CN2869878Y

CN2869878Y - Microcomputer small-current earthing line-selection apparatus

Info

Publication number: CN2869878Y
Application number: CN 200520135569
Authority: CN
Inventors: 王常栋
Original assignee: LBD ELECTRIC CO Ltd
Current assignee: LBD ELECTRIC CO Ltd
Priority date: 2005-12-15
Filing date: 2005-12-15
Publication date: 2007-02-14
Anticipated expiration: 2015-12-15

Abstract

A microcomputer low current earthing wire-selecting device, which belongs to a detection technique fieldIt is designed to effectively improve the wire-selecting accuracy in the event of the single-phase earthing in system. The technical proposal is that the utility model comprises a wire-selecting section and an integrated management section; the wire-selection section comprises a data acquisition input circuit and a data processing output circuit; the data acquisition input circuit is so formed that a signal processing circuit, a multiplex imput switch, a latch, a programmable controller, and an A/D converter circuit are connected in sequence, then connected to the input end of the CPU 1 of the wire-selection control; the data processing output circuit comprises a latch, a photo-electric isolating circuit , a driver, an output port of CPU of the relay wire-connection & selection control; the integrated management section comprises an integrated control CPU 2, a display and communication device; the display and the communication device is connected to each interface of the CPU 2; the wire-selection control CPU 1 and the intergrated control CPU 2 are connected by a serial port.

Description

The microcomputer Small Electric Current Earthing And Routing Device

Technical field

The utility model relates to isolated neutral in a kind of electric system or through the Small Electric Current Earthing And Routing Device of arc suppression coil or resistance eutral grounding, belongs to technical field of measurement and test.

Background technology

Small current system is meant not solidly grounded system of neutral point, and it comprises three types of isolated neutral system, neutral by arc extinction coil grounding system or neutral point resistance grounded systems.In the electrical network of 66kV and following electric pressure thereof, generally all adopt this system.Behind the small current system generation single-phase earthing, fault signature is also not obvious, causes quick and precisely indicating ground loop that certain difficulty has been arranged.Since the eighties Small Electric Current Earthing And Routing Device comes out, experienced several times and updated, though its performance improves constantly, but still there is the False Rate problem of higher.

Current, the selection method that general Small Electric Current Earthing And Routing Device is taked, be according to when small current system generation earth fault, the zero-sequence current that flows through fault element is numerically equal to the capacitive earth current sum of all non-fault elements, be zero-sequence current maximum on the faulty line, so as long as just can find out faulty line by the size that compares zero-sequence current amplitude and setting valve one by one.But this method can not be got rid of the unbalanced influence of TA, be subjected to the influence of circuit length, system operation mode and transition resistance size, and may there be the situation of the capacitance current of certain bar circuit in the system greater than other all line capacitance electric current sums, malfunction easily takes place in device, is not suitable for the system through grounding through arc.

Summary of the invention

Technical problem to be solved in the utility model is to overcome the defective of above-mentioned prior art and a kind of microcomputer Small Electric Current Earthing And Routing Device that can improve the earthing wire-selecting accuracy when being intended to system's generation single-phase earthing effectively is provided.

The technical scheme that addresses the above problem is:

A kind of microcomputer Small Electric Current Earthing And Routing Device, be grouped into by route selection part and general management department, route selection partly comprises signal processing circuit, the multichannel input switch, latch, Programmable Logic Controller, the A/D change-over circuit, route selection control CPU1, light is every circuit, driver, relay, wherein, described signal processing circuit, the multichannel input switch, latch, Programmable Logic Controller, the A/D change-over circuit connects the input end of back selecting line traffic control singlechip CPU 1 successively, form the data acquisition input circuit jointly by them, described latch, light is every circuit, driver, the output terminal of relay selecting line traffic control CPU1 is formed the output circuit of data processing jointly by them; Described general management department divides and comprises Comprehensive Control CPU2, demonstration and communication device, and wherein, demonstration and communication device are connected to each interface of Comprehensive Control CPU2; Connect by serial communication between route selection control single chip computer CPU1 and the Comprehensive Control singlechip CPU 2.

Above-mentioned microcomputer Small Electric Current Earthing And Routing Device, described data acquisition input circuit is constructed as follows: by resistance R 1, the low-pass filter circuit that capacitor C is formed, the signal processing circuit that the ZW voltage stabilizing diode is formed, its input end connects the signal output part of the voltage transformer (VT) summation current transformer on the monitored circuit, the output terminal of signal processing circuit is connected to the gating input end of multichannel input switch IC5, the P4 mouth of CPU1 connects the data port of Programmable Logic Controller IC2, the B1 output of Programmable Logic Controller IC2 connects the input end of AD conversion chip IC3, the address gating signal input end of B2 output termination latch IC4, the data port of latch IC4 connects the P3 mouth of CPU1, output terminal Q1, Q2, Q3, Q4 connects the A0 of multichannel input switch IC5 respectively, A1, A2, the EN end, the output terminal COM of IC5 connects the input end of AD conversion chip IC3, the P3 mouth of the parallel data output termination CPU1 of AD conversion chip IC3.

Above-mentioned microcomputer Small Electric Current Earthing And Routing Device, described data processing output circuit is by latch IC11, IC12, IC13, IC14, light is every circuit, driver IC 15, IC16, relay K A forms, their connected mode is: the P3 mouth of CPU1 meets latch IC11, the data port of IC12, latch IC11, the control signal end of IC12 connects the B6 of Programmable Logic Controller IC2, the B7 output terminal, the output terminal of latch IC11 meets latch IC13 through light after device is isolated, the data port of IC14, the output of latch IC12 meets latch IC13 through light every device, the chip selection signal input end of IC14, latch IC13, the output terminal of IC14 is driver connected IC15 respectively, IC16, driver IC 15, the output terminal of IC16 is connected with each relay respectively again.

Above-mentioned microcomputer Small Electric Current Earthing And Routing Device, described integrated management part is made up of Comprehensive Control singlechip CPU 2, liquid crystal IC23, keyboard, communication module; Wherein, communication module is made up of counter IC24, serial extended chip IC25, serial communication chip IC 26, IC27, IC24 adopts 8253, IC25 adopts 8251, IC26 adopts RS232 communication module chip MAX202, and IC27 adopts RS485/RS422 communication module chip MAX1490, and the TXD of IC25, RXD are connected to T1IN, the R1OUT of IC26, the T1OUT of IC26 is connected to the RS232 mode data receiver of CPU1, and the R1IN of IC26 is connected to the RS232 mode data sending terminal of CPU1; The P3 mouth of control CPU2 is as the data port of data line connection IC23, and the latter's gating signal connects the B1 output terminal of Programmable Logic Controller IC22; The P0.0-P0.7 of control CPU2 connects keyboard;

The utility model is collected residual voltage and all circuit zero sequence current data of bus, adopt digital filter, signal is carried out effective digital filtering to be handled, extracted more reliable signal content, by microcomputer adopt principle of relativity to amplitude and phase place sort, overall treatment such as judgement, realized intelligent route selection, avoided, the ground current little erroneous judgement that cause changeable, improved the accuracy of earthing wire-selecting because of the method for operation.

Description of drawings

Fig. 1 is an electric theory diagram of the present utility model;

Fig. 2 is CT, PT wiring schematic diagram;

Fig. 3 is a data acquisition input circuit electrical schematic diagram;

Fig. 4 is a data processing output circuit electrical schematic diagram;

Fig. 5 is an integrated management part electrical schematic diagram;

Fig. 6 is the communication part electrical schematic diagram;

Fig. 7 is the main program process flow diagram.

Embodiment

Below at first the utility model is analyzed and is narrated by functional block:

1. route selection part

Route selection partly comprises the input of data acquisition and the output circuit of data processing, and the input of data acquisition is made up of CT1, signal processing circuit, multichannel input switch IC5, latch IC4, Programmable Logic Controller IC2, the AD converter IC3 of the PT1 that handles the residual voltage signal in the device, processing zero sequence current signal.PT1 adopts the 100V/3.53V mutual inductor, totally 4 of full configurations, and CT1 adopts the 5A/3.53V mutual inductor, totally 36 of full configurations, IC5 adopts MAX308, totally 5 of full configurations; IC4 adopts 74LS273, and IC2 adopts GAL16V8, and AD converter IC3 adopts and includes 12 AD1674 integrated chips that kept by three-state buffer and sampling.Below only to one tunnel signal instruction, voltage acquisition signal on the PT1 is taken from the residual voltage UO1 of industry spot, current acquisition signal on the CT1 is taken from the zero-sequence current I01 of industry spot, the low-pass filter circuit that signal after the mutual inductor conversion is formed via resistance R and capacitor C, the signal processing circuit that the ZW mu balanced circuit is formed is handled the input end of receiving multichannel input switch IC5, the P4 mouth of CPU1 connects the data port of IC2, the latter's B1 output is as the data-switching switch of AD conversion chip, the B2 output terminal is as the address gating signal of latch IC4, the data port of latch IC4 connects the P3 mouth of CPU1, and the A0A1A2 that output terminal Q1Q2Q3 connects multichannel input switch IC5 respectively constitutes the switch decoded signal; Output terminal Q4 connects the chip selection signal of the EN end of multichannel input switch IC5 as switch, and the output terminal COM of IC5 connects the input end of AD conversion chip IC3, the P3 mouth of the parallel data output termination CPU1 of AD conversion chip, and the P3 mouth that reads CPU1 can obtain sampled data.

The output circuit of data processing is made up of every circuit, driver IC 15, IC16, relay K A latch IC11, IC12, IC13, IC14, light.Wherein latch IC11, IC12, IC13, IC14 all adopt 74LS273, totally 2 of the full configurations of IC13, totally 5 of the full configurations of IC14; Driver IC 15, IC16 adopt ULN2003, totally 3 of the full configurations of IC15, totally 6 of the full configurations of IC16.The P3 mouth of CPU1 meets IC11, the data port of IC12, IC11, the control signal of IC12 connects the B6 of Programmable Logic Controller IC2, the B7 output terminal, the output of IC11 meets IC13 through light every device TLP521 isolation as CPU1 data processing output data, the data port of IC14, the output of IC12 is through light each latch IC13 when device TLP521 isolates as data output processing, the chip selection signal end of IC14, the driver connected IC15 of the output of IC13, the latter drives relay, the normally opened contact of relay is exported as remote motion signal, the driver connected IC16 of the output of IC14, the latter drives relay, and the normally opened contact of relay is exported as trip signal.

2. integrated management part

The integrated management part is made up of liquid crystal IC23, keyboard, pilot lamp, communication module.Wherein liquid crystal IC23 adopts the Chinesizing Liquid Crystal Module of 240 * 128 dot matrix, communication module is made up of counter IC24, serial extended chip IC25, serial communication chip IC 26, IC27, IC24 adopts 8253, IC25 adopts 8251, IC26 adopts RS232 communication module chip MAX202, and IC27 adopts RS485/RS422 communication module chip MAX1490.The P3 mouth of control CPU2 is as the data port of data line connection IC23, and the latter's gating signal connects the B1 output terminal of Programmable Logic Controller IC22; The P1.1-P1.2 of control CPU2 connects the led state pilot lamp, button is touched in the P0.0-P0.7 connection;

If 1,3 of jumper wire device SP3 connects, communication interface TXD, T2IN, the R2OUT that RXD is connected to IC26 of control CPU2, the T2OUT of IC26 is connected to the data sending terminal of outside RS232, the R2IN of IC26 is connected to the data receiver of outside RS232, if 1,2 of jumper wire device SP3 connects, communication interface TXD, DI, the RO that RXD is connected to IC27 of control CPU2, the A of IC27, B, Z, Y end are connected to outside RS485/RS422 communication interface; The P3 mouth of control CPU2 is as the data port of data line connection serial extended chip IC25, timer conter IC24, and the chip selection signal of IC24, IC25 connects B6, the B7 output terminal of Programmable Logic Controller IC22.The clock CLK end of the oscillator output end mouth XTAL2 linkage counter IC24 of control CPU2 and the clock CLK end of serial extended chip IC25, the output OUT of counter IC24 connects transmission receive clock TXCLK, the RXCLK of serial extended chip IC25.The TXD of IC25, RXD are connected to T1IN, the R1OUT of IC26, and the T1OUT of IC26 is connected to the RS232 mode data receiver of CPU1, and the R1IN of IC26 is connected to the RS232 mode data sending terminal of CPU1.

Below be described further in conjunction with the accompanying drawings again:

Fig. 2 shows outside CTPT wiring schematic diagram of the present utility model.The data object of the processing of microcomputer Small Electric Current Earthing And Routing Device be from industry spot the bus residual voltage signal and the zero sequence current signal of these bus outlets.The open delta connection type is adopted in the wiring of bus residual voltage, and promptly the signal that obtains after joining end to end of A, B, C three-phase PT is exactly the residual voltage signal UO on this bus, and this device maximum can be handled 4 road buses, difference called after UO1, UO2, UO3, UO4 (referring to Fig. 2 (a)).For the outlet zero sequence current signal, according to the outlet method wiring of each outlet, for overhead outlet, when A, B, C three-phase CT are arranged, adopt zero sequence filtrator form, the homopolar end of A, B, C three-phase CT also meets the zero sequence current signal I0 (referring to Fig. 2 (b)) that can obtain this outlet.For only having A, C two-phase CT to lack B phase CT, attention should be adopted no-load voltage ratio, precision and A, the on all four B of C two-phase CT mutually.For cable outlet, the CT signal adopts the method for suit zero sequence CT, the polar end of zero-sequence transformer CT up, the non-polar end ground connection of secondary side, the crust ground wire should pass CT.This device maximum can be handled 36 tunnel outlets, difference called after IO1, and IO2 ... (referring to Fig. 2 (c)) by that analogy.

Fig. 3 shows X5-1, the X5-2 of the signal difference access device among above-mentioned Fig. 2; X5-3, X5-4 ..., X5-9, X5-10 ...Corresponding respectively PT1-PT4, the CT1-CT36 of connecting of these connection terminals.PT will be changed to the small voltage signal through V/V from the residual voltage signal of bus, CT is changed to the small voltage signal with each zero sequence current signal through I/V, and these signals enter multichannel input switch IC5 in signal processing circuit respectively after the RC low pass filtered involves ZW voltage stabilizing processing.When the chip selection signal EN of IC5 is high level, this switch is by gating, according to the respective channel on this switch of decoding value gating of address code A0, A1, A2, AD converter IC3 just can be read the sampled data of this passage by the output terminal of IC5, and this analog quantity is converted to digital quantity be sent to route selection CPU1 by data port, the P3 mouth that reads route selection CPU1 can obtain sampled data.

After Fig. 4 has shown that this device detects circuit generation earth fault, route selection control CPU1 output fault data, fault data through latch, light can drive the telemechanical end that the user is notified in the corresponding telemechanical actuating of relay after the output of, switch, the action of driving tripping relay, can disconnect this outlet, eliminate fault, whether the user trips after can setting fault in program.The output contact of relay is all normally opened contact, and the telemechanical relay normally open contact is connected to the telemechanical plug-in card of device, and tripping relay is connected to the respective terminal of device tripping operation case, and the user can select to connect as required.

Referring to Fig. 6, route selection control CPU1 and overall treatment CPU2 adopt two 80C196 circuit chips, are connected by serial ports between them.T1IN, R1OUT that the communication interface TXD of route selection CPU1, RXD are connected to IC6, the T1OUT of IC6 are connected to the RS232 mode data receiver of control CPU2, and the R1IN of IC6 is connected to the RS232 mode data sending terminal of control CPU2.Because cpu chip itself has only one group of serial ports, control CPU2 has adopted the communication module of the expansion of serial extended chip IC25, timer conter IC24 composition to expand one group of serial ports, the oscillator output end mouth XTAL2 of control CPU2 provides the clock source of counter IC24 and serial extended chip IC25, the time-delay number of counter is write by data bus by CPU2, and this group serial ports is used for communicating by letter with route selection CPU1.

Fig. 7 has shown the basic flow sheet of program, when the microcomputer Small Electric Current Earthing And Routing Device of this structure normally moves in monitored system, device is monitoring CT/PT signal in real time, when small current system generation single-phase earthing, the zero-sequence current of faulty line is other non-fault line zero-sequence current sum, and it is maximum in this group sampled value in principle.But, generally can not surpass first three because CT error, sampling error, signal interference and circuit length difference great disparity might be discharged to second, third when ordering.This step is primary election, and the principle that is adopted also is the relative value notion; In second step, in first three signal, employing relative phase notion is promptly used the direction between the electric current or the phase place between electric current and the voltage is leading and lagged relationship, determines that further that line failure still is that bus breaks down in first three.Because this device has been realized the residual voltage of bus and all circuit zero sequence current data are collected, adopt digital filter, signal is carried out effective digital filtering to be handled, extracted more reliable signal content, by microcomputer adopt principle of relativity to amplitude and phase place sort, overall treatment such as judgement, realized intelligent route selection, avoided, the ground current little erroneous judgement that cause changeable, improved the accuracy of earthing wire-selecting because of the method for operation.

Claims

1. microcomputer Small Electric Current Earthing And Routing Device, it is characterized in that, it is grouped into by route selection part and general management department, route selection partly comprises signal processing circuit, the multichannel input switch, latch, Programmable Logic Controller, the A/D change-over circuit, route selection control CPU1, light is every circuit, driver, relay, wherein, described signal processing circuit, the multichannel input switch, latch, Programmable Logic Controller, the A/D change-over circuit connects the input end of back selecting line traffic control CPU1 successively, form the data acquisition input circuit jointly by them, described latch, light is every circuit, driver, the output terminal of relay selecting line traffic control CPU1 is formed the output circuit of data processing jointly by them; Described general management department divides and comprises Comprehensive Control CPU2, demonstration and communication device, and wherein, demonstration and communication device are connected to each interface of Comprehensive Control CPU2; Connect by serial communication between route selection control CPU1 and the Comprehensive Control CPU2.

2. microcomputer Small Electric Current Earthing And Routing Device according to claim 1, it is characterized in that, described data acquisition input circuit is constructed as follows: by resistance R 1, the low-pass filter circuit that capacitor C is formed, the signal processing circuit that the ZW voltage stabilizing diode is formed, the signal output part of the voltage transformer (VT) summation current transformer on the monitored circuit of its input termination, the output terminal of signal processing circuit is connected to the gating input end of multichannel input switch IC5, the P4 mouth of CPU1 connects the data port of Programmable Logic Controller IC2, the B1 output of Programmable Logic Controller IC2 connects the input end of AD conversion chip IC3, the address gating signal input end of B2 output termination latch IC4, the data port of latch IC4 connects the P3 mouth of CPU1, output terminal Q1, Q2, Q3, Q4 connects the A0 of the defeated people's switch I C5 of multichannel respectively, A1, A2, the EN end, the output terminal COM of IC5 meets the input end of AD conversion chip IC3, the P3 mouth of the parallel data output termination CPU1 of AD conversion chip IC3.

3. microcomputer Small Electric Current Earthing And Routing Device according to claim 2, it is characterized in that, described data processing output circuit is by latch IC11, IC12, IC13, IC14, light is every circuit, driver IC 15, IC16, relay K A forms, their connected mode is: the P3 mouth of CPU1 meets latch IC11, the data port of IC12, latch IC11, the control signal end of IC12 connects the B6 of Programmable Logic Controller IC2, the B7 output terminal, the output terminal of latch IC11 meets latch IC13 through light after device is isolated, the data port of IC14, the output of latch IC12 meets latch IC13 through light every device, the chip selection signal input end of IC14, latch IC13, the output terminal of IC14 is driver connected IC15 respectively, IC16, driver IC 15, the output terminal of IC16 is connected with each relay respectively again.

4. according to claim 1,2 or 3 described microcomputer Small Electric Current Earthing And Routing Devices, it is characterized in that described integrated management part is made up of Comprehensive Control singlechip CPU 2, liquid crystal IC23, keyboard, communication module; Wherein, communication module is made up of counter IC24, serial extended chip IC25, serial communication chip IC 26, IC27, IC24 adopts 8253, IC25 adopts 8251, IC26 adopts RS232 communication module chip MAX202, and IC27 adopts RS485/RS422 communication module chip MAX1490, and the TXD of IC25, RXD are connected to T1IN, the R1OUT of IC26, the T1OUT of IC26 is connected to the RS232 mode data receiver of CPU1, and the R1IN of IC26 is connected to the RS232 mode data sending terminal of CPU1; The P3 mouth of control CPU2 is as the data port of data line connection IC23, and the latter's gating signal connects the B1 output terminal of Programmable Logic Controller IC22; The P0.0-P0.7 of control CPU2 connects keyboard.