location.
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| CN201510171823.5A CN104749409A (en) | 2015-04-13 | 2015-04-13 | High-speed optical isolation voltage sensor suitable for lightning overvoltage environment |
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Citations (5)
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| CN101666826A (en) * | 2009-09-27 | 2010-03-10 | 陕西电力科学研究院 | Overvoltage online monitoring device based on dual time base sampling technology |
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| CN203675088U (en) * | 2014-01-25 | 2014-06-25 | 济南诺辉节能技术开发有限公司 | High-precision voltage-current isolated conversion module |
| CN204631100U (en) * | 2015-04-13 | 2015-09-09 | 四川拓普测控科技有限公司 | Be applicable to the high-speed light isolation voltage sensor of lightning surge environment |
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2015
- 2015-04-13 CN CN201510171823.5A patent/CN104749409A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN101666826A (en) * | 2009-09-27 | 2010-03-10 | 陕西电力科学研究院 | Overvoltage online monitoring device based on dual time base sampling technology |
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| CN102590604A (en) * | 2012-03-21 | 2012-07-18 | 西北工业大学 | Wide voltage data collection device based on complex programmable logic device (CPLD) |
| CN203675088U (en) * | 2014-01-25 | 2014-06-25 | 济南诺辉节能技术开发有限公司 | High-precision voltage-current isolated conversion module |
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Application publication date: 20150701 |