Pitch system and its deceleration and braking device

Abstract

This disclosure relates to a pitch control system and its deceleration and braking device, comprising a housing, a braking resistor, and cooling fans. The housing includes two independent receiving cavities, with heat dissipation holes communicating with each cavity on opposite sides of a first direction. Each cavity contains at least one braking resistor, and the braking resistors in the two cavities are connected in parallel. Two sets of cooling fans are included, one set communicating with one cavity and the other with the other cavity. These fans supply air to the cavities, allowing the air entering the cavities to exit through the heat dissipation holes on opposite sides of the housing in the first direction. This dual-cavity heat dissipation structure improves the heat dissipation performance of the deceleration and braking device through physical isolation.

Description

Technical Field

[0001] This disclosure relates to the field of wind power, and more particularly to a pitch system and its deceleration and braking device. Background Technology

[0002] In the wind power sector, the pitch system is the core system of a wind turbine, crucial for the safe and efficient operation of the unit. The pitch system adjusts the pitch angle of the blades, changing the angle of attack of the airflow on the blades, thereby controlling the aerodynamic torque and power captured by the rotor. Within the wind turbine pitch system, the braking resistor plays a key role in absorbing the braking energy of the blades during deceleration.

[0003] In existing technologies, deceleration and braking devices typically employ a centralized layout, where all braking resistors are integrated into a single enclosed cavity. With this layout, the high-temperature airflow generated by the braking resistors during braking is constrained by the internal cavity structure and can only be discharged through one side or localized heat dissipation holes, leading to the formation of a heat recirculation zone within the cavity. The cumulative temperature rise caused by insufficient heat dissipation can shorten the lifespan of the resistor module and even cause insulation failure, threatening the safe operation of the wind turbine. Utility Model Content

[0004] The purpose of this disclosure is to provide a pitch system and its deceleration and braking device to improve the heat dissipation performance of the pitch system's deceleration and braking device.

[0005] To achieve the above objectives, a first aspect of this disclosure provides a deceleration and braking device for a pitch system, comprising a housing, a braking resistor, and cooling fans. The housing includes two independent receiving cavities, with heat dissipation holes communicating with the receiving cavities on opposite sides in a first direction. Each receiving cavity contains at least one braking resistor, and the braking resistors in the two receiving cavities are connected in parallel. Two sets of cooling fans are provided, one set communicating with one receiving cavity and the other set communicating with the other receiving cavity. The cooling fans are used to supply air to the receiving cavities, allowing the air entering the receiving cavities to be discharged through the heat dissipation holes on opposite sides in the first direction of the housing.

[0006] Through the above-described technical solution, namely the deceleration and braking device of the pitch system disclosed herein, two independent receiving chambers each contain parallel braking resistors. When the cooling fan blows air into the receiving chambers, the airflow is directionally discharged through the heat dissipation holes on both sides in the first direction, forming a through-flow air duct. Compared with the traditional single-chamber heat dissipation structure, the dual air duct shortens the airflow path, preventing the accumulation of hot air within the chamber. The parallel connection of the braking resistors ensures uniform heat distribution, preventing localized overheating. The dual-chamber heat dissipation structure improves the heat dissipation performance of the deceleration and braking device through physical isolation.

[0007] In some possible implementations, the two accommodating cavities are arranged along a second direction; in the second direction, the cooling fan corresponding to one of the accommodating cavities is located on the side of the housing away from the other accommodating cavity.

[0008] In some possible implementations, the deceleration braking device further includes a wire-binding bracket disposed on the outer wall of the housing; and / or, the deceleration braking device further includes a handle disposed on the outer wall of the housing; and / or, the deceleration braking device further includes two wiring portions that extend at least partially to the outer side of the housing.

[0009] In some possible implementations, the deceleration braking device further includes a mounting bracket located at the bottom of the housing for mounting the deceleration braking device.

[0010] In some possible implementations, the deceleration braking device further includes at least three sets of temperature sensors, which are used to collect temperature data of the geometric center region, the heat accumulation region, and the heat dissipation airflow outlet region of the braking resistor; the temperature sensors are electrically connected to the cooling fan.

[0011] According to a second aspect of this disclosure, a pitch system is also provided, which integrates the aforementioned deceleration and braking device.

[0012] Through the aforementioned technical solution, namely the second aspect of this disclosure, multiple braking resistors can effectively absorb peak power when the blade pitch generates regenerative energy. When one braking resistor experiences functional degradation or even failure due to overload, aging, or a sudden impact, and the pitch system is unable to discharge energy, another braking resistor can still operate normally. This redundancy design can solve the problem of a rapid rise in DC bus voltage threatening the safe operation of the wind turbine when a single braking resistor fails and the pitch system lacks an energy discharge channel.

[0013] In some possible implementations, the pitch system includes a pitch shaft housing and at least two deceleration braking devices; the two deceleration braking devices are each independently disposed outside the pitch shaft housing and are electrically connected in parallel to the DC bus.

[0014] In some possible implementations, the resistance values ​​of the two deceleration and braking devices are equal.

[0015] In some possible implementations, the two deceleration and braking devices are fixed to different areas of the hub wall in a staggered manner.

[0016] In some possible implementations, the pitch system further includes an alarm device electrically connected to the temperature sensor and / or DC bus of the deceleration braking device.

[0017] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0018] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a perspective view of the internal structure of the deceleration and braking device provided in an exemplary embodiment of this disclosure (with the side panel of the housing removed). Figure 2 This is a perspective view of the deceleration and braking device provided in an exemplary embodiment of this disclosure; Figure 3 This is a front view of the deceleration and braking device provided in an exemplary embodiment of this disclosure; Figure 4 This is a left view of the deceleration and braking device provided in an exemplary embodiment of this disclosure; Figure 5 This is a top view of the deceleration and braking device provided in an exemplary embodiment of this disclosure; Figure 6 This is a schematic diagram of a pitch system provided in an exemplary embodiment of this disclosure; Figure 7 This is a flowchart of the pitch system energy management control provided in an exemplary embodiment of this disclosure.

[0019] Explanation of reference numerals in the attached figures 10-Deceleration and braking device; 100-Box; 110-Receiving cavity; 120-Heat dissipation hole; 200-Brake resistor; 300-Cooling fan; 400-Wire binding bracket; 500-Handle; 600-Wiring part; 700-Mounting bracket; 800-Temperature sensor; 20-Pitch shaft box. Detailed Implementation

[0020] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0021] In this disclosure, unless otherwise stated, directional terms such as "inner" and "outer" refer to the outline of the corresponding component itself, and terms such as "first" and "second" are used to distinguish one element from another and do not have sequential or importance. In this disclosure, for ease of description, an XYZ coordinate system is established for the deceleration and braking device, where the X direction is the first direction, the Y direction is the second direction, the Z direction is the third direction, and the top is one end of the bracket fixed along the Z direction. When the following description relates to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements.

[0022] According to the first aspect of this disclosure, reference to Figures 1 to 5 As shown, the deceleration and braking device 10 of the pitch system includes a housing 100, a braking resistor 200, and a cooling fan 300. The housing 100 includes two independent receiving cavities 110, and heat dissipation holes 120 communicating with the receiving cavities 110 are respectively provided on opposite sides of the housing 100 in a first direction. Each receiving cavity 110 contains at least one braking resistor 200, and the braking resistors 200 in the two receiving cavities 110 are connected in parallel. There are also two sets of cooling fans 300, one set of cooling fans 300 communicating with one receiving cavity 110 and the other set of cooling fans 300 communicating with the other receiving cavity 110. The cooling fans 300 are used to deliver air to the receiving cavities 110, so that the air entering the receiving cavities 110 can be discharged through the heat dissipation holes 120 arranged opposite sides of the housing 100 in the first direction.

[0023] Through the above technical solution, namely the deceleration braking device 10 of the pitch system disclosed herein, two independent receiving cavities 110 each contain a parallel braking resistor 200. When the cooling fan 300 blows air into the receiving cavity 110, the airflow is directionally discharged through the heat dissipation holes 120 on both sides in the first direction, forming a through-flow air duct. Compared with the traditional single-cavity heat dissipation structure, the dual air duct shortens the airflow path and avoids the accumulation of hot air in the housing 100. The parallel connection of the braking resistors 200 ensures uniform heat distribution and prevents local overheating. The dual-cavity heat dissipation structure improves the heat dissipation performance of the deceleration braking device 10 through physical isolation.

[0024] It should be noted that each receiving cavity 110 may contain one braking resistor 200, and the braking resistors 200 in two receiving cavities 110 are connected in parallel. Alternatively, each receiving cavity 110 may contain two or more braking resistors 200, and these two or more braking resistors 200 are connected in parallel. Furthermore, the parallel-connected braking resistors 200 in one receiving cavity 110 are also connected in parallel with the braking resistors 200 in the other receiving cavity 110. This disclosure, by arranging multiple braking resistors 200 separately inside two receiving cavities 110 and using their respective corresponding cooling fans 300 for heat dissipation, reduces the superposition of heat generated by the braking resistors 200, thus improving overall heat dissipation.

[0025] In some embodiments, reference Figure 2 As shown, two receiving cavities 110 are arranged along a second direction, with a cooling fan 300 corresponding to one receiving cavity 110 located on the side of the housing 100 away from the other receiving cavity 110. The two receiving cavities 110 are arranged along the second direction, with the cooling fans 300 positioned on the sides of each receiving cavity 110 away from each other, forming a back-draft mechanism. Cool air drawn in by one set of cooling fans 300 connected to one receiving cavity 110 is discharged through the heat dissipation holes 120 of that receiving cavity 110. Simultaneously, another set of cooling fans 300 connected to the other receiving cavity 110 draws in air in the opposite direction. The two airflows form a centrifugal diffusion rather than a converging and opposing flow, allowing the heat from the braking resistor 200 to be conducted from the center to both sides along the first direction. This arrangement avoids the exhaust of high-temperature gas being drawn in again by adjacent fans, thus improving heat dissipation efficiency.

[0026] In some embodiments, four braking resistors 200 are integrated inside the housing 100 and arranged in an array along the Z direction within the cavity. Each pair of resistors forms a thermal management unit and is equipped with an independent cooling fan 300. When the cooling fan 300 is activated, airflow flows along the X direction from the center of the braking resistors 200 to both ends, directing the heat generated by the braking resistors 200 to both ends of the housing 100 and dissipating it through the heat dissipation holes 120, forming a directional heat dissipation path.

[0027] In some embodiments, reference Figure 2 As shown, the deceleration and braking device 10 also includes a cable tie bracket 400, a handle 500, and two wiring portions 600 that extend at least partially to the outside of the housing 100, all disposed on the outer wall of the housing 100. A portion of the cable tie bracket 400 is located on one side of the housing 100 along a first direction, while the other portion of the cable tie bracket 400, handle 500, and two wiring portions 600 are located on the top of the housing 100. The handle 500 is located at the center of the housing 100 in both the first and second directions. The two wiring portions 600 are adjacent to the cable tie bracket 400 in the second direction, and the positions of the cable tie bracket 400, handle 500, and wiring portions 600 do not overlap.

[0028] It is understood that in some embodiments, the deceleration and braking device 10 further includes a wire-binding bracket 400 disposed on the outer wall of the enclosure 100. Multiple wire-binding brackets 400 may be provided, and they may be disposed on the top or side of the enclosure 100, for fixing high-voltage or low-voltage wire harnesses. The wire-binding bracket 400 provides stable constraint to the wire harness, reducing the vibration amplitude of the wire harness and lowering the risk of insulation wear. The signal line of the temperature sensor 800, the cables of the enclosure 100, and the cables of the cooling fan 300 are managed in a unified wire harness through the wire-binding bracket 400, and connected to the control cabinet to complete the construction of the signal transmission and energy dissipation circuit.

[0029] It is understood that in some embodiments, the deceleration braking device 10 also includes a handle 500 provided on the outer wall of the housing 100. For example, a handle 500 can be provided on the top of the housing 100, and its fulcrum coincides with the center of gravity of the deceleration braking device 10 projected in the third direction, so that the overturning torque of the deceleration braking device 10 is reduced when it is transported.

[0030] In some embodiments, the deceleration braking device 10 further includes two wiring portions 600 that extend at least partially to the outside of the housing 100. The wiring portions 600 are used to lead out the braking resistor 200 cable. A double-protective sealing structure (such as a rubber sealing ring and a locking nut) prevents external environmental contaminants from entering the housing 100, while also providing a stress relief mechanism to prevent the cable from loosening or being damaged under vibration or external force. This layout improves the space utilization of the deceleration braking device 10 and ensures its stability.

[0031] In some embodiments, reference Figures 1 to 5 As shown, the deceleration braking device 10 also includes a mounting bracket 700 located at the bottom of the housing 100, which is used to mount the deceleration braking device 10. The housing 100 is fixedly connected to the mounting bracket 700 through the housing 100 mounting holes, and the deceleration braking device 10 is mounted on the wheel hub wall through the bolt holes on the mounting bracket 700.

[0032] In some embodiments, reference Figure 1 or Figure 5 As shown, the deceleration braking device 10 also includes at least three sets of temperature sensors 800. The temperature sensors 800 are used to collect temperature data of the geometric center area, the heat accumulation area and the heat dissipation airflow outlet area of ​​the braking resistor 200. The temperature sensors 800 and the cooling fan 300 are both electrically connected to the controller of the pitch system. Of course, in some other embodiments, a separate controller can be set to receive the signal from the temperature sensor 800 and control the start and stop of the cooling fan 300.

[0033] It is understandable that the geometric center region of the resistor refers to the centroid projection area of ​​the braking resistor 200 in three-dimensional space. This region, centered on the physical center of the braking resistor 200, radiates outwards to a range of half the distance to the edge, forming a spherical monitoring area. The temperature of the geometric center region reflects the degree of uniformity of heat distribution in space. When the temperature in this region is significantly higher than that in other regions, it indicates that there are homogeneous defects in the resistor material or stress concentration during installation.

[0034] Understandably, the heat accumulation zone refers to the physical space where heat is trapped due to airflow disturbance or boundary effects. It is located at the critical interface between the braking resistor 200 and the inner wall of the housing 100, as well as in the gaps between adjacent braking resistors 200. The heat accumulation zone identifies a weak point in the heat dissipation system. The high temperature in this area directly causes carbonization of the insulation material, which is the main cause of early failure of the braking resistor 200.

[0035] Understandably, the heat dissipation airflow outlet area encompasses the terminal flow field of the heat dissipation airflow before it leaves the braking resistor 200, and the temperature in this area characterizes the actual heat transfer efficiency. The instantaneous heat dissipation efficiency is calculated as a function of the outlet temperature and the temperature difference in the geometric center area. When the instantaneous heat dissipation efficiency is lower than a set threshold, the heat dissipation path is determined to be blocked.

[0036] In some specific implementations, multiple temperature sensors 800 monitor the temperature of different areas of the deceleration braking system in real time. When the temperature sensor 800 detects that the temperature has reached the discharge threshold, the cooling fan 300 is started, and the airflow flows through the cooling fan 300 to the braking resistor 200 and is finally discharged from the heat dissipation hole 120.

[0037] Understandably, the temperature sensor 800 collects temperature data from three areas and fuses them to form a thermal gradient model. When the temperature change rate in a certain area is abnormal, it automatically triggers targeted enhanced heat dissipation, which can accurately eliminate overheated areas while avoiding overall frequency reduction.

[0038] According to the second aspect of this disclosure, reference to Figure 6 As shown, a pitch control system is also provided, which integrates the aforementioned deceleration and braking device 10. When the blade pitch generates regenerative energy, the multiple braking resistors 200 can effectively absorb peak power. When one braking resistor 200 experiences functional degradation or even failure due to overload, aging, or instantaneous impact, and the pitch control system is unable to discharge energy, another braking resistor 200 can still operate normally. This redundancy design can solve the problem of a rapid rise in DC bus voltage threatening the safe operation of the wind turbine when a single braking resistor 200 fails and the pitch control system lacks an energy discharge channel.

[0039] In some embodiments, reference Figure 6As shown, the pitch system includes a pitch shaft housing 20 and at least two deceleration braking devices 10. The two deceleration braking devices 10 are independently installed outside the pitch shaft housing 20 and connected in parallel to the DC bus. The independently installed external housing 100 maintains a thermal isolation distance from the pitch shaft housing 20, minimizing the impact of the braking resistor 200's heat generation on the temperature rise of the pitch shaft housing 20. For example, the deceleration braking device 10 can be installed on the hub wall of the pitch shaft housing 20. The two deceleration braking devices 10 are connected in parallel to the DC bus, establishing a dual current path. When one path is broken, the electrical energy automatically switches to the backup path, ensuring the stable operation of the deceleration braking device.

[0040] In some embodiments, the resistance values ​​of the two deceleration braking devices 10 are equal. When the resistance values ​​of the two deceleration braking devices 10 are equal, the DC bus voltage fluctuation can be evenly distributed to the dual circuits, avoiding overheating due to impedance mismatch. When the DC bus voltage rises sharply, the two resistors start discharging synchronously, and their heat power distribution is symmetrical, avoiding the risk of single-channel overload. In addition, this setting simplifies the spare parts management process, allowing for direct interchange of spare parts during pitch system maintenance without the need for parameter recalibration.

[0041] In some embodiments, the two deceleration and braking devices 10 are fixed in different areas of the wheel hub wall in a staggered manner. The airflow outlet directions of the two housings 100 are spatially asymmetrically distributed. When the cooling fan 300 is started, the high-temperature airflow is discharged along the array of heat dissipation holes 120 of their respective housings 100. The angle formed by the physical stagger can effectively block the convergence path of heat flow and eliminate the phenomenon of hot air recirculation. At the same time, the staggered installation makes the load distribution on the wheel hub wall more uniform, and the risk of local stress concentration in the wheel hub is reduced through the asymmetrical load-bearing design. The staggered spatial layout of the two deceleration and braking devices 10 can both reduce the overall space ratio and avoid the interference of hot air convection through physical stagger.

[0042] In some embodiments, reference Figure 7 As shown, the pitch system also includes an alarm device, which is electrically connected to the temperature sensor 800 of the deceleration braking device 10 and / or the DC bus. The bus overvoltage value is set to V1, and the bus discharge voltage value is V2, where V1 > V2. When braking regenerative energy or grid voltage increases, if the bus voltage is higher than V2, it is further determined whether the pitch system is in operation and the pitch motor brake is not closed. If so, the braking resistor 200 is activated for energy discharge. If the bus voltage is higher than V2, but the pitch system is in a stopped state or the pitch motor brake is closed, the braking resistor 200 is not activated.

[0043] If the braking resistor 200 is not in operation, there is a risk that the bus voltage may be further increased, requiring further assessment. If the bus voltage is higher than V1, the pitch drive will shut off the input rectifier and report a DC bus overvoltage fault. If the bus voltage remains between V1 and V2 and reaches the set delay time, a grid voltage fluctuation alarm will be reported, reminding maintenance personnel to inspect the input voltage.

[0044] Understandably, multiple temperature sensors 800 monitor the temperature data of different areas of the braking resistor 200 in real time. When the temperature is detected to be higher than the threshold, an alarm device is triggered, the cooling fan 300 starts, and the airflow passes through the housing 100 and is discharged through the array of heat dissipation holes 120.

[0045] In some specific implementations, the pitch system monitors the total resistance of housing 100 in real time. When the resistance exceeds a set value, for example, if a set of braking resistors 200 fails and the total resistance doubles, the alarm device reports an anomaly in braking resistor 200. The alarm device achieves systemic safety protection through multi-level hardware linkage. The three monitoring mechanisms (temperature / resistance / voltage) work together to make precise maintenance commands, ensuring the stable and safe operation of the pitch system.

[0046] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0047] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0048] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A deceleration and braking device for a pitch control system, characterized in that, include: The housing includes two independent receiving cavities, and heat dissipation holes communicating with the receiving cavities are respectively provided on opposite sides in a first direction of the housing; A braking resistor is provided in each of the receiving cavities, and the braking resistors in two of the receiving cavities are connected in parallel; and Two sets of cooling fans, one set of cooling fans is connected to one of the receiving cavities, and the other set of cooling fans is connected to another receiving cavity. The cooling fans are used to deliver air to the receiving cavity, so that the air entering the receiving cavity can be discharged through the heat dissipation holes on opposite sides of the first direction of the housing.

2. The deceleration and braking device of the pitch system according to claim 1, characterized in that, The two accommodating cavities are arranged along the second direction; In the second direction, the cooling fan corresponding to one of the housing cavities is located on the side of the housing away from the other housing cavity.

3. The deceleration and braking device of the pitch system according to claim 1, characterized in that, The deceleration and braking device further includes a wire-binding bracket disposed on the outer wall of the housing; and / or The deceleration and braking device also includes a handle located on the outer wall of the housing; and / or The deceleration and braking device also includes two wiring portions that extend at least partially to the outside of the housing.

4. The deceleration and braking device of the pitch system according to claim 1, characterized in that, The deceleration and braking device also includes a mounting bracket located at the bottom of the housing, which is used to mount the deceleration and braking device.

5. The deceleration and braking device of the pitch system according to claim 1, characterized in that, The deceleration and braking device also includes at least three sets of temperature sensors, which are used to collect temperature data of the geometric center area, the heat accumulation area and the heat dissipation airflow outlet area of ​​the braking resistor. The temperature sensor is communicatively connected to the cooling fan.

6. A pitch control system, characterized in that, Includes the deceleration and braking device as described in any one of claims 1-5.

7. The pitch system according to claim 6, characterized in that, The pitch system includes a pitch shaft box and at least two of the aforementioned deceleration and braking devices; The two deceleration and braking devices are independently installed outside the pitch shaft box and are electrically connected in parallel to the DC bus.

8. The pitch system according to claim 7, characterized in that, The resistance values ​​of the two deceleration and braking devices are equal.

9. The pitch system according to claim 7, characterized in that, The two deceleration and braking devices are fixed in different areas of the wheel hub wall in a staggered manner.

10. The pitch system according to any one of claims 7-9, characterized in that, The pitch system also includes an alarm device, which is electrically connected to the temperature sensor and / or DC bus of the deceleration and braking device.

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