On-line overvoltage monitor based on the dual time base Sampling techniques
Technical field
The invention belongs to a kind of on-line overvoltage monitor for electric power system, be specifically related to a kind of on-line overvoltage monitor based on the dual time base Sampling techniques.
Background technology
Along with electric power constant development of economy and user to the improving constantly of electricity consumption quality requirements, requiring of Power System Reliability is increasingly high.The reliability of electric system at first depends on the reliability of electric equipment operation.Yet cause by insulation fault greatly in the damage accident of electrical equipment; Wherein power network overvoltage impacts very big to the insulation of power equipment; Cause the destruction of the insulation of operation power equipment easily, thereby cause electric power accident, having a strong impact on safe operation of power system.
Superpotential is the abnormal voltage that surpasses WV that electric system is occurred under certain condition, belongs to a kind of electromagnetic distu phenomenon in the electric system, and its type is diversified.Its waveform, voltage magnitude, duration and generation reason all have nothing in common with each other; Produce root with regard to it; It is lightning surge and internal overvoltage two major types that superpotential is divided into exterior overvoltage; Wherein lightning surge is the most serious a kind of of infringement power equipment degree, and its wave head is steep, amplitude is high, time compole weak point moment takes place.Carry out correct analysis for the reason that the superpotential accident is taken place, a considerable amount of multi-form superpotential pick-up units have been installed in the electric system.Through the domestic and international patent documentation of online information retrieval, application number is [200510041795.1], and name is called the Chinese invention patent of multiple path transient wave form over voltage of power system online test method and device thereof; Its device is made up of high-voltage bleeder, signal condition unit, collecting unit, industrial computer basically, has realized the on-line monitoring to Hyper-Voltage of Power Systems, but its poor stability; Poor anti jamming capability; The accuracy of sampling is not high, and sampling rate can not be provided with flexibly, measures loop and primary equipment and directly is electrically connected; Influence safety etc., especially monitoring has certain sunken property of office to lightning surge.
Summary of the invention
In order to overcome the deficiency of above-mentioned prior art; The object of the present invention is to provide a kind of on-line overvoltage monitor based on the dual time base Sampling techniques; Employing not only is adapted to the monitoring of Past Voltage within Power System based on the redundant overvoltage signal waveform of gathering of two acquisition modules, and simultaneous adaptation is in the monitoring of electric system exterior overvoltage; Especially the most outstanding to the lightning surge effect, have the accuracy and stable characteristics that improve the superpotential on-line monitoring.
To achieve these goals; The technical scheme that the present invention adopts is: a kind of over-voltage monitoring device based on the dual time base Sampling techniques; Form by capacitance-resistance high-voltage sensor 1, signal condition unit 2, Signal Spacing unit 3, industrial control computer 4, photoelectric isolation module 5 and insulating power supply 6; Capacitance-resistance high-voltage sensor 1 signal output part links to each other with two holding circuit input ends of signal condition unit 2 through double shield layer concentric cable; The input end that the photoelectricity of signal condition unit 2 is isolated the photoelectric isolation module 5 of output terminal and Signal Spacing unit 3 links to each other; The network interface 7 of the output terminal of photoelectric isolation module 5 and industrial control computer 4 links to each other, and insulating power supply 6 output terminals of synchronous signal isolated location 3 and the power input of signal condition unit 2 link to each other;
Signal condition unit 2 is made up of 3 groups of two 9,3 groups of trigger circuit 10 of holding circuit 8,3 component volt circuits, dual time base data acquisition module 11 and first electric light isolation modules 12; The signal input part of two holding circuits 8 links to each other with capacitance-resistance high-voltage sensor 1 signal output part separately; The signal output part of two holding circuits 8 links to each other with the signal input part of bleeder circuit 9; The signal output part of bleeder circuit 9 links to each other with the signal input part of trigger circuit 10; The signal output part of bleeder circuit 9 and the input end of dual time base data acquisition module 11 link to each other simultaneously; The signal output part of trigger circuit 10 links to each other with the trigger end of dual time base data acquisition module 11, and the output terminal of dual time base data acquisition module 11 links to each other with the input end of the first electric light isolation module 12.
Described pair of holding circuit 8 comprises ceramic gas discharge tube DS1; The signal output signal of input termination capacitance-resistance high-voltage sensor 1; And link to each other with the 5th resistance R 5 with ceramic gas discharge tube DS1, first resistance R 1, first capacitor C 1, TVS pipe D1; First capacitor C, 1 other end links to each other with second resistance R 2, ceramic gas discharge tube DS1, first resistance R 1, second resistance R 2 and TVS pipe D1 other end ground connection, and the other end of the 5th resistance R 5 is output terminals.
The in-phase input end pin 14 of the input termination operational amplifier U1 of described bleeder circuit 9; And link to each other with second capacitor C 2, the 3rd capacitor C 3; The other end of the 3rd capacitor C 3 links to each other with the 3rd resistance R 3; The other end ground connection of second capacitor C 2, the 3rd resistance R 3, the inverting input pin 13 of operational amplifier U1 connects the other end of the 4th resistance R 4, the four resistance R 4 and the positive supply pin 16 of operational amplifier U1 links to each other; The output pin 17 of operational amplifier U1 links to each other with+12V direct supply, the 4th capacitor C 4 and capacitor C 5; The other end ground connection of the 4th capacitor C 4 and the 5th capacitor C 5, the negative supply pin 15 of operational amplifier U1 links to each other the other end ground connection of the 6th capacitor C 6 and the 7th capacitor C 7 with-12V direct supply, the 6th capacitor C 6 with the 7th capacitor C 7.
Described trigger circuit 10 comprise double threshold comparer U2; Connect the signal In end after bleeder circuit 9 dividing potential drops; And link to each other with the 6th resistance R 6, the 7th resistance R 7; INB-pin the 24, the 11 resistance R 11 of the other end of the 6th resistance R 6 and double threshold comparer U2 links to each other; The INA+ pin 26 of the other end of the 7th resistance R 7 and double threshold comparer U2, the 8th resistance R 8 link to each other, the other end ground connection of the 11 resistance R 11, the 8th resistance 8, and the INB-pin 24 of double threshold comparer U2 links to each other with the second adjustable potentiometer RP2 movable end, the tenth capacitor C 10; V-pin the 23, the 11 capacitor C 11 of the first end of the second adjustable potentiometer RP2 and double threshold comparer U2, second inductance L 2 link to each other; The other end of second inductance L 2 links to each other with direct supply-5V, electrochemical capacitor C12, the other end ground connection of the end of the second adjustable potentiometer RP2, the 11 capacitor C 11, electrochemical capacitor C12, and the INB+ pin 27 of double threshold comparer U2 links to each other with the first adjustable potentiometer RP1 movable end, the 9th capacitor C 9; The first end of the first adjustable potentiometer RP1 and double threshold comparer U2+V pin 28, the 8th capacitor C 8, first inductance L 1 link to each other; The other end of first inductance L 1 links to each other with+5V direct supply and capacitor C 13, the terminal ground connection of the first adjustable potentiometer RP1, the other end ground connection of the 8th capacitor C the 8, the 13 capacitor C 13, the 9th capacitor C 9; 2 pins 19 of double threshold comparer U2 link to each other with the tenth resistance R 10; 15 pins 32 of double threshold comparer U2 link to each other with the 9th resistance R 9, the GND pin 20 of double threshold comparer U2, LEA pin 21, NC pin 22, NC pin 29, LEB pin 30, GND pin 31 ground connection, the other end ground connection of the 9th resistance R 9, the tenth resistance R 10; The QA pin 18 of double threshold comparer U2 links to each other with the 13 resistance R 13, the second diode D2; The QB pin 33 of double threshold comparer U2 links to each other with the 12 resistance R 12, the 3rd diode D3, the 12 resistance R the 12, the 13 resistance R 13 ground connection, and the second diode D2, the 3rd diode D3 link to each other as the OUT output terminal.
Described dual time base data acquisition module 11 comprises amplifier 34; The signal output part of amplifier 34 links to each other with the signal input part of accurate attenuation filter 35, the signal input part of the signal output part of accurate attenuation filter 35 and converter 36 links to each other; The signal output part of converter 36 links to each other with the input end of configuration logic 37; The signal input part of the amplifier 34 of two dual time base data acquisition modules 11 links to each other with the output terminal OUT of bleeder circuit 9; The output terminal of trigger circuit 10 also links to each other with the signal input part of amplifier 34; The output terminal of configuration logic 37 is that the output terminal of dual time base data acquisition module 11 and the input end of the first electric light isolation module 12 link to each other, and the output terminal of the first electric light isolation module 12 links to each other with the input end of photoelectric isolation module 5.
The present invention can real time on-line monitoring, in the motion tracking electric system external overvoltage, can write down over-voltage waveform and relevant information complete when superpotential takes place, exactly simultaneously; Holding circuit is accomplished the coupling conversion of signal, the security that has improved system, and bleeder circuit carries out dividing potential drop once more; Follow output; Satisfy the needs of acquisition module input coupling, make signal undistorted simultaneously, but true and reliable acquired signal is provided for follow-up accurate digital-to-analog conversion.The capture card real-time sampling rate that adopts can reach 25MS/s, and sampling rate can be set in from 1KS/s to the 25MS/s scope; Every passage 8M high capacity plate carries internal memory; Dual time base data acquisition module 11 possesses 3 synchronized sampling passages; Can write down bus A, B, C three-phase waveform, the bimodulus piece is redundant, with different sampling rates, sampling length to same waveform acquisition; One module is arranged to the details of high sampling rate, low sampling length essential record waveform; Another module is set to low sampling rate, high sampling length essential record waveform overall process, has well solved the problem of sampling rate and storage depth, for the multianalysis of waveform research provides strong assurance.Synchronous signal isolated location 3 provides the power supply through isolating for signal condition unit 2; Digital signal after dual time base data acquisition module 11 will be handled after electric light-opto-electronic conversion with the industrial computer communication; The anti-electromagnetic interference capability of system and the measuring accuracy of system have been improved; On safety, accomplish simultaneously the electrical isolation of transforming plant primary equipment and secondary measuring system, the present invention has long-time running stability, high measuring accuracy and security.
Performance index of the present invention are following:
1, measuring voltage error of the present invention:<2%;
2, step response time<40ns of the present invention (overshoot is not more than 5%);
3, the dielectric level of capacitance-resistance high-voltage sensor 1: (1min) power-frequency withstand voltage (root-mean-square value):>105kV in short-term; Lightning impulse voltage (peak value):>280kV; Tolerance switching overvoltage (peak value)>240kV
4, dual time base data acquisition module 11 sampling rates can be set in the 25MS/s scope at 1KS/s; Sampling length is adjustable, and every passage reaches as high as the 4M point;
5, the triggering threshold voltage of trigger circuit 10 is provided with arbitrarily in 1-5 times of scope of rated voltage.
Description of drawings
Fig. 1 is a structural representation of the present invention.
Fig. 2 is signal condition of the present invention unit 2 structural representations.
Fig. 3 is the structure principle chart of of the present invention pair of holding circuit 8, bleeder circuit 9.
Fig. 4 is the structure principle chart of trigger circuit 10 of the present invention.
Fig. 5 is dual time base data acquisition module 11 structural drawing of the present invention.
Embodiment
Below in conjunction with accompanying drawing structural principle of the present invention and principle of work are done further explain.
With reference to Fig. 1; A kind of over-voltage monitoring device based on the dual time base Sampling techniques; Comprise capacitance-resistance high-voltage sensor 1; Capacitance-resistance high-voltage sensor 1 signal output part links to each other with two holding circuit input ends of signal condition unit 2 through double shield layer concentric cable; The input end that the photoelectricity of signal condition unit 2 is isolated the photoelectric isolation module 5 of output terminal and Signal Spacing unit 3 links to each other, and the network interface 7 of the output terminal of photoelectric isolation module 5 and industrial control computer 4 links to each other, and insulating power supply 6 output terminals of synchronous signal isolated location 3 and the power input of signal condition unit 2 link to each other.
With reference to Fig. 2; Described signal condition unit 2 comprises 3 groups of two holding circuits 8; The signal input part of two holding circuits 8 links to each other with capacitance-resistance high-voltage sensor 1 signal output part separately; The signal output part of two holding circuits 8 links to each other with the signal input part of bleeder circuit 9, and the signal output part of bleeder circuit 9 links to each other with the signal input part of trigger circuit 10, and the signal output part of bleeder circuit 9 and the input end of dual time base data acquisition module 11 link to each other simultaneously; The signal output part of trigger circuit 10 links to each other with the trigger end of dual time base data acquisition module 11, and the output terminal of dual time base data acquisition module 11 links to each other with the input end of the first electric light isolation module 12.
With reference to Fig. 3, described pair of holding circuit 8 comprises ceramic gas discharge tube, TVS pipe, electric capacity, resistance.The output signal of input termination capacitance-resistance high-voltage sensor 1; And link to each other with resistance R 5 with ceramic gas discharge tube DS1, resistance R 1, capacitor C 1, TVS pipe D1; Capacitor C 1 other end links to each other with resistance R 2; Ceramic gas discharge tube DS1, resistance R 1, resistance R 2 and TVS pipe D1 other end ground connection, the other end of resistance R 5 is output terminals.Two holding circuits 8 are imported to one section bus three-phase voltage synchronously, thus can carry out second protection, to guarantee system equipment and staff's safety.
With reference to Fig. 3, the in-phase input end pin 14 of the input termination operational amplifier U1 of described bleeder circuit 9, and link to each other with capacitor C 2, capacitor C 3; The other end of capacitor C 3 links to each other with resistance R 3; The other end ground connection of capacitor C 1, resistance R 3, the inverting input pin 12 connecting resistance R4 of operational amplifier U1, the other end of resistance R 4 gets pin 16 with operational amplifier U1 and links to each other; The pin 17 of operational amplifier U1 links to each other with capacitor C 5 with+12V direct supply, capacitor C 4; The other end ground connection of capacitor C 4 and capacitor C 5, the pin 15 of operational amplifier U1 links to each other the other end ground connection of capacitor C 6 and capacitor C 7 with-12V direct supply, capacitor C 6 with capacitor C 7.9 pairs one section bus three-phase voltage parallel sensor output of bleeder circuit signal carries out dividing potential drop once more, satisfies the needs of acquisition module input coupling simultaneously, guarantees that signal is undistorted in claimed range, can accurately measure.
With reference to Fig. 4; Described trigger circuit 10 comprise double threshold comparer, inductance, adjustable potentiometer, electric capacity, resistance, diode, connect the signal In end after bleeder circuit 9 dividing potential drops, and link to each other with resistance R 6, R7; INB-pin 24, the resistance R 11 of the other end of resistance R 6 and double threshold comparer U2 link to each other; INA+ pin 26, the resistance R 8 of the other end of R7 and double threshold comparer U2 link to each other, the other end ground connection of resistance R 11, resistance 8, and the INB-pin 25 of double threshold comparer U2 links to each other with adjustable potentiometer RP2 movable end, capacitor C 11; V-pin 23, capacitor C 11, the inductance L 2 of the first end of adjustable potentiometer RP2 and double threshold comparer U2 link to each other; The other end of inductance L 2 links to each other with direct supply-5V, electrochemical capacitor C12, the other end ground connection of the end of adjustable potentiometer RP2, capacitor C 11, electrochemical capacitor C12, and the INB+ pin 27 of double threshold comparer U2 links to each other with adjustable potentiometer RP1 movable end, capacitor C 9; The first end of adjustable potentiometer RP1 and double threshold comparer U2+V pin 28, capacitor C 8, inductance L 1 link to each other; The other end of inductance L 1 links to each other the terminal ground connection of adjustable potentiometer RP1, the other end ground connection of capacitor C 8, capacitor C 13, capacitor C 9 with+5V direct supply and capacitor C 13; 2 pins 19 of double threshold comparer U2 link to each other with resistance R 10; 15 pins 32 of double threshold comparer U2 link to each other with resistance R 9, the GND pin 20 of double threshold comparer U2, LEA pin 21, NC pin 22, NC pin 29, LEB pin 30, GND pin 31 ground connection, the other end ground connection of resistance R 9, resistance R 10; The QA pin 18 of double threshold comparer U2 links to each other with resistance R 13, diode D2; The QB pin 33 of double threshold comparer U2 links to each other with resistance R 12, diode D3, resistance R 12, resistance R 13 ground connection, and diode D2, diode D3 link to each other as the OUT output terminal.Trigger circuit 10 can be judged to the signal of one section bus three-phase voltage respectively; Whether generate trigger pip; Compare according to trigger pip level that is provided with in advance and the live signal after the busbar voltage dividing potential drop, when equaling or exceeding the trigger pip level that is provided with in advance, generate trigger pip, three-phase is independent; Relatively certain phase of back, two phases or three-phase generate trigger pip simultaneously, give the acquisition module trigger end as gathering the enabling signal that waveform is preserved through gathering.
With reference to Fig. 5; Described dual time base data acquisition module 11 comprises amplifier 34; The signal output part of amplifier 34 links to each other with the signal input part of accurate attenuation filter 35, the signal input part of the signal output part of accurate attenuation filter 35 and converter 36 links to each other; The signal output part of converter 36 links to each other with the input end of configuration logic 37; The signal input part of the amplifier 34 of two dual time base data acquisition modules 11 links to each other with the OUT output terminal of bleeder circuit 9; The output terminal of trigger circuit 10 also links to each other with the signal input part of amplifier 34, and the output terminal of configuration logic 37 is that the output terminal of dual time base data acquisition module 11 and the input end of the first electric light isolation module 12 link to each other, and the output terminal of the first electric light isolation module 12 links to each other with the input end of photoelectric isolation module 5.
Principle of work of the present invention is:
The present invention's use in the Hyper-Voltage of Power Systems on-line monitoring is:
The first step: be in start and carried out parameter setting and initialization based on the on-line overvoltage monitor of dual time base Sampling techniques, the superpotential triggering level is arranged on 1.5 times of rated voltage or regulate according to user's request;
Second step: just at the acquired signal waveform, wait for that trigger circuit 10 transmit trigger pip based on the dual time base data acquisition module 11 in the on-line overvoltage monitor of dual time base Sampling techniques;
The 3rd step: differentiate superpotential whether occurs; When the voltage magnitude absolute value that records based on dual time base data acquisition module 11 on-Line Monitor Device is not less than set-point; Confirm as electrical network and superpotential occurs, dual time base data acquisition module 11 bases triggered in advance to be provided with and carried out data storage this moment; The voltage magnitude absolute value that records when on-Line Monitor Device is during less than set-point, and system repeated for second step;
The 4th step: in the data upload industrial control computer 4 with 11 collections of dual time base data acquisition module; The signal that industrial control computer 4 is uploaded the Double Data acquisition module deposits its buffer memory in, deposits its hard disk in the form of file;
The 7th step: whether the judgment data storage is accomplished, and data storage finished to carry out again second step.
Capture program of the present invention mainly realizes to superpotential on-line monitoring, after the storage of motion tracking, data waveform, accomplishes with many inputs oscillograph realization of Design of Virtual Instrument functions such as the inquiry of preserving the superpotential historical data, operation, digital filtering, analyses through routine analyzer.Carry out data query through database earlier the data call that selection is accomplished in the back is set, report output to the detailed operation of waveform, through researching and analysing after the processing such as spectrum transformation, digital filtering, can be passed through at last in the SELCH again.
When superpotential appears in electrical network; Voltage signal is after the capacitance-resistance high-voltage sensor carries out dividing potential drop, and lower voltage signal is sent to the signal condition unit through double shielded coaxial cable, and the lower voltage signal in the signal condition unit is through after the dividing potential drop; Be sent to the dual time base data acquisition module; After trigger pip was arranged, the dual time base data acquisition module carried out uploading industrial computer after the data acquisition, industrial computer to data store, echo, analysis.