Multi-fan soft start control cabinet for mutual standby

Abstract

The utility model relates to a soft start control cabinet, in particular to a multi-fan soft start control cabinet for mutual standby, which comprises a control switch assembly, a fan main loop and a control loop, the control switch assembly comprises a main circuit breaker and a plurality of branch circuit breakers, the output end of the main circuit breaker is connected with each branch circuit breaker through a parallel branch; the fan main loop is provided with at least one mutual standby interconnection contactor and more than two fan control loops, the loop is connected with the main circuit breaker through the shunt circuit breaker, soft start paths of any two loops are bridged and interconnected through the mutual standby interconnection contactor, and each loop is connected with one fan; the PLC controller of the control loop is connected with the mutual standby interconnection contactor, the main circuit breaker and the branch circuit breaker. According to the control cabinet, the reliability and continuity of a multi-fan system are remarkably improved, the hardware redundancy cost is reduced, the control cabinet is suitable for industrial ventilation, environmental protection equipment, energy power and other scenes with high requirements for starting stability, production safety can be guaranteed, and intelligent control is achieved.

Description

Technical Field

[0001] This utility model relates to a soft start control cabinet, and more particularly to a multi-fan soft start control cabinet that serves as a backup for each other. Background Technology

[0002] In high-power wind turbine control systems, the soft starter, as a core control unit, is primarily used to achieve smooth wind turbine startup. For example... Figure 1 The soft starter uses a three-phase parallel thyristor voltage regulation circuit connected in series between the three-phase AC power supply (U / V / W) and the stator winding of the fan. It adjusts the motor input voltage by precisely controlling the thyristor conduction angle. Its working principle is as follows: During operation, the control board sends a synchronous trigger signal via a pulse trigger module according to preset start-up curve parameters, dynamically adjusting the conduction angle. During startup, the conduction angle gradually increases from zero, and the motor terminal voltage rises smoothly according to a preset function, resulting in a steady increase in torque and speed, achieving a smooth start. After reaching the rated speed, the thyristors are fully conducting, and the motor operates at the rated voltage. During shutdown, the control board reverses the conduction angle, reducing the motor terminal voltage to achieve a soft stop.

[0003] Currently, independent multi-fan soft starter cabinets generally adopt a one-to-one independent control architecture. Under this architecture, each soft starter is connected to a single fan to form a dedicated drive circuit, thereby enabling independent and precise control of operating parameters such as start-up, shutdown, and speed of each fan to adapt to diverse operating conditions.

[0004] However, the aforementioned one-to-one independent control architecture has significant technical drawbacks. If the soft starter corresponding to a particular wind turbine fails, due to the specific nature of the drive circuit, the turbine will lose its starting capability, leading to an interruption of the entire production process and severely impacting production efficiency and continuity. While adding redundant soft starters to create a one-for-one backup mechanism can solve the downtime problem caused by failures, it significantly increases hardware procurement costs, equipment installation space requirements, and system maintenance complexity, making it difficult to achieve an effective balance between reliability improvement and cost control. Utility Model Content

[0005] Therefore, the technical problem to be solved by this utility model is to overcome the problem that a failure of the soft starter in the existing one-to-one independent control architecture will cause the corresponding fan to fail to start and the production process to be interrupted. Although adding a redundant soft starter to build a backup mechanism can solve the downtime problem, it has the problems of high hardware procurement costs, large equipment installation space requirements and complex system operation and maintenance.

[0006] To address the aforementioned technical problems, this utility model provides a multi-fan soft-start control cabinet with mutual backup, enabling the soft starters in two soft-start cabinets of the same power to serve as backups for each other. In the event of a failure in one soft starter, the other can be used for emergency starting, thereby ensuring production stability and safety. Specifically, the multi-fan soft-start control cabinet includes: a control switch assembly, a fan main circuit, and a control circuit; wherein,

[0007] The control switch assembly includes a main circuit breaker connected to a three-phase power supply and multiple branch circuit breakers. The output of the main circuit breaker is connected to each branch circuit breaker through multiple parallel branches.

[0008] The main circuit of the wind turbine includes at least one backup contactor and at least two wind turbine control circuits. The wind turbine control circuits are connected one-to-one with each branch of the main circuit breaker through corresponding branch circuit breakers. The soft start path in any two wind turbine control circuits is bridging and interconnected through the backup contactor. Each wind turbine control circuit is connected to one wind turbine.

[0009] The control loop includes a PLC controller, which is connected to the interconnecting contactor, the main circuit breaker, and the multiple branch circuit breakers.

[0010] In one embodiment of this utility model, the wind turbine control circuit is configured as a first wind turbine control circuit and a second wind turbine control circuit. The first soft-start path in the first wind turbine control circuit is connected to the first wind turbine, and the second soft-start path in the second wind turbine control circuit is connected to the second wind turbine. The mutual backup contactor is connected across both the first soft-start path and the second soft-start path.

[0011] In one embodiment of the present invention, the first fan control circuit includes a first bypass operating path, on which a first contactor and a first thermal relay are provided. The main incoming terminal of the first contactor is connected to a corresponding branch circuit breaker, the main outgoing terminal of the first contactor is connected to the main incoming terminal of the first thermal relay, and the main outgoing terminal of the first thermal relay is connected to the first fan.

[0012] The first soft start path is provided with a first soft starter and a third contactor. The main incoming terminal of the first soft starter is connected to the corresponding branch circuit breaker, the main outgoing terminal of the first soft starter is connected to the main incoming terminal of the third contactor, and the main outgoing terminal of the third contactor is connected to the first fan.

[0013] In one embodiment of this utility model, the second fan control circuit includes a second bypass operating path, on which a second contactor and a second thermal relay are provided. The main incoming terminal of the second contactor is connected to a corresponding branch circuit breaker, the main outgoing terminal of the second contactor is connected to the main incoming terminal of the second thermal relay, and the main outgoing terminal of the second thermal relay is connected to the second fan.

[0014] The second soft starter path is provided with a second soft starter and a fifth contactor. The main incoming terminal of the second soft starter is connected to the corresponding branch circuit breaker, the main outgoing terminal of the second soft starter is connected to the main incoming terminal of the fifth contactor, and the main outgoing terminal of the fifth contactor is connected to the second fan.

[0015] In one embodiment of this utility model, the mutual backup contactor includes a fourth contactor, a sixth contactor, and a seventh contactor. The fourth contactor is connected between the third contactor and the first fan, the sixth contactor is connected between the fifth contactor and the second fan, and the main input terminal of the fourth contactor and the main input terminal of the sixth contactor are connected through the seventh contactor.

[0016] In one embodiment of this utility model, the fourth contactor, the sixth contactor, and the seventh contactor are all connected to the PLC controller.

[0017] In one embodiment of this utility model, the first contactor, the second contactor, the third contactor, and the fifth contactor are all connected to the PLC controller.

[0018] In one embodiment of this utility model, the first thermal relay and the second thermal relay are connected to the PLC controller.

[0019] In one embodiment of this utility model, the multi-fan soft-start control cabinet further includes a switching power supply, and the output terminal of the main circuit breaker is connected to the switching power supply.

[0020] In one embodiment of this utility model, the multi-fan soft-start control cabinet further includes a fuse, and the output terminal of the main circuit breaker is connected to the switching power supply through the fuse.

[0021] The above-mentioned technical solution of this utility model has the following advantages compared with the prior art:

[0022] This invention connects the soft-start paths of different wind turbines through a mutual backup contactor in the main circuit of the wind turbine, and combines the intelligent control of the PLC controller in the control circuit to realize that two soft starters can serve as backups for each other. It has significant advantages such as high reliability redundancy design to ensure continuous system operation, intelligent control logic to improve automation level, optimized hardware architecture to reduce cost and maintenance, strong scalability to adapt to multiple scenario requirements, and safety and energy efficiency advantages. It can also be expanded to a multi-wind turbine system architecture, and realize intelligent start-up and fault redundancy switching of more wind turbines by building a distributed soft-start cluster control network. Attached Figure Description

[0023] To make the content of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0024] Figure 1 This is a schematic diagram illustrating the working principle of a soft starter;

[0025] Figure 2 This is a schematic diagram of a multi-fan soft-start control cabinet provided in an embodiment of this utility model;

[0026] Figure 3 This is a schematic diagram showing the connection between the PLC controller and each contactor and thermal relay provided in the embodiments of this utility model;

[0027] Figure 4 This is a schematic diagram showing the connection of the function buttons of the PLC controller and control panel provided in an embodiment of this utility model;

[0028] Figure 5 This is a connection diagram of the PLC controller and indicator lights provided in an embodiment of this utility model;

[0029] Figure 6 This is a schematic diagram of the indicator lights on the control panel provided in an embodiment of this utility model;

[0030] Explanation of reference numerals on the accompanying drawings:

[0031] KM1, First Contactor; KM2, Second Contactor; KM3, Third Contactor; KM4, Fourth Contactor; KM5, Fifth Contactor; KM6, Sixth Contactor; KM7, Interconnecting Contactor; Q1, Main Circuit Breaker; Q2, Second Branch Circuit Breaker; Q3, Third Branch Circuit Breaker; Q4, Fourth Branch Circuit Breaker; Q5, Fifth Branch Circuit Breaker;

[0032] FR1, First thermal relay; FR2, Second thermal relay; M1, First fan; M2, Second fan; F1, Fuse; U1, Switching power supply; KA1, First relay; KA2, Second relay;

[0033] SB1, First fan start button; SB2, First fan stop button; SB3, Second fan start button; SB4, Second fan stop button; H1, First fan operation indicator light; H2, First fan fault indicator light; H3, Second fan operation indicator light; H4, Second fan fault indicator light;

[0034] 100. First soft starter; 200. Second soft starter; 300. PLC controller; 400. Control panel. Detailed Implementation

[0035] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments are not intended to limit the present invention.

[0036] Reference Figures 2-6 This utility model provides a multi-fan soft-start control cabinet that can be used as a backup for each other. The multi-fan soft-start control cabinet includes: a control switch assembly, a fan main circuit, and a control circuit.

[0037] The control switch assembly includes a main circuit breaker Q1, a second branch circuit breaker Q2, a third branch circuit breaker Q3, a fourth branch circuit breaker Q4, and a fifth branch circuit breaker Q5 connected to a three-phase power supply. The output terminal of the main circuit breaker Q1 is connected to each branch circuit breaker Q2~Q5 through multiple parallel branches.

[0038] The main circuit of the wind turbine includes at least one backup contactor and at least two wind turbine control circuits. The wind turbine control circuits are connected to the main circuit breaker Q1 through corresponding branch circuit breakers. The soft start paths in any two wind turbine control circuits are interconnected by the backup contactor. Each wind turbine control circuit is connected to one wind turbine.

[0039] The control loop includes a PLC controller 300, which controls the interconnecting contactor, the main circuit breaker Q1, and the multiple branch circuit breakers Q2 to Q5.

[0040] Specifically, in this embodiment, the wind turbine control loop is configured as a first wind turbine control loop and a second wind turbine control loop. The first soft start path in the first wind turbine control loop is connected to the first wind turbine M1, and the second soft start path in the second wind turbine control loop is connected to the second wind turbine M2. The mutual backup contactor is connected across both the first soft start path and the second soft start path.

[0041] Furthermore, the first wind turbine control circuit includes a first bypass operating path, on which a first contactor KM1 and a first thermal relay FR1 are provided. A second branch circuit breaker Q2 is connected to the main incoming terminal of the first contactor KM1, the main outgoing terminal of the first contactor KM1 is connected to the main incoming terminal of the first thermal relay FR1, and the main outgoing terminal of the first thermal relay FR1 is connected to the first wind turbine M1.

[0042] The first soft starter path is provided with a first soft starter 100 and a third contactor KM3. The third branch circuit breaker Q3 is connected to the main incoming terminal of the first soft starter 100, the main outgoing terminal of the first soft starter 100 is connected to the main incoming terminal of the third contactor KM3, and the main outgoing terminal of the third contactor KM3 is connected to the first fan M1.

[0043] Specifically, in this embodiment, the second fan control circuit includes a second bypass operating path, on which a second contactor KM2 and a second thermal relay FR2 are provided. A fifth branch circuit breaker Q5 is connected to the main incoming terminal of the second contactor KM2, the main outgoing terminal of the second contactor KM2 is connected to the main incoming terminal of the second thermal relay FR2, and the main outgoing terminal of the second thermal relay FR2 is connected to the second fan M2.

[0044] The second soft starter path is equipped with a second soft starter 200, a fifth contactor KM5, and a sixth contactor KM6. The fourth branch circuit breaker Q4 is connected to the main incoming terminal of the second soft starter 200. The main outgoing terminal of the second soft starter 200 is connected to the main incoming terminal of the fifth contactor KM5. The main outgoing terminal of the fifth contactor KM5 is connected to the main incoming terminal of the sixth contactor KM6. The main outgoing terminal of the sixth contactor KM6 is connected to the second fan M2.

[0045] Furthermore, the mutual backup contactor includes a fourth contactor KM4, a sixth contactor KM6, and a seventh contactor KM7. The fourth contactor KM4 is connected between the third contactor KM3 and the first fan M1, the sixth contactor KM6 is connected between the fifth contactor KM5 and the second fan M2, and the main input terminal of the fourth contactor and the main input terminal of the sixth contactor KM6 are connected through the seventh contactor KM7.

[0046] Furthermore, the multi-fan soft-start control cabinet also includes a switching power supply U1, a fuse F1, a first relay KA1 and a second relay KA2, and the main circuit breaker Q1 is connected to the switching power supply U1 through the fuse F1.

[0047] Furthermore, the first contactor KM1, the second contactor KM2, the third contactor KM3, the fourth contactor KM4, the fifth contactor KM5, the sixth contactor KM6, the seventh contactor KM7, the first thermal relay FR1, and the second thermal relay FR2 are all connected to the PLC controller 300.

[0048] Specifically, such as Figure 3 As shown, one end of the normally open auxiliary contact of the first thermal relay FR1 is connected to the positive pin 24+ of the switching power supply U1, and the other end is connected to the input point I0.0 of the PLC controller 300. One end of the normally open auxiliary contact of the second thermal relay FR2 is connected to the positive pin 24+ of the switching power supply U1, and the other end is connected to the input point I0.1 of the PLC controller 300.

[0049] One end of the auxiliary contact of the first contactor KM1 is connected to the positive pin 24+ of the switching power supply U1, and the other end is connected to input point I0.2 of the PLC controller 300. One end of the auxiliary contact of the second contactor KM2 is connected to the positive pin 24+ of the switching power supply U1, and the other end is connected to input point I0.3 of the PLC controller 300. One end of the auxiliary contact of the third contactor KM3 is connected to the positive pin 24+ of the switching power supply U1, and the other end is connected to input point I0.4 of the PLC controller 300. One end of the auxiliary contact of the fourth contactor KM4 is connected to the positive pin 24+ of the switching power supply U1, and the other end is connected to input point I0.5 of the PLC controller 300. One end of the auxiliary contact of the fifth contactor KM5 is connected to the positive pin 24+ of the switching power supply U1, and the other end is connected to input point I0.6 of the PLC controller 300. One end of the auxiliary contact of the sixth contactor KM6 is connected to the positive pin 24+ of the switching power supply U1, and the other end is connected to the input point I0.7 of the PLC controller 300. One end of the auxiliary contact of the seventh contactor KM7 is connected to the positive pin 24+ of the switching power supply U1, and the other end is connected to the input point I1.0 of the PLC controller 300.

[0050] One end of the bypass auxiliary contact of the first soft starter 100 is connected to the positive pin 24+ of the switching power supply U1, and the other end is connected to input point I1.1 of the PLC controller 300. One end of the fault auxiliary contact of the first soft starter 100 is connected to the positive pin 24+ of the switching power supply U1, and the other end is connected to input point I1.2 of the PLC controller 300. One end of the bypass auxiliary contact of the second soft starter 200 is connected to the positive pin 24+ of the switching power supply U1, and the other end is connected to input point I1.3 of the PLC controller 300. One end of the fault auxiliary contact of the first soft starter 100 is connected to the positive pin 24+ of the switching power supply U1, and the other end is connected to input point I1.4 of the PLC controller 300.

[0051] Specifically, the output point Q0.0 of the PLC controller 300 is connected to one end of the coil of the first contactor KM1, and the other end of the coil of the first contactor KM1 is connected to the negative pin 24- of the switching power supply U1.

[0052] Output point Q0.1 of PLC controller 300 is connected to one end of the coil of the second contactor KM2, and the other end of the coil of the second contactor KM2 is connected to the negative pin 24- of the switching power supply U1. Output point Q0.3 of PLC controller 300 is connected to one end of the coil of the third contactor KM3, and the other end of the coil of the third contactor KM3 is connected to the negative pin 24- of the switching power supply U1. Output point Q0.4 of PLC controller 300 is connected to one end of the coil of the fourth contactor KM4, and the other end of the coil of the fourth contactor KM4 is connected to the negative pin 24- of the switching power supply U1. Output point Q0.5 of PLC controller 300 is connected to one end of the coil of the fifth contactor KM5, and the other end of the coil of the fifth contactor KM5 is connected to the negative pin 24- of the switching power supply U1. Output point Q0.6 of PLC controller 300 is connected to one end of the coil of the sixth contactor KM6, and the other end of the coil of the sixth contactor KM6 is connected to the negative pin 24- of the switching power supply U1. The output point Q0.7 of the PLC controller 300 is connected to one end of the coil of contactor KM7, and the other end of the coil of contactor KM7 is connected to the negative pin 24- of the switching power supply U1.

[0053] The output point Q1.0 of the PLC controller 300 is connected to one end of the coil of the first relay KA1, and the other end of the coil of the first relay KA1 is connected to the negative pin 24- of the switching power supply U1. The output point Q1.1 of the PLC controller 300 is connected to one end of the coil of the second relay KA2, and the other end of the coil of the second relay KA2 is connected to the negative pin 24- of the switching power supply U1.

[0054] In addition, the multi-fan soft-start control cabinet provided in this embodiment is also equipped with a control panel 400, which mainly consists of buttons and indicator lights for the control circuit. Figure 4 and Figure 6 As shown, the control panel 400 is equipped with a first fan start button SB1 ( Figure 6 The button for "Start 1" and the first fan stop button SB2 ( Figure 6 The button for "Stop 1" and the second fan start button SB3 ( Figure 6 The button for "Start 2" and the second fan stop button SB4 ( Figure 6 (The button is for "Stop 2").

[0055] One end of the first fan start button SB1 is connected to the positive pin 24+ of the switching power supply, and the other end is connected to the input point I2.4 of the PLC controller 300; one end of the first fan stop button SB2 is connected to the positive pin 24+ of the switching power supply, and the other end is connected to the input point I2.5 of the PLC controller 300; one end of the second fan start button SB3 is connected to the positive pin 24+ of the switching power supply, and the other end is connected to the input point I2.6 of the PLC controller 300; one end of the second fan stop button SB4 is connected to the positive pin 24+ of the switching power supply, and the other end is connected to the input point I2.7 of the PLC controller 300.

[0056] In addition, such as Figure 5 and Figure 6 As shown, the control panel 400 is also equipped with a first fan operation indicator light H1 ( Figure 6 The indicator light for "Running 1" and the first fan fault indicator light H2 ( Figure 6 The indicator light for "Fault 1" and the second fan operation indicator light H3 ( Figure 6 The indicator light for "Running 2" and the second fan fault indicator light H4 ( Figure 6 The indicator light for "Fault 2" and the first soft starter fault indicator light H5 ( Figure 6 The indicator light for "Soft Starter 1 Fault" and the second soft starter fault indicator light H6 ( Figure 6 (This is the indicator light for "Soft Start 2 Failure").

[0057] The output point Q1.2 of the PLC controller 300 is connected to terminal X1 of the first fan operation indicator H1, and terminal X2 of the first fan operation indicator H1 is connected to the negative pin 24- of the switching power supply U1; the output point Q1.3 of the PLC controller 300 is connected to terminal X1 of the first fan fault indicator H2, and terminal X2 of indicator H2 is connected to the negative pin 24- of the switching power supply U1; the output point Q1.4 of the PLC controller 300 is connected to terminal X1 of the second fan operation indicator H3, and terminal X2 of indicator H3 is connected to the negative pin 24- of the switching power supply U1; the PLC controller... The output point Q1.5 of the PLC controller 300 is connected to the terminal X1 of the second fan fault indicator H4, and the terminal X2 of the indicator H4 is connected to the negative pin 24- of the switching power supply U1; the output point Q1.6 of the PLC controller 300 is connected to the terminal X1 of the first soft starter fault indicator H5, and the terminal X2 of the first soft starter fault indicator H5 is connected to the negative pin 24- of the switching power supply U1; the output point Q1.7 of the PLC controller 300 is connected to the terminal X1 of the second soft starter fault indicator H6, and the terminal X2 of the second soft starter fault indicator H6 is connected to the negative pin 24- of the switching power supply U1.

[0058] Preferably, the PLC controller is an S7-200SMART model, which supports IEC 61131-3 standard programming. Its powerful logic processing capabilities and rich I / O interfaces provide reliable assurance for the soft-start control of multiple fans.

[0059] Under the above hardware architecture, when neither the first soft starter 100 nor the second soft starter 200 malfunctions, the control flow is as follows:

[0060] Pressing the first fan start button SB1 illuminates the first fan's running indicator H1. The PLC controller 300 then controls the third contactor KM3 and the fourth contactor KM4 to engage. The PLC controller 300 then controls the first relay KA1 to engage, activating the first soft starter 100. The first soft starter 100 gradually increases the output voltage according to a preset ramp curve, achieving a smooth start for the first fan M1. When the first fan M1 reaches its rated speed, the first soft starter 100 outputs a bypass signal to the PLC controller 300. Upon receiving this signal, the PLC controller 300 closes the first contactor KM1, switching the first fan M1 to direct grid power supply mode. After confirming reliable engagement of the first contactor KM1, the PLC controller 300 disconnects the first relay KA1, the third contactor KM3, and the fourth contactor KM4, completing the startup process. When stopping, press the first fan stop button SB2, and the PLC controller 300 will directly disconnect the first contactor KM1, and the first fan M1 will stop by inertia.

[0061] Similar to the control and start logic of the first fan M1, pressing the second fan start button SB3 illuminates the second fan's running indicator light H3. The PLC controller 300 then controls the fifth contactor KM5 and the sixth contactor KM6 to engage. The PLC controller 300 then controls the second relay KA2 to engage, starting the second soft starter 200. Upon receiving the bypass output signal from the second soft starter 200, the PLC controller 300 controls the second contactor KM2 to engage. Upon receiving the signal that the second contactor KM2 is engaged, the PLC controller 300 disconnects the second relay KA2, simultaneously disconnecting the fifth contactor KM5 and the sixth contactor KM6 to complete the start-up. Pressing the second fan stop button SB4 extinguishes the second fan's running indicator light H3. The PLC controller 300 then controls the second contactor KM2 to disconnect, stopping the second fan M2.

[0062] When the first soft starter 100 malfunctions, its internal protection circuit activates and outputs a fault signal to the PLC controller 300. The PLC controller 300 immediately illuminates the fault indicator H5 of the first soft starter and automatically switches to redundant control mode. The control flow is as follows:

[0063] When the second soft starter 200 is idle, pressing the first fan start button SB1 causes the PLC controller 300 to illuminate both the first fan running indicator H1 and the first soft starter fault indicator H5. The PLC controller 300 then controls the fourth contactor KM4, the fifth contactor KM5, and the seventh contactor KM7 to engage, connecting the second soft starter 200 to the circuit of the first fan M1. Subsequently, it controls the second relay KA2 to engage, starting the second soft starter 200. Upon receiving a bypass output signal from the second soft starter 200, the PLC controller 300 controls the first contactor KM1 to engage. Upon receiving the signal indicating that the first contactor KM1 is engaged, it disconnects the second relay KA2, and simultaneously disconnects the fourth contactor KM4, the fifth contactor KM5, and the seventh contactor KM7 to complete the start-up. Pressing the first fan stop button SB2 extinguishes the first fan running indicator H1, and the PLC controller 300 controls the first contactor KM1 to disconnect, stopping the first fan M1.

[0064] Pressing the second fan start button SB3 illuminates the second fan's running indicator light H3. The PLC controller 300 then controls the fifth contactor KM5 and the sixth contactor KM6 to engage, subsequently controlling the second relay KA2 to engage, thus starting the second soft starter 200. Upon receiving the bypass output signal from the second soft starter 200, the PLC controller 300 controls the second contactor KM2 to engage. Upon receiving the signal indicating that the second contactor KM2 is engaged, the PLC controller 300 disconnects the second relay KA2, simultaneously disconnecting the fifth contactor KM5 and the sixth contactor KM6 to complete the start-up. Pressing the second fan stop button SB4 extinguishes the second fan's running indicator light H3. The PLC controller 300 then controls the second contactor KM2 to disconnect, stopping the second fan M2.

[0065] When the second soft starter 200 malfunctions, the second soft starter fault indicator H6 illuminates, and the control flow is as follows:

[0066] Pressing the first fan start button SB1 illuminates the first fan's running indicator light H1. The PLC controller 300 then controls the third contactor KM3 and the fourth contactor KM4 to engage. The PLC controller 300 then controls the first relay KA1 to engage, starting the first soft starter 100. Upon receiving a bypass output signal from the first soft starter 100, the PLC controller 300 controls contactor KM1 to engage. Upon receiving the signal that the first contactor KM1 is engaged, the PLC controller 300 disconnects the first relay KA1, simultaneously disconnecting the third contactor KM3 and the fourth contactor KM4 to complete the start-up. Pressing the first fan stop button SB2 extinguishes the first fan's running indicator light H1. The PLC controller 300 then controls the first contactor KM1 to disengage, stopping the second fan M2.

[0067] When the first soft starter 100 is idle, pressing the second fan start button SB3 illuminates the second fan running indicator H3. The PLC controller 300 then controls the third contactor KM3, the sixth contactor KM6, and the seventh contactor KM7 to engage, subsequently controlling the first relay KA1 to engage, thus starting the first soft starter 100. Upon receiving the bypass output signal from the first soft starter 100, the PLC controller 300 controls the second contactor KM2 to engage. Upon receiving the signal indicating the second contactor KM2 is engaged, the first relay KA1 is disconnected, simultaneously disconnecting the third contactor KM3, the sixth contactor KM6, and the seventh contactor KM7 to complete the start-up. Pressing the second fan stop button SB4 extinguishes the second fan running indicator H3, and the PLC controller 300 controls the second contactor KM2 to disengage, stopping the second fan M2.

[0068] The proposed solution in this embodiment can be further extended to a multi-fan system architecture. By constructing a distributed soft-start cluster control network based on a programmable logic controller (PLC), intelligent starting and fault redundancy switching of three or more asynchronous motors can be achieved.

[0069] Based on the original dual-fan mutual backup, a ring bus is added as a common soft start channel. Through multiple mutual backup contactors, when any one of the N fans fails, the remaining N-1 soft starters can be used as backup resources.

[0070] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A multi-fan soft-start control cabinet with mutual backup, characterized in that, The multi-fan soft-start control cabinet includes: The control switch assembly includes a main circuit breaker connected to a three-phase power supply and multiple branch circuit breakers. The output of the main circuit breaker is connected to each branch circuit breaker through multiple parallel branches. The wind turbine main circuit includes at least one backup contactor and at least two wind turbine control circuits. The wind turbine control circuits are connected to the main circuit breaker through corresponding branch circuit breakers. The soft start paths in any two wind turbine control circuits are interconnected by the backup contactor. Each wind turbine control circuit is connected to one wind turbine. The control circuit includes a PLC controller connected to the interconnecting contactor, the main circuit breaker, and the plurality of branch circuit breakers.

2. The multi-fan soft-start control cabinet according to claim 1, characterized in that, The wind turbine control circuit is configured as a first wind turbine control circuit and a second wind turbine control circuit. The first soft start path in the first wind turbine control circuit is connected to the first wind turbine, and the second soft start path in the second wind turbine control circuit is connected to the second wind turbine. The mutual backup contactor is connected across both the first soft start path and the second soft start path.

3. The multi-fan soft-start control cabinet according to claim 2, characterized in that, The first fan control circuit includes a first bypass operating path, on which a first contactor and a first thermal relay are provided. The main incoming terminal of the first contactor is connected to the corresponding branch circuit breaker, the main outgoing terminal of the first contactor is connected to the main incoming terminal of the first thermal relay, and the main outgoing terminal of the first thermal relay is connected to the first fan. The first soft start path is provided with a first soft starter and a third contactor. The main incoming terminal of the first soft starter is connected to the corresponding branch circuit breaker, the main outgoing terminal of the first soft starter is connected to the main incoming terminal of the third contactor, and the main outgoing terminal of the third contactor is connected to the first fan.

4. The multi-fan soft-start control cabinet according to claim 3, characterized in that, The second fan control circuit includes a second bypass operating path, on which a second contactor and a second thermal relay are provided. The main incoming terminal of the second contactor is connected to the corresponding branch circuit breaker, the main outgoing terminal of the second contactor is connected to the main incoming terminal of the second thermal relay, and the main outgoing terminal of the second thermal relay is connected to the second fan. The second soft starter path is provided with a second soft starter and a fifth contactor. The main incoming terminal of the second soft starter is connected to the corresponding branch circuit breaker, the main outgoing terminal of the second soft starter is connected to the main incoming terminal of the fifth contactor, and the main outgoing terminal of the fifth contactor is connected to the second fan.

5. The multi-fan soft-start control cabinet according to claim 4, characterized in that, The interconnecting contactor includes a fourth contactor, a sixth contactor, and a seventh contactor. The fourth contactor is connected between the third contactor and the first fan, and the sixth contactor is connected between the fifth contactor and the second fan. The main incoming line terminals of the fourth contactor and the sixth contactor are connected through the seventh contactor.

6. The multi-fan soft-start control cabinet according to claim 5, characterized in that, The fourth, sixth, and seventh contactors are all connected to the PLC controller.

7. The multi-fan soft-start control cabinet according to claim 4, characterized in that, The first contactor, the second contactor, the third contactor, and the fifth contactor are all connected to the PLC controller.

8. The multi-fan soft-start control cabinet according to claim 4, characterized in that, Both the first thermal relay and the second thermal relay are connected to the PLC controller.

9. The multi-fan soft-start control cabinet according to claim 4, characterized in that, The multi-fan soft-start control cabinet also includes a switching power supply, and the output terminal of the main circuit breaker is connected to the switching power supply.

10. The multi-fan soft-start control cabinet according to claim 9, characterized in that, The multi-fan soft-start control cabinet also includes a fuse, and the output terminal of the main circuit breaker is connected to the switching power supply through the fuse.

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