Wind power generation system and wind power generation main system

Abstract

The utility model provides a wind power generation system and a wind power generation main system. The wind power generation system comprises a doubly-fed generator and a doubly-fed converter unit; the doubly-fed generator comprises a plurality of winding pairs; each winding pair comprises a rotor winding and a stator winding; each winding pair is provided with a corresponding branch; one end of the branch is connected with the winding pair and the other end is connected with a power grid; a doubly-fed converter unit is arranged on the branch; the rotor winding in the winding pair is connected with the first side of the double-fed converter unit, and the stator winding in the winding pair is connected with the second side of the double-fed converter unit; the second side is connected with a power grid; and the branches of different winding pairs are mutually independent. According to the mode, the model selection requirements of devices and circuits of the double-fed converter unit are reduced, and meanwhile, the redundancy and the reliability of a power generation system are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of wind power, in particular to a wind power generation system and a wind power generation main system. Background Art

[0002] The wind power generation system mainly includes a doubly-fed generator and a doubly-fed converter. The doubly-fed generator usually includes a winding, which is connected to the doubly-fed converter; the electric energy generated by the winding operation is converted by the doubly-fed converter and then input into the power grid. When a winding in the doubly-fed converter or doubly-fed generator fails, the wind power generation system as a whole loses its power generation capacity, resulting in low reliability of the wind power generation system. Utility Model Content

[0003] In view of this, an object of the present invention is to provide a wind power generation system and a wind power generation main system to improve the redundancy and reliability of the power generation system.

[0004] In a first aspect, an embodiment of the utility model provides a wind power generation system, which includes a doubly fed generator and a doubly fed converter unit; the doubly fed generator includes multiple pairs of winding pairs; each pair of winding pairs includes a rotor winding and a stator winding; each pair of winding pairs is provided with a corresponding branch; one end of the branch is connected to the winding pair, and the other end is connected to the power grid; a doubly fed converter unit is provided on the branch; the rotor winding in the winding pair is connected to the first side of the doubly fed converter unit, and the stator winding in the winding pair is connected to the second side of the doubly fed converter unit; the second side is also connected to the power grid; the branches provided with different winding pairs are independent of each other.

[0005] In the above branch, a first on-off control device is provided between the first side of the doubly-fed converter unit and the rotor winding.

[0006] In the above branch, a second on-off control device is provided between the second side of the doubly-fed converter unit and the stator winding; and a third on-off control device is provided between the second side of the doubly-fed converter unit and the power grid.

[0007] The third on-off control device is arranged between the power grid and the second on-off control device.

[0008] The doubly-fed converter units arranged on the above branches are doubly-fed converters, and the doubly-fed converters on different branches are independent of each other; or, the doubly-fed converter units arranged on different branches are integrated in the same doubly-fed converter, and the doubly-fed converter units on different branches are independent of each other in the lines.

[0009] The above-mentioned wind power generation system also includes a grid transformer; the first side of the grid transformer is connected to the grid, and the second side of the grid transformer includes multiple winding structures, each winding structure corresponds to a branch; each winding structure is connected to the double-fed converter unit in the corresponding branch.

[0010] The above-mentioned wind power generation system also includes a grid transformer; the first side of the grid transformer is connected to the grid, and the second side of the grid transformer includes a winding structure; the branches corresponding to the multiple pairs of winding pairs are respectively connected to the winding structure.

[0011] The branch in which each pair of winding pairs is arranged includes a plurality of double-fed current conversion units; and the plurality of double-fed current conversion units in the same branch are connected in parallel.

[0012] The above-mentioned doubly-fed converter unit includes an AC / DC conversion unit and a DC / AC conversion unit; a DC bus is connected between the AC / DC conversion unit and the DC / AC conversion unit; and the DC buses of the doubly-fed converter units corresponding to different winding pairs are independent of each other.

[0013] In the second aspect, an embodiment of the utility model provides a main wind power generation system, which includes: a wind power generation system, a system control device and a communication control module; multiple double-fed converter units in the wind power generation system are all connected to the communication control module, and the communication control module is connected to the system control device.

[0014] The embodiments of the present invention bring the following beneficial effects:

[0015] The above-mentioned wind power generation system and wind power generation main system, the wind power generation system includes a doubly fed generator and a doubly fed converter unit; the doubly fed generator includes multiple pairs of winding pairs; each pair of winding pairs includes a rotor winding and a stator winding; each pair of winding pairs is provided with a corresponding branch; one end of the branch is connected to the winding pair, and the other end is connected to the power grid; a doubly fed converter unit is arranged on the branch; the rotor winding in the winding pair is connected to the first side of the doubly fed converter unit, and the stator winding in the winding pair is connected to the second side of the doubly fed converter unit; the second side is also connected to the power grid; the branches arranged in different winding pairs are independent of each other.

[0016] In this method, the doubly-fed generator is provided with multiple pairs of winding pairs, and each pair of winding pairs is provided with a corresponding branch, in which a doubly-fed converter unit is provided. The branches connected by different winding pairs are independent of each other. Multiple winding pairs and doubly-fed converter units can share the power generation of the doubly-fed generator, reducing the selection requirements of the devices and lines of the doubly-fed converter units. At the same time, when a winding pair or branch of a certain line fails, the other winding pairs and the corresponding branches can work normally, thereby improving the redundancy and reliability of the power generation system.

[0017] Other features and advantages of the utility model will be described in the following description, and partly become apparent from the description, or understood by practicing the utility model. The purpose and other advantages of the utility model are realized and obtained by the structures specifically pointed out in the description, claims and drawings.

[0018] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are some implementation methods of the utility model. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 A schematic diagram of the structure of a wind power generation system provided by an embodiment of the utility model;

[0021] Figure 2 A schematic diagram of the circuit connection of a first wind power generation system provided by an embodiment of the utility model;

[0022] Figure 3 A schematic diagram of line connection of a second wind power generation system provided in an embodiment of the utility model. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the embodiments of the utility model clearer, the technical solution of the utility model will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0024] In wind power generation systems, the power of wind turbines is increasing, and the reliability and redundancy of power generation systems are becoming more important. Especially in offshore wind power generation scenarios, the power of wind turbines is very large, and the daily maintenance of equipment is constrained by wind conditions. When equipment fails, the staff cannot go out to sea in time for fault operation and maintenance, so the equipment needs to have high reliability and redundancy to ensure the normal operation of the power generation system.

[0025] The current doubly-fed wind turbine generator is a single-winding structure, that is, the doubly-fed wind turbine generator contains a set of stator windings and rotor windings, and the doubly-fed converter unit connected to the doubly-fed wind turbine generator also only supports single-winding connection and does not have redundant operation capabilities. When any device or component in the doubly-fed converter and doubly-fed generator fails, the wind power generation system as a whole loses its power generation capacity, resulting in low reliability of the wind power generation system.

[0026] Based on the above problems, this embodiment provides a wind power generation system and a wind power generation main system, which can be applied in the wind power field.

[0027] First, see Figure 1 A structural schematic diagram of a wind power generation system is shown; the wind power generation system includes a double-fed generator 10 and a double-fed converter unit; the double-fed generator includes a plurality of winding pairs; each winding pair includes a rotor winding and a stator winding; Figure 1 In the example of , the doubly-fed generator includes three pairs of winding pairs, namely winding pair 101, winding pair 102 and winding pair 103; each pair of winding pairs includes a rotor winding and a stator winding. This embodiment does not specifically limit the number of winding pairs.

[0028] Each pair of winding pairs is provided with a corresponding branch; one end of the branch is connected to the winding pair, and the other end is connected to the power grid; a double-fed converter unit is provided on the branch; the rotor winding in the winding pair is connected to the first side of the double-fed converter unit, and the stator winding in the winding pair is connected to the second side of the double-fed converter unit; the second side is also connected to the power grid.

[0029] exist Figure 1 In the example, winding pair 101 corresponds to the doubly fed converter unit 201, winding pair 102 corresponds to the doubly fed converter unit 202, and winding pair 103 corresponds to the doubly fed converter unit 203; wherein the rotor winding of winding pair 101 is connected to the first side of the doubly fed converter unit 201, and the stator winding of winding pair 101 is connected to the second side of the doubly fed converter unit 201; wherein the first side is also called the motor side, and the second side is also called the grid side.

[0030] Similarly, the rotor winding of winding pair 102 is connected to the first side of the doubly fed converter unit 202, and the stator winding of winding pair 102 is connected to the second side of the doubly fed converter unit 202; the rotor winding of winding pair 103 is connected to the first side of the doubly fed converter unit 203, and the stator winding of winding pair 103 is connected to the second side of the doubly fed converter unit 203.

[0031] It should be noted that the present embodiment does not specifically limit the number of doubly-fed converter units, but the number of doubly-fed converter units is generally related to the number of winding pairs, and the number of branches is also related to the number of winding pairs. For example, each winding pair is connected to at least one doubly-fed converter unit, and a winding pair can also be connected to multiple doubly-fed converter units. The doubly-fed converter units connected to the same winding pair are connected in parallel; the doubly-fed converter units of different winding pairs are independent of each other.

[0032] The branches set by different winding pairs are independent of each other, that is, the doubly-fed converter units set by different winding pairs are independent of each other. In this embodiment, the lines and devices between the doubly-fed converter unit 201, the doubly-fed converter unit 202 and the doubly-fed converter unit 203 are independent of each other, and the different doubly-fed converter units do not share devices and there are no lines connected to each other. The remote system control device can independently control the different doubly-fed converter units.

[0033] In one mode, the aforementioned doubly-fed converter unit can be specifically a doubly-fed converter, that is, a doubly-fed converter is provided in each branch, and the doubly-fed converters in different branches are independent of each other. In another mode, the doubly-fed converter units in different branches can be integrated into one doubly-fed converter, but the doubly-fed converter units in different branches are independent of each other in the line, and the doubly-fed converter units in different branches are only integrated in one cabinet.

[0034] There is another way, when there are many branches in the wind power generation system, each branch in a part of the branches can be provided with a separate double-fed converter, and the other part of the branches can use a double-fed converter, but the double-fed converter units corresponding to each branch are independent of each other. For example, when there are three branches in the wind power generation system, the double-fed converter units in branches 1 and 2 share a double-fed converter, and the two double-fed converter units in the double-fed converter are independent in line; the double-fed converter unit in branch 3 uses a single double-fed converter.

[0035] The above-mentioned wind power generation system includes a doubly fed generator and a doubly fed converter unit; the doubly fed generator includes multiple pairs of winding pairs; each pair of winding pairs includes a rotor winding and a stator winding; each pair of winding pairs is provided with a corresponding branch; one end of the branch is connected to the winding pair, and the other end is connected to the power grid; a doubly fed converter unit is provided on the branch; the rotor winding in the winding pair is connected to the first side of the doubly fed converter unit, and the stator winding in the winding pair is connected to the second side of the doubly fed converter unit; the second side is also connected to the power grid; the branches provided with different winding pairs are independent of each other.

[0036] In this method, the doubly-fed generator is provided with multiple pairs of winding pairs, and each pair of winding pairs is provided with a corresponding branch, in which a doubly-fed converter unit is provided. The branches connected by different winding pairs are independent of each other. Multiple winding pairs and doubly-fed converter units can share the power generation of the doubly-fed generator, reducing the selection requirements of the devices and lines of the doubly-fed converter units. At the same time, when a winding pair or branch of a certain line fails, the other winding pairs and the corresponding branches can work normally, thereby improving the redundancy and reliability of the power generation system.

[0037] For a specific implementation, see Figure 2 A schematic diagram of the line connection of a wind power generation system is shown in FIG. Figure 2In the example, the doubly fed generator takes the DFIG generator as an example. The full name of DFIG is Doubly fed Induction Generator, and its Chinese name is doubly fed asynchronous wind turbine.

[0038] Figure 2 The doubly-fed generator in the embodiment includes two pairs of winding pairs, wherein the rotor winding 1 and the stator winding 1 form a pair of winding pair 1, and the rotor winding 2 and the stator winding 2 form a pair of winding pair 2. The winding pair is connected to the doubly-fed converter unit 1, and the winding pair 2 is connected to the doubly-fed converter unit 2; GRID is a power grid.

[0039] In the above branch, a first on-off control device is provided between the first side of the double-fed converter unit and the rotor winding. The first on-off control device may be a circuit breaker or other switch device. Figure 2 In the embodiment, QF2 is arranged between the rotor winding 1 and the doubly-fed converter unit 1; QF4 is arranged between the rotor winding 2 and the doubly-fed converter unit 2; QF2 and QF4 are circuit breakers with current breaking capability.

[0040] In the above branch, a second on-off control device is provided between the second side of the doubly-fed converter unit and the stator winding, and a third on-off control device is provided between the second side of the doubly-fed converter unit and the power grid. The second on-off control device may be a contactor or other switch device. For example, Figure 2 In the embodiment, KM1 is arranged between stator winding 1 and doubly-fed converter unit 1; KM2 is arranged between stator winding 2 and doubly-fed converter unit 2; KM1 and KM2 are contactors.

[0041] The third on-off control device may be a circuit breaker or other switch device. Figure 2 In the embodiment, QF1 is arranged between the power grid and the double-fed converter unit 1; QF3 is arranged between the power grid and the double-fed converter unit 2; QF1 and QF3 are circuit breakers with current breaking capability.

[0042] Furthermore, since the second on-off control device and the third on-off control device are both connected to the second side of the doubly fed converter unit, in order to control the on-off of the doubly fed converter unit and the winding with respect to the power grid through the third on-off control device, in a specific manner, the third on-off control device is arranged between the power grid and the second on-off control device; and the second on-off control device is arranged between the second side of the doubly fed converter unit and the stator winding.

[0043] by Figure 2 Taking QF1 in FIG. 1 as an example, after QF1 is disconnected, the doubly-fed converter unit 1 and the winding pair 1 are both disconnected from the grid; similarly, after QF3 is disconnected, the doubly-fed converter unit 2 and the winding pair 2 are both disconnected from the grid.

[0044] In another implementation, a first on-off control device, a second on-off control device and a third on-off control device are also provided in the branch; the first on-off control device is connected to the rotor winding in the winding pair corresponding to the branch, and the first on-off control device, the doubly fed converter unit in the branch and the third on-off control device are connected in sequence; the third on-off control device is also connected to the power grid; one end of the second on-off control device is connected to the stator winding in the winding pair corresponding to the branch, and the other end is connected between the third on-off control device and the doubly fed converter unit.

[0045] refer to Figure 2 In the embodiment, the doubly-fed generator includes two pairs of winding pairs, and two branches are set in the system. In the first branch, the first on-off control device is QF2, the doubly-fed converter unit 1 and the third on-off control device QF1 are connected in sequence, and QF1 is also connected to the power grid; the second on-off control device is KM1, one end of KM1 is connected to the stator winding 1, and the other end is connected between QF1 and the double-open converter unit 1.

[0046] In the second branch, the first on-off control device is QF4, the double-fed converter unit 2 and the third on-off control device QF3 are connected in sequence, and QF3 is also connected to the power grid; the second on-off control device is KM2, one end of KM2 is connected to the stator winding 2, and the other end is connected between QF3 and the double-fed converter unit 2.

[0047] Furthermore, the doubly-fed converter unit arranged on the above-mentioned branch is a doubly-fed converter, and the doubly-fed converters on different branches are independent of each other; this method can be understood as a doubly-fed converter being arranged on each branch, that is, a pair of winding pairs corresponds to a doubly-fed converter; the doubly-fed converters on different branches are separated from each other and independently controlled.

[0048] Alternatively, the doubly-fed converter units arranged on different branches are integrated into the same doubly-fed converter, and the doubly-fed converter units on different branches are independent of each other on the line. This method can be understood as that a plurality of doubly-fed converter units are integrated in the doubly-fed converter, and the plurality of doubly-fed converter units are located in the same cabinet, but different doubly-fed converter units are independent of each other on the line, and the doubly-fed converter units are independently controlled and do not affect each other.

[0049] In actual implementation, the above-mentioned wind power generation system also includes a grid transformer; the first side of the grid transformer is connected to the grid, and the second side of the grid transformer includes multiple winding structures, each winding structure corresponds to a branch; each winding structure is connected to the double-fed converter unit in the corresponding branch.

[0050] exist Figure 3 In the description, the grid transformer is explained by taking a multi-winding transformer as an example. The first side of the grid transformer is usually the high-voltage side, connected to the grid; the second side of the grid transformer is usually the low-voltage side, connected to the double-fed converter unit in the corresponding branch; the second side of the grid transformer has multiple winding structures, Figure 3 In the embodiment, since the doubly-fed generator includes two pairs of winding pairs, the grid transformer is provided with two winding structures, one winding structure is connected to the doubly-fed converter unit 1 in the branch corresponding to winding pair 1, and the other winding structure is connected to the doubly-fed converter unit 2 in the branch corresponding to winding pair 2.

[0051] In another implementation, the second side of the grid transformer is a single winding structure. Specifically, the wind power generation system further includes a grid transformer; the first side of the grid transformer is connected to the grid, and the second side of the grid transformer includes a winding structure; the branches corresponding to the plurality of winding pairs are respectively connected to the winding structure.

[0052] The first side of the grid transformer is usually the high-voltage side, connected to the grid; the second side of the grid transformer is usually the low-voltage side, connected to the doubly-fed converter unit in the corresponding branch; the second side includes only one winding structure, and the doubly-fed converter unit of each winding pair is connected to the winding structure via the corresponding third on-off control device.

[0053] The wind power generation system has redundant control capability, and each pair of windings of the doubly-fed generator can be independently connected to the grid for power generation, that is, when a doubly-fed converter unit in the wind power generation system fails, the switch corresponding to the circuit is disconnected. The remaining doubly-fed converter units and corresponding winding pairs can still maintain grid-connected power generation, thereby achieving redundant power generation.

[0054] refer to Figure 2 When a fault occurs in the doubly-fed converter unit 1, QF1, KM1 and QF2 can be controlled to be disconnected, while the doubly-fed converter unit 2 and winding pair 2 can still be connected to the grid and generate electricity normally.

[0055] In a feasible manner, the branch in which each pair of winding pairs is arranged includes a plurality of double-fed converter units; and the plurality of double-fed converter units in the same branch are connected in parallel.

[0056] exist Figure 2 and Figure 3 In the example, only one doubly-fed converter unit is provided in the branch corresponding to each winding pair; multiple doubly-fed converter units can also be provided in the branch corresponding to each winding pair. For example, doubly-fed converter unit 1 and doubly-fed converter unit 3 are provided in winding pair 1. After doubly-fed converter unit 1 and doubly-fed converter unit 3 are connected in parallel, they are respectively connected to rotor winding 1 and stator winding 1 in winding pair 1.

[0057] It should be noted that the doubly-fed generator includes multiple pairs of winding pairs, some of the winding pairs can be provided with only one doubly-fed converter unit, and other parts of the winding pairs can be provided with multiple parallel doubly-fed converter units; another possible method is that each winding pair is provided with multiple parallel doubly-fed converter units.

[0058] The above-mentioned doubly-fed converter unit includes an AC / DC conversion unit and a DC / AC conversion unit; a DC bus is connected between the AC / DC conversion unit and the DC / AC conversion unit; and the DC buses of the doubly-fed converter units corresponding to different winding pairs are independent of each other.

[0059] The AC / DC conversion unit is used to convert alternating current into direct current, and the DC / AC conversion unit is used to convert direct current into alternating current. In a doubly-fed converter unit, the DC bus includes a positive bus and a negative bus. The positive bus is connected between the AC / DC conversion unit and the DC / AC conversion unit. Similarly, the negative bus is connected between the AC / DC conversion unit and the DC / AC conversion unit. The DC buses of the doubly-fed converter units corresponding to different winding pairs are independent of each other. It can be understood that the AC / DC conversion unit and the DC / AC conversion unit between the doubly-fed converter units corresponding to different winding pairs are not connected through the DC bus.

[0060] In the above embodiment, the doubly-fed generator is designed as a multi-winding structure, and the doubly-fed converter unit matched therewith is also designed to support a multi-winding grid-connected structure, which can realize the redundancy performance of the power generation system and improve the reliability of the system.

[0061] In addition, when the rated current of devices such as winding pairs and doubly-fed converter units remains unchanged, the power level of the power generation system can be improved by using multiple pairs of winding pairs and multiple sets of independent doubly-fed converter units. Multiple pairs of winding pairs and multiple sets of independent doubly-fed converter units form multiple independent grid-connected branches, and multiple parallel instructions share the power generation power of the doubly-fed generator, which reduces the difficulty of selecting high-power devices such as converters and improves the reliability of system operation.

[0062] Based on the above-mentioned wind power generation system, this embodiment also provides a wind power generation main system, which includes a wind power generation system, a system control device and a communication control module; multiple double-fed converter units in the wind power generation system are all connected to the communication control module, and the communication control module is connected to the system control device.

[0063] The system control device can send excitation instructions and torque instructions to the double-fed converter unit through the communication control module. In actual implementation, multiple double-fed converter units can be connected to the same communication control module, and the system control device controls the operation of each double-fed converter unit and its corresponding winding pair through the communication control module.

[0064] The system control device can send the total excitation instruction and the total torque instruction through the communication control module. The excitation instruction of the winding pair corresponding to each doubly-fed converter unit is equal to the total excitation instruction divided by the number of winding pairs; the torque instruction of the winding pair corresponding to each doubly-fed converter unit is equal to the total torque instruction divided by the number of winding pairs.

[0065] When a faulty doubly-fed converter unit occurs in the system, the fault information of the doubly-fed converter unit is fed back to the system control device through the communication control module. The system control device adjusts the total excitation command and the total torque command according to the number of faulty doubly-fed converter units, and sends the adjusted total excitation command and the total torque command to the communication control module again, thereby controlling the operation of the normally operating doubly-fed converter units and the corresponding winding pairs.

[0066] In addition, in the description of the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0067] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the utility model can be embodied in the form of a software product in essence or in other words, the part that contributes to the prior art or the part of the technical solution. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the utility model. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0068] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0069] Finally, it should be noted that the above embodiments are only specific implementation methods of the utility model, which are used to illustrate the technical solution of the utility model, rather than to limit it. The protection scope of the utility model is not limited thereto. Although the utility model is described in detail with reference to the above embodiments, those skilled in the art should understand that any technician familiar with the technical field can still modify the technical solution recorded in the above embodiments within the technical scope disclosed by the utility model, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solution deviate from the spirit and scope of the technical solution of the embodiment of the utility model, and should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model shall be based on the protection scope of the claims.

Claims

1. A wind power generation system, characterized in that: The wind power generation system comprises a doubly-fed generator and a doubly-fed converter unit; the doubly-fed generator comprises a plurality of winding pairs; each pair of the winding pairs comprises a rotor winding and a stator winding; Each pair of the winding pairs is provided with a corresponding branch; one end of the branch is connected to the winding pair, and the other end is connected to the power grid; a double-fed converter unit is provided on the branch; the rotor winding in the winding pair is connected to the first side of the double-fed converter unit, and the stator winding in the winding pair is connected to the second side of the double-fed converter unit; the second side is also connected to the power grid; The branches arranged for different winding pairs are independent of each other.

2. The wind power generation system according to claim 1, characterized in that: In the branch, a first on-off control device is provided between the first side of the doubly-fed converter unit and the rotor winding.

3. The wind power generation system according to claim 2, characterized in that: In the branch, a second on-off control device is provided between the second side of the double-fed converter unit and the stator winding; A third on-off control device is provided between the second side of the double-fed converter unit and the power grid.

4. The wind power generation system according to claim 3, characterized in that: The third on-off control device is arranged between the power grid and the second on-off control device.

5. The wind power generation system according to claim 1, characterized in that: The double-fed converter units arranged on the branches are double-fed converters, and the double-fed converters on different branches are independent of each other; Alternatively, the double-fed converter units arranged on different branches are integrated into the same double-fed converter, and the double-fed converter units on different branches are independent of each other in the lines.

6. The wind power generation system according to claim 1, characterized in that: The wind power generation system further comprises a grid transformer; a first side of the grid transformer is connected to the grid, and a second side of the grid transformer comprises a plurality of winding structures, each of the winding structures corresponds to one of the branches; Each of the winding structures is connected to a doubly-fed converter unit in the corresponding branch.

7. The wind power generation system according to claim 1, characterized in that: The wind power generation system further comprises a grid transformer; a first side of the grid transformer is connected to the grid, and a second side of the grid transformer comprises a winding structure; The branches corresponding to the plurality of winding pairs are respectively connected to the winding structure.

8. The wind power generation system according to claim 1, characterized in that: Each pair of the winding pairs includes a plurality of double-fed converter units in the branch; Multiple double-fed converter units in the same branch are connected in parallel.

9. The wind power generation system according to claim 1, characterized in that: The double-fed converter unit includes an AC / DC converter unit and a DC / AC converter unit; a DC bus is connected between the AC / DC converter unit and the DC / AC converter unit; The DC buses of the doubly-fed converter units corresponding to different winding pairs are independent of each other.

10. A main wind power generation system, characterized in that: The main wind power generation system comprises: the wind power generation system according to any one of claims 1 to 9, a system control device and a communication control module; The multiple double-fed converter units in the wind power generation system are all connected to the communication control module, and the communication control module is connected to the system control device.

Images