CN2458631Y

CN2458631Y - Insulation detector for electric power DC operating power supply

Info

Publication number: CN2458631Y
Application number: CN 00268771
Authority: CN
Inventors: 孙耀杰; 范融; 樊忠; 王晓峰; 张丽芳
Original assignee: XI'AN LIDA INTELLIGENT ELECTRIC APPLIANCE CO Ltd
Current assignee: XI'AN LIDA INTELLIGENT ELECTRIC APPLIANCE CO Ltd
Priority date: 2000-12-31
Filing date: 2000-12-31
Publication date: 2001-11-07
Anticipated expiration: 2010-12-31

Abstract

The utility model relates to an insulation detector for an electric power DC operating power supply. The power supply comprises a single-chip microprocessor system, the input terminal of the single-chip microprocessor system is connected with the output terminal of an A/D sampling channel to complete the sampling function; the output terminal of the single-chip microprocessor system is connected with a serial communication device to complete the serial communication function; the output terminal of the single-chip microprocessor system is connected with the input terminal of an LCD display unit to complete the display function. The utility model has the advantages that the utility model can reflect the insulation falling-down degree of positive and negative electrodes of a DC system, when the insulation of the positive and negative electrodes is homogeneously or inhomogeneously fallen down, accurate alarm can be realized, the insulation falling-down branch can be accurately judged, no interference is generated to the DC system, and the miss alarm and false alarm can be avoided.

Description

Electric power direct current operative power source insulation tester

The utility model relates to power system automatic field, particularly a kind of electric power direct current operative power source insulation tester.

Domestic insulation tester is mainly used in the detection of bus and control branch road state of insulation and insulation resistance at present, this method exists following defective: for load-sensitive, be not suitable for the capacity load circuit, and the stack AC signal be exactly interference source for DC loop itself, may influence the operate as normal of system; Because of the DC insulation monitoring device that uses is the direct current bridge that utilizes a kind of symmetrical balance; When the insulation of a certain utmost point descends in the direct current, destroyed bridge balance, reflect the insulation status of straight-flow system by uneven degree, it can only reflect positive and negative electrode insulation decline degree; But when the positive and negative electrode insulation evenly descends, install malfunctioning.When the positive and negative electrode inhomogeneous decline of insulating, error is very big.

The purpose of this utility model is to overcome the defective of above-mentioned prior art, the insulation tester that a kind of electric power direct current operative power source is used is proposed, it can reflect straight-flow system positive and negative electrode insulation decline degree, when positive and negative electrode insulation evenly descends or inhomogeneous decline, all can accurately report to the police, and can accurately judge the branch road that insulation descends, and straight-flow system is not produced interference, prevent to fail to report, report by mistake.

For achieving the above object, solution of the present utility model is: it comprises Single Chip Microcomputer (SCM) system, and the input end of Single Chip Microcomputer (SCM) system is connected with the output terminal of A/D sampling channel, finishes the sampling function; The Single Chip Microcomputer (SCM) system output terminal links to each other with serial communication, finishes the serial communication function; The output terminal of Single Chip Microcomputer (SCM) system is connected with the input end of liquid crystal display, finishes Presentation Function.

Below in conjunction with accompanying drawing the technical solution of the utility model is described further.

Fig. 1 is an one-piece construction circuit block diagram of the present utility model.

Fig. 2 is the circuit diagram of the utility model Single Chip Microcomputer (SCM) system 1, Fig. 2-the 1st wherein, the circuit diagram of single-chip microcomputer, storer and programmable chip system PSD, Fig. 2-the 2nd, the circuit diagram of RS485/RS232 and programmable logic device (PLD).

Fig. 3 is the circuit diagram of the utility model sampling channel 2, Fig. 3-the 1st wherein, the circuit diagram of active filter and signal conditioning circuit, Fig. 3-the 2nd, the circuit diagram of analog switch and photoelectric relay.

Referring to Fig. 1, the utility model comprises Single Chip Microcomputer (SCM) system 1, and the input end of Single Chip Microcomputer (SCM) system 1 is connected with the output terminal of A/D sampling channel 2, finishes the sampling function; Single Chip Microcomputer (SCM) system 1 output terminal links to each other with the input end of serial communication 3, finishes the serial communication function; The output terminal of Single Chip Microcomputer (SCM) system 1 is connected with the input end of liquid crystal display 4, finishes Presentation Function; Its principle of work is: at first driven the switch closure of D.C. isolation bridge by Single Chip Microcomputer (SCM) system 1, make the D.C. isolation bridge produce change in voltage, the amplitude of variation is corresponding with the resistance of dc bus insulation against ground resistance, and fixing corresponding relation is arranged.By the variable quantity of A/D sampling channel 2 collection voltage magnitudes, Chip Microcomputer A/D holds (A/D1----A/D4) through filtering conditioning back input.Single Chip Microcomputer (SCM) system 1 can draw dc bus insulation against ground resistance value by calculating.Secondly, if when a certain branch road has insulation to descend, when insulative bridge open/fashionable, the output voltage that the DC leakage current sensor of this branch road can produce 0.5V changes, voltage magnitude is relevant with the degree of insulation decline.A/D sampling channel 2 is gathered the output voltage of each branch road DC leakage current sensor, and be input to Chip Microcomputer A/D and hold (A/D1----A/D4), offering an explanation out through Single Chip Microcomputer (SCM) system 1 specifically is which branch road insulation descends, and drives the work of relay plate, output alarm signal by Single Chip Microcomputer (SCM) system 1.Liquid crystal display 4 links to each other with Single Chip Microcomputer (SCM) system 1, receives the video data from single-chip microcomputer in real time, by the resistance of liquid crystal display 4 demonstration stake resistances, the branch road label of earth fault takes place.

Closed or when opening, A/D sampling channel 2 collects the change in voltage of switch ends, and enters data into liquid crystal display 4 when a certain branch switch, state is opened/closed to the switch that demonstrates each branch road.

Referring to Fig. 2-1, Fig. 2--2, the Single Chip Microcomputer (SCM) system 1 of insulation tester is made up of the circuit of storer and programmable chip system PSD and the circuit of RS485/RS232 and programmable logic device (PLD), it comprises: model is the single-chip microcomputer U3 of 80196KB, model is the programmable chip system U6 of PSD302-B-15, model is the data-carrier store U8 of 2864A, and model is the programmable logic device (PLD) U13 of EPM7128EL, model is the chip U9 of MAX813, model is the not gate U11A of 74HC04, model is the 5V reference source U4 of AD586, model is the chip U12 of MAXM485, model is the serial communication chip M2 of MAX232; Annexation between them is: single-chip microcomputer U3, programmable chip system U6, data-carrier store U8, pass through re/bus between the programmable logic device (PLD) U13, re/addess data/address bus and read-write control signal WR, RD links to each other, single-chip microcomputer U3, chip U12, link to each other with the PORT/T end by PORT/R between the serial communication chip M2,7 pin of chip U9 link to each other with 1 pin of not gate U11A, link to each other with 16 pin of single-chip microcomputer U3 again, 2 pin of not gate U11A link to each other 6 pin of 5V reference source U4 and 1 pin of single-chip microcomputer U1 with the RESET of programmable chip system U6 end, 37 pin, 13 pin link to each other.

Referring to Fig. 3-1, sampling channel 2 of the present utility model comprises an active filter and the signal conditioning circuit of contacting with it.The simulating signal of insulative bridge input is operational amplifier U19 and the active filter of U20 composition and signal conditioning circuit is inputed to single-chip microcomputer U3 by the ACH0 end the ACH0 end of OP07 through model.Power bus sensor output simulating signal is operational amplifier U14 and the active filter of U16 composition and signal conditioning circuit is inputed to single-chip microcomputer U3 by the ACH1 end the ACH1 end of OP07 through model.Control bus sensor output simulating signal is operational amplifier U17 and the active filter of U18 composition and signal conditioning circuit is inputed to single-chip microcomputer U3 by the ACH3 end the ACH3 end of OP07 through model.

Referring to Fig. 3-2, the analog switch of the utility model sampling channel 2 and the circuit of photoelectric relay comprise an insulation branch sensor, the input simulating signal #R1--#R40 of insulation branch sensor, #R65---#R72 is 4050 chip UA1 through model, UB1, UC1, UE1, UF1, the operational amplifier UAA1A that analog switch that UG1 forms and chip model are MC1458, USS1A, the signal conditioning circuit that UAA1B forms, input to the ACH4 end of single-chip microcomputer U3 again by the ACH4 end, model is that the photoelectric relay chip U21 of AQW214 passes through PA5, PA6 links to each other with programmable logic device (PLD) U13, links to each other with insulative bridge by three PORT ends.

The utility model principle of work is: the lower limit that the operator reports to the police by the button isolated input, pass through address/data bus re/bus by programmable logic device (PLD) U13, re/addess is with the value input single-chip microcomputer U3 of button, and through among the data-carrier store U8 (2864A) that restores after the computing, for system call.The PA5 of programmable logic device (PLD) U13 and PA6 end drive photoelectric relay U21 and open/close insulative bridge, and insulative bridge voltage is changed.Insulative bridge voltage signal input (seeing Fig. 3-1) is through the active filter of operational amplifier U19 and U20 composition and the ACH0 end input single-chip microcomputer U3 of signal conditioning circuit.According to the corresponding relation of insulation resistance and insulative bridge input voltage, calculate the size of insulation resistance value, and show by showing first unit 4.

Simultaneously, the input signal #R1--#R40 of direct current Electrical leakage, #R65---#R72 is that the signal conditioning circuit that analog switch and chip UAA1A, U551A, UAA1B form enters the ACH4 end through model, and being determined by single-chip microcomputer U3 is which branch road insulation descends, and shows by the unit.

Single-chip microcomputer U3, chip U12 and serial communication chip M2 form serial communication circuit, send telemetry intelligence (TELINT) to host computer.U4 is the reference power supply of A/D conversion.Model is that reset chip U9 and the model of MAX813 is that the not gate U11 of 74HC04 forms and resets and watchdog circuit, monitors the working condition of whole microcontroller system circuit.

Characteristics of the present utility model are:

1) can detect plus or minus utmost point insulation decline on the bus, and to two utmost points simultaneously evenly Insulation descends and inhomogeneous insulation descends, and all can judge well.

2) can not sending to straight-flow system in the situation of any additional signal, detect 1-The micro-Ground leakage current of 2mA is accurately judged the branch road that insulation descends, and does not have with loadtype Close, be adapted to various load running environment, and straight-flow system is not produced interference. Prevent Fail to report, report by mistake, overcome common insulation monitoring and warning device for the high defective of capacitive load rate of false alarm.

3) insulation resistance value of 0-72 road bus or branch road can be detected, the insulation against ground resistance of 0-250K Ω can be accurately measured;

4) can detect 0-32 switch branch, close state.

5) requirement of the double control property of electric capacity meets GB/T17626.12-1998 and GB/T17626.2-1998;

6) can write down 16 kinds of 48 fault contents.

Claims

1, a kind of electric power direct current operative power source insulation tester, it comprises a Single Chip Microcomputer (SCM) system (1), it is characterized in that, the input end of Single Chip Microcomputer (SCM) system (1) is connected with the output terminal of A/D sampling channel (2), Single Chip Microcomputer (SCM) system (1) output terminal links to each other with the input end of serial communication (3), and the output terminal of Single Chip Microcomputer (SCM) system (1) is connected with the input end of liquid crystal display (4).

2, electric power direct current operative power source insulation tester according to claim 1, it is characterized in that, said Single Chip Microcomputer (SCM) system 1 comprises a single-chip microcomputer U3, single-chip microcomputer U3, programmable chip system U6, data-carrier store U8, pass through re/bus between the programmable logic device (PLD) U13, readdess data/address bus and read-write control signal WR, RD links to each other, single-chip microcomputer U3, chip U12, link to each other with the PORT/T end by PORT/R between the serial communication chip M2,7 pin of chip U9 and 1 pin of U11A link to each other, link to each other with 16 pin of single-chip microcomputer U3 again, 2 pin of not gate U11A link to each other 6 pin of 5V reference source U4 and 1 pin of single-chip microcomputer U1 with the RESET of programmable chip system U6 end, 37 pin, 13 pin link to each other.

3, electric power direct current operative power source insulation tester according to claim 1, it is characterized in that, said sampling channel (2) comprises an active filter and the signal conditioning circuit of contacting with it, active filter reaches the simulating signal of the insulative bridge input in the signal conditioning circuit of contacting with it and holds the ACH0 that inputs to single-chip microcomputer U3 to hold through the active filter and the signal conditioning circuit of operational amplifier U19 and U20 composition by ACH0, power bus sensor output simulating signal is held by the ACH1 that the ACH1 end inputs to single-chip microcomputer U3 through the active filter and the signal conditioning circuit of operational amplifier U14 and U16 composition, and active filter that control bus sensor output simulating signal process operational amplifier U17 and U18 form and signal conditioning circuit are held the ACH3 end that inputs to single-chip microcomputer U3 by ACH3.

4, electric power direct current operative power source insulation tester according to claim 1, it is characterized in that, said sampling channel (2) also comprises the circuit of an analog switch and photoelectric relay, the input simulating signal #R1--#R40 of the insulation branch sensor in the circuit of analog switch and photoelectric relay, #R65--#R72 is through chip UA1, UB1, UC1, UE1, UF1, analog switch and chip UAA1A that UG1 forms, USS1A, the signal conditioning circuit that UAA1B forms, inputed to the ACH4 end of single-chip microcomputer U3 again by the ACH4 end, chip U21 passes through PA5, PA6 links to each other with programmable logic device (PLD) U13 and links to each other with insulative bridge by three PORT ends.