CN102393485A

CN102393485A - Detection module for multi-loop leakage current

Info

Publication number: CN102393485A
Application number: CN2011102746840A
Authority: CN
Inventors: 傅俊豪; 傅加发; 傅汉水; 傅哲龙
Original assignee: FUJIAN JUNHAO ELECTRONICS Co Ltd
Current assignee: FUJIAN JUNHAO ELECTRONICS Co Ltd
Priority date: 2011-09-16
Filing date: 2011-09-16
Publication date: 2012-03-28

Abstract

The invention relates to a detection module for multi-loop leakage current, which comprises a current transformer leakage signal acquisition circuit, a fire control linkage external trigger circuit and a singlechip control circuit. Multiple output signals of the current transformer leakage signal acquisition circuit are transmitted to an analog-to-digital (A/D) data conversion circuit through an operational amplification rectification regulation circuit and an analog switch circuit in sequence, and the output signals of the A/D data conversion circuit and the fire control linkage external trigger circuit are sent to an RS485 communication interface circuit, a carrier signal phase lock circuit and a relay drive circuit through the singlechip control circuit. The module has a function of multi-loop leakage detection and is capable of detecting the leakage faults of multiple loops of a distribution system; after synthetic judgment is performed by a singlechip, an alarm signal is sent to a host machine through a carrier signal or RS485 bus to effectively give an alarm in time at the very first time; and when the leakage faults are generated, the loop with leakage can be identified, and the leakage fault detection time is effectively shortened.

Description

Multiloop leakage current detection module

Technical field

The present invention relates to a kind of detection module, particularly be a kind of multiloop leakage current detection module.

Background technology

The electrical fire major part causes fire because of supply line or equipment live wire Leaked Current of Line to Ground, and electric leakage has the comparison disguise, so leak current fault should have the long-distance monitoring and alarming function, and tradition electric leakage product only has the onsite alarming function.

Summary of the invention

The objective of the invention is to overcome above-mentioned deficiency, a kind of multiloop leakage current detection module is provided.

The technical solution adopted for the present invention to solve the technical problems is: a kind of multiloop leakage current detection module; Comprise current transformer electric leakage signal Acquisition Circuit, fire-fighting link external trigger circuit and single chip machine controlling circuit; The current transformer electric leakage signal Acquisition Circuit output signal of multichannel is delivered to the A/D data converting circuit through amplifier rectification adjustment circuit, analog switching circuit successively; The output signal of A/D data converting circuit and fire-fighting link external trigger circuit sends to RS485 communication interface circuit, carrier signal phase lock circuitry, relay drive circuit through single chip machine controlling circuit, and the output signal of said carrier signal phase lock circuitry sends to the carrier signal decoding scheme through the frequency-selecting amplifier circuit.

Said single chip machine controlling circuit and watchdog circuit bidirectional data transfers.

Said current transformer electric leakage signal Acquisition Circuit is gathered current signal through the amorphous ZCT.

Said fire-fighting link external trigger circuit by the triggering direct current signal that fire alarm control unit sends send to resistance successively, the photoelectricity coupled circuit constitutes.

Said RS485 communication interface circuit transmits warning message through system bus to the fire protection control center PC through SN75176 signal transmitting and receiving chip.

Said carrier signal phase lock circuitry is made up of LM567 tone decoder and peripheral electric capacity, the resistance that connects thereof.

Said frequency-selecting amplifier circuit is made up of elementary, the capacitor of first triode, first audio-frequency transformer (AFT), and sends data-signal through electric wire to the carrier signal decoding scheme through the secondary of first audio-frequency transformer (AFT).

Said carrier signal decoding scheme is made up of second audio-frequency transformer (AFT), LM567 ATD, second triode and the light emitting diode that connect successively.

Through adopting above-mentioned technical scheme, the invention has the beneficial effects as follows: the present invention has the multiloop detection of electrical leakage, can detect the leak current fault in a plurality of loops of distribution system; After the comprehensive judgement of single-chip microcomputer; Send alerting signal through carrier signal or RS485 bus to main frame, the timely and effective very first time reports to the police, when leak current fault takes place; Can identify which loop, effectively shorten leak current fault detection time.

Description of drawings

Fig. 1 is a frame assumption diagram of the present invention;

Fig. 2 is circuit theory diagrams of the present invention.

Embodiment

As shown in Figure 1; A kind of multiloop leakage current detection module of the present invention; Comprise current transformer electric leakage signal Acquisition Circuit 1, fire-fighting link external trigger circuit 2 and single chip machine controlling circuit 3; The current transformer electric leakage signal Acquisition Circuit 1 output signal of multichannel is delivered to A/D data converting circuit 13 through amplifier rectification adjustment circuit 11, analog switching circuit 12 successively; The output signal of A/D data converting circuit 13 and fire-fighting link external trigger circuit 2 sends to RS485 communication interface circuit 4, carrier signal phase lock circuitry 5, relay drive circuit 8 through single chip machine controlling circuit 3; The output signal of said carrier signal phase lock circuitry 5 sends to carrier signal decoding scheme 7 through frequency-selecting amplifier circuit 6, said single chip machine controlling circuit 3 and watchdog circuit 9 bidirectional data transfers.

This module adopts the amorphous ZCT to gather zero sequence current signal, and phase line and zero line should pass zero sequence current mutual inductor simultaneously, gathers leakage current signal; When phase line had earth fault, magnetic flux and no longer wait zero produced small induced voltage signal; This voltage signal is sent to analog switch after amplification, rectification, carry out the shunt cycle detection; When a certain monitoring loop surpasses the setting leakage current value; Handle through the single-chip microcomputer logical data,, reach fire protection control center through RS485 system bus signal or carrier signal output.

As shown in Figure 2; Form first via electric leakage signal Acquisition Circuit by amorphous ZCT LN, resistance 3R1, diode D1, diode D2, electric capacity 3C2 etc.; When the live wire that passes amorphous ZCT LN has earth fault; LN level of amorphous ZCT produces the fine leak electric signal and is input to analog switching circuit IC2 the 13rd pin; Detect electric leakage signal through analog switching circuit IC2 cycling switch, by the 3rd pin output of analog switching circuit IC2, after operational amplifier IC3 internal arithmetic is amplified; After diode D5 rectification, electric capacity 3C4 filtering, resistance 3R5 dividing potential drop; Be input to the 2nd pin of A/D data converter IC6 again, after the inner A/D data-switching of A/D data converter IC6, form datel circuit by the 5th, 6,7 pin and single-chip microcomputer IC1 the 6th, 25,39 pin of A/D data converter IC6; Single-chip microcomputer IC1 reads the electric leakage data-signal after A/D data converter IC6 conversion; When the 2nd pin input end M1 point current potential of A/D data converter IC6 surpasses setting value, through single-chip microcomputer IC1 read and through internal processes is comprehensive judge after, send control signal; The first via is exported communication interface the 1st pin, 2,3,4 pin that are connected respectively to the 1st pin, the 2nd pin, the 3rd pin and the SN75176 signal transmitting and receiving chip IC 5 of control chip IC4 by single-chip microcomputer IC1 the 10th pin, the 11st pin, the output of the 25th pin serial data, transmits warning message through system bus to the fire protection control center PC; The second tunnel output is formed phase lock circuitry by the multivibrator that LM567 tone decoder U1 and peripheral electric capacity 2C1, resistance 2R1, resistance 2R2 thereof constitute; Its oscillation frequency is by the parameter determining of electric capacity 2C1, resistance 2R1, and carrier frequency is adjusted in the 150-300KHZ scope.Elementary L1, electric capacity 2C2, capacitor 2C3 by triode Q1, audio-frequency transformer (AFT) T constitute the frequency-selecting amplifier circuit; The 4th pin output high level signal by single-chip microcomputer IC1; Make LM567 tone decoder U1 obtain working power; LM567 tone decoder U1 starts working, and is coupled on local telephone network speaking wire or the AC network AC220V power lead and is sent by secondary L2, the electric capacity 1C4 of audio-frequency transformer (AFT) T, sends data-signal to the carrier wave main frame; Audio-frequency transformer (AFT) T1, LM567 ATD U2, triode Q2, LED by connecting successively constitute the carrier signal decoding scheme; The time constant of resistance 1R1, electric capacity 1C5 network has determined the voltage controlled oscillator of LM567 ATD U2; When the carrier wave extension set when main frame sends 150-300KHZ carrier wave command signal; Be coupled to the secondary L3 of audio-frequency transformer (AFT) T through electric capacity 1C1, audio-frequency transformer (AFT) T1, its secondary L3, electric capacity 1C2, electric capacity 1C3 form a carrier wave frequency selection network.Signal after the frequency-selecting is coupled to the 3rd pin signal input part of LM567 ATD U2 through electric capacity 1C4; After LM567 ATD U2 decoding,, make triode Q2 conducting by its 8th pin output terminal output low level; LED is lighted; Receive the carrier data signal of extension set, explained to occur leak current fault, reached real time and on line monitoring.

Form fire-fighting link external trigger circuit by resistance 3R10, photoelectricity coupled circuit IC7, resistance 3R11 etc., when fire took place, fire alarm control unit sent the triggering direct current signal; This signal makes photoelectricity coupled circuit IC7 conducting through resistance 3R10 current limliting, and the 2nd pin I/O of single-chip microcomputer IC1 end also is low level state simultaneously; And make triode Q1 get into conducting state; Promote relay J 1 adhesive, breaker device shunt opening coil gets electric, the circuit breaker tripping outage; Supply line loses power supply, protection fire fighter fire-fighting safety.After the comprehensive judgement of single-chip microcomputer IC1 internal processes, IC1 sends drive signal by single-chip microcomputer, drives SN75176 signal transmitting and receiving chip IC 5 and transmits warning message through system bus to the fire protection control center PC, shows current off-position.

The second road electric leakage signal Acquisition Circuit principle is identical with first via electric leakage signal Acquisition Circuit principle, no longer repeats here.

Above-describedly be merely a preferred embodiment of the present invention, can not limit the scope that this practicality is implemented, every equalization of doing according to claim of the present invention changes and decorates, and all should still belong to the scope that the present invention is contained.

Claims

1. multiloop leakage current detection module; It is characterized in that: comprise current transformer electric leakage signal Acquisition Circuit (1), fire-fighting link external trigger circuit (2) and single chip machine controlling circuit (3); Current transformer electric leakage signal Acquisition Circuit (1) the output signal of multichannel is delivered to A/D data converting circuit (13) through amplifier rectification adjustment circuit (11), analog switching circuit (12) successively; The output signal of A/D data converting circuit (13) and fire-fighting link external trigger circuit (2) sends to RS485 communication interface circuit (4), carrier signal phase lock circuitry (5), relay drive circuit (8) through single chip machine controlling circuit (3), and the output signal of said carrier signal phase lock circuitry (5) sends to carrier signal decoding scheme (7) through frequency-selecting amplifier circuit (6).

2. multiloop leakage current detection module according to claim 1 is characterized in that: said single chip machine controlling circuit (3) and watchdog circuit (9) bidirectional data transfers.

3. multiloop leakage current detection module according to claim 1 is characterized in that: said current transformer electric leakage signal Acquisition Circuit (1) is gathered current signal through the amorphous ZCT.

4. multiloop leakage current detection module according to claim 1 is characterized in that: said fire-fighting link external trigger circuit (2) by the triggering direct current signal that fire alarm control unit sends send to resistance successively, the photoelectricity coupled circuit constitutes.

5. multiloop leakage current detection module according to claim 1 is characterized in that: said RS485 communication interface circuit (4) transmits warning message through system bus to the fire protection control center PC through SN75176 signal transmitting and receiving chip.

6. multiloop leakage current detection module according to claim 1 is characterized in that: said carrier signal phase lock circuitry (5) is made up of LM567 tone decoder and peripheral electric capacity, the resistance that connects thereof.

7. multiloop leakage current detection module according to claim 1; It is characterized in that: said frequency-selecting amplifier circuit (6) is made up of elementary, the capacitor of first triode, first audio-frequency transformer (AFT), and sends data-signal through electric wire to carrier signal decoding scheme (7) through the secondary of first audio-frequency transformer (AFT).

8. multiloop leakage current detection module according to claim 1 is characterized in that: said carrier signal decoding scheme (7) is made up of second audio-frequency transformer (AFT), LM567 ATD, second triode and the light emitting diode that connect successively.