CN87203578U - Electronic preventer for electricleakage - Google Patents

Abstract

The utility model discloses a low-voltage preventer for electric-leakage, comprising an alternating current contactor, a differential mutual inductor and an electronic controller. The electronic controller adopts a low-voltage dc power supply to be as an attracting holding line, and a short-circuited circuit is served as a tripping-operation control circuit; a controllable high voltage pulse generating circuit is served as a switching-on line, and no intermediate relay is used. The utility model has the advantages of low cost, high reliability and small power consumption; the electronic preventer for electric-leakage has the functions of single shot reclosing, manual-operation restoration and remote-control restoration.

Description

Electronic preventer for electricleakage

The utility model relates to a kind of current mode low-voltage leakage protector that electronic control circuit is arranged.

The early stage product of current mode electric leakage (electric shock) protector mostly is pure electromagnetic type greatly.The existing in recent years product that adopts transistor amplifier circuit; such earth leakage protective device introduced in " earth leakage protector product introduction of DBL current mode low pressure and analysis " literary composition in " electronic science and technology " nineteen eighty-three monograph; this earth leakage protective device mostly uses auxiliary relay to control A.C. contactor; cost is than higher; power consumption is also bigger, and does not have the remote control restore funcitons.

The purpose of this utility model is to propose a kind of earth leakage protective device that does not use auxiliary relay.Cost reduction, power consumption are reduced, and another purpose of the present utility model is to make this earth leakage protective device have the remote control restore funcitons.

Earth leakage protective device of the present utility model comprises an A.C. contactor; a differential instrument transformer and an electronic-controlled installation; this electronic-controlled installation comprises that an adhesive keeps circuit; a tripping operation circuit and a combined floodgate circuit; it is a low-voltage dc power supply that described adhesive keeps circuit; one end of the pull-in winding of A.C. contactor is connected on the output of this DC power supply by an isolating diode; its other end ground connection; described tripping operation circuit is a short circuit current; the secondary coil of the differential instrument transformer of its input termination; the output of the described low-voltage dc power supply of its output termination; described combined floodgate circuit is a controllable high-voltage pulse generating circuit, and its output is received the non-earth terminal of contactor pull-in winding.

This earth leakage protective device is work like this: the combined floodgate of earth leakage protective device is to make the A.C. contactor pull-in winding get electric and adhesive by the high-voltage pulse that high-voltage pulse generating circuit produces; after A.C. contactor closes a floodgate; rely on the low-voltage dc power supply power supply to keep attracting state; when electric leakage earth fault takes place in circuit; the signal that induces on the differential instrument transformer secondary coil makes the tripping operation circuit produce a short-circuit signal; with the low-voltage dc power supply shorted to earth, pull-in winding trips immediately because of dead electricity.

Accompanying drawing 1 is the electrical schematic diagram of this electronic leakage protector.

Accompanying drawing 2 is remote controller schematic diagrames supporting with this earth leakage protective device.

Introduce the embodiment of this earth leakage protective device below in conjunction with accompanying drawing.As shown in Figure 1, (1) is the pull-in winding of A.C. contactor CJ among the figure, CJ-1, CJ-2, CJ-3 is often opening and normally-closed contact of A.C. contactor for this reason, (2) be differential instrument transformer, (4) be low-voltage dc power supply, adhesive as A.C. contactor keeps circuit, it is a bridge rectifier with electric capacity C8 series connection step-down, (5) for make the short circuit current of short-circuit component with controllable silicon, mainly comprise a triode amplifier BG1, a diode rectification network and a unidirectional controllable silicon S CR1, the secondary coil of the differential instrument transformer of input termination of amplifier BG1, the output of this amplifier is received the control utmost point of unidirectional controllable silicon S CR1 through commutated network, one output very of controllable silicon SCR 1, receive on the output of low-voltage dc power supply, another utmost point ground connection, (6) be the controllable high-voltage pulse generating circuit, it is bidirectional triode thyristor circuits for triggering, it mainly comprises a bidirectional triode thyristor SCR2, a unidirectional controllable silicon S CR3, a diode D7, a current-limiting resistance R8 and a delay circuit C5, a normally-closed contact CJ-2 and the above-mentioned diode D7 of A.C. contactor, current-limiting resistance R8, receive after the delay capacitor C5 series connection between phase line and zero line of power supply, the utmost point of bidirectional triode thyristor SCR2 is received the non-earth terminal of ac contactor coil, another utmost point connecting to neutral line, unidirectional controllable silicon S CR3 links the control utmost point of bidirectional triode thyristor and the interface of current-limiting resistance R8 and delay capacitor C5.

The course of work of this earth leakage protective device is: after the energized; delay capacitor C5 is by current-limiting resistance R8, diode D7, normally-closed contact CJ-2 charging; after a period of time time-delay; certain voltage, unidirectional controllable silicon S CR3 conducting during charging; C5 discharges to the bidirectional triode thyristor SCR2 control utmost point by SCR3; make SCR2 moment conducting; ac contactor coil (1) obtains a transient state high pressure; adhesive immediately; high direct voltage outage after the adhesive; by low-voltage dc power supply (4) power supply, keep attracting state.When leak current fault; the secondary output signal of differential instrument transformer is amplified after the control utmost point of controllable silicon SCR 1 is delivered in rectification by triode BG1; make the SCR1 conducting; so with dc power output end and ground short circuit; thereby make ac contactor coil (1) dead electricity and trip; this earth leakage protective device one more automatic reclosing function: after the tripping operation, because the normally-closed contact CJ-2 closure of A.C. contactor, the charge circuit of C5 is connected; through behind the delay time; high-voltage pulse of A.C. contactor pull-in winding is given in SCR3 conducting, thereby SCR2 conducting; A.C. contactor is an automatic reclosing; if fault is got rid of, the just success of closing a floodgate is not if fault is got rid of; then tripping operation immediately again; because reclosing is very short to the time of tripping operation again, the C5 discharge does not finish as yet, and the anode current of SCR3 is still greater than keeping electric current; SCR3 remains conducting; no longer send trigger impulse, and this to keep electric current be deficiency so that bidirectional triode thyristor SCR2 triggers, so A.C. contactor CJ remains tripped condition.Will recover to close a floodgate, the switch AN2 closure that delay capacitor C5 Shang And need be joined discharges the electric charge on the capacitor C 5 again, and earth leakage protective device just returns to the standby condition of automatic closing again.

Also have in the high-voltage pulse generating circuit of this earth leakage protective device one shake control restore circuit (7) it by triode BG2 filter network C6, R6, C7 and current-limiting resistance R7 forms, the collector and emitter of triode BG2 is moved delay capacitor C5 to two ends, its base stage is received on arbitrary phase line of A.C. contactor main contacts user side by another normally-closed contact CJ-3 of filter network, current-limiting resistance and A.C. contactor.

As shown in Figure 2; this earth leakage protective device shakes the remote controller that control recovers usefulness; can make with a battery (8), a current-limiting resistance (9) and a positive electrode rod (10), a ground connection connecting line (11); the positive pole of battery is received on the positive electrode rod (10) through current-limiting resistance, and the negative pole of battery links to each other with ground connection connecting line (11).The voltage of battery is 12～18 volts, and the resistance of described current-limiting resistance is 1.5～20 kilo-ohms.

When shaking the control recovery operation, the ground connection connecting line of remote controller is connect the earth, the arbitrary phase line of positive electrode rod (10) contact user side, because the power consumption equipment of user side is connected three phase lines mutually, the voltage of remote controller can be added on the base stage of the triode BG2 that shakes the control restore circuit, so the electric charge on the BG2 conducting delay capacitor C5 is released, has returned to the standby condition of automatic closing again.When power consumption equipment was three-phase four-wire system, zero line need disconnect with power consumption equipment by a contact (CJ-4) of A.C. contactor, just can shake the control recovery operation.

In sum; the earth leakage protective device that the utility model proposes; do not use auxiliary reclay; cost is lower, again owing to the method that has adopted high-voltage pulse combined floodgate, low-voltage direct to keep, little power consumption; stable and reliable operation And and have single shot reclosing manually recovers and shakes the function that control recovers, and is easy to use. The all parts of this earth leakage protective device can be fitted together makes a product, also differential mutual induction device and electronic control circuit can be made an independent product and other A.C. contactor adapted.

Claims (7)

1; a kind of current mode low-voltage leakage protector; comprise an A.C. contactor; a differential instrument transformer (2); adhesive keeps circuit (4); tripping operation circuit (5) and combined floodgate circuit (6); it is characterized in that it is a low-voltage dc power supply that described adhesive keeps circuit (4); one end of the pull-in winding of described A.C. contactor (1) is connected on the output of this low-voltage dc power supply from pipe (D5) by an isolation two; its other end ground connection; described tripping operation circuit (5) is a short circuit current; the secondary coil of the aforementioned differential instrument transformer of its input termination; the output of the described low-voltage dc power supply of its output termination; described combined floodgate circuit (6) is a controllable high-voltage pulse generating circuit, and its output is received the non-earth terminal of A.C. contactor pull-in winding (1).

2, earth leakage protective device as claimed in claim 1 is characterized in that described low-voltage dc power supply is the bridge rectifier with a capacitances in series step-down.

3, earth leakage protective device as claimed in claim 1 or 2; it is characterized in that described short circuit current comprises a triode amplifier; a commutated network and a one-way SCR as short-circuit component; the secondary coil of the differential instrument transformer of input termination (2) of described triode amplifier, its output are received very output of of the one-way SCR control utmost point, this silicon controlled, another utmost point ground connection through commutated network.

4; earth leakage protective device as claimed in claim 3; it is characterized in that described high-voltage pulse generating circuit comprises a bidirectional triode thyristor; an one-way SCR; a diode; a current-limiting resistance and a delay capacitor; a normally-closed contact and the above-mentioned diode of described A.C. contactor; current-limiting resistance; receive after the delay capacitor series connection between phase line and zero line of power supply; one utmost point of bidirectional triode thyristor connects the non-earth terminal of A.C. contactor pull-in winding; another utmost point connecting to neutral line, one-way SCR links the control utmost point of bidirectional triode thyristor and the interface of current-limiting resistance and delay capacitor.

5, earth leakage protective device as claimed in claim 4; it is characterized in that described high-voltage pulse generating circuit (6) also comprises a remote control restore circuit (7) of being made up of triode, filter network and current-limiting resistance; the collector electrode of above-mentioned triode, emitter are received the two ends of described delay capacitor, and its base stage is received on arbitrary phase line of contactor main contacts user side by another normally-closed contact of filter network, current-limiting resistance and contactor.

6, a kind of earth leakage protective device recovers the remote controller of usefulness; it is characterized by it and comprise a battery, a current-limiting resistance, a positive electrode rod and a ground connection connecting line; the positive pole of above-mentioned battery is received on the positive electrode rod through current-limiting resistance, and the negative pole of battery links to each other with the ground connection connecting line.

7, remote controller as claimed in claim 6, the voltage that it is characterized in that described battery is 12～18 volts, the resistance of described current-limiting resistance is 1.5～20 kilo-ohms.