500kV terminal box of transformer substation checking for grounded current platformsTechnical field
The utility model is related to a kind of substation grounding current sensing means more particularly to a kind of 500kV substation PTs endsSub- case N-terminal checking for grounded current platform.
Background technology
The 500kV substations of existing many main wiring modes, protection, metering, measurement are all from circuit PT with voltage.The ends PTSub- case N-terminal is connected to breakdown fuse over the ground, when primary side overvoltage, to prevent from scurrying into secondary side, injures equipment and the safety of personnel,Overvoltage punctures breakdown fuse, is spewed out into the earth rapidly.Breakdown fuse can not self-healing, will be with whole station after breakdownUnique one group of PT terminal box forms a circuit, causes two points ground fault.After breakdown fuse is breakdown, due to not believing accuratelyIt number determines specific fault point, searches extremely difficult.
Currently, the usual detection means of Field Force is surveyed using clamp on amperemeter under the ground connection of iron core grounded by outer lead casingWire current, this method is easily by strong electromagnetic environmental disturbances, it may appear that same measurement point not totally different feelings of homogeneous measured value differenceCondition, and cannot be guaranteed to find that iron core two points ground fault, accuracy of detection and timeliness all there is a problem of certain in first time；WaveManpower and materials are taken, certain unwatched substations have not been accomplished to measure in real time, there are security risks.Thus cannot be rightPT terminal box earth current situations make comprehensive, accurate judgement.
Utility model content
In order to overcome defect described above, the utility model to provide a kind of 500kV terminal box of transformer substation checking for grounded currentPlatform, in real time monitoring find out rapidly puncture place, to determine fault point, make corresponding counter-measure to earth-current.
In order to solve the problems, such as techniques described above, 500kV terminal box of transformer substation checking for grounded current described in the utility modelPlatform, including at least one ground terminal, at least one current detection module, CSI-200E comprehensive control devices open into plug-in unit,Master Control Room host computer, the ground terminal, current detection module, CSI-200E comprehensive control devices are opened on plug-in unit and Master Control RoomPosition machine is sequentially connected；The current detection module includes current transformer, signal conditioning circuit, singlechip microcontroller, relayDevice exports and power module, and the current transformer, signal conditioning circuit, singlechip microcontroller and relay output sequentially connectIt connects, the current transformer, signal conditioning circuit, singlechip microcontroller, relay output are connected with power module respectively；InstituteIt states singlechip microcontroller and is connected with physical button and liquid crystal screen.
Further, current detection module described in the utility model is the low current detection module that can detect AC 0-100mA.
Preferably, the utility model, which states ground terminal and current detection module, is respectively set as three, each ground terminalThe CSI-200E comprehensive controls device is connected to after the sub connection with a corresponding current detection module to open into plug-in unit.
Ground terminal and current detection module described in the utility model can equipment be as needed one or more, eachGround terminal is connected with a corresponding low current detection module, and more low current detection modules are all connected to the CSI-200EComprehensive control device is opened into plug-in unit, and CSI-200E comprehensive control devices are opened is connected to Master Control Room host computer into plug-in unit.
According to the feature of terminal box N-terminal breakdown current milliampere grade, the low current detection module selection single-chip microprocessor MCU controlUnder current transformer as detection scheme, have a function of detection AC 0-100mA precision low currents, precision is high, sensitivityHeight, stability are good.The current detection module includes current transformer, signal conditioning circuit, singlechip microcontroller, relayOutput and power module, the current transformer, signal conditioning circuit, singlechip microcontroller and relay output sequentially connectIt connects, the current transformer, signal conditioning circuit, singlechip microcontroller, relay output are connected with power module respectively；InstituteIt states singlechip microcontroller and is connected with physical button and liquid crystal screen.
The beneficial effects of the utility model：The utility model provides a kind of 500kV substation PTs terminal box earthing detectionPlatform searches difficulty after can solving the problems, such as the insurance breakdown of PT terminal box N-terminals, is carried out to earth-current to PT terminal boxs remote in real timeRange monitoring quickly determines fault point, makes corresponding counter-measure, saved cost of human resources, improves substation and manages effectBenefit.
Description of the drawings
Fig. 1 is the structural schematic block diagram of the utility model；
Fig. 2 is the structure and connection signal block diagram along the grounding small current detection module of A-B lines in Fig. 1.
Specific implementation mode
The utility model is further described with reference to the accompanying drawings and examples.
500kV terminal box of transformer substation checking for grounded current platform described in the utility model, including at least one ground terminal1, at least one current detection module 2, CSI-200E comprehensive control devices are opened into plug-in unit 3, Master Control Room host computer 4, the ground connectionTerminal 1, current detection module 2, CSI-200E comprehensive control devices are opened and are sequentially connected into plug-in unit 3 and Master Control Room host computer 4；It is describedCurrent detection module 2 includes current transformer 5, signal conditioning circuit 6, singlechip microcontroller 7, relay output 8 and power supplyModule 11, the current transformer 5, signal conditioning circuit 6, singlechip microcontroller 7 and relay output 8 are sequentially connected with, instituteState current transformer 5, signal conditioning circuit 6, singlechip microcontroller 7, relay output 8 are connected with power module 11 respectively；The singlechip microcontroller 7 is connected with physical button 9 and liquid crystal screen 10.
Further, current detection module 2 described in the utility model is the low current detection module that can detect AC 0-100mA.
Preferably, ground terminal 1 described in the utility model and current detection module 2 are respectively set as three, each connectsGround terminal is connected to the CSI-200E comprehensive controls device after being connected with a corresponding current detection module and opens into plug-in unit3。
Embodiment：As shown in Figure 1, the 500kV terminal box of transformer substation earthing detection platform, including three connecting terminals 1,Three low current detection modules 2, CSI-200E comprehensive control devices are opened into plug-in unit 3, Master Control Room host computer 4；First ground terminalBe connected with the first low current detection module, the second ground terminal is connected with the second low current detection module, third ground terminal withThird low current detection module is connected, the first low current detection module, the second low current detection module and the detection of third low currentModule is opened with CSI-200E comprehensive control devices to be connected into plug-in unit 3, and CSI-200E comprehensive control devices are opened to be connected into plug-in unit 3Master Control Room host computer 4；As shown in Fig. 2, the low current detection module 2 includes current transformer 5, signal conditioning circuit 6, monolithicMachine microcontroller 7, relay output 8 and power module 11, the current transformer 5, signal conditioning circuit 6, microcontroller micro-controlDevice 7 and relay output 8 processed is sequentially connected with, the current transformer 5, signal conditioning circuit 6, singlechip microcontroller 7, relayDevice output 8 is connected with power module 11 respectively；The singlechip microcontroller 7 is connected with physical button 9 and liquid crystal screen 10；ThisIn embodiment, ground terminal is connected to current transformer 5, relay output 8 be connected to CSI-200E comprehensive control devices open intoPlug-in unit 3.
According to the feature of terminal box N-terminal breakdown current milliampere grade, the low current detection module 2 selects single-chip microprocessor MCU controlCurrent transformer under system has the function of detection AC 0-100mA precision low currents, precision height, sensitivity as detection schemeHeight, stability are good.
The current transformer 5 be using electromagnetic induction principle exploitation be used under electrically isolated condition measure direct current, exchange,The sensor of pulse and various irregular waveform electric currents, it has high-precision, low-power consumption, responds fast, linear good feature, resistsInterference performance is strong.
The signal conditioning circuit 6 is used for improving the current signal of the acquisition of current transformer 5, through suitably amplifying, filtering, liftOriginal current signal is converted into the standard voltage signal that collecting device microcontroller can identify by lift operations.
The singlechip microcontroller 7 is used for master control low current detection module 2, and reliability is high, can work for a long timeThe analog signal that signal conditioning circuit 8 accesses can be converted into digital signal by fault-free, integrated ADC analog-to-digital conversion modules,Facilitate MCU calculation processings.The introducing of singlechip microcontroller 7 can solve PT terminal boxs milliampere grade leakage current to access device essenceDegree requires high, the not ideal enough problem of small current mutual inductor actual tests effect.
8 two states with open and close of relay output, cut-off for controlling connect dry contact；Dry contactWithout polarity between two contacts, can be interchanged.
The physical button 9 is used for facilitating Field Force to key in or change electric current bound setting SET value at any time.
The liquid crystal screen 10 is used for the surveyed ground pin current size of real-time display, and substation employee scene is facilitated to seeIt surveys.
The power module 11 is used for current transformer 5, signal conditioning circuit 6, singlechip microcontroller 7, relayIt exports 8 each sections and supplies correspondingly sized voltage.
The CSI-200E comprehensive controls device is opened has 24 way switch amount input functions into plug-in unit 3, equal per way switch amountIt may be configured as long delay or short delay.
The Master Control Room host computer 4 is used for examining by each ground terminal of configuration software real-time display in substation's Master Control RoomSurvey state.
Specific work process is as follows：
Whole device is made of host computer and slave computer.Slave computer is installed at the scene, and PT terminal box N-terminal current signals are completedExtraction, digitized processing, the display of monitoring parameters and relay output, slave computer passes through last state on communication lineBe transmitted to host computer, host computer obtain can carry out after the data that slave computer uploads Dynamic Announce, historical data automatically save andAnalysis and preliminary fault diagnosis etc.；Data exchange is carried out by existing cable between host computer and slave computer.
The current transformer 5 of slave computer low current detection module 2 is nested in monitoring PT terminal box N-terminals and obtains initial data,Collected electric current amplifies through signal conditioning circuit 6, filters, lifting is converted to voltage signal, and access singlechip microcontroller 7 collectsAt ADC analog-to-digital conversion I/O ports, after the digital signal progress calculation processing that microcontroller gets conversion, pass through LCD liquid crystals screen 10It shows measurement data, while control is compared according to the electric current bound SET value set using physical button 9 with Field ForceRelay switching, if being disconnected in the normally opened node for limiting control relay output 8 in range 0-20mA, if out-of-limit control relayThe normally opened node of output 8 is closed；8 offer dry contact of relay output is opened through on-site cable access CSI-200E comprehensive control devicesIt is uploaded to Master Control Room host computer 4 after entering 3 any way switch amount input node of plug-in unit.The connected dry contact in the road disconnects software and is determined asLow level, host computer interface show the ground terminal state " normal "；The connected dry contact in the road is closed software and is determined as high level, onThe position machine interface display ground terminal state "abnormal".
Only example goes out a kind of scheme of the utility model above, in real work, the current detection module and ground terminalIt can be increased or decreased according to scale, as long as scheme connection as described above achieves that.