CN212392678U - Offshore power transmission system - Google Patents
Offshore power transmission system Download PDFInfo
- Publication number
- CN212392678U CN212392678U CN202021247701.2U CN202021247701U CN212392678U CN 212392678 U CN212392678 U CN 212392678U CN 202021247701 U CN202021247701 U CN 202021247701U CN 212392678 U CN212392678 U CN 212392678U
- Authority
- CN
- China
- Prior art keywords
- offshore
- converter station
- direct current
- voltage
- current
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 230000005540 biological transmission Effects 0.000 title claims abstract description 62
- 238000010248 power generation Methods 0.000 claims abstract description 19
- 238000003491 array Methods 0.000 claims description 4
- 238000000034 method Methods 0.000 description 10
- 238000010586 diagram Methods 0.000 description 9
- 238000004804 winding Methods 0.000 description 8
- 230000008569 process Effects 0.000 description 5
- 230000009471 action Effects 0.000 description 3
- 238000010276 construction Methods 0.000 description 3
- 230000009466 transformation Effects 0.000 description 3
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000006467 substitution reaction Methods 0.000 description 2
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/70—Wind energy
- Y02E10/76—Power conversion electric or electronic aspects
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/60—Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]
Landscapes
- Control Of Eletrric Generators (AREA)
Abstract
The utility model discloses an offshore power transmission system. Wherein, offshore transmission system includes: the offshore wind power generation system comprises a medium-voltage direct-current fan array, and the medium-voltage direct-current fan array outputs direct current; the marine delivery end converter station is arranged on the marine platform and is connected with the medium-voltage direct-current fan array, and the marine delivery end converter station boosts direct current output by the medium-voltage direct-current fan array to obtain boosted direct current; the system comprises an onshore receiving end converter station, wherein the onshore receiving end converter station is connected with an offshore sending end converter station through a direct current submarine cable, and the onshore receiving end converter station converts direct current transmitted by the direct current submarine cable into alternating current. According to the embodiment of the utility model provides a, can reduce the voltage loss in the transmission course, improve marine transmission system's economic nature.
Description
Technical Field
The utility model belongs to the technical field of the wind-powered electricity generation field, especially, relate to an offshore transmission system.
Background
China has abundant wind resource reserves, and China has offshore wind resources with abundant reserves. Compared with land wind power, offshore wind power has a series of advantages, such as high offshore wind speed, low vortex strength, low noise and the like, so that the development of offshore wind power is a new trend of wind power development.
With the increasing expansion of wind power generation capacity, wind power generation is more and more connected to a power grid, and the grid-connected operation of wind power becomes the most effective mode for utilizing wind energy on a large scale. The wind power grid-connected mode mainly comprises the following two modes: the system comprises an alternating current grid-connected mode and a direct current grid-connected mode, wherein the direct current grid-connected mode is more suitable for the development requirement of offshore wind power.
At present, when a conventional offshore wind power high-voltage direct-current power transmission system transmits electric energy, voltage loss in the transmission process is large, and therefore the economy of the offshore power transmission system is poor.
SUMMERY OF THE UTILITY MODEL
An embodiment of the utility model provides an offshore transmission system can reduce the voltage loss in the transmission course, improves offshore transmission system's economic nature.
An embodiment of the utility model provides an offshore transmission system, include:
the offshore wind power generation system comprises a medium-voltage direct-current fan array, and the medium-voltage direct-current fan array outputs direct current;
the marine delivery end converter station is arranged on the marine platform and is connected with the medium-voltage direct-current fan array, and the marine delivery end converter station boosts direct current output by the medium-voltage direct-current fan array to obtain boosted direct current;
the system comprises an onshore receiving end converter station, wherein the onshore receiving end converter station is connected with an offshore sending end converter station through a direct current submarine cable, and the onshore receiving end converter station converts direct current transmitted by the direct current submarine cable into alternating current.
In some embodiments, the marine send end converter station comprises:
the sending end inverter is connected with the medium-voltage direct current fan array and converts direct current output by the medium-voltage direct current fan array into alternating current;
the transmission end boosting transformer is connected with the transmission end inverter and boosts the alternating current output by the transmission end inverter to obtain boosted alternating current;
and the sending end rectifier is connected with the sending end boosting transformer and the direct current submarine cable, and converts alternating current output by the sending end boosting transformer into direct current and then inputs the direct current into the direct current submarine cable.
In some embodiments, the transmit side step-up transformer is an intermediate frequency step-up transformer.
In some embodiments, an offshore wind power generation system includes a plurality of medium voltage dc fan arrays, an offshore send-side converter station including a plurality of send-side inverters and a plurality of send-side step-up transformers;
the medium-voltage direct-current fan array is sequentially connected with a sending-end inverter and a sending-end boosting transformer, and the sending-end boosting transformers are connected with the sending-end rectifier in parallel.
In some embodiments, the marine send-end converter station further comprises:
the marine alternating current bus is connected with the transmitting end rectifier, and the plurality of transmitting end boosting transformers are respectively connected to the marine alternating current bus in parallel.
In some embodiments, the medium voltage dc wind turbine array includes a plurality of medium voltage dc wind power generating sets connected in parallel.
In some embodiments, the medium-voltage direct-current wind generating set comprises a wind generating set, a fan converter, a fan transformer and a fan rectifier, wherein the wind generating set is sequentially connected with the fan converter, the fan transformer and the fan rectifier;
the fan rectifiers of a plurality of medium-voltage direct-current wind generating sets in the medium-voltage direct-current fan array are connected in parallel.
In some embodiments, the onshore receiver converter station comprises:
and the receiving-end inverter is connected with the direct-current submarine cable and converts direct current transmitted by the direct-current submarine cable into alternating current.
In some embodiments, the system further comprises:
and the land booster transformer is respectively connected with the land receiving end converter station and the alternating current power grid, and boosts the alternating current output by the land receiving end converter station and inputs the boosted alternating current into the alternating current power grid.
In some embodiments, the system further comprises:
and the land alternating-current bus is respectively connected with the land receiving end converter station and the land booster transformer.
The offshore power transmission system of the embodiment of the utility model comprises an offshore wind power generation system, an offshore sending end converter station and an onshore receiving end converter station, wherein the offshore sending end converter station is connected with the offshore wind power generation system, the onshore receiving end converter station is connected with the offshore sending end converter station through a direct current submarine cable, a medium voltage direct current fan array of the offshore wind power generation system can output direct current, the offshore sending end converter station can receive the direct current output by the medium voltage direct current fan array and boost the received direct current to obtain boosted direct current, the onshore receiving end converter station can receive the direct current transmitted by a direct current submarine cable and convert the received direct current into alternating current, so that the electric energy is transmitted between the offshore wind power generation system and the offshore sending end converter station in a direct current form, and because the direct current transmission cable for transmitting the direct current has small voltage loss and large transmission capacity, therefore, the electric loss in the transmission process can be reduced, and the economy of the offshore power transmission system is improved.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the embodiments of the present invention will be briefly described below, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
FIG. 1 is a schematic structural diagram of an offshore wind power high voltage direct current transmission system in the related art;
fig. 2 is a schematic structural diagram of an offshore power transmission system according to an embodiment of the present invention;
fig. 3 is a schematic view of a topology structure of a medium voltage dc wind turbine generator system according to an embodiment of the present invention;
fig. 4 is a schematic diagram of a topology of a sending-end inverter according to an embodiment of the present invention;
fig. 5 is a schematic diagram of a topology of a sending-end rectifier according to an embodiment of the present invention;
fig. 6 is a schematic view of a connection structure of a dc submarine cable according to an embodiment of the present invention.
Detailed Description
The features and exemplary embodiments of various aspects of the present invention will be described in detail below, and in order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. It will be apparent to one skilled in the art that the present invention may be practiced without some of these specific details. The following description of the embodiments is merely intended to provide a better understanding of the invention by illustrating examples of the invention.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
Fig. 1 shows a schematic structural diagram of an offshore wind power high-voltage direct-current transmission system in the related art. As shown in fig. 1, the conventional offshore wind power High-Voltage Direct-Current transmission system is composed of a low-Voltage alternating-Current fan array 101, an offshore 35KV alternating-Current collection line 102, an offshore booster station 103, an offshore 220KV alternating-Current collection line 104, an offshore converter station 105, an offshore High-Voltage Direct-Current (HVDC) High-Voltage flexible Direct-Current transmission line 106, an offshore HVDC low-Voltage flexible Direct-Current transmission line 107, an onshore converter station 108, an onshore 220KV alternating-Current collection line 109, an onshore booster transformer 110, and an alternating-Current power grid 111.
Each low-voltage alternating-current fan array 101 is formed by connecting a plurality of groups of low-voltage alternating-current wind generating sets 112 in parallel, alternating current generated by each low-voltage alternating-current fan array 101 is collected through an offshore 35KV alternating-current collecting line 102, and then the collected alternating current is boosted through an offshore boosting station 103 to obtain 220KV alternating current. After a plurality of groups of offshore 220KV alternating current collecting lines 104 are collected, the collected alternating current is converted into direct current voltage suitable for a flexible direct current transmission line through an offshore converter station 105, the offshore wind power energy is transmitted to an onshore converter station 108 in a direct current mode through an offshore HVDC high-voltage flexible direct current transmission line 106 and an offshore HVDC low-voltage flexible direct current transmission line 107, the offshore wind power energy is inverted into the alternating current through the onshore converter station 108, finally the alternating current is boosted to the voltage suitable for an alternating current power grid 111 through an onshore booster transformer 110, and the boosted alternating current is input into the alternating current power grid 111 through a Point of Common Coupling (PCC).
With the increase of the area of the offshore wind farm, the lengths of cables of an offshore 35KV alternating current collecting line and an offshore 220KV alternating current collecting line are also increased, and due to the fact that the alternating current cables are large in loss and small in transmission capacity, the alternating current cables have large electric loss when used for transmitting electric energy in the offshore wind farm. Meanwhile, the offshore booster station needs a heavy power frequency transformer and redundant power transformation links, so that the offshore platform is large in load and high in construction cost.
In summary, the offshore wind power high voltage direct current transmission system in the related art has the problem of poor economy of the offshore wind power high voltage direct current transmission system when transmitting electric energy.
In order to solve the technical problem, the embodiment of the utility model provides an offshore transmission system can make the electric energy transmit in offshore wind power field with direct current's form, reduces the electrical loss in the transmission course, improves offshore transmission system's economic nature.
Fig. 2 shows a schematic structural diagram of an offshore power transmission system according to an embodiment of the present invention. As shown in fig. 2, the offshore power transmission system may include an offshore wind power generation system 210, an offshore send end converter station 220, and an onshore receive end converter station 230. The offshore wind power generation system 210 may include at least one medium-voltage dc fan array 211, the offshore sending-end converter station 220 may be disposed on an offshore platform, the offshore sending-end converter station 220 may be connected to the medium-voltage dc fan array 211, and the onshore receiving-end converter station 230 may be connected to the offshore sending-end converter station 220 through a dc sea cable 240.
Each medium voltage dc fan array 211 may output dc power, the offshore sending-end converter station 220 may receive the dc power output by the medium voltage dc fan array 211 and boost the dc power output by the medium voltage dc fan array 211 to obtain boosted dc power, the dc submarine cable 240 may transmit the dc power output by the offshore sending-end converter station 220 to the onshore receiving-end converter station 230, and the onshore receiving-end converter station 230 may receive the dc power transmitted by the dc submarine cable 240 and convert the dc power transmitted by the dc submarine cable 240 into ac power.
In the embodiment of the present invention, the offshore power transmission system may include an offshore wind power generation system 210, an offshore sending-end converter station 220 and an onshore receiving-end converter station 230, the offshore sending-end converter station 220 is connected to the offshore wind power generation system 210, the onshore receiving-end converter station 230 is connected to the offshore sending-end converter station 220 through a dc submarine cable 240, a medium-voltage dc fan array 211 of the offshore wind power generation system 210 can output dc power, the offshore sending-end converter station 220 can receive the dc power output by the medium-voltage dc fan array 211 and boost the received dc power to obtain boosted dc power, the onshore receiving-end converter station 230 can receive the dc power transmitted by the dc submarine cable 240 and convert the received dc power into ac power, so that the electric power is transmitted between the offshore wind power generation system 210 and the onshore receiving-end converter station 230 in the form of dc power, and the dc power is transmitted between the onshore receiving-end converter station 230 due to the small voltage loss of, The transmission capacity is large, so that the electric loss in the transmission process can be reduced, the direct current cable can save materials, the construction cost of the offshore transmission system is reduced, and the economy of the offshore transmission system is improved. In addition, the problem that large reactive voltage exists in the wind power plant in the related technology can be solved by using the direct current cable.
In some embodiments of the present invention, each medium voltage dc fan array 211 may include a plurality of medium voltage dc wind turbine generators 212, and the plurality of medium voltage dc wind turbine generators 212 in each medium voltage dc fan array 211 may be connected in parallel.
With continued reference to fig. 2, in some embodiments, the plurality of medium voltage dc wind turbine generators 212 in each medium voltage dc fan array 211 may be respectively connected in parallel to a group of medium voltage dc cables 213 in the offshore wind farm, and the medium voltage dc cables 213 in the group of offshore wind farm may correspond to one medium voltage dc fan array 211, so as to respectively connect in parallel the plurality of medium voltage dc wind turbine generators 212 in different medium voltage dc fan arrays 211.
The medium voltage direct current cables 213 in the offshore wind power plant may include medium voltage direct current high voltage cables in the offshore wind power plant and medium voltage direct current low voltage cables in the offshore wind power plant, the high voltage output end of the medium voltage direct current wind generating set 212 may be connected to the medium voltage direct current high voltage cables in the offshore wind power plant, and the low voltage output end of the medium voltage direct current wind generating set 212 may be connected to the medium voltage direct current low voltage cables in the offshore wind power plant.
In these embodiments, optionally, offshore send end converter station 220 may be connected to medium voltage dc fan array 211 by medium voltage dc cable 213 in an offshore wind farm.
In some embodiments of the present invention, the medium voltage dc wind turbine generator set 212 may be a wind turbine generator set with a medium voltage power electronic converter.
Fig. 3 shows a schematic view of a topology structure of a medium voltage dc wind turbine generator system according to an embodiment of the present invention. As shown in fig. 3, the medium voltage dc wind power plant 212 may include a wind power plant 214, a fan converter 215, a fan transformer 216 and a fan rectifier 217, the wind power plant 214 being connected to the fan converter 215, the fan transformer 216 and the fan rectifier 217 in turn. The fan converter 215, the fan transformer 216, and the fan rectifier 217 form the medium-voltage power electronic converter, and in other embodiments, the medium-voltage power electronic converter may have other structures, which is not limited herein.
In these embodiments, the fan rectifiers 217 of a plurality of medium voltage dc wind power plants 212 in the medium voltage dc fan array 211 are connected in parallel.
With continued reference to fig. 3, the wind turbine converter 215 may include a machine side converter 218 and a grid side converter 219, the machine side converter 218 and the grid side converter 219 may be connected by a dc bus. The fan transformer 216 may be a secondary multi-winding step-up transformer, wherein the fan transformer 216 has one set of primary windings and multiple sets of secondary windings. The fan rectifier 217 includes a plurality of three-phase uncontrolled rectifier bridges, the number of the plurality of three-phase uncontrolled rectifier bridges is the same as the number of the plurality of sets of secondary windings, each three-phase uncontrolled rectifier bridge corresponds to one set of secondary windings in the fan transformer 216, and each three-phase uncontrolled rectifier bridge is connected to the corresponding secondary winding.
The three-phase uncontrolled rectifier bridge comprises three diode branches connected in parallel, the three diode branches are identical in structure, two diodes are connected in series on each diode branch, the connection direction of each diode is identical, each output end of the three-phase alternating current output end of the secondary winding is connected with one diode branch in the corresponding three-phase uncontrolled rectifier bridge, and the output end of the secondary winding is connected between two diodes in the corresponding diode branch.
Optionally, a plurality of three-phase uncontrolled rectifier bridges in the fan rectifier 217 of each medium voltage dc wind turbine generator set 212 are connected in series in turn, finally forming a high voltage output and a low voltage output of the fan rectifier 217. Specifically, the high voltage output terminal of the first group of three-phase uncontrolled rectifier bridge is used as the high voltage output terminal of the fan rectifier 217, i.e. the high voltage output terminal of the medium voltage dc wind turbine generator set 212. The low voltage output terminals of the first group of three-phase uncontrolled rectifier bridges are connected with the high voltage output terminals of the second group of three-phase uncontrolled rectifier bridges, the three-phase uncontrolled rectifier bridges are sequentially connected in series according to the method, and the low voltage output terminals of the last group of three-phase uncontrolled rectifier bridges are used as the low voltage output terminals of the fan rectifier 217, namely the low voltage output terminals of the medium voltage direct current wind generating set 212. In general, the voltage level of the medium voltage dc wind park 212 may be boosted using a fan transformer 216 and a fan rectifier 217.
In the embodiment of the present invention, the ac voltage output by the grid-side converter 219 of the medium voltage dc wind generating set 212 is 690VAC, and the dc voltage output by the fan rectifier 217 can be raised to ± 30KV- ± 50KV, so that the electric energy can be transmitted in the form of dc in the offshore wind farm, and the ac cable is replaced by the dc cable.
Alternatively, the high voltage output of the fan rectifier 217 may be connected in parallel to a medium voltage dc high voltage cable in the offshore wind farm and the low voltage output of the fan rectifier 217 may be connected in parallel to a medium voltage dc low voltage cable in the offshore wind farm.
In some embodiments of the present invention, with continued reference to fig. 2, offshore send-end converter station 220 may include a send-end inverter 221, a send-end step-up transformer 222, and a send-end rectifier 223. The transmission inverter 221 is connected to the medium-voltage dc fan array 211, the transmission step-up transformer 222 is connected to the transmission inverter 221, and the transmission rectifier 223 is connected to the transmission step-up transformer 222 and the dc submarine cable 240.
The sending-end inverter 221 may convert the direct current output by the medium-voltage direct-current fan array 221 into alternating current, the sending-end step-up transformer 222 may step up the alternating current output by the sending-end inverter 221 to obtain stepped-up alternating current, and the sending-end rectifier 223 may convert the alternating current output by the sending-end step-up transformer 222 into direct current and input the direct current to the direct-current submarine cable 240.
Alternatively, the sending inverter 221 may be a dc-ac converter, the sending step-up transformer 222 may be an intermediate frequency step-up transformer, and the sending rectifier 223 may be an ac-dc converter.
Because the intermediate frequency step-up transformer is a power electronic converter with high power density, a heavy power frequency transformer and redundant power transformation links can be omitted, the load of the offshore platform is reduced, the construction cost of the offshore platform is further reduced, and the economy of the offshore power transmission system is further improved.
Fig. 4 shows a schematic diagram of a topology of a sending-end inverter according to an embodiment of the present invention. As shown in fig. 4, the sending-end inverter 221 may be a Modular Multilevel Converter (MMC), and includes three inverter branches 401 connected in parallel, where the three inverter branches 410 have the same structure, each inverter branch 401 is respectively connected in series with two first switch units 402, each first switch unit 402 includes a switch tube and an inductor connected in series, the two inductors in each inverter branch 401 are connected to each other, and the two switch tubes in each inverter branch 401 are respectively connected in parallel with the other inverter branches 401.
Three inverter branches 401 are connected in parallel to form two input ends of the sending-end inverter 221, an output end of the sending-end inverter 221 is further connected between two inductors in each inverter branch 401 to form a three-phase alternating current output end of the sending-end inverter 221, and a medium-voltage alternating current breaker 403 is further connected in series on each output end.
Optionally, two input ends of the sending-end inverter 221 are respectively connected with the medium-voltage direct-current high-voltage cable in the offshore wind farm and the medium-voltage direct-current low-voltage cable in the offshore wind farm of the corresponding group of medium-voltage direct-current cables 213 in the offshore wind farm. Three output terminals of the transmitting-side inverter 221 are connected to input terminals of the transmitting-side step-up transformer 222, respectively.
In some embodiments of the present invention, the sending-end rectifier 223 may include three parallel-connected rectifier branches.
Fig. 5 shows a schematic topology diagram of a sending-end rectifier according to an embodiment of the present invention. As shown in fig. 5, the sending-end rectifier 223 may include an MMC, the MMC includes three rectifier branches 501 connected in parallel, the three rectifier branches 501 have the same structure, two second switch units 502 are respectively connected in series on each rectifier branch 501, each second switch unit 502 includes a switch tube and an inductor connected in series, the two inductors in each rectifier branch 501 are connected to each other, and the two switch tubes in each rectifier branch 501 are respectively connected in parallel with the other rectifier branches 501.
The three rectifier branches 501 are connected in parallel to form two output ends of the sending-end rectifier 223, and an input end of the sending-end rectifier 223 can be formed between two inductors in each rectifier branch 501, so as to form a three-phase alternating current input end of the sending-end rectifier 223. The three-phase ac input terminal of the transmitting end rectifier 223 is used for connecting with the three-phase ac output terminal of the transmitting end step-up transformer 222.
In other embodiments of the present invention, the sending-end rectifier 223 can further include a step-up transformer 503, and the step-up transformer 503 can be a medium-voltage power-frequency step-up transformer. Because the medium-voltage power-frequency boosting transformer is a power electronic converter with high power density, a heavy power-frequency transformer and redundant power transformation links can be omitted, and the load of the offshore platform is reduced.
With continued reference to fig. 5, the three-phase ac output terminals of the step-up transformer 503 may be respectively connected to three rectifier branches 501, specifically, each output terminal of the three-phase ac output terminals of the step-up transformer 503 corresponds to one rectifier branch 501, each output terminal of the step-up transformer 503 is respectively connected between two inductors of the corresponding rectifier branch 501, and the three-phase ac input terminals of the step-up transformer 503 may be respectively connected to the three-phase ac output terminals of the sending-end step-up transformer 222.
Alternatively, the two output terminals of the sending-end rectifier 223 may be connected to the dc submarine cable 240, respectively.
Fig. 6 shows a schematic connection structure diagram of a direct current submarine cable according to an embodiment of the present invention. As shown in fig. 6, the dc sea cable 240 may comprise an offshore HVDC high voltage flexible dc transmission line 241 and an offshore HVDC low voltage flexible dc transmission line 242. The high voltage output of the send end rectifier 223 may be connected to the offshore HVDC high voltage flexible direct current transmission line 241 and the low voltage output of the send end rectifier 223 may be connected to the offshore HVDC low voltage flexible direct current transmission line 242.
In the embodiment of the present invention, the ac voltage output from the sending-end inverter 221 is 35KVAC, the ac voltage output from the sending-end step-up transformer 222 is 220KVAC, the ac voltage output from the step-up transformer in the sending-end rectifier 223 is 400KVAC, and the dc voltage output from the sending-end rectifier 223 is ± 320 kvc or ± 400 kvc.
In some embodiments of the present invention, offshore wind power generation system 210 may include a medium voltage dc fan array 211, and offshore send-side converter station 220 may include a send-side inverter 221, a send-side step-up transformer 222, and a send-side rectifier 223. At this time, the medium voltage dc fan array 211 may be sequentially connected to the feeding inverter 221, the feeding step-up transformer 222, and the feeding rectifier 223 through a set of medium voltage dc cables 213 in the offshore wind farm.
In other embodiments of the present invention, the offshore wind power generation system 210 may include a plurality of medium voltage dc fan arrays 211, the offshore transmission-side converter station 220 may include a plurality of transmission-side inverters 221, a plurality of transmission-side step-up transformers 222, and a transmission-side rectifier 223, one transmission-side inverter 211 corresponding to one medium voltage dc fan array 211, and one transmission-side step-up transformer 222 corresponding to one transmission-side inverter 221. At this time, one medium voltage dc fan array 211 may be sequentially connected to the corresponding delivery side inverter 221 and delivery side step-up transformer 222 through a group of medium voltage dc cables 213 in the offshore wind farm, and a plurality of delivery side step-up transformers 222 may be connected in parallel to one delivery side rectifier 223.
In some embodiments, the three-phase ac output terminals of the plurality of sending-side step-up transformers 222 may be directly connected in parallel to the three-phase ac input terminals of the sending-side rectifier 223.
In other embodiments, offshore send end converter station 220 may further include an offshore ac bus 224, offshore ac bus 224 may be connected to the three-phase ac input of send end rectifier 223, and the three-phase ac outputs of the plurality of send end step up transformers 222 may each be connected in parallel to offshore ac bus 224.
Wherein the offshore ac bus 224 may be a three-phase ac collection bus.
In some embodiments of the present invention, the onshore receiving end converter station 230 may include a receiving end inverter, the receiving end inverter may be connected to the dc submarine cable 240, and the receiving end inverter may convert the dc power transmitted by the dc submarine cable 240 into ac power.
The receiving-side inverter and the sending-side inverter 221 have similar topology structures, and are not described herein again.
Optionally, with continued reference to fig. 6, the high voltage input of the onshore receiver converter station 230 may be connected to an offshore HVDC high voltage flexible direct current transmission line 241 and the low voltage input of the onshore receiver converter station 230 may be connected to an offshore HVDC low voltage flexible direct current transmission line 242.
In some embodiments of the present invention, with continued reference to fig. 2, the offshore transmission system may further include a land step-up transformer 250, the land step-up transformer 250 may be respectively connected to the land receiving end converter station 230 and the ac power grid 260, and the land step-up transformer 250 may boost the ac power output by the land receiving end converter station and then input the ac power grid 260, thereby transmitting the offshore wind power energy to the land power grid.
In some embodiments of the present invention, the offshore power transmission system may further include a land ac bus 270, and the land ac bus 270 may be connected to the land receiving end converter station 230 and the land step-up transformer 250, respectively. The onshore ac bus 270 may be an onshore 220KV ac trunk line.
As described above, only the specific embodiments of the present invention are provided, and those skilled in the art can clearly understand that, for the convenience and simplicity of description, the specific working processes of the system, the module and the unit described above can refer to the corresponding processes in the foregoing method embodiments, and are not described herein again. It should be understood that the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive various equivalent modifications or substitutions within the technical scope of the present invention, and these modifications or substitutions should be covered by the scope of the present invention.
Claims (10)
1. An offshore power transmission system, comprising:
an offshore wind power generation system comprising a medium voltage direct current fan array that outputs direct current;
the offshore delivery end converter station is arranged on an offshore platform and is connected with the medium-voltage direct-current fan array, and the offshore delivery end converter station boosts direct current output by the medium-voltage direct-current fan array to obtain boosted direct current;
the system comprises an onshore receiving end converter station, wherein the onshore receiving end converter station is connected with the offshore sending end converter station through a direct current submarine cable, and the onshore receiving end converter station converts direct current transmitted by the direct current submarine cable into alternating current.
2. The system of claim 1, wherein the marine delivery end converter station comprises:
the sending end inverter is connected with the medium-voltage direct current fan array and converts direct current output by the medium-voltage direct current fan array into alternating current;
the transmission end boosting transformer is connected with the transmission end inverter and boosts the alternating current output by the transmission end inverter to obtain boosted alternating current;
and the sending end rectifier is connected with the sending end boosting transformer and the direct current submarine cable, and converts alternating current output by the sending end boosting transformer into direct current and then inputs the direct current into the direct current submarine cable.
3. The system of claim 2, wherein the sending-side step-up transformer is an intermediate frequency step-up transformer.
4. The system of claim 2, wherein said offshore wind power generation system comprises a plurality of said medium voltage dc fan arrays, and said offshore send-side converter station comprises a plurality of said send-side inverters and a plurality of said send-side step-up transformers;
the medium-voltage direct-current fan array is sequentially connected with the sending-end inverter and the sending-end boosting transformer, and the sending-end boosting transformers are connected with the sending-end rectifier in parallel.
5. The system of claim 4, wherein the marine delivery end converter station further comprises:
an offshore AC bus connected with the delivery side rectifier and to which the plurality of delivery side step-up transformers are respectively connected in parallel.
6. The system of claim 1, wherein the medium voltage dc fan array comprises a plurality of medium voltage dc wind power plants, the plurality of medium voltage dc wind power plants being connected in parallel.
7. The system of claim 6, wherein the medium voltage DC wind turbine generator system comprises a wind turbine generator system, a fan converter, a fan transformer and a fan rectifier, and the wind turbine generator system is connected with the fan converter, the fan transformer and the fan rectifier in sequence;
wherein the fan rectifiers of a plurality of the medium voltage DC wind turbine generators in the medium voltage DC fan array are connected in parallel.
8. The system of claim 1, wherein the onshore receiver converter station comprises:
and the receiving-end inverter is connected with the direct-current submarine cable and converts direct current transmitted by the direct-current submarine cable into alternating current.
9. The system of claim 1, further comprising:
and the land booster transformer is respectively connected with the land receiving end converter station and the alternating current power grid, and boosts the alternating current output by the land receiving end converter station and then inputs the boosted alternating current into the alternating current power grid.
10. The system of claim 9, further comprising:
and the land alternating current bus is respectively connected with the land receiving end converter station and the land booster transformer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202021247701.2U CN212392678U (en) | 2020-06-30 | 2020-06-30 | Offshore power transmission system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202021247701.2U CN212392678U (en) | 2020-06-30 | 2020-06-30 | Offshore power transmission system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN212392678U true CN212392678U (en) | 2021-01-22 |
Family
ID=74255969
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202021247701.2U Active CN212392678U (en) | 2020-06-30 | 2020-06-30 | Offshore power transmission system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN212392678U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114285070A (en) * | 2021-11-17 | 2022-04-05 | 中国华能集团清洁能源技术研究院有限公司 | Wind power generation collection system with serially connected fans |
| CN114285068A (en) * | 2021-11-17 | 2022-04-05 | 中国华能集团清洁能源技术研究院有限公司 | Wind power generation collection system with fans connected in parallel and networked |
-
2020
- 2020-06-30 CN CN202021247701.2U patent/CN212392678U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114285070A (en) * | 2021-11-17 | 2022-04-05 | 中国华能集团清洁能源技术研究院有限公司 | Wind power generation collection system with serially connected fans |
| CN114285068A (en) * | 2021-11-17 | 2022-04-05 | 中国华能集团清洁能源技术研究院有限公司 | Wind power generation collection system with fans connected in parallel and networked |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105226714A (en) | A kind of offshore wind farm direct current converges transmission system and method for designing | |
| CN103607032B (en) | Renewable energy power generation, power transmission and transformation and electrical network access integral system | |
| EP2810353A2 (en) | Dc connection scheme for windfarm with internal mvdc collection grid | |
| US20140091630A1 (en) | Medium voltage dc collection system with power electronics | |
| CN102142688B (en) | Electric power grid connecting system as well as electric power transmission system and method | |
| CN212392678U (en) | Offshore power transmission system | |
| CN113794226A (en) | Low-frequency alternating-current power transmission system of offshore wind farm | |
| CN110556864A (en) | Remote power transmission converter station and power transmission system | |
| CN107634543A (en) | A kind of offshore wind farm booster system and step-up method | |
| CN113258598B (en) | Topological circuit for offshore wind power direct current output and control method | |
| CN115021307A (en) | New energy power station direct current collection networking system and method | |
| CN113241808A (en) | Offshore wind power alternating current and direct current networking system and working method thereof | |
| CN212392677U (en) | Offshore power transmission system | |
| CN205123278U (en) | Marine wind power direct current assembles power transmission system | |
| CN106849158A (en) | A kind of wind generator system for series direct current marine wind electric field | |
| CN116014785A (en) | Marine wind power medium-voltage direct current collection and distributed series direct current transmission system | |
| CN114362183A (en) | Offshore wind power low-frequency alternating-current power transmission system topology based on active phase-change current source converter | |
| CN210693470U (en) | Converter station and power transmission system | |
| CN209072369U (en) | Ac-dc conversion device, wind power generating set and windfarm system | |
| CN113595067A (en) | Novel deep and distant sea wind power transmission system based on medium-low-power frequency collection | |
| CN109617120A (en) | Direct-current wind generating set and wind power plant | |
| CN113783217A (en) | Flexible direct current transmission system | |
| CN113098061A (en) | Offshore shore power low-frequency power transmission method based on modular multilevel converter | |
| CN216851309U (en) | Converter device of direct current wind turbine generator | |
| CN214850510U (en) | Offshore wind power alternating current and direct current networking system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |