Fire-fighting fan control system

Abstract

The utility model discloses a fire-fighting fan control system, which comprises a microprocessor control unit connected with an uninterruptible power supply, a relay and a fire-fighting fan and used for detecting a first operation state of the uninterruptible power supply and a second operation state of the fire-fighting fan and sending a control signal to the relay according to the first operation state and the second operation state, wherein the control signal is used for controlling a power supply of the fire-fighting fan to be switched off; and the relay is connected with the uninterruptible power supply and the fire-fighting fan and is used for responding to the control signal and controlling the power supply of the fire-fighting fan to be switched off under the condition that the control signal is received. By means of the fire-fighting fan control system, the problem that in the related technology, due to the fact that the fire-fighting fan is directly connected with the external power grid, when thermal runaway happens to the energy storage container, starting and stopping control over the fire-fighting fan is inaccurate is solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of electric control and automation, and specifically relates to a fire-fighting fan control system. BACKGROUND

[0002] In modern energy storage systems, fire-fighting fans play a crucial role in the prevention and control of thermal runaway events in energy storage containers. When the temperature in the energy storage container abnormally rises or smoke accumulates, the fire-fighting fan quickly starts to reduce the heat and smoke concentration inside the energy storage container through exhaust and ventilation, thereby reducing the potential harm caused by thermal runaway.

[0003] However, in related technologies, fire-fighting fans are usually directly connected to external power grids, which means that the operation of fire-fighting fans completely depends on the stability of external power grids. When the energy storage container encounters thermal runaway, for safety reasons, the relevant emergency mechanism will cut off the connection between the fire-fighting fan and the external power grid to avoid the risk of fire spreading or electric shock. This results in the fire-fighting fan being unable to work, and cannot effectively perform exhaust cooling, thereby exacerbating the consequences of thermal runaway and prolonging the handling time of the accident, posing a direct threat to personnel safety and equipment protection.

[0004] In view of the problem in the related art that the fire-fighting fan is directly connected to the external power grid, resulting in inaccurate start-stop control of the fire-fighting fan when the energy storage container experiences thermal runaway, no effective solution has been proposed so far. SUMMARY

[0005] The utility model provides a kind of fire-fighting fan control system to at least solve the problem that the fire-fighting fan is directly connected to the external power grid, resulting in inaccurate start-stop control of the fire-fighting fan when the energy storage container experiences thermal runaway.

[0006] According to one embodiment of the utility model, a fire-fighting fan control system is provided, comprising: a microprocessor control unit connected to an uninterruptible power supply, a relay and a fire-fighting fan, for detecting a first operating state of the uninterruptible power supply and a second operating state of the fire-fighting fan, and sending a control signal to the relay according to the first operating state and the second operating state, wherein the control signal is used to control the power supply of the fire-fighting fan to be disconnected; the relay is connected to the uninterruptible power supply and the fire-fighting fan, and is used to control the power supply of the fire-fighting fan to be disconnected in response to the control signal when the control signal is received.

[0007] In one exemplary embodiment, the microprocessor control unit comprises: a first communication interface connected to a second communication interface of the uninterruptible power supply for obtaining the first operating state; and a first pin connected to a first normally closed feedback contact of the fire-fighting fan for obtaining the second operating state.

[0008] In one example embodiment, the relay comprises: a relay coil, a first end of the relay coil is connected with a second pin of a power module, a second end of the relay coil is connected with a third pin of the microprocessor control unit, wherein the fire fan control system comprises the power module; a normally closed contact, a fourth pin of the normally closed contact is connected with the uninterruptible power supply, a fifth pin of the normally closed contact is connected with the fire fan.

[0009] In one example embodiment, the microprocessor control unit is further configured to enable the third pin to connect the second end of the relay coil to a negative voltage according to the control signal; and the relay coil is further configured to generate a magnetic field under the action of a positive voltage provided by the power module and the negative voltage, and control the normally closed contact to be disconnected by the magnetic field.

[0010] In one example embodiment, the microprocessor control unit is further configured to: determine whether a running time of the fire fan reaches a first preset value when the first running state is a battery state and the second running state is a starting state; and send the control signal when it is determined that the running time of the fire fan reaches the first preset value.

[0011] In one example embodiment, the microprocessor control unit is further configured to: acquire a remaining capacity of a battery in the uninterruptible power supply and a capacity size of the container; and determine the first preset value according to the remaining capacity and the capacity size of the container.

[0012] In one example embodiment, the microprocessor control unit is further configured to: send the control signal when a first running state of the uninterruptible power supply is a battery state, a voltage of the uninterruptible power supply is lower than a second preset value, and a second running state of the fire fan is a starting state.

[0013] In one example embodiment, the uninterruptible power supply is connected with a main power supply, and is configured to: determine that a first running state of the uninterruptible power supply is a power state when the main power supply is normal; and determine that the first running state of the uninterruptible power supply is a battery state when the main power supply is abnormal.

[0014] In one example embodiment, the uninterruptible power supply, connected with the power module, is further configured to: in a case where the first running state of the uninterruptible power supply is determined as the power state, acquire AC power from the main power supply to charge a lead-acid battery inside the uninterruptible power supply, and supply power to the power module through the AC power; and in a case where the first running state of the uninterruptible power supply is determined as the battery state, supply power to the power module through the lead-acid battery.

[0015] In one example embodiment, the fire-fighting fan control system further comprises a power module, a sixth pin of the power module being connected with a seventh pin of the microprocessor control unit and a second normally closed feedback contact of the fire-fighting fan, configured to convert DC power acquired from the lead-acid battery into AC power, and provide power to the microprocessor control unit through the AC power, wherein the first normally closed feedback contact is connected with the second normally closed feedback contact.

[0016] The fire-fighting fan control system of the utility model, comprising: microprocessor control unit, for detecting the first running state of the uninterruptible power supply and the second running state of the fire-fighting fan, and sending control signal to the relay according to the first running state and the second running state, wherein the control signal is used to control the power of the fire-fighting fan to be disconnected;The relay is used to control the power of the fire-fighting fan to be disconnected in response to the control signal in the case of receiving the control signal.Through the above-mentioned fire-fighting fan control system, the automatic closing of the fire-fighting fan can be realized, unnecessary power waste is avoided, and the problem that the start-stop control of the fire-fighting fan is inaccurate due to the direct connection of the fire-fighting fan with the external power grid in the related art is solved. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is a circuit diagram of the fire-fighting fan control system of the utility model (one);

[0018] Figure 2 It is a circuit diagram of the fire-fighting fan control system of the utility model (two);

[0019] Figure 3 It is a working principle schematic diagram of the microprocessor control unit in the fire-fighting fan control system of the utility model;

[0020] Figure 4 It is a working principle schematic diagram of the relay in the fire-fighting fan control system of the utility model. DETAILED DESCRIPTION

[0021] The embodiments of the utility model will be described in detail below with reference to the drawings and in combination with the embodiments.

[0022] It should be noted that the terms "first", "second" and the like in the description and claims of the utility model and the above drawings are used to distinguish similar objects, and do not necessarily be used to describe a particular order or sequence.

[0023] The utility model provides a kind of circuit diagram of fire-fighting fan control system, Figure 1 It is according to the circuit diagram of fire-fighting fan control system of the utility model embodiment (one), as Figure 1 As shown, the circuit includes the following:

[0024] Microprocessor control unit 12 is connected with uninterrupted power supply 16, relay 14 and fire-fighting fan 18, for detecting the first operating state of the uninterrupted power supply 16 and the second operating state of the fire-fighting fan 18, and according to the first operating state and the second operating state, control signal is sent to the relay 14, wherein, the control signal is used to control the power supply of the fire-fighting fan 18 is disconnected;

[0025] The relay 14 is connected with the uninterrupted power supply 16 and the fire-fighting fan 18, for the power supply of the fire-fighting fan 18 is disconnected under the condition of receiving the control signal, in response to the control signal.

[0026] Through the above-mentioned fire-fighting fan control system, the automatic closing of fire-fighting fan can be realized, unnecessary power waste is avoided, and the problem that the start-stop control of fire-fighting fan is inaccurate due to the direct connection of fire-fighting fan with external power grid in the related art is solved.

[0027] In one exemplary embodiment, the microprocessor control unit comprises: a first communication interface connected with the second communication interface of the uninterrupted power supply, for obtaining the first operating state;First pin is connected with the first normally closed feedback contact of the fire-fighting fan, for obtaining the second operating state.

[0028] The working principle of microprocessor control unit is as shown in Figure 3As shown, the first communication interface in the microprocessor-based control unit (MBCU) corresponds to the second communication interface in the uninterruptible power supply (UPS), and the two establish a communication connection through the communication interface, so that the MBCU can obtain the first running state information of the UPS in real time. The first running state information generally refers to the working mode of the UPS, such as whether it is in a mains power supply state, a battery power supply state, or a fault state. This real-time communication capability ensures that the MBCU can timely understand the running condition of the UPS, which is crucial for accurately controlling the fire fan.

[0029] Secondly, the first pin of the MBCU is physically connected with the first normally closed feedback contact on the fire fan. The state of the fire fan is monitored through the first pin, so that the MBCU can obtain the second running state information of the fire fan, i.e., whether the fire fan is currently running. When the fire fan starts, the first normally closed feedback contact inside the fire fan will be closed, forming a path, thereby transmitting a signal to the MBCU, indicating that the fire fan is working. Conversely, if the fire fan stops running, the contact will be separated, and the MBCU will receive a different signal indicating that the fire fan has been turned off.

[0030] In an exemplary embodiment, the relay comprises: a relay coil, a first end of the relay coil being connected with a second pin of a power module, a second end of the relay coil being connected with a third pin of the microprocessor-based control unit, wherein the fire fan control system comprises the power module; a normally closed contact, a fourth pin of the normally closed contact being connected with the uninterruptible power supply, a fifth pin of the normally closed contact being connected with the fire fan.

[0031] In an exemplary embodiment, the microprocessor-based control unit is further configured to enable the third pin according to the control signal to connect the second end of the relay coil to a negative voltage; and the relay coil is further configured to generate a magnetic field under the action of a positive voltage provided by the power module and the negative voltage, and control the normally closed contact to be disconnected through the magnetic field.

[0032] The working principle diagram of the relay is as follows: Figure 4As shown, the core of the relay is the relay coil, which is an electromagnetic coil that generates a magnetic field when current passes through it. In this embodiment, the first end of the relay coil is connected to the second pin of the power module, which means that the activation of the relay (i.e. the energization of the coil) is directly powered by the power module. The second end of the relay coil is connected to the third pin of the MBCU, which can activate the relay coil by controlling the level state of the third pin. Specifically, when the MBCU wants to disconnect the power supply of the fire fan, it sends a control signal to the third pin to enable the third pin, thereby connecting the second end of the relay coil to the negative voltage. When the first end of the relay coil (positive voltage from the power module) and the second end of the relay coil (negative voltage connected under the control of the MBCU) act on the coil at the same time, an electromagnetic field will be generated inside the coil. This electromagnetic field is sufficient to drive the normally closed contact inside the relay to change state, switching from the closed state to the open state. The fourth pin of the normally closed contact is directly connected to the UPS, while the fifth pin is connected to the fire fan. When the relay coil is not activated, the normally closed contact is in the closed state, ensuring that the power supply path from the UPS to the fire fan is continuous. Once the MBCU enables the third pin, causing a sufficient voltage difference across the coil to form an electromagnetic field, the normally closed contact will quickly open, thereby cutting off the power supply to the fire fan and achieving automatic stopping of the fire fan.

[0033] In an exemplary embodiment, the microprocessor control unit is further configured to: in the case that the first operating state is the battery state and the second operating state is the start state, determine whether the running time of the fire fan reaches a first preset value; and in the case that the running time of the fire fan reaches the first preset value, send the control signal.

[0034] The MBCU continuously monitors two key state parameters in the system: one is the first operating state of the UPS, i.e. its working mode; the other is the second operating state of the fire fan, i.e. whether it has been started or not. After confirming that the UPS is in battery power supply mode and the fire fan has been started, the MBCU begins to assess whether the running time of the fire fan has reached a pre-set first preset value. Once the MBCU determines that the running time of the fire fan reaches the first preset value, it will send a control signal. The purpose of this control signal is to enable the third pin of the microprocessor control unit, thereby controlling the relay coil to generate an electromagnetic field, causing the normally closed contact of the relay to open, and ultimately leading to the power supply of the fire fan being cut off and the fire fan stopping running.

[0035] In an exemplary embodiment, the microprocessor control unit is further configured to: obtain the remaining capacity of the battery in the uninterruptible power supply and the capacity of the container; and determine the first preset value based on the remaining capacity and the capacity of the container.

[0036] The MBCU will obtain the remaining battery capacity information of the UPS internal battery, as well as the capacity size data of the energy storage container. These information is crucial for assessing the power consumption speed and the severity of the thermal runaway event. Based on the obtained UPS battery remaining capacity and the capacity size of the container, the MBCU will dynamically calculate a first preset value that is most suitable for the current situation. The first preset value will ensure that the UPS power resources are protected while the fire-fighting fan has enough running time to handle the thermal runaway event in the container. For example, for larger energy storage containers, the preset value may be set higher at the same battery capacity to allow the fire-fighting fan to run longer, ensuring effective evacuation of internal heat and smoke.

[0037] In an exemplary embodiment, the microprocessor control unit is further configured to: in the case that the first operating state of the uninterruptible power supply is a battery state, the voltage of the uninterruptible power supply is lower than a second preset value, and the second operating state of the fire-fighting fan is a start state, send the control signal.

[0038] When the MBCU detects that the UPS is in the battery state (meaning that the UPS is currently powered by the internal battery rather than the external power grid), and the output voltage of the UPS is lower than the second preset value (which indicates that the battery capacity is tight and may not be sufficient to support the operation of all systems for a long time), and the fire-fighting fan is in the start state, the MBCU will immediately send a control signal. The purpose of this signal is to enable the third pin of the microprocessor control unit, thereby controlling the relay coil to generate an electromagnetic field, causing the normally closed contact of the relay to open, ultimately causing the power supply of the fire-fighting fan to be cut off and the fire-fighting fan to stop running. Thus, when the UPS power is close to a dangerous level, the UPS can be quickly protected to prevent its complete failure due to over-discharge.

[0039] In summary, before sending the control signal, the MBCU will consider multiple factors, including but not limited to the operating state of the UPS, the power condition and the operating state of the fire-fighting fan. This instant reaction capability under complex conditions is a manifestation of the intelligence of the MBCU. It can automatically intervene in the operation of the fire-fighting fan at a critical moment when the UPS power is low enough to affect the overall safety of the system, ensuring that the core functions of the UPS are given priority protection.

[0040] In an exemplary embodiment, the uninterruptible power supply is connected to a main power source, and is configured to: in the case that the main power source is normal, determine that the first operating state of the uninterruptible power supply is a power state; in the case that the main power source is abnormal, determine that the first operating state of the uninterruptible power supply is a battery state.

[0041] In an exemplary embodiment, the uninterruptible power supply, connected with the power module, is further configured to: in a case where the first running state of the uninterruptible power supply is determined as the power state, acquire alternating current from the main power supply to charge a lead-acid battery inside the uninterruptible power supply, and supply power to the power module through the alternating current; in a case where the first running state of the uninterruptible power supply is determined as the battery state, supply power to the power module through the lead-acid battery.

[0042] The UPS is connected with a main power supply (such as a power grid), and is designed to allow it to take different running modes when the main power supply is normal and when it is abnormal, so as to ensure the continuity and stability of power supply. When the main power supply is stable and in a normal operating range, the UPS can determine that the main power supply is normal through its built-in circuit, and automatically switch to the power state. In this mode, the UPS acquires alternating current (220Vac) from the main power supply, which is directly used to supply power to the loads in the circuit, such as the fire fan and the power module, to ensure their normal operation; on the other hand, the UPS uses this part of stable alternating current to charge the internal lead-acid battery, to maintain the full state of the battery, so as to immediately switch to the battery power supply mode when the main power supply is abnormal.

[0043] When the main power supply fails, such as power failure, voltage drop, and other abnormal conditions, the UPS automatically determines to enter the battery state. In this mode, the UPS no longer acquires power from the main power supply, but immediately enables the internal lead-acid battery as a power supply to provide power support for the key loads and the power module in the circuit. This instantaneous switching capability ensures that the key equipment in the circuit, such as the fire fan, can still run uninterruptedly when the power grid fails.

[0044] In an exemplary embodiment, the fire fan control system further comprises a power module, a sixth pin of the power module is connected with a seventh pin of the microprocessor control unit and a second normally closed feedback contact of the fire fan, for converting direct current acquired from the lead-acid battery into alternating current, and providing power to the microprocessor control unit through the alternating current, wherein the first normally closed feedback contact is connected with the second normally closed feedback contact.

[0045] The power module establishes a connection with the seventh pin of the MBCU through its sixth pin. When the UPS is in a battery-powered state, the power module is responsible for converting the direct current obtained from the internal lead-acid battery of the UPS into alternating current. This process is achieved through the inverter circuit inside the power module, which converts the direct current of the lead-acid battery into alternating current and transmits the converted alternating current to the MBCU to provide the power required for its operation. This design ensures that the MBCU remains active even in the event of a power grid outage, performing its monitoring and control tasks, including but not limited to monitoring the UPS status, the operation status of the fire fan, and making corresponding control decisions.

[0046] Obviously, the above-described embodiments are only a part of the embodiments of the present application, not all. In order to better understand the above-mentioned fire fan control system, the following embodiments are described, but not used to limit the technical scheme of the embodiments of the present application, specifically:

[0047] Specifically, the circuit diagram (two) of the fire fan control system provided by the present application is shown as Figure 2 The circuit includes the following:

[0048] The circuit includes the following:

[0049] Firstly, the L end of the 220Vac input power (equivalent to the main power supply) is connected to the L (INPUT) pin of the UPS, the N end of the 220Vac input power is connected to the N (INPUT) pin of the UPS, and the PE end of the 220Vac input power is connected to the PE pin of the UPS, forming a stable power input channel. The UPS serves as a power conversion center, with its L (OUTPUT) pin connected to the TB1-3 pin of the 24V power module and the normally closed contact 1 pin (equivalent to the fourth pin) of the relay KM1, the N (OUTPUT) pin of the UPS connected to the TB1-2 pin of the 24V power module and the normally closed contact 4 pin (equivalent to the fourth pin) of the relay KM1, the PE pin of the UPS connected to the TB1-1 pin of the 24V power module, the + pin of the UPS connected to the + pin of the lead-acid battery, and the - pin of the UPS connected to the - pin of the lead-acid battery. The above connection relationship between the loads ensures that the UPS obtains alternating current from the main power supply to power the connected loads and charge the lead-acid battery when the 220Vac main power supply is normal. In the case of abnormal 220Vac main power supply, the load is powered by the lead-acid battery.

[0050] Further, the B-pin of the UPS is connected to the B4-pin of the MBCU, and the A+ pin of the UPS is connected to the A4-pin of the MBCU. The MBCU obtains the first running state of the UPS through the A4-pin and the B4-pin (equivalent to the first communication interface). The TB2-3 pin (equivalent to the sixth pin) of the 24V power module is connected to the normally closed feedback contact C pin (equivalent to the second normally closed feedback contact) of the fire fan and the GND, COMA, DO1- pin (equivalent to the seventh pin) of the MBCU, and the DIA1 pin (equivalent to the first pin) of the MBCU is connected to the normally closed feedback contact NC pin (equivalent to the first normally closed feedback contact) of the fire fan, wherein the normally closed feedback contact C and the normally closed feedback contact NC pin of the fire fan are connected, and therefore the MBCU can obtain the second running state of the fire fan through the DIA1 pin. Optionally, in the case that the first running state of the UPS is the battery state and the second running state of the fire fan is the starting state, the MBCU determines whether the running time of the fire fan reaches a first preset value, and in the case that the running time of the fire fan reaches the first preset value, the MBCU sends a control signal to the relay KM1. Alternatively, in the case that the first running state of the UPS is the battery state, the voltage of the UPS is lower than a second preset value, and the second running state of the fire fan is the starting state, the MBCU immediately sends a control signal to the relay KM1.

[0051] On the other hand, the TB2-1 pin (equivalent to the second pin) of the 24V power module is connected to the coil 14 pin (equivalent to the first end) of the relay KM1 and the +V pin of the MBCU, for providing a positive voltage to the MBCU and the coil 14 pin of the relay KM1. The DO1+ pin (equivalent to the third pin) of the MBCU is connected to the 13 pin (equivalent to the second end) of the relay coil, and in the case that the MBCU sends a control signal, the DO1+ pin of the MBCU is enabled, so that the 13 pin of the relay coil is connected to a negative voltage, at this time the relay coil is energized, and an electromagnetic field is generated inside the coil. The normally closed contact 9 pin (equivalent to the fifth pin) of the relay KM1 is connected to the L pin of the fire fan, and the normally closed contact 12 pin (equivalent to the fifth pin) of the relay KM1 is connected to the N pin of the fire fan, under the action of the electromagnetic field, the normally closed contact 9 pin and the normally closed contact 12 pin are switched from the closed state to the open state, finally the power supply of the fire fan is cut off, and the fire fan stops running.

[0052] The preferred embodiments of the present application have been described above, but the present application is not limited to the above-mentioned embodiments, and various modifications and changes can be made by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the principles of the present application shall be included in the protection scope of the present application.

Claims

1. A fire fan control system, characterized by, The application relates to a fire-fighting fan control system. The microprocessor control unit is connected with an uninterruptible power supply, a relay and a fire-fighting fan, is used for detecting a first running state of the uninterruptible power supply and a second running state of the fire-fighting fan, and sends a control signal to the relay according to the first running state and the second running state, wherein the control signal is used for controlling power supply disconnection of the fire-fighting fan. The relay is connected with the uninterruptible power supply and the fire-fighting fan, and is used for controlling power supply disconnection of the fire-fighting fan in response to the control signal when the control signal is received.

2. The fire fan control system of claim 1, wherein, The microprocessor control unit comprises: A first communication interface is connected with a second communication interface of the uninterruptible power supply, and is used for acquiring the first running state. A first pin is connected with a first normally-closed feedback contact of the fire-fighting fan, and is used for acquiring the second running state.

3. The fire fan control system of claim 1, wherein, The relay comprises: A relay coil, a first end of the relay coil is connected with a second pin of a power module, and a second end of the relay coil is connected with a third pin of the microprocessor control unit, wherein the fire-fighting fan control system comprises the power module; A normally-closed contact, a fourth pin of the normally-closed contact is connected with the uninterruptible power supply, and a fifth pin of the normally-closed contact is connected with the fire-fighting fan.

4. The fire fan control system of claim 3, wherein, The microprocessor control unit is further used for enabling the third pin to connect the second end of the relay coil to a negative voltage according to the control signal. The relay coil is further used for generating a magnetic field when a positive voltage provided by the power module and the negative voltage simultaneously act, and the normally-closed contact is controlled to be disconnected through the magnetic field. The microprocessor control unit is further used for:

5. The fire fan control system of claim 1, wherein, In the case that the first running state is a battery state and the second running state is a starting state, determining whether the running time of the fire-fighting fan reaches a first preset value; In the case that it is determined that the running time of the fire-fighting fan reaches the first preset value, the control signal is sent. The microprocessor control unit is further used for:

6. The fire fan control system of claim 5, wherein, Acquiring the residual capacity of a battery in the uninterruptible power supply and the capacity size of a container; According to the residual capacity and the capacity size of the container, the first preset value is determined. The microprocessor control unit is further used for:

7. The fire fan control system of claim 1, wherein, In the case that the first running state of the uninterruptible power supply is a battery state, the voltage of the uninterruptible power supply is lower than a second preset value, and the second running state of the fire-fighting fan is a starting state, the control signal is sent. The uninterruptible power supply is connected with a main power supply, and is used for:

8. The fire fan control system of claim 1, wherein, In the case that the main power supply is normal, determining that the first running state of the uninterruptible power supply is a power supply state; In the case that the main power supply is abnormal, determining that the first running state of the uninterruptible power supply is a battery state. The uninterruptible power supply is connected with a power module, and is further used for:

9. The fire fan control system of claim 8, wherein, In the case that it is determined that the first running state of the uninterruptible power supply is the power supply state, acquiring alternating current from the main power supply to charge a lead-acid storage battery inside the uninterruptible power supply, and supplying power to the power module through the alternating current. ​ In a case where the first operating state of the uninterruptible power supply is determined as the battery state, power is supplied to the power module by the lead-acid battery.

10. The fire fan control system of claim 2, wherein, The fire-fighting fan control system further comprises: The power module has a sixth pin connected with a seventh pin of the microprocessor control unit and a second normally closed feedback contact of the fire-fighting fan, and is configured to convert direct current obtained from the lead-acid battery into alternating current, and provide power for the microprocessor control unit by the alternating current, wherein the first normally closed feedback contact is connected with the second normally closed feedback contact.

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