Control circuit for locking secondary circuit of motor comprehensive protection device

Abstract

The utility model discloses a control circuit for locking a secondary circuit of a motor comprehensive protection device, and relates to the technical field of power systems, and the circuit comprises a power supply positive electrode, a power supply negative electrode, a motor protection device, a circuit breaker switching-on locking circuit, a switching-on circuit, a tripping circuit and a protection circuit. The circuit breaker closing locking loop comprises a locking electromagnet and a normally-closed auxiliary contact of a third intermediate relay. The closing loop comprises a closing coil, a DCS closing relay, a closing button and a first connecting contact of the motor protection device; the tripping loop comprises a tripping coil, a circuit breaker closing state signal normally open auxiliary contact, an opening button, a DCS opening relay and a second connecting contact of the motor protection device; the protection loop includes a coil of the third intermediate relay and a protection output node of the motor protection device. The motor protection device locking device can replace a software program or realize locking of the motor protection device by means of a DCS control system, cost is saved, the transformation work amount is small, and the later failure rate is effectively reduced.

Description

Technical Field

[0001] This application relates to the field of power system technology, and in particular to a control circuit for secondary circuit interlocking of a motor integrated protection device. Background Technology

[0002] Relay protection devices refer to automated measures and equipment that can promptly issue warning signals to operating personnel or directly issue trip commands to the controlled circuit breakers to terminate the development of these events when a fault occurs in a power component (such as a generator or line) or the power system itself, endangering the safe operation of the power system.

[0003] Currently, relay protection devices typically implement interlocking functions through software programs or with the aid of a DCS control system. However, this method of implementing interlocking functions is costly due to the high cost of replacing new devices or setting up a DCS system, and involves a large amount of retrofitting work, leading to an increased failure rate in the later stages. Utility Model Content

[0004] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a control circuit for secondary circuit interlocking in a comprehensive motor protection device, which can replace software programs or rely on a DCS control system to achieve motor protection device interlocking, saving costs, requiring minimal modification work, and effectively reducing the subsequent failure rate.

[0005] This application provides a control circuit for secondary circuit interlocking of a motor integrated protection device, including: a power supply positive terminal, a power supply negative terminal, a motor protection device, a circuit breaker closing interlocking circuit, a closing circuit, a tripping circuit, and a protection circuit;

[0006] The circuit breaker closing interlocking circuit includes an interlocking electromagnet and a normally closed auxiliary contact of a third intermediate relay. The two ends of the interlocking electromagnet are respectively connected to the negative terminal of the power supply and the normally closed auxiliary contact of the third intermediate relay. The end of the normally closed auxiliary contact of the third intermediate relay away from the interlocking electromagnet is connected to the positive terminal of the power supply.

[0007] The closing circuit includes a closing coil, a DCS closing relay, a closing button, and a first contact point of a motor protection device. The two ends of the closing coil are respectively connected to the negative terminal of the power supply and the first contact point of the motor protection device. The two ends of the DCS closing relay are respectively connected to the end of the first contact point of the motor protection device away from the closing coil and the positive terminal of the power supply. One end of the closing button is connected in parallel with the DCS closing relay.

[0008] The tripping circuit includes a tripping coil, a normally open auxiliary contact for the circuit breaker closing status signal, a tripping button, a DCS tripping relay, and a second connection contact for the motor protection device. The two ends of the tripping coil are respectively connected to the negative terminal of the power supply and the normally open auxiliary contact for the circuit breaker closing status signal. The two ends of the second connection contact for the motor protection device are respectively connected to the end of the normally open auxiliary contact for the circuit breaker closing status signal away from the tripping coil and the DCS tripping relay. The two ends of the DCS tripping relay are respectively connected to the end of the normally open auxiliary contact for the circuit breaker closing status signal away from the second connection contact for the motor protection device and the positive terminal of the power supply. The tripping button is connected in parallel with the DCS tripping relay.

[0009] The protection circuit includes a coil of a third intermediate relay and a protection output node of a motor protection device. The two ends of the coil of the third intermediate relay are respectively connected to the negative terminal of the power supply and the protection output node of the motor protection device. The end of the protection output node of the motor protection device away from the coil of the third intermediate relay is connected to the positive terminal of the power supply.

[0010] According to some embodiments of this application, the motor protection device further includes a power connection contact for the motor protection device, the two ends of which are respectively connected to the positive terminal and the negative terminal of the power supply.

[0011] According to some embodiments of this application, the circuit breaker closing interlocking circuit further includes a first working state trigger switch, the two ends of which are respectively connected to the interlocking electromagnet and the normally closed auxiliary contact of the third intermediate relay.

[0012] According to some embodiments of this application, the closing circuit further includes a second working state trigger switch, the two ends of which are respectively connected to the first contact point of the motor protection device and the closing button.

[0013] According to some embodiments of this application, the closing circuit further includes a changeover switch, wherein the first contact of the changeover switch is connected in series with the DCS closing relay, the second contact of the changeover switch is connected in series with the closing button, and the first contact of the changeover switch and the second contact of the changeover switch are connected in parallel.

[0014] In this application, when the motor protection device is operating normally, the protection output node of the motor protection device is a normally open contact. At this time, the coil of the third intermediate relay is not energized, the locking electromagnet is energized and released, and the circuit breaker can be closed normally. When the motor protection device trips, the protection output node of the motor protection device closes. At this time, the coil of the third intermediate relay is energized, the normally closed auxiliary contact of the third intermediate relay opens, the locking electromagnet is de-energized and locked, and the circuit breaker cannot be closed. Only after manually resetting the motor protection device, the protection output node of the motor protection device is released, the coil of the third intermediate relay is de-energized, the normally closed auxiliary contact of the third intermediate relay is reset, the locking electromagnet is energized, and the circuit breaker can be allowed to operate and close. By inserting the normally open auxiliary contact of the circuit breaker closing status signal in series in the tripping circuit, when the circuit breaker is in the closed position, the normally open auxiliary contact of the circuit breaker closing status signal closes, and the tripping circuit can be connected. This can effectively prevent the tripping coil from burning out due to prolonged energization. This application, through this setting, can replace software programs or rely on DCS control systems to realize the interlocking of motor protection devices, saving costs, requiring less modification work, and effectively reducing the failure rate in the later stages.

[0015] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0016] Additional aspects and advantages of this application will become apparent and readily understood in conjunction with the following description of the embodiments, in which:

[0017] Figure 1 A circuit diagram of the control circuit for secondary circuit interlocking of the integrated motor protection device provided in this application embodiment. Detailed Implementation

[0018] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0019] In the description of this application, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0020] In the description of this application, the use of "first" and "second" is for the purpose of distinguishing technical features only, and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the order of the technical features indicated.

[0021] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0022] Relay protection devices refer to automated measures and equipment that can promptly issue warning signals to operating personnel or directly issue trip commands to the controlled circuit breakers to terminate the development of these events when a fault occurs in a power component (such as a generator or line) or the power system itself, endangering the safe operation of the power system.

[0023] Currently, relay protection devices typically implement interlocking functions through software programs or with the aid of a DCS control system. However, this method of implementing interlocking functions is costly due to the high cost of replacing new devices or setting up a DCS system, and involves a large amount of retrofitting work, leading to an increased failure rate in the later stages.

[0024] To address the aforementioned problems, this application proposes a control circuit for secondary circuit interlocking in a comprehensive motor protection device. The embodiments of this application will be further described below with reference to the accompanying drawings.

[0025] Reference Figure 1This application provides a control circuit for secondary circuit interlocking of a motor integrated protection device, including a positive power supply, a negative power supply, a motor protection device, a circuit breaker closing interlocking circuit, a closing circuit, a tripping circuit, and a protection circuit. The circuit breaker closing interlocking circuit includes a locking electromagnet and a normally closed auxiliary contact of a third intermediate relay. The two ends of the locking electromagnet are connected to the negative power supply and the normally closed auxiliary contact of the third intermediate relay, respectively. The end of the normally closed auxiliary contact of the third intermediate relay furthest from the locking electromagnet is connected to the positive power supply. The closing circuit includes a closing coil, a DCS closing relay, a closing button, and a first connection contact of the motor protection device. The two ends of the closing coil are connected to the negative power supply and the first connection contact of the motor protection device, respectively. The two ends of the DCS closing relay are connected to the end of the first connection contact of the motor protection device furthest from the closing coil and the positive power supply, respectively. One end of the closing button is connected in parallel with the DCS closing relay. The tripping circuit includes... The circuit includes a trip coil, a normally open auxiliary contact for the circuit breaker closing status signal, a trip button, a DCS trip relay, and a second contact of the motor protection device. The two ends of the trip coil are connected to the negative power supply and the normally open auxiliary contact for the circuit breaker closing status signal, respectively. The two ends of the second contact of the motor protection device are connected to the end of the normally open auxiliary contact for the circuit breaker closing status signal furthest from the trip coil and the DCS trip relay, respectively. The two ends of the DCS trip relay are connected to the end of the normally open auxiliary contact for the circuit breaker closing status signal furthest from the second contact of the motor protection device and the positive power supply, respectively. The trip button is connected in parallel with the DCS trip relay. The protection circuit includes the coil of a third intermediate relay and the protection output node of the motor protection device. The two ends of the coil of the third intermediate relay are connected to the negative power supply and the protection output node of the motor protection device, respectively. The end of the protection output node of the motor protection device furthest from the coil of the third intermediate relay is connected to the positive power supply.

[0026] It should be noted that, in Figure 1 In Chinese: RL represents the locking electromagnet, ZJ 31 This indicates the normally closed auxiliary contact of the third intermediate relay, ZJ. 32 The following symbols represent the coil of the third intermediate relay: MC represents the closing coil, ZJ1 represents the DCS closing relay, MO represents the tripping coil, HK represents the normally open auxiliary contact of the circuit breaker closing status signal, -KM represents the negative power supply, +KM represents the positive power supply, In represents the motor protection device, K1 represents the protection output node of the motor protection device, SB1 represents the closing button, SB2 represents the opening button, and ZJ2 represents the DCS opening relay.

[0027] It should be noted that this application achieves motor protection device interlocking by replacing software programs or DCS control systems with this setting, thus saving costs; by adding intermediate relays to replace software programs or DCS control systems to achieve motor protection device interlocking, the amount of modification work is small; only the signal node of the motor protection device protection action needs to be connected in series in the control circuit, the control circuit modification is small, the failure rate is reduced, the modification is quick and simple, and it can be applied to a wide range in a short time.

[0028] In this application, when the motor protection device is operating normally, the protection output node of the motor protection device is a normally open contact. At this time, the coil of the third intermediate relay is not energized, the locking electromagnet is energized and released, and the circuit breaker can be closed normally. When the motor protection device trips, the protection output node of the motor protection device closes. At this time, the coil of the third intermediate relay is energized, the normally closed auxiliary contact of the third intermediate relay opens, the locking electromagnet is de-energized and locked, and the circuit breaker cannot be closed. Only after manually resetting the motor protection device, the protection output node of the motor protection device is released, the coil of the third intermediate relay is de-energized, the normally closed auxiliary contact of the third intermediate relay is reset, the locking electromagnet is energized, and the circuit breaker can be allowed to operate and close. By inserting the normally open auxiliary contact of the circuit breaker closing status signal in series in the tripping circuit, when the circuit breaker is in the closed position, the normally open auxiliary contact of the circuit breaker closing status signal closes, and the tripping circuit can be connected. This can effectively prevent the tripping coil from burning out due to prolonged energization. This application, through this setting, can replace software programs or rely on DCS control systems to realize the interlocking of motor protection devices, saving costs, requiring less modification work, and effectively reducing the failure rate in the later stages.

[0029] It is understandable that the motor protection device also includes the power connection contacts of the motor protection device, and the two ends of the power connection contacts of the motor protection device are connected to the positive terminal and the negative terminal of the power supply, respectively.

[0030] It should be noted that the motor is powered by connecting the power supply contacts of the motor protection device.

[0031] Reference Figure 1 It is understandable that the circuit breaker closing interlocking circuit also includes a first working state trigger switch, the two ends of which are connected to the interlocking electromagnet and the normally closed auxiliary contact of the third intermediate relay, respectively.

[0032] It should be noted that, in Figure 1 In the diagram, S1 represents the first working state trigger switch.

[0033] It should be noted that the circuit breaker operating trolley is movable. The first operating state trigger switch is set as the first operating position of the trolley. When the circuit breaker trolley moves to the first operating position, the first operating state trigger switch is closed, the closing interlocking circuit is connected, and the circuit breaker can normally perform closing interlocking. When the circuit breaker trolley does not reach the first operating position, the first operating state trigger switch is opened, the closing interlocking circuit is disconnected, and the circuit breaker cannot perform closing interlocking.

[0034] Reference Figure 1 It is understandable that the closing circuit also includes a second working state trigger switch, the two ends of which are connected to the first contact point of the motor protection device and the closing button, respectively.

[0035] It should be noted that, in Figure 1 In this circuit breaker, S2 represents the first working state trigger switch. The second working state trigger switch is set to the second working position of the circuit breaker trolley. When the circuit breaker trolley moves to the second working position, the second working state trigger switch is closed, the closing circuit is connected, and the circuit breaker can close normally. When the circuit breaker trolley has not reached the second working position, the second working state trigger switch is open, the closing circuit is disconnected, and the circuit breaker cannot perform the closing operation.

[0036] Reference Figure 1 It is understandable that the closing circuit also includes a changeover switch. The first contact of the changeover switch is connected in series with the DCS closing relay, the second contact of the changeover switch is connected in series with the closing button, and the first contact of the changeover switch and the second contact of the changeover switch are connected in parallel.

[0037] It should be noted that, in Figure 1 In the diagram, ZK represents a changeover switch. The first contact of the changeover switch is the remote start contact, and the second contact of the changeover switch is the local start contact.

[0038] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0039] The above description is the preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications are also considered to be within the scope of protection of this application.

[0040] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A control circuit for secondary circuit interlocking in a comprehensive protection device for electric motors, characterized in that, include: Power supply positive terminal, power supply negative terminal, motor protection device, circuit breaker closing interlocking circuit, closing circuit, tripping circuit and protection circuit; The circuit breaker closing interlocking circuit includes an interlocking electromagnet and a normally closed auxiliary contact of a third intermediate relay. The two ends of the interlocking electromagnet are respectively connected to the negative terminal of the power supply and the normally closed auxiliary contact of the third intermediate relay. The end of the normally closed auxiliary contact of the third intermediate relay away from the interlocking electromagnet is connected to the positive terminal of the power supply. The closing circuit includes a closing coil, a DCS closing relay, a closing button, and a first contact point of a motor protection device. The two ends of the closing coil are respectively connected to the negative terminal of the power supply and the first contact point of the motor protection device. The two ends of the DCS closing relay are respectively connected to the end of the first contact point of the motor protection device away from the closing coil and the positive terminal of the power supply. One end of the closing button is connected in parallel with the DCS closing relay. The tripping circuit includes a tripping coil, a normally open auxiliary contact for the circuit breaker closing status signal, a tripping button, a DCS tripping relay, and a second connection contact for the motor protection device. The two ends of the tripping coil are respectively connected to the negative terminal of the power supply and the normally open auxiliary contact for the circuit breaker closing status signal. The two ends of the second connection contact for the motor protection device are respectively connected to the end of the normally open auxiliary contact for the circuit breaker closing status signal away from the tripping coil and the DCS tripping relay. The two ends of the DCS tripping relay are respectively connected to the end of the normally open auxiliary contact for the circuit breaker closing status signal away from the second connection contact for the motor protection device and the positive terminal of the power supply. The tripping button is connected in parallel with the DCS tripping relay. The protection circuit includes a coil of a third intermediate relay and a protection output node of a motor protection device. The two ends of the coil of the third intermediate relay are respectively connected to the negative terminal of the power supply and the protection output node of the motor protection device. The end of the protection output node of the motor protection device away from the coil of the third intermediate relay is connected to the positive terminal of the power supply.

2. The control circuit for secondary circuit interlocking of the integrated motor protection device according to claim 1, characterized in that, The motor protection device also includes a power contact for connecting the motor protection device, and the two ends of the power contact for connecting the motor protection device are respectively connected to the positive terminal and the negative terminal of the power supply.

3. The control circuit for secondary circuit interlocking of the integrated motor protection device according to claim 1, characterized in that, The circuit breaker closing interlocking circuit also includes a first working state trigger switch, the two ends of which are respectively connected to the interlocking electromagnet and the normally closed auxiliary contact of the third intermediate relay.

4. The control circuit for secondary circuit interlocking of the integrated motor protection device according to claim 1, characterized in that, The closing circuit also includes a second working state trigger switch, the two ends of which are respectively connected to the first connection contact of the motor protection device and the closing button.

5. The control circuit for secondary circuit interlocking of the integrated motor protection device according to claim 1, characterized in that, The closing circuit also includes a changeover switch, the first contact of which is connected in series with the DCS closing relay, the second contact of which is connected in series with the closing button, and the first contact of which is connected in parallel with the second contact of which is connected in parallel.

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