Offshore converter station

Abstract

The present invention discloses an offshore converter station, comprising a top station layer and a bottom station layer arranged in layers along the height direction. The bottom station layer is equipped with a valve hall and a DC field. The valve hall is equipped with a first power distribution device and a diode converter valve with a quadruple valve structure. The DC field is equipped with a second power distribution device and a smoothing reactor. The top station layer is equipped with an AC field, which is equipped with a third power distribution device and a converter transformer. A cable room is provided between the top and bottom stations, in which cables are arranged. The third power distribution device is connected to an AC submarine cable, the third power distribution device is connected to the converter transformer via a cable, the converter transformer is connected to the valve hall via a cable, and the valve hall is connected to the DC field via a cable. The smoothing reactor is arranged on the DC pole line of the diode converter valve, and the first power distribution device of the DC field uses a cable outlet. The present invention can be applied to offshore DC transmission systems with voltages reaching ±500kV and above and capacities reaching 2000MW and above.

Description

Technical Field

[0001] The present invention is used in the fields of offshore wind power and direct current transmission, and particularly relates to an offshore converter station. Background Art

[0002] Large-capacity offshore converter stations specifically refer to those with a rated capacity of 2000MW or above and a DC voltage level of ±500kV or above. Existing offshore converter station solutions include ±250kV / 1000MW, ±320kV / 1000MW, and ±400kV / 1000MW. These systems have lower capacities than 2000MW systems, with smaller equipment counts, dimensions, and weight. Furthermore, their system overvoltage insulation levels and air clearances are lower than those of ±500kV systems, requiring smaller equipment layout dimensions. Consequently, their electrical process layout methods are unsuitable for large-capacity offshore converter stations of 2000MW or above.

[0003] For example, in the patent application document with publication number CN112510745A, the invention provides a flexible DC offshore converter station connected to a 66kV collector line. The main problems with this technology are:

[0004] 1) This technical solution is only applicable to offshore converter stations with small capacity (approximately 1000MW). It is not applicable to offshore converter stations with large capacity (2000MW and above) because the number of electrical equipment and the distance between equipment increase with the increase of capacity and voltage, which in turn increases the number and size of rooms. Therefore, all rooms in the entire steel structure building need to be reorganized and rearranged.

[0005] 2) This invention is a flexible DC converter valve based on a modular multi-level converter. The flexible DC converter valve is divided into three-phase upper and lower bridge arms, with a total of six bridge arms. In existing engineering applications, the number of power modules in each bridge arm is proportional to the DC voltage. For example, the number of power modules in a single bridge arm with a DC voltage level of ±320kV is not less than 320 (including redundancy), and the number of power modules in a single bridge arm with a DC voltage level of ±400kV is not less than 400 (including redundancy). For large-capacity (2000MW and above) offshore converter stations, the DC voltage level needs to be ±500kV, and the number of power modules in each bridge arm will reach 500 (including redundancy). The body size, floor space and weight of the converter valve will be much larger than that of this invention (1000MW level). The valve hall and converter valve of this invention are far from being able to be arranged, and the entire platform needs to be reorganized and arranged.

[0006] 3) This invention uses a symmetrical monopole system. If any pole or a single converter valve fails or undergoes maintenance, the entire system will shut down, resulting in a complete loss of transmission power. This reduces system reliability and the availability of offshore converter stations.

[0007] 4) The converter valve of this invention is a flexible DC converter valve based on a modular multilevel converter. The flexible DC converter valve is a supported structure with a high center of gravity in the valve tower, which negatively impacts the equipment's seismic performance. A single valve tower weighs 80 to 100 tons, and the flatness of the mounting surface of the base of each valve tower is highly demanding. This increases the structural strength and deflection requirements of the platform, hindering overall weight reduction. Summary of the Invention

[0008] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art and to provide an offshore converter station.

[0009] The technical solution adopted by the present invention to solve its technical problem is:

[0010] An offshore converter station comprises a top station layer and a bottom station layer arranged in layers along the height direction, the bottom station layer being provided with a valve hall and a DC field, the valve hall being provided with a first power distribution device and a diode converter valve connected to the first power distribution device, the diode converter valve adopting a quadruple valve structure, the DC field being provided with a second power distribution device and a smoothing reactor connected to the second power distribution device, the top station layer being provided with an AC field, the AC field being provided with a third power distribution device and a converter transformer, a cable room being provided between the top station layer and the bottom station layer, the cable room being provided with cables for connecting equipment in the top and bottom station layers, the third power distribution device being connected to an external AC submarine cable, the third power distribution device being connected to the converter transformer via a cable, the converter transformer being connected to the valve hall via a cable, the valve hall being connected to the DC field via a cable, the smoothing reactor being arranged on the DC pole line of the diode converter valve, and the first power distribution device of the DC field adopts a cable outlet.

[0011] In combination with the above implementation methods, in some implementation methods, two sets of the first distribution devices and diode converter valves are symmetrically arranged in the valve hall, two sets of the second distribution devices and smoothing reactors are symmetrically arranged in the DC field, and two sets of the third distribution devices and converter transformers are symmetrically arranged in the AC field.

[0012] In combination with the above implementations, in certain implementations, the diode converter valve is suspended and installed in the valve hall.

[0013] In combination with the above implementations, in some implementations, the Y-connected AC incoming line and the △-connected AC incoming line of the diode converter valve are respectively arranged on both sides of the diode converter valve, the DC busbar of the diode converter valve is arranged between phases perpendicular to the incoming line direction, and the positive DC outgoing line and the negative DC outgoing line of the diode converter valve are led out from the phases.

[0014] In combination with the above implementations, in some implementations, the DC field and the valve hall are arranged adjacent to each other on the same floor, the DC field and the valve hall are electrically connected using a DC wall bushing, and an inspection hole is reserved directly above the smoothing reactor.

[0015] In combination with the above implementations, in some implementations, the second power distribution device uses a DC GIS device.

[0016] In combination with the above implementations, in some implementations, the third power distribution device adopts AC GIS equipment above 66kV, and the third power distribution device is arranged in a straight line above the valve hall. A cable shaft for laying AC submarine cables is arranged on the side of the third power distribution device.

[0017] In combination with the above implementation methods, in some implementation methods, a STATCOM device is also provided in the AC field, and an inspection hole is reserved directly above the STATCOM device. The third distribution device, the converter transformer and the STATCOM device are arranged on the same floor. The third distribution device is connected to the converter transformer with a cable. The cable enters the cable room from the cable shaft. A hole is opened on the ground of the converter transformer room, and the cable enters the converter transformer room from the cable room below. The third distribution device is connected to the STATCOM device with a cable. A hole is opened on the ground of the STATCOM device room, and the cable enters the STATCOM device room from the cable room below.

[0018] In combination with the above implementations, in some implementations, a relay room is provided on the top station floor, the relay room and the AC field are arranged on the same floor, and the relay room is located at the center of the third distribution device, converter transformer, and STATCOM equipment.

[0019] In combination with the above implementation methods, in some implementation methods, a transformer oil collection tank room and an auxiliary room are provided in the cable room, the transformer oil collection tank room is arranged below the converter transformer, a partition is provided on the top of the top station layer, a station power room is provided in the partition, and a circular corridor is arranged along the periphery of the rooms on each floor.

[0020] One of the above technical solutions has at least one of the following advantages or beneficial effects:

[0021] The present invention can be applied to offshore DC transmission systems with voltages of ±500kV and above and capacities of 2000MW and above. By comprehensively considering the layout requirements of functional rooms and auxiliary rooms, rooms with larger layout sizes and more open equipment, such as valve halls and DC fields, are arranged at the lower part of the platform, and AC fields are arranged at the upper part of the platform. A cable room is arranged between the upper and lower parts of the platform, thereby improving the space utilization of the platform and making the overall platform layout more compact. At the same time, a dedicated cable layer is planned, which not only ensures smooth electrical connections between various devices, but also minimizes the platform size and saves steel.

[0022] The present invention uses a diode converter valve with a quadruple valve structure. The valve tower is much smaller and lighter than a modular multi-level converter valve, which can reduce the size of the valve hall and thus the size and weight of the platform.

[0023] This invention uses diode valves and uncontrolled rectification. These valves have significantly lower operating losses than modular multi-level valves, reducing the requirements for auxiliary equipment such as cooling units and air conditioning units, reducing the size and weight of the auxiliary equipment room, and ultimately the size and weight of the platform.

[0024] The application example of the present invention can reduce the platform unit capacity weight by more than 40% compared with the existing offshore converter station, and reduce the platform size by more than 15% compared with the existing offshore converter station.

[0025] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0027] Figure 1 It is a cross-sectional view of an embodiment of the present invention;

[0028] Figure 2 yes Figure 1 Middle AA layout drawing;

[0029] Figure 3 yes Figure 1 Middle BB layout diagram;

[0030] Figure 4 yes Figure 1 CC layout drawing;

[0031] Figure 5 yes Figure 1 Medium DD layout drawing;

[0032] Figure 6 yes Figure 1 EE layout drawing;

[0033] Figure 7 This is a process flow diagram of an embodiment of the present invention;

[0034] Figure 8 This is a schematic diagram of conductor connections in each room according to an embodiment of the present invention;

[0035] Figure 9 It is a schematic diagram of the valve tower wiring and layout according to one embodiment of the present invention. DETAILED DESCRIPTION

[0036] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it should not be understood as a limitation on the scope of protection of the present invention.

[0037] In the present invention, if directions (up, down, left, right, front and back) are described, it is only for the convenience of describing the technical solution of the present invention, and does not indicate or imply that the technical features referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, it cannot be understood as a limitation of the present invention.

[0038] In the present invention, "several" means one or more, "multiple" means more than two, "greater than," "less than," "exceeds," etc. are understood to exclude the number itself; "above," "below," "within," etc. are understood to include the number itself. In the description of the present invention, the use of "first" or "second" is solely for the purpose of distinguishing technical features and is not to be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0039] In the present invention, unless otherwise expressly defined, terms such as "disposed," "installed," and "connected" should be interpreted broadly. For example, they may refer to direct connection or indirect connection through an intermediate medium; fixed connection or detachable connection or integral molding; mechanical connection or electrical connection or mutual communication; and internal connection between two components or interaction between two components. Those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0040] in, Figure 1 The reference direction of the embodiment of the present invention is given below. Figure 1 The embodiment of the present invention is described with reference to the direction shown.

[0041] See also Figures 1-8An embodiment of the present invention provides an offshore converter station comprising a top and bottom station layers arranged in layers along the vertical direction. The bottom station layer houses a valve hall 100 and a DC field 200. The valve hall 100 houses a first power distribution device 120 and a diode converter valve 110 connected to the first power distribution device 120. A single converter valve maintenance unit weighs less than 1 ton, so it is considered to be located at the lower end of the platform. The diode converter valve 110 utilizes a quadruple valve structure, concentrating the upper and lower bridge arms of the converter unit on a single valve tower. A single-pole converter valve requires only three valve towers, while a modular multilevel converter valve of the same voltage and capacity requires six to nine valve towers (as shown in other inventions). Therefore, the size and weight of the diode converter valve 110 are significantly smaller than those of the modular multilevel converter valve, and the size of the valve hall 100 is also optimized.

[0042] A second power distribution device 220 and a smoothing reactor 210 connected to the second power distribution device 220 are provided in the DC field 200. The DC transmission system based on the diode converter valve 110 solution only has the smoothing reactor 210 and does not require a bridge arm reactor. The smoothing reactor 210 is arranged on the DC pole line of the diode converter valve 110 to suppress the characteristic harmonics generated on the DC side by uncontrolled rectification.

[0043] An AC field 300 is provided at the top station layer, in which a third distribution device 310 and a converter transformer 320 are provided. A cable room 500 is provided between the top station layer and the bottom station layer, in which cables for connecting the equipment in the top station layer and the bottom station layer are arranged. The third distribution device 310 is externally connected to an AC submarine cable, and the third distribution device 310 is connected to the converter transformer 320 via a cable. The converter transformer 320 is connected to the valve hall 100 via a cable, and the valve hall 100 is connected to the DC field 200 via a cable. The first distribution device 120 of the DC field 200 uses a cable outlet.

[0044] For details, see Figure 7 、 Figure 8 There are 30 or more AC submarine cables. In order to facilitate the laying of cables on the platform, the submarine cables pass through the J-shaped tube onto the platform, go from the cable shaft to the cable room 500, and then connect to the third distribution device 310 from below.

[0045] In the present invention, the converter transformer incoming line loop cable of the third power distribution device 310 passes through the cable shaft to the cable room 500 and is connected to the converter transformer 320.

[0046] In the present invention, cables are used as the connecting conductors between the converter transformer 320 and the valve hall 100. Cables are flexible conductors with good adaptability to platform deformation and deflection. They are also easy to install, requiring minimal space for cable laying via a cable winch. Furthermore, cables are oil- and gas-free, requiring fewer inspection items and fewer personnel for commissioning and subsequent maintenance.

[0047] In the present invention, a dedicated cable channel is planned for the electrical connection between the various devices, which not only ensures smooth process wiring but also reduces the impact on the room.

[0048] In the present invention, the DC filter is eliminated and the smoothing reactor 210 is used to suppress the characteristic harmonics on the DC side, thereby reducing equipment investment, equipment operation and maintenance workload, and reducing platform size and weight.

[0049] In the present invention, the valve hall 100 is connected to the DC field 200 through a DC wall bushing.

[0050] In the present invention, the DC power distribution device of the DC field 200 adopts cable outlet, which is connected to the DC submarine cable through cable accessories and cable terminals, and then led out through a J-shaped pipe under the platform.

[0051] By comprehensively considering the layout requirements of functional rooms and auxiliary rooms, the present invention arranges rooms with larger sizes and more open equipment, such as the valve hall 100 and the DC field 200, at the lower part of the platform, and arranges the AC field 300 at the upper part of the platform. A cable room 500 is arranged between the upper and lower parts of the platform, thereby improving the space utilization of the platform and making the overall platform layout more compact. At the same time, a special cable layer is planned, which not only ensures smooth electrical connection between various devices, but also minimizes the platform size and saves steel.

[0052] The present invention uses a diode converter valve 110 with a quadruple valve structure. The valve tower is much smaller and lighter than a modular multi-level converter valve, which can reduce the size of the valve hall 100 and thus the size and weight of the platform.

[0053] The present invention employs a diode valve 110 and adopts an uncontrolled rectifier operation mode. The diode valve 110 has significantly lower operating losses than a modular multi-level valve, reducing the requirements for auxiliary equipment such as cooling units and air conditioning units, and reducing the size and weight of the auxiliary equipment room, thereby reducing the size and weight of the platform.

[0054] The application example of the present invention can reduce the platform unit capacity weight by more than 40% compared with the existing offshore converter station, and reduce the platform size by more than 15% compared with the existing offshore converter station.

[0055] In some embodiments, see Figure 2 、 Figure 4The valve hall 100 is equipped with two symmetrically arranged first power distribution devices 120 and diode converter valves 110. The DC field 200 is equipped with two symmetrically arranged second power distribution devices 220 and smoothing reactors 210. The AC field 300 is equipped with two symmetrically arranged third power distribution devices 310 and converter transformers 320. This embodiment uses symmetrical bipolar wiring. If any pole line or a single converter valve fails or requires maintenance, only part of the system is shut down, resulting in a loss of half the transmitted power. This improves system reliability and increases the availability of offshore converter stations.

[0056] In some embodiments, see Figure 2 The diode converter valve 110 is suspended and installed in the valve hall 100, using an "ABC" phase sequence in a straight line. The suspended structure is used. The valve tower has better seismic resistance than supported converter valves, facilitating platform transportation and installation.

[0057] In some embodiments, see Figure 9 The diode valve 110 and first power distribution device 120 in the valve hall 100 are arranged in a compact layout. Specifically, the Y-connected AC input and Δ-connected AC input lines of the diode valve 110 are arranged on either side of the diode valve 110. The DC busbars of the diode valve 110 are arranged between phases, perpendicular to the input line direction. The positive and negative DC output lines of the diode valve 110 are led out from between phases.

[0058] Traditional solution: The Y-connected and △-connected AC incoming lines are arranged in a line on the same side of the converter valve. The DC busbars are arranged perpendicular to the incoming line direction and overlapped in between phases. The positive and negative lines are led out along the converter valve.

[0059] The traditional solution places the Y-connection and the △-connection on the same side of the converter valve, corresponding one-to-one with the "AC-converter valve-DC" process flow. This makes the wiring clearer and simpler, but the air clearance of the AC side incoming line will lengthen the phase distance, and the space utilization between the converter valves and between the positive and negative lines is low, resulting in a more spacious and slender layout.

[0060] The solution of the present invention flexibly utilizes the wiring direction of the converter valve equipment, separates the Y-connected incoming line and the Δ-connected incoming line and arranges them on both sides of the converter valve. The DC outgoing line and the AC incoming line are staggered, which effectively utilizes the space around the converter valve, makes the layout more compact and square, and optimizes the spatial compactness and rationality of the layout of the entire platform.

[0061] In some embodiments, see Figure 1 、 Figure 2 The DC field 200 and the valve hall 100 are arranged adjacent to each other on the same floor, and the DC field 200 and the valve hall 100 are electrically connected using 230 and 240.

[0062] The smoothing reactor 210 (about 35 tons) cannot be transported by crane or crane. A maintenance hole is reserved directly above the smoothing reactor 210. No room is arranged directly above it, so that the lifting equipment can be directly extended from the top floor into the DC field 200 for lifting.

[0063] In some embodiments, the second power distribution device 220 utilizes a DC GIS device, such as a DC GIS device with a voltage level of ±500 kV. This DC GIS device is a gas-insulated, metal-enclosed DC switchgear that integrates a disconnector, grounding switch, lightning arrester, voltage measurement device, current measurement device, and other components. Compared to air-insulated, open-type DC devices (such as those used in other inventions), this device can be significantly smaller, have a longer service life, and achieve a more compact layout of the DC field 200.

[0064] In some embodiments, the third power distribution device 310 utilizes AC GIS equipment of 66 kV or higher, with a DC system capacity of 2000 MW. This corresponds to 30 or more circuits of the offshore wind farm's collector cable. The third power distribution device 310 is arranged in a straight line above the valve hall 100. A cable shaft 600 for laying the AC submarine cable is located to the side of the third power distribution device 310. The 66 kV AC submarine cable can reach directly to the bottom of the platform. A manhole is reserved on the side of the 66 kV AC GIS equipment above the open space in the room, allowing lifting equipment to directly access the 66 kV AC GIS equipment from the top floor for installation.

[0065] AC field 300 includes a converter transformer 320. This large, heavy unit (approximately 500 tons) makes it difficult to use the platform's built-in crane. Therefore, consideration was given to using an external crane vessel for lifting. To facilitate crane installation, converter transformer 320 was placed at the top of the platform, with a manhole provided. To facilitate platform center of gravity design, converter transformer 320 was symmetrically arranged in the center.

[0066] In some embodiments, see Figure 4 AC field 300 also includes a STATCOM device 330. A DC transmission system based on a diode valve solution generates low-frequency harmonics on the AC side during operation and consumes a certain amount of reactive power. STATCOM device 330 is used to eliminate the low-frequency harmonic currents generated by the diode valves and compensate for the reactive power. A manhole is provided directly above STATCOM device 330, allowing lifting equipment to be directly inserted from the top floor into the third distribution unit 310 for installation.

[0067] Among them, see Figures 1-4 、 Figure 8The third power distribution device 310, the converter transformer 320 and the STATCOM equipment 330 are arranged on the same floor. The third power distribution device 310 and the converter transformer 320 are connected by cables. The cables enter the cable room 500 from the cable shaft 600. There is an opening on the ground of the converter transformer 320 room, and the cables enter the converter transformer 320 room from the cable room 500 below. The third power distribution device 310 and the STATCOM equipment 330 are connected by cables. There is an opening on the ground of the STATCOM equipment 330 room, and the cables enter the STATCOM equipment 330 room from the cable room 500 below.

[0068] For further information, see Figure 4 A relay room 800 is provided on the top station floor. The relay room 800 includes an AC / DC relay room, a 66kV relay room, a valve cooling control and protection room, a STATCOM relay protection room, a communication room, and a battery room. A control and protection panel cabinet is provided in the relay room 800. The relay room 800 is arranged on the same floor as the AC field 300. The relay room 800 is located at the center of the third distribution device 310, the converter transformer 320, and the STATCOM equipment 330, which facilitates the connection of various devices to the control and protection panel cabinet, saves the length of the control cable, and saves investment.

[0069] See also Figure 3 The cable room 500 houses a transformer oil collection tank room 700 and an auxiliary room 400. The transformer oil collection tank room 700, located beneath the converter transformer 320, stores the insulating oil discharged from the transformer. The auxiliary room 400 includes an air-conditioning room, a water-cooling room, and a spare parts room. In addition to the cable room 500, an auxiliary room 400 is located on every floor of the platform.

[0070] A partition is provided on the top of the top station layer, in which a station power room 900 is provided. The station power room 900 is used to provide station power to the platform.

[0071] See also Figure 1 、 Figure 8 In some embodiments, the offshore converter station has a total of 7 floors, and a circular corridor is arranged along the periphery of the rooms on each floor.

[0072] Throughout this specification, references to terms such as "example," "embodiment," or "some embodiments" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0073] Of course, the invention is not limited to the above-mentioned embodiments. Those skilled in the art may make equivalent modifications or substitutions without violating the spirit of the invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. An offshore converter station, characterized in that: It includes a top station layer and a bottom station layer arranged in layers along the height direction. The bottom station layer is provided with a valve hall and a DC field. The valve hall is provided with a first distribution device and a diode converter valve connected to the first distribution device. The diode converter valve adopts a quadruple valve structure. The DC field is provided with a second distribution device and a smoothing inductor connected to the second distribution device. The top station layer is provided with an AC field. The AC field is provided with a third distribution device and a converter transformer. A cable room is provided between the top station layer and the bottom station layer. The cable room is provided with cables for connecting the equipment in the top station layer and the bottom station layer. The third distribution device is connected to an AC submarine cable externally. The third distribution device is connected to the converter transformer via a cable. The converter transformer is connected to the valve hall via a cable. The valve hall is connected to the DC field via a cable. The smoothing inductor is arranged on the DC pole line of the diode converter valve. The first distribution device of the DC field adopts a cable outlet.

2. The offshore converter station according to claim 1, characterized in that: The valve hall is provided with two symmetrically arranged sets of the first power distribution devices and diode converter valves, the DC field is provided with two symmetrically arranged sets of the second power distribution devices and smoothing reactors, and the AC field is provided with two symmetrically arranged sets of the third power distribution devices and converter transformers.

3. The offshore converter station according to claim 1, characterized in that: The diode commutation valve is suspended and installed in the valve hall.

4. The offshore converter station according to claim 1, characterized in that: The Y-connected AC incoming line and the △-connected AC incoming line of the diode converter valve are respectively arranged on both sides of the diode converter valve, the DC busbar of the diode converter valve is arranged between phases perpendicular to the incoming line direction, and the positive DC outgoing line and the negative DC outgoing line of the diode converter valve are led out from the phases.

5. The offshore converter station according to claim 1, characterized in that: The DC field and the valve hall are arranged adjacent to each other on the same floor. A DC wall bushing is used to electrically connect the DC field and the valve hall. A maintenance hole is reserved directly above the smoothing reactor.

6. The offshore converter station according to claim 1, characterized in that: The second power distribution device adopts DC GIS equipment.

7. The offshore converter station according to claim 1, characterized in that: The third power distribution device adopts AC GIS equipment above 66kV. The third power distribution device is arranged in a straight line above the valve hall. A cable shaft for laying AC submarine cables is arranged on the side of the third power distribution device.

8. The offshore converter station according to claim 7, characterized in that: A STATCOM device is also provided in the AC field. A maintenance hole is reserved directly above the STATCOM device. The third distribution device, converter transformer and STATCOM device are arranged on the same floor. The third distribution device is connected to the converter transformer with a cable. The cable enters the cable room from the cable shaft. A hole is opened on the ground of the converter transformer room, and the cable enters the converter transformer room from the cable room below. The third distribution device is connected to the STATCOM device with a cable. A hole is opened on the ground of the STATCOM device room, and the cable enters the STATCOM device room from the cable room below.

9. The offshore converter station according to claim 8, characterized in that: The top station layer is provided with a relay room, which is arranged on the same layer as the AC field. The relay room is located at the center of the third power distribution device, the converter transformer and the STATCOM equipment.

10. The offshore converter station according to claim 8, characterized in that: A transformer oil collecting tank room and an auxiliary room are provided in the cable room. The transformer oil collecting tank room is arranged below the converter transformer. A partition is provided on the top of the top station layer. A station power room is provided in the partition. A circular corridor is arranged along the periphery of the rooms on each floor.

Images