A tower bottom cooling system and method based on a wind turbine generator

Abstract

This application provides a tower-bottom cooling system and method for wind turbine generators. The system includes a temperature sensor, a temperature controller, a frequency converter, and an axial flow fan. The temperature controller is connected to both the temperature sensor and the frequency converter, which is connected to the axial flow fan. The temperature controller acquires the tower bottom temperature monitored and transmitted by the temperature sensor. When it detects that the tower bottom temperature has reached a preset start-up temperature, it continuously sends a start-up signal to the frequency converter. Upon receiving the start-up signal, the frequency converter controls the axial flow fan to start operating by converting the power frequency supplied to it, thereby cooling the tower bottom of the wind turbine generator. This solves the problem in existing tower-bottom cooling systems where excessive starting current can easily damage the axial flow fan.

Description

Technical Field

[0001] This application relates to the field of wind power generation technology, and in particular to a tower bottom cooling system and method based on a wind turbine generator set. Background Technology

[0002] Wind energy, as a clean and renewable energy source, is receiving increasing attention from countries around the world. Wind turbines can convert wind energy into electrical energy. During hot summer weather, wind turbines absorb a large amount of heat load from the environment. In addition, the operation of large heat-generating components at the base of the wind turbine tower (converter cabinet, main control cabinet, etc.) continuously releases a large amount of heat load, causing the tower base temperature to rise. When the tower base temperature exceeds a preset threshold, the wind turbine may experience an over-temperature fault shutdown, seriously affecting the normal operation and power generation efficiency of the wind turbine.

[0003] In the prior art, during the cooling process of the bottom of the wind turbine tower, the programmable logic controller (PLC) in the tower bottom cooling system can obtain the tower bottom temperature sent by the temperature sensor and directly control the start and stop of the wind turbine based on the tower bottom temperature.

[0004] However, in the existing technology, the PLC directly controls the start and stop of the fan based on the temperature at the bottom of the tower, which has the problem of excessive starting current, which can easily lead to damage to the axial flow fan. Summary of the Invention

[0005] This application provides a tower bottom cooling system and method based on a wind turbine generator set, which solves the problem that the tower bottom cooling system in the prior art has excessive starting current, which can easily lead to damage to the axial flow fan.

[0006] In a first aspect, embodiments of this application provide a tower bottom cooling system based on a wind turbine generator set, comprising: a temperature sensor, a temperature controller, a frequency converter, and an axial flow fan; wherein, the temperature controller is connected to the temperature sensor and the frequency converter, and the frequency converter is connected to the axial flow fan;

[0007] The temperature controller is used to acquire the bottom temperature of the tower monitored and sent by the temperature sensor, and continuously send a start signal to the frequency converter when it is detected that the bottom temperature of the tower has reached the preset start temperature.

[0008] The frequency converter is used to control the axial flow fan to start and run when it receives the start signal by converting the power frequency supplied to the axial flow fan, so as to cool the bottom of the wind turbine tower.

[0009] In one implementation, the temperature controller is specifically used for:

[0010] The timing begins when the temperature at the bottom of the tower is detected to have reached the preset start-up temperature;

[0011] When the temperature at the bottom of the tower reaches the preset start-up temperature within a first preset time period, the start-up signal is continuously sent to the frequency converter.

[0012] In one implementation, the temperature controller is specifically used for:

[0013] The number of startups is obtained, and the preset startup temperature and the first preset duration are adjusted according to the number of startups to obtain the adjusted preset startup temperature and the adjusted first preset duration.

[0014] When the temperature at the bottom of the tower is detected to have reached the adjusted preset start-up temperature, the timing begins;

[0015] When the tower bottom temperature is monitored to reach the adjusted preset start-up temperature within the first preset time period, the start-up signal is continuously sent to the frequency converter, and the start-up count is incremented by 1.

[0016] In one implementation,

[0017] The temperature controller is also used to stop sending the start signal to the frequency converter when it detects that the temperature at the bottom of the tower has reached the preset stop temperature, so that the frequency converter stops controlling the axial flow fan to start and run.

[0018] In one implementation, the temperature controller is specifically used for:

[0019] Timing begins when the temperature at the bottom of the tower is detected to have reached the preset stop temperature;

[0020] When the temperature at the bottom of the tower reaches the preset stop temperature within a second preset time period, the start signal sent to the frequency converter is stopped, so that the frequency converter stops controlling the axial flow fan to start and run.

[0021] Secondly, this application provides a method for cooling the bottom of a wind turbine generator tower, applied to a wind turbine generator tower cooling system. The wind turbine generator tower cooling system includes a temperature sensor, a temperature controller, a frequency converter, and an axial flow fan. The temperature controller is connected to the temperature sensor and the frequency converter, and the frequency converter is connected to the axial flow fan.

[0022] The method includes:

[0023] The temperature controller acquires the tower bottom temperature monitored and sent by the temperature sensor, and continuously sends a start signal to the frequency converter when it detects that the tower bottom temperature has reached the preset start temperature.

[0024] When the frequency converter receives the start signal, it controls the axial flow fan to start and run by changing the power frequency supplied to the axial flow fan, so as to cool the bottom of the wind turbine tower.

[0025] In one implementation, the temperature controller acquires the tower bottom temperature value monitored and sent by the temperature sensor, and when it detects that the tower bottom temperature has reached a preset start-up temperature, it continuously sends a start-up signal to the frequency converter, including:

[0026] The temperature controller starts timing when it detects that the temperature at the bottom of the tower has reached the preset start-up temperature;

[0027] When the temperature controller detects that the temperature at the bottom of the tower has reached the preset start-up temperature within a first preset time period, it continuously sends the start-up signal to the frequency converter.

[0028] In one implementation, the temperature controller starts timing when it detects that the temperature at the bottom of the tower has reached the preset start-up temperature, including:

[0029] The thermostat acquires the number of starts and adjusts the preset start temperature and the first preset duration based on the number of starts to obtain the adjusted preset start temperature and the adjusted first preset duration.

[0030] The temperature controller starts timing when it detects that the temperature at the bottom of the tower has reached the adjusted preset start-up temperature;

[0031] When the temperature controller detects that the temperature at the bottom of the tower has reached the preset start-up temperature within a first preset time period, it continuously sends the start-up signal to the frequency converter, including:

[0032] When the temperature controller detects that the temperature at the bottom of the tower has reached the adjusted preset start-up temperature within the first preset time period, it continuously sends the start-up signal to the frequency converter and increments the start-up count by 1.

[0033] In one implementation, the method further includes:

[0034] When the temperature controller detects that the temperature at the bottom of the tower has reached the preset stop temperature, it stops sending the start signal to the frequency converter, so that the frequency converter stops controlling the axial flow fan to start and run.

[0035] In one implementation, when the temperature controller detects that the temperature at the bottom of the tower has reached a preset stop temperature, it stops sending the start signal to the frequency converter, thereby causing the frequency converter to stop controlling the axial flow fan to start and run, including:

[0036] The temperature controller starts timing when it detects that the temperature at the bottom of the tower has reached the preset stop temperature;

[0037] When the temperature controller detects that the temperature at the bottom of the tower has reached the preset stop temperature within a second preset time period, it stops sending the start signal to the frequency converter, so that the frequency converter stops controlling the axial flow fan to start and run.

[0038] This application provides a tower cooling system and method based on a wind turbine generator. The tower cooling system includes a temperature sensor, a temperature controller, a frequency converter, and an axial flow fan. The temperature controller is connected to both the temperature sensor and the frequency converter, and the frequency converter is connected to the axial flow fan. The temperature controller acquires the tower bottom temperature monitored and transmitted by the temperature sensor, and when it detects that the tower bottom temperature has reached a preset start-up temperature, it continuously sends a start-up signal to the frequency converter. Upon receiving the start-up signal, the frequency converter controls the axial flow fan to start operating by converting the power frequency supplied to the axial flow fan, thereby cooling the tower bottom of the wind turbine generator. Compared to existing technologies where a PLC directly controls the start and stop of the fan based on the bottom temperature of the tower, which carries the risk of excessive starting current and damage to the axial fan, this embodiment utilizes a frequency converter to change the power frequency supplied to the axial fan. This allows the starting current of the axial fan to increase smoothly from zero, achieving soft start-up and avoiding the situation where directly inputting the rated power frequency to the axial fan would cause a surge in starting current and damage. Furthermore, this embodiment eliminates the need for a PLC, instead employing a low-cost and high-precision temperature controller to control the bottom temperature of the tower, thus solving the problems of high cost and low cooling efficiency in existing tower bottom cooling systems. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 A schematic diagram of a tower bottom cooling system based on a wind turbine generator set is provided for an embodiment of this application;

[0041] Figure 2This is a schematic diagram of the structure of the tower base of a wind turbine generator provided in an embodiment of this application;

[0042] Figure 3 A schematic flowchart of an embodiment of a method for cooling the bottom of a wind turbine generator set, provided in this application.

[0043] Figure 4 A schematic flowchart of a second embodiment of a tower bottom cooling method for wind turbine generators provided in this application;

[0044] Figure 5 A schematic flowchart of a third embodiment of a tower bottom cooling method for wind turbine generators provided in this application;

[0045] Figure 6 This is a schematic flowchart of a fourth embodiment of a tower cooling method for wind turbine generators provided in this application. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments made by those skilled in the art under the guidance of these embodiments are within the scope of protection of this application.

[0047] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0048] In existing technologies, during the cooling process of the wind turbine tower base, the programmable logic controller (PLC) in the tower base cooling system can acquire the tower base temperature sent by the temperature sensor and directly control the start and stop of the wind turbine based on the tower base temperature. However, in existing technologies, the PLC directly controls the start and stop of the wind turbine based on the tower base temperature, which has the problem of excessive starting current and can easily lead to damage to the axial flow fan.

[0049] Based on the above-mentioned technical problems, the technical concept of this application embodiment is as follows: When the temperature controller detects that the temperature at the bottom of the tower has reached the preset start-up temperature, it continuously sends a start-up signal to the frequency converter, so that when the frequency converter receives the start-up signal, it controls the start-up current of the axial flow fan by converting the power frequency supplied to the axial flow fan, thereby controlling the start-up and operation of the axial flow fan, and thus realizing the soft start of the axial flow fan.

[0050] The principles and features of embodiments of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the embodiments of the present invention and are not intended to limit the scope of the embodiments of the present invention. It should be noted that the following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0051] Figure 1 This is a schematic diagram of a tower bottom cooling system based on a wind turbine generator set, provided as an embodiment of this application. Figure 1 As shown, the tower bottom cooling system 10 based on the wind turbine generator includes: a temperature sensor 101, a temperature controller 102, a frequency converter 103, and an axial flow fan 104.

[0052] The temperature controller 102 is connected to the temperature sensor 101 and the frequency converter 103, and the frequency converter 103 is connected to the axial flow fan 104.

[0053] Additionally, the tower cooling system 10 based on the wind turbine generator may also include a power supply 105. The power supply 105 is connected to both the temperature controller 102 and the frequency converter 103. In one implementation, the power supply 105 can be the AC cabinet of the wind turbine generator. In another implementation, the temperature sensor 101 can be a platinum resistance thermometer PT100, and the frequency converter 103 can be an ABB frequency converter.

[0054] In this embodiment, the temperature sensor 101 can be installed at the bottom of the tower to monitor the temperature at the bottom of the wind turbine tower. The temperature sensor 101 can send the temperature at the bottom of the tower to the temperature controller 102.

[0055] After receiving the bottom temperature of the tower from the temperature sensor 101, the temperature controller 102 can identify whether the bottom temperature of the tower has reached the preset start-up temperature. For example, the preset start-up temperature can be 30°C.

[0056] When the temperature controller 102 detects that the temperature at the bottom of the tower has reached the preset start-up temperature, it continuously sends a start-up signal to the frequency converter 103. Specifically, when the temperature controller 102 detects that the temperature at the bottom of the tower has reached the preset start-up temperature, its internal auxiliary contacts are closed. With the internal contacts of the temperature controller 102 closed, the temperature controller 102 can continuously send start-up signals to the frequency converter 103.

[0057] When the frequency converter 103 receives the start signal, it can change the speed of the axial fan 104 by converting the power frequency input to the axial fan 104, thereby controlling the axial fan 104 to start and run, and thus cooling the bottom of the wind turbine tower.

[0058] Specifically, the rotational speed of the axial flow fan 104 is related to the power supply frequency as follows:

[0059]

[0060] Where f is the power supply frequency, n is the rotational speed, s is the slip, and P is the number of stator winding pole pairs. Based on the above formula, it can be seen that the rotational speed of the axial flow fan 104 changes accordingly when the power supply frequency changes.

[0061] When the inverter 103 receives the start signal, it can increase the output frequency in a linear torque characteristic curve according to the preset U / F curve (the preset ratio curve of inverter output voltage and inverter output frequency). In other words, it can change the power frequency supplied to the axial flow fan 104 so that the power frequency of the axial flow fan 104 increases smoothly from zero.

[0062] When the power supply frequency of the axial flow fan 104 reaches the starting power supply frequency, that is, when the current of the axial flow fan 104 reaches the starting current, the axial flow fan 104 starts to operate. When the power supply frequency of the axial flow fan 104 reaches the maximum power supply frequency, the rotational speed of the axial flow fan 104 reaches the rated speed and operates at a constant rated speed. For example, the maximum power supply frequency can be 50 Hz, and the starting power supply frequency can be 25 Hz.

[0063] Figure 2 This is a schematic diagram of the structure of the tower base of a wind turbine generator provided in an embodiment of this application, as shown below. Figure 2As shown, when the axial fan 104 starts running, it allows high-heat-load gas to be discharged from the bottom of the wind turbine tower, thus cooling the tower. In one implementation, an AC cabinet (power supply 105) can be placed at the bottom of the wind turbine tower. The temperature controller 102 and frequency converter 103 can be integrated into a housing 106, while the temperature sensor 101 is placed outside the housing 106. The housing 106 is then fixed to the tower base platform at the bottom of the wind turbine tower. It should be noted that... Figure 2 Only the enclosure 106 is shown; the temperature controller 102 and frequency converter 103 inside the enclosure are not shown, nor is the temperature sensor 101 outside the enclosure.

[0064] In this embodiment, the tower-bottom cooling system for wind turbine generators includes a temperature sensor, a temperature controller, a frequency converter, and an axial flow fan. The temperature controller is connected to both the temperature sensor and the frequency converter, and the frequency converter is connected to the axial flow fan. The temperature controller acquires the tower-bottom temperature monitored and transmitted by the temperature sensor, and continuously sends a start signal to the frequency converter when it detects that the tower-bottom temperature has reached the preset start-up temperature. Upon receiving the start signal, the frequency converter controls the axial flow fan to start and run by converting the power frequency supplied to the axial flow fan, thereby cooling the tower bottom of the wind turbine generator. Compared to the prior art where the PLC directly controls the fan's start and stop based on the tower-bottom temperature, which may result in excessive starting current and damage to the axial flow fan, in this embodiment, the temperature controller can use the frequency converter to convert the power frequency supplied to the axial flow fan, allowing the starting current of the axial flow fan to increase smoothly from zero. This achieves soft start of the axial flow fan, avoiding the situation where directly inputting the rated power frequency to the axial flow fan would cause the starting current to surge and damage the axial flow fan. In addition, the embodiments of this application do not require the use of a PLC, but instead use a low-cost and high-precision temperature controller to control the temperature at the bottom of the tower, thus solving the problems of high cost and low cooling efficiency in the existing tower bottom cooling system.

[0065] The process of the temperature controller 102 delaying the sending of the start signal to the frequency converter 103 will be described below through Example 2.

[0066] In this embodiment, the temperature controller 102 can acquire the bottom temperature of the tower monitored and sent by the temperature sensor 101.

[0067] When the temperature controller 102 detects that the temperature at the bottom of the tower has reached the preset start-up temperature, it starts timing. If the temperature controller 102 detects that the temperature at the bottom of the tower has reached the preset start-up temperature for a first preset time period, it determines that the current temperature is not an occasional high temperature value, nor is it a high temperature value caused by a detection error by the temperature sensor 101, and therefore cooling treatment of the bottom of the tower is required. For example, the first preset time period can be 10 minutes.

[0068] The temperature controller 102 can continuously send a start signal to the frequency converter 103. When the frequency converter 103 receives the start signal, it converts the power frequency supplied to the axial flow fan 104 according to a preset curve, so that the power frequency of the axial flow fan 104 increases smoothly from zero, thereby controlling the axial flow fan 104 to start and run, so as to cool the bottom of the wind turbine tower.

[0069] In this embodiment, the temperature controller can continuously send a start signal to the frequency converter when it detects that the temperature at the bottom of the tower has reached the preset start temperature within a first preset time period, so that the frequency converter can control the axial flow fan to start softly. By delaying the sending of the start signal as described above, it is possible to avoid the temperature controller sending a start signal to the frequency converter when the temperature at the bottom of the tower is an intermittent high value, or when the temperature sensor detects a high value due to an error, which would result in the axial flow fan starting to run when the actual temperature at the bottom of the tower is low, thus leading to energy loss.

[0070] The process of adjusting the preset start-up temperature and / or the first preset duration based on the number of start-ups is described below through Example 3.

[0071] In one implementation, the thermostat 102 can adjust the preset start-up temperature and the first preset duration based on the number of starts.

[0072] Specifically, the temperature controller 102 can acquire the bottom temperature of the tower monitored and sent by the temperature sensor 101.

[0073] The temperature controller 102 can acquire the number of starts and adjust the preset start temperature and the first preset duration based on the number of starts to obtain the adjusted preset start temperature and the adjusted first preset duration. When the temperature controller 102 detects that the tower bottom temperature has reached the adjusted preset start temperature, it starts timing. If the tower bottom temperature remains at the adjusted preset start temperature for the entire first preset duration, it continuously sends a start signal to the frequency converter 103 and increments the start count by 1. Upon receiving the start signal, the frequency converter 103 controls the axial flow fan 104 by converting the power frequency supplied to it, smoothly increasing the power frequency from zero, thereby controlling the axial flow fan 104 to start operation and cool the bottom of the wind turbine tower. For example, the preset start temperature corresponding to a start count of 1-10 can be 30°C, and the corresponding first preset duration is 10 minutes; the preset start temperature corresponding to a start count of 11-20 can be 29°C, and the corresponding first preset duration is 6 minutes.

[0074] In one implementation, the thermostat 102 can adjust the preset start-up temperature based on the number of starts.

[0075] Specifically, the temperature controller 102 can acquire the tower bottom temperature monitored and sent by the temperature sensor 101. The temperature controller 102 can acquire the number of starts and adjust the preset start temperature according to the number of starts to obtain the adjusted preset start temperature. When the temperature controller 102 detects that the tower bottom temperature has reached the adjusted preset start temperature, it starts timing, and when the tower bottom temperature has reached the adjusted preset start temperature for a first preset time period, it continuously sends a start signal to the frequency converter 103 and increments the start count by 1. When the frequency converter 103 receives the start signal, it controls the power frequency of the axial flow fan 104 to increase smoothly from zero by converting the power frequency supplied to the axial flow fan 104, thereby controlling the axial flow fan 104 to start operation and cool the tower bottom of the wind turbine generator.

[0076] In one implementation, the thermostat 102 can adjust the first preset duration based on the number of times it is started.

[0077] In one implementation, the temperature controller 102 can acquire the tower bottom temperature monitored and transmitted by the temperature sensor 101. The temperature controller 102 can acquire the number of starts and adjust a first preset duration based on the number of starts to obtain an adjusted first preset duration. When the temperature controller 102 detects that the tower bottom temperature has reached the preset start temperature, it starts timing. If the tower bottom temperature remains at the preset start temperature for the adjusted first preset duration, it continuously sends a start signal to the frequency converter 103 and increments the start count by 1. Upon receiving the start signal, the frequency converter 103 controls the axial flow fan 104 to smoothly increase its power frequency from zero by converting the power frequency supplied to the axial flow fan 104, thereby controlling the axial flow fan 104 to start operation and cool the tower bottom of the wind turbine generator.

[0078] In this embodiment, the temperature controller can increment the start count by 1 when sending a start signal to the frequency converter to control the axial flow fan to start. The temperature controller can record the number of axial flow fan starts and adjust the preset start temperature and / or the first preset duration based on the number of starts, so that the adjusted preset start temperature and / or the first preset duration match the number of axial flow fan starts, that is, match the actual control of the tower bottom temperature. In this way, it can ensure that when the tower bottom temperature is frequently high, i.e., when the axial flow fan is frequently controlled to start, the temperature controller can change the conditions for controlling the axial flow fan to start and extend the duration of the axial flow fan operation, thereby reducing the number of times the axial flow fan is controlled to start. This avoids frequent start-stop of the axial flow fan, and thus improves the service life of the axial flow fan while providing timely cooling to the tower bottom.

[0079] The following describes, through Example 4, the process of temperature controller 102 controlling the axial flow fan 104 to stop and start operation.

[0080] In this embodiment, the temperature controller 102 can acquire the tower bottom temperature monitored and sent by the temperature sensor 101, and continuously send a start signal to the frequency converter 103 when it detects that the tower bottom temperature has reached the preset start temperature. When the frequency converter 103 receives the start signal, it controls the axial flow fan to start running by converting the power frequency supplied to the axial flow fan 104.

[0081] When the temperature controller 102 detects that the temperature at the bottom of the tower has reached the preset stop temperature, it stops sending the start signal to the frequency converter 103, so that the frequency converter 103 stops controlling the start-up operation of the axial flow fan 104. For example, the preset stop temperature can be 28°C, and the preset stop temperature can also be 26°C.

[0082] Specifically, when the temperature controller 102 detects that the temperature at the bottom of the tower has reached the preset stop temperature, the auxiliary contact inside the temperature controller 102 disconnects, and the temperature controller 102 stops sending start signals to the frequency converter 103. With the temperature controller 102 ceasing to send start signals to the frequency converter 103, the frequency converter 103 can convert the power frequency supplied to the axial flow fan 104 according to a preset U / F curve, so that the power frequency of the axial flow fan 104 gradually decreases, thereby controlling the speed of the axial flow fan 104 to gradually decrease to zero.

[0083] In one implementation, the temperature controller 102 starts timing when it detects that the temperature at the bottom of the tower has reached a preset stop temperature. When the temperature controller 102 detects that the temperature at the bottom of the tower has reached the preset stop temperature for a second preset time period, it stops sending a start signal to the frequency converter 103, causing the frequency converter 103 to stop controlling the axial flow fan 104 to start operating. For example, the second preset time period can be 5 minutes.

[0084] In this embodiment, the temperature controller continuously sends start signals to the frequency converter. When it detects that the temperature at the bottom of the tower has reached the preset stop temperature, it stops sending start signals to the frequency converter, causing the frequency converter to stop controlling the axial flow fan. This method achieves a soft stop for the axial flow fan, preventing damage caused by sudden shutdown. Furthermore, this method ensures efficient cooling at the bottom of the tower, guaranteeing the normal operation of the wind turbine generator, while preventing prolonged operation of the axial flow fan, thus saving energy.

[0085] Figure 3 A schematic flowchart of an embodiment of a tower cooling method for wind turbine generators provided in this application is shown below. Figure 3 The method specifically includes the following steps:

[0086] S301: The temperature controller acquires the tower bottom temperature monitored and sent by the temperature sensor, and continuously sends a start signal to the frequency converter when it detects that the tower bottom temperature has reached the preset start temperature.

[0087] S302: When the frequency converter receives the start signal, it controls the axial flow fan to start and run by changing the power frequency supplied to the axial flow fan in order to cool the bottom of the wind turbine tower.

[0088] In this embodiment, the temperature controller can acquire the tower bottom temperature monitored and sent by the temperature sensor, and continuously send a start signal to the frequency converter when it detects that the tower bottom temperature has reached the preset start temperature. Upon receiving the start signal, the frequency converter controls the axial flow fan to start and run by converting the power frequency supplied to the axial flow fan, thereby cooling the tower bottom of the wind turbine. Compared to the prior art where the PLC directly controls the fan's start and stop based on the tower bottom temperature, which may result in excessive starting current and damage to the axial flow fan, in this embodiment, the temperature controller can use the frequency converter to convert the power frequency supplied to the axial flow fan to achieve soft start-up of the axial flow fan. This avoids the situation where directly inputting the rated power frequency to the axial flow fan would cause a starting current surge that could damage the axial flow fan. Furthermore, this embodiment does not require a PLC; instead, it uses a low-cost and high-precision temperature controller to control the tower bottom temperature, solving the problems of high cost and low cooling efficiency in existing tower bottom cooling systems.

[0089] Figure 4 A schematic flowchart of a second embodiment of a tower bottom cooling method for wind turbine generators provided in this application is shown below. Figure 4 The method specifically includes the following steps:

[0090] S401: The temperature controller acquires the bottom temperature of the tower monitored and sent by the temperature sensor.

[0091] S402: The temperature controller starts timing when it detects that the temperature at the bottom of the tower has reached the preset start-up temperature.

[0092] S403: When the temperature controller detects that the temperature at the bottom of the tower has reached the preset start temperature within a first preset time period, it continuously sends a start signal to the frequency converter.

[0093] S404: When the frequency converter receives the start signal, it controls the axial flow fan to start and run by changing the power frequency supplied to the axial flow fan in order to cool the bottom of the wind turbine tower.

[0094] In this embodiment, the temperature controller can continuously send a start signal to the frequency converter when it detects that the temperature at the bottom of the tower has reached the preset start temperature within a first preset time period, so that the frequency converter can control the axial flow fan to start softly. By delaying the sending of the start signal as described above, it is possible to avoid the temperature controller sending a start signal to the frequency converter when the temperature at the bottom of the tower is an intermittent high value, or when the temperature sensor detects a high value due to an error, which would result in the axial flow fan starting to run when the actual temperature at the bottom of the tower is low, thus leading to energy loss.

[0095] Figure 5 A schematic flowchart of a third embodiment of a tower cooling method for wind turbine generators provided in this application is shown below. Figure 5 The method specifically includes the following steps:

[0096] S501: The temperature controller acquires the bottom temperature of the tower as monitored and sent by the temperature sensor.

[0097] S502: The thermostat obtains the number of starts and adjusts the preset start temperature and the first preset duration based on the number of starts to obtain the adjusted preset start temperature and the adjusted first preset duration.

[0098] S503: The temperature controller starts timing when it detects that the temperature at the bottom of the tower has reached the adjusted preset start-up temperature.

[0099] S504: When the temperature controller detects that the temperature at the bottom of the tower has reached the adjusted preset start temperature within the first preset time period, it continuously sends a start signal to the frequency converter and increments the start count by 1.

[0100] S505: When the frequency converter receives the start signal, it controls the axial flow fan to start and run by changing the power frequency supplied to the axial flow fan in order to cool the bottom of the wind turbine tower.

[0101] In this embodiment, the temperature controller can increment the start count by 1 when sending a start signal to the frequency converter, that is, when controlling the axial flow fan to start. The temperature controller can record the number of axial flow fan starts and adjust the preset start temperature and / or the first preset duration based on the number of axial flow fan starts, so that the adjusted preset start temperature and / or the first preset duration match the number of axial flow fan starts, that is, match the actual control situation of the tower bottom temperature. This ensures that when the tower bottom temperature is frequently high, that is, when the axial flow fan is frequently controlled to start, the temperature controller can reduce the number of times the axial flow fan is controlled to start by changing the conditions for controlling the axial flow fan to start and delay the duration of the axial flow fan operation. This avoids frequent start-stop of the axial flow fan, thereby improving the service life of the axial flow fan while providing timely cooling to the tower bottom.

[0102] Figure 6 A schematic flowchart of a method for cooling the bottom of a wind turbine tower, provided in this application, is shown in Embodiment 4. Figure 6 The method specifically includes the following steps:

[0103] S601: The temperature controller acquires the tower bottom temperature monitored and sent by the temperature sensor, and continuously sends a start signal to the frequency converter when it detects that the tower bottom temperature has reached the preset start temperature.

[0104] S602: When the frequency converter receives the start signal, it controls the axial flow fan to start and run by changing the power frequency supplied to the axial flow fan in order to cool the bottom of the wind turbine tower.

[0105] S603: When the temperature controller detects that the temperature at the bottom of the tower has reached the preset stop temperature, it stops sending the start signal to the frequency converter, so that the frequency converter stops controlling the axial flow fan to start and run.

[0106] In this embodiment, the temperature controller can stop sending a start signal to the frequency converter when it detects that the temperature at the bottom of the tower has reached the preset stop temperature, so that the frequency converter stops controlling the axial flow fan to start and run.

[0107] In one implementation, the temperature controller starts timing when it detects that the temperature at the bottom of the tower has reached the preset stop temperature, and stops sending start signals to the frequency converter when it detects that the temperature at the bottom of the tower has reached the preset stop temperature within a second preset time period, so that the frequency converter stops controlling the axial flow fan to start and run.

[0108] In this embodiment, the temperature controller continuously sends start signals to the frequency converter. When it detects that the temperature at the bottom of the tower has reached the preset stop temperature, it stops sending start signals to the frequency converter, thereby causing the frequency converter to stop controlling the axial flow fan to start and run. This method ensures the cooling efficiency at the bottom of the tower, guaranteeing the normal operation of the wind turbine generator, while avoiding prolonged operation of the axial flow fan, thus saving energy.

[0109] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A tower base cooling system based on a wind turbine generator unit, characterized in that, include: A temperature sensor, a temperature controller, a frequency converter, and an axial flow fan; wherein the temperature controller is connected to both the temperature sensor and the frequency converter, and the frequency converter is connected to the axial flow fan; The temperature controller is used to acquire the bottom temperature of the tower monitored and sent by the temperature sensor, and continuously send a start signal to the frequency converter when it is detected that the bottom temperature of the tower has reached the preset start temperature. The inverter is used to, upon receiving the start signal, convert the power frequency supplied to the axial flow fan according to a preset ratio curve of inverter output voltage and inverter output frequency, so that the power frequency of the axial flow fan increases smoothly from zero, thereby controlling the axial flow fan to start and run, so as to cool the bottom of the wind turbine tower. The temperature controller is specifically used for: The number of startups is obtained, and the preset startup temperature and the first preset duration are adjusted according to the number of startups to obtain the adjusted preset startup temperature and the adjusted first preset duration. When the temperature at the bottom of the tower is detected to have reached the adjusted preset start-up temperature, the timing begins; When the tower bottom temperature is detected to reach the adjusted preset start-up temperature within the first preset time period, the start-up signal is continuously sent to the frequency converter, and the start-up count is incremented by 1. The temperature controller is also used to start timing when it detects that the temperature at the bottom of the tower has reached the preset stop temperature; When the temperature at the bottom of the tower reaches the preset stop temperature within a second preset time period, the start signal sent to the frequency converter is stopped, so that the frequency converter stops controlling the axial flow fan to start and run.

2. A method for cooling the bottom of a wind turbine generator tower, characterized in that, The cooling system is applied to the tower bottom cooling system based on a wind turbine generator as described in claim 1, wherein the tower bottom cooling system based on a wind turbine generator includes: a temperature sensor, a temperature controller, a frequency converter, and an axial flow fan; wherein the temperature controller is connected to the temperature sensor and the frequency converter, and the frequency converter is connected to the axial flow fan; The method includes: The temperature controller acquires the tower bottom temperature monitored and sent by the temperature sensor, and continuously sends a start signal to the frequency converter when it detects that the tower bottom temperature has reached the preset start temperature. When the inverter receives the start signal, it converts the power frequency supplied to the axial flow fan according to the preset ratio curve of inverter output voltage and inverter output frequency, so that the power frequency of the axial flow fan increases smoothly from zero, and controls the axial flow fan to start and run, so as to cool the bottom of the wind turbine tower. The temperature controller acquires the tower bottom temperature value monitored and sent by the temperature sensor, and when it detects that the tower bottom temperature has reached the preset start-up temperature, it continuously sends a start-up signal to the frequency converter, including: The thermostat acquires the number of starts and adjusts the preset start temperature and the first preset duration based on the number of starts to obtain the adjusted preset start temperature and the adjusted first preset duration. The temperature controller starts timing when it detects that the temperature at the bottom of the tower has reached the adjusted preset start-up temperature; When the temperature controller detects that the temperature at the bottom of the tower has reached the adjusted preset start temperature within the first preset time period, it continuously sends the start signal to the frequency converter and increments the start count by 1. The method further includes: The temperature controller starts timing when it detects that the temperature at the bottom of the tower has reached the preset stop temperature; When the temperature controller detects that the temperature at the bottom of the tower has reached the preset stop temperature within a second preset time period, it stops sending the start signal to the frequency converter, so that the frequency converter stops controlling the axial flow fan to start and run.

Images