CN106257782B - Ac leakage drives protector - Google Patents

Abstract

The invention discloses an AC leakage drive protector, which includes a fault detection circuit of the AC protector and a leakage drive protection unit. The drive unit includes a set of relay contacts and a capacitor. One end of the capacitor (C1) is connected to the first contact of the relay ( 24), the other end of the capacitor is connected to the one-phase line of the AC power supply, the second contact (21) of the relay is connected to the second contact (11) of the fault detection circuit; the first contact (12) of the fault detection circuit is connected to the ground wire, and the fault detection The third contact (14) of the circuit is an empty end; when the AC power supply circuit fails, the phase line, capacitor, and relay contacts are closed, the second contact at the output end of the fault detection circuit is connected to the first contact, and the grounding line Constitute the leakage detection driving circuit, control the leakage switch (LK) to disconnect. When the AC leakage drive protector of the present invention fails in the power supply circuit, the leakage drive protection unit can drive the leakage protector to cut off the AC power supply circuit, thereby improving the safety and reliability of the power supply network.

Description

AC leakage drive protector

technical field

The invention relates to an AC protector, in particular to an AC leakage drive protector.

Background technique

At present, the three-phase AC power supply faults of the power supply network mainly include: wrong phase, lack of phase, overvoltage, undervoltage, unbalance, lack of zero, lack of ground, and overcurrent. The faults of single-phase AC power supply mainly include: overvoltage, undervoltage, lack of zero, lack of ground, and overcurrent. The air switch and circuit breaker with leakage protection function in the existing three-phase power supply circuit have overcurrent and leakage protection functions for the three-phase circuit, and have the ability to cut off the circuit itself, see Figure 1; other power supply fault protection is through electronic Protection is achieved by a cut-off and control circuit composed of an electrical protection device (such as a three-phase AC protector) and an AC contactor. For example, a three-phase AC protector is installed in the protection circuit of a three-phase power supply circuit by a representative electronic and electrical product. Contact 11, third contact 14, three-phase AC power supply A, B, C connected to the input terminal of the three-phase AC protector; when the three-phase AC power supply phase A, B, C is working normally, the leakage air switch LK is closed , the second contact 11 and the first contact 14 of the output end of the three-phase AC protector are closed, the working coil JK of the AC contactor is closed, the AC contactor K is turned on, and the load (such as the motor M) is connected to the three-phase AC power supply . When the phases A, B, and C of the three-phase AC power supply fail, the first contact 11 and the third contact 14 at the output end of the three-phase AC protector are disconnected, the working coil JK of the AC contactor is released, and the AC contactor K is disconnected , the load (such as motor M) is disconnected from the three-phase AC power supply. The three-phase AC protector cuts off the AC contactor working coil JK circuit through the detected fault signal and controls the contacts 11 and 14 of its own output, so that the AC contactor K disconnects the power supply circuit to obtain the purpose of protecting the load.

However, the defect of the existing power supply network is that the leakage air switch LK only has its own function of cutting off the circuit. Open, by cutting off the working coil JK of the AC contactor, thereby disconnecting the AC contactor K to cut off the circuit. Figure 1 discloses a three-phase power supply circuit protection circuit, and the single-phase power supply circuit protection circuit is the same as the three-phase power supply circuit protection circuit.

Contents of the invention

The purpose of the present invention is to provide an AC leakage drive protector. When the AC leakage drive protector fails in the power supply circuit, the leakage drive protection unit can drive the leakage protector to cut off the AC power supply circuit, improving the safety and reliability of the power supply network. simplifies the implementation of control circuits and protection circuits.

In order to realize above-mentioned technical purpose, the present invention adopts following technical scheme:

An AC leakage drive protector, including a fault detection circuit of the AC protector, the fault detection circuit includes an AC power input terminal, and multiple sets of contacts at the output end, each set of contacts is three, respectively the first contact , The second contact and the third contact, the second contact is internally connected to a switch, which can be connected to the first contact or the third contact; the fault detection circuit is connected to the AC power supply end;

The AC leakage drive protector also includes a leakage drive protection unit, the drive unit includes a set of relay contacts and a capacitor, one end of the capacitor is connected to the first contact of the relay, the other end of the capacitor is connected to a phase line of the AC power supply, and the second contact of the relay Point the second contact of the fault detection circuit; the first contact of the fault detection circuit is connected to the ground wire, and the third contact of the fault detection circuit is an empty end; The points are closed, the second contact of the output end of the fault detection circuit is connected to the first contact, and the grounding wire forms a leakage detection drive circuit, which controls the leakage switch to be disconnected.

The relay is a time-delay pick-up relay.

The leakage drive protection unit includes two sets of relay contacts and capacitors, one end of the circuit composed of the first set of relay contacts and capacitors is connected to a phase line, and the other end is connected to the second contact of the first group of output terminals of the fault detection circuit, One end of the circuit formed by the second group of relay contacts and capacitors is connected to another phase line, and the other end is connected to the second group of second contacts at the output end of the fault detection circuit.

The leakage drive protection unit includes two sets of relay contacts and capacitors, one end of the circuit composed of the first set of relay contacts and capacitors is connected to a phase line, and the other end is connected to the second contact of the first group of output terminals of the fault detection circuit, One end of the circuit formed by the second group of relay contacts and capacitors is connected to another phase line, and the other end is connected to the first group of second contacts at the output end of the fault detection circuit.

The fault detection circuit is a voltage fault detection circuit or a current fault detection circuit.

The AC protector is a single-phase AC protector, the leakage drive protection unit is installed in the single-phase AC protector, and the single-phase AC protector is made into a protector plug, which matches the socket installed in the single-phase AC line .

The AC leakage drive protector of the present invention includes a fault detection circuit and a leakage drive protection unit. The fault detection circuit is generally included in the AC protector. When the power supply circuit fails, the leakage drive protection unit drives the leakage protection in the existing AC power supply protection circuit. device, thereby cutting off the AC power supply circuit.

The present invention compares with prior art, and its beneficial effect is:

The present invention utilizes the leakage protector with leakage protection function, the air switch, and the circuit breaker to cut off the circuit, which not only protects against short circuit, leakage, and overcurrent, but also protects against other faults in the power supply network, such as phase loss, lack of Zero, lack of ground, overvoltage, undervoltage, wrong phase, unbalance, etc., play a protective role. Thus, the AC contactor in the AC protection circuit is subtracted, and the cost of the protection function is reduced.

The leakage drive protection unit of the AC leakage drive protector of the present invention is combined with the AC protector with fault detection function to form a new generation of AC protector that can directly drive the leakage protection air switch and the leakage protection circuit breaker, which simplifies the protection function , popularization, and does not affect the use of the output contact of the AC protector as the contact of the control circuit.

The AC leakage drive protector of the invention solves the limitation of using an AC contactor to cut off the main circuit in the fault protection of three-phase AC power supply and single-phase AC power supply fault protection of the current power supply network. The invention utilizes a leakage protector (or leakage switch) to cut off the main circuit when the power supply network fails, simplifies the way of cutting off the power supply and distribution circuit, reduces accessories, saves power distribution costs, and uses a leakage protector with a high safety factor to cut off the circuit. The safety and reliability of the power supply network are greatly improved, the losses caused by power distribution faults are indirectly reduced, and the implementation of control circuits and protection circuits is simplified.

Description of drawings

Figure 1 is a schematic diagram of an existing three-phase power supply circuit protection circuit;

Fig. 2 is the schematic circuit diagram of the AC leakage drive protector of the present invention connected to the three-phase AC power supply;

Fig. 3 is another schematic circuit diagram of the AC leakage drive protector of the present invention connected to a three-phase AC power supply;

Fig. 4 is the schematic circuit diagram of the AC leakage drive protector of the present invention connected to a single-phase AC power supply;

Fig. 5 is another schematic circuit diagram of the AC leakage drive protector of the present invention connected to a single-phase AC power supply;

Fig. 6 is a schematic circuit diagram of the AC leakage drive protector of the present invention combined with the protector in the form of a plug to connect to a single-phase AC power supply.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

Referring to Fig. 2 and Fig. 3, an AC leakage drive protector includes a fault detection circuit of the AC protector, the fault detection circuit includes AC power input terminals A, B, C, N, and multiple sets of contacts at the output end, There are three contacts in each group, which are respectively the first contact 12, the second contact 11 and the third contact 14. The second contact 11 is internally connected with a switch, which can be connected to the first contact 12 or the third contact. Contact 14; the fault detection circuit is connected to the output end of the leakage switch LK, see Fig. 2; or, the fault detection circuit is connected to the input end of the leakage switch LK.

The AC leakage drive protector also includes a leakage drive protection unit, the drive unit includes a set of relay contacts and a capacitor C1, one end of the capacitor C1 is connected to the first contact 24 of the relay, and the other end of the capacitor C1 is connected to a phase line C of the AC power supply Phase, the second contact 21 of the relay is connected to the second contact 11 of the fault detection circuit; the first contact 12 of the fault detection circuit is connected to the ground wire, and the third contact 14 of the fault detection circuit is an empty terminal. When the AC power supply circuit fails, the phase line C, capacitor C1, relay contacts 24 and 21 are closed, the second contact 11 and the first contact 12 at the output end of the fault detection circuit are turned on, and the ground wire constitutes the leakage detection drive loop, the leakage detection drive loop controls the leakage switch LK to disconnect.

In order to enable the three-phase AC protector to be connected to the output terminal of the leakage protector (leakage switch LK), the relay in the leakage drive protection unit is a delay pick-up relay, so that the leakage detection of the leakage drive protection unit when the leakage protector is powered on The drive circuit is disconnected to ensure reliable power-on of the leakage protector.

The leakage drive protection unit includes two groups of relay contacts and capacitors. One end of the circuit composed of the first group of relay contacts 24, 21 and capacitor C1 is connected to a phase line C phase, and the other end is connected to the first group of output terminals of the fault detection circuit. One end of the circuit composed of the second contact 11 of the second group of relay contacts 44, 41 and capacitor C2 is connected to the other phase line B, and the other end is connected to the second group of second contacts 31 of the output end of the fault detection circuit. The first contact 12 of the first group of the output end of the fault detection circuit and the first contact 32 of the second group are all connected to the ground wire, and the third contact 14 of the first group of the output end of the fault detection circuit and the third contact 14 of the second group are all connected to the ground wire. The contacts 34 are all empty ends. See Figure 2.

The leakage drive protection unit includes two groups of relay contacts and capacitors. One end of the circuit composed of the first group of relay contacts 24, 21 and capacitor C1 is connected to a phase line C phase, and the other end is connected to the first group of output terminals of the fault detection circuit. One end of the circuit composed of the second contact 11 of the second group of relay contacts 44, 41 and capacitor C2 is connected to the other phase line B phase, and the other end is connected to the second contact 11 of the first group of the fault detection circuit output end. The first contact 12 of the first group of the output end of the fault detection circuit is connected to the ground wire, and the third contact 14 of the first group of the output end of the fault detection circuit is set as an empty terminal, see FIG. 3 . The wiring line in Figure 2 is preferred.

The fault detection circuit is a voltage fault detection circuit or a current fault detection circuit.

The working process of the AC leakage drive protector of the present invention is as follows:

Referring to Figure 2 and Figure 3, when there is no power and the leakage switch LK (or leakage protector) is ready to be powered on, the leakage drive protection unit of the AC leakage drive protector, such as the first group of two delay pick-up relays The contacts 21 and 24 are in the disconnected state, so the leakage detection driving circuit is not conducting, and the leakage detection driving circuit of the other group is also not conducting, and the leakage switch LK can be powered on. When the AC power of the three-phase A, B, and C phases is normal after power-on, the output contact in the fault detection circuit in the AC leakage drive protector of the present invention is turned on, such as the second contact connected to the output contact of the C phase. Point 11, the third contact 14 is turned on, the second contact 11 is disconnected from the first contact 12, and the three-phase AC power supply is connected to the load normally; After power-on, the two contacts 24 and 21 of the delay pull-in relay enter the conduction state from the disconnected state after a delay.

When a fault occurs in a certain phase of the three-phase AC power supply, the second contact 11 of the output contact of the fault detection circuit in the AC leakage drive protector is turned on by the second contact 11 and the third contact 14. disconnected, and the second contact 11 and the first contact 12 turn from disconnection to conduction, that is, the second contact 11 and the first contact 12 conduct, at this time, the leakage drive protection unit of the AC leakage drive protector The delay pick-up relay contacts 21, 24 are in a conduction state, then the C-phase current passes through the capacitor C1 and the two contacts 21, 24 of the delay pick-up relay, and then passes through the second contact 11 and the second contact 11 of the fault detection circuit The first contact 12 and the ground wire form a leakage current loop, that is, a leakage detection drive circuit, so that the leakage switch LK (leakage protector) is activated, and the three-phase AC power input is cut off to the load circuit. In order to obtain a reliable leakage current even when the phase is open, the leakage drive protection unit of the AC leakage drive protector can be equipped with more than one set of relay contacts and capacitors, see Figure 2 and Figure 3 to obtain a reliable leakage current.

The fault detection circuit mentioned above is a voltage fault detection circuit. The implementation of the voltage fault detection circuit is: directly obtain the voltage signal from the three-phase or single-phase, input the electronic circuit of the AC protector for judgment and relay contact output, and then input To the leakage drive protection unit of the present invention, the purpose of protection is achieved.

If the fault detection circuit is a current fault detection circuit, the implementation of the current fault detection circuit is as follows: add a current transformer to the main circuit, use three current transformers for the three-phase circuit, and use one current transformer for the single-phase circuit, and pass through the main circuit wire. In the center of the overcurrent transformer, the induced current generated when the current passes is input into the electronic circuit of the AC protector for judgment and relay contact output. Similarly, it is further input into the leakage drive protection unit of the present invention to achieve the protection purpose.

For single-phase AC circuits, a single-phase three-wire system includes one phase wire, one neutral wire, and one ground wire. In a single-phase AC circuit, combined with a single-phase AC protector to deal with power supply faults such as overvoltage, undervoltage, and abnormal voltage caused by broken zero line, it can directly drive an air switch with leakage protection function and a circuit breaker to cut off the circuit to obtain Protect.

Referring to Fig. 4 and Fig. 5, a single-phase AC leakage drive protector includes a fault detection circuit of the single-phase AC protector. Points, respectively the first contact 12, the second contact 11 and the third contact 14, the second contact 11 is internally connected to a switch, which can be connected to the first contact 12 or the third contact 14; fault detection The circuit is connected to the lower end of the single-phase AC power supply after entering the leakage switch LK.

The leakage drive protection unit is a set of delay pull-in relay contacts and capacitor C1, one end of capacitor C1 is connected to the first contact 24 of the relay, the other end of capacitor C1 is connected to the phase line L of the AC power supply, and the second contact of the delay pull-in relay 21 is connected to the second contact 11 of the fault detection circuit; the first contact 12 of the fault detection circuit is connected to the ground wire, and the third contact 14 of the fault detection circuit is an empty terminal. When a fault occurs in the single-phase AC power circuit, the phase line L, the capacitor C1, the relay contacts 24 and 21 are closed, the second contact 11 and the first contact 12 at the output end of the fault detection circuit are connected, and the ground wire constitutes a leakage detection The driving circuit, the leakage detection driving circuit controls the leakage switch LK to be disconnected.

When there is no electricity in the normal state and the leakage switch LK (leakage protector) is ready to be powered on, the two contacts 21 and 24 of the delay pull-in relay of the leakage drive protection unit of the single-phase AC leakage drive protector of the present invention are in the disconnected state , so the leakage detection drive circuit is not turned on, and the leakage switch LK can be powered on. When the single-phase AC power supply is normal after power-on, the second contact 11 and the third contact 14 of the output contact in the fault detection circuit in the single-phase AC protector are conducted, and the second contact 11 and the first contact 12 disconnected, and the single-phase AC power supply is normally connected to the load; since the delay pull-in relay is used in the leakage drive protection unit, after power-on, the two contacts 24 and 21 of the delay pull-in relay are disconnected after a delay. state into the conduction state.

When the single-phase AC power supply fails, the second contact 11 of the output contact of the fault detection circuit in the AC leakage drive protector of the present invention is turned into disconnection by the second contact 11 and the third contact 14. And the second contact 11 and the first contact 12 turn from disconnection to conduction, that is, the second contact 11 and the first contact 12 are conducted, and at this moment, the delay pull-in relay contact 21 of the leakage drive protection unit , 24 are in the conduction state, then the single-phase current passes through the capacitor C1 and the two contacts 21, 24 of the delay pull-in relay, and then passes through the second contact 11 and the first contact 12 of the fault detection circuit to form a grounding line The leakage current loop, that is, the leakage detection drive circuit, activates the leakage switch LK (leakage protector) and cuts off the single-phase AC power input to the load circuit.

The AC leakage drive protector of the present invention utilizes the fault detection circuit of the existing AC protector, innovatively proposes a leakage drive protection unit, and combines the two to form the AC leakage drive protector of the present invention. Therefore, the leakage drive protection The unit is integrated in the existing AC protector, such as a three-phase AC protector or a single-phase AC protector, and a discharge circuit is formed for the ground wire in the protector to drive the leakage protector, which can reduce accessories and make the protection function simple and popular change. The leakage amount of the leakage drive protection unit of the AC leakage drive protector can be realized by changing the capacity of the capacitor C to achieve different rated voltage levels and leakage levels. The leakage amount of the leakage protector (or leakage switch) is determined according to national standards. .

The AC leakage drive protector of the present invention can be used in any wire power supply network such as three-phase three-wire system, three-phase four-wire system, three-phase five-wire system, single-phase three-wire system, two-phase three-wire system, and protect its circuit .

The AC leakage drive protector of the present invention can be combined with a single-phase AC protector and installed inside the plug to form a protector plug with a leakage drive protection unit. Referring to Figure 6, insert the plug into a socket connected to a single-phase AC line , can directly drive the air switch and circuit breaker with leakage protection function to cut off the circuit for power supply faults such as overvoltage, undervoltage, and abnormal voltage formed by broken zero line, so as to obtain the purpose of protecting load 1 and/or load 2 . The circuit is simple, only one plug needs to be installed in a leakage protection circuit, the cost is low, and the utility model is widely used, especially suitable for rural electricity protection and long-distance protection.

The above are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in this within the scope of protection of the invention.

Claims (6)

1. a kind of ac leakage drives protector, include the fault detection circuit of harmonics device, which includes Multigroup contact of AC power incoming end and output terminal, every group of contact are three, are respectively the first contact（12）, second touch Point（11）With the 3rd contact（14）, the second contact（11）Inscribed switch, the switch can access the first contact（12）Or the 3rd contact （14）；Fault detection circuit is connected on alternating current source；It is characterized in that：

The ac leakage driving protector further includes electric leakage driving protection location, which includes a group relay contact And capacitance, one the first contact of relay termination of capacitance, a phase line of another termination AC power of capacitance, the second contact of relay connects The second contact of fault detection circuit（11）；First contact of fault detection circuit（12）Ground wire, fault detection circuit the Three contacts（14）For dead end；When ac power supply circuit breaks down, by phase line, capacitance, relay contact closure, fault detect The second contact of circuit output end（11）With the first contact（12）Conducting, ground wire form detection of electrical leakage driving circuit, detection of electrical leakage Driving circuit control leakage switch disconnects.

2. ac leakage according to claim 1 drives protector, it is characterized in that：The relay is attracted relay for delay Device.

3. ac leakage according to claim 1 or 2 drives protector, it is characterized in that：The electric leakage driving protection location Including two group relay contacts and capacitance, first group of relay contact and one phase line of termination of capacitance built-up circuit are another Terminate the second contact of first group of fault detection circuit output terminal, second group of relay contact and one end of capacitance built-up circuit Connect another phase line, the second contact of another second group of termination fault detection circuit output terminal.

4. ac leakage according to claim 1 or 2 drives protector, it is characterized in that：The electric leakage driving protection location Including two group relay contacts and capacitance, first group of relay contact and one phase line of termination of capacitance built-up circuit are another Terminate the second contact of first group of fault detection circuit output terminal, second group of relay contact and one end of capacitance built-up circuit Connect another phase line, the second contact of another first group of termination fault detection circuit output terminal.

5. ac leakage according to claim 1 or 2 drives protector, it is characterized in that：The fault detection circuit is electricity Press fault detection circuit or current failure detection circuit.

6. ac leakage according to claim 1 or 2 drives protector, it is characterized in that：The harmonics device is single-phase Harmonics device, the electric leakage driving protection location is installed in single phase ac protector, and single phase ac protector is made Protector plug is engaged with the socket for being installed on single phase ac circuit.