A circuit breaker close / open trip full operating condition monitoring operating circuit

Abstract

The application relates to a circuit breaker closing / opening full-condition monitoring operation circuit, which improves the circuit by adding elements, and provides element selection and parameter setting basis, analyzes the operation state of the circuit breaker opening / closing circuit, and realizes full-condition monitoring, broken line branch identification and circuit protection of the opening / closing circuit.

Description

Technical Field

[0001] The invention belongs to the field of power protection, relates to a relay, and in particular to a circuit breaker closing / tripping full-working-condition monitoring operation circuit. Background Art

[0002] Circuit breakers are critical power devices driven by protection to isolate faulty components, playing a dual role of protection and control in power systems. Improper circuit breaker operation can trigger or expand power grid accidents, even leading to power system collapse and significant economic losses. In addition to faults in the circuit breaker itself, improper circuit breaker operation can also be caused by faults in the operating circuit that controls the circuit breaker's tripping and closing operations. The operating circuit connects the protection device to the circuit breaker and primarily consists of several relays, their contacts, and the secondary cables connecting the various components. Contact adhesion and circuit breakage are the most common faults in the operating circuit and are among the primary causes of improper protection system operation.

[0003] Conventional methods of directly monitoring the operating circuit using a traffic light circuit or indirectly monitoring the operating circuit using a position relay's normally closed contacts in series with a signal circuit fail to monitor the closing circuit after the circuit breaker is closed, nor the tripping circuit after it has tripped. This DC operating circuit only continuously monitors the DC operating power supply and cannot meet the requirement for continuous monitoring of the tripping / closing circuit under all operating conditions. Furthermore, the operating circuit break monitoring circuit will issue the same alarm signal regardless of whether a line break occurs in the tripping or closing circuit. Therefore, traditional methods cannot specifically identify the branch experiencing a line break. Finally, if the circuit breaker's auxiliary contacts QF2 or QF1 fail to open the tripping / closing circuit due to contact sticking or refusal to operate after the circuit breaker completes the tripping / closing operation, the closed contacts of the circuit's self-latch relays TBJ and HBJ cause the tripping / closing circuit to remain conductive after the circuit breaker completes the operation. If this conductive state persists for an extended period, components within the circuit, particularly the opening / closing coil, will overheat and burn out, leading to circuit disconnection. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings of the existing technology, improve the circuit by adding components in the circuit breaker operation circuit and provide a basis for component selection and parameter setting, analyze the operating status of the circuit breaker trip / closing circuit, and realize full working condition monitoring of the trip / closing circuit, broken branch identification and circuit protection.

[0005] The present invention solves the technical problem by the following technical solutions:

[0006] A circuit breaker closing / tripping full-condition monitoring operation circuit, characterized in that: the operation circuit includes two types: a closing circuit and a tripping circuit;

[0007] In the closing circuit, the normally open contact HTJ1 of the closing time relay, the automatic closing contact ZHJ and the manual closing contact SHJ are connected in parallel, and then connected in series with the closing time relay HTJ, the anti-trip relay contact TTJ3, the delayed normally closed contact HTJ2 of the closing time relay, the cable, the normally closed auxiliary contact QF1 of the circuit breaker and the closing coil HQ. The closing position relay HWJ is connected in parallel with the normally closed auxiliary contact QF1 of the circuit breaker. One end of the closing line break monitoring relay HDJJ is connected to the DC operating power supply, and the other end is connected to the closing coil via the cable and the normally closed auxiliary contact QF1 of the circuit breaker.

[0008] After the normally open contact TTJ1 of the trip time relay, the automatic trip contact ZTJ and the manual trip contact STJ in the trip circuit are connected in parallel, they are connected in series with the trip time relay TTJ, the trip time relay delayed normally closed contact TTJ2, the cable, the circuit breaker normally open auxiliary contact QF2 and the trip coil TQ in sequence. The trip position relay TWJ is connected in parallel with the circuit breaker normally open auxiliary contact QF2. One end of the trip line break monitoring relay TDJJ is connected to the DC operating power supply, and the other end is connected to the trip coil via the cable and the circuit breaker normally open auxiliary contact QF2.

[0009] Moreover, the closing line break monitoring relay HDJJ, cable, closing position relay HWJ and closing coil HQ are connected in series in sequence to form a line break monitoring branch after the closing circuit is closed; the closing line break monitoring relay HDJJ, cable, circuit breaker normally closed auxiliary contact QF1 and closing coil HQ are connected in series in sequence to form a monitoring branch after the closing circuit trips. The above two monitoring branches together constitute the full working condition monitoring of the closing circuit.

[0010] Moreover, the tripping line break monitoring relay TDJJ, cable, tripping position relay TWJ and tripping coil TQ are connected in series in sequence to form a line break monitoring branch after the tripping circuit trips; the tripping line break monitoring relay TDJJ, cable, circuit breaker normally open auxiliary contact QF2 and tripping coil TQ are connected in series in sequence to form a monitoring branch after the tripping circuit is closed. The above two monitoring branches together constitute the full working condition monitoring of the tripping circuit.

[0011] The advantages and beneficial effects of the present invention are:

[0012] 1. The circuit breaker closing / tripping full-condition monitoring operation circuit of the present invention improves the existing tripping / closing circuit and provides a basis for selecting components and setting parameters in the circuit. It can realize full-condition monitoring of the tripping / closing circuit, that is, the tripping / closing circuit can always be monitored regardless of whether the circuit breaker is in the closed position or the tripping position.

[0013] 2. The circuit breaker closing / tripping full-condition monitoring operation circuit of the present invention has an added time relay delay contact that can realize the protection of the tripping / closing circuit, avoiding the long-term conduction of the tripping / closing circuit due to the adhesion or refusal of the circuit breaker auxiliary contacts, thereby avoiding the burning of components.

[0014] 3. The circuit breaker closing / tripping full-condition monitoring operation circuit of the present invention has an improved tripping / closing circuit that can identify a broken branch, that is, it can independently monitor whether the closing circuit or the tripping circuit is broken. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 1 is a schematic diagram of the improved closing circuit structure in an embodiment of the present invention;

[0016] Figure 2 2 is a schematic diagram of the improved tripping circuit structure in an embodiment of the present invention.

[0017] Description of Reference Numerals

[0018] Automatic closing contact ZHJ; manual closing contact SHJ; closing time relay HTJ; anti-tripping relay contact TTJ3; closing time relay normally open contact HTJ1; closing time relay delayed normally closed contact HTJ2; closing line break monitoring relay HDJJ; circuit breaker normally closed auxiliary contact QF1; closing position relay HWJ; closing coil HQ; automatic tripping contact ZTJ; manual tripping contact STJ; tripping time relay TTJ; tripping time relay normally open contact TTJ1; tripping time relay delayed normally closed contact TTJ2; tripping line break monitoring relay TDJJ; circuit breaker normally open auxiliary contact QF2; tripping position relay TWJ; tripping coil TQ. DETAILED DESCRIPTION

[0019] The present invention will be further described in detail below through specific examples. The following examples are only illustrative and not restrictive, and the scope of protection of the present invention cannot be limited thereto.

[0020] A circuit breaker closing / tripping full-operating condition monitoring operation circuit is characterized in that the operation circuit includes two types: a closing circuit and a tripping circuit.

[0021] like Figure 1 As shown, the specific structure of the improved closing circuit of the present invention is as follows:

[0022] (1) After the normally open contact HTJ1 of the closing time relay, the automatic closing contact ZHJ and the manual closing contact SHJ in the closing circuit are connected in parallel, they are connected in series with the closing time relay HTJ, the anti-trip relay contact TTJ3, the delayed normally closed contact HTJ2 of the closing time relay, the cable, the normally closed auxiliary contact QF1 of the circuit breaker and the closing coil HQ in sequence. The closing position relay HWJ is connected in parallel with the normally closed auxiliary contact QF1 of the circuit breaker. One end of the closing line break monitoring relay HDJJ is connected to the DC operating power supply, and the other end is connected to the closing coil through the cable and the normally closed auxiliary contact QF1 of the circuit breaker.

[0023] (2) The closing disconnection monitoring relay HDJJ, the cable, the closing position relay HWJ, and the closing coil HQ are connected in series to form the disconnection monitoring branch after the closing circuit is closed. The closing disconnection monitoring relay HDJJ, the cable, the circuit breaker normally closed auxiliary contact QF1, and the closing coil HQ are connected in series to form the monitoring branch after the closing circuit trips. The above two monitoring branches together constitute the full working condition monitoring of the closing circuit.

[0024] (3) The normally open contact HTJ1 of the closing time relay can meet the self-holding requirements of the closing action; the delayed normally closed contact HTJ2 of the closing time relay can normally cut off the closing circuit after the circuit breaker closing operation is completed, and at the same time prevent the normally closed auxiliary contact QF1 of the circuit breaker from being burned due to the long-term flow of operating current in the refusal circuit components, thereby realizing the protection of the closing circuit.

[0025] (4) The closing position relay HWJ can only be turned on after the circuit breaker is closed, and its contact status can reflect whether the circuit breaker is currently in the closing position.

[0026] like Figure 2 As shown, the specific structure of the improved tripping circuit of the present invention is as follows:

[0027] (1) After the normally open contact TTJ1 of the tripping time relay, the automatic tripping contact ZTJ and the manual tripping contact STJ in the tripping circuit are connected in parallel, they are connected in series with the tripping time relay TTJ, the normally closed contact TTJ2 of the tripping time relay delay, the cable, the normally open auxiliary contact QF2 of the circuit breaker and the tripping coil TQ in sequence. The tripping position relay TWJ is connected in parallel with the normally open auxiliary contact QF2 of the circuit breaker. One end of the tripping line break monitoring relay TDJJ is connected to the DC operating power supply, and the other end is connected to the tripping coil via the cable and the normally open auxiliary contact QF2 of the circuit breaker.

[0028] (2) The tripping line monitoring relay TDJJ, the cable, the tripping position relay TWJ, and the tripping coil TQ are connected in series to form a line monitoring branch after the tripping circuit is tripped. The tripping line monitoring relay TDJJ, the cable, the normally open auxiliary contact QF2 of the circuit breaker, and the tripping coil TQ are connected in series to form a monitoring branch after the tripping circuit is closed. The above two monitoring branches together constitute the full working condition monitoring of the tripping circuit.

[0029] (3) The normally open contact TTJ1 of the tripping time relay can meet the self-holding requirements of the tripping action; the normally closed contact TTJ2 of the tripping time relay can normally cut off the tripping circuit after the circuit breaker tripping operation is completed. At the same time, it can prevent the circuit components from burning due to the long-term flow of operating current when the normally open auxiliary contact QF2 of the circuit breaker refuses to operate, thereby realizing the protection of the tripping circuit.

[0030] (4) The trip position relay TWJ can only be turned on after the circuit breaker trips, and its contact status can reflect whether the circuit breaker is currently in the trip position.

[0031] When selecting a time relay, consider the relay's contact capacity and setting time. To ensure that the trip / close time relay's delayed contacts can interrupt the trip / close circuit current after the trip / close operation is complete, choose a relay with a large contact capacity. The time relay's setting time should be slightly longer than the circuit breaker's trip / close time to ensure reliable circuit breaker operation.

[0032] Taking the closing circuit as an example, to prevent the closing coil from burning out due to long-term conduction, the internal resistance of the closing wire break monitoring relay HDJJ should be relatively high. Furthermore, to ensure that the time relay's delayed contacts can cut off the closing circuit current after the closing operation is complete, the closing position relay HWJ is required to limit the current. Therefore, the closing position relay HWJ should also be relatively large. To facilitate the selection of the closing position relay HWJ, a relay with the same design as the closing wire break monitoring relay HDJJ is selected. Therefore, the requirements for the closing position relay HWJ are as follows:

[0033] (1) In order to prevent the trip / close circuit from being on for a long time and causing the trip / close coil to burn out, the current passing through the trip / close coil should not be greater than its long-term thermal stability current. Assume that the long-term thermal stability current of the trip / close coil is I s , then R w Should meet

[0034] (2) In order for the time relay delay contact to cut off the closing circuit current after the closing operation is completed, the current passing through the closing circuit after the closing operation is completed should be less than the maximum current that the contact can cut off. Assume that the maximum current that the time relay contact can cut off is I cut , then R w Should meet

[0035] (3) In order to monitor the trip / close circuit using the contact status of the closing / breaking monitoring relay HDJJ and the closing position relay HWJ, the current passing through the relay should be greater than its starting current. Assume that the starting current of the relay is I q , then R w Should meet

[0036] where R c Indicates the resistance of the closing coil HQ, R w Indicates the internal resistance of the closing and disconnection monitoring relay HDJJ or the closing position relay HWJ, R t Indicates the internal resistance of the closing time relay HTJ.

[0037] Although the embodiments and drawings of the present invention are disclosed for illustrative purposes, those skilled in the art will understand that various substitutions, changes and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments and drawings.

Claims

1. A circuit breaker closing / tripping full-condition monitoring operation circuit, characterized by: The operating circuit includes two types: closing circuit and tripping circuit; In the closing circuit, the normally open contact HTJ1 of the closing time relay, the automatic closing contact ZHJ and the manual closing contact SHJ are connected in parallel, and then connected in series with the closing time relay HTJ, the anti-trip relay contact TTJ3, the delayed normally closed contact HTJ2 of the closing time relay, the cable, the normally closed auxiliary contact QF1 of the circuit breaker and the closing coil HQ. The closing position relay HWJ is connected in parallel with the normally closed auxiliary contact QF1 of the circuit breaker. One end of the closing line break monitoring relay HDJJ is connected to the DC operating power supply, and the other end is connected to the closing coil via the cable and the normally closed auxiliary contact QF1 of the circuit breaker. In the tripping circuit, the normally open contact TTJ1 of the tripping time relay, the automatic tripping contact ZTJ and the manual tripping contact STJ are connected in parallel, and then connected in series with the tripping time relay TTJ, the normally closed contact TTJ2 of the tripping time relay delay, the cable, the normally open auxiliary contact QF2 of the circuit breaker and the tripping coil TQ in sequence. The tripping position relay TWJ is connected in parallel with the normally open auxiliary contact QF2 of the circuit breaker. One end of the tripping line break monitoring relay TDJJ is connected to the DC operating power supply, and the other end is connected to the tripping coil via the cable and the normally open auxiliary contact QF2 of the circuit breaker; The closing and disconnection monitoring relay HDJJ, cable, closing position relay HWJ and closing coil HQ are connected in series in sequence to form a disconnection monitoring branch after the closing circuit is closed; the closing and disconnection monitoring relay HDJJ, cable, circuit breaker normally closed auxiliary contact QF1 and closing coil HQ are connected in series in sequence to form a monitoring branch after the closing circuit trips. The above two monitoring branches together constitute full-condition monitoring of the closing circuit; The tripping line break monitoring relay TDJJ, the cable, the tripping position relay TWJ and the tripping coil TQ are sequentially connected in series to form a line break monitoring branch after the tripping circuit trips; the tripping line break monitoring relay TDJJ, the cable, the circuit breaker normally open auxiliary contact QF2 and the tripping coil TQ are sequentially connected in series to form a monitoring branch after the tripping circuit is closed. The above two monitoring branches together constitute a full-condition monitoring of the tripping circuit; The requirements for the closing position relay HWJ are: In order to prevent the trip / close circuit from being on for a long time and causing the trip / close coil to burn out, the current passing through the trip / close coil should not be greater than its long-term thermal stability current. Assume that the long-term thermal stability current of the trip / close coil is I s , then R w Should meet In order for the time relay delay contact to cut off the closing circuit current after the closing operation is completed, the current passing through the closing circuit should be less than the maximum current that the contact can cut off. Assuming that the maximum current that the time relay contact can cut off is I cut , then R w Should meet In order to monitor the trip / close circuit using the contact status of the closing / breaking monitoring relay HDJJ and the closing position relay HWJ, the current passing through the relay should be greater than its starting current. Assume that the starting current of the relay is I q , then R w Should meet Where: R c Indicates the resistance of the closing coil HQ, R w Indicates the internal resistance of the closing and disconnection monitoring relay HDJJ or the closing position relay HWJ, R t Indicates the internal resistance of the closing time relay HTJ.

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