System capable of improving power supply reliability of cooling fan of excitation power cabinet

Abstract

The utility model discloses a system capable of improving power supply reliability of a cooling fan of an excitation power cabinet, and relates to the technical field of excitation power cabinets. The circuit comprises a KM3 contactor, a KM4 contactor, a KM1 normally open contact, a KM2 normally open contact, a Q2 air switch and a Q3 air switch, an A1 coil point of the KM3 contactor is connected to a KM1 normally open upper port, a lower port of the normally open contact is connected to an A1 position of the KM3 contactor, an A1 coil point of the KM4 contactor is connected to a KM2 normally open upper port, and a lower port of the normally open contact is connected to an A1 position of the KM4 contactor. According to the utility model, the air switches Q2 and Q3 are closed, the current passes through the normally open contact KM1 to enable the main loop fan to be electrified to operate, and the contactor KM3 is closed, so that the normal operation of the main fan is realized, effective heat dissipation is provided for the excitation power cabinet, the normal operation of equipment is ensured, and the circuit connection mode enables the operation of the main loop fan to be more stable and reliable.

Description

Technical Field

[0001] This utility model relates to the field of excitation power cabinet technology, specifically to a system that can improve the power supply reliability of the cooling fan of the excitation power cabinet. Background Technology

[0002] The excitation power cabinet monitors and controls the excitation system to ensure the normal operation of the generator excitation. It can monitor parameters such as excitation current, voltage, and frequency, and adjust and control the operating status of the excitation system as needed. Simultaneously, the excitation power cabinet can coordinate the excitation power among generators, enabling them to balance power load during grid-connected operation and improving the overall efficiency and stability of the power generation system.

[0003] When the fan inside the power cabinet malfunctions, the internal thyristor section generates a lot of heat. If the heat cannot be dissipated in time, it will reduce the output efficiency of the power cabinet and may even affect the unit load. Therefore, this application provides a system that can improve the power supply reliability of the excitation power cabinet cooling fan. Utility Model Content

[0004] To achieve the above objectives, this utility model specifically adopts the following technical solution:

[0005] A system for improving the power supply reliability of the cooling fan in an excitation power cabinet includes a KM3 contactor, a KM4 contactor, a normally open contact of KM1, a normally open contact of KM2, an air switch of Q2, and an air switch of Q3. The A1 coil of the KM3 contactor is connected to the upper normally open port of the KM1 contactor, and the lower normally open port is connected to the A1 terminal of the KM3 contactor. The A1 coil of the KM4 contactor is connected to the upper normally open port of the KM2 contactor, and the lower normally open port is connected to the A1 terminal of the KM4 contactor. Under normal operating conditions, when the Q2 and Q3 air switches are closed, current flows through the normally open contact of KM1 to energize the main circuit fan. At this time, the KM3 contactor is energized, and the circuit is in the main fan operating state, providing effective heat dissipation for the excitation power cabinet and ensuring the normal operation of the equipment.

[0006] Furthermore, it also includes a cable and four LADN11 one-on-one-off auxiliary contacts to ensure current transmission. The LADN11 one-on-one-off auxiliary contacts can realize corresponding auxiliary control functions according to the needs of the circuit.

[0007] Furthermore, when a phase-to-phase short circuit fault occurs in the main circuit fan, the Q2 air switch opens, and the KM3 contactor releases accordingly, cutting off the power supply to the main circuit fan and preventing the short circuit current from impacting the T isolation transformer and the excitation transformer, thus protecting the safety of these devices.

[0008] Furthermore, when a ground short circuit fault occurs in the main circuit fan, the Q2 air switch is disconnected, and the KM3 contactor is released accordingly, ensuring circuit safety. The main circuit fan is disconnected from the power supply, ensuring circuit safety and preventing the ground fault from causing greater damage to the entire system.

[0009] Furthermore, when an inter-turn short circuit occurs inside the fan, the Q2 air switch disconnects, stopping the main circuit fan and preventing the fault from escalating further.

[0010] Furthermore, in abnormal operating conditions, when the Q2 air switch is disconnected and the Q3 air switch remains closed, current flows through the normally open contact of KM2 to activate the KM4 contactor, and the standby fan is put into operation.

[0011] Furthermore, after the main fan is repaired, first close the Q2 air switch, then open the Q3 air switch, and then close the Q3 air switch again. The current flows through the normally open contact of KM1 to make the KM3 contactor engage, and the main fan resumes operation.

[0012] Furthermore, during the entire fan operation and switching process, there is no need to short-circuit the control circuit to achieve the fan switching operation, thus avoiding more failures caused by short-circuit errors.

[0013] The beneficial effects of this utility model are as follows:

[0014] 1. This utility model achieves normal operation of the main circuit fan by closing air switches Q2 and Q3, allowing current to flow through the normally open contact of KM1 to power the fan and activate the contactor KM3, thus providing effective heat dissipation for the excitation power cabinet and ensuring the normal operation of the equipment. This circuit connection method makes the operation of the main circuit fan more stable and reliable, reduces the risk of equipment temperature rise and potential damage caused by fan failure, and improves the stability of the entire system.

[0015] 2. When air switches Q2 and Q3 are closed, the circuit can automatically start the main circuit fan without manual intervention, which improves the automation level of the system and reduces the possibility of human error.

[0016] 3. The normal operation of the main circuit fan of this utility model helps to dissipate the heat generated in the excitation power cabinet in a timely manner, avoiding damage to the equipment due to overheating and ensuring the safe operation of the equipment. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural diagram of the present invention; Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings.

[0019] This application provides a system for improving the power supply reliability of the cooling fan in an excitation power cabinet. It primarily addresses the problem of increased internal temperature due to insufficient heat dissipation. The following technical solution is provided and will be described in detail: Example

[0020] like Figure 1 As shown, in some embodiments, the circuit includes contactors KM3 and KM4, normally open contacts KM1 and KM2, air switches Q2 and Q3. The A1 coil of contactor KM3 is connected to the upper normally open port of KM1, and the lower normally open port is connected to the A1 of contactor KM3. The A1 coil of contactor KM4 is connected to the upper normally open port of KM2, and the lower normally open port is connected to the A1 of contactor KM4. Under normal operating conditions, when air switches Q2 and Q3 are closed, current flows through the normally open contact of KM1 to energize the main circuit fan. At this time, contactor KM3 is energized, and the circuit is in the main fan operating state. The circuit also includes a cable and four LADN11 auxiliary contacts that are open and closed.

[0021] Specifically: When air switches Q2 and Q3 are closed, current flows through the normally open contact of KM1 to energize the main circuit fan and enable it to run. Contactor KM3 is then engaged, enabling the main fan to operate normally and providing effective heat dissipation for the excitation power cabinet. This ensures the normal operation of the equipment. This circuit connection method makes the operation of the main circuit fan more stable and reliable, reduces the risk of equipment temperature rise and potential damage caused by fan failure, and thus improves the stability of the entire system.

[0022] The working principle here is as follows: Under normal operating conditions, when air switches Q2 and Q3 are closed, a current path is formed. Current flows from the power source, through air switches Q2 and Q3, and reaches the normally open contact of KM1. At this time, the normally open contact of KM1 is in the closed state, allowing current to flow through and to the A1 coil of contactor KM3. After the current enters the A1 coil of contactor KM3, it causes contactor KM3 to engage, thereby connecting the power supply to the main circuit fan. The main circuit fan is powered on and runs, and the circuit is in the main fan operating state. Simultaneously, the device also includes a cable and four LADN11 one-on-one-closed auxiliary contacts. The cable is used to connect various... Each electrical component ensures current transmission. The LADN11 one-on-one auxiliary contact can realize corresponding auxiliary control functions according to the needs of the circuit. For example, in some cases, these auxiliary contacts can be used to realize interlock control of the contactor, or to indicate the working status of the circuit. When the main circuit fan fails or needs to be switched to the standby fan, the circuit state can be switched by controlling the opening of the Q2 air switch and the action of other electrical components, so that the standby fan can be put into operation to ensure the heat dissipation requirements of the excitation power cabinet. The specific switching process will be adjusted according to the actual fault situation and circuit design.

[0023] like Figure 1As shown, in some embodiments, when a phase-to-phase short circuit fault occurs in the main circuit fan, the Q2 air switch opens, and the KM3 contactor releases accordingly, cutting off the power supply to the main circuit fan and preventing the short circuit current from impacting the T isolation transformer and the excitation transformer. When a ground short circuit fault occurs in the main circuit fan, the Q2 air switch opens, and the KM3 contactor releases accordingly, ensuring circuit safety. When an inter-turn short circuit occurs inside the fan, the Q2 air switch opens, stopping the main circuit fan from running. The working principle here is as follows: When a phase-to-phase short circuit occurs in the main circuit fan, the short circuit current will increase instantaneously. At this time, the Q2 air switch will detect the excessive current, and its internal protection device will activate, causing the Q2 air switch to open. Since the A1 coil of the KM3 contactor is connected to the power supply through the normally open contact of KM1 and the Q2 air switch, when the Q2 air switch opens, the A1 coil of the KM3 contactor is de-energized, the electromagnetic attraction of the contactor core disappears, and the contacts of the KM3 contactor are in the spring action. The reset switch releases the contactor, cutting off the power to the main circuit fan. This prevents the short-circuit current from continuing to flow through the main circuit fan, protecting the T-isolation transformer and excitation transformer from impact. When a ground fault occurs in the main circuit fan, it will also cause an abnormal increase in current. The Q2 air switch will respond quickly, disconnecting the circuit. The A1 coil of the KM3 contactor will be de-energized due to the disconnection of the Q2 air switch, causing the KM3 contactor to release and disconnect the main circuit fan from the power supply, ensuring circuit safety and preventing the ground fault from causing greater damage to the entire system. When an inter-turn short circuit occurs inside the fan, although it may not generate a short-circuit current as large as a phase-to-phase or ground fault, it will still cause abnormal fan operation. The Q2 air switch will detect this abnormality and disconnect, de-energizing the A1 coil of the KM3 contactor. The KM3 contactor will release, stopping the operation of the main circuit fan and preventing the fault from escalating further. Example

[0024] The solution in Example 1 will be further described below with reference to its specific working method.

[0025] like Figure 1As shown, in some embodiments, under abnormal operating conditions, when air switch Q2 is disconnected and air switch Q3 remains closed, current flows through the normally open contact of KM2 to activate contactor KM4, and the standby fan starts operating. After the main fan is repaired, air switch Q2 is closed first, then air switch Q3 is disconnected, and then air switch Q3 is closed again. Current flows through the normally open contact of KM1 to activate contactor KM3, and the main fan resumes operation. Throughout the entire fan operation and switching process, there is no need to short-circuit the control circuit to achieve the fan switching operation, avoiding more faults caused by short-circuit errors. The working principle here is as follows: When the system is in an abnormal operating condition and needs to switch to the standby fan, air switch Q2 is disconnected. At this time, the power supply to the main circuit fan is cut off. Since air switch Q3 remains closed, current flows through the normally open contact of KM2. Under normal circumstances, the normally open contact of KM2 is open, but when it is necessary to switch to the standby fan, other control signals will close the normally open contact of KM2, allowing current to flow through the normally open contact of KM2. When the main fan is repaired, the current reaches the A1 coil of the KM4 contactor. This current enters the A1 coil of the KM4 contactor, causing it to engage and power on the standby fan, which then begins operation. When the main fan is repaired and needs to be restored, the Q2 air switch is closed first, allowing current to flow through it. Then, the Q3 air switch is opened to disconnect the standby fan. Next, the Q3 air switch is closed again. Since the normally open contact of the KM1 is closed when the main fan is operating normally, the current flows through the KM1 normally open contact to the A1 coil of the KM3 contactor. This current then engages the KM3 contactor, powering on the main fan and restoring its operation. Throughout the fan operation and switching process, the above circuit design and the coordination of the contactors and air switches enable automatic fan switching without the need for short-circuiting the control circuit. This avoids further malfunctions caused by incorrect short-circuiting and improves the system's reliability and safety.

[0026] Operating Step 1: Under normal operating conditions, air switches Q2 and Q3 are closed, and current flows through the normally open contact of KM1 to energize the main circuit fan. Contactor KM3 is energized, and the circuit is in main fan operation mode, providing heat dissipation for the main excitation power cabinet. When a phase-to-phase short circuit fault occurs in the main circuit fan, the excessive short-circuit current will cause air switch Q2 to open, de-energizing coil A1 of contactor KM3 and releasing the contactor, thereby cutting off the main circuit fan power supply and preventing the short-circuit current from impacting the T-isolation transformer and excitation transformer. When a ground short circuit fault occurs in the main circuit fan, air switch Q2 will also open, and contactor KM3 will release accordingly, ensuring circuit safety. When an inter-turn short circuit occurs inside the fan, air switch Q2 will open, stopping the main circuit fan operation.

[0027] Step 2: In case of abnormal operation, when switching to the standby fan is required, disconnect the Q2 air switch while keeping the Q3 air switch closed. At this time, the current flows through the normally open contact of KM2, causing the KM4 contactor to engage, and the standby fan starts running. After the main fan is repaired, first close the Q2 air switch, then disconnect the Q3 air switch, and then close the Q3 air switch again. The current flows through the normally open contact of KM1, causing the KM3 contactor to engage, and the main fan resumes operation. Throughout the entire fan operation and switching process, through reasonable circuit design and the coordination of contactors and air switches, automatic fan switching is achieved without the need for short-circuiting the control circuit. This avoids more faults caused by short-circuiting errors, improves the reliability and safety of the system, ensures the heat dissipation requirements of the excitation power cabinet, and maintains the normal operation of the equipment.

[0028] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A system for improving the power supply reliability of the cooling fan in an excitation power cabinet, comprising contactor KM3, contactor KM4, normally open contact KM1, normally open contact KM2, air switch Q2, and air switch Q3, characterized in that, The A1 coil of the KM3 contactor is connected to the normally open upper port of KM1, and the lower port of the normally open contact is connected to the A1 of the KM3 contactor. The A1 coil of the KM4 contactor is connected to the normally open upper port of KM2, and the lower port of the normally open contact is connected to the A1 of the KM4 contactor. Under normal operating conditions, when the Q2 and Q3 air switches are closed, the current flows through the normally open contact of KM1 to energize the main circuit fan and make it run. At this time, the KM3 contactor is energized, and the circuit is in the main fan operating state.

2. The system for improving the power supply reliability of the cooling fan in the excitation power cabinet according to claim 1, characterized in that, It also includes cables and four LADN11 one-on-one auxiliary contacts.

3. The system for improving the power supply reliability of the cooling fan in the excitation power cabinet according to claim 1, characterized in that, When a phase-to-phase short circuit fault occurs in the main circuit fan, the Q2 air switch opens, and the KM3 contactor releases accordingly, cutting off the power supply to the main circuit fan and preventing the short circuit current from impacting the T isolation transformer and the excitation transformer.

4. The system for improving the power supply reliability of the cooling fan in the excitation power cabinet according to claim 1, characterized in that, When a ground short circuit fault occurs in the main circuit fan, the Q2 air switch will open, and the KM3 contactor will release accordingly, ensuring circuit safety.

5. A system for improving the power supply reliability of the cooling fan in an excitation power cabinet according to claim 1, characterized in that, When an inter-turn short circuit occurs inside the fan, the Q2 air switch opens, stopping the main circuit fan from running.

6. A system for improving the power supply reliability of the cooling fan in an excitation power cabinet according to claim 1, characterized in that, In case of abnormal operation, when the Q2 air switch is disconnected and the Q3 air switch remains closed, the current flows through the normally open contact of KM2 to activate the KM4 contactor, and the standby fan is put into operation.

7. A system for improving the power supply reliability of the cooling fan in an excitation power cabinet according to claim 1, characterized in that, After the main fan is repaired, first close the Q2 air switch, then open the Q3 air switch, and then close the Q3 air switch again. The current flows through the normally open contact of KM1 to make the KM3 contactor engage, and the main fan resumes operation.

8. A system for improving the power supply reliability of the cooling fan in an excitation power cabinet according to claim 1, characterized in that, Throughout the entire fan operation and switching process, there is no need to short-circuit the control circuit to achieve the fan switching operation.

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