A kind of electronic current mutual inductor that adopts Optical Fiber Transmission simulating signalTechnical field
An electronic current mutual inductor that adopts Optical Fiber Transmission simulating signal, belongs to field of power.
Background technology
In electrical production, electrical power transmission system and power equipment, coordinate instrument, protector measuring electric current and electric energy with mutual inductor, measuring power system each several part institute's consuming electric power and protection safe operation of power system.At present, electric system is used traditional electromagnetic current transducer (CT), electromagnetic potential transformer (PT) to measure electric current, voltage T&B, and is still the main product that current power system is used.But concerning intelligent secondary device of modern times, its output capacity is unnecessary far away, in addition, along with improving constantly of voltage class of electric power system, the power capacity of transmission is increasing, and traditional electromagnetic type electric current, voltage transformer (VT) occur himself unsurmountable problem because of its sensor mechanism.
Along with the development of computer technology, power automation technology, many new technologies, new unit start application in electric system.Voltage current transformer is substantially the most also most important checkout equipment as power monitoring, and the development of its correlation technique and application are more and more subject to people's attention.The development of electromagnetic technique, has improved the performance such as the linearity, antisaturation degree of electromagnetic current transducer greatly, and the employing of computer technology has promoted birth and the development of electronic current mutual inductor.The development of Light Information Science and Technology, makes again Optical Fiber Transmission obtain widespread use in electric system.
Along with the intelligentized development of electrical network, the substitute products of many traditional mutual inductors are there are.The current current transformer generally adopting or releasing mainly contains:
1) traditional electromagnetic current transducer.Output capacity is large, stable performance, but there is High-Voltage Insulation, oil-containing blast, electromagnetic interference (EMI), secondary output open circuit, volume is large, energy consumption is high, high in cost of production shortcoming.
2) utilize the low-power small-signal current mutual inductor of Luo-coil or iron-core coil, send signal to secondary device by Shielded Twisted Pair.Although solved the shortcoming that traditional mutual inductor volume is large, energy consumption is high, cost is high, but still had poor anti jamming capability, cannot realize the shortcomings such as the electrical isolation with high-pressure system.
3) utilize the optical current mutual inductor of Faraday effect, be called again passive electrical minor current transformer.Optical current mutual inductor is divided into again magneto-opitcal current transducer and all-fiber current transformator.Magneto-opitcal current transducer is under the outdoor rugged surroundings of high voltage substation, electric field, temperature, vibration etc. are very large to its performance impact, reflect long term drift in time, the long-time stability of magneto-opitcal current transducer are to affect its final practical key issue, are also problems not being resolved so far.All-fiber current transformator, except Measurement sensibility, reliability are difficult to ensure, is also difficult to be promoted use because it needs the optical device of the costliness such as laser diode, polarization maintaining optical fibre.
4) Active Electronic Current Transformer is the mutual inductor that degree of being practical is higher.The power supply mode that adopts large electric current CT function and little electric current laser function to combine, and by electronic circuit, analog current signal is converted to digital signal, be light pulse through opto-electronic conversion, by optical fiber, digital data transmission to low pressure is surveyed.It is simple that its low pressure is surveyed receiving circuit, can be directly and computing machine carry out data communication.But the analog to digital conversion that its high pressure is surveyed need to be sampled and sequential control, circuit complexity, energy consumption are high, need laser energy supply, and Laser Devices cost is high, and the life-span is short.The digital signal of output, is limited by sample frequency, and frequency band is limited, is unfavorable for failure message monitoring.
Summary of the invention
The technical problem to be solved in the present invention is: overcome the deficiencies in the prior art, a kind of electronic current mutual inductor that adopts Optical Fiber Transmission simulating signal is provided, this electronic current mutual inductor is measured accurate, cheap, and can realize by optical fiber the transmission of analog current signal, the traditional primary side current mutual inductor connecting by cable and secondary side current mutual inductor in alternative electrical power distribution automatization system.
The technical solution adopted for the present invention to solve the technical problems is: the electronic current mutual inductor of this employing Optical Fiber Transmission simulating signal, is characterized in that: comprising:
Light transmitting terminal, the input end of circuit primary side analog current signal access light transmitting terminal is exported light signal by the output terminal of light transmitting terminal after the internal conversion of light transmitting terminal is light signal;
Optical receiving end, its input end is connected with the output terminal of light transmitting terminal, receives the light signal that light transmitting terminal sends, and the light signal receiving is converted to electric signal, and electric signal is compensated to rear output;
And optical fiber, for connecting the output terminal of optical receiving end input end and light transmitting terminal.
Preferably, described light transmitting terminal comprises:
One solenoid, its input end line attachment primary side analog current signal;
One signal integration circuit, its input end is connected with the output terminal of solenoid, and the analog current signal of solenoid output is superposeed;
One feed circuit, its input end is connected with the output terminal of solenoid simultaneously, and its output terminal is connected with signal integration circuit, for light transmitting terminal is powered;
One electric signal switching emission module, its signal input part is connected with the output terminal of signal integration circuit, and it is connected with the output terminal of feed circuit for electrical input, and its output terminal connects optical fiber, and the signal after the stack of signal integration circuit is changed, exported.
Preferably, described signal integration circuit comprises:
One current signal Acquisition Circuit, its input end is connected with the output terminal of solenoid, for obtaining the analog current signal waiting for transmission of the solenoid output line output of going forward side by side;
One scale signal generation module, generates the scale signal matching with analog current signal waiting for transmission;
One signal mixed circuit, its input end is connected with the output terminal of current signal Acquisition Circuit and scale signal generation module respectively, its output terminal is connected with the input end of described electric signal switching emission module, the analog current signal waiting for transmission of current signal Acquisition Circuit output and scale signal generation module generation scale signal are superposeed, make it to become mixing electric signal;
Current signal Acquisition Circuit, scale signal generation module, signal mixed circuit are all connected with described feed circuit and by its power supply.
Preferably, described electric signal switching emission module comprises:
One electro-optical conversion circuit, its input end is connected with the output terminal of signal mixed circuit, and the mixing electric signal of signal mixed circuit output is converted to light signal;
One smooth emission port, for connecting electro-optical conversion circuit and optical fiber, the light signal that electro-optical conversion circuit is converted to is exported;
Electro-optical conversion circuit and electric signal switching emission module are all connected with described feed circuit and by its power supply.
Preferably, described scale signal generation module comprises: direct current scale signal generation module and interchange scale signal generation module;
Exchange scale generation module and realized by sine-wave generator, exchange scale signal in order to generate; Direct current scale signal generation module is used for generating direct current scale signal.
Preferably, described feed circuit comprise:
One power-supply circuit, its input end is connected with the output terminal of solenoid, is provided with rectification circuit and mu balanced circuit in it, and the current source signal that solenoid is obtained is carried out rectification, is converted to voltage source signal;
One energy-storage travelling wave tube, for storage of electrical energy;
One stabilized voltage supply, its output terminal is connected with described current signal Acquisition Circuit, scale signal generation module, signal mixed circuit, electro-optical conversion circuit and electric signal switching emission module, for exporting the required voltage of its work;
An and management of charging and discharging module, its input end is connected with the output terminal of power-supply circuit, its output terminal is connected with the input end of energy-storage travelling wave tube and stabilized voltage supply respectively, and the voltage that management of charging and discharging module adopts MCU to realize management of charging and discharging to energy-storage travelling wave tube and stabilized voltage supply is inputted.
Preferably, described optical receiving end comprises:
One light signal receives modular converter, and its input end is connected with light transmitting terminal by optical fiber, for receiving the light signal that light transmitting terminal sends and the light signal receiving being changed;
One signal conditioning circuit, its input end is connected with the output terminal that light signal receives modular converter, and the signal receiving is separated, compensates, exported.
Preferably, described light signal reception modular converter comprises:
Light-receiving port, is connected with optical fiber, is connected with light transmitting terminal by optical fiber;
Photoelectric switching circuit, its input end is connected with light-receiving port, light-receiving port is received light signal be converted to electric signal and export signal conditioning circuit to.
Preferably, described signal conditioning circuit comprises:
One demultiplexing circuit, its input end is connected with the output terminal of photoelectric switching circuit, and the electric signal of photoelectric switching circuit output is separated, and separates and obtains analog current signal and scale signal;
One gain control circuit, its input end is connected with the output terminal of demultiplexing circuit, receive demultiplexing circuit and separate the scale signal obtaining, and calculate the attenuation coefficient of scale signal in transmitting procedure, and attenuation coefficient is exported as gain control signal;
One signal tracking circuit, its input end is connected with the output terminal of demultiplexing circuit, receive demultiplexing circuit and separate the analog current signal obtaining, the gain control signal of signal tracking circuit receiving gain control circuit output simultaneously, is compensated, exports the analog current signal receiving by gain control signal.
Preferably, be also provided with a standard signal output circuit in described optical receiving end, its input end is connected with the output terminal of signal conditioning circuit.
Key of the present invention is that working power directly takes from line current, accepted scale signal is calibrated the current signal gathering, and by Optical Fiber Transmission simulating signal, this simulating signal is fully reacted circuit current status one time, ensure that the useful raw information of tested electric current is undistorted not lose.
Compared with prior art, the beneficial effect that the present invention has is:
1, can directly realize by optical fiber the transmission of analog current signal, compared with digital data transmission more complete reflection the virgin state of line current, ensureing that the useful raw information of tested electric current is undistorted does not lose, particularly line fault information is had to more complete reservation, be conducive to electric signal to be analyzed.
2, adopt the scale signal carrying to calibrate gathered current signal, thereby greatly improve the measuring accuracy of current signal.
3, Optical Fiber Transmission has been cut off the electrical communication of circuit and secondary terminals device completely, has solved the High-Voltage Insulation that traditional mutual inductor exists and has punctured risk.
4, in light transmitting terminal, be provided with feed circuit, the electric current that solenoid is collected nurse one's health after as power supply, having solved existing electronic mutual inductor need to provide the defect of working power in addition.
5, in feed circuit, be provided with management of charging and discharging module, adopt super capacitor as energy-storage travelling wave tube, can carry out intelligent management to discharging and recharging of energy-storage travelling wave tube, improved the security of power supply.
6, be only provided with light transmitting terminal, optical receiving end and optical fiber, have advantages of simple in structure, cost is low and low power consuming.
Brief description of the drawings
Fig. 1 is the electronic current mutual inductor functional-block diagram that adopts Optical Fiber Transmission simulating signal.
Fig. 2 is the electronic current mutual inductor light transmitting terminal functional-block diagram that adopts Optical Fiber Transmission simulating signal.
Fig. 3 is the electronic current mutual inductor optical receiving end functional-block diagram that adopts Optical Fiber Transmission simulating signal.
Wherein: 1, light transmitting terminal 2, optical receiving end 3, optical fiber.
Embodiment
Fig. 1 ~ 3rd, most preferred embodiment of the present invention, below in conjunction with accompanying drawing 1 ~ 3, the present invention will be further described.
As shown in Figure 1, a kind of electronic current mutual inductor that adopts Optical Fiber Transmission simulating signal, comprises light transmitting terminal 1, optical receiving end 2 and connects the optical fiber 3 of light transmitting terminal 1 and optical receiving end 2.Light transmitting terminal 1 is for realizing conversion and the transmission of primary side analog current signal to light signal; Optical receiving end 2 is for realizing reception, conversion and the compensation of light signal to secondary side current signal; Optical fiber 3 is for realizing the transmission of light signal, thereby realizes analog current signal from once measuring the transmission of secondary side.
Light transmitting terminal 1 comprises solenoid, signal integration circuit, feed circuit and electric signal switching emission module, the input end access primary side analog current signal of solenoid, its output terminal is connected with signal integration circuit and feed circuit respectively, the output terminal of signal integration circuit and feed circuit is connected with the signal input part of electric signal switching emission module and for electrical input respectively, and the output terminal of feed circuit is connected with the electrical input that supplies of signal integration circuit simultaneously.The output terminal of electric signal switching emission module connects optical fiber 3.The primary side analog current signal receiving is delivered to respectively signal integration circuit and feed circuit by solenoid.Analog current signal is sent into the input power as feed circuit after feed circuit, realizes the power supply to signal integration circuit and electric signal switching emission module by feed circuit.After primary side analog current signal is sent into signal integration circuit, signal integration circuit is integrated primary side analog current signal and the scale signal forming in it to form and is mixed electric signal, then mixing electric signal being sent into the internal conversion of electric signal switching emission module is light signal, then by electric signal switching emission module, light signal is sent into optical fiber 3, transmitted by optical fiber 3.
Optical receiving end 2 comprises that light signal receives modular converter, signal conditioning circuit and standard signal output circuit.Light signal receives modular converter and is connected with optical fiber 3, the light signal being sent by light transmitting terminal 1 receives modular converter by light signal and receives after optical fiber 3 transmits, light signal reception modular converter is converted to mixing electric signal by light signal after receiving light signal, then mixing electric signal is sent into signal conditioning circuit.After mixing in electric signal entering signal modulate circuit, mixing electric signal is separated, isolate scale signal and analog current signal.Because light signal there will be decay to a certain degree in transmitting procedure, the mixing electric signal being therefore converted to by signal conditioning circuit and all had the decay of same degree by the isolated scale signal of this mixed light signal and transmission of electric signals.After the analog current signal that signal conditioning circuit obtains separation compensates, make it to revert in light transmitting terminal 1 the primary side analog current signal line output of going forward side by side, complete the Optical Fiber Transmission of analog current signal.
In the functional-block diagram of the light transmitting terminal 1 shown in Fig. 2, black arrow is for representing the direction of transfer of analog current signal, and white arrow is for representing the direction of power supply signal.Feed circuit in above-mentioned light transmitting terminal 1 comprise: power-supply circuit, management of charging and discharging module, stabilized voltage supply and energy-storage travelling wave tube.The output terminal of solenoid is connected with the input end of power-supply circuit, the stabilivolt that power-supply circuit comprises full-wave rectifying circuit and is connected with full-wave rectifying circuit, and be provided with the high power transistor for the unnecessary large electric current of releasing.By power-supply circuit, the ac current signal of solenoid output is converted to galvanic current and presses signal.The voltage output end of power-supply circuit is connected with management of charging and discharging module, and management of charging and discharging module is connected with the input end of energy-storage travelling wave tube and stabilized voltage supply, realizes rationally discharging and recharging energy-storage travelling wave tube by management of charging and discharging module.Under normal circumstances, the voltage of the voltage output end output of power-supply circuit on stabilized voltage supply, obtains stable operating voltage by stabilized voltage supply by management of charging and discharging module loading.In the time reaching charge condition; realize the charging of power-supply circuit to energy-storage travelling wave tube by management of charging and discharging module; after charging completes; management of charging and discharging module stops power-supply circuit energy-storage travelling wave tube is charged; can reasonably charge to energy-storage travelling wave tube by management of charging and discharging module; prevent that it from overcharging, and plays a protective role to energy-storage travelling wave tube.Disappear or amplitude lower in the situation that at primary side analog current signal, the electric energy that energy-storage travelling wave tube stores provides input service voltage for mu balanced circuit, energy-storage travelling wave tube transfers discharge condition to, management of charging and discharging module is monitored energy-storage travelling wave tube sparking voltage, enough in the situation that, control energy-storage travelling wave tube and proceed to charged state lower than setting value and primary side input current at voltage.Discharging and recharging conversion completes automatically.In the electronic current mutual inductor of this employing Optical Fiber Transmission simulating signal, energy-storage travelling wave tube adopts super capacitor to realize, and also can adopt other forms of energy-storage travelling wave tube, as lithium battery.
Signal conditioning circuit in above-mentioned light transmitting terminal 1 comprises: direct current scale generation module, interchange scale generation module and signal mixed circuit.The power output end of the stabilized voltage supply in feed circuit is connected with direct current scale generation module, the confession electrical input that exchanges scale generation module and signal mixed circuit simultaneously and is its power supply.The input end of current signal Acquisition Circuit is connected with the output terminal of solenoid, and current signal Acquisition Circuit adopts the little mutual inductor of secondary to carry out the collection of current signal, obtains analog current signal waiting for transmission (being designated as electric signal I1).Direct current scale generation module with exchange scale generation module and generate respectively a fixing direct current scale signal (being designated as electric signal I2) and exchange scale signal (being designated as electric signal I3).In the electronic current mutual inductor of this employing Optical Fiber Transmission simulating signal, direct current scale signal generation module adopts direct current pio chip to realize, as canonical reference source chip REF5020, exchange scale signal generation module and adopt the sine-wave generator of arbitrary form to realize.
Direct current scale generation module is together admitted in signal mixed circuit with the analog current signal waiting for transmission that the direct current scale signal, interchange scale signal and the current signal Acquisition Circuit that exchange the generation of scale generation module collect.Signal mixed circuit adopts integrated operational amplifier to realize, direct current scale signal, interchange scale signal and analog current signal waiting for transmission are superposeed, stack forms and mixes electric signal (being designated as electric signal I4), then will mix electric signal (electric signal I4) and deliver to electric signal switching emission module.
Electric signal switching emission module comprises: electro-optical conversion circuit and light emission port, light emission port is connected with optical fiber 3.The signal output part of signal mixed circuit is connected with the signal input part of electro-optical conversion circuit, and mixing electric signal is sent in electro-optical conversion circuit.In electro-optical conversion circuit, comprise visible ray luminotron and drive the peripheral circuit of visible ray luminotron work.After mixing electric signal (electric signal I4) enters electro-optical conversion circuit, drive visible ray luminotron luminous, realize the conversion of electric signal-light signal, be converted to light signal (being designated as light signal S1).The light signal that electrooptic conversion module conversion forms, by light emission port, carries out long-distance transmissions by the optical fiber 3 being connected with light emission port.The voltage output end of above-mentioned stabilized voltage supply is connected with the voltage input end of electrooptic conversion module simultaneously and is its power supply.
As shown in Figure 3, the light signal (light signal S1) being sent by light transmitting terminal 1 is delivered to optical receiving end 2 after optical fiber 3 transmission, and the light signal (being designated as light signal S1 ') after transmission receives modular converter reception by the light signal in optical receiving end 2 and obtains.Light signal receives modular converter and comprises light-receiving port and photoelectric switching circuit.The light signal receiving is delivered to photoelectric switching circuit by light-receiving port, in photoelectric switching circuit, complete the conversion of light signal-electric signal, be converted to the mixing electric signal (being designated as electric signal I4 ') of optical receiving end 2, photoelectric switching circuit adopts photoelectric tube (as photodiode or phototriode) to realize the conversion of light signal-electric signal.Photoelectric switching circuit is sent the mixing electric signal being converted to (electric signal I4 ') into signal conditioning circuit.
Signal conditioning circuit comprises: demultiplexing circuit, signal tracking circuit and gain control circuit.The output terminal of photoelectric switching circuit is connected with the input end of demultiplexing circuit, and the mixing electric signal being converted to (electric signal I4 ') is sent in signal separation module.Signal separation module receives mixes electric signal (electric signal I4 ') afterwards, this mixing electric signal (electric signal I4 ') is separated, separate and obtain three analog current signals: analog current signal (being designated as electric signal I1 '), direct current scale signal (being designated as electric signal I2 ') and exchange scale signal (being designated as electric signal I3 ').Demultiplexing circuit can be realized by active band-pass filter.
As mentioned above, in transmitting procedure, there is decay to a certain degree in the light signal (light signal S1) that light transmitting terminal 1 generates, decay to the light signal (light signal S1 ') that optical receiving end 2 receives, the reason of decay comprises the many aspects such as the efficiency of the luminescence efficiency of light source, the joints of optical fibre, optical fiber attenuation, photoelectric detector.Therefore, the mixing electric signal (electric signal I4 ') that optical receiving end 2 internal conversions of comparing obtain, obtain in 1 internal conversion of light transmitting terminal the light signal (light signal S1) that generates with light transmitting terminal 1 after transmission of mixing electric signal (electric signal I4 ') there is the decay of same degree.Further, analog current signal waiting for transmission (electric signal I1), the direct current scale signal (electric signal I2) that obtains or generate in light transmitting terminal 1 and exchange scale signal (electric signal I3) and also occurred the decay of same degree after transmission, is separated analog current signal (electric signal I1 '), the direct current scale signal (electric signal I2 ') obtaining and is exchanged scale signal (electric signal I3 ') by demultiplexing circuit.
Mix electric signal (electric signal I4 ') at process demultiplexing circuit after separating, the analog current signal (electric signal I1 ') obtaining is admitted to signal tracking circuit, and the direct current scale signal (electric signal I2 ') that demultiplexing circuit obtains separation according to actual needs and/or interchange scale signal (electric signal I3 ') are admitted to gain control circuit.Because the direct current scale signal (electric signal I2) of light transmitting terminal 1 interior generation is known with the parameter that exchanges scale signal (electric signal I3), therefore the MCU in gain control circuit by the direct current scale signal to before and after decay with exchange scale signal and detect and can calculate direct current scale signal and exchange the attenuation coefficient of scale signal in transmitting procedure.From the above, analog current signal (electric signal I1) has occurred and decay straight, that exchange scale signal same degree in transmitting procedure, can compensate analog current signal (electric signal I1 ') by attenuation degree straight, that exchange scale signal, make it to revert to analog current signal waiting for transmission (being designated as electric signal I1).Gain control circuit calculates directly, exchanges the attenuation coefficient of scale signal in transmitting procedure according to the radiometer straight, that exchange the amplitude of scale signal before and after transmission, and then gain control circuit is delivered to as gain control signal the attenuation coefficient straight, that exchange scale signal calculating in signal tracking circuit.The gain control signal that signal tracking circuit is sent into according to gain control circuit, the analog current signal of having been sent into by demultiplexing circuit (electric signal I1 ') is compensated, make it to revert to the analog current signal waiting for transmission (electric signal I1) that current signal Acquisition Circuit collects, in the electronic current mutual inductor of this employing Optical Fiber Transmission simulating signal, signal tracking circuit adopts four-quadrant analog multiplier, to realize tracking and the gain-adjusted to analog current signal (electric signal I1 '), signal tracking circuit also can be realized by gain adjustable amplifier.The output terminal of signal tracking circuit is connected with the signal input part of standard signal output circuit, signal tracking circuit is sent the analog current signal (electric signal I1) obtaining after compensation into standard signal output circuit, the analog current signal (electric signal I1) compensation being obtained by standard signal output circuit is nursed one's health again, can be according to on-the-spot actual needs, analog current signal (electric signal I1) conditioning, for meeting analog current signal or the analog voltage signal of on-the-spot actual demand, is then exported by standard signal output circuit.
The above, be only preferred embodiment of the present invention, is not the restriction of the present invention being made to other form, and any those skilled in the art may utilize the technology contents of above-mentioned announcement to be changed or be modified as the equivalent embodiment of equivalent variations.But every technical solution of the present invention content that do not depart from, any simple modification, equivalent variations and the remodeling above embodiment done according to technical spirit of the present invention, still belong to the protection domain of technical solution of the present invention.