CN203405510U - Long-life digital transformer iron core grounding current monitoring device - Google Patents

Long-life digital transformer iron core grounding current monitoring device Download PDF

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Publication number
CN203405510U
CN203405510U CN201320545567.8U CN201320545567U CN203405510U CN 203405510 U CN203405510 U CN 203405510U CN 201320545567 U CN201320545567 U CN 201320545567U CN 203405510 U CN203405510 U CN 203405510U
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CN
China
Prior art keywords
current
module
iron core
long
transformer
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CN201320545567.8U
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Chinese (zh)
Inventor
李辉
陈江波
张曦
尹晶
蔡胜伟
郭慧浩
邵苠峰
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国家电网公司
中国电力科学研究院
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Priority to CN201320545567.8U priority Critical patent/CN203405510U/en
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Publication of CN203405510U publication Critical patent/CN203405510U/en

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Abstract

The utility model provides a long-life digital transformer iron core grounding current monitoring device. The device comprises a control module, a transformer and a current sensor. The current sensor is a Rogowski coil type current sensor disposed on the top of the side recess part of the transformer and used for measuring grounding currents of the iron core and an iron core clamp. The output end of the Rogowski coil type current sensor is successively connected with a current-limiting resistor switching module, a signal conditioning circuit, an analog-to-digital conversion module and a data transceiver module. The output end of the data transceiver module carries out remote signal transmission to a remote monitoring system. The output end of the control module is connected with the input end of the current-limiting resistor switching module. The device allows the iron core grounding current sensor to be internal and digital, achieves long service life of the sensor, directly converts a current analog quantity to be digital, utilizes fiber remote transmission to prevent signal attenuation and interference, enables remote switching of a current-limiting resistor to reduce iron core grounding current, gains time for transformer maintenance to prevent overlarge faults.

Description

A kind of long-life digital transformer iron core grounding current monitoring device
Technical field
The utility model relates to a kind of device of sensor technical field, specifically relates to a kind of long-life digital transformer iron core grounding current monitoring device.
Background technology
Power transformer is most important electrical equipment in electric system, once in service, breaks down, and will cause serious consequence to electric system.Iron core is the critical piece of transformer internal delivery, conversion electromagnetic energy, the necessary ground connection of transformer core of normal operation, and can only one point earth, if have or 2 above ground connection simultaneously at 2, between iron core and the earth, will form current return, maximum current can reach tens A, will cause local overheating unshakable in one's determination even to burn.
Normal operating transformer iron core is single-point grounding, and now flowing through electric current in iron core grounding line is electric capacity iron core being existed due to high pressure winding, low pressure winding; Transformer can be divided into single transformer and three-phase transformer; For three-phase transformer, when three-phase voltage full symmetric, flow through in theory iron core grounding line current and be zero, but measured current value generally at several mA between tens mA; For single transformer (as 500kV, 750kV grade transformer), because electric capacity between winding and iron core very little (general several thousand pF) impedance is very large, calculating and actual measurement show that this current value is also below tens mA; Once but iron core outlet multipoint earthing, now earth lead, body unshakable in one's determination, transformer case and the earth form closed-loop path, and the main flux in iron core and leakage flux will induce circulation in this closed-loop path, reach as high as tens A.The current value flowing through in ground wire when single-point grounding and multipoint earthing unshakable in one's determination differs larger, stipulates that this electric current is no more than 0.1A in national standard DL/T572 power transformer operating standard.
At present judge whether transformer core exists multipoint earthing to mainly contain three kinds of methods: the Electric Method of clamp on amperemeter periodic monitoring iron core grounding electric current, measure insulation against ground electric-resistivity method unshakable in one's determination, the gas chromatography of monitoring transformer insulation oil characteristic gas.
The deficiency that above method exists is to find in time multipoint earth faults unshakable in one's determination, once break down, can not take in time corresponding measure; In prior art, have external opening current sensor measurement iron core grounding electric current, but external sensor measures easy affected by environment and serviceable life is low, therefore, provides a kind of long-life digital transformer iron core grounding electric current on-Line Monitor Device particularly important.
Summary of the invention
For overcoming above-mentioned the deficiencies in the prior art, the utility model provides a kind of long-life digital transformer iron core grounding current monitoring device, this installs the built-in and digitizing by iron core grounding current sensor, realize the long lifetime of sensor, and by current analog amount Direct Digital, adopt fiber-optics remote transmission, avoid decay and the interference of signal, can realize long-range switching current-limiting resistance and reduce iron core grounding electric current, for Repair of Transformer, race against time, avoid fault excessive.
The solution of the utility model technical solution problem is:
A kind of long-life digital transformer iron core grounding current monitoring device, described device comprises control module, transformer and current sensor, its improvements are: described current sensor is the Luo-coil type current sensor of being located at transformer top or side-facing depressions place, measure the ground current of unshakable in one's determination and core clamping;
The output terminal of described Luo-coil type current sensor connects current-limiting resistance switching module, signal conditioning circuit, analog-to-digital conversion module and data transmit-receive module successively; The output terminal remote transmission signal of described data transmit-receive module is to long distance control system; The output terminal of described control module connects the input end of described current-limiting resistance switching module.
Further, the electric current that described Rogowski coil current sensor obtains converts digital quantity to through described signal conditioning circuit and described analog-to-digital conversion module, digital quantity is sent to described control module, and described control module is sent to respectively long distance control system and mobile device through described data transmit-receive module by optical fiber and wireless gsm module.
Further, the data that described control module is obtained according to described Luo-coil type current sensor are determined switching resistance value, and the control signal of switching resistance value is sent to described current-limiting resistance switching module.
Further, described current-limiting resistance switching module carries out current-limiting resistance switching according to the control signal of described switching resistance value, reduces ground current value.
Further, described data transmission blocks is connected with long distance control system and mobile device are two-way respectively by optical fiber and wireless gsm module.
Further, described tele-control system triggers the described current-limiting resistance switching module that controls signal to that described control module sends resistance switching value, drops into or excision resistance.
Further, described control module comprises CPU and Man Machine Interface.
Compare with existing monitoring device, the beneficial effect that the utility model reaches is:
1, the utility model is by built-in sensor design, and shielding outside electromagnetic interference and prolongation iron core grounding current monitoring, with the life-span of sensor, are carried out integrated design with transformer insulated and structure and strengthened reliability.
2, the utility model adopts analog to digital conversion conditioning device, by analog quantity in-situ digitalization, avoids the decay of analog quantity signal transmission and other electromagnetic fields to disturb analog quantity.
3, the utility model adopts optical fiber or wireless transmission, and digital information is realized to remote transmission by outdoor tension enhanced fiber, avoids decay and disturbs, and sending switching record value to operations staff by wireless gsm module, in time fault is reacted.
4, the long-range current-limiting resistance switching of the utility model, can realize the switching of current-limiting resistance by monitor screen, reduce in time ground current value, avoids overheated initiation transformer fault, for Repair of Transformer is striven for the optimistic time.
Accompanying drawing explanation
Fig. 1 is based on long-life digital transformer iron core grounding current monitoring device process flow diagram;
Fig. 2 is based on long-life digital transformer iron core grounding current monitoring device structural drawing;
Fig. 3 is the relay amount of outputing schematic diagram.
Embodiment
Below in conjunction with accompanying drawing, embodiment of the present utility model is described in further detail;
As shown in Figure 1, 2, Fig. 1 is based on long-life digital transformer iron core grounding current monitoring device process flow diagram and structural drawing; Based on long-life digital transformer iron core grounding current monitoring device, comprise transformer, built-in Luo-coil type current sensor, analog to digital conversion conditioning module, control module, current-limiting resistance switching module, data transmit-receive module and long distance control system, the iron core grounding line of this transformer, transformer top adopts inner recess formula that Luo-coil type current sensor is installed, and measures the ground current of iron core and/or core clamping; Or transformer side adopts inner recess formula that Luo-coil type current sensor, the ground current of measurement iron core and/or core clamping are installed; Analog to digital conversion conditioning module receives the data of described Luo-coil type current sensor, to control module, transmits described data, data through data transmission blocks by optical fiber or wireless module (GSM) remote transmission to long distance control system or mobile device.
Described iron core grounding current monitoring device and transformer adopting integrated design, described transformer adopting top or side inner recess formula transformer, do not changing on the basis of transformer inner structure, in transformer top or lateral recess, be used for installing Luo-coil type current sensor, transformer outer enclosure.
The current conversion that signal conditioning circuit obtains Rogowski coil current sensor with analog-to-digital conversion module becomes digital quantity, data are through fiber-optics remote transmission to long distance control system, and supervisory system is carried out sound and light alarm after Transformer Core Grounding electric current and core clamping electric current are exceeded standard.
Signal conditioning circuit comprises low-pass filtering and high-pass filtering circuit, for filtering interfering noise.
D/A converter module is for being converted to digital quantity by current signal.
Control module, the data acquisition switching resistance value according to receiving, sends control information to described current-limiting resistance switching module.Control module is by CPU(DSP TMS320LF2407), keyboard, liquid crystal display form, its function mainly realizes current digital collection, data storage, the calculating of switching resistance value, early warning value setting, user's input information etc.
Current-limiting resistance switching module, the warning of pointing out by long distance control system, carries out current-limiting resistance switching, reduces ground current value, for Repair of Transformer, races against time, and avoids occurring emergency.The switching of current-limiting resistance is realized by the relay of current-limiting resistance switching module, the driving circuit of relay triggers by the I/O pin of control module CPU, control module is calculated and is obtained switching resistance value, provide relay coil actuating signal and be sent to current-limiting resistance switching module, this relay coil actuating signal comprises the switching resistance value of answering switching, make relay conducting produce contactor coil and control electric current, drop into or excision resistance.
As shown in Figure 3, Fig. 3 is the relay amount of outputing demonstration figure, and the output current of the I/O pin of control module (comprising CPU, as DSP TMS320LF2407) can reach 20mA, can directly drive photoelectrical coupler work.Consider that general output execution may have large electric current, therefore need first through relay, drive, realize and isolate and drive gradually.When I/O port signal is 1, light emitting diode conducting, photoisolator work, the triode conducting in photoisolator, the not conducting of triode being connected with resistance, the coil of relay can not conducting, and relay is failure to actuate; Otherwise when I/O port is 0, the actuating of relay, provides driving signal.
Data transmission blocks, by optical fiber or wireless module remote transmission data to long distance control system.Long distance control system is carried out sound and light alarm after Transformer Core Grounding electric current is exceeded standard, and good interactive interface is provided, and facilitates operations staff to operate switching resistance, records switching resistance time and number of times, current change quantity before and after switching.
Long distance control system can arrange time of fire alarming, as surpassed this time of fire alarming, do not drop into current-limiting resistance, long distance control system will drop into current-limiting resistance automatically according to size of current, send a signal to current-limiting resistance switching module, detecting iron core grounding electric current is less than after setting 0.1A, cancelling reports to the police and provide drops into resistance value interface, and fault-time, fault current and input current-limiting resistance value are by sending to operations staff's mobile phone by wireless gsm module.
The present invention also provide a kind of to should install based on long-life digital transformer iron core grounding current monitoring method, the method comprises the following steps:
S01, starter gear, test.
S02, built-in Luo-coil type current sensor obtain current signal, send a signal to current-limiting resistance switching module.
S03, current signal, through short-circuit loop (now dropping into without the current-limiting resistance) transmitted signal of current-limiting resistance switching module, are digital quantity through signal conditioning circuit and analog-to-digital conversion module by current conversion, and are sent to control module.
S04, control module are calculated and are obtained the current-limiting resistance switching value of answering switching according to the data that receive, control module sends resistance switching value to current-limiting resistance switching module, carries out current-limiting resistance switching, reduces ground current value, for Repair of Transformer, race against time, avoid occurring emergency.Meanwhile, resistance switching value is transmitted through the fiber to long distance control system through data transmit-receive module, and by wireless gsm module, sends data to operations staff's communication facilities, as mobile phone.
Between S05, long distance control system and control module, by optical fiber communication, trigger control module sends switching instruction to resistive module.
Long distance control system arranges time of fire alarming, as surpassed this time of fire alarming, do not drop into current-limiting resistance, long distance control system will drop into current-limiting resistance according to size of current Lookup protocol, send a signal to control module, trigger control module sends resistance switching value to current-limiting resistance switching module, realizes Transformer Core Grounding electric current real time on-line monitoring.
Generally, detect iron core grounding electric current and be less than after setting 0.1A, cancelling reports to the police and provide drops into resistance value interface, and fault-time, fault current and input current-limiting resistance value are by sending to operations staff's mobile phone by wireless gsm module.
Finally should be noted that: above embodiment is only for illustrating the application's technical scheme but not restriction to its protection domain; although the application is had been described in detail with reference to above-described embodiment; those of ordinary skill in the field are to be understood that: those skilled in the art still can carry out all changes, revise or be equal to replacement to the embodiment of application after reading the application; these change, revise or be equal to replacement, within the claim protection domain all awaiting the reply in application.

Claims (7)

1. a long-life digital transformer iron core grounding current monitoring device, described device comprises control module, transformer and current sensor, it is characterized in that: described current sensor is the Luo-coil type current sensor of being located at transformer top or side-facing depressions place, measure the ground current of unshakable in one's determination and core clamping;
The output terminal of described Luo-coil type current sensor connects current-limiting resistance switching module, signal conditioning circuit, analog-to-digital conversion module and data transmit-receive module successively; The output terminal remote transmission signal of described data transmit-receive module is to long distance control system; The output terminal of described control module connects the input end of described current-limiting resistance switching module.
2. a kind of long-life digital transformer iron core grounding current monitoring device as claimed in claim 1, it is characterized in that: the electric current that described Rogowski coil current sensor obtains converts digital quantity to through described signal conditioning circuit and described analog-to-digital conversion module, digital quantity is sent to described control module, and described control module is sent to respectively long distance control system and mobile device through described data transmit-receive module by optical fiber and wireless gsm module.
3. a kind of long-life digital transformer iron core grounding current monitoring device as claimed in claim 1, it is characterized in that: the data that described control module is obtained according to described Luo-coil type current sensor are determined switching resistance value, and the control signal of switching resistance value is sent to described current-limiting resistance switching module.
4. a kind of long-life digital transformer iron core grounding current monitoring device as claimed in claim 3, is characterized in that: described current-limiting resistance switching module carries out current-limiting resistance switching according to the control signal of described switching resistance value, reduces ground current value.
5. a kind of long-life digital transformer iron core grounding current monitoring device as claimed in claim 1, is characterized in that: described data transmission blocks is connected with long distance control system and mobile device are two-way respectively by optical fiber and wireless gsm module.
6. a kind of long-life digital transformer iron core grounding current monitoring device as claimed in claim 1, it is characterized in that: described tele-control system triggers the described current-limiting resistance switching module that controls signal to that described control module sends resistance switching value, drop into or excision resistance.
7. a kind of long-life digital transformer iron core grounding current monitoring device as claimed in claim 1, is characterized in that: described control module comprises CPU and Man Machine Interface.
CN201320545567.8U 2013-09-03 2013-09-03 Long-life digital transformer iron core grounding current monitoring device CN203405510U (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201320545567.8U CN203405510U (en) 2013-09-03 2013-09-03 Long-life digital transformer iron core grounding current monitoring device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201320545567.8U CN203405510U (en) 2013-09-03 2013-09-03 Long-life digital transformer iron core grounding current monitoring device

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103852624A (en) * 2014-03-28 2014-06-11 国家电网公司 Hand-held convertor transformer core grounding current tester
CN106093690A (en) * 2016-08-11 2016-11-09 国网天津市电力公司 Utilize the iron core on-line monitoring system of thermo-electric generation supply source

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103852624A (en) * 2014-03-28 2014-06-11 国家电网公司 Hand-held convertor transformer core grounding current tester
CN106093690A (en) * 2016-08-11 2016-11-09 国网天津市电力公司 Utilize the iron core on-line monitoring system of thermo-electric generation supply source

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