Transformation method and system for variable pitch system of sea-mounted fan

Abstract

The invention relates to the technical field of fan variable-pitch systems, in particular to a method and a system for transforming a variable-pitch system of a sea-mounted fan, which comprises the following steps: analyzing the sea-mounted fan, obtaining the existing problem of the variable-pitch system, designing a transformation scheme of the variable-pitch system of the fan according to the existing problem, and transforming and debugging the variable-pitch system on site according to the transformation scheme and equipment transformation implementation conditions. The variable pitch system of the sea-mounted fan is improved, an original direct-current variable pitch motor of the fan is replaced with an alternating-current permanent magnet synchronous motor, and a super capacitor is used for replacing a lead-acid battery to serve as a back-up power source of the variable pitch system. The durability of the device is improved, and the work such as battery replacement and motor carbon brush cleaning which originally need frequent maintenance is reduced. The super capacitor has a longer life cycle, and the replacement frequency is reduced, so that the long-term maintenance cost and the spare part consumption cost are reduced.

Description

Technical Field

[0001] The present invention relates to the field of wind turbine pitch control systems, and in particular to a method and system for modifying a wind turbine pitch control system installed offshore. Background Art

[0002] With the continuous growth of global energy demand and the high attention paid to renewable energy, wind energy has been widely used as a clean energy around the world. In recent years, the rapid development of wind power generation technology, especially in the field of offshore wind power, has made remarkable progress. Offshore wind power has higher wind speeds and more stable wind energy resources than onshore wind power, so it has greater power generation potential. However, the operation and maintenance of offshore wind farms face extremely severe challenges. Among them, the reliability and efficiency of wind turbines are key factors affecting the overall performance of offshore wind farms.

[0003] In modern wind turbines, the pitch control system is a core component to ensure efficient and stable operation of the wind turbine. The system controls the power output of the wind turbine by adjusting the angle of the wind turbine blades to adapt to different wind speeds and ensure safe operation of the wind turbine under overload or low wind speed conditions. As the scale of wind turbines continues to increase, the technical requirements for the pitch control system are also increasing. The traditional pitch control system has poor reliability and frequent failure rates, causing large power losses and loss of benefits.

[0004] In response to the shortcomings of these existing technologies, we have invented and proposed a method and system for modifying the pitch system of offshore wind turbines. By deeply analyzing the pitch system of existing offshore wind turbines, we identified the key problems in the system, further optimized the structure and control strategy of the pitch system, and made targeted improvements to the shortcomings of the existing pitch system drive mode and backup power supply. This solution not only takes into account the performance improvement of the system itself, but also combines the actual conditions on site to provide a feasible implementation plan for on-site modification and commissioning of wind turbines, which has obvious advantages in improving system stability, reducing maintenance costs, and improving the overall operation and maintenance efficiency of wind farms. Summary of the invention

[0005] In view of the above-mentioned problems, the present invention is proposed.

[0006] Therefore, the technical problem solved by the present invention is: to solve the problem of frequent failures of the offshore wind turbine pitch system, by technically transforming the wind turbine pitch system to improve the operating stability of the offshore wind turbine and solve the problem of frequent failures of the offshore wind turbine pitch system.

[0007] In order to solve the above-mentioned technical problems, the present invention provides the following technical solutions: a method for modifying an offshore wind turbine pitch system, comprising: analyzing the offshore wind turbine to obtain existing problems of the pitch system; designing a modification plan for the wind turbine pitch system according to the existing problems; and modifying and debugging the pitch system on site according to the modification plan and equipment modification implementation conditions.

[0008] As a preferred solution of the method for modifying the variable pitch system of an offshore wind turbine described in the present invention, the existing problems of the variable pitch system include poor reliability of the original variable pitch system, large power generation loss, low electronic control integration and stability, and frequent failures.

[0009] As a preferred solution of a method for modifying a pitch system of an offshore wind turbine described in the present invention, the modification scheme of the pitch system includes: modifying a DC pitch system to an AC pitch system, modifying a lead-acid battery to a supercapacitor, and optimizing a pitch electrical circuit.

[0010] As a preferred solution of the offshore wind turbine pitch system modification method described in the present invention, the on-site modification and debugging of the pitch system includes replacing the original driver, motor, and backup power supply, redesigning the pitch control cabinet and battery cabinet space, and simplifying the electrical circuit.

[0011] As a preferred solution of the offshore wind turbine variable pitch system modification method described in the present invention, the simplified electrical circuit includes replacing an AC drive and a permanent magnet synchronous motor, using an integrated AC drive, and having the necessary 24V power supply and charging module built in, without the need for additional chargers and conversion lines.

[0012] As a preferred solution of the method for modifying the pitch system of an offshore wind turbine described in the present invention, the permanent magnet synchronous motor includes a permanent magnet embedded in the rotor to generate a constant magnetic field, which interacts with the AC electromagnetic field generated by the stator. The AC permanent magnet synchronous motor in the pitch system provides power output and emergency protection functions.

[0013] As a preferred solution of the method for modifying the variable pitch system of an offshore wind turbine described in the present invention, the conditions for implementing the equipment modification include arranging the project modification to be carried out in the low wind season.

[0014] Another object of the present invention is to provide an offshore wind turbine pitch system modification system, which can improve the operating stability of the offshore wind turbine and solve the problem of frequent failures of the offshore wind turbine pitch system by performing technical modifications to the wind turbine pitch system.

[0015] In order to solve the above technical problems, the present invention provides the following technical solutions: a system for modifying the pitch system of an offshore wind turbine, characterized in that it comprises: a module for analyzing existing problems, a module for designing modification solutions, and a module for implementing modification;

[0016] The existing problem analysis module analyzes the offshore wind turbine to obtain the existing problems of the variable pitch system;

[0017] The design and transformation scheme module designs a transformation scheme for the wind turbine pitch system based on the existing problems;

[0018] The transformation implementation module transforms and debugs the variable pitch system on site according to the transformation plan and equipment transformation implementation conditions;

[0019] A computer device includes a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the steps of the above-mentioned method for modifying a variable pitch system of an offshore wind turbine are implemented.

[0020] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of a method for modifying a variable pitch system of an offshore wind turbine as described above.

[0021] The beneficial effects of the present invention are as follows: by replacing the core components and overall transformation of the variable pitch system of the offshore wind turbine, the failure rate is significantly reduced, the stability of the operation of the offshore wind turbine is improved, the downtime caused by failures is reduced, and the availability of the unit is greatly improved, so that the wind farm can generate electricity more efficiently, thereby improving economic benefits.

[0022] By replacing the original wind turbine DC pitch motor with an AC permanent magnet synchronous motor and using supercapacitors instead of lead-acid batteries as the backup power supply for the pitch system, the durability of the equipment is improved, and the work of frequent maintenance such as battery replacement and motor carbon brush cleaning is reduced. Supercapacitors have a longer life cycle and reduce the frequency of replacement, thereby reducing long-term maintenance costs and spare parts consumption costs.

[0023] After the transformation, the wind turbine's power generation efficiency has been significantly improved, and the average annual power loss has been significantly reduced. In addition, due to the reduced demand for spare parts and the extended equipment life after the transformation, a large amount of operation and maintenance costs can be saved each year, allowing the project to achieve a return on investment in less than five years. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0025] Figure 1 A flow chart of a method for modifying a variable pitch system of an offshore wind turbine provided in accordance with an embodiment of the present invention.

[0026] Figure 2 An overview of the MOOG pitch system after DC to AC conversion, providing a method for modifying the pitch system of an offshore wind turbine according to an embodiment of the present invention. DETAILED DESCRIPTION

[0027] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0028] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0029] Example 1

[0030] Reference Figure 1-Figure 2 , which is an embodiment of the present invention, a method for modifying a pitch system of an offshore wind turbine, comprising:

[0031] S1: Analyze offshore wind turbines and identify existing problems with the variable pitch system.

[0032] It should be noted that existing problems with the variable pitch system include poor reliability of the original variable pitch system, large power generation losses, low electronic control integration and stability, and frequent failures.

[0033] In the embodiment of the present application, by analyzing the existing problems of the offshore wind turbine, it is concluded that the existing offshore wind turbine adopts a DC variable pitch system, the DC variable pitch motor has been running for more than 12 years, the motor carbon brush is seriously worn, and it is easy to cause a variable pitch failure, which poses certain safety hazards; the variable pitch driver frequently reports errors in strong winds, the internal components of the driver are aging, and there are problems with matching with the motor, resulting in alarms, which seriously affects the power generation of the unit; the system variable pitch A and B encoders frequently jump, which seriously affects the normal operation of the unit; the variable pitch system brake resistor is installed in the cabinet, and the resistor is easy to overheat and rupture during emergency retraction, causing damage to other components in the cabinet, which poses certain safety hazards; the DC system controls the DC variable pitch system. The peripheral electrical design is complex, and normal variable pitch, low penetration, and emergency retraction are controlled by related hardware electrical circuits. Because the system has been running for more than 12 years, multiple electrical components such as battery retraction contactor, battery brake contactor, battery monitoring module, and delay relay have gradually aged and become stuck. Each blade is equipped with a battery cabinet and a shaft cabinet, sharing a set of chargers. The system structure is complex, occupies a large space, has a large maintenance workload, and has poor reliability. In addition, the original variable pitch system adopts a DC drive solution, and the system is equipped with a DC drive and a DC motor. Since the power density of the DC motor is small, it is easy to heat up during operation, and a cooling fan or radiator is required to dissipate the heat of the motor. At the same time, the DC motor contains carbon brushes and commutators, and the accumulation of carbon powder is easy to cause short circuit failures, thereby damaging the motor. Therefore, the DC motor not only has low operating efficiency and is prone to damage, but also requires regular maintenance of the fan, radiator and carbon brushes, which reduces the overall utilization of the unit, increases maintenance costs, increases the system failure rate, and affects safety.

[0034] The existing backup power supply of Haizhuang wind turbines uses lead-acid batteries, which have a short life cycle and poor low-temperature characteristics. Practice shows that due to the cold winter climate, the battery needs to be replaced once every two years, wasting a lot of manpower and funds. Figure 1 As shown in S1.

[0035] S2: Based on the existing problems, design a transformation plan for the wind turbine pitch system.

[0036] It should be noted that the modification plan for the pitch system includes changing the DC pitch system to an AC pitch system, changing the lead-acid battery to a supercapacitor, and optimizing the pitch electrical circuit.

[0037] Furthermore, the overall idea of ​​changing the DC pitch to AC pitch is to transform the MOOG DC pitch system that has been put into operation on site, while keeping the original structure and the cable connection method between the cabinets unchanged. The integrated driver and permanent magnet synchronous motor are used to replace the original DC driver and DC motor, and the DC pitch system is changed to an AC pitch system. The original MOOG system directly switches to the battery circuit for pitch adjustment during emergency retraction. This transformation ensures that under normal power grid conditions, the 400V power grid is used first to adjust the pitch. When a power grid failure occurs, the backup power supply is used for controllable pitch adjustment, ensuring the safety of the unit and extending the service life of the backup power supply. The modified motor is directly fixed to the original motor by bolts, and through the customization of the motor interface, the power line and encoder line of the original system are used to achieve seamless replacement of the modified motor. The modified pitch motor does not require a cooling fan or a motor heater. The motor brake is powered by a low-voltage 24VDC, and no absolute encoder is required. Using a rotary transformer, there are no carbon brushes and commutators. The modified motor has a high power density, is not easy to heat up, and has excellent heat dissipation performance. In addition, the modified variable pitch drive adopts a domestically produced dedicated variable pitch drive and integrates a 24V switching power supply and charger to drive the AC system.

[0038] The backup power supply of the variable pitch system is changed from lead-acid battery to supercapacitor. A single supercapacitor cabinet is arranged in the original battery cabinet space to simplify charging and electrical connection. At the same time, each cabinet uses the built-in charger of the drive to charge the capacitor, eliminating the original charger, and the charging speed is very fast. Redundant components such as motor cooling fan and brake circuit heater are eliminated. The complex power switching logic is eliminated. The AC variable pitch system is always controlled by the drive, and is directly powered by the supercapacitor during emergency feathering.

[0039] After the transformation, the system has simplified the charging circuit. The motor drive circuit during emergency retraction does not require the motor power switching control circuit. The motor is always controlled by the driver. The AC permanent magnet synchronous motor brake is powered by 24VDC, so there is no need for an external brake circuit inside the variable pitch system. The 24VDC switching power supply that comes with the domestic driver can be used for power supply. Figure 2 shown.

[0040] S3: According to the transformation plan and equipment transformation implementation conditions, the variable pitch system is transformed and debugged on site.

[0041] It should be noted that the on-site transformation of the fan unit according to the electrical and program design includes shutting down the fan unit and isolating it safely, and replacing and wiring the original electrical equipment according to the design plan.

[0042] Furthermore, based on the size of the original control cabinet and backup power battery of the hub, a professional manufacturer will select and plan the cabinet layout plan according to the cabinet size. In order to successfully complete the installation of the new equipment, before the replacement, professional personnel will conduct on-site measurements and select matching drives, pitch motors and supercapacitors based on the measurement data, and design a cabinet layout plan that meets the requirements.

[0043] During the hoisting operation, it is necessary to shut down the wind turbine and put it into maintenance mode, disconnect all power switches on the nacelle and hub, lock the wind wheel pin, and apply the high-speed shaft brake to ensure that the high-speed shaft brake is effective to prevent accidental rotation. Remove the electrical connection lines of the hub, including the main control system, communication lines and power lines, remove the bolts connecting the drive motor and the pitch gearbox flange in the hub, take out the pitch motor, move the removed pitch motor and pitch battery from the hub to the nacelle, and use the nacelle small crane to lift them to the ground, lift the new pitch motor and pitch battery to the nacelle, and move the core spare parts from the nacelle to the hub for installation and fixation. After the motor and supercapacitor are installed, pack up all tools, auxiliary materials, and debris out of the hub, turn the wind wheel so that the other blade is facing down, and repeat the above steps to complete the replacement of the core components on the three surfaces of the hub.

[0044] Furthermore, after completing the replacement of the mechanical part, it is necessary to restore the electrical connection between the hub and the control cabinet, and carry out wiring and debugging work, including: connecting the wire binding bracket and the inter-cabinet cables, completing the remaining wiring in the cabinet, connecting the wiring between the control cabinet cabinets and between the cabinets and the motor. The hub needs to be re-drilled and tapped to fix the wire card according to the general assembly wiring standard. After completion, wiring can be started. After the wiring is completed, the line is checked for the final time, and then the power is turned on, and check whether the power signal lights of each line are correct. After the power is turned on normally, the pitch debugging work can be started, including: running the wind turbine at different wind speeds, testing the stability of the pitch system, testing the high and low voltage ride-through capability of the system, and ensuring compliance with the wind turbine operating specifications. After completion, the hub is cleaned and the unit is restored to an operational state, the main control program configuration is changed to match it with the modified pitch system, and it is connected to the grid for operation without any faults.

[0045] It should be noted that the conditions for implementing equipment transformation include arranging the transformation of offshore wind turbines to be completed during the small monsoon season. The power generation of wind farms during the small monsoon season is relatively low. Arranging the transformation during the small monsoon season can minimize the power loss caused by the shutdown of wind turbines for transformation, thereby reducing the economic impact. At the same time, the wind speed is relatively low during the small monsoon season, which is conducive to the safety of construction activities such as hoisting, disassembly, and equipment replacement. Under high wind speed conditions, there are greater safety hazards in high-altitude operations, while low wind speeds can reduce this risk. The small monsoon season is usually a low-load operation period for wind farms. Transformation during this period can better coordinate construction resources and avoid affecting normal production operations.

[0046] Example 2

[0047] As an embodiment of the present invention, the present invention provides the following technical solutions: a system for modifying a pitch system of an offshore wind turbine, comprising: a module for analyzing existing problems, a module for designing a modification solution, and a module for implementing a modification;

[0048] The existing problem analysis module analyzes the offshore wind turbine to obtain the existing problems of the variable pitch system;

[0049] The design and transformation scheme module designs a transformation scheme for the wind turbine pitch system based on the existing problems;

[0050] The transformation implementation module transforms and debugs the variable pitch system on site according to the transformation plan and equipment transformation implementation conditions;

[0051] This embodiment further provides a computing device, which is applicable to a method for modifying a pitch system of an offshore wind turbine, and includes:

[0052] Memory and processor; the memory is used to store computer executable instructions, and the processor is used to execute computer executable instructions to implement a method for modifying an offshore wind turbine pitch system as proposed in the above embodiment.

[0053] The storage medium proposed in this embodiment and the offshore wind turbine pitch system modification method proposed in the above embodiment belong to the same inventive concept. The technical details not fully described in this embodiment can be referred to the above embodiment, and this embodiment has the same beneficial effects as the above embodiment.

[0054] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program codes.

[0055] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0056] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0057] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for modifying a pitch system of an offshore wind turbine, characterized in that: include: Analyze offshore wind turbines and find out the existing problems of variable pitch systems; According to the existing problems, a transformation plan for the wind turbine pitch system is designed; According to the transformation plan and equipment transformation implementation conditions, the variable pitch system is transformed and debugged on site.

2. A method for modifying a pitch system of an offshore wind turbine according to claim 1, characterized in that: Existing problems with the variable pitch system include poor reliability of the original variable pitch system, large power generation loss, low electronic control integration and stability, and frequent failures.

3. A method for modifying a pitch system of an offshore wind turbine as claimed in claim 2, characterized in that: The modification plan for the pitch system includes changing the DC pitch system to an AC pitch system, changing the lead-acid battery to a supercapacitor, and optimizing the pitch electrical circuit.

4. A method for modifying a pitch system of an offshore wind turbine as claimed in claim 3, characterized in that: The on-site transformation and debugging of the pitch control system includes replacing the original driver, motor, and backup power supply, redesigning the space of the pitch control cabinet and the battery cabinet, and simplifying the electrical circuit.

5. A method for modifying a pitch system of an offshore wind turbine as claimed in claim 4, characterized in that: The simplified electrical circuit includes replacing an AC drive and a permanent magnet synchronous motor, adopting an integrated AC drive, and having a built-in necessary 24V power supply and charging module, without the need for an additional charger and conversion line.

6. A method for modifying a pitch system of an offshore wind turbine according to claim 5, characterized in that: The permanent magnet synchronous motor includes a permanent magnet embedded in the rotor to generate a constant magnetic field, which interacts with the AC electromagnetic field generated by the stator. The AC permanent magnet synchronous motor in the variable pitch system provides power output and emergency protection functions.

7. A method for modifying a pitch system of an offshore wind turbine according to claim 6, characterized in that: The conditions for implementing the equipment transformation include arranging the project transformation during the low wind season.

8. A system for modifying a offshore wind turbine pitch system according to any one of claims 1 to 7, characterized in that: include: Analyze existing problem module, design transformation plan module, and implement transformation module; The existing problem analysis module analyzes the offshore wind turbine to obtain the existing problems of the variable pitch system; The design and transformation scheme module designs a transformation scheme for the wind turbine pitch system based on the existing problems; The transformation implementation module transforms and debugs the variable pitch system on site according to the transformation plan and equipment transformation implementation conditions.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of a method for modifying a pitch system of an offshore wind turbine as described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of a method for modifying a pitch system of an offshore wind turbine as described in any one of claims 1 to 7 are implemented.

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