CN219611340U

CN219611340U - Trip circuit with automatic adjustment and maintenance functions

Info

Publication number: CN219611340U
Application number: CN202223555776.9U
Authority: CN
Inventors: 张杭; 陈国富
Original assignee: Nanjing Intelligent Apparatus Co ltd
Current assignee: Nanjing Intelligent Apparatus Co ltd
Priority date: 2022-12-29
Filing date: 2022-12-29
Publication date: 2023-08-29
Anticipated expiration: 2032-12-29

Abstract

The utility model discloses a tripping circuit capable of automatically adjusting a holding function according to a circuit current, which comprises a tripping circuit and a breaker operating mechanism connected in series with the tripping circuit, wherein a tripping contact is connected in series with the breaker operating mechanism through a holding relay coil, a normally open contact of a holding relay is connected in parallel with the tripping contact, a self-recovery fuse PPTC is connected in parallel with the holding relay coil, two groups of diodes are connected in parallel at two ends of the holding relay coil, the two groups of diodes are connected in reverse parallel again, and the working voltage of the holding relay is provided through the voltage drop of the diodes when the circuit is conducted; the utility model can solve the contact erosion phenomenon caused by the direct pull-off of the circuit current by the contact of the tripping relay in the existing tripping circuit, and can also ensure the mechanism refusing action caused by the reduction of the operating voltage of the operating mechanism due to the voltage drop of the holding relay when the circuit operating voltage is smaller.

Description

Trip circuit with automatic adjustment and maintenance functions

Technical Field

The utility model relates to the technical field of power systems, in particular to a tripping circuit capable of automatically adjusting a holding function in an operation circuit.

Background

Existing power system trip circuits typically drive the trip mechanism directly by a trip relay or by an operating circuit with a hold function. The tripping relay with large contact capacity is selected in the former, so that the cost is high and the volume is large; the problem of the contact capacity of the tripping relay can be solved, but the positive and negative of an operation power supply is required to be connected reversely during wiring, a loop is kept to be inoperative after the connection reversely, the early-stage opening and closing operation is still normal, the contact is not easy to find, the contact is ablated after long-term operation, and the operation loop fails; in addition, in the field where the operating circuit voltage is low, the voltage of the operating mechanism at the rear end is reduced due to the fact that the circuit voltage is kept to be divided, and occasional phenomena of operation failure are caused.

Disclosure of Invention

In order to solve the above problems, the object of the present utility model is: the method can solve the problem of contact ablation caused by direct pull-off of a circuit current by a tripping relay contact in the existing tripping circuit; the trip circuit of mechanism refusal caused by the reduction of the operating voltage of the operating mechanism due to the voltage drop of the holding relay can be ensured when the operating voltage of the circuit is smaller.

In order to achieve the above purpose, the technical scheme adopted by the utility model is as follows: a trip circuit for automatically adjusting hold functions comprising a trip circuit and a circuit breaker operating mechanism in series with said trip circuit, characterized by: the tripping circuit consists of a tripping contact TJ, a holding relay (TBJ ) and diodes (D1, D2, D3, D4), and a self-recovery fuse PPTC, wherein the tripping contact TJ is connected in series with the breaker operating mechanism through a coil of the holding relay TBJ, a normally open contact of the holding relay TBJ is connected in parallel with the tripping contact TJ, the self-recovery fuse PPTC is connected in parallel with a coil of the holding relay TBJ, two groups of diodes (D1, D2, D3, D4) are connected in parallel with two ends of the coil of the holding relay TBJ, the diode D1 is connected in series with the diode D2, the diode D3 is connected in series with the diode D4, the two groups of diodes are connected in reverse parallel, and the operating voltage of the coil of the holding relay TBJ is provided through the voltage drops of the diodes (D1, D2, D3, D4) when the circuit is conducted; the breaker operating mechanism comprises a normally-closed contact DL and a tripping coil TQ, wherein the normally-closed contact DL is connected with the tripping coil TQ in series and then is connected with an external direct-current power supply.

The on current of the self-recovery fuse PPTC is 0-200 mA, and the maximum current is 40A.

The coil of the holding relay TBJ is bidirectionally powered, and the working voltage of the coil is DC1.4V; the voltage drop of the diode is 2 x 0.7v.

The working principle of the utility model is as follows: the on current of the self-recovery fuse PPTC is 0-200 mA, and when the current is small, the tripping circuit does not work and is directly disconnected by the contact of the holding relay TBJ; when the current exceeds 200mA, the self-recovery fuse PPTC is disconnected in high resistance, the coil voltage of the holding relay TBJ is divided by two diodes to provide a 1.4V working power supply, the contact of the holding relay TBJ is closed, no breaking current is generated when the tripping contact TJ is separated, and the tripping contact TJ can be effectively protected; the maximum current of the self-recovery fuse PPTC is 40A, after the normally closed contact DL is separated, the coil of the holding relay TBJ is powered down, the contact of the holding relay TBJ is separated, and the self-recovery fuse PPTC is recovered.

Compared with the prior art, the utility model has the beneficial effects that:

the tripping circuit provided by the utility model can solve the problem of contact erosion caused by direct pull-off of the circuit current by the tripping relay contact in the existing tripping circuit, and also can ensure that the mechanism is refused to operate due to the reduction of the operating voltage of an operating mechanism caused by the voltage drop of a holding relay when the operating voltage of the circuit is smaller, thereby greatly reducing the damage rate of field equipment and reducing the comprehensive cost of a company.

Drawings

Fig. 1 is a schematic diagram of the trip circuit of the present utility model with an automatic hold adjustment function.

Fig. 2 is a schematic diagram of the trip circuit of the automatic hold adjustment function of the present utility model in terms of operating moments.

Detailed Description

For a better understanding of the present utility model, reference will now be made to the following description of the utility model taken in conjunction with the accompanying drawings and specific examples.

Fig. 1 is a schematic diagram of the structure of a trip circuit of the present utility model with automatic hold adjustment, comprising a trip circuit and a circuit breaker operating mechanism connected in series with said trip circuit, characterized in that: the tripping circuit consists of a tripping contact TJ, a holding relay (TBJ ), diodes (D1, D2, D3, D4) and a self-recovery fuse PPTC, wherein the tripping contact TJ is connected with the breaker operating mechanism in series through a coil of the holding relay TBJ, a normally open contact of the holding relay TBJ is connected with the tripping contact TJ in parallel, the self-recovery fuse PPTC is connected with a coil of the holding relay TBJ in parallel, two groups of diodes (D1, D2, D3 and D4) are connected at two ends of the coil of the holding relay TBJ in parallel, the diode D1 is connected with the diode D2 in series, the diode D3 is connected with the diode D4 in series, the two groups of diodes are connected in reverse parallel again, and the operating voltage of the coil of the holding relay TBJ is provided through the voltage drops of the diodes (D1, D2, D3 and D4) when the circuit is conducted; the breaker operating mechanism comprises a normally-closed contact DL and a tripping coil TQ, wherein the normally-closed contact DL is connected with the tripping coil TQ in series and then is connected with an external direct-current power supply.

Fig. 2 is a schematic diagram of the moment of action of the trip circuit of the automatic adjustment and hold function according to the present utility model, according to which the implementation of the utility model is described:

when the front end of the TJ is connected with the operating power DC+, and the rear end of the operating mechanism is connected with the DC-.

When the permanent magnet mechanism is used, the general operation voltage is DC24V, the current of an operation loop is smaller and lower than 200mA, the self-recovery fuse PPTC is conducted, the two ends of a coil of the relay TBJ are kept to be pressureless, a voltage divider is not arranged in the loop, the voltage of the permanent magnet operation mechanism is 24V, and the reliable action of the mechanism is ensured; during breaking, the circuit current is small, so that the contact of the holding relay TBJ can be directly broken, and the contact cannot be damaged.

When the self-recovery fuse is used for a spring operating mechanism, the operating voltage is higher, the loop current is also larger, the self-recovery fuse PPTC is disconnected in high resistance, the diode D1/D2 is conducted, the voltage is divided by 1.4V to the coil of the holding relay TBJ, the contact of the holding relay TBJ acts, the loop is held and the tripping contact TJ is waited to be separated, and at the moment, the tripping contact TJ does not need to break the current because the coil of the holding relay TBJ is conducted.

The operating voltage of the spring operating mechanism is higher, two diodes are connected in series in the loop, the voltage of the operating mechanism is only 1.4V lower than the operating voltage, and the action of the mechanism is not influenced.

When the front end of the tripping contact TJ is connected with an operating power supply DC-, and the rear end of the operating mechanism is connected with DC+, the coil voltage of the holding relay TBJ is provided by the on voltage of the diode D3/D4, and as the coil of the holding relay TBJ is bidirectionally powered, the loop works normally and the action process is the same as the above.

The embodiment realizes the loop composition and the working principle of the utility model, can effectively reduce the equipment damage rate and reduce the comprehensive cost.

The present utility model has been described in terms of the preferred embodiments thereof, and it should be understood by those skilled in the art that various modifications can be made without departing from the principles of the utility model, and such modifications should also be considered as being within the scope of the utility model.

Claims

1. A trip circuit for automatically adjusting hold functions comprising a trip circuit and a circuit breaker operating mechanism in series with said trip circuit, characterized by: the tripping circuit consists of a tripping contact TJ, a holding relay TBJ, diodes and a self-recovery fuse PPTC, wherein the tripping contact TJ is connected in series with the breaker operating mechanism through a coil of the holding relay TBJ, a normally open contact of the holding relay TBJ is connected in parallel with the tripping contact TJ, the self-recovery fuse PPTC is connected in parallel with a coil of the holding relay TBJ, two groups of diodes are connected in parallel at two ends of the coil of the holding relay TBJ, one group of diodes comprises a diode D1 and a diode D2 which are connected in series, the other group of diodes comprises a diode D3 and a diode D4 which are connected in series, the two groups of diodes are connected in reverse parallel again, and the operating voltage of the holding relay TBJ is provided through the voltage drop of the diodes when the circuit is conducted; the breaker operating mechanism comprises a normally-closed contact DL and a tripping coil TQ, wherein the normally-closed contact DL is connected with the tripping coil TQ in series and then is connected with an external direct-current power supply.

2. The trip circuit of claim 1, wherein the trip circuit automatically adjusts the hold function: the on current of the self-recovery fuse PPTC is 0-200 mA, and the maximum current is 40A.

3. The trip circuit of claim 1, wherein the trip circuit automatically adjusts the hold function: the hold relay TBJ supplies power in both directions, and the coil operating voltage is DC1.4V.

4. The trip circuit of claim 1, wherein the trip circuit automatically adjusts the hold function: the voltage drop of the diode is 2 x 0.7v.

5. A trip circuit for automatically adjusting a hold function according to any one of claims 1-4 wherein: the on current of the self-recovery fuse PPTC is 0-200 mA, and when the current is small, a tripping circuit does not work and is directly disconnected by the contact of the holding relay TBJ; when the current exceeds 200mA, the self-recovery fuse PPTC is disconnected in high resistance, the coil voltage of the holding relay TBJ is divided by two diodes to provide a 1.4V working power supply, the contact of the holding relay TBJ is closed, no breaking current is generated when the tripping contact TJ is separated, and the tripping contact TJ can be effectively protected; the maximum current of the self-recovery fuse PPTC is 40A, after the auxiliary contact DL of the circuit breaker is separated, the coil of the holding relay TBJ is powered down, the contact of the holding relay TBJ is separated, and the self-recovery fuse PPTC is recovered.