Ac short circuit absence of discharge type insulator detection method
The present invention has realized a kind of insulating resistance value of measuring insulator in high temperature, the extra high voltage network under electriferous state, and under electriferous state, can measure the insulating resistance value of insulator among the high voltage transmission line accurately, identification has been leaked electricity but has not been punctured the method for the insulator be in the critical damage state as yet, and with the pick-up unit of this method realization.A kind of ac short circuit absence of discharge type insulator pick-up unit or instrument that the technical field of the invention provides for high-tension power transmission and transformation equipment.
Be installed in the insulator on the transmission line of electricity, in the operational process of electrical network insulator because of stand for a long time dynamo-electric to load, expose to the sun and rain, effect such as cold and hot variation, faults such as insulation resistance reduction, cracking even puncture may appear, power supply reliability is brought potential threat, therefore cause damage in order to reduce to have a power failure, so insulator charged detection is significant.
The charged detection of line insulator because of the singularity of its installation site and the popularity of distributed areas, always all is the difficult point that charged insulation detects.In a single day insulator goes wrong and just must change immediately, otherwise will influence the security of operation of ultra-high-tension power transmission line.
Several years, training more effective more reliable quantitative detecting method and device both at home and abroad always, up to the present, very effective inadequately to the detection method and the device of high-voltage transmission line insulator.Domestic also a large amount of traditional detection mode of using artificial work high above the ground, this detection mode poor stability, detection efficiency is low.Though adopted mechanical work to replace traditional detection means abroad, also all there is a large amount of defectives in several detection modes that adopt, can't adapt to the requirement of modern power network, and cost are high especially.The detection mode of mechanization at present is broadly divided into three kinds based on different detection principles.
Voltage distribution: be that the voltage distribution of insulator is measured, then corresponding measured value is calculated, judge by the result of calculation that obtains whether tested insulator is normal, the calculating of lid method is very complicated, computational data is many, computing method is not accurate enough, but the also result that can only obtain finalizing the design, and to the requirement height of computing machine, cost height.
The bead electric discharge: the distance the when bead that is connected to insulator by measurement produces electric discharge phenomena, judge the voltage at insulator two ends, the indirect voltage distribution situation of knowing tested insulator, thus whether detect tested insulator normal.
Far infrared detection method: by the far infrared that tested insulator sent is surveyed, whether do not have the corresponding insulation of judgement by its ultrared distribution of sending then normal, the use of this method needs good, stable meteorological condition, otherwise the interference that the measurement of outer bound pair is caused can't overcome.
On the basis of these three kinds of traditional detection methods, the researchist has implemented different technology to these detection methods, finishes the detection to insulator on the transmission line of electricity.Wherein, 200510063334.4 introduced a kind of insulator charged detection instrument and detection method in number Chinese patent, wherein by setting to the electric field detection probe, the mean value of measuring pad present position electric field, the Electric Field Numerical in the pole plate centre position of probe, by a series of electric field data of the motion measurement of detector, obtain insulator surface Electric Field Distribution curve by computing machine, this detection method is typical voltage distribution, computational data is many, account form complexity, cost height, and result calculated is the result of three measured places only also, absence of discharge type insulator accurately, complete detection.That puts down in writing in 01134527.6 and No. 01270277.3 Chinese patent all belongs to a kind of high-voltage transmission line insulator live pick-up unit, its principle of work is basic identical, all be to apply detection voltage at the two ends of detected insulator, extraction applies the voltage of voltage, current sampling data, calculate the insulation resistance of detected insulator according to sampled data, analyze its state of insulation, in fact this detection belongs to electric discharge, be by having changed the detection data, data processing method and decision procedure, by means of repeatedly sampling, with sampled voltage mean value, sample rate current mean value is estimated the resistance of insulator.This mode, be subjected to the influence of many-sided factors such as the individual resistance difference of insulator under sampling number, sample mode and the outdoor environment, and key is that this detection mode can not well detect the Weak current variation, can't realize the accurate detection to insulator.Having put down in writing high-voltage transmission line insulator live in 01201765.5 and No. 01102273.6 Chinese patent can only detector, use therein detection mode is identical with detection principle in above-mentioned two patents, central controller circuit, sensor circuit, sample circuit, driving circuit etc. have been adopted, wherein implement the circuit complexity, the cost height, and can't realize the Weak current collection, and employed central controller can not well satisfy the demands in handling the current sample sample.Though, the method for a part of detection insulator is disclosed in the patented technology both domestic and external, all there is defective in these methods, and all exist in resistance detection than mistake, can accurately not detect the resistance of insulator.Therefore the result who causes can't measure the resistance value of every insulator accurately, can't discern to have leaked electricity but puncture the insulator that is in the critical damage state as yet.At present, the detection technique of the U.S., Germany's employing in insulator detects also can't overcome above-mentioned defective.
Summary of the invention
The invention provides the method that a kind of high-voltage transmission line insulator live detects, this method can make ultra-high-tension power transmission line be under the electriferous state, accurately measure the insulating resistance value on each sheet insulator on it, identification has been leaked electricity but has not been punctured the insulator that is in the critical damage state as yet.
Adopt ac short circuit electric capacity, Weak current acquisition interface circuit, voltage collection circuit and voltage detection signal arrangement interface circuit among the present invention, can accurately detect insulator voltage and leakage current on every side, guaranteed the accuracy of data.The circuit structure that adopts is simple, and cost is low, and has realized the Weak current collection.
The present invention has adopted MCU Computer Processing chip, and this chip functions is powerful, can handle electric current and the voltage signal that collects fast, in time, accurately, and be translated into digital signal, can realize Digital Control, has improved the sensitivity that detects.
The present invention's ac short circuit electric capacity that is connected in series between two detection terminals detects detected voltage between the terminal by divider resistance is set.Wherein be connected in series between two detection terminals ac short circuit electric capacity and with two branch pressure drags of connecting of ac short circuit electric capacity parallel connection.
Ac short circuit under the two ends duty of detection terminal among the present invention, the voltage signal by divider resistance by detection signal arrangement interface circuit after, be sent to the MCU computer chip and carry out computing and be converted to digital signal.
The invention provides a kind of device of insulator charged detection of ultra-high-tension power transmission line, this device can be when ultra-high-tension power transmission line moves, by directly being connected the voltage and the electric current leak data thereof of gathering on this insulator with insulator.
It is the method that a kind of high-voltage transmission line insulator live detects that ac short circuit absence of discharge type insulator detects, carry out ac short circuit (absence of discharge) at the two ends of tested insulator, measure the voltage and the current value of this detection voltage then, can calculate the insulating resistance value of tested insulator by this magnitude of voltage and current value with Ohm law.
When measuring tested insulator, by MCU computing chip (6) respectively to this measurement than leakage current in the magnitude of voltage of divider resistance in the closed-loop path and the circuit, thereby obtain calculating the required magnitude of voltage of insulator resistance value and the magnitude of current.
Description of drawings
Fig. 1 is the circuit theory diagrams of detecting unit among the present invention.
Fig. 2 is the circuit theory diagrams of MCU computing chip of the present invention.
Fig. 3 is the data processing and the memory circuit schematic diagram of band communication interface of the present invention and display interface.
Fig. 4 is the clock circuit interface circuit figure that the present invention is connected with MCU computing chip.
Fig. 5 is that demonstration of the present invention is provided with the man-machine interface circuit diagram.
Fig. 6 is an equipment schematic of the present invention.
Fig. 7 is a schematic block circuit diagram of the present invention.
Equipment schematic of the present invention and schematic block circuit diagram are as can be known, the present invention is by applying signal to measured insulator, testing circuit by two terminals connections, acquire the signal of electric field on every side that is applied on the terminal, obtain current value by the Weak current Acquisition Circuit, specific voltage testing circuit by the composition of the bleeder circuit in the testing circuit, set the good detection point, adopt the detection signal arrangement interface circuit of the voltage of U3MAX407-(8) composition to obtain voltage signal accurately, detected Weak current signal and voltage signal are sent to MCU computing chip together, under the effect of clock signal circuit, MCU computing chip measurement voltage signal value repeatedly can be superposeed and comprehensively each time numerical value obtain its average voltage level, reduce measuring error, by the Weak current that repeatedly measure to obtain superpose obtain and and comprehensive each time numerical value obtain its average voltage level, reduce the signal errors that measuring error and processing of circuit are brought, the electric current and the voltage signal that obtain are handled by data processing and memory circuit, by MCU computing chip above-mentioned two signals are carried out digital processing again, obtain the resistance value of detected insulator.Wherein, the resistance value that obtains is transmitted out and by demonstration the man-machine interface circuit is set and shows, whether compare by the numerical value with normal insulation of setting, can judge directly whether detected insulator is normal, directly demonstrating needs to change this insulator.
Fig. 1 is the circuit theory diagrams of detecting unit, and wherein detecting unit comprises testing circuit, Weak current Acquisition Circuit, detection signal arrangement interface circuit.Wherein, testing circuit comprises the ac short circuit electric capacity of C10 (5000P) and the circuit of bleeder circuit composition etc.Wherein joint detection terminal (1) and detection terminal (2) are distinguished in the two ends of detected insulator, under the effect of the ac short circuit electric capacity of C10 (5000P), by divider resistance R15 and R16, wherein divider resistance R16 is in parallel with setting electric capacity, can obtain tested voltage, this tested voltage signal carries out the A/D conversion via MCU computing chip (6) after putting interface circuit (4) processing in order by detection signal, and tested analog quantity is converted to digital quantity.The Weak current Acquisition Circuit is made of the controlled short-circuiting device of Weak current acquisition interface (3), wherein pass through the circuit of Weak current acquisition interface (3), can obtain tested Weak current signal, after this current signal is put interface (4) processing in order by detection signal, carrying out the A/D conversion via MCU computing chip (6), is digital quantity with tested analog quantity.
Fig. 2 is the circuit theory diagrams of MCU computing chip of the present invention.The voltage and the current value that obtain after MCU computing chip (6) the A/D conversion may calculate the resistance value of tested insulator: calculating voltage value and leakage current value; According to magnitude of voltage and current value, calculate the insulating resistance value of tested insulator by Ohm law.
Fig. 3 is the data processing and the memory circuit schematic diagram of band communication interface of the present invention and display interface.Data processing is connected with real interface with communication interface with memory circuit, and its output detection architecture signal outputs to this interface.The course of work can be known by circuit diagram.
Fig. 4 is the clock circuit interface circuit figure that the present invention is connected with MCU computing chip.Fig. 5 is that demonstration of the present invention is provided with the man-machine interface circuit diagram.
Fig. 6 is an equipment schematic of the present invention.The formation of device is shown in pick-up unit structural drawing (B): this device is by detection terminal (1) and detection terminal (2), detect synchro switch (3), display panel and detection task are provided with button (4), and part such as the type of attachment (6) of insulating bar (5) and pick-up unit universal joint and insulating bar constitutes.Detection terminal (1) is connected with the two ends of detection terminal (2) with on-the-spot tested insulator, by detection terminal (1), detection terminal (2), ac short circuit electric capacity and divider resistance constitute the occlusion detection loop, connect with intelligent control chip by testing circuit, thus the measurement of realization insulator resistance value.Detecting synchro switch (3) control survey begins.The resistance value of tested insulator can show in real time by display panel, and the user can also come the manual detection task that is provided with by the button on the display panel (4), and shows task number and phase sequence.This pick-up unit is to adopt the universal joint mode with being connected of insulating bar.Purpose is to satisfy the detection adjustment of various stations.Make things convenient for the workman to operate.
A kind of ac short circuit absence of discharge type insulator detection method, comprising following steps:
A, pick-up unit front end connect two two ends and the chuckings that detect the insulator of steel wire contact electrification respectively, place detection terminal (1), (2) in this insulator symmetria bilateralis, under the effect of the alternating circuit electric capacity by connecting this detection terminal (1), (2), by two divider resistances, detectable voltage signals, after putting detectable voltage signals the processing of circuit of interface (4) in order by detection signal, carry out the A/D conversion through MCU computing chip (6), detected voltage signal is converted to digital signal;
B, obtain by the current signal in this detection terminal (1), (2) by the Weak current Acquisition Circuit that is connected with this detection terminal (1), (2) and alternating circuit electric capacity, after this current signal is sent to the processing of circuit of detection signal arrangement interface (4) by Weak current Acquisition Circuit interface (3), carry out the A/D conversion through MCU computing chip (6), detected current signal is converted to digital signal;
C, can insulator be taken multiple measurements, above-mentioned voltage digital signal is superposeed, obtain the average voltage of measuring by data processing and memory circuit by the position of this detection terminal of conversion (1), (2);
D, can insulator be taken multiple measurements, above-mentioned current digital signal is superposeed, obtain the current average of measuring by data processing and memory circuit by the position of this detection terminal of conversion (1), (2);
E, MCU computing chip be according to the ratio of above-mentioned average voltage and current average, obtains the resistance value of above-mentioned charged insulator;
F, by resistance value that man-machine interface circuit output E step calculates being set to this display interface with demonstration that above-mentioned data processing and memory circuit are connected with above-mentioned MCU computing chip (6);
G, by detecting the beginning of synchro switch control survey.
Ac short circuit absence of discharge type insulator detection method according to the present invention is provided with ac short circuit absence of discharge type insulator detector.This detector can detect high-voltage transmission line insulator live, comprising: be connected to the detecting unit of detected insulator with detection signal output; To the control module that detection signal is handled and exported, accept the man-machine interface unit of user's input information and video data information.
Detecting unit comprises: protection housing, testing circuit are used for the insulating bar of joint detection instrument and the pick-up unit of front end: the pick-up unit front end is connected two respectively and detects steel wire connect insulator two ends and chucking, and obtains good reliable contact.
Control module comprises: sampling and change-over circuit, communication interface circuit.
The man-machine interface unit comprises: user's keyboard and data presentation interface circuit thereof.
Testing circuit wherein; sampling and change-over circuit, communication interface circuit all are installed in the protection enclosure interior; and the output terminal of this detecting unit is connected to the input end of sampling and change-over circuit thereof; sampling and change-over circuit are connected with communication interface circuit and display interface circuit by MCU computing chip (6), and external unit carries out data communication by this communication interface circuit and this control module.
The protection housing uses metal material to constitute.
Testing circuit comprises: Weak current Acquisition Circuit interface (3), detection signal arrangement interface (4) and two detection terminals (1) and detection terminal (2):
The two ends of voltage detecting circuit are connected respectively to detection terminal (1) and detection terminal (2); It does not detect the voltage detection signal output terminal that deferent segment is connected to the input/output signal interface;
Sampling and change-over circuit comprise: MCU computing chip (6), clock circuit interface (7), data processing and memory circuit, output interface;
Data processing is connected with real interface with communication interface with memory circuit, and its output detection architecture signal outputs to this interface.