Floating power transmission apparatus and system

Abstract

This invention discloses a floating power transmission equipment and system. The equipment includes a floating platform, at least two wind turbines mounted on the floating platform, a multi-winding step-up transformer located within the floating platform, and multiple secondary windings of the multi-winding step-up transformer electrically connected to the output terminals of the wind turbines in a one-to-one correspondence. A high-voltage switchgear located within the floating platform is also included, with its incoming line connected to the high-voltage side of the multi-winding step-up transformer and its outgoing line used to connect to a dynamic submarine cable. The system consists of multiple of the above-mentioned devices connected in series as collection units to form collection branches. This invention reduces the number of devices and costs through highly integrated design; by utilizing multiple circuit breakers and PT / CTs within the integrated switchgear, it achieves precise fault isolation and minimizes the impact range, while ensuring the system has low-voltage, high-voltage, and combined fault ride-through capabilities, significantly improving the economy and reliability of floating offshore wind power.

Description

Technical Field

[0001] This invention relates to a floating power transmission equipment and system, belonging to the field of offshore wind power technology. Background Technology

[0002] As offshore wind power expands into deeper waters, floating offshore wind power technology has become an important direction. Currently, there are two main technical approaches for ultra-large capacity floating offshore wind power generation and transmission systems: The first option is the conventional single-unit scheme, which involves installing a high-power wind turbine on a floating foundation, along with a step-up transformer and a high-voltage switchgear set connected to a dynamic submarine cable. This scheme suffers from high cost per megawatt, the transformer's placement in the nacelle or tower base increasing the risk of cracking, and insufficient space for fault monitoring and maintenance. Its high-voltage switchgear typically only includes circuit breakers and isolating grounding switches, lacking high-voltage side voltage transformers (PTs), making it impossible to directly and accurately measure the high-voltage side voltage signal. This is detrimental to the control and protection of the turbine and transformer, and the use of a single circuit breaker for protection results in inadequate line protection functions for the wind turbine (e.g., Figures 1-3 (As shown in Figure 8).

[0003] The second option is a dual-unit scheme, where two high-power wind turbines share a single floating foundation and are installed using a V-shaped support structure. Each turbine still has its own independent step-up transformer and high-voltage switchgear. Although this scheme shares a foundation, the number of transformers and switchgear is not reduced, and it lacks integrated design, resulting in high losses, high costs, and inconvenient maintenance. Its high-voltage switchgear also suffers from problems such as the lack of a high-voltage side PT (e.g., ...). Figures 4-8 (As shown).

[0004] Furthermore, the latest national standard, "Technical Specifications for Wind Farm Connection to Power Systems Part 2: Offshore Wind Power," imposes higher requirements on the fault ride-through capabilities of wind farms, including low-voltage ride-through, high-voltage ride-through, continuous ride-through, and combined fault ride-through capabilities required when transmitting power through flexible DC transmission systems. Existing technical solutions face challenges in meeting these new requirements while simultaneously reducing costs and increasing efficiency.

[0005] Therefore, there is an urgent need for a floating offshore wind power transmission solution that can achieve high equipment integration, reduce unit costs, improve system reliability, and meet the new national standard fault ride requirements. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a highly integrated, low-cost, highly reliable floating power transmission equipment and system with complete fault ride-through capability.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a floating power transmission equipment, comprising: A floating platform; At least two wind turbine units are installed on the floating platform; A multi-winding step-up transformer is installed inside the floating platform. The multiple secondary windings of the multi-winding step-up transformer are electrically connected to the output terminals of the wind turbine and correspond one-to-one. A high-voltage switchgear is installed within the floating platform. The incoming line side of the high-voltage switchgear is connected to the high-voltage side of the multi-winding step-up transformer, and the outgoing line side is used to connect to the dynamic submarine cable.

[0008] The aforementioned power transmission equipment, the high-voltage switchgear includes at least two sets of circuit breakers integrated in a sealed air chamber. One set of the circuit breakers is used for overcurrent and short-circuit protection of the wind turbine units on the floating platform, and the remaining circuit breakers are used to realize power connection, power supply, protection and fault isolation with upstream and downstream power transmission units.

[0009] The aforementioned power transmission equipment, the high-voltage switchgear is also equipped with an isolating grounding switch, a voltage transformer and a current transformer corresponding to the circuit breaker; The primary side of the voltage transformer is connected in parallel to the main bus to measure the system voltage and provide a voltage signal for relay protection. The primary side of the current transformer is connected in series in each low-voltage side outgoing circuit and / or high-voltage side outgoing circuit of the multi-winding step-up transformer, and is used to measure the current of the corresponding circuit and provide current signals for relay protection.

[0010] The aforementioned power transmission equipment includes at least two wind turbine units, which are one or more combinations of direct-drive, semi-direct-drive, or doubly-fed wind turbine units.

[0011] The aforementioned power transmission equipment includes a multi-winding step-up transformer with a voltage level of 110kV or above and a rated capacity of not less than 100MW.

[0012] The aforementioned power transmission equipment includes an equipment compartment inside the column of the floating platform. The multi-winding step-up transformer and the high-voltage switchgear are located in the equipment compartment inside the column of the floating platform. A high-voltage slip ring is also provided in the equipment compartment for connecting the outgoing side of the high-voltage switchgear to the dynamic submarine cable. The floating platform includes multiple columns. The multi-winding step-up transformer and the high-voltage switchgear are located in an equipment compartment inside one of the columns. The equipment compartment is also equipped with a high-voltage slip ring for connecting the outgoing side of the high-voltage switchgear to the dynamic submarine cable.

[0013] A floating power transmission system, comprising: At least one of the aforementioned floating power transmission devices serves as a power collection unit; Dynamic submarine cables are used to transmit electrical energy; Each of the aforementioned power collection units is connected in series via a dynamic submarine cable on the outgoing side of its high-voltage switchgear to form a power collection branch; the high-voltage switchgear in each of the aforementioned power transmission units is electrically connected to the adjacent power transmission unit via its link circuit breaker to form the power collection line.

[0014] In the aforementioned power transmission system, the high-voltage switchgear of the collector unit located at the end of the collector branch is equipped with two sets of circuit breakers and two sets of voltage transformers. One set of voltage transformers in the high-voltage switchgear is connected in parallel to the bus section connecting the high-voltage side of the transformer, and the other set is connected in parallel to the bus section connecting the dynamic submarine cable.

[0015] In the aforementioned power transmission system, the high-voltage switchgear of the power collection unit located at other locations in the power collection branch is equipped with three sets of circuit breakers and three sets of voltage transformers. One set of voltage transformers in the high-voltage switchgear is connected in parallel to the bus section connecting the high-voltage side of the transformer, and the rest are connected in parallel to the bus section connecting the dynamic submarine cables on both sides.

[0016] In the aforementioned power transmission system, the primary side of the current transformer in the high-voltage switchgear is connected in series in the high-voltage side outgoing circuit of the multi-winding step-up transformer to measure the current of the corresponding circuit and provide a current signal for relay protection. Current transformers are also connected to each branch on the low-voltage side of the multi-winding step-up transformer. The current signal provided by the current transformer is used to realize overcurrent protection, short circuit protection and / or differential protection. The differential protection is realized by comparing the current vector sum of the high-voltage side current transformer and each low-voltage side current transformer of the multi-winding step-up transformer.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects: This invention, through the integrated design of "one base, multiple turbines, one transformer, and one switch", allows multiple wind turbines on a floating platform to share a multi-winding transformer and an integrated high-voltage switchgear, which greatly reduces the number of transformers and switchgear used, lowers equipment investment, system losses, and unit megawatt cost, while simplifying operation and maintenance.

[0018] The high-voltage switchgear of this invention adopts a multi-circuit breaker design, which includes a dedicated "link circuit breaker". When a wind turbine or a line fails within this unit, the relevant circuit breaker can quickly act to isolate the fault point, ensuring that the fault does not affect the normal operation of other wind turbines or power collection units upstream and downstream, thereby minimizing power generation losses.

[0019] The integrated high-voltage switchgear of this invention deeply integrates voltage transformers and current transformers, enabling direct and accurate measurement of high-voltage side voltage and various current signals. This provides a data foundation for implementing complex protection and control strategies, and enables the system as a whole to have low-voltage ride-through, high-voltage ride-through, continuous ride-through, and combined fault ride-through capabilities, meeting the requirements of the latest national standards.

[0020] The multi-winding transformer and high-voltage switchgear of this invention are designed for extreme compactness, high reliability and anti-vibration and anti-swaying in dynamic working conditions of floating marine environments. They can be centrally arranged in the column compartment of the floating platform, effectively solving the problem of limited space on the offshore platform and improving the environmental adaptability and safety of the equipment. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a single direct-drive floating wind turbine system in the prior art.

[0022] Figure 2 This is a schematic diagram of a single semi-direct drive floating wind turbine system in the prior art.

[0023] Figure 3 This is a schematic diagram of a single doubly fed floating wind turbine system in the existing technology.

[0024] Figure 4 This is a schematic diagram of a two-direct-drive floating wind turbine system in the prior art.

[0025] Figure 5 This is a schematic diagram of a two-semi-direct-drive floating wind turbine system in the prior art.

[0026] Figure 6 This is a schematic diagram of a two-doubly fed floating wind turbine system in the prior art.

[0027] Figure 7 This is a schematic diagram of the arrangement of two floating wind turbines and their foundation platform in the existing technology.

[0028] Figure 8 These are schematic diagrams of two existing high-voltage switchgear systems.

[0029] Figure 9 This is a schematic diagram of a floating one-base, two-machine, one-converter, one-switch system (direct drive type) in an embodiment of the present invention.

[0030] Figure 10 This is a schematic diagram of a floating one-base, two-machine, one-converter, one-switch system (semi-direct drive type) in an embodiment of the present invention.

[0031] Figure 11 This is a schematic diagram of a floating one-base, two-machine, one-transformer, one-switch system (doubly fed) in an embodiment of the present invention.

[0032] Figure 12This is a schematic diagram of a floating one-base-multiple (three-machine) one-converter-one-switch system (direct drive type) in an embodiment of the present invention.

[0033] Figure 13 This is a schematic diagram of a floating one-base-multiple (three-machine) one-converter-one-switch system (semi-direct drive type) in an embodiment of the present invention.

[0034] Figure 14 This is a schematic diagram of a floating one-base-multiple-machine (three-machine) one-transformer-one-switch system (doubly fed) in an embodiment of the present invention.

[0035] Figure 15 This is a schematic diagram of the power collection circuit based on a one-base two-machine unit in an embodiment of the present invention.

[0036] Figure 16 This is a schematic diagram of the power collection line based on a single base unit and multiple machines in an embodiment of the present invention.

[0037] Figure 17 This is a schematic diagram of the arrangement of the one-base-multiple-machine-one-transformer-one-switchgear device of the present invention on a floating platform.

[0038] Figure 18 This is a schematic diagram of the windings of the multi-winding step-up transformer of the present invention.

[0039] Figure 19 This is a schematic diagram of the internal system of the high-voltage switchgear of the present invention.

[0040] Attached reference numerals: 1-Floating platform, 101-Column, 102-Equipment compartment, 2-Wind turbine, 3-Multi-winding step-up transformer, 4-High-voltage switchgear, 5-Dynamic submarine cable, 6-High-voltage slip ring.

[0041] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Detailed Implementation

[0042] Embodiment 1 of the present invention: A floating power transmission device, comprising: A floating platform 1 serves as the foundational support structure for the entire equipment, and adopts a multi-column semi-submersible or barge-type design. In this embodiment, as... Figure 17 As shown, the platform has four columns 101, which are connected by horizontal and diagonal braces to form a stable triangular or quadrilateral floating structure capable of withstanding complex sea conditions in the deep ocean. The tops of several columns 101 are designed to support wind turbine generators, while the interior of one column 101 is constructed as one or more layered equipment compartments 102. These equipment compartments are waterproof, corrosion-resistant, and structurally reinforced, and are used to centrally house core electrical equipment. At least two wind turbine units 2 are mounted on the floating platform 1 and installed on the top of the support column 101. The wind turbine units 2 can all be direct-drive, semi-direct-drive, or doubly-fed, or a combination of these two different types. Furthermore, the rated capacity of each wind turbine unit 2 can be the same or different; this invention does not impose such limitations, reflecting design flexibility.

[0043] A multi-winding step-up transformer 3 is installed within the floating platform 1. Multiple secondary windings of the multi-winding step-up transformer 3 are electrically connected to the output terminals of the wind turbine units 2, with each winding corresponding to the previous one. The multi-winding step-up transformer 3 is installed within the equipment compartment 102 of the support column 101. The multi-winding step-up transformer 3 has one high-voltage side winding (primary winding) and multiple independent low-voltage side windings (secondary windings). The low-voltage side windings are connected to the output terminals of the full-power frequency converters or doubly-fed frequency converters at the outlets of each wind turbine unit 2 via medium-voltage cables. Its design voltage level is 110kV or higher, and the rated capacity of a single unit is not less than 100MW, sufficient to collect and boost the output of two large-capacity wind turbines. Its energy efficiency meets the national first-class standard and uses environmentally friendly insulating oil. Its structural design adopts an extremely compact design, with a volume and weight significantly smaller than the sum of two independent transformers. Its internal structure, fasteners and heat dissipation system have all been specially designed to withstand the heave, sway, tilt, vibration and acceleration impact unique to the marine environment for a long time, meeting the dynamic operating conditions requirements of floating platforms.

[0044] A high-voltage switchgear 4 is installed within the floating platform 1. The incoming line side of the high-voltage switchgear 4 is connected to the high-voltage side of the multi-winding step-up transformer 3, and the outgoing line side is used to connect to the dynamic submarine cable 5. The high-voltage switchgear 4 is also installed in the equipment compartment 102 of the support column 101, arranged adjacent to the multi-winding step-up transformer 3, and the two are connected by a short busbar. The high-voltage switchgear 4 is a sealed, air-filled metal shell with good airtightness, corrosion resistance, and mechanical strength to adapt to the high humidity and high salt spray environment at sea and the platform's movement. Its internal integrated components include... Figure 19 As shown, it integrates the following key components: Circuit breakers: at least two sets, one set as the main protection circuit breaker for the two wind turbines on this platform, responsible for their overcurrent, short circuit and other protection; the other set as a link circuit breaker, whose outgoing terminal is connected to the high-voltage slip ring 6 for connection to the collector line.

[0045] Isolating grounding switch: at least two sets, each matched with a circuit breaker, for electrical isolation and maintenance grounding.

[0046] Voltage transformers (PTs): at least two sets, one of which is connected in parallel on the primary side of the transformer high-voltage busbar for accurate measurement of the stepped-up voltage; the other voltage transformers are connected in parallel on the primary side of the link circuit breaker outgoing line, i.e., the busbar connecting the dynamic submarine cable 5, for monitoring the collector line voltage. The voltage transformer signal is a key input for achieving low-voltage ride-through and high-voltage ride-through functions.

[0047] Current transformers (CTs): At least two sets are required. One set is connected in series in the high-voltage side outgoing circuit of the transformer to monitor the total output current. The other current transformers are connected in series in the low-voltage side feeders of the transformers corresponding to the wind turbines to monitor the output of each wind turbine. These CT signals are used for current protection, power calculation, and differential protection. Differential protection determines internal transformer faults by comparing the vector sum of the high- and low-voltage side CT currents.

[0048] All the above components are connected via an internal busbar and connected to an integrated intelligent protection and control unit. This unit executes protection algorithms (overcurrent, differential, directional protection, etc.), control strategies (fault ride-through control), and network reconfiguration logic (controlling link circuit breakers to achieve fault isolation) based on real-time voltage and current signals provided by PT and CT.

[0049] Inside equipment compartment 102, the output side of the link circuit breaker of high-voltage switchgear 4 is connected to the dynamic submarine cable 5 via a high-voltage slip ring 6. The high-voltage slip ring 6 is used to solve the relative motion problem between the floating platform and the fixed submarine cable, ensuring continuous and reliable power transmission. The dynamic submarine cable 5 is responsible for transmitting the power generated by this equipment.

[0050] Embodiment 2 of the present invention: A floating power transmission system, comprising: At least one of the aforementioned floating power transmission devices serves as a power collection unit, with each unit being a floating power transmission device as described above. As an independently operable module, it internally collects, boosts, and provides preliminary protection for the electrical energy from multiple wind turbine units. The outgoing lines of its high-voltage switchgear 4 are not directly fixedly connected, but rather have a reserved interface through a "link circuit breaker" within the cabinet. This design allows each unit to operate independently or be flexibly connected in series with the dynamic submarine cable 5 as "building blocks."

[0051] Each current collection unit is connected in series via a dynamic submarine cable 5 through the outgoing side of its high-voltage switchgear 4, forming a current collection branch. The high-voltage switchgear 4 in each transmission unit is electrically connected to the adjacent transmission unit via its link circuit breaker, forming a current collection line. Specifically, the dynamic submarine cable 5 is led out from the outgoing side of the high-voltage switchgear 4 of the upstream unit (i.e., the lower end of its "link circuit breaker") and connected to the incoming busbar of the high-voltage switchgear 4 of the downstream unit (usually through its other "link circuit breaker"). This series connection forms a chain structure. Within each unit's high-voltage switchgear 4, at least one circuit breaker is designated as a "link circuit breaker." Its function is to close under normal conditions, conducting the current collection; and to quickly trip upon receiving a protection command, achieving electrical isolation. The terminal unit requires only one link circuit breaker to connect to the upstream, while intermediate units require two link circuit breakers to connect the upstream and downstream respectively.

[0052] To ensure measurable and controllable voltage across the entire line, units located in the middle of the collector branch are equipped with three sets of voltage transformers (PTs) in their high-voltage switchgear. These PTs monitor: the bus voltage connected to the high-voltage side of the transformer in this unit; the incoming voltage connected to the upstream submarine cable; and the outgoing voltage connected to the downstream submarine cable. Units located at the very end of the branch are equipped with two sets of PTs, monitoring the transformer-side voltage and the upstream incoming voltage, respectively. This configuration is fundamental to achieving accurate fault location and coordinated voltage ride-through control. Each collector branch ends via a dynamic submarine cable 5, ultimately connecting to an offshore booster station or offshore converter station. Within the booster station / converter station, a high-voltage switchgear is installed to receive electrical energy from each collector branch and perform further voltage conversion or DC-DC conversion before feeding it into the main power grid.

[0053] Embodiment 3 of the present invention: A floating one-base, two-machine, one-transformer, one-switch power generation and transmission equipment and system A floating power generation and transmission system consisting of one base, two turbines, one transformer, and one switchgear, employs one or more combinations of direct-drive floating wind turbines, semi-direct-drive floating wind turbines, and doubly-fed floating wind turbines, wherein: like Figure 9 As shown, a direct-drive floating wind turbine is used, including blades, a permanent magnet generator, a full-power frequency converter, a floating platform 1, a multi-winding step-up transformer 3, and a high-voltage switchgear 4. like Figure 10 As shown, a semi-direct drive floating wind turbine is adopted, including blades, gearbox, permanent magnet generator, full-power frequency converter, floating platform 1, multi-winding step-up transformer 3 and high-voltage switchgear 4; Figure 11 As shown, a doubly fed floating wind turbine is used, including blades, gearbox, doubly fed generator, frequency converter, floating platform 1, multi-winding step-up transformer 3 and high-voltage switchgear 4.

[0054] The two floating wind turbines share a floating platform 1. The two floating wind turbines 2 on the floating platform 1 can be of the same or different types and have the same or different capacities.

[0055] The multi-winding step-up transformer 3 within the floating platform 1 is a floating three-winding step-up transformer with a Class 1 energy efficiency rating and an extremely compact design. The high-voltage switchgear 4 within the floating platform 1 includes at least two circuit breakers, two isolating grounding switches, two voltage transformers (PTs), and three current transformers (CTs), all integrated within a sealed chamber. This high-voltage switchgear features a "dual circuit breaker" design, deep integration and collaborative innovation of "high-voltage PTs and CTs," and a compact shared enclosure design, integrating protection, control, measurement, monitoring, and network reconfiguration functions.

[0056] A floating, single-base, two-machine, one-transformer, one-switch power generation and transmission system, such as Figure 15 As shown, in this embodiment, the above-mentioned floating one-base two-machine one-transformer-one-switch power transmission equipment is designed as a unit for the collection line design. Multiple units form a collection line, which is connected to the high-voltage switchgear of the offshore booster station / offshore converter station through dynamic submarine cable 5.

[0057] The high-voltage switchgear 4 of the terminal unit is equipped with 3 sets of circuit breakers and 2 sets of voltage transformers (PTs). The high-voltage switchgear 4 of other unit units is equipped with 3 circuit breakers and 3 voltage transformers (PTs).

[0058] One circuit breaker is responsible for overcurrent and short-circuit protection of the wind turbines on this floating platform. The remaining circuit breakers act as "link circuit breakers," responsible for connection, power supply, protection, and fault isolation with upstream and downstream wind turbines. Faults in the wind turbines on this platform will not affect the normal operation of upstream and downstream wind turbines. Faults in the transmission lines will only affect the operation of wind turbines downstream of this line.

[0059] Embodiment 4 of the present invention: A floating single-base multi-machine single-transformer single-switch power generation and transmission equipment and system A floating, single-base, multi-machine, single-transformer, single-switchgear power generation and transmission system employs one or more combinations of direct-drive floating wind turbines, semi-direct-drive floating wind turbines, and doubly-fed floating wind turbines, wherein: like Figure 12 As shown, a direct-drive floating wind turbine is used, including blades, a permanent magnet generator, a full-power frequency converter, a floating platform 1, a multi-winding step-up transformer 3, and a high-voltage switchgear 4. like Figure 13 As shown, a semi-direct drive floating wind turbine is adopted, including blades, gearbox, permanent magnet generator, full-power frequency converter, floating platform 1, multi-winding step-up transformer 3 and high-voltage switchgear 4; Figure 14As shown, a doubly fed floating wind turbine is used, including blades, gearbox, doubly fed generator, frequency converter, floating platform 1, multi-winding step-up transformer 3 and high-voltage switchgear 4.

[0060] The equipment consists of three floating wind turbine units 2 sharing a floating platform 1. These three turbine units can be of the same or different types and capacities. The multi-winding step-up transformer 3 on the floating platform 1 is a floating four-winding step-up transformer with a Class 1 energy efficiency rating and an extremely compact design. The high-voltage switchgear 4 within the floating platform 1 includes at least three circuit breakers, three isolating grounding switches, three voltage transformers (PTs), and three current transformers (CTs), all integrated within a sealed air chamber.

[0061] This high-voltage switchgear features a multi-circuit breaker design, deep integration and collaborative innovation of high-voltage PT and CT, and a compact shared enclosure design, integrating protection, control, measurement, monitoring and network reconfiguration functions.

[0062] A floating, single-base, multi-machine, single-transformer, single-switch power generation and transmission system, such as Figure 16 As shown, in this embodiment, the above-mentioned floating one-base-multiple-machine-one-transformer-one-switch is designed as a unit for the power collection line. Multiple units form a power collection line that is connected to the high-voltage switchgear of the offshore booster station / offshore converter station through a dynamic submarine cable 5.

[0063] The "floating one-base-multiple-machine-one-transformer-one-switch" unit in this collector line includes both entirely floating one-base-multiple-machine-one-transformer-one-switch units, and combinations of floating one-base-two-machine-one-transformer-one-switch units and floating one-base-multiple-machine-one-transformer-one-switch units. The high-voltage switchgear 4 of the terminal unit is equipped with 3 sets of circuit breakers and 3 sets of voltage transformers (PTs), while the high-voltage switchgear 4 of other unit units is equipped with 3 sets of circuit breakers and 3 sets of voltage transformers (PTs).

[0064] One circuit breaker is responsible for overcurrent and short-circuit protection of the wind turbines on this floating platform. The remaining circuit breakers act as "link circuit breakers," responsible for connection, power supply, protection, and fault isolation with upstream and downstream wind turbines. Faults in the wind turbines on this platform do not affect the normal operation of upstream and downstream wind turbines. Faults in the lines only affect the operation of wind turbines downstream of this line.

[0065] In the above embodiments, the layout of the equipment consisting of one base station, multiple generators, one transformer, and one switch is as follows: Figure 17As shown: The multiple floating wind turbines 2 on this floating foundation can be of the same or different types, with the same or different capacities. The high-voltage transformer 3 inside the floating platform is a floating multi-winding step-up transformer with a first-class energy efficiency rating, a design voltage level of 110kV and above, and a single unit design rated capacity not limited to 100MW and above. It uses environmentally friendly insulating oil and features an extremely compact design.

[0066] The high-voltage switchgear within the floating platform includes, but is not limited to, at least two circuit breakers, two isolating grounding switches, two voltage transformers (PTs), and three current transformers (CTs), all integrated within a sealed chamber. This high-voltage switchgear features a "dual circuit breaker" or "multiple circuit breaker" design, deep integration and collaborative innovation of "high-voltage PTs and CTs," and a compact shared enclosure design, integrating protection, control, measurement, monitoring, and network reconfiguration functions. The high-voltage transformer, high-voltage switchgear, and high-voltage slip rings are housed within the equipment compartment of the floating platform's columns, allowing for compact, same-level or layered arrangement while ensuring safety and ease of maintenance.

[0067] In the above embodiments, the high-voltage transformer 3 is as follows: Figure 18 As shown, considering the operational conditions, equipment layout space constraints, and cost limitations of large-capacity floating offshore platforms, this high-voltage transformer 3 incorporates a new Level 1 energy efficiency rating and features an extremely compact design. This results in low losses, small size, light weight, convenient operation and maintenance, high reliability, and the ability to be placed on a platform within a tower or floating foundation. This floating transformer meets requirements for dynamic motion, acceleration, heave, swaying, tilting, and vibration, and possesses low-voltage ride-through, high-voltage ride-through, continuous ride-through, newly added combined fault ride-through capabilities, and typhoon resistance.

[0068] The secondary winding capacity of this floating transformer is not limited to whether they are of the same capacity, and they are connected to the corresponding wind turbine units respectively. This achieves innovative design, high energy efficiency, high reliability, environmental protection, reduced overall system losses, and improved cost per kilowatt-hour requirements.

[0069] In the above embodiments, the high-voltage switchgear 4 is as follows: Figure 19As shown, considering the operational conditions and space constraints of large-capacity floating offshore platforms, this high-voltage switchgear is designed for voltage levels of 110kV and above. It features an extremely compact design and special sealing treatment, achieving small size, light weight, and convenient operation and maintenance. It can be placed on platforms within towers or floating foundations. This high-voltage switchgear meets requirements for heave, swaying, tilting, and vibration, and possesses low-voltage ride-through, high-voltage ride-through, continuous ride-through, newly added joint fault ride-through functions, and typhoon resistance. The switchgear innovatively incorporates a "dual circuit breaker" or "three (multiple) circuit breaker" design, deep integration and collaborative innovation of "high-voltage PT and CT," and a compact shared enclosure design. This high-voltage switchgear integrates protection, control, measurement, monitoring, and network reconfiguration functions, enabling flexible network construction and flexible operation and maintenance, minimizing power generation losses. This high-voltage switchgear integrates multiple circuit breakers, multiple PT / CTs, isolating grounding switches, and their complex interlocking logic into a single, minimally sized airtight enclosure, achieving significant challenges and innovations in mechanical and electrical design. The dual or multi-circuit breaker design ensures that upstream and downstream wind turbines are not affected in the event of a fault, thus minimizing the impact and reducing power generation losses. Deep integration of high-voltage PTs and CTs provides a basis for complex protection strategies, empowers advanced condition monitoring and data analysis, and enables synchronous phasor measurement, providing a revolutionary and innovative technology for the stable operation of floating offshore wind farms.

[0070] The working principle of one embodiment of the present invention: At the equipment level, this invention involves multiple wind turbines installed on the same floating platform. The electricity generated is first collected by a multi-winding step-up transformer inside the platform cabin. This transformer steps up the medium-voltage electricity of each turbine to 110kV and above, achieving a high degree of integration at the equipment level and fundamentally reducing the cost per unit capacity. The integrated high-voltage switchgear deeply integrates multiple circuit breakers, voltage transformers (PTs), and current transformers (CTs). The PTs continuously and accurately monitor the high-voltage bus voltage, and the CTs accurately measure the current of each branch and the total output current. Based on these real-time signals, the system's embedded protection control unit can execute complex logic. A multi-circuit breaker design is adopted, with one set serving as the "protective circuit breaker" for the wind turbine in this unit, and the rest serving as "link circuit breakers" connecting upstream and downstream units.

[0071] At the system level, multiple such units are connected in series via dynamic submarine cables to form a power collection branch. When a fault occurs within any unit, only its own "protective circuit breaker" trips, strictly confining the fault to that unit. Through the conduction of its "link circuit breaker," continuous power supply is ensured to all other upstream and downstream units, minimizing the impact of the fault. When a fault occurs in the connecting submarine cable, the "link circuit breakers" of the units on both sides of the fault point can trip simultaneously, precisely isolating the faulty segment and affecting only the downstream units in that segment, maximizing the preservation of power generation. This invention discloses a floating power transmission equipment and system. The equipment includes a floating platform, at least two wind turbines mounted on the floating platform, a multi-winding step-up transformer located within the floating platform, and multiple secondary windings of the multi-winding step-up transformer electrically connected to the output terminals of the wind turbines in a one-to-one correspondence. A high-voltage switchgear located within the floating platform is also included, with its incoming line connected to the high-voltage side of the multi-winding step-up transformer and its outgoing line used to connect to a dynamic submarine cable. The system consists of multiple of the above-mentioned devices connected in series as collection units to form collection branches. This invention reduces the number of devices and costs through highly integrated design; by utilizing multiple circuit breakers and PT / CTs within the integrated switchgear, it achieves precise fault isolation and minimizes the impact range, while ensuring the system has low-voltage, high-voltage, and combined fault ride-through capabilities, significantly improving the economy and reliability of floating offshore wind power.

Claims

1. A floating power transmission device, characterized in that, include: A floating platform (1); At least two wind turbine units (2) are installed on the floating platform (1); A multi-winding step-up transformer (3) is installed within the floating platform (1), and the multi-winding step-up transformer (3) has... Multiple secondary windings are electrically connected to the output terminals of the wind turbine (2) and correspond one-to-one; A high-voltage switchgear (4) is installed inside the floating platform (1), the incoming line side of the high-voltage switchgear (4) being connected to the... The high-voltage side of the multi-winding step-up transformer (3) is connected, and the outgoing side is used to connect the dynamic submarine cable (5).

2. The floating power transmission equipment according to claim 1, characterized in that, The high-voltage switchgear (4) includes a collection At least two circuit breakers are installed in a sealed air chamber, one of which is used for ventilation on the floating platform (1). The overcurrent and short-circuit protection of the generator set (2) is provided, and the remaining circuit breakers are used to realize the power connection with the upstream and downstream power transmission units and supply power. Electrical, protection and fault isolation.

3. A floating power transmission equipment according to claim 2, characterized in that, The high-voltage switchgear (4) is also equipped with It is equipped with an isolating grounding switch, a voltage transformer, and a current transformer corresponding to the circuit breaker; The primary side of the voltage transformer is connected in parallel to the main bus to measure the system voltage and provide a voltage signal for relay protection. The primary side of the current transformer is connected in series with each low-voltage side output circuit of the multi-winding step-up transformer and / or In the high-voltage side outgoing circuit, it is used to measure the current of the corresponding circuit and provide current signals for relay protection.

4. A floating power transmission device according to claim 3, characterized in that, The at least two wind turbine units (2) It is one or more combinations of direct-drive, semi-direct-drive, or doubly-fed wind turbine units.

5. A floating power transmission equipment according to claim 3, characterized in that, The multi-winding step-up transformer (3) The voltage level is 110kV and above, and the rated capacity is not less than 100MW.

6. A floating power transmission equipment according to claim 3, characterized in that, The columns of the floating platform (1) The unit is equipped with an equipment compartment, and the multi-winding step-up transformer (3) and the high-voltage switchgear (4) are located on the floating platform. Inside the equipment compartment of the column (1), a high-pressure slip ring 6 is also installed to connect the column. The outgoing side of the high-voltage switchgear (4) is connected to the dynamic submarine cable (5). The floating platform (1) includes multiple columns (101), the multi-winding step-up transformer (3), and the high-voltage switchgear (4). The equipment compartment (102) is located inside one of the columns (101), and the equipment compartment (102) is also equipped with There is a high-voltage slip ring 6, which is used to connect the outgoing side of the high-voltage switchgear (4) to the dynamic submarine cable (5).

7. A floating power transmission system, characterized in that, include: At least one floating power transmission device as described in any one of claims 1 to 6, serving as a power collection unit; Dynamic submarine cable (5) is used to transmit electrical energy; Each of the aforementioned current collection units is connected in series via a dynamic submarine cable (5) on the outgoing side of its high-voltage switchgear (4), forming a... Each transmission unit has a power collection branch; the high-voltage switchgear (4) in each of the transmission units is connected to the adjacent transmission unit via its link circuit breaker. The gas connection forms the current collector circuit.

8. A floating power transmission system according to claim 7, characterized in that, The collector located at the very end of the collector branch The high-voltage switchgear (4) of the electrical unit is equipped with two sets of circuit breakers and two sets of voltage transformers. One set of voltage transformers is connected in parallel to the busbar section connecting the high-voltage side of the transformer, and the other set is connected in parallel to the busbar section connecting the dynamic submarine cable. Line segment.

9. A floating power transmission system according to claim 8, characterized in that, Located at other locations in the collector branch The high-voltage switchgear of the current collector unit is equipped with three sets of circuit breakers and three sets of voltage transformers. The high-voltage switchgear (4) contains one... The voltage transformers are connected in parallel to the busbar section on the high-voltage side of the transformer, and the rest are connected in parallel to the busbars of the dynamic submarine cables connecting both sides. Line segment.

10. A floating power transmission system according to claim 8, characterized in that, The high-voltage switchgear (4) inside The primary side of the current transformer is connected in series in the high-voltage side outgoing circuit of the multi-winding step-up transformer for measuring phase current. It should provide the current in the circuit and supply the current signal for the relay protection; Current transformers are also connected to each branch on the low-voltage side of the multi-winding step-up transformer. The current signal provided by the current transformer is used to implement overcurrent protection, short-circuit protection, and / or differential protection. The differential protection... The actual measurement is achieved by comparing the current vector sum of the high-voltage side current transformer and each low-voltage side current transformer of the multi-winding step-up transformer. now.

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