Fan control method, device and system, fan and equipment

Abstract

The invention discloses a fan control method, device and system, a fan and equipment, and belongs to the field of fan starting. The draught fan control method comprises the steps that before a draught fan is started, the state of the draught fan is obtained; when the draught fan is in the upwind state, the upwind rotating speed of the draught fan is obtained; and when the upwind rotating speed is larger than or equal to the preset rotating speed, a first switch tube in each phase of a three-phase inverter of the fan is controlled to be switched off, and a second switch tube is controlled to be switched on intermittently, so that braking is conducted. According to the scheme, before the draught fan is started, whether the draught fan is in the headwind state or not is judged firstly, and when the draught fan is in the headwind state, the draught fan inverter is controlled according to the headwind rotating speed so as to brake the draught fan. It is ensured that the draught fan is not in a headwind state before starting, the problem of out-of-step or overcurrent protection during starting is avoided, and it is ensured that the draught fan is successfully started. And when the against-wind rotating speed is relatively high, the second switch tube is controlled to be closed intermittently, so that the winding is prevented from being damaged due to overheat caused by overhigh current in the braking process.

Description

Technical Field

[0001] The present application relates to the technical field of fan startup, and in particular, to a fan control method, device, system, fan, and equipment. Background Art

[0002] Axial flow fans are an important component of the air-conditioning system of new energy buses. Currently, most domestic new energy bus air-conditioning systems use traditional DC brush motors. DC brush motors require commutation, which easily generates sparks and has carbon brush wear that requires frequent maintenance.

[0003] In recent years, with the growing trend toward low-carbon, environmentally friendly, and intelligent vehicles, mid- to high-end new energy bus air conditioning systems have gradually adopted brushless axial flow fans for improved performance. Existing new energy bus air conditioning systems use multiple brushless axial flow fans in parallel on the condenser side. These brushless fans experience startup delays, and when the air conditioning is turned on while the vehicle is traveling at high speed, the fans generate negative pressure, causing them to start at high speed against the wind. If the fans are started normally in this situation, the initial speed is unknown, and direct startup can result in loss of step or overcurrent protection, significantly reducing the startup success rate. Summary of the Invention

[0004] In order to overcome the deficiencies of the prior art, the present application provides a fan control method, device, system, fan and equipment to solve the problem in the prior art that the fan may lose step or have overcurrent protection at the upwind starting point, and the fan cannot be started.

[0005] The technical solution adopted by this application to solve its technical problems is:

[0006] In a first aspect, a fan control method is provided, comprising:

[0007] Before the fan is started, obtaining the fan status;

[0008] When the fan is in a headwind state, obtaining the headwind rotation speed of the fan;

[0009] When the headwind speed is greater than or equal to a preset speed, the first switch tube in each phase of the three-phase inverter of the wind turbine is controlled to be disconnected and the second switch tube is intermittently closed to perform braking.

[0010] As an optional implementation of the present application, controlling the second switch tube to be intermittently closed includes:

[0011] After each time the second switch tube is controlled to be closed for a first preset time, the second switch tube is controlled to be opened for a second preset time;

[0012] After the second switch tube is controlled to be off for the second preset time period, the second switch tube is controlled to be on for the first preset time period until the headwind speed is 0.

[0013] As an optional implementation of this application, the following is also included:

[0014] The first preset duration and the second preset duration are the same in each cycle;

[0015] Among them, one cycle is that the second switch tube is closed for a first preset time and then opened for a second preset time; the greater the headwind speed, the shorter the first preset time; and / or, the greater the headwind speed, the longer the second preset time.

[0016] As an optional implementation of this application, the following is also included:

[0017] The first preset duration of the current cycle is greater than the first preset duration of the previous cycle, and / or the second preset duration of the current cycle is less than the second preset duration of the previous cycle;

[0018] One cycle is when the second switch is closed for a first preset time and then opened for a second preset time.

[0019] As an optional implementation of this application, the following is also included:

[0020] When the headwind speed is less than a preset speed, the first switch tube in each phase of the three-phase inverter of the wind turbine is controlled to be disconnected and the second switch tube is closed until the headwind speed is 0.

[0021] As an optional implementation of the present application, obtaining the wind turbine status includes:

[0022] Obtaining a back electromotive force voltage of the fan;

[0023] If the back electromotive force voltage is not 0, it is determined that the fan is in a headwind state.

[0024] As an optional implementation of the present application, obtaining the upwind speed of the fan includes:

[0025] Obtaining a back electromotive force voltage of the fan;

[0026] Calculating a back electromotive force frequency based on the back electromotive force voltage, wherein the back electromotive force voltage is proportional to the back electromotive force frequency;

[0027] The upwind rotation speed of the fan is determined based on the back electromotive force frequency, and the upwind rotation speed is inversely proportional to the back electromotive force frequency.

[0028] In a second aspect, a fan control device is provided, comprising:

[0029] A fan status acquisition module is used to acquire the fan status before the fan is started;

[0030] A headwind speed acquisition module, configured to acquire the headwind speed of the fan when the fan is in a headwind state;

[0031] The switch tube control module is used to control the first switch tube in each phase of the three-phase inverter of the wind turbine to be disconnected and the second switch tube to be intermittently closed when the headwind speed is greater than or equal to the preset speed, so as to perform braking.

[0032] In a third aspect, a wind turbine control system is provided, comprising:

[0033] at least one processor and at least one memory;

[0034] The memory stores executable instructions of the processor;

[0035] The processor is configured to be used for any one of the wind turbine control methods described above.

[0036] In a fourth aspect, a wind turbine is provided, applying any of the wind turbine control methods described above.

[0037] In a fifth aspect, an electrical device is provided, comprising the above-mentioned fan.

[0038] Beneficial effects:

[0039] The technical solution of the present application provides a fan control method, device, system, fan and equipment. Among them, the fan control method includes: obtaining the fan status before the fan is started; when the fan is in the headwind state, obtaining the headwind speed of the fan; when the headwind speed is greater than or equal to the preset speed, controlling the first switch tube in each phase of the three-phase inverter of the fan to be disconnected and the second switch tube to be intermittently closed to perform braking. That is, before the fan is started, the present application solution first determines whether the fan is in the headwind state. When it is in the headwind state, the fan inverter is controlled according to the headwind speed to brake the fan. Ensure that the fan is not in the headwind state before starting, avoid the problem of loss of step or overcurrent protection during startup, and ensure that the fan starts successfully. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0041] Figure 1 This is a flow chart of a fan control method provided in an embodiment of the present application;

[0042] Figure 2This is a flow chart of a specific fan control method provided in an embodiment of the present application;

[0043] Figure 3 This is a circuit schematic diagram of a wind turbine headwind braking system provided by an embodiment of the present application;

[0044] Figure 4 This is another specific flow chart of a fan control method provided in an embodiment of the present application;

[0045] Figure 5 This is a schematic structural diagram of a fan control device provided in an embodiment of the present application;

[0046] Figure 6 This is a schematic diagram of the structure of a fan control system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0047] To make the purpose, technical solutions, and advantages of this application more clear, the technical solutions of this application are described in detail below with reference to the accompanying drawings and examples. Obviously, the described embodiments are only some of the embodiments of this application, rather than all of them. Based on the embodiments in this application, all other implementation methods obtained by ordinary technicians in this field without making any creative work are within the scope of protection of this application.

[0048] Reference Figure 1 and Figure 2 , an embodiment of the present application provides a wind turbine control method, comprising:

[0049] S11: Before the fan is started, the fan state is obtained; wherein the fan state includes a headwind state and a stationary state, the headwind state indicates that the fan is rotating (including clockwise rotation and counterclockwise rotation), and the stationary state indicates that the fan is not rotating.

[0050] In one embodiment, obtaining the wind turbine status includes:

[0051] Obtaining a back electromotive force voltage of the fan;

[0052] If the back electromotive force voltage is not 0, it is determined that the fan is in a headwind state.

[0053] It is understandable that when the fan is not rotating, there is no back electromotive force. Therefore, whether the back electromotive force is 0 can be used to determine whether the fan is in a headwind state.

[0054] In another embodiment, obtaining the fan status includes using a sensor to detect whether the fan blades are rotating. However, using a sensor is costly and requires detecting the blade rotation direction (i.e., clockwise or counterclockwise) as well as the fan speed, requiring a relatively complex processing procedure.

[0055] S12: When the fan is in a headwind state, obtaining a headwind rotation speed of the fan;

[0056] When the back electromotive force voltage is used to determine the state, the headwind speed of the fan is taken, including:

[0057] Obtaining a back electromotive force voltage of the fan;

[0058] Calculating a back electromotive force frequency based on the back electromotive force voltage, wherein the back electromotive force voltage is proportional to the back electromotive force frequency;

[0059] The upwind rotation speed of the fan is determined based on the back electromotive force frequency, and the upwind rotation speed is inversely proportional to the back electromotive force frequency.

[0060] S13: When the headwind speed is greater than or equal to a preset speed, the first switch tube in each phase of the three-phase inverter of the wind turbine is controlled to be disconnected and the second switch tube is intermittently closed to perform braking.

[0061] For example, a three-phase inverter such as Figure 3 The three-phase full-bridge circuit shown here includes two switches per phase. It should be noted that this hardware structure represents the existing fan drive structure (i.e., the circuit used after startup). The improvement presented in this application is to use this circuit to brake the fan before startup. Furthermore, the first switch referred to in this application can be any switch in each phase.

[0062] In one embodiment, when the headwind speed is less than a preset speed, the first switching tube in each phase of the three-phase inverter of the wind turbine is controlled to be off and the second switching tube is closed until the headwind speed reaches 0. When the headwind speed is less than the preset speed, the headwind speed is relatively low, and braking can be initiated directly without intermittent braking. Therefore, even if braking is continued, heat generation is minimal and winding burnout is unlikely.

[0063] Of course, to ensure safety, in another embodiment, when the headwind speed is less than the preset speed, intermittent braking can still be performed, that is, the first switch tube in each phase of the three-phase inverter of the wind turbine is controlled to be disconnected and the second switch tube is intermittently closed to perform braking.

[0064] It should be noted that when continuous braking is used when the headwind speed is less than a preset speed and intermittent braking is used when the headwind speed is greater than or equal to the preset speed, if intermittent braking is used, the intermittent braking control method can be used until the headwind speed reaches 0. That is, when the headwind speed is greater than or equal to the preset speed, the first switching tube in each phase of the three-phase inverter of the wind turbine is controlled to be disconnected and the second switching tube is intermittently closed until the headwind speed reaches 0.

[0065] Alternatively, the current headwind speed is re-detected after each intermittent braking cycle or a preset number of cycles, and then the control scheme is determined based on the current headwind speed. Therefore, after intermittent braking, the headwind speed will decrease, and then there may be a situation where the headwind speed changes from being greater than or equal to the preset speed to being less than the preset speed. In this case, the continuous braking scheme can be directly adopted. That is:

[0066] When the headwind speed is greater than or equal to the preset speed, the first switch tube in each phase of the three-phase inverter of the fan is controlled to be disconnected and the second switch tube is intermittently closed until the headwind speed is less than the preset speed; when the real-time headwind speed is less than the preset speed, the first switch tube in each phase of the three-phase inverter of the fan is controlled to be disconnected and the second switch tube is closed until the headwind speed is 0.

[0067] As a preferred implementation of the present application, controlling the second switch tube to be intermittently closed includes:

[0068] After each time the second switch tube is controlled to be closed for a first preset time, the second switch tube is controlled to be opened for a second preset time;

[0069] After the second switch tube is controlled to be off for the second preset time period, the second switch tube is controlled to be on for the first preset time period until the headwind speed is 0.

[0070] In one embodiment, the first preset duration and the second preset duration of each cycle are the same;

[0071] Among them, one cycle is that the second switch tube is closed for a first preset time and then opened for a second preset time; the greater the headwind speed, the shorter the first preset time; and / or, the greater the headwind speed, the longer the second preset time.

[0072] Because the higher the headwind speed, the greater the current after the second switch is closed. To avoid burning the winding, the closing time needs to be shorter, that is, the shorter the first preset time. Similarly, for the same closing time, the heat generation is higher, so the longer the opening time for heat dissipation is required, that is, the longer the second preset time is.

[0073] However, in practice, as the second switch is continuously closed, the headwind speed will gradually decrease. If the first preset duration of each closing is the same, the overall control time before startup will be too long. Therefore, in another embodiment, the first preset duration of the current cycle is greater than the first preset duration of the previous cycle, and / or the second preset duration of the current cycle is less than the second preset duration of the previous cycle;

[0074] One cycle is when the second switch is closed for a first preset time and then opened for a second preset time.

[0075] That is, as the headwind speed decreases, the current decreases. The first preset duration can be gradually increased to increase the braking time and quickly reduce the fan speed. As the current decreases, the heat generation also decreases accordingly. Therefore, the second preset duration can be gradually decreased. This ensures the reliability of the fan while speeding up the braking process and reducing the braking time, facilitating a quick start of the fan.

[0076] The fan control method provided in the embodiment of the present application obtains the fan status before the fan is started; when the fan is in the headwind state, obtains the headwind speed of the fan; when the headwind speed is greater than or equal to the preset speed, controls the first switch tube in each phase of the three-phase inverter of the fan to be disconnected and the second switch tube to be intermittently closed to perform braking. That is, before the fan is started, the present application scheme first determines whether the fan is in the headwind state. When it is in the headwind state, the fan inverter is controlled according to the headwind speed to brake the fan. It ensures that the fan is not in the headwind state before starting, avoids the problem of loss of step or overcurrent protection during startup, and ensures that the fan starts successfully. And when the headwind speed is large, the second switch tube is controlled to be intermittently closed to ensure that during the braking process, the current is not too large, causing the winding to be damaged due to overheating.

[0077] In order to more clearly illustrate the present application, the following is provided: Figure 3 Another specific fan control method is provided as follows:

[0078] Close the inverter's upper bridge arm switches S1, S2, and S3. If the motor has a certain initial speed, the kinetic energy of the moving motor rotor will form a braking current in the short-circuited inverter bridge loop through the back electromotive force, and the motor will brake quickly.

[0079] According to the back electromotive force formula E=NBSω, it can be seen that the back electromotive force E is proportional to the angular velocity ω, and ω=2πFN, it can be seen that the angular velocity ω is proportional to the frequency FN; and through the formula E=4.44·FN·N·ф, where N and Φ are constants, it can be seen that the back electromotive force E is proportional to the frequency FN; through the back electromotive force detection circuit, the three-way back electromotive force voltage is sampled to obtain the back electromotive force voltage and frequency, and its headwind speed n can be determined. Before the fan starts, any two back electromotive forces of the motor are collected, and the motor's wire back electromotive force is calculated based on the two back electromotive forces, and the headwind speed is determined based on the back electromotive force.

[0080] The meanings of the parameters mentioned above are as follows:

[0081] E: induced electromotive force (unit: volt V);

[0082] N: number of coil turns;

[0083] B: magnetic induction intensity (unit: Tesla T);

[0084] S: The effective area of ​​the coil (in square meters) 2 );

[0085] ω: angular velocity (in radians per second rad / s)

[0086] FN: is the back electromotive force frequency (unit: Hz);

[0087] Ф: magnetic flux.

[0088] like Figure 4 As shown:

[0089] 1. When the fan is at low speed and against the wind, that is, 0<n<N1, all lower bridge arm switches are disconnected and all upper bridge arm switches are closed for time T1, performing short-circuit continuous braking.

[0090] 2. When the fan is at medium and high speed against the wind, and N1≤n<N2, all lower bridge arm switches are disconnected and all upper bridge arm switches are closed for time T2, performing short-circuit continuous braking.

[0091] 3. When the fan is operating at high speed against headwind (n ≥ N2), all lower-arm switches are disconnected, and all upper-arm switches are closed for time T3 and opened for time T4 per cycle, performing intermittent, step-by-step short-circuit braking. This means the headwind speed is re-checked after each cycle, and the control strategy is determined based on the current headwind speed period.

[0092] Among them, the relationship between T1 and T2 is T1<T2, because the higher the headwind speed is, the longer the braking time is required, that is, the longer the switch closing time is required.

[0093] T3 and T4 can be preset according to actual conditions and have no size relationship.

[0094] In the current existing rotor positioning method scheme for headwind rotation, if a strong headwind is encountered and the motor is in a continuous braking state for a long time, a large current will be generated in the stator winding for a long time, causing the motor winding to overheat and burn out.

[0095] The present application scheme ensures that the fan system can reach zero speed by, before the fan starts, regardless of whether the fan blades are rotating forward or reverse under the action of external force, and after receiving the start-up command, processing the braking according to the severity of the headwind state. The method includes: sampling the back electromotive force of the fan, determining different braking times according to the magnitude of the back electromotive force, and the braking time can be preset as a continuous or intermittent time according to the severity of the headwind state. By presetting the continuous or intermittent braking time, the continuous braking current of the fan is reduced, the temperature rise of the motor winding is prevented, and it is ensured that the motor winding will not overheat and burn out, and the air conditioner will not report a fault and shut down, thereby improving the safety and reliability of the air conditioner fan. The control method of the present invention can avoid the winding from burning due to overheating when the motor starts, extend the working life of the fan, and ensure the normal use of the air conditioner.

[0096] Based on the same inventive concept, Figure 5 As shown, the present application also provides a fan control device, comprising:

[0097] The fan status acquisition module 51 is used to obtain the fan status before the fan is started; wherein the fan status includes a headwind state and a stationary state. The headwind state indicates that the fan is rotating (including clockwise rotation and counterclockwise rotation), and the stationary state indicates that the fan is not rotating.

[0098] In one embodiment, obtaining the wind turbine status includes:

[0099] Obtaining a back electromotive force voltage of the fan;

[0100] If the back electromotive force voltage is not 0, it is determined that the fan is in a headwind state.

[0101] It is understandable that when the fan is not rotating, there is no back electromotive force. Therefore, whether the back electromotive force is 0 can be used to determine whether the fan is in a headwind state.

[0102] In another embodiment, obtaining the fan status includes using a sensor to detect whether the fan blades are rotating. However, using a sensor is costly and requires detecting the blade rotation direction (i.e., clockwise or counterclockwise) as well as the fan speed, requiring a relatively complex processing procedure.

[0103] A headwind speed acquisition module 52 is configured to acquire the headwind speed of the fan when the fan is in a headwind state;

[0104] When the back electromotive force voltage is used to determine the state, the headwind speed of the fan is taken, including:

[0105] Obtaining a back electromotive force voltage of the fan;

[0106] Calculating a back electromotive force frequency based on the back electromotive force voltage, wherein the back electromotive force voltage is proportional to the back electromotive force frequency;

[0107] The upwind rotation speed of the fan is determined based on the back electromotive force frequency, and the upwind rotation speed is inversely proportional to the back electromotive force frequency.

[0108] The switch tube control module 53 is used to control the first switch tube in each phase of the three-phase inverter of the wind turbine to be disconnected and the second switch tube to be intermittently closed to perform braking when the headwind speed is greater than or equal to a preset speed.

[0109] For example, a three-phase inverter such as Figure 3 The three-phase full-bridge circuit shown here includes two switches per phase. It should be noted that this hardware structure represents the existing fan drive structure (i.e., the circuit used after startup). The improvement presented in this application is to use this circuit to brake the fan before startup. Furthermore, the first switch referred to in this application can be any switch in each phase.

[0110] In one embodiment, when the headwind speed is less than a preset speed, the first switching tube in each phase of the three-phase inverter of the wind turbine is controlled to be off and the second switching tube is closed until the headwind speed reaches 0. When the headwind speed is less than the preset speed, the headwind speed is relatively low, and braking can be initiated directly without intermittent braking. Therefore, even if braking is continued, heat generation is minimal and winding burnout is unlikely.

[0111] Of course, to ensure safety, in another embodiment, when the headwind speed is less than the preset speed, intermittent braking can still be performed, that is, the first switch tube in each phase of the three-phase inverter of the wind turbine is controlled to be disconnected and the second switch tube is intermittently closed to perform braking.

[0112] It should be noted that when continuous braking is used when the headwind speed is less than a preset speed and intermittent braking is used when the headwind speed is greater than or equal to the preset speed, if intermittent braking is used, the intermittent braking control method can be used until the headwind speed reaches 0. That is, when the headwind speed is greater than or equal to the preset speed, the first switching tube in each phase of the three-phase inverter of the wind turbine is controlled to be disconnected and the second switching tube is intermittently closed until the headwind speed reaches 0.

[0113] Alternatively, the current headwind speed is re-detected after each intermittent braking cycle or a preset number of cycles, and then the control scheme is determined based on the current headwind speed. Therefore, after intermittent braking, the headwind speed will decrease, and then there may be a situation where the headwind speed changes from being greater than or equal to the preset speed to being less than the preset speed. In this case, the continuous braking scheme can be directly adopted. That is:

[0114] When the headwind speed is greater than or equal to the preset speed, the first switch tube in each phase of the three-phase inverter of the fan is controlled to be disconnected and the second switch tube is intermittently closed until the headwind speed is less than the preset speed; when the real-time headwind speed is less than the preset speed, the first switch tube in each phase of the three-phase inverter of the fan is controlled to be disconnected and the second switch tube is closed until the headwind speed is 0.

[0115] As a preferred implementation of the present application, controlling the second switch tube to be intermittently closed includes:

[0116] After each time the second switch tube is controlled to be closed for a first preset time, the second switch tube is controlled to be opened for a second preset time;

[0117] After the second switch tube is controlled to be off for the second preset time period, the second switch tube is controlled to be on for the first preset time period until the headwind speed is 0.

[0118] In one embodiment, the first preset duration and the second preset duration of each cycle are the same;

[0119] Among them, one cycle is that the second switch tube is closed for a first preset time and then opened for a second preset time; the greater the headwind speed, the shorter the first preset time; and / or, the greater the headwind speed, the longer the second preset time.

[0120] Because the higher the headwind speed, the greater the current after the second switch is closed. To avoid burning the winding, the closing time needs to be shorter, that is, the shorter the first preset time. Similarly, for the same closing time, the heat generation is higher, so the longer the opening time for heat dissipation is required, that is, the longer the second preset time is.

[0121] However, in practice, as the second switch is continuously closed, the headwind speed will gradually decrease. If the first preset duration of each closing is the same, the overall control time before startup will be too long. Therefore, in another embodiment, the first preset duration of the current cycle is greater than the first preset duration of the previous cycle, and / or the second preset duration of the current cycle is less than the second preset duration of the previous cycle;

[0122] One cycle is when the second switch is closed for a first preset time and then opened for a second preset time.

[0123] That is, as the headwind speed decreases, the current decreases. The first preset duration can be gradually increased to increase the braking time and quickly reduce the fan speed. As the current decreases, the heat generation also decreases accordingly. Therefore, the second preset duration can be gradually decreased. This ensures the reliability of the fan while speeding up the braking process and reducing the braking time, facilitating a quick start of the fan.

[0124] The fan control device provided in the embodiment of the present application obtains the fan status before the fan is started; obtains the fan's headwind speed when the fan is in the headwind state; and controls the first switch tube in each phase of the three-phase inverter of the fan to be disconnected and the second switch tube to be intermittently closed when the headwind speed is greater than or equal to the preset speed to perform braking. That is, before the fan is started, the present application solution first determines whether the fan is in the headwind state. When it is in the headwind state, the fan inverter is controlled according to the headwind speed to brake the fan. It ensures that the fan is not in the headwind state before starting, avoids the problem of loss of step or overcurrent protection during startup, and ensures that the fan starts successfully. And when the headwind speed is large, the second switch tube is controlled to be intermittently closed to ensure that during the braking process, the current is not too large, causing the winding to be damaged due to overheating.

[0125] Based on the same inventive concept, Figure 6 As shown, the present application also provides a wind turbine control system 60, including:

[0126] at least one processor 61 and at least one memory 62;

[0127] The memory stores executable instructions of the processor;

[0128] The processor is configured to execute the wind turbine control method provided in the above embodiment.

[0129] The fan control system provided by the embodiment of the present application stores executable instructions of the processor in the memory. When the executable instructions are executed, the processor can obtain the fan status before the fan starts; when the fan is in the headwind state, obtain the headwind speed of the fan; when the headwind speed is greater than or equal to the preset speed, control the first switch tube in each phase of the three-phase inverter of the fan to be disconnected and the second switch tube to be intermittently closed to perform braking. That is, before the fan starts, the present application solution first determines whether the fan is in the headwind state. When it is in the headwind state, it controls the fan inverter according to the headwind speed to brake the fan. It ensures that the fan is not in the headwind state before starting, avoids the problem of loss of step or overcurrent protection during startup, and ensures the successful startup of the fan.

[0130] Based on the same inventive concept, the present application also provides a wind turbine, which applies the wind turbine control method provided in the above embodiment.

[0131] The fan provided in the embodiment of the present application, by applying the fan control method provided in the above embodiment, can obtain the fan status before the fan is started; obtain the fan's headwind speed when the fan is in the headwind state; and control the first switch tube in each phase of the three-phase inverter of the fan to be disconnected and the second switch tube to be intermittently closed when the headwind speed is greater than or equal to the preset speed to perform braking. That is, before the fan is started, the present application scheme first determines whether the fan is in the headwind state. When it is in the headwind state, the fan inverter is controlled according to the headwind speed to brake the fan. It ensures that the fan is not in the headwind state before starting, avoids the problem of loss of step or overcurrent protection during startup, and ensures the successful startup of the fan. And when the headwind speed is large, the second switch tube is controlled to be intermittently closed to ensure that during the braking process, the current is not too large, causing the winding to be damaged due to overheating.

[0132] Based on the same inventive concept, the present application also provides an electrical device, including the fan provided in the above embodiment.

[0133] Exemplarily, the electrical device is an air conditioner.

[0134] The electrical equipment provided in the embodiment of the present application includes the fan provided in the above embodiment. By applying the fan control method provided in the above embodiment, the fan can obtain the fan status before the fan is started; when the fan is in the headwind state, obtain the headwind speed of the fan; when the headwind speed is greater than or equal to the preset speed, control the first switch tube in each phase of the three-phase inverter of the fan to be disconnected and the second switch tube to be intermittently closed to perform braking. That is, before the fan is started, the present application scheme first determines whether the fan is in the headwind state. When it is in the headwind state, the fan inverter is controlled according to the headwind speed to brake the fan. It ensures that the fan is not in the headwind state before starting, avoids the problem of loss of step or overcurrent protection during startup, and ensures that the fan starts successfully. And when the headwind speed is large, the second switch tube is controlled to be intermittently closed to ensure that the current is not too large during the braking process, causing the winding to be damaged due to overheating.

[0135] It should be noted that, in the description of this application, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance. In addition, in the description of this application, unless otherwise specified, the meaning of "plurality" refers to at least two.

[0136] It can be understood that the same or similar parts of the above embodiments can be referenced to each other, and the contents not described in detail in some embodiments can refer to the same or similar contents in other embodiments.

Claims

1. A fan control method, characterized in that: include: Before the fan is started, obtaining the fan status; When the fan is in a headwind state, obtaining the headwind rotation speed of the fan; When the headwind speed is greater than or equal to a preset speed, the first switch tube in each phase of the three-phase inverter of the wind turbine is controlled to be disconnected and the second switch tube is intermittently closed to perform braking.

2. The method according to claim 1, wherein: Controlling the intermittent closing of the second switch tube includes: After each time the second switch tube is controlled to be closed for a first preset time, the second switch tube is controlled to be opened for a second preset time; After the second switch tube is controlled to be off for the second preset time period, the second switch tube is controlled to be on for the first preset time period until the headwind speed is 0.

3. The method according to claim 2, characterized in that Also includes: The first preset duration and the second preset duration are the same in each cycle; Among them, one cycle is that the second switch tube is closed for a first preset time and then opened for a second preset time; the greater the headwind speed, the shorter the first preset time; and / or, the greater the headwind speed, the longer the second preset time.

4. The method according to claim 2, characterized in that Also includes: The first preset duration of the current cycle is greater than the first preset duration of the previous cycle, and / or the second preset duration of the current cycle is less than the second preset duration of the previous cycle; One cycle is when the second switch is closed for a first preset time and then opened for a second preset time.

5. The method according to claim 1, wherein Also includes: When the headwind speed is less than a preset speed, the first switch tube in each phase of the three-phase inverter of the wind turbine is controlled to be disconnected and the second switch tube is closed until the headwind speed is 0.

6. The method according to claim 1, wherein: The obtaining of the fan status includes: Obtaining a back electromotive force voltage of the fan; If the back electromotive force voltage is not 0, it is determined that the fan is in a headwind state.

7. The method according to claim 1, wherein: The obtaining of the headwind speed of the fan includes: Obtaining a back electromotive force voltage of the fan; Calculating a back electromotive force frequency based on the back electromotive force voltage, wherein the back electromotive force voltage is proportional to the back electromotive force frequency; The upwind rotation speed of the fan is determined based on the back electromotive force frequency, and the upwind rotation speed is inversely proportional to the back electromotive force frequency.

8. A fan control device, characterized in that: include: A fan status acquisition module is used to acquire the fan status before the fan is started; A headwind speed acquisition module, configured to acquire the headwind speed of the fan when the fan is in a headwind state; The switch tube control module is used to control the first switch tube in each phase of the three-phase inverter of the wind turbine to be disconnected and the second switch tube to be intermittently closed when the headwind speed is greater than or equal to the preset speed, so as to perform braking.

9. A fan control system, characterized in that: include: at least one processor and at least one memory; The memory stores executable instructions of the processor; The processor is configured to execute the method according to any one of claims 1 to 7.

10. A fan, characterized in that: The method according to any one of claims 1 to 7 is used.

11. An electrical device, characterized in that: Including the fan according to claim 10.

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