CN103575972B - The inner current in resistance property measuring system of electric transmission line isolator - Google Patents
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Abstract
The invention discloses the inner current in resistance property measuring system of a kind of electric transmission line isolator, it comprises: current transformer detects the total current of insulator ABC three-phase; Current sensor detects the surperficial Leakage Current of insulator ABC three-phase; First signal modulate circuit, the full current signal that current transformer is detected is nursed one's health; Secondary signal modulate circuit, the surperficial Leakage Current signal that current sensor is detected is nursed one's health; Synchronized sampling unit, it is connected respectively with described first signal modulate circuit and secondary signal modulate circuit, and full current signal and the surperficial Leakage Current signal of synchronous acquisition process signal condition also carries out AD conversion output; One MCU, it is connected with described synchronized sampling unit, and the total current It of described MCU synchronous acquisition insulator and surperficial Leakage Current Il obtain the inner current in resistance property Iin of insulator according to total current It and surperficial Leakage Current Il.
Description
Technical field
The present invention relates to a kind of current measurement system, relate in particular to a kind of electric transmission line isolator current measurementSystem.
Background technology
Composite insulator is because its excellent resistant is dodged performance and is applied to more and more widely in transmission line of electricity,Particularly UHV transmission line is to adopt composite insulator at present substantially. Fracture and brittle failure are compoundOne of main forms of insulator breakdown. Because insulator did not have before generation fracture and brittle failureThe means of effect detect, once insulator ruptures, will cause circuit catastrophic discontinuityfailure, have reducedThe reliability of whole system. Therefore effective monitoring method of studying insulator fracture and brittle failure is insulator inspectionSurvey one of the most promising problem.
Because insulator long-term work is under stable voltage, its inner current in resistance property can Efficient Characterization insulationThe inner deterioration state of son, therefore the inside current in resistance property of composite insulator can more efficiently characterize insulatorState of insulation. The equivalent circuit of composite insulator can abbreviation be capacitance-resistance parallel connection, as shown in Figure 1, and IgFor insulator capacity current, I is that insulator current in resistance property (comprises insulator internal leakage electric current I in and exhaustedEdge sub-surface Leakage Current Il), Rin is the inner equivalent resistance of insulator, Rl is that insulator surface is revealed electricityResistance, Cg is insulator equivalent capacity, the total current that It is insulator. In the time that the inner appearance of insulator is deteriorated,Can there is significant change in insulator current in resistance property, when environmental change simultaneously, and table while becoming large, rainy as humidityFace Leakage Current changes also can cause the variation of insulator current in resistance property, therefore will monitor insulator inside badChange state must eliminate surperficial resistive Leakage Current from current in resistance property composition. And use now moreInsulator monitoring method is insulator surface Leakage Current measuring method.
Publication number is CN102654527A, and open day is on September 5th, 2012, and name is called " insulatorCurrent in resistance property peak-detector circuit " Chinese patent literature and publication number be CN102654525A, public affairsOpening day is on September 5th, 2012, and name is called the Chinese patent literary composition of " insulator current in resistance property split circuit "Offer the separation method that discloses a kind of insulator current in resistance property, but in fact said method only just separatesCapacity current, just insulator internal leakage electric current and the insulator surface Leakage Current sum of measurement.
Summary of the invention
The object of the present invention is to provide the inner current in resistance property measuring system of a kind of electric transmission line isolator, itsThe inside current in resistance property of energy Measurement accuracy insulator.
To achieve these goals, the present invention proposes the inner current in resistance property of a kind of electric transmission line isolator surveysAmount system, it comprises:
Three current transformers, it detects respectively the total current of insulator ABC three-phase;
Three current sensors, it detects respectively the surperficial Leakage Current of insulator ABC three-phase;
First signal modulate circuit, it is connected with described three current transformers, to three current transformersThe full current signal detecting is nursed one's health;
Secondary signal modulate circuit, it is connected with described three current sensors, to three current sensorsThe surperficial Leakage Current signal detecting is nursed one's health;
Synchronized sampling unit, it connects respectively with described first signal modulate circuit and secondary signal modulate circuitConnect, full current signal and the surperficial Leakage Current signal of synchronous acquisition process signal condition also carries out AD conversionOutput;
One MCU, it is connected with described synchronized sampling unit, and it is complete that described MCU characterizes according to full current signalElectric current It＝K1(ω t) and the surperficial Leakage Current of surperficial Leakage Current characterization for cosSampled value determine the amplitude K of total current and surperficial Leakage Current1、K2, andThe phase difference of total current and the surperficial Leakage Current corresponding with itAnd angular frequency; Described MCU comprises:Multiplication module, the total current I that it characterizes full current signalt＝K1Cos (ω t) with surperficial Leakage CurrentThe surperficial Leakage Current of characterizationAfter doing multiplication, obtain resultLow pass filter, its with described in take advantage ofMusical instruments used in a Buddhist or Taoist mass connects, and receives the result of multiplier output and filtering high fdrequency component C from result1, obtain low frequency divisionAmount C2; Described MCU is according to low frequency component C2Amplitude K with surperficial Leakage Current2Obtain the inner resistance of insulatorProperty electric current IinAmplitude 2C2/K2-K2, then export the inner current in resistance property of edge
Preferably, in the inner current in resistance property measuring system of electric transmission line isolator of the present invention, instituteStating current transformer is zero-flux current transformer.
Further, in the inner current in resistance property measuring system of electric transmission line isolator of the present invention,Described first signal modulate circuit comprises amplifying circuit and holds resistance filter circuit.
Further, in the inner current in resistance property measuring system of electric transmission line isolator of the present invention,Described first signal modulate circuit comprises: Transient Suppression Diode, and it is in parallel with voltage twin zener dioder,Also just defeated with the first operational amplifier of one end that described Transient Suppression Diode receives described full current signalEnter end connect, the other end ground connection of described Transient Suppression Diode, this earth terminal also with one of the first resistanceEnd connects, and the other end of the first resistance is connected with the negative input end of the first operational amplifier, the first resistanceThe other end is connected with the output of the first operational amplifier after being also connected in series the second resistance, the first operational amplifierOutput by the 3rd resistance output the full current signal through signal condition.
In above-mentioned first signal modulate circuit, Transient Suppression Diode plays the work of transition and surge protectionWith; Voltage twin zener dioder is limited in input voltage in one fixed range; The work of the first operational amplifierWith the isolation transmission that is settling signal; The first resistance, the second resistance and the 3rd resistance form in-phase amplifier.
It is the operational amplifier of OP27 that above-mentioned the first operational amplifier can adopt model, its power supply termination+ 5VDC and-5VDC. OP27 precision operational-amplifier have low maladjustment voltage, drift, at a high speed, low noiseCharacteristic.
Further, in the inner current in resistance property measuring system of electric transmission line isolator of the present invention,Described secondary signal modulate circuit comprises: the first sampling resistor of series connection and the second sampling resistor, describedOne end of one sampling resistor receives described surperficial Leakage Current signal, and the first sampling resistor receiving surface is revealedOne end of current signal is also connected with the first sampling output circuit, and this first sampling output circuit output in a small amountJourney sampled signal, the other end of described the first sampling resistor is connected with one end of the second sampling resistor, and secondThe other end ground connection of sampling resistor, the second sampling output circuit is connected in the first sampling resistor and the second samplingOn the connecting line of resistance, this second sampling output circuit output wide range sampled signal.
Further, in the inner current in resistance property measuring system of electric transmission line isolator of the present invention,Described the first sampling output circuit comprises: the second operational amplifier, its positive input terminal connects by the 4th resistanceConnect one end of described the first sampling resistor, the positive input terminal of described the second operational amplifier is also by the one or twoUtmost point pipe ground connection, the positive input terminal of the second operational amplifier also connects the second operational amplifier by the 5th resistanceOutput, the negative input termination bias voltage of the second operational amplifier, simultaneously by the first capacity earth,The output of described the second operational amplifier is exported described small-range sampled signal; Described the second sampling outputCircuit comprises: the 3rd operational amplifier, its positive input terminal connects described the second sampling resistor by the 6th resistanceOne end, the positive input terminal of the 3rd operational amplifier is also by the second diode ground connection, described the 3rd computingThe positive input terminal of amplifier also connects the output of the 3rd operational amplifier, the described the 3rd by the 7th resistanceThe negative input termination bias voltage of operational amplifier, simultaneously by the second capacity earth, described the 3rd computingThe output of amplifier is exported described wide range sampled signal.
In above-mentioned secondary signal modulate circuit, select suitable sampling resistor, can be on range and essenceOn degree, meet the demands simultaneously. Measurement category is small-range and two intervals of wide range, when surperficial Leakage CurrentThe current value of signal is in the time that small-range is interval, and system is measured the first sampling resistor and the second sampling resistor automaticallyThe output voltage of series connection; When the current value of described surperficial Leakage Current signal is in the time that wide range is interval, systemAutomatically measure the output voltage on sampling resistor Rb.
Further, in the inner current in resistance property measuring system of electric transmission line isolator of the present invention,Described synchronized sampling unit comprises multi-channel synchronous AD converter.
Further, in the inner current in resistance property measuring system of above-mentioned electric transmission line isolator, described manyChannel Synchronous AD converter model is AD7606-6. AD7606-6 is that a 16,6 Channel Synchronous adoptSample AD translation data acquisition system. Need to be appreciated that, those skilled in that art also can select otherSuitable multi-channel synchronous adopts unit, and AD7606-6 multi-channel synchronous AD converter should not served as thisThe restriction of technical scheme.
Further, in the inner current in resistance property measuring system of electric transmission line isolator of the present invention,The model of described MCU is LPC2292. Need to be appreciated that, those skilled in that art also can selectThe MCU that other are suitable, the MCU that for example chip model is LPC2294, therefore model is LPC2292MCU should not served as the restriction to the technical program.
The inner current in resistance property measuring system of electric transmission line isolator provided by the invention, it can measure insulatorInner current in resistance property, has solved the problem that insulator current in resistance property is difficult to obtain, and is the deteriorated journey of insulatorDegree is judged provides data supporting, for fracture and the brittle failure of insulator provide effective monitoring, thereby effectively avoidsCircuit catastrophic discontinuityfailure, the reliability of raising whole system.
Brief description of the drawings
Fig. 1 is the insulator equivalent circuit diagram in transmission line of electricity.
Fig. 2 is the insulator current vector figure in transmission line of electricity.
Fig. 3 is that the inner current in resistance property measuring system of electric transmission line isolator of the present invention is implemented in oneStructural representation block diagram under mode.
Fig. 4 is that the inner current in resistance property measuring system of electric transmission line isolator of the present invention is implemented in oneThe circuit diagram of the first signal modulate circuit under mode.
Fig. 5 is that the inner current in resistance property measuring system of electric transmission line isolator of the present invention is implemented in oneThe circuit diagram of the secondary signal modulate circuit under mode.
Fig. 6 is that the inner current in resistance property measuring system of electric transmission line isolator of the present invention is implemented in oneThe circuit diagram of the synchronized sampling unit under mode.
Fig. 7 is that the inner current in resistance property measuring system of electric transmission line isolator of the present invention is implemented in oneThe circuit diagram of MCU under mode.
Fig. 8 is that the inner current in resistance property measuring system of electric transmission line isolator of the present invention is implemented in onePart implementing procedure figure under mode.
Detailed description of the invention
Below in conjunction with Figure of description and specific embodiment to electric transmission line isolator of the present inventionInner current in resistance property measuring system is made further explanation and explanation.
As shown in Figure 1, the equivalent circuit of composite insulator can abbreviation be the inner equivalent resistance Rin of insulatorIn parallel with insulator surface leak resistance Rl. Ig is insulator capacity current, and I is insulator current in resistance property,It comprises the inner current in resistance property Iin of insulator and insulator surface Leakage Current Il, and Cg is insulator equivalent electricHold. It is the total current of insulator. In the time that the inner appearance of insulator is deteriorated, insulator current in resistance property I can send outRaw significant change, when environmental change simultaneously, while becoming large or rainy as humidity, the change of surperficial Leakage Current IlChange the variation that also can cause insulator current in resistance property I. Therefore will monitor the inner current in resistance property of insulator must be fromIn current in resistance property composition, eliminate surperficial Leakage Current.
Can obtain the inner current in resistance property Iin of insulator, surperficial Leakage Current according to the equivalent circuit shown in Fig. 1The vectogram of Il, total current It, capacity current Ig as shown in Figure 2. As shown in Figure 2,
According to formula 1, can: the total current It of synchronous acquisition insulator and surperficial Leakage Current Il, utilizePhasemeter between It and Il calculates capacity current Ig and current in resistance property I, the inner current in resistance property of insulatorFor Iin=I-Il. If It＝K1cos(ωt)，?
Then filtering high fdrequency component, can obtain C2。
OrderCan obtain
Again by with poor eliminate indigestion formula can be by ItBe decomposed into
C in formula 23For insulator current in resistance property, C4For insulator capacity current, contrast 2 and Il'sExpression formula can obtain the inner current in resistance property of insulator and can be expressed as
Based on above-mentioned principle analysis, the technical program provides a kind of electric transmission line isolator inner resistive electricityFlow measuring system. Fig. 3 has shown the inner current in resistance property of electric transmission line isolator of the present invention Department of SurveyThe structural representation block diagram of system under a kind of embodiment. As shown in Figure 3, at the transmission line of electricity of the present embodimentThe inner current in resistance property measuring system of insulator comprises: three zero-flux current transformers, it detects respectively absolutelyThe total current It of edge ABC three-phase; Three surperficial Leakage Current sensors, it detects respectively insulatorThe surperficial Leakage Current Il of ABC three-phase; First signal modulate circuit, itself and three zero flux current mutual inductancesDevice connects, and the full current signal that zero-flux current transformer is detected is nursed one's health; Secondary signal conditioningCircuit, it is connected with three surperficial Leakage Current sensors, and effects on surface Leakage Current sensor detectsSurface Leakage Current signal is nursed one's health; Synchronized sampling unit, itself and first signal modulate circuit and secondSignal conditioning circuit connects respectively, and synchronous acquisition is revealed electricity through full current signal and the surface of signal conditionStream signal also carries out AD conversion output; MCU is connected with synchronized sampling unit, and MCU is according to full current signalThe total current I characterizingt＝K1(ω t) and the surperficial Leakage Current of surperficial Leakage Current characterization for cosSampled value determine the amplitude K of total current and surperficial Leakage Current1、K2, andThe phase difference of total current and the surperficial Leakage Current corresponding with itAnd angular frequency; This MCU comprises: take advantage ofMusical instruments used in a Buddhist or Taoist mass module, the total current I that it characterizes full current signalt＝K1(ω t) believes with surperficial Leakage Current cosNumber characterize surperficial Leakage CurrentAfter doing multiplication, obtain resultLow pass filter, its with described in take advantage ofMusical instruments used in a Buddhist or Taoist mass connects, and receives the result of multiplier output and filtering high fdrequency component C from result1, obtain low frequency divisionAmount C2; Described MCU is according to low frequency component C2Amplitude K with surperficial Leakage Current2Obtain the inner resistance of insulatorProperty electric current IinAmplitude 2C2/K2-K2, then export the inner current in resistance property of edge
Fig. 4 has shown the circuit diagram of a kind of first signal modulate circuit adopting in the technical program. As figureShown in 4, this first signal modulate circuit comprises: Transient Suppression Diode D204 (model TSMB6.8CA),It is in parallel with voltage twin zener dioder D205 (model GBLC03), one of Transient Suppression Diode D204Termination receives current signal, the positive input terminal of one end of this reception full current signal and operational amplifier U204Connect the other end ground connection of Transient Suppression Diode D204, the earth terminal of Transient Suppression Diode D204Be connected the other end of the first resistance R 210 and operational amplifier U204 with one end of the first resistance R 210Negative input end connect, the other end of the first resistance R 210 is by the second resistance R 211 and operational amplifierThe output of U204 connects, and the output of operational amplifier U204 is by the 3rd resistance R 212 output processesThe full current signal of signal condition. In such an embodiment, voltage twin zener dioder D205 can be by inputLimiting voltage is in 3V; The first resistance R 210 resistance position 10k Ω, the second resistance R 211 resistances are 10kΩ, the 3rd resistance R 212 resistances are 1k Ω, and these three resistance have formed in-phase amplifier, multiplication factorIt is 2 times. In the present embodiment, operational amplifier U204 can be the operational amplifier of model OP27,Its power supply termination+5VDC and-5VDC.
Fig. 5 has shown the circuit diagram of a kind of secondary signal modulate circuit adopting in the technical program. As figureShown in 5, secondary signal modulate circuit comprises: the first sampling resistor Ra of series connection and the second sampling resistor Rb,Wherein one end receiving surface Leakage Current signal of the first sampling resistor Ra, this receiving surface Leakage Current letterNumber one end be also connected with the first sampling output circuit, the first sampling output circuit output small-range sampling letterNumber Vout1, the other end of the first sampling resistor Ra is connected with the second sampling resistor Rb, the second sampling electricityThe other end ground connection of resistance Rb, the second sampling output circuit is connected in the first sampling resistor R and the second sampling electricityOn connecting line between resistance Rb, the second sampling output circuit output wide range sampled signal Vout2. Wherein,In the first sampling output circuit, operational amplifier U1A is single supply type, its 4th pin ground connection, theEight pins meet power supply VCC, and its positive input terminal connects one end of the first sampling resistor Ra by the 4th resistance R 1,The positive input terminal of operational amplifier U1A is also by the first diode D1 ground connection, and operational amplifier U1A justInput also connects the output of operational amplifier U1A by the 5th resistance R 2, operational amplifier U1A's is negativeInput termination bias voltage Vref, the negative input end of operational amplifier U1A also connects by the first capacitor C 1Ground, the output output small-range sampled signal Vout1 of operational amplifier U1A; In the second sampling outputIn circuit, operational amplifier U2A is single supply type, its 4th pin ground connection, and the 8th pin meets power supply VCC,Its positive input terminal meets one end of the second sampling resistor Rb, operational amplifier U2A's by the 6th resistance R 3Positive input terminal is also by the second diode D2 ground connection, and the positive input terminal of operational amplifier U2A is also by the 7thResistance R 4 connects the output of operational amplifier U2A, the negative input termination bias voltage of operational amplifier U2AVref, the negative input end of operational amplifier U2A also passes through the second capacitor C 2 ground connection, operational amplifier U2AOutput output wide range sampled signal Vout2. In above-mentioned secondary signal modulate circuit, select to closeSuitable sampling resistor can meet the demands on range He in precision simultaneously. Measurement category is small-range (exampleAs, 10uA～2.4mA) and two intervals of wide range (for example, 2mA～100mA), when electricity is revealed on surfaceThe current value of stream signal is in the time that small-range (10uA～2.4mA) is interval, and system is measured the first sampling electricity automaticallyThe output voltage of resistance Ra and the second sampling resistor Rb series connection; When the current value of surperficial Leakage Current signal existsWhen wide range (2mA～100mA) is interval, system is measured the output voltage on sampling resistor Rb automatically. ByAll generally in small-range (10uA～2.4mA) interval in the current value of surperficial Leakage Current signal,When reality realizes, the present embodiment, to small-range sampled signal Vout1 sampling 1s, is referred to as to adopt in advanceSample, then calculates sampled value, if really there is Vout1 < 1.2V, shows surperficial Leakage Current letterNumber current value really in small-range (10uA～2.4mA) interval, when sampling that so just can be in accordance with regulationsBetween sample small-range sampled signal Vout1 and then analytical calculation. Otherwise, if find small-range samplingSignal Vout1 > 1.2V, just think the current value that shows surperficial Leakage Current signal wide range (2mA～100mA) interval, wide range sampled signal Vout2 so just can sample in the sampling time in accordance with regulations. LittleRange sampled signal Vout1 and wide range sampled signal Vout2 access an analog switch simultaneously, by journeyThe a certain path of order control gating. Operational amplifier U1A and operational amplifier U2A all can adopt model to beThe operational amplifier of LMV358.
Fig. 6 has shown the circuit diagram of a kind of synchronized sampling unit adopting in the technical program. As Fig. 6 instituteShow, in figure, 3,4, No. 5 pins are over-sampling selecting side, select respectively with the corresponding over-sampling of MCUOutput pin is connected, and carries out over-sampling selection; No. 6 pins are 6 Channel Synchronous AD converter (modelsAD7606-6) interface mode is selected, and selects parallel output mode while connecing low level, connects high level and selects stringLine output mode, connects low level and selects parallel mode in the present embodiment; No. 7 pins are hang-up pin, byWhether LPC2292 controls AD7606-6 and hangs up, Low level effective; No. 8 pins are that RANGE selects inputEnd, by resistance R 500 (resistance 100K Ω) ground connection, simultaneously with the AD_RangeSel of LPC2292Pin is connected, and in the time that RANGE input is low level, sample range is ± 5V, when RANGE inputDuring for high level, sample range is ± 10V; No. 23 pins are VDRIE pin, adopt 3.3V; 9,10Number pin is first three road, Hou San road sample frequency input pin; No. 11 pin is RST pin, works as AD7606-6Before normal work, need to carry out reset operation to it, be controlled by LPC2292; 12,13 pin respectivelyRead signal input pin and the chip selection signal input pin of AD7606-6 while controlling data for reading; 14Number pin is interrupt output pin, has sampled at every turn, and AD7606-6 will export interrupt signal notice LPC2292Sampling finishes; No. 15 pin is FirstData mark pin, plays mark effect for serial output mode;44,45 pin are respectively first three road, Hou San road reference capacitance pin, connect 46 after connecing 10uF capacitor C 504Number pin AGND, ensures reference voltage waveform stabilization in sampling process.
Fig. 7 has shown the circuit diagram of a kind of MCU adopting in the technical program. This MUC has adopted modelFor the chip of LPC2292. As shown in Figure 7, J40, R40 (4k7 Ω), R41 (1k Ω), R42 (100kΩ), R45 (1k Ω) and C40 (10uF) jointly form the program download interface of LPC2292 and areSystem electrify restoration circuit; 42 and 49 pin are serial communication port, main and 61850 stipulations modular convertersCommunication; 33 pin and 99 pin are triggering signal input port, in the time having triggering signal, are opened by LPC2292Moving data sampling program; 59,61,68 and 12 pin form SPI COM1, and LPC2292 mainly passes throughSPI port is set threshold values to the output of DA converter; 100 pin are that AD changes complete signal, when it is low electricityAt ordinary times, show AD EOC, LPC2292 according to the rules sequential reads AD conversion value; C43 (30pF),When C44 (30pF), JT40 (18.432MHz) and R45 (10M Ω) form the vibration of LPC2292Clock, for system provides stabilizing clock; Exi_DATA0-15 is system data line; AD_RangeSel,AD_RST, AD_nSTBY, AD_OverSmpl0-2 and AD_FstData are situated between in AD7606-6 partContinue; Xi_ADD0-23 is system address line; Exi_nRD, Exi_nWR are respectively read-write control signal;CS_SRAM and AD_CS are respectively the select lines of memory and AD converter.
Fig. 8 is that the inner current in resistance property measuring system of electric transmission line isolator of the present invention is implemented in onePart implementing procedure figure under mode. As shown in Figure 8, the transmission line of electricity described in employing the technical program is exhaustedThe inner current in resistance property measuring system of edge is according to the following step, and the inside that can accurately record insulator is resistiveElectric current:
(1) adopt three zero-flux current transformers to detect respectively the total current of insulator ABC three-phase; AdoptDetect respectively the surperficial Leakage Current of insulator ABC three-phase with three surperficial Leakage Current sensors;
(2) full current signal that adopts first signal modulate circuit to detect zero-flux current transformer is enteredRow amplifies and holds and hinder filtering; Adopt the also effects on surface Leakage Current sensor inspection of secondary signal modulate circuit simultaneouslyThe surperficial Leakage Current signal measuring is nursed one's health;
(3) the total current I of employing synchronized sampling device synchronous acquisition insulatortWith surperficial Leakage Current IlWherein surperficial Leakage CurrentTotal currentIn formulaFor entirelyThe phase difference of electric current and the surperficial Leakage Current corresponding with it, K1And K2Be respectively total current and surface is let outThe amplitude of revealing electric current, ω represents angular frequency;
(4) according to surperficial Leakage Current IlWith total current ItSampled value determine K1、K2, ω and
(5) adopt multiplier effects on surface Leakage Current IlWith total current ItDo multiplication, obtainAdopt wave digital lowpass filter filteringHigh fdrequency component C in multiplication result1, obtain low frequency component C2；
According to the K obtaining in above-mentioned steps2And C2Obtain the inner current in resistance property I of insulatorinAmplitude2C2/K2-K2；
Obtain the inner current in resistance property of insulator
Be noted that above enumerate only for specific embodiments of the invention, obviously the invention is not restricted toAbove embodiment has many similar variations thereupon. If those skilled in the art is from public affairs of the present inventionAll distortion that the content of opening directly derives or associates, all should belong to protection scope of the present invention.
Claims (9)
1. the inner current in resistance property measuring system of electric transmission line isolator, is characterized in that, comprising:
Three current transformers, it detects respectively the total current of insulator ABC three-phase;
Three current sensors, it detects respectively the surperficial Leakage Current of insulator ABC three-phase;
First signal modulate circuit, it is connected with described three current transformers, to three Current Mutual InductancesThe full current signal that device detects is nursed one's health;
Secondary signal modulate circuit, it is connected with described three current sensors, to three current sensesThe surperficial Leakage Current signal that device detects is nursed one's health;
Synchronized sampling unit, itself and described first signal modulate circuit and secondary signal modulate circuit are respectivelyConnect, full current signal and the surperficial Leakage Current signal of synchronous acquisition process signal condition also carries outAD changes output;
One MCU, it is connected with described synchronized sampling unit, and described MCU characterizes according to full current signalTotal current It＝K1(ω t) and the surperficial Leakage Current of surperficial Leakage Current characterization for cosSampled value determine the amplitude K of total current and surperficial Leakage Current1、K2, withAnd the phase difference of total current and the surperficial Leakage Current corresponding with itAnd angular frequency; Described MCUComprise: multiplication module, the total current I that it characterizes full current signalt＝K1(ω is t) with surperficial for cosThe surperficial Leakage Current of Leakage Current characterizationAfter doing multiplication, tiedReallyWherein,Low pass filter, itself and described multiplicationDevice connects, and receives the result of multiplier output and filtering high fdrequency component C from result1, obtain low frequency divisionAmount C2; Described MCU is according to low frequency component C2Amplitude K with surperficial Leakage Current2Obtain in insulatorThe current in resistance property I of portioninAmplitude 2C2/K2-K2, then export the inner current in resistance property of edge
2. the inner current in resistance property measuring system of electric transmission line isolator as claimed in claim 1, its feature existsIn, described current transformer is zero-flux current transformer.
3. the inner current in resistance property measuring system of electric transmission line isolator as claimed in claim 1, its feature existsIn, described first signal modulate circuit comprises amplifying circuit and holds resistance filter circuit.
4. the inner current in resistance property measuring system of electric transmission line isolator as claimed in claim 1, its feature existsIn, described first signal modulate circuit comprises: Transient Suppression Diode (D204), itself and voltage press downDiode processed (D205) parallel connection, described Transient Suppression Diode (D204) receives described total current letterNumber one end be also connected with the positive input terminal of the first operational amplifier (U204), described transient state suppresses twoThe other end ground connection of utmost point pipe (D204), this earth terminal is also connected with one end of the first resistance (R210),The other end of the first resistance (R210) is connected with the negative input end of the first operational amplifier (U204),The other end of the first resistance (R210) is also connected in series the second resistance (R211) afterwards and the first operational amplifier(U204) output connects, and the output of the first operational amplifier (U204) is by the 3rd resistance(R212) output is through the full current signal of signal condition.
5. the inner current in resistance property measuring system of electric transmission line isolator as claimed in claim 1, its feature existsIn, described secondary signal modulate circuit comprises the first sampling resistor (Ra) and the second sampling electricity of series connectionResistance (Rb), one end of described the first sampling resistor (Ra) receives described surperficial Leakage Current signal,One end of the first sampling resistor (Ra) receiving surface Leakage Current signal also with the first sampling output circuitConnect this first sampling output circuit output small-range sampled signal (Vout1), described the first samplingThe other end of resistance (Ra) is connected with one end of the second sampling resistor (Rb), the second sampling resistor (Rb)Other end ground connection, second sampling output circuit be connected in the first sampling resistor (Ra) and second sampleOn the connecting line of resistance (Rb), this second sampling output circuit output wide range sampled signal (Vout2).
6. the inner current in resistance property measuring system of electric transmission line isolator as claimed in claim 5, its feature existsIn:
Described the first sampling output circuit comprises: the second operational amplifier (U1A), its positive input terminal is logicalCross one end that the 4th resistance (R1) connects described the first sampling resistor (Ra), described the second computing is putThe positive input terminal of large device (U1A) also passes through the first diode (D1) ground connection, the second operational amplifier(U1A) positive input terminal also passes through the 5th resistance (R2) connection the second operational amplifier (U1A)Output, the negative input termination bias voltage Vref of the second operational amplifier (U1A) passes through simultaneouslyThe first electric capacity (C1) ground connection, the output output of described the second operational amplifier (U1A) is described littleRange sampled signal Vout1;
Described the second sampling output circuit comprises: the 3rd operational amplifier (U2A), its positive input terminal is logicalCross one end that the 6th resistance (R3) connects described the second sampling resistor (Rb), the 3rd operational amplifier (U2A)Positive input terminal also by the second diode (D2) ground connection, described the 3rd operational amplifier (U2A)Positive input terminal also connect the output of the 3rd operational amplifier (U2A) by the 7th resistance (R4),The negative input termination bias voltage Vref of described the 3rd operational amplifier (U2A), simultaneously by secondElectric capacity (C2) ground connection, the output of described the 3rd operational amplifier (U2A) is exported described wide rangeSampled signal Vout2.
7. the inner current in resistance property measuring system of electric transmission line isolator as claimed in claim 1, its feature existsIn, described synchronized sampling unit comprises multi-channel synchronous AD converter.
8. the inner current in resistance property measuring system of electric transmission line isolator as claimed in claim 7, its feature existsIn, described multi-channel synchronous AD converter model is AD7606-6.
9. the inner current in resistance property measuring system of electric transmission line isolator as claimed in claim 1, its feature existsIn, the model of described MCU is LPC2292.
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| CN103983840A (en) * | 2014-06-11 | 2014-08-13 | 国家电网公司 | Device for monitoring leakage and corona pulse current of alternating current insulator on line and online monitoring method using device |
| CN105426649B (en) * | 2014-09-18 | 2018-03-27 | 国家电网公司 | A kind of separation computational methods of Leakage Current |
| CN106771869A (en) * | 2016-12-21 | 2017-05-31 | 哈尔滨理工大学 | Long range power cable insulation on-line monitoring method based on current in resistance property partition method |
| CN112305347B (en) * | 2020-10-20 | 2022-06-10 | 云南电网有限责任公司电力科学研究院 | MOA bypass type sampling total current measuring method |
| CN114814500B (en) * | 2022-06-28 | 2022-09-23 | 宁波均胜新能源研究院有限公司 | Alternating current insulation detection method and device |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4492918A (en) * | 1982-08-26 | 1985-01-08 | Terra Technology Corp. | High voltage power line phase angle and current measuring instrument |
| CN102043084A (en) * | 2010-12-06 | 2011-05-04 | 上海思盛信息科技事务所 | Method for detecting resistive current of lightning arrester |
| CN102654527A (en) * | 2011-03-03 | 2012-09-05 | 上海诚佳电子科技有限公司 | Insulator resistive current peak detection circuit |
| CN202794410U (en) * | 2012-07-11 | 2013-03-13 | 成都措普科技有限公司 | Monitoring system for leakage current of insulator |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| US6714000B2 (en) * | 1999-06-14 | 2004-03-30 | Genscape, Inc. | Method for monitoring power and current flow |
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4492918A (en) * | 1982-08-26 | 1985-01-08 | Terra Technology Corp. | High voltage power line phase angle and current measuring instrument |
| CN102043084A (en) * | 2010-12-06 | 2011-05-04 | 上海思盛信息科技事务所 | Method for detecting resistive current of lightning arrester |
| CN102654527A (en) * | 2011-03-03 | 2012-09-05 | 上海诚佳电子科技有限公司 | Insulator resistive current peak detection circuit |
| CN202794410U (en) * | 2012-07-11 | 2013-03-13 | 成都措普科技有限公司 | Monitoring system for leakage current of insulator |
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