CN211088171U

CN211088171U - AC contactor for solving second flash

Info

Publication number: CN211088171U
Application number: CN201922387664.9U
Authority: CN
Inventors: 刘辉; 刘敏; 吴临红; 刘进; 刘功豪; 章旭
Original assignee: JIANGXI CRYSTAL-OPTECH CO LTD
Current assignee: JIANGXI CRYSTAL-OPTECH CO LTD
Priority date: 2019-12-26
Filing date: 2019-12-26
Publication date: 2020-07-24
Anticipated expiration: 2029-12-26

Abstract

The utility model discloses an AC contactor for solving second flash, which comprises an AC contactor body, wherein the AC contactor body is connected into a power supply line for supplying power to a load by three-phase AC; the three-phase alternating current power supply also comprises a normally open contact and a normally closed contact which are connected in series in sequence and are connected into the three-phase alternating current; the alternating current contactor comprises a main contact, a coil and a time delay contact, wherein the main contact is connected in series in a power supply line, the coil is connected in series between a normally open contact and three-phase alternating current connected with the normally open contact, and the time delay contact is connected in parallel at two ends of the normally open contact; the power supply system also comprises a restart controller powered by three-phase alternating current, wherein the restart controller is provided with a restart contact which is connected in parallel with two ends of the normally open contact; an energy accumulator for storing energy is connected to the coil. The utility model has the advantages of it is following and effect: the influence of 'second flash' of the power grid on continuous production and the influence of motor starting on a circuit can be effectively reduced.

Description

AC contactor for solving second flash

Technical Field

The utility model relates to a power electronics field, in particular to an ac contactor for solving second flash.

Background

The 'second flashing' of the power grid is a problem which often occurs in the quality of electric energy, a plurality of factories experience similar to the 'second flashing' power failure, the reasons are various, the national power grid completely stops the power grid, and only protective measures can be taken to reduce the occurrence frequency. The common phenomena causing 'second flash' of the power grid are as follows:

1. electrical power systems are subject to unexpected lightning strikes;

2. the power grid is touched by animals and foreign objects, and the line short circuit fault is caused by natural disaster environment factors;

3. the phenomenon of sudden change of voltage and current caused by the action of an electric switch of a high-voltage load and the switching of power supply faults;

4. electrostatic electromagnetic interference false operation, discharge and harmonic wave influence relay protection and automatic devices are generated in the operation of equipment;

5. starting an induction motor of the electrical equipment and switching the capacitor bank;

the above-mentioned faults cause instantaneous power failure or sudden rise of voltage and current, i.e. "second flash". The fusion of the grid voltage is mainly characterized in that the fusion of the grid voltage can not be completely avoided in the existing power system, and the occurrence probability is far higher than that of complete power failure. At present, when a company frequency conversion air compressor, a water pump with frequency conversion control, production coating equipment and the like are in 'flash seconds' of a power grid, the phenomenon of alarm shutdown can occur to different degrees, and the phenomenon is particularly prominent in thunderstorm seasons. The short-time voltage fluctuation range of the power grid exceeds the normal range value, so that the short-time power-off and shutdown of the electrical equipment are caused.

The alternating current contactor is used as an actuating element and is used for switching on and switching off a line or frequently controlling the running of equipment such as a motor and the like; for a general AC contactor, when the voltage of the AC contactor is reduced to 45%, the coil is released for 20-30 ms, the AC electromagnetic valve is released for 30-40 ms, and the control equipment is closed for 20 ms. In order to avoid the release of such ac contactors during grid 'second flashes', there is a need in the market for a re-activatable ac contactor.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing an ac contactor for solving second flash, can effectively reduce because of the influence and the motor start to the circuit of electric wire netting 'second flash' to carrying out the continuity of production.

The above technical purpose of the present invention can be achieved by the following technical solutions: an alternating current contactor for solving the second flash phenomenon comprises an alternating current contactor body, wherein the alternating current contactor body is connected into a power supply line for supplying power to a load by three-phase alternating current and is used for controlling the cut-off or conduction state of the power supply line; the three-phase alternating current power supply also comprises a normally open contact and a normally closed contact which are connected in series in sequence and are connected into the three-phase alternating current; the alternating current contactor comprises a main contact, a coil and a time delay contact, wherein the main contact is connected in series in a power supply line, the coil is connected in series between a normally open contact and three-phase alternating current connected with the normally open contact, and the main contact can be closed to realize the conduction of the power supply line when the coil is electrified; the delay contacts are connected in parallel at two ends of the normally open contact; the power supply system also comprises a restart controller powered by three-phase alternating current, wherein the restart controller is provided with a restart contact which is connected in parallel with two ends of the normally open contact; and the coil is connected with an energy storage device for storing energy.

The energy accumulator is a capacitor or a time delay relay.

The power supply line is further provided with a thermal relay for overheat protection in series.

The power supply line is further provided with a fuse protector for overcurrent protection in series.

The power supply line is further provided with a relay which plays a role in isolation in series.

It is further provided that the load is an electric motor.

The utility model has the advantages that:

1. when the motor as the load loses power, the AC contactor keeps the main contact in a closed state within a certain time. If the fault is 'second flashing' of the power grid, a self-protection loop is formed by restarting the controller after power supply is recovered, and the motor is restarted; and if the fault is a permanent fault, delaying the disconnection. According to the alternating current contactor, internal energy storage can be completed through the energy storage device, and stored electric energy is released when a power grid flashes for a second time, so that tripping of a coil is delayed. When the 'second flash' of the power grid occurs, the restart controller detects the voltage and restores the released low voltage to be normal within a set time, the restart contact is closed, the coil is electrified, and the motor is restarted. Therefore, the influence of the 'second flash' of the power grid on continuous production and the influence of motor starting on a circuit can be effectively reduced.

2. The energy accumulator can play a role in storing electric energy and releasing electric energy so as to delay the tripping time of the coil.

3. The thermal relay has a protection function, and when the heating value caused by overcurrent is increased, the thermal relay can control the power supply circuit to be disconnected, so that the overload protection of the motor is realized.

4. The fuse has a further protection function, and when the current exceeds a specified value, the fuse body is fused by heat generated by the fuse body to disconnect a power supply line and protect the motor.

5. The relay also has a protection function and plays a role in isolation; the motor is further protected by electrical isolation across the relay.

Drawings

Fig. 1 is a schematic structural diagram of the embodiment.

In the figure: 11. a normally closed contact; 12. a normally open contact; 21. a main contact; 22. a coil; 23. A time delay contact; 31. restarting the controller; 32. then starting the contact; 4. an energy storage device; 51. A load; 52. a thermal relay; 53. a fuse; 54. a relay; 55. three-phase alternating current.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

Referring to fig. 1, an ac contactor for solving the second flash phenomenon includes an ac contactor body which is inserted into a power supply line for supplying power to a load 51 by three-phase ac power 55 and controls a cut-off or conduction state of the power supply line; the three-phase alternating current power supply also comprises a normally open contact 12 and a normally closed contact 11 which are connected in series and connected into the three-phase alternating current 55; the normally open contact 12 and the normally closed contact 11 are self-locking switches, such as single-pole switches.

The alternating current contactor comprises a main contact 21, a coil 22 and a time delay contact 23, wherein the main contact 21 is connected in series in a power supply line, the coil 22 is connected in series between the normally open contact 12 and a three-phase alternating current 55 connected with the normally open contact, and when the coil 22 is electrified, the main contact 21 can be closed to realize the conduction of the power supply line; the delay contacts 23 are connected in parallel at two ends of the normally open contact 12; it should be understood that the ac contactor works on the principle that when the coil 22 is energized, the current of the coil 22 generates a magnetic field, and the internal static iron core generates an electromagnetic attraction force to attract the moving iron core and drive the main contact 21 to close. The arrangement of the delay contact 23 can ensure that the delay contact 23 is not immediately disconnected due to power failure when the power grid flashes for a second time, and the coil 22 is continuously conducted for a period of time; of course, the delay contact 23 may be a contact of a delay relay, and may perform a delay function.

The starter controller 31 is powered by three-phase alternating current 55, the starter controller 31 is provided with a starter contact 32, and the starter contact 32 is connected in parallel with two ends of the normally open contact 12; when the 'second flash' of the power grid occurs, the restart controller 31 detects the voltage and restores the released low voltage to normal within a set time, the restart contact 32 is closed, the coil 22 is electrified, and the motor is restarted.

An energy accumulator 4 for storing energy is connected to the coil 22.

Further, the energy storage 4 is a capacitor or a time delay relay, which plays a role of storing electric energy and releasing electric energy, so that when the 'second flash' occurs in the power grid, the stored electric energy is released, thereby delaying the tripping of the coil 22.

When the motor as the load 51 loses power, the ac contactor keeps the main contact 21 in a closed state for a certain period of time. If the fault is 'second flashing' of the power grid, a self-protection loop is formed by the restarting controller 31 after power supply is recovered, and the motor is restarted; and if the fault is a permanent fault, delaying the disconnection. According to the alternating current contactor, internal energy storage can be completed through the energy storage device 4, and when a power grid flashes for a second time, stored electric energy is released, so that the delay coil 22 is tripped. When the 'second flash' of the power grid occurs, the restart controller 31 detects the voltage and restores the released low voltage to normal within a set time, the restart contact 32 is closed, the coil 22 is electrified, and the motor is restarted. Therefore, the influence of the 'second flash' of the power grid on continuous production and the influence of motor starting on a circuit can be effectively reduced.

For more convenient review by workers in the electronics field, corresponding electrical symbols are labeled on the various elements in fig. 1; specifically, the normally closed contact 11 is SB1, the normally open contact 12 is SB2, the main contact 21 is KM1, the coil 22 is KM2(a1 and a2 are both ends of the coil 22, and energy is stored by the A3 energy storage device 4), the delay contact 23 is KM3, the restart contact 32 is ZDK, the thermal relay 52 is FR, the fuse 53 is FU, the relay 54 is QF, and the three-phase alternating current 55 is R, S, T, respectively.

Further, a thermal relay 52 for overheat protection is connected in series to the power supply line.

Further, a fuse 53 for overcurrent protection is connected in series to the power supply line.

A relay 54 for isolation is connected in series with the further power supply line.

The further load 51 is an electric motor.

The thermal relay 52, the fuse 53, and the relay 54 are commercially available products, and may be purchased directly from the market. In practical application, the alternating current contactor can be matched with the characteristics of the motor to complete frequent starting and stopping actions, so that the alternating current contactor is very suitable for the motor to use.

The present embodiment is only for explaining the present invention, and it is not limited to the present invention, and those skilled in the art can make modifications to the present embodiment without inventive contribution as required after reading the present specification, but all of them are protected by patent laws within the scope of the claims of the present invention.

Claims

1. An AC contactor for solving the second flash phenomenon comprises an AC contactor body, wherein the AC contactor body is connected into a power supply line for supplying power to a load (51) by three-phase alternating current (55) and is used for controlling the cut-off or conduction state of the power supply line; the three-phase alternating current transformer further comprises a normally open contact (12) and a normally closed contact (11) which are connected in series and connected into the three-phase alternating current (55); the method is characterized in that:

the alternating current contactor comprises a main contact (21), a coil (22) and a time delay contact (23), wherein the main contact (21) is connected in series in a power supply line, the coil (22) is connected in series between a normally open contact (12) and a three-phase alternating current (55) connected with the normally open contact, and when the coil (22) is electrified, the main contact (21) can be closed to realize the conduction of the power supply line; the delay contacts (23) are connected in parallel at two ends of the normally open contact (12);

the starter is characterized by further comprising a restart controller (31) powered by three-phase alternating current (55), wherein the restart controller (31) is provided with a restart contact (32), and the restart contact (32) is connected to two ends of the normally open contact (12) in parallel;

the coil (22) is connected with an energy storage device (4) for storing energy.

2. An ac contactor for solving second flash according to claim 1, wherein: the energy accumulator (4) is a capacitor or a time delay relay.

3. An ac contactor for solving second flash according to claim 1, wherein: and a thermal relay (52) for overheat protection is connected in series on the power supply line.

4. An ac contactor for solving second flash according to claim 1, wherein: and a fuse (53) for overcurrent protection is connected in series on the power supply line.

5. An ac contactor for solving second flash according to claim 1, wherein: and a relay (54) with an isolating function is connected in series on the power supply line.

6. An ac contactor for solving second flash according to claim 1, wherein: the load (51) is an electric motor.