CN2053388U - Electric leakage protector with high-frequency current method - Google Patents

Abstract

The utility model discloses an electric leakage protector with high frequency current method which selectively protect electric leakage. A high frequency current, and a magnetic ring receiving signal are adopted; thus, three phase earth insulation symmetrical, and asymmetric reducing both has reliable selectivity. Gas, coal dust, and electric detonator can not explode by electric leakage electric current due to the high speed of electric breaking, reliably ensuring the safety of underground mine. The electric leakage protector with high frequency current method is suitable for the branch system of a neutral point grounding system, a neutral point non-grounding system, a single phase, three phase, four wire type direct current power supply system with 10 kilovolt, or less than 10 kilovolt, and the electric leakage production of terminal load. The utility model can be used for full electric network, local electric network, or a single device; meanwhile, the electric leakage protector with high frequency current method can match with a leak detection relay, such as JY-82 type, etc., a current feedback switch, and a magnetic force switch to use.

Description

Electric leakage protector with high-frequency current method

The utility model is a kind of relevant electric selective earth leakage protective device.

When equipment such as cable, switch, motor in use especially move in the down-hole, owing to making moist or reason such as water inlet, often cause that three phase isolated evenly reduces simultaneously, the person touches a phase power supply or relatively during metallic short circuit, will cause very big earth current, the person of 660 volts of electric power system maximums is touched earth current can be reached more than the 300mA, one relatively the earth current of metallic earthing can be up to more than the 700mA, and this is easy to cause accident of human electric shock and gas, coal dust, electric cap explosion accident.Therefore, (is 11K Ω to 660 volts of systems) must cut off the power supply immediately when the three-phase insulation against ground dropped to a certain degree, searched accident point, carried out accident treatment.For a long time, people just explore when electric leakage and do not jump master switch, and open failure section circuit selectively, thereby find the fault point rapidly.Present electric earth leakage protecting method has three kinds: a kind of is additional direct current method leakage relay (see for details eelctrical engineering handbook second fascicle in colliery underground power supply used and throw light on 5～35 pages), and this method can not realize the selectivity tripping operation; A kind of is earth leakage search/lockout method (see for details eelctrical engineering handbook second fascicle in colliery underground power supply used and throw light on 5～39 pages), and this method can only realize earth leakage search/lockout, can not realize the selectivity tripping operation; Another is zero sequence drying method and zero sequence direction power method (Beijing Red Star explosion-proof electric apparatus factory produces the explanation of BJJ-660/380 flame-proof mine selectivity leak detection relay), this method can only realize the selectivity tripping operation of the asymmetric reduction of three phase isolated, and can not realize that because of no residual voltage and zero-sequence current selectivity trips for three symmetrical reductions.These three kinds of methods all can not solve and can the selectivity tripping operation can realize three symmetrical earth leakage protective problems again.

For the three symmetrical electric leakages that solve various power voltage supply modes and the selectivity of asymmetric electric leakage; dwindle the scope that influences production because of electric leakage; processing accident rapidly, ad hoc meter come out to realize the optionally earth leakage protective device that has of three symmetrical electric leakages and asymmetric electric leakage with the method for additional high electric current.

The utility model is made up of stabilized voltage power supply, high-frequency current transmitter, high-frequency current receiver, flip and flop generator, gate-controlled switch, emission magnet ring, reception magnet ring and high frequency capacitance current compensator.Stabilized voltage power supply is made up of one ampere of silicon rectification bridge, three terminal regulator and filter capacitor.36 volts of input ac voltages, its output dc voltage are 24 volts.Electric current is 0～200mA.The high-frequency current transmitter is made up of the bikini oscillator power amplifier.Tranmitting frequency is 1～50 kilocycle, and power is 0.5W, is sinusoidal waveform.The high-frequency current receiver is made up of two-stage tuned amplifier and triode detector.Sensitivity is about 1mV.Flip and flop generator is made up of NAND gate circuit and circuits for triggering and indicator light.And can indicate the operating state of protected circuit.Gate-controlled switch is made up of 12 amperes of bidirectional triode thyristors.Emission magnet ring and reception magnet ring transmit and receive high-frequency signal respectively.The high frequency capacitance current compensator.The high frequency capacitance current over the ground of compensation protected circuit section; Also can use high frequency capacitance electric current automatic compensator when being used for the branch system protection.High frequency capacitance electric current automatic compensator is made up of compensation magnet ring, compensation condenser and high frequency voltage automatic regulator.Automatic regulator is by compensation magnet ring input control voltage, by the constant high frequency voltage of emission magnet ring input phase, and imports self-regulating high-frequency electrical capacitive offset current by compensation condenser to receiving magnet ring.

This high-frequency current method selective leakage protection device is work like this: get 36 volts of voltages of down-hole magnetic switch, power supply as operation circuit, press the startup knob, the switch connection power supply, motor start-up, the auxiliary contact of magnetic switch is connected stabilized voltage power supply, and high frequency transmitter sends high frequency voltage, by the emission magnet ring high-frequency signal is coupled to supply line's get on (or be coupled with the high frequency series filter); When the protected circuit section was not leaked electricity operate as normal, protected section high frequency capacitive earth current was compensated by the high frequency capacitance current compensator, made the reception magnet ring not have high frequency voltage output (or being lower than setting); The insulation against ground of protected circuit section symmetry reduces or is asymmetric when being reduced to a certain degree (along separate routes below the 30K Ω; separate unit 50K Ω is following); or the person is when getting an electric shock; the protected circuit section just has the resistive electric current of high-frequency electrical to go into ground by receiving magnet ring; the reception magnet ring induces high-frequency signal and is input to receiver, makes bistable state change operating state through amplification demodulator, and former double-basis utmost point pipe produces and triggers the interruption of silicon controlled triggering signal; the outage of protected circuit section, malfunction indicator lamp D ₂Bright, the staff can in time find to handle this part of path fault; Other protected circuits Duan Yin does not have the resistive electric current of high-frequency electrical to go into ground, still work as usual.Be not out of order a little influence has realized high-frequency current method earth leakage protective selectively.As be used for branch system protection.When the operational outfit platform number of protected circuit section changes; the high frequency capacitive earth current also changes thereupon; and the output voltage of compensation magnet ring also changes thereupon; Linear Control by the high frequency voltage automatic regulator; make it that high frequency compensation voltage is also followed the variation of high frequency capacitive earth current and equal proportion ground changes; thereby reach the automatically effect of compensation of capacitive earth current, make it to equal zero or be lower than setting by the high frequency capacitance electric current that receives ring.When resistive ground leaks electricity,, and induce high-frequency signal at the reception magnet ring owing to the resistive leakage current of high-frequency electrical can not be compensated.Make triggering signal stop (or generation) through the receiver amplification, make protected shunt outage, reach the purpose of branch system selective protection.

Fig. 1 explanation.This figure is a fundamental diagram of the present utility model.1. stabilized voltage power supply 2. high-frequency current receivers 3. emission magnet rings 4. receive magnet ring 5. high-frequency current receivers 6. flip and flop generators 7. gate-controlled switches 8. high frequency capacitance current compensators

The utility model is because adopted the additional high electric current and magnet ring reception signal. All have reliably selectively so the three-phase insulation against ground is symmetrical with asymmetric reduction, because outage speed is fast, so leakage current can not set off an explosion to gas, coal dust and electric cap, makes the safety of mine that more reliable assurance be arranged.

The utility model can be used for earth neutral system and isolated neutral system, can be used for 10 kilovolts and following single-phase, three-phase, four-wire system, the earth leakage protective of the branch system of DC power-supply system and terminal load. But full electric network uses, but also partial electric grid or single device are used, and can be used with leak detection relay, feeding switch, the magnetic switch such as Jy-82 type.

Claims (4)

1, a kind of high-frequency current method earth leakage protective device, formed by stabilized voltage power supply, high-frequency current transmitter, high-frequency current receiver, flip and flop generator, gate-controlled switch, emission magnet ring, reception magnet ring and high frequency capacitance current compensator, it is characterized in that: stabilized voltage power supply is by 1 ampere of silicon rectification bridge, three terminal regulator and filter capacitor are formed, 36 volts of input ac voltages, its output dc voltage is 24 volts, and electric current is 0～200mA; The high-frequency current transmitter is made up of bikini oscillator and worker's rate amplifier, and tranmitting frequency is 1～50 kilocycle, and power is 0.5W, is sinusoidal waveform; The high-frequency current receiver is made up of two-stage tuned amplifier and wave detector, and sensitivity is about 1mV; Flip and flop generator is made up of NAND gate circuit, circuits for triggering and indicator light; Gate-controlled switch is made up of bidirectional triode thyristor; stabilized voltage power supply is supplied with the complete machine DC power supply; high frequency transmitter is launched high frequency voltage; the emission magnet ring is coupled to (or with filter coupled) in the supply line with high-frequency signal, the normal high frequency capacitive earth current in high frequency capacitance current compensator compensation protective wire highway section.When the insulation against ground of protected circuit section symmetry reduces or asymmetric (separate unit 50K when being reduced to specified degree

, shunt 30K

); or the person when getting an electric shock the protected circuit section just have the resistive electric current of high-frequency electrical to go into ground by receiving magnet ring; the high-frequency signal that induces is input to receiver; make bistable state change operating state; former double-basis utmost point pipe produces and triggers the interruption of silicon controlled triggering signal; the outage of protected circuit section, malfunction indicator lamp is bright.

2, as the said earth leakage protective device of claim 1; it is characterized in that: also can adopt automatic compensation; that is: when need are protected with branch system, should take off the high frequency capacitance current compensator and change the automatic compensator of forming by compensation magnet ring, compensation condenser, high frequency voltage automatic regulator into.By compensation magnet ring input control voltage, import self-regulating high-frequency electrical capacitive offset current by the constant high frequency voltage of emission magnet ring input phase and by compensation condenser to receiving magnet ring, thereby finish automatic compensation.

3, as claim 1 or 2 said earth leakage protective devices, it is characterized in that: can make manifold type.

4, as claim 1 or 2 said earth leakage protective devices, it is characterized in that: can make boxlike.

Images