CN105699753A - Online monitoring device for grounding current of transformer core - Google Patents

Online monitoring device for grounding current of transformer core Download PDF

Info

Publication number
CN105699753A
CN105699753A CN201610185999.0A CN201610185999A CN105699753A CN 105699753 A CN105699753 A CN 105699753A CN 201610185999 A CN201610185999 A CN 201610185999A CN 105699753 A CN105699753 A CN 105699753A
Authority
CN
China
Prior art keywords
current
module
signal
monitoring
transformer
Prior art date
Application number
CN201610185999.0A
Other languages
Chinese (zh)
Inventor
沈伟
徐友刚
梅凡
沈晓峰
王大成
张佳栋
许震欢
黄冀华
Original Assignee
国网上海市电力公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 国网上海市电力公司 filed Critical 国网上海市电力公司
Priority to CN201610185999.0A priority Critical patent/CN105699753A/en
Publication of CN105699753A publication Critical patent/CN105699753A/en

Links

Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01RMEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/25Arrangements for measuring currents or voltages or for indicating presence or sign thereof using digital measurement techniques
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01RMEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/50Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01RMEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/50Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
    • G01R31/62Testing of transformers

Abstract

The invention relates to an online monitoring device for grounding current of a transformer core. The online monitoring device comprises a monitoring device body and a straight-through current transformer. The monitoring device body comprises a totally closed electromagnetic interference preventing housing. The external surface of the totally closed electromagnetic interference preventing housing is provided with a liquid crystal display screen and a device state indicating lamp. The totally closed electromagnetic interference preventing housing is internally provided with a signal acquiring and processing module, a communication module and a display interface module. The signal acquiring and processing module comprises a signal conditioning module, a digital-to-analog conversion circuit and a microprocessor unit. The signal conditioning module comprises a signal conversion circuit, a filter circuit and a signal amplification circuit. According to the online monitoring device, the straight-through current transformer is utilized for acquiring a leakage current signal of a grounding line of the transformer core, and a plan that the totally closed electromagnetic interference preventing housing and the current transformer are separately arranged is utilized. The online monitoring device has advantages of accurate and reliable monitoring data, high outer interference resistance and high convenience in mounting and maintenance.

Description

Transformer iron core grounding current on-Line Monitor Device
Technical field
The present invention relates to a kind of power equipment checking for grounded current device, particularly to a kind of transformer iron core grounding current on-Line Monitor Device, belong to electric apparatus monitoring field。
Background technology
Along with user is more and more higher to the requirement of power supply reliability, the safe and stable operation of electrical network is also more and more important。Power transformer is electrical network " heart "。Guaranteeing the properly functioning of transformator, the sign of discovery accident early, thus rushing to repair targetedly, the various damage controls that accident is caused, to bottom line, are related to social synthesis's benefit and the economic benefit of power grid enterprises。Current country is greatly developing intelligent power network, and the on-line monitoring system of transformer core is to constitute ingredient important in intelligent power network, by the on-line monitoring to iron core grounding current, can accurately judge the working condition of iron core, safeguard in time before iron core breaks down thus shooting the arrow at the target, not only effectively raise the reliability of power supply, also reduce the operating cost of power system as much as possible, the safe operation tool ensureing power transformer is of great significance。Therefore, we should strengthen multipoint earthing of iron core of transformer fault detect。Try hard to be timely discovery, process in time, to guarantee the safe and reliable operation of transformator, prevent the generation of transformer core fault to greatest extent。
When power transformer is properly functioning, electric field around winding, can be produced, and the metals such as unshakable in one's determination and folder are in electric field, if iron core does not have reliable ground, above will continuous stored charge, when reaching to a certain degree, electric discharge phenomena will be produced, damage and insulate。Therefore, the iron core of transformator must have some reliable grounds, if owing to some reason or fault, creates more than one earth point, then can form the closed-loop path of short circuit in iron core, and ground lead will produce circulation。On the one hand, causing partial short-circuit heating unshakable in one's determination, ground strip fuses, and even burns out iron core, and insulating oil decomposes;On the other hand, transformator hot-spot is caused, it is possible to create discharging fault。In running, in order to judge whether iron core exists multipoint earth faults, it is possible to judge by measuring the electric current in external ground wire unshakable in one's determination。At present, adopting unified heavy caliber clamp on amperemeter, being regularly on the scene carries out manual measurement。Such metering system has the disadvantage that: first, it is necessary to manual site measures, and requires great effort time-consuming, when running into fault, can delay certain emergency repair time。Second, in measurement process, it is inconvenient that steel core current measured by the little transformator of safe distance, and same measures point it sometimes appear that measurement data is different several times situation。3rd, the change of shape (current down conductor has flat copper line and circle) not adapting to iron core grounding downlead of clamp on amperemeter, so can cause data inaccurate and unstable。It addition, existing monitoring current device also faces the interference factor of various outside in actual use, and it is also inconvenient to install maintenance。
Summary of the invention
Transformer iron core grounding current on-Line Monitor Device of the present invention discloses new scheme, straight-through current transformer is adopted to gather leakage current signal, adopt the separately positioned scheme of the monitoring device body and the housing extrinsic current transformer that are arranged in totally-enclosed anti-electromagnetic interference shell guarantee the precision of monitoring measurement device data and accuracy and find fault in time basis on enhance monitoring device and adapt to the ability of outside severe running environment, improve the convenience installing maintenance that device is overall, solve existing monitoring device poor anti jamming capability, install and safeguard inconvenient problem。
Transformer iron core grounding current on-Line Monitor Device of the present invention includes monitoring device body and straight-through current transformer, the collection terminal of straight-through current transformer electrically connects with transformer core grounding line, the outfan of straight-through current transformer electrically connects with monitoring device body, monitoring device body includes totally-enclosed anti-electromagnetic interference shell, totally-enclosed anti-electromagnetic interference hull outside surface is provided with LCDs and unit state display lamp, it is provided with Signal acquiring and processing module in totally-enclosed anti-electromagnetic interference shell, communication module and display interface module, Signal acquiring and processing module includes Signal-regulated kinase, D/A converting circuit and microprocessor unit, Signal-regulated kinase includes signaling conversion circuit, filter circuit and signal amplification circuit, iron core grounding current signal is sent to microprocessor unit by straight-through current transformer outfan after Signal-regulated kinase and D/A converting circuit process, the signal received is sent to communication module and/or display interface module by microprocessor unit after digital filtering and computing, the signal received is sent out detecting device by communication module after treatment, the signal received is sent to display interface module LCDs after treatment and unit state display lamp illustrates。
Transformer iron core grounding current on-Line Monitor Device of the present invention adopts straight-through current transformer to gather transformer core grounding line leakage current signal, adopt the scheme of totally-enclosed anti-interference monitoring device body and current transformer split design, there is Monitoring Data accurately and reliably, the feature that anti-external disturbance ability is strong and convenient for installation and maintenance。
Accompanying drawing explanation
Fig. 1 is that the present invention monitors device mounting structure schematic diagram。
Fig. 2 is that the present invention monitors device operation principle schematic diagram。
Fig. 3 is the current-limiting resistance electrical schematic diagram that current-limiting resistance throws cutting control device。
In Fig. 1,110 is totally-enclosed anti-electromagnetic interference shell, and 200 is straight-through current transformer。The positive basifacial of totally-enclosed anti-electromagnetic interference shell in Fig. 1 adopts broken section mode to show its internal circuit module installation site, wherein, pcb board is provided with SIM card slot, MINIUSB slot, current transformer slot, AC220V power interface and RS485 COM1。
Detailed description of the invention
Below in conjunction with accompanying drawing, the invention will be further described。
As it is shown in figure 1, transformer iron core grounding current on-Line Monitor Device schematic diagram of the present invention。Transformer iron core grounding current on-Line Monitor Device includes monitoring device body and straight-through current transformer, the collection terminal of straight-through current transformer electrically connects with transformer core grounding line, the outfan of straight-through current transformer electrically connects with monitoring device body, monitoring device body includes totally-enclosed anti-electromagnetic interference shell, totally-enclosed anti-electromagnetic interference hull outside surface is provided with LCDs and unit state display lamp, it is provided with Signal acquiring and processing module in totally-enclosed anti-electromagnetic interference shell, communication module and display interface module, Signal acquiring and processing module includes Signal-regulated kinase, D/A converting circuit and microprocessor unit, Signal-regulated kinase includes signaling conversion circuit, filter circuit and signal amplification circuit。Fig. 1 illustrates the totally-enclosed anti-electromagnetic interference shell that this programme adopts, and has the function of good anticorrosion, Radix Saposhnikoviae, dust-proof and anti-electromagnetic interference, it is possible to provide good running environment to internal electrical equipment, it is to avoid it is subject to the impact of outside adverse circumstances。Fig. 1 also show the monitoring device body of this programme employing and designs a model with current transformer split, this design effectively improves the environment of each electrical equipment independent operating, makes monitoring device body can choose suitable installation site flexibly according to field condition simultaneously。In order to improve the security performance of straight-through current transformer itself; the straight-through current transformer of this programme is located in the alloy shell of closing; straight-through current transformer outfan is provided with overvoltage protector, and straight-through current transformer outfan is electrically connected with monitoring device body by screened cable。The security protection scheme that such scheme is addressed improves the overall running quality of monitoring device and efficiency, creates good effect in actual applications。
When a failure occurs, the earth point of transformer core is by a bit increasing to two or more, the electric current flowing through iron core will sharply increase people, transformer core will be caused serious harm as got rid of not in time, at this moment need to overhaul to fix a breakdown to transformator, but the maintenance of transformator is by power supply plan, the impact of the factors such as repair schedule and cannot carry out immediately, in this case, it is generally adopted serial resistance to reduce earth current value, operation and maintainer reason and the order of severity to fault if having time is made to be estimated, if really needing maintenance down, can in the Dispatching adjustment equipment method of operation, standby redundancy prepares and man of transformer factory personnel make equipment be in running status before factory, reduce the loss brought to electrical network and user that has a power failure, improve power supply reliability。Above scheme specifically transformer iron core grounding current on-Line Monitor Device also includes current-limiting resistance and throws cutting control device, current-limiting resistance is thrown cutting control device and is included current-limiting resistance switching control module and current-limiting resistance circuit, current-limiting resistance circuit includes the current-limiting resistance of one group of series connection, the current-limiting resistance upstream circuitry of above-mentioned one group of series connection is provided with group and accesses switch, in the current-limiting resistance of above-mentioned one group of series connection, the two of each current-limiting resistance are terminated with being tapped into switch, current-limiting resistance switching controls module and is connected with microprocessor unit signal, current-limiting resistance switching controls module and accesses switch according to the current limliting instruction progressively unlatching group successively received, it is tapped into switch and current-limiting resistance is accessed circuit, specifically automatically put into current-limiting resistance to reduce earth current as emergency measure by gear when electric current exceedes setting limit value, automatically current-limiting resistance is excised when electric current is lower than limit value。Fig. 3 illustrates a kind of implementation that the current-limiting resistance circuit of this programme can adopt, and in figure, K, K1, K2, K3 are four normally closed reverse-blocking tetrode thyristors, by CPU by Control folding, when iron core generation multipoint earthing, CPU sends corresponding actuating signal to each relay, is first opened by K, then opens switch K1, current-limiting resistance R1 is made to access, then testing current value, if going back backlog demand, then K2 being opened, by that analogy, until the size of earth current meets the requirement operated with failure。
In order to meet power equipment actual requirement of sustainable normal operation in various complicated rugged environments, in device powers down and the running status suffering various external disturbance to adjust equipment abnormal operating condition occurs in time, save the service data because of fault loss or distortion, this programme can also set up corresponding intelligent object to realize above-mentioned functions, specifically monitoring device body also includes internal non-volatile memory module, internal non-volatile memory module power-off standby system data, when there is short time disconnection fault in equipment, in internal non-volatile memory module, before the power-off of storage, normal data can provide Data Source for the data transmission after restoring electricity and processing。Therefore, monitoring device body also includes data diagnosis and recovers module, device is returned to normal condition after sending alarm signal according to the abnormal signal that monitoring obtains by data diagnosis and recovery module, and required data can be transferred in above-mentioned internal non-volatile memory module。Circuit, module and the electronic devices and components that above is referred to all can adopt scheme generally in the art, it is also possible to adopts specially designed scheme according to actual needs。
Iron core grounding current signal is sent to microprocessor unit by the straight-through current transformer outfan of this programme after Signal-regulated kinase and D/A converting circuit process, the signal received is sent to communication module and/or display interface module by microprocessor unit after digital filtering and computing, the signal received is sent out detecting device by communication module after treatment, and the signal received is sent to display interface module LCDs after treatment and unit state display lamp illustrates。So that such scheme realizes high-effect operation, the operational effect that enhancing system is overall, each vitals of system is also optimized type selecting by this programme, specifically LCDs adopts 5 Digital sum pipe display real-time earthing current values, and Signal acquiring and processing module adopts the NCP1117ST33T3G power supply chip of STM32F405RGT6 controller, C8051F005 single-chip microcomputer, AD7606BSTZ modulus conversion chip, AD8512ARZ amplifier chip, MC74HC595ADR2G shift register chip and STO-223 encapsulation。
Controller is the core of whole TT&C system, its main task be the digital independent of completion system calculate, the coordination of each circuit and management, process man-machine interface control, output switch parameter control and with the communication etc. of field monitoring equipment。The controller model that this device is selected is STM32F405RGT6。STM32F405RGT6 controller is based on a controller of high-performance ARMCortex-M432 position kernel, can run under the frequency up to 168MHz。This kernel adopts floating point unit single precision, supports all ARM single precision data processing instructions and data type。It also achieves DSP instruction and the internal memory protected location of complete set, thus improving the safety of application program。STM32F405RGT6 controller adopts high speed in-line memory, and flash memory is up to 1M byte, the SRAM of up to 192 bytes, the backup SRAM of maximum 4KB, and is connected to two enhancement mode I/O and peripheral hardware APB bus, ahb bus and ahb bus matrixes more than 32 widely。STM32F405RGT6 controller has 3 12 ADC, two DAC, low-power consumption RTC, 12 general 16 bit timing devices, and including two PWM intervalometers, motor controls, 2 general 32 bit timing devices。True Random Number Generator。Further provided with standard and high level communication interface。The operating temperature range of STM32F405RGT6 controller is-40 DEG C to 105 DEG C, it is possible to the power supply to 1.8 to 3.6V is powered。A set of comprehensive battery saving mode allows low power dissipation design application program。Therefore, this device adopts C8051F005 single-chip microcomputer to fully meet performance and designing requirement as the controller of iron core grounding current on-Line Monitor Device。
According to actual device requirements of one's work, have chosen the AD7606BSTZ functional chip as analog digital conversion。This chip is 16, multi-channel synchronal sampling modulus data acquisition system (DAS)。Device built-in analog input clamping protection, second order frequency overlapped-resistable filter, follow the tracks of hold amplifier, 16 Charge scaling SAR ADC, flexibly digital filter, 2.5V reference voltage source, reference voltage buffering and high speed serialization and parallel interface。This chip adopts 5V single supply to power, it is possible to process ± 10V and the ± true bipolar input signal of 5V, all passages all can be sampled with the throughput rate of up to 200kSPS simultaneously。Input clamp protection circuits can tolerate and be up to ± the voltage of 16.5V。No matter with which kind of sample frequency working, the simulation input impedance of AD7606BSTZ is 1M Ω。It adopts single supply working method, has filtering and high input impedance in sheet, therefore without driving operational amplifier and outside bipolar power supply。The 3dB cut-off frequency of AD7606BSTZ frequency overlapped-resistable filter is 22kHz, and when sampling rate is 200ksps, it has the anti-aliasing rejection characteristic of 40dB。Digital filter adopts pin to drive flexibly, it is possible to improves signal to noise ratio (SNR), and reduces three dB bandwidth。
The amplifier chip selected in this covering device is AD8512ARZ。It is a two-way precision JFET amplifier, has low maladjustment voltage, low input bias current, low input noise and low input current noise characteristic。Low imbalance, low noise and these characteristics of extremely low input bias current combine so that it is be particularly suitable for high impedance sensor and amplify and adopt the precision current of shunting to measure。DC precision, low noise and quickly set up time response and combine, then make Medical Instruments, electronic surveying and ATE can obtain the precision of excellence。Even if capacitive load is quite big, AD8512ARZ also can keep quickly setting up performance。Being different from many old-fashioned JFET amplifiers, when input voltage exceedes maximum common mode voltage scope, AD8512ARZ will not occur output anti-phase。AD8512ARZ still provides quick slew rate and superregulated property under capacitive load, is therefore especially suitable for high performance filter and uses。Low input bias current, low imbalance and low-noise characteristic make photo diode amplifier circuit have wider dynamic range。Low noise, low distortion, High Output Current and outstanding speed make AD8512ARZ become the excellent selection of voice applications。
MC74HC595ADR2G is a high speed Si-gate COMS device, and compatible with low voltage Schottky TTL (LSTTL)。They meet JEDEC7A file standard。MC74HC595ADR2G is 8 Bits Serial and the shift register with memory register and ternary output, memory register and shift register are synchronized with different clocks。Data move under the positive transition of shift register clock (SHCP), and under the positive transition of memory register clock (STCP), data are dumped to memory register by shift register。If SHCP and STCP is coupled together, shift register will always be ahead of one clock pulses of memory register。Shift register has a serial input terminal, also has a serial output terminal for cascade。8 bit shift register can asynchronous reset (low level reset)。Memory register has 8 tri-state parallel output terminals。When output Enable Pin (effectively low) data that are enabled will export to device pin from memory register。Therefore, MC74HC595ADR2G has the following characteristics that (1) 8 Bits Serial input;(2) 8 Bits Serial or parallel output;(3) the memory register of ternary output;(4) shift register directly empties;(5) 100MHz (representative value) shifts output frequency;(6) HBM (anthropometric dummy) more than JESD22A114F2KV;(7) MM (machine model) more than JESDA115A0.2KV;(8) multiple encapsulation;(9)-40 DEG C~+80 DEG C ,-40 DEG C~+125 DEG C different temperatures grades。
The power supply chip that this covering device is selected has NCP1117ST33T3G, MC78M08BDTG, MC78M05BDTG, MC79M08BDTG。NCP1117ST33T3G is a kind of low voltage difference positive voltage regulators, and it can provide the output electric current more than 1A, and under the working environment beyond room temperature, when exporting the electric current of 800mA, maximum voltage drop only has 1.2V。It can provide 8 voltage stabilizing values, and does not have minimum load requirement, to keep voltage stabilizing。This device also comprises voltage adjustable module from 1.25V to 18.8V, utilizes two non-essential resistances to realize the adjustment to voltage。Internal protection characteristic includes output electric current restriction, and safety operation area compensates and Thermal shutdown。This device adopts STO-223 encapsulation。
The communication module of this programme can adopt wired and wireless two kinds of communication patterns, utilize radio communication technology, staff can pass through the mode of backstage or SMS and regularly or understand the numerical value inquiring about core current in real time, it is also possible to independently the notes such as the cycle of transmission data and early warning and alarming value is set a property flexibly by note and modifies。Specific as follows。
(1) communication module includes RS485 communication interface, and the signal received is sent out monitoring device by RS485 communication interface by communication module after treatment。
(2) communication module includes CAN communication interface, and the signal received is sent out monitoring device by CAN communication interface by communication module after treatment。
(3) communication module includes gsm communication interface, and totally-enclosed anti-electromagnetic interference hull outside surface is additionally provided with GSM antenna, and the signal received is sent out monitoring device by gsm communication interface by communication module after treatment。
GSM (GlobalSystemforMobileCommunications) communication is as a kind of core network of mobile communication, and through development for many years, GSM mobile public network has become as a kind of communication resource being most widely used in society。GSM message breath service SMS (shortMessageService) is as a kind of basic service of GSM network, it it is the simplest and convenient data communication method, run highly developed stable, with low cost, have been introduced into every field, become enterprise and a part for sector application interwoveness。First this project will support GSM message function, when earth current more sends a warning message to operation maintenance personnel in limited time。
(4) communication module includes GPRS communication interface, and the signal received is sent out monitoring device by GPRS communication interface by communication module after treatment。
The abbreviation of GPRS (GeneralPacketRadioService) general packet radio service technology, is the continuity of GSM。GPRS, with in the past different in the mode of channel transmission continuously, transmits with package (Packet) formula, it is possible to by using charge on traffic, expense is relatively low, and transfer rate is up to 56Kbps even 114Kbps。Can as the support technology of monitoring in real time, inquiry。
In actual environment, the electromagnetic environment that transformator runs is very severe, and iron core grounding current signal is easy to be submerged in powerful electromagnetic interference, and therefore monitoring systematic function does not often reach and meet practical requirement。Therefore, effectively suppressing interference, accurately acquisition earth current information is one of key technology of core insulation on-line checking。If anti-interference problem solves bad, then how superior also of no avail other index (such as precision etc.) of system is again。Electromagnetic interference can pass through various circuit intrusion systems, it is also possible to by the form of electromagnetic field directly from external disturbance system。For this reason, it may be necessary to take measures from hardware and software two aspect, improve the capacity of resisting disturbance of device。The overvoltage simultaneously brought to bear power system frequent operation is impacted; device have also been devised reliable surge protection circuit; current signal is gathered the interface such as measuring circuit and power circuit and has carried out the design of excess voltage protection, effectively raise the protective capability of monitoring device antisurge。By various effective measures, enhance capacity of resisting disturbance and the reliability of device。Specific as follows。
(1) Sensor section
1) punching leakage current sensor precision is high, and the capacity of resisting disturbance of self is very strong。
2) use the alloy shell closed, shield external electromagnetic interference。
3) by with metal-shielded wire, reliably realizing effective grounding。
4) by adding overvoltage protector at sensor output, it is ensured that the steady state voltage of outfan。
5) screened cable (suppression differential mode interference) is adopted。
6) output voltage and the signal to noise ratio of sensor are improved。
(2) PCB design part
1) by dividing respective region, analog circuit and digital circuit is allowed to be separated from each other。
2) ground configurations space, particularly earth lead have been stayed。
3) beeline line。
Power supply, design of Grounding Connections
1) design of Grounding Connections: be configured to wire grid。
2) Power Management Design: analog circuit, digital circuit are each independently-powered。
3) product design of Grounding Connections: digital circuit, analog circuit and high-power switching circuit have independent ground wire and ground wire exit on main circuit board。
(4) wires design
1) the holding wire vertical wirings of adjacent layer is in case thousand disturbing between stop signal line。
2) for reducing grounding wire impedance, power and ground is widened。
3) for reducing noise resistance, holding wire is close proximity to ground wire。
4) ground wire is tried one's best overstriking, notes thinner ground wire。
(5) Software Anti-interference
1) instruction redundancy method: inserting several non-operation instruction in every section of program, protection subsequent instructions can completely be performed。
2) software falls into wording: utilize untapped dummy cell to go jump instruction to fill up, and sets up and becomes software " fall into and say ", forces and the program of crawl is pointed to certain specific address, so that system recovery is properly functioning。
3) Soft-Watchdog Technology for Each (WATCHDOG) method: if system be disturbed and out of control reach the regular hour after, produce spill over, make system reset thus automatically recovering properly functioning。
4) definitely redirect method: use absolute jump instruction, make each transfer branch all can return to display program。
Above scheme all can be realized by supporting system, electrical equipment, circuit, module and the electronic devices and components being directed to can select scheme generally in the art according to concrete being actually needed when not having specifically mentioned, specially designed scheme can also be adopted as required, to realize corresponding function。
The transformer iron core grounding current on-Line Monitor Device of this programme adopts the Digital Signal Processing of special current transformer, high-precision analog circuit and advanced person, measure wide ranges (1mA~30A), precision high (± 1%), good in anti-interference performance, Monitoring Data is accurately and reliably。Adopt multiple communication interface, configurable access electrical equipment comprehensive monitor system, it is possible to separate configurations is realize monitoring by GSM message, and application configuration is flexible。Adopt the scheme of device body and current transformer split design, special fixture makes current transformer can be flexibly mounted on iron core grounding downlead, device body can be flexibly mounted to diverse location according to field condition, and device possesses perfect self-checking function, can the state of judgment means alerting in time, have when not affecting transformator and running and all parts included the feature that sensor (bypass iron core grounding downlead) is installed and safeguarded。Adopt straight-through current transformer, do not destroy down conductor, the safe operation of transformator is had no effect, all elements all adopt industrialized standard to produce, having good anti-electromagnetic impact and temperature jump ability, device adopts hermetically sealed design, possesses the functions such as anticorrosion, Radix Saposhnikoviae, dust-proof, anti-electromagnetic interference, adapt to outdoor severe running environment, there is safe and reliable feature。Based on above feature, the transformer iron core grounding current on-Line Monitor Device of this programme is compared existing monitoring device and is possessed prominent substantive distinguishing features and significant progressive。
The transformer iron core grounding current on-Line Monitor Device of this programme is not limited to the content disclosed in detailed description of the invention, the technical scheme occurred in embodiment can individualism, can also mutually comprising, those skilled in the art fall within the scope of this programme according to this programme in conjunction with the simple alternative that known general knowledge is made。

Claims (10)

1. transformer iron core grounding current on-Line Monitor Device, it is characterized in that including monitoring device body and straight-through current transformer, the collection terminal of described straight-through current transformer electrically connects with transformer core grounding line, the outfan of described straight-through current transformer electrically connects with described monitoring device body, described monitoring device body includes totally-enclosed anti-electromagnetic interference shell, described totally-enclosed anti-electromagnetic interference hull outside surface is provided with LCDs and unit state display lamp, it is provided with Signal acquiring and processing module in described totally-enclosed anti-electromagnetic interference shell, communication module and display interface module, described Signal acquiring and processing module includes Signal-regulated kinase, D/A converting circuit and microprocessor unit, described Signal-regulated kinase includes signaling conversion circuit, filter circuit and signal amplification circuit, iron core grounding current signal is sent to described microprocessor unit by described straight-through current transformer outfan after described Signal-regulated kinase and D/A converting circuit process, the signal received is sent to described communication module and/or described display interface module by described microprocessor unit after digital filtering and computing, the signal received is sent out detecting device by described communication module after treatment, the signal received is sent to described display interface module described LCDs after treatment and unit state display lamp illustrates。
2. transformer iron core grounding current on-Line Monitor Device according to claim 1, it is characterized in that, described transformer iron core grounding current on-Line Monitor Device also includes current-limiting resistance and throws cutting control device, described current-limiting resistance is thrown cutting control device and is included current-limiting resistance switching control module and current-limiting resistance circuit, described current-limiting resistance circuit includes the current-limiting resistance of one group of series connection, the current-limiting resistance upstream circuitry of described one group of series connection is provided with group and accesses switch, in the current-limiting resistance of described one group of series connection, the two of each current-limiting resistance are terminated with being tapped into switch, described current-limiting resistance switching controls module and is connected with described microprocessor unit signal, described current-limiting resistance switching controls module and progressively opens described group of access switch successively according to the current limliting instruction received, it is tapped into switch and current-limiting resistance is accessed circuit。
3. transformer iron core grounding current on-Line Monitor Device according to claim 1 and 2; it is characterized in that; described straight-through current transformer is located in the alloy shell of closing; described straight-through current transformer outfan is provided with overvoltage protector, and described straight-through current transformer outfan is electrically connected with described monitoring device body by screened cable。
4. transformer iron core grounding current on-Line Monitor Device according to claim 1 and 2, it is characterised in that described monitoring device body also includes internal non-volatile memory module, described internal non-volatile memory module power-off standby system data。
5. transformer iron core grounding current on-Line Monitor Device according to claim 4, it is characterized in that, described monitoring device body also includes data diagnosis and recovers module, and device is returned to normal condition after sending alarm signal according to the abnormal signal that monitoring obtains by described data diagnosis and recovery module。
6. transformer iron core grounding current on-Line Monitor Device according to claim 1 and 2, it is characterized in that, described communication module includes RS485 communication interface, and the signal received is sent out monitoring device by described RS485 communication interface by described communication module after treatment。
7. transformer iron core grounding current on-Line Monitor Device according to claim 1 and 2, it is characterized in that, described communication module includes CAN communication interface, and the signal received is sent out monitoring device by described CAN communication interface by described communication module after treatment。
8. transformer iron core grounding current on-Line Monitor Device according to claim 1 and 2, it is characterized in that, described communication module includes gsm communication interface, being additionally provided with GSM antenna on described totally-enclosed anti-electromagnetic interference hull outside surface, the signal received is sent out monitoring device by described gsm communication interface by described communication module after treatment。
9. transformer iron core grounding current on-Line Monitor Device according to claim 1 and 2, it is characterized in that, described communication module includes GPRS communication interface, and the signal received is sent out monitoring device by described GPRS communication interface by described communication module after treatment。
10. transformer iron core grounding current on-Line Monitor Device according to claim 1 and 2, it is characterized in that, described LCDs adopts 5 Digital sum pipe display real-time earthing current values, and described Signal acquiring and processing module adopts the NCP1117ST33T3G power supply chip of STM32F405RGT6 controller, C8051F005 single-chip microcomputer, AD7606BSTZ modulus conversion chip, AD8512ARZ amplifier chip, MC74HC595ADR2G shift register chip and STO-223 encapsulation。
CN201610185999.0A 2016-03-29 2016-03-29 Online monitoring device for grounding current of transformer core CN105699753A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201610185999.0A CN105699753A (en) 2016-03-29 2016-03-29 Online monitoring device for grounding current of transformer core

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201610185999.0A CN105699753A (en) 2016-03-29 2016-03-29 Online monitoring device for grounding current of transformer core

Publications (1)

Publication Number Publication Date
CN105699753A true CN105699753A (en) 2016-06-22

Family

ID=56233036

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201610185999.0A CN105699753A (en) 2016-03-29 2016-03-29 Online monitoring device for grounding current of transformer core

Country Status (1)

Country Link
CN (1) CN105699753A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107764325A (en) * 2017-10-13 2018-03-06 南京力通达电气技术有限公司 A kind of transformer wall-hanging comprehensive on-line monitoring apparatus
CN109374949A (en) * 2018-10-10 2019-02-22 哈尔滨理工大学 Current detecting system
CN109581038A (en) * 2018-11-27 2019-04-05 国家电网有限公司 Electric power plug socket lightning protection control method, system and slave computer
CN110632376A (en) * 2019-09-27 2019-12-31 上海锐开电气有限公司 Iron core and folder ground current monitoring devices based on transformer copper bar ground connection

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN201654160U (en) * 2010-04-07 2010-11-24 北京光耀电力自动化有限公司 Transformer core grounding AC-DC on-line monitoring device
CN102411084A (en) * 2011-07-26 2012-04-11 东北电力科学研究院有限公司 Online monitoring device and method of grounding current of iron core of transformer
CN202217010U (en) * 2011-07-26 2012-05-09 东北电力科学研究院有限公司 Online monitoring device of grounding current of transformer iron core
CN103163364A (en) * 2013-03-21 2013-06-19 辽宁省电力有限公司电力科学研究院 Wireless monitoring device and monitoring method for grounding current of transformer core/clamp
CN203606424U (en) * 2013-10-21 2014-05-21 宁波理工智能电网技术有限公司 On-line monitoring device for grounding current of transformer core
CN204575735U (en) * 2015-04-09 2015-08-19 长沙市蓝虹电气技术有限公司 A kind of ground current monitoring device and outdoor current monitoring system
CN205450103U (en) * 2016-03-29 2016-08-10 国网上海市电力公司 On -line monitoring device for grounding current of transformer iron core

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN201654160U (en) * 2010-04-07 2010-11-24 北京光耀电力自动化有限公司 Transformer core grounding AC-DC on-line monitoring device
CN102411084A (en) * 2011-07-26 2012-04-11 东北电力科学研究院有限公司 Online monitoring device and method of grounding current of iron core of transformer
CN202217010U (en) * 2011-07-26 2012-05-09 东北电力科学研究院有限公司 Online monitoring device of grounding current of transformer iron core
CN103163364A (en) * 2013-03-21 2013-06-19 辽宁省电力有限公司电力科学研究院 Wireless monitoring device and monitoring method for grounding current of transformer core/clamp
CN203606424U (en) * 2013-10-21 2014-05-21 宁波理工智能电网技术有限公司 On-line monitoring device for grounding current of transformer core
CN204575735U (en) * 2015-04-09 2015-08-19 长沙市蓝虹电气技术有限公司 A kind of ground current monitoring device and outdoor current monitoring system
CN205450103U (en) * 2016-03-29 2016-08-10 国网上海市电力公司 On -line monitoring device for grounding current of transformer iron core

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107764325A (en) * 2017-10-13 2018-03-06 南京力通达电气技术有限公司 A kind of transformer wall-hanging comprehensive on-line monitoring apparatus
CN109374949A (en) * 2018-10-10 2019-02-22 哈尔滨理工大学 Current detecting system
CN109581038A (en) * 2018-11-27 2019-04-05 国家电网有限公司 Electric power plug socket lightning protection control method, system and slave computer
CN110632376A (en) * 2019-09-27 2019-12-31 上海锐开电气有限公司 Iron core and folder ground current monitoring devices based on transformer copper bar ground connection

Similar Documents

Publication Publication Date Title
Key Diagnosing power quality-related computer problems
CN201637791U (en) Online monitoring system for high-voltage shunt capacitor
CN205544597U (en) Multi -functional three -phase power monitoring device
CN201742158U (en) Online monitoring device for power transformer
CN101738565B (en) Adaptive fault indicator
CN101860076B (en) Electric energy quality monitoring and analyzing system
CN2729740Y (en) Apparatus for detecting grounding fault of electric distribution network
CN101030711B (en) Microcomputer protecting controller
CN101325331B (en) Method for implementing element for measuring distance between phases without relevance to load current and ground resistance
CN204389611U (en) Based on the power capacitor on-Line Monitor Device of ARM
CN101666851B (en) Insulation, voltage, grounding test and grounding finding device and use method thereof
CN202041575U (en) Condition monitoring system for zinc oxide lightning arrester
CN203422438U (en) Real-time monitoring and fault location system for overhead lines of power distribution network
CN205610355U (en) Intermediate protects on -line monitoring device based on loRa communication technology
CN106771870A (en) A kind of distribution net work earthing fault localization method and system
CN203690938U (en) Low-voltage reactive-power automatic compensation device
CN203084097U (en) On-line zinc oxide lightning arrester state monitoring device
CN102184625B (en) Third generation (3G) communication network-based transmission line fault area positioning system
CN101127456A (en) Intelligent management system for transformer substation assisted devices
CN203312781U (en) Integrated anti-islanding protection system for distributed power generation
CN204243896U (en) For the on off state monitoring device of power distribution network
CN201583603U (en) Switch cabinet electricity testing lightning arrester on-line monitoring device
CN102998511A (en) Discharge current monitoring device of lightning arrester
CN201611384U (en) Motor status monitoring and failure diagnosis system
CN103779967B (en) For TT&C system and the observing and controlling module thereof of distribution power automation terminal

Legal Events

Date Code Title Description
PB01 Publication
C06 Publication
SE01 Entry into force of request for substantive examination
C10 Entry into substantive examination
WD01 Invention patent application deemed withdrawn after publication

Application publication date: 20160622

WD01 Invention patent application deemed withdrawn after publication