I. The wind power industry is upgrading and advancing, and high-altitude maintenance has become a core pain point in wind farm operation.
Under the continuous promotion of the carbon neutrality strategy, domestic onshore mountainous, desert, and tidal flat wind farms, as well as offshore and deep-sea large-capacity wind turbines, have been scaled up. The single-unit capacity of wind turbines has been continuously expanded, and the height of tower frames has been increasing year by year. Wind turbines with a height of over 100 meters have become the mainstream models in wind power development. The wind power braking device, as a core safety component for yaw alignment, main shaft locking, pitch protection, and emergency shutdown, is always installed in the narrow and enclosed cabin, facing the impact of strong winds at high altitudes, the alternating temperature differences between day and night, salt fog and sand dust erosion, and the high-temperature and enclosed working conditions of the cabin. It is an easily damaged core component with a high failure rate and frequent maintenance requirements.
At present, the wind power operation mode mainly involves tower-top high-altitude disassembly and maintenance, as well as parts replacement. High-altitude maintenance of wind power has multiple common industry difficulties. Firstly, the operation risk is high. Maintenance personnel climb the 100-meter tower frame, the operation space in the cabin is narrow and cramped, the installation position of the braking device is limited, the disassembly and installation of bolts, hydraulic debugging, and friction plate replacement operations are difficult, and the high-altitude wind disturbance adds to the continuous safety hazards of high-altitude operations. Secondly, the maintenance cost is high. A single braking maintenance requires the allocation of high-altitude operation tools, lifting equipment, and professional certified maintenance personnel. Offshore wind farms also need to dispatch maintenance vessels. The combined costs of labor, shifts, and machinery are high, and the single maintenance cost remains high. Thirdly, the downtime loss is serious. During braking failure maintenance, the wind turbine must be shut down and locked, and the wind power generation window is forced to be stopped, directly causing the loss of wind farm power generation and compressing the annual revenue of the project. Fourthly, the environmental adaptability is poor. Ordinary braking devices have insufficient corrosion and wear resistance and frequently fail in mountainous areas with low temperatures and in sea areas with salt fog. The frequency of scattered emergency maintenance is high, which disrupts the annual planned maintenance rhythm of the wind farm.
Major wind turbine manufacturers and wind farm operation enterprises have gradually shifted from fault repair-style operation to preventive long-term operation, forcing the improvement and iteration of wind power supporting components. Through material modification, corrosion strengthening, stress optimization, oil circuit stabilization, and self-compensation structures, long-term wind power braking devices have completed process mass production and are compatible with all working conditions. With a longer service life, lower failure probability, and simplified maintenance structure, they reduce the frequency of high-altitude disassembly, shorten the single operation duration, and specifically solve the four major problems of high-altitude maintenance difficulty, high cost, high risk, and high frequency in the wind power industry, helping the wind power component industry upgrade to high quality and enabling lightweight and efficient wind farm operation and control.
II. The shortcomings of conventional wind power braking devices amplify the pressure of high-altitude maintenance in wind power
The common wind power braking devices on the market are suitable for early small-capacity and low-altitude mild wind farms. Their durability, sealing protection, and structural adaptability have limitations. When adapted to high-altitude, offshore, and high-power wind turbines, the component wear is fast, and the derived faults are numerous, directly increasing the burden of high-altitude maintenance and amplifying the maintenance operation pressure. The core shortcomings are concentrated in six major areas.
The lifespan of consumable parts is short, and the frequency of scattered high-altitude replacements is high. The friction plates of conventional braking devices are made of basic semi-metallic materials, with weak heat resistance and corrosion resistance. Under repeated yaw braking and strong wind locking operations, the wear speed is fast. In inland wind farms, 1 to 2 high-altitude replacements of friction components are needed annually, and in salt fog wind farms, the replacement frequency further increases. Moreover, the wear rhythm is unbalanced and cannot match the annual integrated maintenance cycle of the wind turbine, requiring additional high-altitude operations and increasing the number of personnel climbing to high altitudes.
The insufficient sealing level of anti-corrosion measures leads to frequent occurrence of oil leakage and jamming failures at high altitudes. The exposed pins and brake caliper shells of conventional brakes have thin anti-corrosion coatings, and the sealing components are made of ordinary rubber materials. After exposure to high-altitude temperature fluctuations, water vapor, and salt-spray, the sealing parts age and crack, while the metal components rust and accumulate deposits, easily causing hydraulic oil leakage, piston jamming, and yaw slip faults. These faults cannot be predicted and diagnosed on the ground and must be carried out by climbing to the top to clean the oil circuit and replace the sealing components. This is a random emergency maintenance that occupies a large amount of maintenance manpower and resources.
The unreasonable design of the cabin adaptation structure leads to low efficiency of high-altitude disassembly and assembly operations. The brake bolts of the adapted old models are densely arranged and the assembly integration degree is low. The narrow space of the cabin limits the operation of torque wrenches, and the disassembly and assembly process is cumbersome. The complete maintenance of the braking system for a single unit takes a long time. At the same time, there are many separate structural components, and high-altitude disassembly and assembly are prone to component drops and oil circuit contamination problems, increasing the difficulty of the operation and prolonging the downtime of the wind turbine.
The residual stress of the brake is too large, which causes additional damage to the transmission components and expands the maintenance scope. The conventional brake has a large braking impact and uneven force distribution. Long-term operation aggravates the wear and tear of the yaw gear ring, main shaft bearing, and gearbox linkage. The brake failure is accompanied by the damage of the transmission components. Originally, only the braking components needed maintenance, but ultimately, the transmission structure also needs to be inspected and repaired, expanding the high-altitude maintenance scope and increasing the difficulty and material costs of maintenance.
The weak tolerance of the working conditions makes the special maintenance more frequent after extreme weather. In cold weather, the fluidity of the hydraulic oil circuit deteriorates due to low temperatures, and the oil in the high-temperature cabin accelerates deterioration. The conventional brake has no wide-temperature adaptation design. After extreme weather, brake failure, brake force reduction problems occur in a concentrated manner, and the wind farm needs to conduct concentrated high-altitude inspections and maintenance, increasing the workload of operation and maintenance.
The batch performance stability is insufficient, and the control of maintenance materials is difficult. Ordinary brake components produced in small batches have batch differences in material ratio and processing accuracy. The wear rate of the brake components in different wind farms is not the same. The maintenance department needs to prepare multiple specifications of materials for storage, which makes the inventory management cumbersome and increases the difficulty of high-altitude adaptation selection. This further prolongs the on-site operation time.
III. Comprehensive Upgrade for Quality Enhancement, Long-term Wind Turbine Brake Adaptation for Low-Maintenance High-altitude Conditions
This iteration upgrade of the long-term wind turbine brake is based on the research to reduce the burden of high-altitude maintenance for wind power. It is linked with the operation data from the wind farm's maintenance front line. It improves and optimizes from six dimensions: wear-resistant material, all-round anti-corrosion, oil circuit stabilization, structure disassembly and assembly, stress buffering, and gap self-compensation. It weakens the natural wear of components, reduces sudden failures, simplifies the high-altitude disassembly process, and takes into account the safety performance of braking and the convenience of maintenance. It is adapted for all types of wind farms on land and sea for high-altitude installation.
(1) Upgrade of long-term wear-resistant friction material, extending the replacement cycle of consumable parts
Abandoning the traditional semi-metal friction base material, adopt multi-fiber composite modified wear-resistant friction material. It is formed by high-temperature dense molding, with uniform and dense internal fiber structure. It has improved high-temperature braking carbonization, salt spray resistance, and anti-load variation performance. Under continuous locking by strong wind and frequent yaw braking conditions, the friction plate is less likely to be unevenly worn or peeled off, and the wear rate tends to be stable, adapting to the long-term sealed operation environment at high altitudes. At the same time, optimize the composite bonding process of the friction plate steel back, and it does not peel or separate under high-altitude temperature cycling, significantly extending the replacement cycle of friction consumables. The replacement node can be fully integrated into the annual cabin maintenance of the wind turbine, and the scattered high-altitude replacement operations at the halfway point of the year can be cancelled.
(2) Multi-layer all-round anti-corrosion sealing structure, reducing high-altitude leakage and jamming faults
In response to the high humidity, salt spray, and temperature difference environment at high altitudes, reconfigure the brake protection system. The exposed metal components such as the brake caliper, base, and guide pin shaft are protected by a three-layer anti-corrosion process of phosphating passivation, anti-corrosion primer, and weather-resistant paint, improving the resistance to chloride ions, wind sand, acid and alkali erosion, and delaying high-altitude rusting and clogging. A labyrinth-type dust-proof and water-proof structure is added at the interface of the cavity, and an integrated weather-resistant fluorine-based sealing component is used. It is suitable for a wide temperature range of -40℃ to 65℃, and is not prone to hardening or deformation during long-term use. It effectively blocks water vapor and dust from entering the hydraulic cavity, reducing hydraulic oil leakage, piston jamming, and brake pressure relief failures at their source, and reducing the frequency of emergency high-altitude disassembly and maintenance operations.
(3) The design of a stable pressure buffer hydraulic oil circuit reduces the workload of major maintenance tasks
The internal pressure-dividing buffer oil circuit is optimized, and an adaptive pressure-stabilizing valve group is used. It mitigates the impact of braking start and stop oil pressure fluctuations, achieving progressive braking and gradual release of the brake, and reducing the instantaneous impact load of braking. The braking force is evenly transmitted, avoiding hard contact and impact on the yaw gear ring and main shaft transmission structure, reducing the fatigue wear of the core transmission components of the fan, and avoiding high-altitude difficult maintenance operations such as grinding the gear ring and replacing bearings due to brake failures. The dual redundant oil circuit layout automatically supplements pressure when a single oil circuit fluctuates, ensuring the stability of braking in high-altitude wind conditions and reducing the fault troubleshooting operations caused by safety protection shutdowns of the unit.
(4) Optimization of the cabin lightweight disassembly and assembly structure, reducing the duration of high-altitude operations
The external assembly structure is optimized based on the limited working space of the cabin, the layout of the fixed bolt points is optimized, the assembly structure is simplified, and a quick-insertion oil circuit interface is provided. No complex pipeline disassembly is required to complete the disassembly and maintenance. The factory uniformly standardizes the braking clearance, and an internal automatic clearance compensation structure is equipped. After the friction plate wears, it automatically adjusts the clamping stroke, eliminating the need for maintenance personnel to repeatedly adjust and calibrate from high altitudes and re-measure torque. This significantly reduces the maintenance construction time for a single unit and shortens the downtime of the fan, reducing the time spent by maintenance personnel on high-altitude operations.
(5) Reinforcement of the weather-resistant alloy shell, adapting to long-term alternating high-altitude conditions
The brake housing is made of a low-temperature-resistant and high-toughness alloy cast steel material. The stress-optimized integrated reinforcing structure is used to disperse the alternating impact stress of high-altitude gusts. The shell is less prone to deformation and cracking, and the bolts are less likely to loosen and slip. It is suitable for high-altitude complex conditions such as high-altitude cold waves, coastal exposure, and sea wind waves. The structural durability is improved, and the large components of the shell and base do not need to be reinforced by high-altitude inspections and repairs regularly. Special maintenance procedures for the structure are reduced, and the service life of the entire machine is improved.
(6) Standardized factory calibration, reducing the threshold for high-altitude operation and maintenance
The product is completed with full-item calibration of braking torque, oil pressure values, and braking clearance. The parameters are solidified without on-site calibration, and it is compatible with mainstream fan hydraulic control systems and cabin installation bases. The installation dimensions of new and old models are common, and existing fans can be installed without modifying the base or oil circuit lines. Maintenance personnel can directly install them, reducing the technical threshold for high-altitude construction and maintenance and reducing the investment in professional maintenance personnel.
Four. Implementation of multi-dimensional burden reduction, solving the core problem of high-altitude maintenance for the long-term brake mechanism
Relying on the comprehensive quality improvement of components, the long-term wind power mechanism brake has solved the pain points of high-altitude maintenance in wind power, reconstructing a low-cost, low-risk, and planned maintenance system for the wind farm.
Reduce the frequency of climbing operations and lower the safety risks of high-altitude operations. With the long-term durability performance of the components, the failure rate of braking faults and consumable wear failures has significantly decreased, and scattered emergency climbing operations have been greatly reduced. Maintenance personnel only need to complete the inspection and maintenance of the braking components during the annual unified maintenance period, reducing the number of climbing operations throughout the year, avoiding the risks of falling, bumping, and oxygen deficiency in high-altitude gusty and enclosed space operations, and conforming to the safety control standards for high-altitude operations in wind power.
Reduce the total maintenance expenses over the entire period and alleviate the financial pressure on the wind farm. On the one hand, the frequency of component procurement is reduced, and the purchase volume of friction plates, seals, hydraulic oil consumables, and other materials is decreased, revitalizing the maintenance inventory funds.
On the other hand, the frequency of installing lifting equipment, operating vessels, and dispatching certified personnel is reduced, eliminating the need for multiple rental fees for shifts and machinery. The cost reduction in offshore wind farm operation is more significant. At the same time, transmission-related losses are avoided, and the investment in major repairs and replacements of gear rings and main shafts is reduced. The overall budget for wind farm operation is lowered.
Shortening the downtime of wind turbines can recover the power generation income of the wind farm. In the past, single high-altitude maintenance for braking faults took a long time and had a cumbersome process. During the high wind window period, the loss due to shutdown was large. The new brake is easy to disassemble and assemble, eliminating the need for frequent debugging. The maintenance operation time is shortened, and there are no random faults that cause shutdowns, ensuring the effective grid connection time of the wind turbine and stabilizing the monthly and annual power generation of the wind farm, thereby enhancing the operating income of the wind power project.
Regulating the overall operation rhythm of the wind farm to achieve planned maintenance. Long-term brakes have a balanced wear rate, and the maintenance nodes of the braking components of all wind farm units are unified. The maintenance department can formulate an annual maintenance plan, conduct concentrated and batch high-altitude maintenance, and unify the preparation of materials, scheduling, and construction. This eliminates the scattered, sudden, and disorderly maintenance mode in the past and improves the efficiency of wind farm maintenance management.
Adapting to both onshore and offshore wind farms, as well as retrofitting and new machine integration. The product can be adapted to onshore mountainous, desert, and cold regions wind farms, as well as high-salt-spray and large-capacity offshore wind farms. It covers all categories of braking scenarios such as yaw braking, main shaft braking, and pitch braking. The new wind turbines can be pre-installed with the original factory, ensuring the compatibility of the entire machine maintenance. The old and outdated wind turbines can be directly replaced at high altitudes, reducing the retrofitting threshold and facilitating the implementation of long-term maintenance. Subsequent offshore and onshore wind power development will continue to expand to deeper waters, higher altitudes, and larger power capacity models. The standards for high-altitude operation and maintenance control, as well as the durability standards for components, will continue to improve. The wind power braking supporting industry will continue to deeply research and develop technologies such as anti-corrosion, wear resistance, maintenance-free, and simple disassembly and assembly. It will meet the needs of frontline high-altitude operation and maintenance, and continuously optimize the compatibility performance of braking components. Relying on standardized mass production and customized iterations of operating conditions, it will continuously output long-term, low maintenance, and high safety wind power braking products. It will continuously solve the problems of high-altitude wind power operation and maintenance, improve the supporting system of high-end wind power components, and help the wind power industry achieve safe, efficient, low-cost, and long-term development.
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