CN2718591Y - Dielectric loss on-line monitoring device for capacitive electric equipment - Google Patents

Dielectric loss on-line monitoring device for capacitive electric equipment Download PDF

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Publication number
CN2718591Y
CN2718591Y CN 200420041921 CN200420041921U CN2718591Y CN 2718591 Y CN2718591 Y CN 2718591Y CN 200420041921 CN200420041921 CN 200420041921 CN 200420041921 U CN200420041921 U CN 200420041921U CN 2718591 Y CN2718591 Y CN 2718591Y
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signal
dielectric loss
line monitoring
power equipment
capacitor type
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成永红
陈小林
张少锋
石山
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Xian Jiaotong University
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Xian Jiaotong University
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Abstract

The utility model discloses a dielectric loss on-line monitoring device for capacitive electric equipment. The equipment earth connection is sheathed with high precision micro current sensor, and a resistance voltage divider is arranged on the low-voltage output of the substation voltage transformer. The dielectric loss on-line monitoring device for capacitive electric equipment makes use of computer to analyze, process and display the result, and realizes the signal online monitoring of the power equipment leakage current. The dielectric loss on-line monitoring device for capacitive electric equipment is composed of the high precision micro current sensor, the resistance voltage divider, a signal cable, a signal conditioner, a data collecting card, a digital IO card and a computer. The method and the device of the utility model can calibrate the phase excursion caused by the hardware according to the size of the equipment leakage current value, and charge off the abnormal value of measuring, and account the dielectric loss by spectrum analysis method and correlation method. The methods can guarantee the measuring accuracy, and the dielectric loss on-line monitoring device for capacitive electric equipment also accounts the mean square value of the power equipment leakage current. The dielectric loss on-line monitoring device for capacitive electric equipment realizes the data administration by ORACLE, and has the functions of history querying, report printing, thresholding alarming and remote querying.

Description

Capacitor type power equipment dielectric loss on-Line Monitor Device
Technical field
The invention belongs to power equipment on-line monitoring technique field, relate to a kind of device of on-line monitoring capacitor type power equipment dielectric loss.
Background technology
Rapid development of national economy further improves the requirement of Operation of Electric Systems reliability, and the power equipment on-line monitoring technique is the important channel of improving the operation power reliability.The capacitor type power equipment occupies very big ratio in power transmission and transformation system, as transformer, cable, sleeve pipe etc., these power equipments are subjected to the effect of factors such as electricity, heat, machinery, environment and wear out in operational process, decreasing insulating becomes accident potential.Dielectric loss is the important insulation index of reflection capacitor type power equipment insulation status, and the dielectric loss of on-line monitoring power equipment can effectively be judged the insulation ag(e)ing situation of power equipment, and the stable operation of power equipment is had a very important role.
The power equipment dielectric loss pick-up unit of exploitation can be divided into two types both at home and abroad, and a kind of is off-line measurement, and this measurement mechanism needs tested equipment is had a power failure in use, is suitable for preventive trial; Another kind of live line measurement, this measurement mechanism can be measured when equipment normally moves.Existing power equipment dielectric loss live line measurement device is the calculation process core with the single-chip microcomputer, as Chinese patent publication number 1185585 and Chinese patent publication number 2200823, be subjected to the restriction of single-chip microcomputer function, cause the function of device fairly simple, do not have high-level data managerial ability and teledata query function, digital signal processing capability is poor simultaneously, is difficult to the on-the-spot strong electromagnetic signal of filtering.Chinese patent publication number 1188237 has been announced a kind of method and device thereof of live line measurement medium loss of capacitive electric equipment, this device adopts principle of balance bridge and electric capacity, resistance to unite sampling, can improve measuring accuracy, but this device needs manual adjustments, is not suitable for real-time automatic monitoring.
Along with fast development of national economy, an urgent demand improves the operation power reliability, be to handle the pick-up unit of core in the past with the single-chip microcomputer, be difficult to satisfy the requirement that operation power department increases day by day to the automatization level of equipment because function is simple, and automatization level is lower.
Summary of the invention
The purpose of this utility model is, adopt virtual instrument technique, a kind of device of capacitor type power equipment on-line monitoring equipment is provided, have measuring accuracy height, friendly interface, powerful, automatization level advantages of higher, can satisfy pressing for of capacitor type power equipment dielectric loss automatic monitoring.By the dielectric loss of on-line monitoring capacitor type power equipment, can reflect the insulation status of equipment, in time find insulation defect, eliminate potential faults.
The technical scheme that realizes above-mentioned purpose is, the device of capacitor type power equipment dielectric loss on-line monitoring method carries out the signal transmission by signal cable, and this device comprises:
Be socketed in the high precision low current sensor on the equipment ground line, be used for coupling electrical power equipment leakage current signal;
The a pair of signal conditioner that is installed in Control Room is used for that signal to the high precision low current sensor amplifies, filtering, Signal Spacing, multichannel selects to handle;
Be arranged on the resitstance voltage divider of transformer substation voltage mutual inductor end, be used to obtain reference voltage signal;
One data collecting card is used for the signal of signal conditioner after amplification, filtering, Signal Spacing, multichannel are selected to handle gathered;
One digital I is used for control signal conditioner, data collecting card passage gating, gain-adjusted and filtering;
One computing machine is used to realize that the data processing of capacitor type power equipment dielectric loss, result show, report to the police, and remote monitoring;
The high precision low current sensor and the resitstance voltage divider thereof that are socketed on the equipment ground line are sent into signal in the data collecting card by the control signal conditioner, computing machine is communicated with data collecting card, digital I respectively, digital I also with the communication of control signal conditioner.
Some other characteristics of the present invention are that described high precision low current sensor adopts the Luo-coil current sensor, is made of external shield box, magnetic core, coil, integrating resistor, signal output plug and amplifying circuit.
The magnetic core of described Luo-coil current sensor is annular sloping film alloy magnetic core.
Described integrating resistor is 50 Ω, and the characteristic impedance of signal output plug also is 50 Ω.
Described resitstance voltage divider has A, B, C three-phase, respectively corresponding the A of power equipment, B, C three-phase.
Described resitstance voltage divider is selected powerful resistance polyphone dividing potential drop for use, and power is 4W.
The highest real-time sampling speed of described data collecting card is 20MS/s, and analog bandwidth is 15MHz, 8 of A/D resolution, and input voltage range-5V～+ 5V, and the two-way input end of analog signal is arranged.
Described digital I has three ports, and 8 of each ports are formed a control word, writes control word and realize control function on each port.
The utility model adopts design of Virtual Instrument thought, by analog input card and and computing machine make up the collection and the analysis platform of device, have characteristics such as friendly interface, computing function are strong.The utility model can be used in the dielectric loss and the leakage current values of on-line monitoring capacitor type power equipment, can calibrate the different phase deviation that hardware circuit causes according to the size of leakage current values, can the rejecting abnormalities result, realize the management of data by the ORACLE database, have the inquiry of historical data function, also have functions such as report printing, Threshold Alerts, remote inquiry simultaneously.
Description of drawings
Fig. 1 is a composition structural representation of the present utility model, and data acquisition engaging digital I is pci bus among Fig. 1, and these two cards all are to be inserted on the PCI slot of computing machine.
Fig. 2 is the cell winding synoptic diagram;
Fig. 3 is resitstance voltage divider structural representation (wherein R1 is 500k Ω, and R2 is 2.5k Ω).
Embodiment
The present invention is described in further detail below in conjunction with accompanying drawing.
Referring to 1, the device of capacitor type power equipment dielectric loss on-line monitoring method involved in the present invention carries out the signal transmission by signal cable, and this device comprises:
Be socketed in the high precision low current sensor 1 on the equipment ground line, be used for coupling electrical power equipment leakage current signal;
The a pair of signal conditioner 2 that is installed in Control Room is used for that signal to high precision low current sensor 1 amplifies, filtering, Signal Spacing, multichannel selects to handle;
Be arranged on the resitstance voltage divider 3 of transformer substation voltage mutual inductor end, be used to obtain reference voltage signal;
One data collecting card 4 is used for the signal of signal conditioner 2 after amplification, filtering, Signal Spacing, multichannel are selected to handle gathered;
One digital I 5 is used for control signal conditioner 2, data collecting card 4 passage gatings, gain-adjusted and filtering;
One computing machine 6 is used to realize that the data processing of capacitor type power equipment dielectric loss, result show, report to the police, and remote monitoring;
Data collecting card 4 and digital I 5 are pci bus, and these two cards all are to be inserted on the PCI slot of computing machine 6.
The high precision low current sensor 1 and the resitstance voltage divider 3 thereof that are socketed on the equipment ground line are sent into signal in the data collecting card 4 by control signal conditioner 2, computing machine 6 is communicated with data collecting card 4, digital I 5 respectively, and digital I 5 is gone back and 2 communications of control signal conditioner.
The high precision low current sensor adopts the Luo-coil current sensor, is made of external shield box, magnetic core, coil, integrating resistor, signal output plug and amplifying circuit.Wherein magnetic core is annular sloping film alloy magnetic core, and concrete size depends on the ground wire sectional area of institute's monitoring equipment.Coil adopts enameled wire coiling (referring to Fig. 2), and the number of turn depends on the size of equipment leakage current, general 100～700 circles.Integrating resistor is 50 Ω, and the characteristic impedance of signal output plug also is 50 Ω.Sensor disturbs for the technology of covering suppresses on-the-spot, and shielding material from the inside to surface is followed successively by sloping film alloy firm, iron sheet film, copper shield box.The amplifying circuit of sensor adopts multistage amplifying technique, and total magnification is between 105～107,4 rank scalable.
Resitstance voltage divider is used for dividing potential drop (referring to Fig. 3) from the voltage transformer (VT), obtains voltage signal, as the phase reference information of analyzing dielectric loss.Resitstance voltage divider has A, B, C three-phase, respectively corresponding the A of power equipment, B, C three-phase.Resitstance voltage divider select powerful resistance polyphone dividing potential drop for use, resistance is respectively 500k Ω and 2.5k Ω, power all is 4W.
Calculate the angular difference between these two kinds of signals, the specific implementation method is; Be socketed in the high precision low current sensor Coupling device leakage current signal on the equipment ground line, being transferred to the signal conditioner that is positioned at Control Room through signal cable amplifies, filtering, Signal Spacing, after multichannel selections etc. are handled, be sent to the data collecting card first passage that is installed in the computing machine and carry out data acquisition, processing such as isolate through sending into signal conditioner after the signal cable transmission, being sent to the data collecting card second channel that is installed in the computing machine and the leakage current signal of first passage gathers simultaneously, calculate the angular difference of current signal and voltage signal, and through calibration, asking for tangent value is exactly the dielectric loss of equipment.This device can be tried to achieve the effective value of current signal, the just effective value of equipment ac leakage current simultaneously.
Signal conditioner is installed in Control Room, can carry out program control amplification, filtering, multichannel selection, Signal Spacing to leakage current signal, also can carry out Signal Spacing to the output signal of resitstance voltage divider.Program control amplification that this device has or attenuation multiple have 1,2,5,10,20,50,100 times, select suitable enlargement factor, and discharge signal is nursed one's health analog input card optimum signal input range, the quantization error when changing to reduce capture card A/D.This device has the low-pass filtering module of 100Hz, to reduce the undesired signal that current signal may be introduced through long Distance Transmission the time.This device has the multichannel selection function, because it has a plurality of signal input parts, comprise the leakage current signal of power equipment three-phase and the phase reference voltage signal of resitstance voltage divider output, when each the detection, need select one road leakage current signal and one road phase reference voltage signal to handle.
The highest real-time sampling speed of the data collecting card that is adopted is 20MS/s, and analog bandwidth is 15MHz, 8 of A/D resolution, and input voltage range-5V～+ 5V.This jig has the two-way input end of analog signal, can gather leakage current signal and voltage reference signal simultaneously.
The digital control jig that is adopted has three ports, and 8 of each ports are formed a control word, can write control word on each port and realize control function.By this digital control card control passage gating, gain-adjusted and filtration module.
Computer implemented function comprises collection, calculating, calibration, abnormal results rejecting, demonstration as a result, Threshold Alerts, report printing, Network Transmission etc.The computer control analog input card is gathered leakage current signal and voltage reference signal simultaneously, adopts Spectral Analysis Method and correlation method to calculate their angular difference, spectrum analysis according to the following equation:
I ( t ) = I 0 + Σ n = 1 ∞ A n sin ( nωt + Φ in ) , U ( t ) = U 0 + Σ n = 1 ∞ B n sin ( nωt + Φ un ) , I in the formula, U are respectively the first passage of capture card and the data that second channel is gathered, I 0, U 0Be respectively their DC component, A n, B nBe respectively the amplitude of nth harmonic, Φ nPhase value for nth harmonic.The fundamental phase of two channel signals, i.e. Φ when adopting this method to obtain n=1 I0And Φ U0, tan δ=tan (Φ I0-Φ U0).
Correlation analysis method is according to the following equation:
Figure Y20042004192100083
Wherein, R xy ( 0 ) = 1 N Σ i = 0 N - 1 x ( i ) y ( i ) , R x ( 0 ) = 1 N Σ i = 0 N - 1 x 2 ( i ) , R y ( 0 ) = 1 N Σ i = 0 N - 1 y 2 ( i ) , X (i) and y (i) are respectively the first passage of capture card and the data that second channel is gathered, and N is a sampling number.
The tangent value of being tried to achieve is the dielectric loss of equipment, size according to leakage current values is calibrated the result,, because of the phase deviation that different leakage current values was produced the abnormal results that calculates is rejected with the compensation hardware circuit, computing machine is also asked for the effective value of leakage current.Finish after the calculation of parameter, computing machine carries out the result and shows, reports to the police, by ORACLE database storing measurement data.Web server software has been installed on computers, and the long-distance user can utilize InternetExplorer, by visiting the IP address of computing machine in this device, can check current monitoring result and enquiry of historical data.
The applicant has finished one in model machine according to the solution of the present invention, by analog input card and and computing machine make up the collection and the analysis platform of device, have characteristics such as friendly interface, computing function are strong.Through evidence, can be used in the dielectric loss and the leakage current values of on-line monitoring capacitor type power equipment, can calibrate the different phase deviation that hardware circuit causes according to the size of leakage current values, can the rejecting abnormalities result, realize the management of data by the ORACLE database, have the inquiry of historical data function, also have functions such as report printing, Threshold Alerts, remote inquiry simultaneously.

Claims (8)

1. the device of a capacitor type power equipment dielectric loss on-line monitoring method carries out the signal transmission by signal cable, it is characterized in that this device comprises:
One is used for the high precision low current sensor (1) of coupling electrical power equipment leakage current signal, and this high precision low current sensor (1) is socketed on the equipment ground line;
A pair of be used for to signal amplify, the signal conditioner (2) handled is selected in filtering, Signal Spacing, multichannel, this signal conditioner (2) is installed in Control Room;
One is used to obtain the resitstance voltage divider (3) of reference voltage signal, and this resitstance voltage divider (3) is arranged on transformer substation voltage mutual inductor end;
One is used for data collecting card (4) that the signal of signal conditioner (2) after amplification, filtering, Signal Spacing, multichannel are selected to handle gathered;
One is used for the digital I (5) of control signal conditioner (2), data collecting card (4) passage gating, gain-adjusted and filtering;
One is used to realize the computing machine (6) of data processing, result's demonstration, warning and the remote monitoring of capacitor type power equipment dielectric loss;
High precision low current sensor (1) and resitstance voltage divider (3) thereof are sent into signal in the data collecting card (4) by control signal conditioner (2), computing machine (6) is communicated with data collecting card (4), digital I (5) respectively, and digital I (5) is gone back and control signal conditioner (2) communication.
2. the device of capacitor type power equipment dielectric loss on-line monitoring method as claimed in claim 2, it is characterized in that, described high precision low current sensor (1) adopts the Luo-coil current sensor, is made of external shield box, magnetic core, coil, integrating resistor, signal output plug and amplifying circuit.
3. the device of capacitor type power equipment dielectric loss on-line monitoring method as claimed in claim 3 is characterized in that, the magnetic core of described Luo-coil current sensor is annular sloping film alloy magnetic core.
4. the device of capacitor type power equipment dielectric loss on-line monitoring method as claimed in claim 3 is characterized in that described integrating resistor is 50 Ω, and the characteristic impedance of signal output plug also is 50 Ω.
5. the device of capacitor type power equipment dielectric loss on-line monitoring method as claimed in claim 2 is characterized in that described resitstance voltage divider (3) has A, B, C three-phase, respectively corresponding the A of power equipment, B, C three-phase.
6. as the device of claim 2 and 6 described capacitor type power equipment dielectric loss on-line monitoring methods, it is characterized in that described resitstance voltage divider (3) is selected powerful resistance polyphone dividing potential drop for use, power is 4W.
7. the device of capacitor type power equipment dielectric loss on-line monitoring method as claimed in claim 2, it is characterized in that, the highest real-time sampling speed of described data collecting card is 20MS/s, analog bandwidth is 15MHz, 8 of A/D resolution, input voltage range-5V～+ 5V, and the two-way input end of analog signal is arranged.
8. the device of capacitor type power equipment dielectric loss on-line monitoring method as claimed in claim 2 is characterized in that described digital I has three ports, and 8 of each ports are formed a control word, writes control word and realize control function on each port.
CN 200420041921 2004-05-17 2004-05-17 Dielectric loss on-line monitoring device for capacitive electric equipment Expired - Fee Related CN2718591Y (en)

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Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102243264A (en) * 2010-04-13 2011-11-16 施耐德电器工业公司 Measurement device with an electric voltage divider
CN102401855A (en) * 2011-11-22 2012-04-04 李云宏 Electric digital instrument using Rogowski coil current transformer
CN102841245A (en) * 2012-09-24 2012-12-26 广西电网公司电力科学研究院 Device for detecting end screen current parameter of high-voltage transformer bushing in real time, and control method for device
CN103001096A (en) * 2012-08-22 2013-03-27 苏州久三智能科技有限公司 Wire sensing device
CN103412172A (en) * 2013-07-16 2013-11-27 国家电网公司 Multi-channel leakage current measurement system and measurement method
CN103630813A (en) * 2013-12-05 2014-03-12 国网上海市电力公司 Solid insulated conductor insulation electrified monitoring method
CN105301432A (en) * 2015-11-26 2016-02-03 国网山东省电力公司济南供电公司 Electric power equipment insulation leakage current on-line monitoring circuit
CN107271828A (en) * 2017-04-28 2017-10-20 国网山东省电力公司寿光市供电公司 Aerial lift device with insulating arm for live working leakage current warning device
CN109358270A (en) * 2018-08-22 2019-02-19 国网天津市电力公司电力科学研究院 A method of for assessing crosslinking polyethylene-insulated cable insulation ageing state
CN109884487A (en) * 2019-03-29 2019-06-14 国网河南省电力公司检修公司 A kind of capacitance type equipment insulation monitoring mobile device
CN110045251A (en) * 2019-05-05 2019-07-23 湖北工业大学 A kind of power cable built-in electrical insulation defects detection and failure detector and method
CN111768599A (en) * 2020-07-08 2020-10-13 安徽先兆科技有限公司 AC380V loop electric safety control method and system

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102243264A (en) * 2010-04-13 2011-11-16 施耐德电器工业公司 Measurement device with an electric voltage divider
CN102243264B (en) * 2010-04-13 2016-05-11 施耐德电器工业公司 With the measurement device of voltage divider
CN102401855A (en) * 2011-11-22 2012-04-04 李云宏 Electric digital instrument using Rogowski coil current transformer
CN103001096A (en) * 2012-08-22 2013-03-27 苏州久三智能科技有限公司 Wire sensing device
CN102841245A (en) * 2012-09-24 2012-12-26 广西电网公司电力科学研究院 Device for detecting end screen current parameter of high-voltage transformer bushing in real time, and control method for device
CN103412172A (en) * 2013-07-16 2013-11-27 国家电网公司 Multi-channel leakage current measurement system and measurement method
CN103630813B (en) * 2013-12-05 2016-08-31 国网上海市电力公司 A kind of method of solid insulation conductor insulation live monitoring
CN103630813A (en) * 2013-12-05 2014-03-12 国网上海市电力公司 Solid insulated conductor insulation electrified monitoring method
CN105301432A (en) * 2015-11-26 2016-02-03 国网山东省电力公司济南供电公司 Electric power equipment insulation leakage current on-line monitoring circuit
CN107271828A (en) * 2017-04-28 2017-10-20 国网山东省电力公司寿光市供电公司 Aerial lift device with insulating arm for live working leakage current warning device
CN107271828B (en) * 2017-04-28 2019-07-12 国网山东省电力公司寿光市供电公司 Aerial lift device with insulating arm for live working leakage current warning device
CN109358270A (en) * 2018-08-22 2019-02-19 国网天津市电力公司电力科学研究院 A method of for assessing crosslinking polyethylene-insulated cable insulation ageing state
CN109884487A (en) * 2019-03-29 2019-06-14 国网河南省电力公司检修公司 A kind of capacitance type equipment insulation monitoring mobile device
CN110045251A (en) * 2019-05-05 2019-07-23 湖北工业大学 A kind of power cable built-in electrical insulation defects detection and failure detector and method
CN111768599A (en) * 2020-07-08 2020-10-13 安徽先兆科技有限公司 AC380V loop electric safety control method and system

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