CN113659612A - Wind generating set operation method based on offshore wind power bus system - Google Patents
Wind generating set operation method based on offshore wind power bus system Download PDFInfo
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/12—Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load
- H02J3/16—Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load by adjustment of reactive power
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/24—Arrangements for preventing or reducing oscillations of power in networks
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/46—Controlling of the sharing of output between the generators, converters, or transformers
- H02J3/50—Controlling the sharing of the out-of-phase component
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
- H02J2300/20—The dispersed energy generation being of renewable origin
- H02J2300/28—The renewable source being wind energy
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- 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
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- 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
- Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
- Y02E40/30—Reactive power compensation
Abstract
The invention discloses a wind generating set operation method based on an offshore wind power bus system, which comprises the following steps: when the rated frequency of the offshore wind power generation bus type system is 50/3 +/-5 percent Hz, the medium-voltage direct-matching semi-direct-drive double-fed generator is adopted, and when the rated frequency of the offshore wind power generation bus type system is 10 +/-17 percent Hz, the medium-voltage direct-matching direct-drive double-fed generator is adopted. The problems that one of the processes of offshore long-distance and large-range power transmission safe and reliable operation, investment cost efficiency and life cycle power cost in the process of transmitting power to shore from 5-20GW grade wind power generation to the deep and far sea are solved, and the problems that expensive high-power electronic equipment and large-scale heavy mechanical power transformation equipment cannot effectively resist and reduce disasters when encountering typhoon, fire, salt mist and other intrusions on the sea are solved.
Description
Technical Field
The invention belongs to the technical field of offshore deep and remote sea wind power generation, and particularly relates to an operation method of a medium-voltage direct-distribution double-fed wind generating set based on an offshore wind power bus system (frequency division/low-frequency power grid).
Background
Wind energy is an important energy source as a clean renewable new energy source. At present, the large-scale development of offshore windfarms is greatly developed. The wind power resources to be developed in deep open sea are very rich; how to improve the benefit and the predictable return rate of the deep and far sea wind power resource development and reduce the full life cycle electricity cost of a wind power plant is urgent to need an advanced technology for effectively developing the deep and far sea wind power resource, which is a problem to be solved urgently at present.
The offshore conventional high-voltage alternating-current booster station and the submarine high-voltage cable are used for power transmission on shore for a long distance (more than 70km), the load moment is small, the power transmission cost is high, the offshore conventional high-voltage booster station has high requirement on resisting severe offshore environment, and the offshore conventional high-voltage booster station cannot be rescued when a nonresistible fire disaster occurs; the main equipment on the single-circuit ashore network-accessing high-voltage alternating-current transmission circuit has faults, and the wind turbine generator on which the circuit needs to be on the network cannot normally generate electricity to operate, so that the safety of the typhoon wind turbine generator faces a great risk.
The offshore conventional high-voltage direct-current converter station and the seabed high-voltage direct-current cable are used for power transmission on shore for a long distance (more than 70km), the load moment is high, the cost of the offshore converter station is high, the offshore conventional high-voltage direct-current converter station has high requirement on resisting severe offshore environment, and the offshore conventional high-voltage direct-current converter station cannot be rescued when a nonresistible fire disaster occurs; when main equipment on a single-circuit ashore network-accessing high-voltage direct-current power transmission circuit fails, a wind turbine generator on the circuit cannot normally generate power and operate, and if safety of a typhoon wind turbine generator faces a great risk.
Disclosure of Invention
The invention aims to solve the problems of safety, reliability, efficiency, cost performance and the like of the conventional power frequency alternating current high-voltage power transmission and direct current high-voltage power transmission ashore scheme for deep and open sea offshore wind power generation and long-distance power transmission. Therefore, for the offshore wind power generation and long-distance power transmission in deep sea, an operation method of the wind generating set based on the offshore wind power bus system is provided.
The purpose of the invention is realized by the following technical scheme:
a wind generating set operation method based on an offshore wind power bus system comprises the following steps: when the rated frequency of the offshore wind power generation bus type system is 50/3 +/-5 percent Hz, the medium-voltage direct-matching semi-direct-drive double-fed generator is adopted, and when the rated frequency of the offshore wind power generation bus type system is 10 +/-17 percent Hz, the medium-voltage direct-matching direct-drive double-fed generator is adopted.
According to a preferred embodiment, the wind power plant virtual generators of a plurality of adjacent wind power plants on the sea enter the line longitudinally through the junction double buses; and the upper bus and the lower bus in the plurality of adjacent hub double buses are respectively connected by a transverse connecting line between the hub double buses to form an offshore wind power bus system of the offshore frequency division/low-frequency power grid.
According to a preferred embodiment, the offshore crossover/low frequency power grid comprises: the method comprises the following steps that (1) the frequency division/low frequency power transmission network side of an offshore wind farm virtual generator cluster, the frequency division/low frequency power grid side of a VSC cluster; the two-path longitudinal outgoing line output of each wind power plant virtual generator looped network in the offshore wind power plant virtual generator cluster is realized, and the network is connected from the frequency division/low frequency power grid side of the VSC cluster through the offshore frequency division/low frequency power transmission network.
According to a preferred embodiment, the offshore crossover/low frequency transmission network comprises two longitudinal output lines of each wind farm virtual generator ring network. The system comprises a corresponding hinge double-bus longitudinal incoming line in the longitudinal output section of the offshore wind farm, a corresponding hinge double-bus longitudinal outgoing line in the longitudinal output section of the offshore wind farm, and a transverse connecting line between each hinge double-bus and each hinge double-bus in the offshore wind power bus system.
According to a preferred embodiment, the offshore wind farm virtual generator cluster comprises a plurality of wind farm virtual generators, each wind farm virtual generator is provided with a plurality of power generation units and a plurality of boosting high-impedance transformers, and each power generation unit is provided with a plurality of medium-voltage direct-distribution doubly-fed wind turbine generators.
According to a preferred embodiment, the wind power generation unit adopts a boost high-impedance transformer, and regulates the voltage deviation of the medium-voltage direct-distribution double-fed wind power generator set on the internet in cooperation with the output reactive power of the medium-voltage direct-distribution double-fed wind power generator set. Meanwhile, the short-time operation range of high voltage ride through and low voltage ride through can be improved; the rated voltage range and the high voltage ride through range can be dynamically and stably widened. Selecting u as the percentage value of the impedance voltage of the boosting high-impedance transformerdT％＝12～36。
The main scheme and the further selection schemes can be freely combined to form a plurality of schemes which are all adopted and claimed by the invention; in the invention, the selection (each non-conflict selection) and other selections can be freely combined. The skilled person in the art can understand that there are many combinations, which are all the technical solutions to be protected by the present invention, according to the prior art and the common general knowledge after understanding the scheme of the present invention, and the technical solutions are not exhaustive herein.
The invention has the beneficial effects that: the invention adopts a wind generating set operation method based on an offshore wind power bus system, and solves the problems that one of the processes of offshore long-distance and large-range power transmission safe and reliable operation, the whole investment cost efficiency and the life cycle power cost in the process of transmitting wind power generation and power transmission of 5-20GW grades to shore, and the problem that expensive high-power electronic equipment and large-scale heavy mechanical power transformation equipment cannot effectively resist disasters and reduce disasters when encountering the interferences such as typhoons, fires, salt fog and the like on the sea.
After the offshore wind power bus system based on the offshore frequency division/low-frequency power grid is used, the capacity of the power transmission and transformation equipment of the on-line channel of each wind power plant can be reduced by 40% p.u., the cost can be saved by 40%, and the power transmission investment cost is greatly reduced.
The medium-voltage direct-distribution double-fed wind generating set is obtained by interconnecting the offshore frequency division/low-frequency power grids, the capacities of a booster and a converter of a single main loop are greatly reduced, the cost of the wind generating set is greatly reduced, 80-90% of the capacity of a primary booster transformer is reduced, the efficiency is improved by 0.8%, and the cost of the whole wind generating set can be reduced by 5-10%. The total investment of each virtual generator (wind power plant) with the level of 1GW is estimated to be reduced by about 8-10% on average; the cost performance of the whole offshore wind farm operation is greatly improved, and the full life cycle electricity consumption cost of the wind farm is reduced. The offshore wind power plant power transmission and transformation system adopts a redundant structure and really has an N-1 safety criterion for power generation and operation; safe and reliable operation is maximized, daily operation and maintenance workload and time windows are minimized, and the availability and maintainability of the whole offshore and onshore wind power generation and transmission equipment are improved.
Drawings
FIG. 1 is a schematic diagram of a power generation flow of a wind farm virtual generator cluster of an offshore frequency division/low frequency power grid according to the present invention;
FIG. 2 is an offshore wind power bus system of the present invention;
FIG. 3 is a marine crossover/low frequency power grid of the present invention;
FIG. 4 is a wind farm virtual generator of the present invention;
FIG. 5 is a portion of a wind farm virtual generator A of the present invention;
FIG. 6 is a portion B of a wind farm virtual generator of the present invention;
FIG. 7 is a portion of a wind farm virtual generator C of the present invention;
FIG. 8 is a portion of a wind farm virtual generator D of the present invention;
FIG. 9 is a schematic diagram of a P-n curve of a direct voltage distribution double-fed wind turbine generator set according to the invention;
wherein, 1-50Hz electric network, 2-VSC cluster, 3-VSC cluster frequency division/low frequency electric network side, 4-longitudinal output u section, 5-offshore wind power bus system, 6-longitudinal output d section, 7-virtual generator cluster, 8-VSC (left circuit, right circuit), 9-frequency division/low frequency electric transmission network, 10-junction double bus transverse connecting line, 11-junction double bus longitudinal outlet line, 12-junction double bus, 13-junction double bus longitudinal inlet line, 14-virtual generator, 15-frequency division/low frequency electric network, 16-high voltage collecting cable, 17-medium voltage collecting ring network cabinet, 18-medium voltage collecting cable, 19-boost high impedance transformer, 20-high voltage collecting ring network cabinet, 21-medium voltage direct distribution double-fed wind power generator set, 22-double-fed converter, 23-direct drive double-fed generator, 24-semi-direct drive double-fed generator, 25-gearbox, 26-hub, 27-blades, 28-rotor circuit transformer, 29-generating unit.
Detailed Description
The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It is to be noted that the features in the following embodiments and examples may be combined with each other without conflict.
It should be noted that, in order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described below, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments.
Thus, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
In addition, it should be noted that, in the present invention, if the specific structures, connection relationships, position relationships, power source relationships, and the like are not written in particular, the structures, connection relationships, position relationships, power source relationships, and the like related to the present invention can be known by those skilled in the art without creative work on the basis of the prior art.
Example (b):
referring to fig. 1 to 9, the invention discloses a method for operating a wind generating set based on an offshore wind power bus system. When the rated frequency of the offshore frequency division/low-frequency power grid is 50/3 +/-5% Hz, a semi-direct-drive double-fed generator is adopted and is provided with a primary or secondary gear box; the rated frequency of the offshore frequency division/low-frequency power grid is 10 +/-17% Hz at low frequency, and a direct-drive double-fed generator is adopted without a gear box. The rated voltage range of the rotor is 0.69 kV-10 kV, the rated voltage range of the stator is 0.69 kV-35 kV, and the capacity range of the generator set is 5 MW-50 MW.
The wind power plant virtual generators of a plurality of adjacent wind power plants on the sea enter the wind power plant through the junction double buses of the wind power plant virtual generators; and the upper bus and the lower bus in the plurality of adjacent hub double buses are respectively connected by a transverse connecting line between the hub double buses to form an offshore wind power bus system of the offshore frequency division/low-frequency power grid.
The offshore frequency division/low frequency power grid comprises an offshore wind farm virtual generator cluster, a frequency division/low frequency power transmission network and a VSC cluster frequency division/low frequency power grid side; wherein: two-way output of each wind power plant virtual generator in the longitudinal direction corresponds to the longitudinal line entering of a pivot double-bus in a section d of the longitudinal line outgoing of the offshore wind power plant, corresponds to the pivot double-bus in an offshore wind power plant bus system, corresponds to the longitudinal line outgoing of the pivot double-bus in a section u of the longitudinal output of the offshore wind power plant, and corresponds to the sides (left and right sides) of a VSC (voltage source converter) in the frequency division/low frequency power grid side of the VSC cluster. Two paths of output of each wind power plant virtual generator in the transverse direction correspond to upper buses and lower buses of the double junction buses in the offshore wind power bus system, and the upper buses and the lower buses are connected through transverse connecting lines between the double junction buses (hot standby connection between each double junction bus).
A plurality of adjacent wind power plants on the sea in deep and far sea are required, a virtual generator of the wind power plants longitudinally enters the wind power plants through a junction double bus, and a plurality of upper buses and lower buses of the adjacent junction double buses are respectively connected through a transverse connecting line between the junction double buses (hot standby connection between each double bus) to form an offshore wind power bus system of the offshore frequency division/low-frequency power transmission network.
An offshore crossover/low frequency power transmission network comprising: two-way output of each wind power plant virtual generator in the longitudinal direction corresponds to the longitudinal incoming line of a hinge double-bus in a section d of the longitudinal outgoing line of the offshore wind power plant, corresponds to the hinge double-bus in an offshore wind power bus system, corresponds to the longitudinal outgoing line of the hinge double-bus in a section u of the longitudinal output of the offshore wind power plant, and corresponds to the sides (left and right sides) of a VSC (voltage source converter) in the frequency division/low frequency power grid side of the VSC cluster; two paths of output of each wind power plant virtual generator in the transverse direction correspond to upper buses and lower buses of the double junction buses in the offshore wind power bus system, and the upper buses and the lower buses are connected through transverse connecting lines between the double junction buses (hot standby connection between each double junction bus).
The double-bus longitudinal incoming line of the offshore wind farm hub faces a high-voltage current collecting ring network cable, a high-voltage current collecting ring network cabinet and a wind farm power generation unit and can be equivalent to a virtual generator of a wind farm.
The input side of the high-voltage current collection ring main unit in the virtual generator of the offshore wind farm faces to the boosting high-impedance transformer, the medium-voltage current collection ring main unit, the medium-voltage direct-distribution double-fed wind turbine generator and is equivalent to a wind farm power generation unit.
The rated frequency of the offshore frequency division/low-frequency power grid adopts conventional frequency division 161/3 Hz, 80% p.u. cable capacity can transmit power for 270km, and the requirements of longitudinal 70-150km and transverse 200-120km deep and open sea offshore wind power transmission in an offshore area can be met. The rated frequency of the offshore frequency division/low-frequency power grid adopts low-frequency power transmission distance 440km with low frequency of 10Hz and 80% p.u. cable capacity, and can meet the requirements of offshore wind power transmission of 70-200km in the longitudinal direction and 240km in the transverse direction in the deep and far sea in the offshore area. Therefore, by adopting an offshore frequency division/low-frequency power grid (offshore wind power bus type system), the longitudinal and transverse power transmission distance on the sea or on the land can be further expanded, and the deep and distant sea wind power can be effectively transmitted to a load center in a long distance.
The operation method of the wind generating set based on the offshore wind power bus system is equivalent to that the large-scale high-voltage direct current converter station of the offshore flexible direct current scheme is basically equivalently moved to the land, the large-scale high-voltage alternating current booster station of the offshore high-voltage alternating current scheme is dispersed to each wind power station generating unit with small capacity and ring network connection, and the safety is greatly improved; meanwhile, a two-way high-voltage collecting ring network and a two-layer medium-voltage collecting ring network with high cost performance and high reliability of the wind power plant are adopted; the hot standby connection of the double-fed wind generating set at the tail end of the same type of different wind power generating units is safe and reliable in operation; the double-fed wind generating set of the wind power generation unit has an internet loop fault, and island microgrid connection operation can be realized; the offshore wind power plant power transmission and transformation system adopts a redundant structure and really has an N-1 safety criterion for power generation and operation; the method and the system avoid the great challenges of safety reliability and availability of the HVDC offshore converter station and the HVAC booster station due to severe offshore environment, reduce the equipment maintenance time and avoid the situation that large-scale offshore main station equipment cannot be rescued at all when a fire disaster happens.
The offshore frequency division/low-frequency power grid comprises an offshore wind farm virtual generator cluster, a frequency division/low-frequency power transmission grid and a VSC cluster frequency division, and the low-frequency power grid side really has the operation requirement of 'N-1' safety criterion.
Compared with the conventional power frequency high-voltage alternating current and high-voltage direct current transmission, the wind generating set operation method based on the offshore wind power bus type system has the advantages of higher investment return rate, higher full life cycle electricity cost, higher operation safety and reliability, higher efficiency, higher generated energy, higher cost performance and higher dynamic and static voltage stability of the offshore wind power plant wind generating set.
Specifically, the method comprises the following steps:
fig. 1 shows the flow of the offshore crossover/low frequency grid 15 power generation, transmission, VSC conversion to a 50Hz grid 1. In the wind farm virtual generator cluster 7, there are n wind farm virtual generators 14, and any one wind farm virtual generator
The wind power plant longitudinally outputs a d section 6, the power on the internet passing through a section 1 is less than or equal to 85% pu (corresponding to the wind power plant installation capacity), the power on the internet passing through a section 2 is less than or equal to 50% pu. after being input to a junction double bus i (power on the internet) in the offshore wind power bus system 5, and then the power on the internet passes through two ways in a u section 4 longitudinally output by the wind power plant to the onshore VSCi1/VSCi2Frequency division/low frequency power grid side conversion to VSCi1/VSCi2The total power of the section 3 on the 50Hz power grid side is less than or equal to 50% pu., and the power entering the 50Hz power grid 1 is less than or equal to 50% pu. (1pu. corresponds to the i wind power plant installation capacity); or the total power of the two paths of transverse output on-grid power of the left side and the right side of the junction double bus i is less than or equal to 35% pu (1pu. corresponding to the i wind power plant installation capacity), the total power of the on-grid power of the u section 4 of the longitudinal output of other wind power plants is less than 50% pu. longitudinal channel (section 2) respectively through other junction double buses 12 and the input longitudinal output u section of other wind power plants, then the total power of the on-grid power is converted to the 50Hz grid side (section 3, figure 1) of the VSC (left circuit and right circuit) 8 through the frequency division/low frequency grid side of the VSC (left circuit and right circuit), and finally the power enters the 50Hz grid 1.
A plurality of wind power plant virtual generators 14 of an offshore wind power plant longitudinally enter a line 13 to a corresponding hub double bus 12 through the hub double bus; an offshore wind power bus system 5 (fig. 2) of an offshore frequency division/low-frequency power grid 15 is formed by connecting a plurality of upper buses and upper buses of adjacent junction double buses 12 and lower buses of the junction double buses (hot standby connection is formed between the upper buses and the lower buses of each junction double bus) respectively through cables 10 connected in a transverse connection mode between the junction double buses.
For any ith wind power plant virtual generator 14, corresponding to offshore wind power on the longitudinal Internet access channelThe ith junction double bus 12 in the bus-type system 5 (figure 2) comprises an upper bus and a lower bus, and the longitudinal incoming line 13 of the left junction double bus of the upper bus inputs power P'i1The output power P of the right pivot button double bus longitudinal outgoing line 11 ″i2The lower bus right hub double-bus longitudinal incoming line 13 is used for inputting power P'i2The output power P of the left pivot double bus longitudinal outgoing line 11 ″i1The ith hub double bus longitudinal 12 longitudinal input total power (P'i1+P′i2Pu ≤ 85%, and the total power (P ″) output longitudinally by the double bus 12 at the ith pivot jointi1+P″i2Pu no more than 50%); an upper bus left junction double busbar inter-transverse connecting line 10 of the ith pivot junction double busbar 12 inputs or outputs power delta P'(i-1)1-i1Right pivotal link double busbar interconnecting transverse connection line 10 input or output power delta P'i1-(i+1)1And the lower bus left hub double inter-bus transverse connection line 10 inputs or outputs power delta P'(i-1)2-i2Right pivotal link double busbar interconnecting transverse connection line 10 input or output power delta P'i2-(i+1)2(ii) a I pivotal hinge double bus 12 right pivotal upper double bus/lower bus transverse connection line 10 input or output power (| delta P'(i-1)1-i1+ΔP′(i-1)2-i2| ≧ 35% pu'i1-(i+1)1+ΔP′i2-(i+1)2| ≧ 35% pu.). The upper bus and the lower bus of the ith pivot double bus 12 are connected with a hot standby of a communication switch.
A divided/low frequency offshore power grid 15 (fig. 3), comprising: an offshore wind farm virtual generator cluster 7, a frequency division/low frequency transmission network 9 and a VSC cluster frequency division/low frequency grid side 3; each wind power plant virtual generator 14 has two looped network longitudinal outgoing line outputs, namely a corresponding junction double-bus longitudinal incoming line 13 in the longitudinal output d section 6 of the offshore wind farm, a corresponding junction double-bus 12 in the offshore wind farm bus system 5, a corresponding junction double-bus longitudinal outgoing line 11 in the longitudinal output u section 4 of the offshore wind farm, and a corresponding VSC (left and right) 8 in the VSC cluster frequency division/low frequency power grid side 3. Two output paths of the ring network of each adjacent wind power plant virtual generator 14 correspond to the transverse direction of the junction double buses 12 in the offshore wind power bus type system 5, and the upper buses and the lower buses are connected by cables 10 connected in the transverse direction between the junction double buses (hot standby connection between each double bus).
Offshore crossover/low frequency grid 9 (fig. 3), comprising: two longitudinal output lines of each wind power plant virtual generator 14 looped network are respectively a corresponding junction double-bus longitudinal incoming line 13 in a longitudinal output d section 6 of the offshore wind farm, a corresponding junction double-bus longitudinal outgoing line 11 in a longitudinal output u section 4 of the offshore wind farm, and a plurality of junction double-buses 12 and a plurality of junction double-bus transverse connecting lines 10 in the offshore wind farm bus system 5; the adjacent hub double buses 12 in the offshore wind power bus type system 5 are connected with each other in the transverse direction, and are respectively connected with each other by a transverse connecting cable 10 (hot standby connection between each double bus) between the hub double buses through the upper bus and the lower bus of the plurality of adjacent hub double buses 12.
The offshore frequency division/low-frequency power transmission network 9 (figure 3), the offshore wind power bus type system 5 (figure 2) and the wind power plant virtual generator 14 (figure 4) adopt the conventional frequency division 161/3 Hz based on the rated frequency of the offshore frequency division/low- frequency power network 15, 80% of p.u. cable capacity can transmit power for a distance of 270km, and can meet the requirements of offshore wind power transmission of deep and far seas of 70-150km in the longitudinal direction and 200 + 120km in the transverse direction in an offshore region. The low-frequency power transmission distance 440km of low-frequency 10Hz and 80% p.u. cable capacity is adopted based on the rated frequency of the offshore frequency division/low-frequency power grid 15, and the requirements of offshore wind power transmission of deep and far sea with the longitudinal length of 70-200km and the transverse length of 370-240km in an offshore area can be met. Therefore, by utilizing the characteristics of frequency division/low-frequency alternating-current long-distance power transmission, the medium-voltage direct-distribution double-fed wind generating set 21 is obtained by interconnecting the offshore frequency division/low-frequency power grid 15, the longitudinal and transverse power transmission distance on the sea or on the land can be further expanded, and the deep and remote sea wind power can be effectively transmitted to the load center of the onshore 50Hz power grid 1 in a long distance.
Each wind power plant virtual generator 14 in the offshore frequency division/low frequency transmission network 9 has the maximum power simultaneously less than or equal to 85% pu. capacity (installed capacity of a wind power plant wind power unit of 1 pu.), is connected to a junction double-bus 12 in an offshore wind power bus type system 5 of the corresponding frequency division/low frequency transmission network 9 through a looped network two-way output junction double-bus longitudinal incoming line 13, is then output through a junction double-bus longitudinal outgoing line 11, has the two-way longitudinal net surfing less than or equal to 50% p.u. capacity, and is respectively connected to the shore VSC (left and right) 8 frequency division/low frequency power network side, in addition, two-way transverse output power on two sides of the junction double-bus 12 is more than or equal to 35% p.u. capacity, and is respectively connected to the shore VSC (left side, right side, and two-way junction double-bus longitudinal outgoing line 11 (total less than or equal to 50% p.u.) through other wind power plants, Right path) 8-division/low-frequency grid side; the cost of the power transmission and transformation equipment of the network access above the offshore wind power bus system 5 (frequency division/low-frequency power grid 15) can be saved by 40%. The shore VSC (left and right) 8 frequency division/low frequency power grid side can coordinate with same frequency and same voltage regulation, and the 50Hz power grid side of the VSC (left and right) 8 coordinates with land 50Hz power grid 1 frequency modulation and voltage regulation to participate in active power and reactive power regulation and coordinate with primary frequency regulation. Based on the frequency division/low frequency transmission network 9 and the wind power plant virtual generator 14, the wind power plant virtual generator has a two-layer high-voltage collecting ring network and medium-voltage collecting ring network structure with high cost performance, high safety and reliability; the adjacent wind power generation units 29 in the wind power plant virtual generator 14 are connected with the medium-voltage direct-distribution double-fed wind power generator set 21 at the tail end of the similar group; and the wind power generation unit 29 has a fault in the head-tail outlet loop of the medium-voltage direct-distribution double-fed wind power generator set 21, so that the island micro-grid can be connected and operated.
An offshore wind farm virtual generator cluster 7 comprising: the system comprises n wind power plant virtual generators 14, wherein each wind power plant virtual generator 14 is provided with a plurality of generating units 29 and a plurality of boosting high-impedance transformers 19, and each generating unit 29 is provided with a plurality of medium-voltage direct-distribution doubly-fed wind power generation sets 21.
The offshore wind farm hub double-bus longitudinal incoming line 13 faces a plurality of high-voltage current collecting ring main units 20, high-voltage current collecting cables 16 and wind farm power generation units 29 and can be equivalent to a wind farm virtual generator 14.
The wind power plant power generation unit 29 in the wind power plant virtual generator 14 is divided into two paths and is connected with one medium-voltage direct-distribution double-fed wind turbine generator 21 through the medium-voltage power collection cable 18 and the medium-voltage power collection ring main unit 17, the power generation power is boosted to the high-voltage power collection ring main unit 20 through the medium-voltage power collection cable 18, the medium-voltage power collection ring main unit 17 and the boosting high-impedance transformer 19, and the power generation power is divided into two paths through the high-voltage power collection ring main unit 20 and is output to the high-voltage power collection cable 16 of the two paths of the ring main units. After the power generated by the virtual generator 14 in the wind farm is generated by the plurality of wind farm power generation units 29, the generated power is output to the upper bus and the lower bus of the double-bus 12 of the junction in the offshore wind power bus system 5 through the looped network two-way high-voltage power collection looped network cabinet 20 and the high-voltage power collection cable 16.
The input side of the high-voltage current collection ring main unit 20 inside the offshore wind farm virtual generator 14 faces the boost high-impedance transformer 19, the plurality of medium-voltage current collection cables 18, the medium-voltage current collection ring main unit 17 and the medium-voltage direct-distribution doubly-fed wind turbine generator 21, and is equivalent to a wind farm power generation unit 29 (fig. 8).
The wind power generation unit 29 of the wind farm can also adopt a two-mode operation mode to realize the wide rotating speed range operation of the medium-voltage direct-distribution double-fed wind turbine generator 21.
The medium-voltage direct distribution doubly-fed wind turbine generator 21 is composed of a doubly-fed converter 22, a direct-drive doubly-fed generator 23 (rated frequency of power transmission network is low frequency) or a semi-direct-drive doubly-fed generator 24, a gear box 25 (rated frequency of power transmission network is frequency division), a hub 26, blades 27, a rotor circuit transformer 28 and a generating unit 29.
When the rated frequency of the offshore frequency division/low-frequency power grid 15 is frequency division, the medium-voltage direct-matching doubly-fed wind generating set 21 adopts a semi-direct-drive doubly-fed generator 24, and when the rated frequency of the offshore frequency division/low-frequency power grid 15 is low frequency, the medium-voltage direct-matching doubly-fed wind generating set 21 adopts a direct-drive doubly-fed generator 23.
And (3) performing synchronous f/V and/or P/V regulation operation regulation on the VSC (left path and right path) 8 frequency division/low-frequency power grid side of the VSC cluster 2. Referring to fig. 3, an operation method of a medium-voltage direct-distribution double-fed wind turbine generator system 21 obtained by interconnecting an offshore frequency division/low-frequency grid 15 is disclosed, wherein a VSC cluster 2 is composed of n sets of VSCs (left and right) 8, each set of VSCs (left and right) 8 is composed of left and right VSCs, each set of VSCs (left and right) frequency division/low-frequency grid side 3 corresponds to an offshore frequency division/low-frequency transmission grid 9, each set of VSCs (left and right) 8 corresponds to a 50Hz grid 1, and each set of VSCs (left and right) 8 is composed of direct-current commutation links.
According to the requirement of the distribution of the wind power generation flow of an offshore frequency division/low-frequency transmission network 9, the terminal voltage of the VSC cluster 2 at the frequency division/low-frequency network side of n groups of VSCs (left and right) 8 can be regulated singly or in a cluster manner, namely, the synchronous f/V or P/V regulation and control of a medium-voltage direct-distribution double-fed wind turbine generator in a wind power plant virtual generator cluster are realized; according to the wind power generation flow distribution of the offshore frequency division/low-frequency transmission network 9 and the requirement of the 50Hz power grid 1 on the Internet, the voltage at the side end of the 50Hz power grid of the VSC (left path and right path) 8 can be regulated singly or in a cluster manner; when the frequency division/low-frequency power input of each VSC (left and right) 8 and the 50Hz power output of the VSC (left and right) 8 are balanced, the power balance must be ensured.
According to the operation method, the operation curve of the medium-voltage direct-distribution double-fed wind turbine generator 21 (for the VSC cluster frequency division/low-frequency grid side 3, the junction double-bus longitudinal outgoing line 11, the offshore wind power bus system 5, the junction double-bus longitudinal incoming line 13 and the wind power plant virtual generator cluster 7, 2n VSCs (left circuit and right circuit) 8 frequency division/low-frequency grid side in the VSC cluster frequency division/low-frequency grid side 3 are utilized to complete synchronous frequency cluster regulation and single or cluster regulation of synchronous voltage of the medium-voltage direct-distribution double-fed wind turbine generator 21 obtained by interconnection of the offshore frequency division/low-frequency grid 15.
As shown in fig. 9, according to wind conditions of a wind power plant in an offshore area, when the wind speed is low in a light wind period, synchronous f/V adjustment of the VSC (left and right) 8-frequency division/low-frequency power grid side is performed; at a divided/low frequency nominal frequency fL/FThe medium-voltage direct-distribution doubly-fed wind turbine generator 21 operates below a point 5, namely the synchronous rotating speed
Following, generator speed n as point 3m3The rated frequency f of the offshore frequency division/low-frequency power grid can be adjusted downL/FTo
The synchronous speed is reduced from point 5 to point 4, the synchronous speed being at this time
Become into
The electric slip is reduced, and the power generation output power of the stator loop is relatively improvedThe method has the advantages of reducing the feedback power of the rotor loop, reducing the system voltage, namely reducing the outlet voltage of the doubly-fed generator, the voltage of the excitation loop and the excitation loss, improving the efficiency and high voltage ride through capability in low wind speed and widening the power generation working range in a low wind speed area.
As shown in fig. 9, according to wind conditions of a wind power plant in an offshore area, when the wind speed is low in a light wind period, synchronous f/V adjustment of the VSC (left and right) 8-frequency division/low-frequency power grid side is performed; at a divided/low frequency nominal frequency fL/FThe medium-voltage direct-distribution double-fed wind turbine generator 21 operates above a point 5, namely the synchronous rotating speed
Above, generator speed n as point 7m7Can increase the rated frequency fL/FTo
The synchronous speed is increased from point 5 to point 6, the synchronous speed being increased from
Become into
The electric slip is reduced, the power generation output power of the stator loop is relatively improved, and the feedback power of the rotor loop is relatively reduced.
Referring to fig. 9, according to wind conditions of a wind power plant in an offshore area, in a high wind speed period, a medium-voltage direct-distribution doubly-fed wind turbine generator 21 operates between a point 8 and a rated operation point 9, and a rotating speed nm8And nm9(nm.n) In between, VSC (left and right) 8 frequency division/low frequency power grid side synchronous P/V regulation can be carried out; the 9 point is a rated operation point 9, and the medium-voltage direct distribution double-fed wind turbine generator 21 is at a rated rotating speed nm.n(nm9) Rated power 100% p.u., rated voltage 100% p.u., rated frequency fL/FThe operation is carried out.
The offshore frequency division/low frequency power grid 15 is interconnected to obtain a medium-voltage direct distribution double-fed wind generating set 21, and the offshore frequency division/low frequency power grid 15 comprises a VSC cluster frequency division/low frequency power grid side 3, an offshore frequency division/low frequency power transmission grid 9 and any wind farm virtual generator i in a wind farm virtual generator cluster 7, and can meet the safety criterion of 'N-1' of a power grid.
Any input and output line of a VSC cluster 2 in an offshore frequency division/low-frequency power grid 15 (figure 3) or a left VSC or a right VSC in a VSC (left or right) 8 fails, and a fault loop can be cut off through an output switch of a high-voltage switch cabinet on the shore; if the operation capacity is overloaded, the medium-voltage direct-distribution doubly-fed wind turbine generator 21 of the corresponding wind power plant needs to be uniformly unloaded to operate, or the offshore frequency division/low-frequency wind power transmission network 9 (the offshore wind power bus system 5) is coordinated, redundant power generation load is transferred to the double-path internet-surfing hub double-bus longitudinal outgoing line 11 with lighter loads of other loops, and finally, redundant power is subjected to internet surfing through other light-load VSCs (left path and right path) 8.
Any input/output line failure and switch failure in the offshore crossover/low frequency power grid 15 can be achieved by cutting out the faulty loop or switch and merging the faulty loop or switch into another loop or bus in normal operation through the hot or cold spare interconnection switch.
As shown in fig. 2, fig. 3 and fig. 4, any loop cable of the double-circuit hub double-bus longitudinal incoming line 13 or the double-circuit hub double-bus longitudinal outgoing line 11 fails, a fault cable loop is cut off through a switch on a shore-on-grid high-voltage cabinet or a hub double-bus 12, or a marine frequency division/low-frequency wind power transmission network 9 (an offshore wind power bus system 5) is coordinated, redundant power generation loads are transferred to the double-circuit on-grid hub double-bus longitudinal outgoing line 11 with lighter loop loads, and finally, redundant power is on the grid through other light-load VSCs (left and right) 8.
Any fault in the longitudinal incoming line 13 of the junction double bus is removed through a switch on the junction double bus 12 in the offshore wind power bus system 5 and a bus switch of the high-voltage collecting ring main unit 20, redundant power generation load of a looped network double-line outgoing high-voltage collecting cable 16 is transferred to another normally-operated double-line outgoing high-voltage collecting cable 16, and when the power generation load of the outgoing high-voltage collecting cable 16 of the wind power plant virtual generator 14 is overloaded, unified load reduction and quota operation are required.
As shown in fig. 4, 5, 6, 7, and 8, in the wind farm virtual generator 14,
1) when a bus or switch fault of the high-voltage current collection ring main unit 20 occurs, two paths of medium-voltage direct-distribution double-fed wind turbine generators 21 in the wind turbine generator units 29 of the current high-voltage current collection ring main unit 20 output power generation loads by cutting off upper, lower, left and right switches, the tail sections of the two paths of medium-voltage direct-distribution double-fed wind turbine generators are connected with the tail sections of other wind turbine generator units 29 of the same transformer group in the wind power plant and then output in a transfer mode, and when the power generation loads of the wind turbine generator units 29 are overloaded, the two paths of medium-voltage direct-distribution double-fed wind turbine generators need to be uniformly unloaded and limited; the virtual generator 14 of the wind power plant generates power load, redundant power load is transferred by disconnecting two ways or one way of the two ways of the two-way junction double-bus longitudinal incoming line 13 of the ring network, and when overload occurs, the unified load reduction and quota operation are needed.
2) When the high-voltage collecting cable 16 has a fault, the input and output switches connected with the high-voltage collecting ring main unit 20 before and after the fault is cut off do not influence the operation of the wind power generation units 29 on both sides of the two-way high-voltage collecting cable 16 of the ring main unit, and if other high-voltage collecting cables 16 are overloaded, the corresponding wind power generation units 29 need to be uniformly unloaded and limited in operation.
3) When the boosting high-impedance transformer 19 in the wind power generation unit 29 has a fault, the upper switch, the lower switch, the left switch and the right switch are cut off, the generation load output by the two paths of medium-voltage direct-distribution double-fed wind power generation sets 21 in the current wind power generation unit 29 is transferred and output after being connected with the tail sections of other internal transformers and the tail sections of the wind power generation units 29 in the same group, and when the generation load is overloaded, the wind power generation units 29 are required to uniformly reduce the load and limit the rated operation.
4) When the medium-voltage collecting cable 18 in the wind power generation unit 29 has a fault, the power generation load output by the medium-voltage direct-distribution double-fed wind power generation unit 21 in the link in the current wind power generation unit 29 is connected and transferred to be output through the tail section and the tail section of other wind power generation units 29 by cutting off the upper, lower, left and right switches, and when the power generation load is overloaded, the medium-voltage direct-distribution double-fed wind power generation unit 21 in the link needs to be uniformly unloaded and limited in running.
5) The medium-voltage current collection ring main unit 17 in the wind power generation unit 29 has a fault, other medium-voltage direct-distribution double-fed wind power generation units 21 which cannot output the medium-voltage loop in the ring network output power generation loads through the upper, lower, left and right switches, the tail sections of the medium-voltage direct-distribution double-fed wind power generation units and the tail sections of other wind power generation units 29 are connected and transferred to output the generated loads, and when the generated loads are overloaded, the medium-voltage direct-distribution double-fed wind power generation units 21 need to be uniformly unloaded and operated in a limited amount. And the medium-voltage direct-distribution double-fed wind turbine generator 21 output by the corresponding fault medium-voltage current collection ring main unit 17 can only rotate to the lower isolated island operation.
As shown in fig. 4, 5, 6, 7 and 8, a single medium-voltage direct-distribution doubly-fed wind turbine generator 21 in the wind farm virtual generator 14 is operated in an isolated island mode.
The medium-voltage direct-distribution double-fed wind turbine generator 21 in the wind power generation unit 29 in the wind power plant virtual generator 14 is characterized in that if a medium-voltage collection ring main unit 17 has an internal fault, a normal power generation output channel is disconnected and cannot normally operate, the medium-voltage direct-distribution double-fed wind turbine generator 21 can adopt an internal small-power isolated network operation mode, and the medium-voltage direct-distribution double-fed wind turbine generator 21 operates in an isolated island mode in small-power generation operation under the condition that the dynamic static stability of a voltage range and a frequency range is met.
Therefore, the offshore frequency division/low frequency power grid 15, i.e. the offshore frequency division/low frequency power transmission grid 9 and the virtual generator cluster 7, the VSC cluster frequency division/low frequency power grid side 3, the left VSC and the right VSC of any onshore VSC (left and right) 8, the cable of the junction double-bus longitudinal outgoing line 11, the junction double-bus 12, the cable of the junction double-bus longitudinal incoming line 13, the cable of the junction double-bus transverse connection line 10, the high voltage collecting cable 16, the high voltage collecting ring main unit 20, the boosting high-resistance transformer 19, the medium voltage collecting cable 18 and the medium voltage collecting ring main unit 17 are failed, after the failed equipment is removed, the wind farm generating power is transmitted to the internet through a hot or cold spare line, and the normal generating operation of the offshore frequency division/low frequency power transmission grid 9, the virtual generator cluster 7 and the VSC cluster frequency division/low frequency power grid side 3 is ensured. The wind power generation unit 29 in the wind power plant virtual generator 14 generates power by adopting two medium voltage current collection ring main units 17 of a ring network, a medium voltage current collection cable 18 is connected with the network, the tail end of the medium voltage current collection cable is connected with other wind power generation units 29 for hot or cold standby, and a double-bus longitudinal incoming line 13 of a double-way junction of the ring network is connected with the network through a high voltage current collection ring main unit 20; adjacent offshore hub double buses 12 in the offshore wind power bus type system 5 are transversely connected through upper buses/upper buses and lower buses/lower buses, hot standby connecting lines are arranged in the hub double buses 12, and a longitudinal double-road shore is respectively connected with a left VSC and a right VSC frequency division/low frequency grid side in a VSC (left road and right road) 8; the offshore frequency division/low frequency power grid 15 comprises an offshore wind farm virtual generator cluster 7, a frequency division/low frequency power transmission grid 9 and a VSC cluster frequency division/low frequency power grid side 3, and the operation requirements of the 'N-1' safety criterion are really met.
The wind power generation unit 29 of the wind power plant adopts a boosting high-impedance transformer 19, and is cooperated with the output reactive power of the medium-voltage direct-distribution double-fed wind power generator set 21, so that the voltage deviation of the medium-voltage direct-distribution double-fed wind power generator set 21 on the internet can be adjusted, and the steady-state and dynamic operation of a wide rated voltage range, high voltage ride through and low voltage ride through range can be participated; meanwhile, the rated voltage range and the high voltage ride through and low voltage ride through ranges can be widened. The percentage value of the impedance voltage of the step-up high impedance transformer 19 is selected udT％＝12～36。
The invention is based on the wind generating set operation method of the offshore wind power bus system, when the rated frequency of the offshore frequency division/low frequency power grid 15 is 50/3 +/-5% Hz of frequency division, adopt the semi-direct drive type double-fed generator 24, take the first class or second gear box 25; the rated frequency of the offshore crossover/low frequency power grid 15 is 10 +/-17% Hz at low frequency, and a direct-drive doubly-fed generator 23 is adopted without a gearbox 25. The rated voltage range of the rotor is 0.69 kV-10 kV, the rated voltage range of the stator is 0.69 kV-35 kV, and the capacity range of the generator set is 5 MW-50 MW.
The foregoing basic embodiments of the invention and their various further alternatives can be freely combined to form multiple embodiments, all of which are contemplated and claimed herein. In the scheme of the invention, each selection example can be combined with any other basic example and selection example at will. Numerous combinations will be known to those skilled in the art.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.
Claims (6)
1. A wind generating set operation method based on an offshore wind power bus system is characterized by comprising the following steps:
when the rated frequency of the offshore wind power generation bus type system is 50/3 +/-5 percent Hz, the medium-voltage direct-matching semi-direct-drive double-fed generator is adopted, and when the rated frequency of the offshore wind power generation bus type system is 10 +/-17 percent Hz, the medium-voltage direct-matching direct-drive double-fed generator is adopted.
2. The method for operating the wind generating set based on the offshore wind power bus-type system according to claim 1, wherein the wind power plant virtual generators of a plurality of offshore adjacent wind power plants enter the wind power plant virtual generators longitudinally through a hub double bus of the wind power plant virtual generators; and the upper bus and the lower bus in the plurality of adjacent hub double buses are respectively connected by a transverse connecting line between the hub double buses to form an offshore wind power bus system of the offshore frequency division/low-frequency power grid.
3. The method of claim 1, wherein the offshore crossover/low frequency grid comprises: the method comprises the following steps that (1) the frequency division/low frequency power transmission network side of an offshore wind farm virtual generator cluster, the frequency division/low frequency power grid side of a VSC cluster;
two-way longitudinal outgoing line output of each wind power plant virtual generator ring network in the offshore wind power plant virtual generator cluster is connected with the Internet from the VSC cluster frequency division/low frequency power grid side through the offshore frequency division/low frequency power transmission network.
4. The method of claim 3, wherein the offshore wind energy bus system based wind turbine generator system comprises two longitudinal output lines for each wind farm virtual generator ring network.
5. The method for operating the wind generating set based on the offshore wind power bus system according to claim 4, wherein the offshore wind farm virtual generator cluster comprises a plurality of wind farm virtual generators, each wind farm virtual generator comprises a plurality of generating units and a plurality of boosting high-impedance transformers, and each generating unit comprises a plurality of medium-voltage direct-distribution doubly-fed wind generating sets.
6. The method for operating the wind generating set based on the offshore wind power bus-type system according to claim 5, wherein the wind power generating unit adopts a boost high-impedance transformer to regulate the grid voltage deviation of the medium-voltage direct-distribution double-fed wind generating set in cooperation with the output reactive power of the medium-voltage direct-distribution double-fed wind generating set.
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Address after: 618099 No.99, Zhujiang East Road, Jingyang District, Deyang City, Sichuan Province Applicant after: Dongfang Electric Wind Power Co.,Ltd. Address before: 618099 No.99, Zhujiang East Road, Jingyang District, Deyang City, Sichuan Province Applicant before: DONGFANG ELECTRIC WIND POWER Co.,Ltd. |
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