A single point mooring floating wind power system, wind farm, substation

Abstract

The single-point mooring floating wind power system is provided by the disclosure, by adopting a regular triangle three-column floating body structure, connecting an anchor base through a tension leg at the bottom of a first column, setting a mooring rotor at a connecting point and fixing through a plurality of mooring cables, so that the system has higher stability in a deep sea environment; by arranging a large-diameter wind turbine and two small-diameter wind turbines on the floating body and optimizing the matching relationship between the wind wheel diameter and the floating body size, the wind energy utilization rate is improved; by adjusting the wind-approaching angle of the wind turbine in real time through a yaw control unit, a compensating moment is generated in the floating body plane, the rotating effect caused by the sea current is effectively offset, and the operation stability and power generation efficiency of the system are improved; at the same time, based on the dynamic yaw adjustment strategy of the different sea current direction and wind direction angle, the system is adapted to the complex marine environment, and the reliability and applicability of the wind power system are improved.

Description

Technical Field

[0001] This invention relates to the field of power generation technology, and in particular to a single-point moored floating wind power system, a wind farm, and a substation. Background Technology

[0002] With the global energy structure shifting towards renewable energy, offshore wind power technology is developing rapidly. Compared to onshore wind power, offshore wind power is constrained by the marine environment and faces more complex challenges in meteorological, hydrodynamic, and engineering structural design. Floating wind power systems, due to their suitability for deep-sea areas, abundant wind energy resources, and flexible construction, have become an important direction for the future development of offshore wind power. Among them, single-point mooring floating wind power systems, as a new type of mooring method, have stronger adaptability and stability, and are suitable for wind energy development in deeper sea areas.

[0003] However, existing floating wind power systems mainly rely on multi-point mooring or tension leg structures, making them highly susceptible to environmental factors such as wind, currents, and waves. This makes them prone to irregular movement, affecting power generation efficiency and equipment lifespan. Especially in areas with strong ocean currents, the wind direction and current direction may not align, causing the floating body to experience rotational torque, affecting the turbine's angle of attack and thus reducing power generation efficiency. Current wind turbine yaw control technology is primarily based on single-turbine systems, making it difficult to effectively compensate for the rotational torque caused by ocean currents. Summary of the Invention

[0004] A first aspect of this disclosure provides a single-point moored floating wind power system, the system comprising:

[0005] A floating body, comprising three columns, with any two columns connected in pairs to form an equilateral triangle structure with a side length of L, the floating body being used to float in seawater;

[0006] Tension leg connects the bottom end of the first column of the float to the top end of the anchoring foundation, the bottom end of the anchoring foundation is fixed to the seabed, and a mooring rotor is installed at the connection point between the tension leg and the first column. The mooring rotor is connected to multiple mooring cables, and the end of the mooring cable away from the mooring rotor is fixed to the seabed.

[0007] The first wind turbine is fixedly installed on the top of the first column and is used to generate electricity using wind energy.

[0008] The second and third fans are fixedly installed on the top of the second and third columns of the float, respectively. The first, second and third fans transmit electrical energy through cables. The impeller diameters of the second and third fans are equal and smaller than the impeller diameter d1 of the first fan. The impeller diameters d2 of the second and third fans satisfy: 2·d2<L.

[0009] In conjunction with the first aspect, the system further includes a yaw control unit for controlling the windward angle of the first and second wind turbines, so that the first and second wind turbines generate a compensating torque around the mooring rotor in the plane of the floating body to counteract the rotational torque generated by the ocean current on the floating body, specifically including:

[0010] Real-time acquisition of the angle α between ocean current direction and wind direction;

[0011] Adjust the yaw angles β1 and β2 of the first and second fans according to the α value so that the compensating torque generated by the fans satisfies:

[0012] F3·sinα·L·cos30°·2 / 3=F1·cosβ1·L·cos30°+F2·cosβ2·L·cos30°, where F1 and F2 are the wind forces experienced by the first and second wind turbines, respectively, and F3 is the force exerted by the ocean current on the floating body.

[0013] In conjunction with the first aspect, the rotor diameter d1 of the first wind turbine and the rotor diameter d2 of the second and third wind turbines satisfy the following condition: 0.35d1 < d2;

[0014] The total swept area of ​​the second and third fans is 2×0.5πd² 2 The swept area of ​​the first fan is 0.25πd1 2 satisfy:

[0015] 0.5×0.25πd1 2 <2×0.5πd2 2 <4×0.25πd1 2 .

[0016] In conjunction with the first aspect, the yaw control unit adjusts the yaw speed according to the angle α between the ocean current direction and the wind direction, specifically including:

[0017] When α ≤ 15°, the yaw speed ≤ 0.1° / second;

[0018] When 15°<α≤30°, the yaw speed ≤0.3° / second;

[0019] When 30°<α≤60°, the yaw speed ≤0.5° / second;

[0020] When α > 60°, the yaw speed is ≤ 0.7° / second.

[0021] In conjunction with the first aspect, the side length L of the equilateral triangle of the floating body and the diameter d1 of the first wind turbine rotor satisfy L≥d1.

[0022] In conjunction with the first aspect, the length of the mooring cable is not less than 5 times the side length of the float.

[0023] In conjunction with the first aspect, the top of the anchoring foundation is provided with a universal joint, which is hinged to the tension leg.

[0024] In conjunction with the first aspect, the yaw control unit includes wind, wave and current sensors, and the wind, wave and current sensor group includes an ultrasonic anemometer, a wave height meter and a current meter installed at the centroid of the buoy. The data of the wind, wave and current sensor group is transmitted to the yaw control unit via wired or wireless means.

[0025] A second aspect of this disclosure provides an offshore wind farm, characterized in that it includes a plurality of the aforementioned single-point moored floating wind power systems.

[0026] A third aspect of this disclosure provides an offshore substation, characterized in that it includes at least one of the aforementioned offshore wind farms.

[0027] Beneficial Effects: This disclosure provides a single-point moored floating wind power system, wind farm, and substation. By adopting an equilateral triangular three-column floating structure and connecting the anchor foundation at the bottom of the first column via tension legs, and simultaneously setting a mooring rotor at the connection point and securing it with multiple mooring cables, the system achieves higher stability in deep-sea environments. By arranging one large-diameter wind turbine and two small-diameter wind turbines on the floating body and optimizing the matching relationship between the turbine diameter and the floating body size, wind energy utilization is improved. The yaw control unit adjusts the wind turbine's angle of attack in real time, generating a compensating torque within the floating body plane, effectively counteracting the rotational effect caused by ocean currents, and improving the system's operational stability and power generation efficiency. Furthermore, the dynamic yaw adjustment strategy based on the angle between different ocean current directions and wind directions allows the system to adapt to complex marine environments, improving the reliability and applicability of the wind power system. Attached Figure Description

[0028] Figure 1 This is a three-dimensional structural diagram of a single-point moored floating wind power system according to an embodiment of the present disclosure;

[0029] Figure 2 This is a top view of the fan according to an embodiment of the present disclosure;

[0030] Figure 3 Force diagram of a single-point moored floating wind power system when the wind direction and ocean current are in the same direction;

[0031] Figure 4 This diagram illustrates the force state of a single-point moored floating wind power system when wind direction and ocean current direction are opposite. Detailed Implementation

[0032] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with those disclosed herein.

[0033] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. The singular forms “a,” “the,” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0034] It should be understood that although the terms first, second, third, etc., may be used to describe various information in embodiments of this disclosure, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, first information may also be referred to as second information without departing from the scope of embodiments of this disclosure, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to a determination."

[0035] With the rapid development of offshore wind power, its construction is expanding to deeper and more distant sea areas. Floating wind turbines, with their excellent adaptability to deep-water environments, are showing broad market prospects.

[0036] Compared to traditional floating wind turbines, single-point moored floating wind turbines install multiple turbines on a single floating foundation. This not only effectively distributes the construction cost of the floating foundation, but also allows for real-time adjustment of the turbine's windward angle through yaw control. This enables the system to generate a compensating torque within the floating plane, effectively counteracting the rotational effect caused by ocean currents and improving the system's operational stability and power generation efficiency.

[0037] like Figure 1 The diagram shown is a three-dimensional structural schematic of a single-point moored floating wind power system according to an embodiment of this disclosure, including:

[0038] The float 110 includes three columns, with any two columns connected in pairs to form an equilateral triangle structure with a side length of L. The float is used to float in seawater.

[0039] Tension leg 120 connects the bottom end of the first column 1101 of the floating body to the top end of the anchoring base 130. The bottom end of the anchoring base 130 is fixed to the seabed. A mooring rotor (not shown) is installed at the connection point between the tension leg 120 and the first column 1101. The mooring rotor is connected to multiple mooring cables 140 (only a single cable is shown in the diagram). The end of the mooring cable 140 away from the mooring rotor is fixed to the seabed.

[0040] The first wind turbine 150 is fixedly installed on the top of the first column 1101 and is used to generate electricity using wind energy.

[0041] The second fan 160 and the third fan 170 are fixedly installed on the top of the second column 1102 and the third column 1103 of the float, respectively. The first fan 150, the second fan 160 and the third fan 170 transmit electrical energy through cables. The impeller diameters of the second fan 160 and the third fan 170 are equal and smaller than the impeller diameter d1 of the first fan 150. The impeller diameters d2 of the second fan 160 and the third fan 170 satisfy: 2·d2<L.

[0042] Specifically, the float (110) is the basic support structure of the system, consisting of three columns (1101, 1102, 1103). The three columns are connected in pairs to form an equilateral triangle arrangement with a side length of L. The float floats on the sea surface, and the equilateral triangle arrangement improves the stability of the float in seawater and provides an installation platform for the wind turbine.

[0043] It should be noted that the connection structure between the three columns is not specifically limited in this embodiment.

[0044] Preferred, such as Figure 1 As shown, the three columns are connected at both the top and bottom with connectors parallel to the sea level (floating plane), and reinforcing members are arranged between the top and bottom connectors to form a triangular structure with the connectors, further enhancing stability.

[0045] Optionally, reinforcing members may also be provided between the top connectors, between the bottom connectors, and between the top connectors and the bottom connectors. This embodiment does not impose specific limitations here.

[0046] It should be noted that the connectors are not limited to the top and bottom of the column. An unlimited number of connectors can be installed at different vertical positions of the column according to actual needs.

[0047] Tension leg (120) connects the bottom end of the first column (1101) of the float to the anchorage foundation (130), the bottom end of which is fixed to the seabed. The function of tension leg is to restrain the vertical movement of the float by tension, so as to keep it in balance at sea.

[0048] The mooring rotor (not shown) is installed at the bottom connection point of the first column (1101), connected to the tension leg, and connected to the seabed through multiple mooring cables (140, only a single cable is shown in the figure), so that the float can rotate around the overall vertical structure formed by the first column 1101, the tension leg 120, and the anchoring foundation 130.

[0049] Beneficial effects: This design allows the float to adjust to the wind and current direction to a certain extent, thereby reducing structural stress and improving system stability.

[0050] This system has three fans (150, 160, and 170) installed on the three columns of the float:

[0051] First fan (150): Fixedly installed at the top of the first column (1101), it is the main fan of the system and has a large impeller diameter.

[0052] The second fan (160) and the third fan (170) are installed on the top of the second column (1102) and the third column (1103) respectively. The diameter of the impellers of the two fans is equal and smaller than that of the first fan.

[0053] See Figure 2 The arrangement and size of the fans satisfy 2·d2<L. This constraint ensures that the rotors of the second fan (160) and the third fan (170) will not interfere with each other, while avoiding the impact of excessively large rotors on the overall stability of the floating body.

[0054] All three wind turbines (150, 160, and 170) transmit electrical energy via cables, achieving efficient wind energy conversion and grid-connected power generation. This layout not only improves the wind energy utilization rate per unit floating body but also optimizes the collaborative operation of multiple wind turbines to ensure overall power generation efficiency.

[0055] Furthermore, the system also includes a yaw control unit for controlling the windward angle of the first and second wind turbines, so that the first and second wind turbines generate a compensating torque around the mooring rotor in the plane of the floating body to counteract the rotational torque generated by the ocean current on the floating body, specifically including:

[0056] Real-time acquisition of the angle α between ocean current direction and wind direction;

[0057] Adjust the yaw angles β1 and β2 of the first and second fans according to the α value so that the compensating torque generated by the fans satisfies:

[0058] F3·sinα·L·cos30°·2 / 3=F1·cosβ1·L·cos30°+F2·cosβ2·L·cos30°, where F1 and F2 are the wind forces experienced by the first and second wind turbines, respectively, and F3 is the force exerted by the ocean current on the floating body.

[0059] Specifically, in combination Figure 3 When the wind direction is consistent with the current direction (ocean current direction) and perpendicular to the wind turbine blades (maximum power generation efficiency), the thrust of the ocean current on the entire floating body 110 can be considered as F3 originating from its center point O and directed in the same direction as the ocean current. At this time, the wind thrust on the first wind turbine 150 (point A) is F1 (same wind direction), and the wind thrust on the second wind turbine 160 (point C) and the third wind turbine 170 (point B) is F2 (same wind direction). The mooring force F_mooring provided by the mooring cable 140 satisfies:

[0060] 2F2+F3+F1=Fmooring

[0061] There exists a torque balance around point A, ΣM A =0, that is, M A顺时针 =M A逆时针 .

[0062] Combination Figure 4 When the wind direction is inconsistent with the current direction (ocean current direction), in order to balance the rotational torque generated by the ocean current force F3, the yaw control unit needs to adjust the yaw angle of the wind turbine so that the torque generated by the wind force on the wind turbine can just offset the torque of the ocean current.

[0063] At this point, the angle between the flow direction and the wind direction is α, and the angle between the wind direction and the windward direction (perpendicular to the direction of the blades) of the second and third fans is β.

[0064] In the direction perpendicular to the wind direction: F3·sinα·=2F2·cosβ2,

[0065] Along the wind direction: 2F2·sinα+F3·cosα+F mooring

[0066] After the rotational torque generated by the ocean current force F3 is balanced by the second and third wind turbines, we have: ΣM A =0, that is:

[0067] F3·sinα·L·cos30°·2 / 3=F1·cosβ1·L·cos30°+F2·cosβ2·L·cos30°.

[0068] It should be noted that the offset angles of the second and third fans can be different. When the angles between the wind direction and the windward direction (perpendicular to the blades) of the second and third fans are β1 and β2 respectively, we have:

[0069] F3·sinα·L·cos30°·2 / 3=F1·cosβ1·L·cos30°+F2·cosβ2·L·cos30°.

[0070] Furthermore, the rotor diameter d1 of the first wind turbine and the rotor diameter d2 of the second and third wind turbines satisfy the condition: 0.35d1 < d2;

[0071] The total swept area of ​​the second and third fans is 2×0.5πd² 2 The swept area of ​​the first fan is 0.25πd1 2 satisfy:

[0072] 0.5×0.25πd1 2 <2×0.5πd2 2 <4×0.25πd1 2 .

[0073] Specifically, the total swept area of ​​the second and third fans must not be less than 50% of the swept area of ​​the large fan; otherwise, the provided wind energy will be insufficient and the torque balance cannot be effectively adjusted.

[0074] The total swept area of ​​the small fan should not exceed 100% of that of the large fan; otherwise, the small fan will be too large, increasing the weight and cost of the float and potentially interfering with the airflow field of the large fan.

[0075] Furthermore, the yaw control unit adjusts the yaw speed according to the angle α between the ocean current direction and the wind direction, specifically including:

[0076] When α ≤ 15°, the yaw speed ≤ 0.1° / second;

[0077] When 15°<α≤30°, the yaw speed ≤0.3° / second;

[0078] When 30°<α≤60°, the yaw speed ≤0.5° / second;

[0079] When α > 60°, the yaw speed is ≤ 0.7° / second.

[0080] For example, the yaw control unit selects different yaw speeds (adjusting the rotational rate of the fan direction) based on α:

[0081] When α≤15°, the yaw speed is ≤0.1° / second, indicating that the ocean current and wind direction are almost the same. At this time, the rotational torque of the floating body is small, so there is no need to frequently adjust the direction of the wind turbine, and the yaw speed can be very low, avoiding unnecessary energy consumption and mechanical wear.

[0082] When 15°<α≤30°, the yaw speed is ≤0.3° / second. At this time, the rotational torque of the ocean current on the floating body begins to be significant, and it is necessary to appropriately increase the adjustment speed of the wind turbine in order to counteract the rotational torque.

[0083] When 30°<α≤60°, the yaw speed is ≤0.5° / second. As the included angle increases further, the rotational torque brought by the ocean current is larger, and the wind turbine needs to adjust the angle more quickly to generate a suitable compensating torque to ensure the stability of the floating body.

[0084] When α > 60°, the yaw speed is ≤ 0.7° / second, indicating that the ocean current and wind direction are significantly different, and the floating body is subjected to a large rotational torque. Yaw adjustment must be accelerated to respond quickly and prevent the floating body from deflecting too much or becoming unstable.

[0085] When α is small, the system is less affected by external forces, the direction of the fan does not need to be adjusted frequently, and low-speed yaw can reduce the fatigue of mechanical components and improve the life of the fan.

[0086] When α is large, the floating body is greatly affected by the ocean current. If the yaw speed is too low, the wind turbine compensation torque cannot be adjusted in time, which may cause the floating body to deviate or even become unstable. Therefore, it is necessary to increase the yaw speed.

[0087] Optionally, if the adjustment capability of the wind turbine yaw mechanism is limited, additional inertial damping control can be added to make the adjustment process smoother and avoid large swings of the wind turbine that could cause resonance of the floating body.

[0088] Furthermore, the side length L of the equilateral triangle of the floating body and the diameter d1 of the first wind turbine rotor satisfy L≥d1.

[0089] The design constraint L≥d1 ensures the aerodynamic independence between wind turbines, improves the structural stability of the floating body, and optimizes the yaw control strategy, enabling the floating wind power system to operate more stably and efficiently in complex offshore environments.

[0090] Furthermore, the length of the mooring cable is not less than 5 times the side length of the float.

[0091] It facilitates the freedom of movement of the floating body under complex conditions of wind, waves and currents, and avoids mooring failure or cable breakage when the floating body is subjected to instantaneous impact force due to the mooring cable being too short.

[0092] Furthermore, the top of the anchoring foundation is equipped with a universal joint, which is hinged to the tension leg. The universal joint at the top of the anchoring foundation, by hinged to the tension leg, can adapt to the multidirectional swaying of the floating body caused by ocean currents and wind loads, reducing stress concentration at the anchoring point and extending the service life of the anchoring structure.

[0093] Furthermore, the yaw control unit includes wind, wave and current sensors, and the wind, wave and current sensor group includes an ultrasonic anemometer, a wave height meter and a current meter installed at the centroid of the buoy. The data of the wind, wave and current sensor group is transmitted to the yaw control unit via wired or wireless means.

[0094] The wind, wave and current sensor group of the yaw control unit uses an ultrasonic anemometer, wave height meter and current meter installed at the centroid of the floating body. Real-time data is transmitted by wire or wireless means to ensure high-precision synchronous monitoring of wind direction, wave direction and current speed. This provides a reliable basis for dynamically adjusting the yaw angle of the small wind turbine, and avoids control failure caused by signal delay or loss, especially in severe sea conditions.

[0095] In another embodiment of this disclosure, an offshore wind farm is provided, including multiple single-point moored floating wind power systems. The single-point moored floating wind power systems included in the offshore wind farm can operate independently, with cables converging at the offshore wind farm's energy storage device. Alternatively, multiple single-point moored floating wind power systems of unlimited number can share the same anchor foundation to achieve a more stable structure.

[0096] In another embodiment of this disclosure, an offshore substation is provided, which includes at least one offshore wind farm, and the stored electrical energy of the offshore wind farm is input into the power grid through a substation.

[0097] The above embodiments are only used to illustrate the technical solutions of this disclosure, and are not intended to limit it. Although this disclosure 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 of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this disclosure, and should all be included within the protection scope of this disclosure.

Claims

1. A single-point moored floating wind power system, characterized in that, The system includes: A floating body, comprising three columns, with any two columns connected in pairs to form an equilateral triangle structure with a side length of L, the floating body being used to float in seawater; Tension leg connects the bottom end of the first column of the float to the top end of the anchoring foundation, the bottom end of the anchoring foundation is fixed to the seabed, and a mooring rotor is installed at the connection point between the tension leg and the first column. The mooring rotor is connected to multiple mooring cables, and the end of the mooring cable away from the mooring rotor is fixed to the seabed. The first wind turbine is fixedly installed on the top of the first column and is used to generate electricity using wind energy. The second and third fans are fixedly installed on the top of the second and third columns of the float, respectively. The first, second and third fans transmit electrical energy through cables. The impeller diameters of the second and third fans are equal and smaller than the impeller diameter d1 of the first fan. The impeller diameters d2 of the second and third fans satisfy: 2·d2<L.

2. The system as described in claim 1, characterized in that, The system also includes a yaw control unit for controlling the windward angle of the first and second wind turbines, so that the first and second wind turbines generate a compensating torque around the mooring rotor in the plane of the floating body to counteract the rotational torque generated by the ocean current on the floating body, specifically including: Real-time acquisition of the angle α between ocean current direction and wind direction; Adjust the yaw angles β1 and β2 of the first and second fans according to the α value so that the compensating torque generated by the fans satisfies: F3·sinα·L·cos30°·2 / 3=F1·cosβ1·L·cos30°+F2·cosβ2·L·cos30°, F1 and F2 represent the wind forces experienced by the first and second wind turbines, respectively, while F3 represents the force exerted by the ocean currents on the floating body.

3. The system as described in claim 1, characterized in that, The rotor diameter d1 of the first wind turbine and the rotor diameter d2 of the second and third wind turbines satisfy the following condition: 0.35d1 < d2; The total swept area of ​​the second and third fans is 2×0.5πd² 2 The swept area of ​​the first fan is 0.25πd1 2 satisfy: 0.5×0.25πd1 2 <2×0.5πd2 2 <4×0.25πd1 2 。 4. The system as described in claim 2, characterized in that, The yaw control unit adjusts the yaw speed according to the angle α between the ocean current direction and the wind direction, specifically including: When α ≤ 15°, the yaw speed ≤ 0.1° / second; When 15°<α≤30°, the yaw speed ≤0.3° / second; When 30°<α≤60°, the yaw speed ≤0.5° / second; When α > 60°, the yaw speed is ≤ 0.7° / second.

5. The system as described in claim 1, characterized in that, The side length L of the equilateral triangle of the floating body and the diameter d1 of the first wind turbine rotor satisfy L≥d1.

6. The system as described in claim 1, characterized in that, The length of the mooring cable shall not be less than 5 times the side length of the float.

7. The system as described in claim 1, characterized in that, The top of the anchoring foundation is provided with a universal joint, which is hinged to the tension leg.

8. The system as described in claim 2, characterized in that, The yaw control unit includes wind, wave and current sensors. The wind, wave and current sensor group includes an ultrasonic anemometer, a wave height meter and a current meter installed at the centroid of the buoy. The data from the wind, wave and current sensor group is transmitted to the yaw control unit via wired or wireless transmission.

9. An offshore wind farm, characterized in that, This includes multiple single-point moored floating wind power systems as described in any one of claims 1-8.

10. A type of offshore substation, characterized in that, Includes at least one offshore wind farm as described in claim 9.

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