A method and system for grid-connected coordinated processing of wind turbines with energy storage and inverter

Abstract

The present invention discloses a method and system for grid-connected collaborative processing of wind turbines with energy storage inverters. The method comprises: generating a grid-connected data frame, the grid-connected data frame comprising a main control unit grid-connected status field, a grid parameter field, and a wind turbine unit operating parameter field; sending the grid-connected data frame to each wind turbine unit, and when the wind turbine unit determines that the main control unit grid-connected status field is empty, and determines that its own power parameter is greater than the grid-connected power according to the grid parameter field, filling the voltage parameter, power parameter, and frequency parameter into the corresponding array; selecting the wind turbine unit with the largest voltage parameter and power parameter as the main control unit and grid-connecting, and setting the main control unit grid-connected status field in the grid-connected data frame to the wind turbine unit. Thus, grid-connection can be achieved even when the wind farm is powered off. By setting the main control unit and the collaborative unit, the success rate of grid-connection can be improved, and the problem of being unable to connect to the grid again after grid-connection failure due to insufficient power supply of the energy storage inverter device can be avoided.

Description

Technical Field

[0001] The present invention belongs to the field of wind power generation, and in particular relates to a method and system for grid-connected coordinated processing of wind turbine sets with energy storage and inversion. Background Art

[0002] Traditional wind turbines are connected to the grid only when the grid supplies power to the wind turbines through transmission lines and box transformers. The wind turbines’ main control, converter, yaw and pitch systems are powered to meet the necessary conditions for grid connection. The wind turbine converter works in current source mode. When other conditions such as wind conditions are met, the wind turbines can be connected to the grid. However, when the wind farm is out of power, the wind turbines basically cannot be connected to the grid. This mode of relying on grid power supply to connect to the grid affects the efficiency of the entire wind farm’s dynamic adjustment and grid connection. Summary of the invention

[0003] In order to solve the above problems existing in the prior art, the present invention provides a method and system for grid-connected coordinated processing of wind turbines with energy storage inverters. The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0004] A method for grid-connected coordinated processing of wind turbines with energy storage inverters is applied to a plurality of wind turbines, wherein the wind turbines are connected to a collector busbar through an isolation device, the wind turbines include a main control unit and a plurality of cooperative units, the main control unit is connected to an energy storage inverter device so that the main control unit is powered by the energy storage inverter device before being grid-connected or the main control unit charges the energy storage inverter device after being grid-connected;

[0005] The method includes:

[0006] Generate a grid-connected data frame, the grid-connected data frame includes a master control unit grid-connected status field, a power grid parameter field, and a wind turbine unit operating parameter field; the wind turbine unit operating parameter field includes a plurality of arrays, the number of the plurality of arrays corresponds to the number of wind turbines, and each array includes a grid-connected status parameter, a voltage parameter, a power parameter, and a frequency parameter, wherein the master control unit grid-connected status field is used to characterize whether the master control unit has been determined, and the grid-connected status parameter is used to characterize whether the cooperative unit is connected to the collector bus, when the wind turbine unit is grid-connected, the wind turbine unit operating parameter is an actual measured value, and when the wind turbine unit is not grid-connected, the wind turbine unit operating parameter is an estimated value;

[0007] The grid-connected data frame is sent to each wind turbine group. When the wind turbine group determines that the grid-connected state field of the master control group is empty, and determines that its own power parameter is greater than the grid-connected power according to the grid parameter field, the voltage parameter, power parameter, and frequency parameter are filled into the corresponding array;

[0008] The wind turbine set with the largest voltage parameter and power parameter is selected as the master control set and connected to the grid, and the master control set grid connection state field in the grid connection data frame is set to the wind turbine set.

[0009] In a specific embodiment, when it is determined that the grid-connected status field of the master control unit is not empty, the cooperative unit sends the grid-connected data frame to the microgrid controller every preset period. When the microgrid controller determines that the grid-connected status parameter returned by the cooperative unit is empty and the power parameter of the cooperative unit itself is greater than the grid-connected power of the power grid, the collector bus supplies power to the cooperative unit to connect the cooperative unit to the collector bus.

[0010] In a specific embodiment, when it is determined that the grid-connected status parameter returned by the cooperative unit is not empty and the voltage parameter of the cooperative unit itself is less than a preset percentage of the grid voltage parameter, it is determined whether the voltage of other wind turbines connected to the collector bus is load balanced after compensating for the cooperative unit. If not, the isolation device is controlled to be cut off to allow the cooperative unit to exit the grid.

[0011] In a specific embodiment, the grid-connected data frame also includes a priority grid-connected field, which is used to record the cooperative unit that has exited the grid; the microgrid controller fills the serial number of the cooperative unit that has exited the grid in the priority grid-connected field; when the microgrid controller determines that the cooperative unit meets the grid-connected conditions again, it prioritizes the collector bus to supply power to the cooperative unit to connect the cooperative unit to the collector bus, and deletes the serial number of the cooperative unit from the grid-connected data frame.

[0012] In a specific embodiment, the output voltage and frequency of the cooperative unit are controlled according to the voltage fluctuation of the master unit, so that the voltage output to the collector bus has a fixed voltage and frequency.

[0013] The present invention also provides a wind turbine grid-connected collaborative processing system with energy storage inverter, comprising a plurality of wind turbines, wherein the wind turbines are connected to a collector busbar through an isolation device, the wind turbines include a main control unit and a plurality of cooperative units, the main control unit is connected to an energy storage inverter device so that the main control unit is powered by the energy storage inverter device before being connected to the grid or the main control unit charges the energy storage inverter device after being connected to the grid; the wind turbines are all connected to a microgrid controller;

[0014] The microgrid controller is used to generate a grid-connected data frame, which includes a master control unit grid-connected status field, a power grid parameter field, and a wind turbine unit operating parameter field; the wind turbine unit operating parameter field includes a plurality of arrays, the number of which corresponds to the number of wind turbines, and each array includes a grid-connected status parameter, a voltage parameter, a power parameter, and a frequency parameter, wherein the master control unit grid-connected status field is used to characterize whether the master control unit has been determined, and the grid-connected status parameter is used to characterize whether the cooperative unit is connected to the collector bus, when the wind turbine unit is grid-connected, the wind turbine unit operating parameter is an actual measured value, and when the wind turbine unit is not grid-connected, the wind turbine unit operating parameter is an estimated value;

[0015] The grid-connected data frame is sent to each wind turbine group. When the wind turbine group determines that the grid-connected state field of the master control group is empty, and determines that its own power parameter is greater than the grid-connected power according to the grid parameter field, the voltage parameter, power parameter, and frequency parameter are filled into the corresponding array;

[0016] The wind turbine set with the largest voltage parameter and power parameter is selected as the master control set and connected to the grid, and the master control set grid connection state field in the grid connection data frame is set to the wind turbine set.

[0017] In a specific embodiment, the cooperative unit is used to determine that the grid-connected status field of the master control unit is not empty, and send the grid-connected data frame to the microgrid controller every preset period, so that the microgrid controller determines that the grid-connected status parameter returned by the cooperative unit is empty, and when the cooperative unit's own power parameter is greater than the grid-connected power of the power grid, the collector bus supplies power to the cooperative unit to connect the cooperative unit to the collector bus.

[0018] In a specific embodiment, the microgrid controller is also used to determine whether the grid-connected status parameter returned by the cooperative unit is not empty, and when the voltage parameter of the cooperative unit itself is less than a preset percentage of the grid voltage parameter, it is used to determine whether the voltage of other wind turbines connected to the collector bus is load balanced after compensating for the cooperative unit. If not, the isolation device is controlled to be cut off to allow the cooperative unit to exit the grid.

[0019] In a specific embodiment, the grid-connected data frame also includes a priority grid-connected field, which is used to record the cooperative unit that has exited the grid; the microgrid controller is also used to fill in the priority grid-connected field with the serial number of the cooperative unit that has exited the grid; when the microgrid controller determines that the cooperative unit meets the grid-connected conditions again, it prioritizes the collector bus to supply power to the cooperative unit to connect the cooperative unit to the collector bus, and deletes the serial number of the cooperative unit from the grid-connected data frame.

[0020] In a specific embodiment, the microgrid controller controls the output voltage and frequency of the cooperative unit according to the voltage fluctuation of the master unit, so that the voltage output to the collector bus has a fixed voltage and frequency.

[0021] Beneficial effects of the present invention:

[0022] A grid-connected collaborative processing method for wind turbines with energy storage inverters of the present invention generates a grid-connected data frame, wherein the grid-connected data frame includes a grid-connected status field of a master control unit, a grid parameter field, and a wind turbine operating parameter field; the grid-connected data frame is sent to each wind turbine, and when the wind turbine determines that the grid-connected status field of the master control unit is empty, when the wind turbine determines that its own power parameter is greater than the grid-connected power of the grid according to the grid parameter field, the voltage parameter, power parameter, and frequency parameter are filled into the corresponding array; the wind turbine with the largest voltage parameter and power parameter is selected as the master control unit and connected to the grid, and the grid-connected status field of the master control unit in the grid-connected data frame is set to the wind turbine. Thus, grid connection can be achieved even when the wind farm is powered off. In addition, by setting the master control unit and the collaborative unit, the success rate of grid connection can be improved, and the problem of being unable to connect to the grid again after grid connection failure due to insufficient power supply of the energy storage inverter device can be avoided.

[0023] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic flow chart of a method for grid-connected collaborative processing of wind turbines with energy storage inverters provided by an embodiment of the present invention;

[0025] Figure 2 The present invention provides a block diagram of a wind turbine grid-connected collaborative processing system module with energy storage and inverter according to an embodiment of the present invention. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.

[0027] Embodiment 1

[0028] See also Figure 1 , Figure 1 It is a flow chart of a method for coordinated processing of wind turbine grid connection with energy storage inverter provided in an embodiment of the present invention, which is applied to several wind turbines 10, wherein the wind turbines 10 are connected to a collector bus 30 via an isolation device 20, and the wind turbines 10 include a main control unit 11 and several cooperative units 12, wherein the main control unit 11 is connected to an energy storage inverter device 40 so that the main control unit 11 is powered by the energy storage inverter device 40 before being connected to the grid or the main control unit 11 is charged to the energy storage inverter device 40 after being connected to the grid.

[0029] It should be noted that the number of wind turbines 10 depends on the actual scenario and can be divided artificially for easy management. The voltage of the collector bus 30 can also be adjusted according to actual needs. If the number of connected wind turbines 10 is small, it can be adjusted to a smaller value. If the number of connected wind turbines 10 is large, it can be adjusted to a larger value, generally set to 20-50KV. The isolation device 20 can be, for example, an isolating switch or a circuit breaker. Each wind turbine is connected to the collector bus 30 through the isolation device 20, so that the isolation device 20 controls the connection or disconnection of the wind turbine 10.

[0030] The energy storage inverter device 40 of this embodiment can supply power to the wind turbine to provide the voltage required for grid connection. In the case where the power grid cannot provide the grid connection voltage for the wind turbine 10, the wind turbine 10 cannot be actively connected to the grid. In this embodiment, the energy storage inverter device 40 can provide the voltage required for grid connection. However, since the power supply of the energy storage inverter device 40 is limited, it is impossible to drive multiple wind turbines 10 to connect to the grid. Therefore, it is necessary to select the wind turbine 10 with the best grid connection conditions among all the wind turbines 10 to supply power to it.

[0031] The method includes:

[0032] S1. Generate a grid-connected data frame, wherein the grid-connected data frame includes a grid-connected status field of the master control unit 11, a grid parameter field, and an operating parameter field of the wind turbine unit 10; the operating parameter field of the wind turbine unit 10 includes a plurality of arrays, the number of which corresponds to the number of wind turbine units 10, and each array includes a grid-connected status parameter, a voltage parameter, a power parameter, and a frequency parameter, wherein the grid-connected status field of the master control unit 11 is used to characterize whether the master control unit 11 has been determined, and the grid-connected status parameter is used to characterize whether the cooperative unit 12 is connected to the collector bus 30. When the wind turbine unit 10 is grid-connected, the operating parameters of the wind turbine unit 10 are actual measured values, and when the wind turbine unit 10 is not grid-connected, the operating parameters of the wind turbine unit 10 are estimated values.

[0033] The microgrid controller 50 is connected to the main controller of each wind turbine set 10. When the wind turbine sets 10 are not connected to the grid, after the grid-connected data frame is sent to the main controller of each wind turbine set 10, each wind turbine set 10 predicts the voltage, power and frequency that can be achieved after grid connection according to the wind conditions, thereby generating a corresponding array and sending it to the microgrid controller 50 through the main controller. When the grid-connected status field of the master control unit 11 is empty, it indicates that no wind turbine set 10 has been connected to the grid yet. At this time, it is necessary to select a suitable wind turbine set 10 as the master control unit 11. If the grid-connected status field of the master control unit 11 is not empty, other wind turbine sets 10 participate in grid connection or grid withdrawal as cooperative units 12. When the wind turbine set 10 is not connected to the grid, it does not have actual operating data. Therefore, the estimated values ​​of voltage, power and frequency are calculated according to the current wind conditions such as wind speed and wind direction. Specifically, this embodiment makes an estimate through the wind speed-power curve. Since the rated power, voltage and frequency of different wind turbines 10 are different, the grid connection requirements of different regions and different power grids are also different, so whether it is suitable for grid connection needs to be judged according to the specific situation. Generally, the isolation device 20 is directly controlled by the wind turbine 10, and this embodiment can preferably be directly controlled by the microgrid controller 50, for example, by wireless communication.

[0034] S2. Send the grid-connected data frame to each wind turbine set 10. When the wind turbine set 10 determines that the grid-connected status field of the master control set 11 is empty, and determines that its own power parameter is greater than the grid-connected power according to the grid parameter field, fill the voltage parameter, power parameter, and frequency parameter into the corresponding array.

[0035] The power parameter at this time is the estimated value. Since the wind speed and wind direction at the location of each wind turbine 10 are different, their power parameters are also different. It is necessary to select wind turbines 10 that meet the grid connection conditions. When the grid connection status field of the master control unit 11 is empty, it indicates that the master control unit 11 has not been selected yet. Therefore, all wind turbines 10 report their own power parameters according to their own conditions. The grid parameter field includes the grid power parameter. For the master control unit 11, it is the first wind turbine 10 connected to the grid, so it must ensure that its power is large enough to complete the grid connection. For the subsequent wind turbines 10 connected to the grid, since the master control unit 11 is already connected, it only needs to ensure the balance of load and power generation, and no strict requirements are required. Therefore, the grid connection data frame can be filled and sent only when it is judged that its own power parameter is greater than the grid connection power of the grid, otherwise no operation is performed.

[0036] S3 , selecting the wind turbine set 10 with the largest voltage parameter and power parameter as the master control set 11 and connecting it to the grid, and setting the grid connection status field of the master control set 11 in the grid connection data frame to the wind turbine set 10 .

[0037] In order to improve the success rate of grid connection, if multiple wind turbines 10 meet the basic grid connection conditions, the one with the best conditions is selected as the master unit 11 for grid connection. Of course, there are also situations where all wind turbines 10 do not meet the grid connection conditions. Preferably, when only one wind turbine 10 sends a grid connection data frame, the wind turbine 10 is used as an alternative master unit 11, and the grid connection data frame continues to be sent to each wind turbine 10 until at least two wind turbines 10 send grid connection data frames. It is determined whether the alternative master unit 11 still meets the grid connection conditions. If so, the alternative master unit 11 is used as the master unit 11. If not, the wind turbine 10 with the largest voltage parameters and power parameters is selected from the at least two wind turbines 10 as the master unit 11 and connected to the grid.

[0038] In a specific embodiment, when it is determined that the grid-connected status field of the master control unit 11 is not empty, the cooperative unit 12 sends the grid-connected data frame to the microgrid controller 50 at preset intervals. When the microgrid controller 50 determines that the grid-connected status parameter returned by the cooperative unit 12 is empty, and the power parameter of the cooperative unit 12 itself is greater than the grid-connected power of the power grid, the collector bus 30 supplies power to the cooperative unit 12 to connect the cooperative unit 12 to the collector bus 30.

[0039] If the grid-connected status field of the master control unit 11 is not empty, it means that at least one wind turbine unit 10 has been connected to the grid. At this time, other wind turbine units 10 that have not yet been connected to the grid need to be connected to the grid one after another. When other wind turbine units 10 are connected to the grid, they no longer need to rely on the energy storage inverter device 40, but only need to be powered by the collector bus 30.

[0040] When the collector bus 30 supplies power to the wind turbine 10 that is not connected to the grid, it will cause grid fluctuations. Preferably, if there are fewer wind turbines 10 on the grid, the attenuation of the transmission voltage or power also needs to be considered. Since the start-up time of the wind turbine 10 is relatively slow, it needs to be powered continuously during the startup phase, which generally lasts for several hours to several days. Therefore, it is also necessary to ensure the stability of the grid voltage, otherwise it may cause startup failure or unstable grid voltage leading to other safety accidents. It should be noted that after the wind turbine 10 is connected to the grid, it is necessary to conduct a trial grid operation. This embodiment does not consider the trial grid phase, but only considers the grid connection of the wind turbine 10 during the startup phase. When the cooperative unit 12 is connected to the grid, it is necessary to predict the power data based on the capacity and startup time of the cooperative unit 12 to be connected to the grid. The prediction time depends on the situation, and the general period is 12-72 hours.

[0041] When the microgrid controller 50 determines that the grid connection state parameter returned by the cooperative unit 12 is empty and the power parameter of the cooperative unit 12 itself is greater than the grid connection power, it sends a grid connection request to each wind turbine unit 10 whose grid connection state parameter is not empty;

[0042] After receiving the grid connection request, the power data for the next 12-72 hours is predicted based on the wind speed-power curve, and the minimum power value is sent to the microgrid controller 50;

[0043] The microgrid controller 50 calculates the additional power based on the received several minimum power values ​​and the current grid transmission power. When the additional power is greater than the starting power of the cooperative unit 12 to be connected to the grid, the collector bus 30 supplies power to the cooperative unit 12 to connect the cooperative unit 12 to the collector bus 30; otherwise, the grid connection request is resent after one cycle ends.

[0044] In a specific embodiment, when the microgrid controller 50 determines that the grid-connected status parameter returned by the cooperative unit 12 is not empty and the voltage parameter of the cooperative unit 12 itself is less than the preset percentage of the grid voltage parameter, it determines whether the voltage of other wind turbines 10 connected to the collector bus 30 is load balanced after compensating for the cooperative unit 12. If not, the isolation device is controlled to be cut off to allow the cooperative unit 12 to exit the grid.

[0045] In order to improve the grid connection efficiency, in this embodiment, when the cooperative unit 12 no longer meets the grid connection conditions, compensation is performed through other wind turbine units 10, and the preferred preset percentage can be set to at least 70%.

[0046] In a specific embodiment, the grid-connected data frame also includes a priority grid-connected field, which is used to record the cooperative unit 12 that has exited the grid; the microgrid controller 50 fills the serial number of the cooperative unit 12 that has exited the grid in the priority grid-connected field; when the microgrid controller 50 determines that the cooperative unit 12 meets the grid-connected conditions again, it prioritizes the collector bus 30 to supply power to the cooperative unit 12 to connect the cooperative unit 12 to the collector bus 30, and deletes the serial number of the cooperative unit 12 from the grid-connected data frame.

[0047] Generally, the wind turbine 10 needs to be tested for various indicators before being connected to the grid. For example, installation and commissioning work needs to be performed to confirm that all electrical and mechanical equipment meet the requirements. In addition, it is necessary to ensure that the cables, switches and protection devices of the grid-connected wind turbine 10 have been installed and connected, and to check whether all management and control systems are correctly configured to communicate and control with the grid. For the cooperative unit 12 that is out of the grid, no secondary preparation is required. Therefore, by recording the priority grid connection field, the grid connection time can be saved and the grid connection efficiency can be improved.

[0048] The microgrid controller 50 controls the output voltage and frequency of the cooperative unit 12 according to the voltage fluctuation of the master unit 11, so that the voltage output to the collector bus 30 has a fixed voltage and frequency.

[0049] Since the traditional control method generally uses droop control for adjustment, there is no distinction between the main control unit 11 and the cooperative unit 12. The power, voltage, and frequency after grid connection are synchronized with the power grid in a unified manner and centrally managed. Therefore, all wind turbines 10 may be disconnected from the grid, and there is no unified reference. Adjustments are made only after the network changes, which makes it have a certain lag, and if the power grid or some wind turbines 10 fluctuate greatly, it may cause an imbalance in the power grid flow and cause systemic risks. In this embodiment, the voltage or frequency fluctuation of the main control unit 11 is used as the only reference. It only needs to monitor the main control unit 11, and the other cooperative units 12 only need to cooperate in output. Even if there are abnormalities in other cooperative units 12, it will not affect the main control unit 11, thereby improving the stability of the output.

[0050] See also Figure 2 The present invention also provides a grid-connected collaborative processing system for wind turbines 10 with energy storage inverter, comprising a plurality of wind turbines 10, wherein the wind turbines 10 are connected to a collector bus 30 through an isolation device, wherein the wind turbines 10 include a main control unit 11 and a plurality of cooperative units 12, wherein the main control unit 11 is connected to an energy storage inverter device 40 so that the main control unit 11 is powered by the energy storage inverter device 40 before being connected to the grid or the main control unit 11 is charged to the energy storage inverter device 40 after being connected to the grid; the wind turbines 10 are all connected to a microgrid controller 50;

[0051] The microgrid controller 50 is used to generate a grid-connected data frame, which includes a grid-connected status field of the master control unit 11, a grid parameter field, and an operating parameter field of the wind turbine unit 10; the operating parameter field of the wind turbine unit 10 includes a plurality of arrays, the number of which corresponds to the number of wind turbine units 10, and each array includes a grid-connected status parameter, a voltage parameter, a power parameter, and a frequency parameter, wherein the grid-connected status field of the master control unit 11 is used to indicate whether the master control unit 11 has been determined, and the grid-connected status parameter is used to indicate whether the cooperative unit 12 is connected to the collector bus 30. When the wind turbine unit 10 is grid-connected, the operating parameters of the wind turbine unit 10 are actual measured values, and when the wind turbine unit 10 is not grid-connected, the operating parameters of the wind turbine unit 10 are estimated values;

[0052] The grid-connected data frame is sent to each wind turbine 10. When the wind turbine 10 determines that the grid-connected state field of the master control unit 11 is empty, and determines that its own power parameter is greater than the grid-connected power according to the grid parameter field, the voltage parameter, power parameter, and frequency parameter are filled into the corresponding array;

[0053] The wind turbine set 10 with the largest voltage parameter and power parameter is selected as the master control set 11 and connected to the grid, and the grid connection state field of the master control set 11 in the grid connection data frame is set to the wind turbine set 10 .

[0054] In a specific embodiment, the cooperative unit 12 is used to determine that the grid-connected status field of the main control unit 11 is not empty, and sends the grid-connected data frame to the microgrid controller 50 every preset period, so that the microgrid controller 50 determines that the grid-connected status parameter returned by the cooperative unit 12 is empty, and when the power parameter of the cooperative unit 12 itself is greater than the grid-connected power of the power grid, the collector bus 30 supplies power to the cooperative unit 12 to connect the cooperative unit 12 to the collector bus 30.

[0055] In a specific embodiment, the microgrid controller 50 is also used to determine whether the grid-connected status parameter returned by the cooperative unit 12 is not empty, and when the voltage parameter of the cooperative unit 12 itself is less than the preset percentage of the grid voltage parameter, it is used to determine whether the voltage of other wind turbines 10 connected to the collector bus 30 is load balanced after compensating for the cooperative unit 12. If not, the isolation device is controlled to be cut off to allow the cooperative unit 12 to exit the grid.

[0056] In a specific embodiment, the grid-connected data frame also includes a priority grid-connected field, which is used to record the cooperative unit 12 that has exited the grid; the microgrid controller 50 is also used to fill in the serial number of the cooperative unit 12 that has exited the grid in the priority grid-connected field; when the microgrid controller 50 determines that the cooperative unit 12 meets the grid-connected conditions again, it prioritizes the collector bus 30 to supply power to the cooperative unit 12 to connect the cooperative unit 12 to the collector bus 30, and deletes the serial number of the cooperative unit 12 from the grid-connected data frame.

[0057] In a specific embodiment, the microgrid controller 50 controls the output voltage and frequency of the cooperative unit 12 according to the voltage fluctuation of the master unit 11, so that the voltage output to the collector bus 30 has a fixed voltage and frequency.

[0058] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification.

[0059] Although the present application is described herein in conjunction with various embodiments, in the process of implementing the claimed application, those skilled in the art may understand and implement other variations of the disclosed embodiments by viewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "one" or "an" does not exclude multiple situations. A single processor or other unit may implement several functions listed in a claim. Certain measures are recorded in different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0060] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A method for grid-connected coordinated processing of wind turbines with energy storage and inverter, characterized in that: Applied to several wind turbines, the wind turbines are connected to the collector busbar through an isolation device, the wind turbines include a main control unit and several cooperative units, the main control unit is connected to an energy storage inverter device so that the main control unit is powered by the energy storage inverter device before being connected to the grid or the main control unit charges the energy storage inverter device after being connected to the grid; The method includes: Generate a grid-connected data frame, the grid-connected data frame includes a master control unit grid-connected status field, a power grid parameter field, and a wind turbine unit operating parameter field; the wind turbine unit operating parameter field includes a plurality of array groups, the number of the plurality of array groups corresponds to the number of wind turbine units, and each array group includes a grid-connected status parameter, a voltage parameter, a power parameter, and a frequency parameter, wherein the master control unit grid-connected status field is used to characterize whether the master control unit has been determined, and the grid-connected status parameter is used to characterize whether the cooperative unit is connected to the collector bus, when the wind turbine unit is grid-connected, the wind turbine unit operating parameter is an actual measured value, and when the wind turbine unit is not grid-connected, the wind turbine unit operating parameter is an estimated value; The grid-connected data frame is sent to each wind turbine group. When the wind turbine group determines that the grid-connected state field of the master control group is empty, and determines that its own power parameter is greater than the grid-connected power according to the grid parameter field, the voltage parameter, power parameter, and frequency parameter are filled into the corresponding array; The wind turbine set with the largest voltage parameter and power parameter is selected as the master control set and connected to the grid, and the master control set grid connection state field in the grid connection data frame is set to the wind turbine set.

2. The method for grid-connected coordinated processing of wind turbines with energy storage inverter according to claim 1, characterized in that: When it is determined that the grid-connected status field of the master control unit is not empty, the cooperative unit sends the grid-connected data frame to the microgrid controller every preset period. When the microgrid controller determines that the grid-connected status parameter returned by the cooperative unit is empty and the power parameter of the cooperative unit itself is greater than the grid-connected power of the power grid, the collector bus supplies power to the cooperative unit to connect the cooperative unit to the collector bus.

3. The method for grid-connected coordinated processing of wind turbines with energy storage inverter according to claim 2, characterized in that: When it is determined that the grid-connected status parameter returned by the cooperative unit is not empty and the voltage parameter of the cooperative unit itself is less than the preset percentage of the grid voltage parameter, it is determined whether the voltage of other wind turbines connected to the collector bus is load balanced after compensating the cooperative unit. If not, the isolation device is controlled to be cut off to allow the cooperative unit to exit the grid.

4. The method for grid-connected coordinated processing of wind turbines with energy storage inverter according to claim 3 is characterized in that: The grid-connected data frame also includes a priority grid-connected field, which is used to record the cooperative unit that has exited the grid; the microgrid controller fills the serial number of the cooperative unit that has exited the grid in the priority grid-connected field; when the microgrid controller determines that the cooperative unit meets the grid-connected conditions again, it prioritizes the collector bus to supply power to the cooperative unit to connect the cooperative unit to the collector bus, and deletes the serial number of the cooperative unit from the grid-connected data frame.

5. The method for grid-connected coordinated processing of wind turbines with energy storage inverter according to claim 1, characterized in that: The output voltage and frequency of the cooperative unit are controlled according to the voltage fluctuation of the main control unit so that the voltage output to the collector bus has a fixed voltage and frequency.

6. A wind turbine grid-connected collaborative processing system with energy storage and inverter, characterized in that: It comprises a plurality of wind turbine sets, which are connected to a collector busbar through an isolation device, and the wind turbine sets comprise a main control set and a plurality of cooperative sets, and the main control set is connected to an energy storage inverter device so that the main control set is powered by the energy storage inverter device before being connected to the grid, or the main control set charges the energy storage inverter device after being connected to the grid; the wind turbine sets are all connected to a microgrid controller; The microgrid controller is used to generate a grid-connected data frame, which includes a master control unit grid-connected status field, a power grid parameter field, and a wind turbine unit operating parameter field; the wind turbine unit operating parameter field includes a plurality of array groups, the number of which corresponds to the number of wind turbine units, and each array group includes a grid-connected status parameter, a voltage parameter, a power parameter, and a frequency parameter, wherein the master control unit grid-connected status field is used to characterize whether the master control unit has been determined, and the grid-connected status parameter is used to characterize whether the cooperative unit is connected to the collector bus, when the wind turbine unit is grid-connected, the wind turbine unit operating parameter is an actual measured value, and when the wind turbine unit is not grid-connected, the wind turbine unit operating parameter is an estimated value; The grid-connected data frame is sent to each wind turbine group. When the wind turbine group determines that the grid-connected state field of the master control group is empty, and determines that its own power parameter is greater than the grid-connected power according to the grid parameter field, the voltage parameter, power parameter, and frequency parameter are filled into the corresponding array; The wind turbine set with the largest voltage parameter and power parameter is selected as the master control set and connected to the grid, and the master control set grid connection state field in the grid connection data frame is set to the wind turbine set.

7. The wind turbine grid-connected collaborative processing system with energy storage inverter according to claim 6 is characterized in that: The cooperative unit is used to determine that when the grid-connected status field of the main control unit is not empty, the grid-connected data frame is sent to the microgrid controller every preset period, so that the microgrid controller determines that the grid-connected status parameter returned by the cooperative unit is empty, and when the cooperative unit's own power parameter is greater than the grid-connected power of the power grid, the collector bus supplies power to the cooperative unit to connect the cooperative unit to the collector bus.

8. The wind turbine grid-connected collaborative processing system with energy storage inverter according to claim 6 is characterized in that: The microgrid controller is also used to determine whether the grid-connected status parameters returned by the cooperative unit are not empty, and when the voltage parameters of the cooperative unit itself are less than the preset percentage of the grid voltage parameters, it is used to determine whether the voltage of other wind turbines connected to the collector bus is load balanced after compensating for the cooperative unit. If not, the isolation device is controlled to be cut off to allow the cooperative unit to exit the grid.

9. The wind turbine grid-connected collaborative processing system with energy storage inverter according to claim 8 is characterized in that: The grid-connected data frame also includes a priority grid-connected field, which is used to record the cooperative unit that has exited the grid; the microgrid controller is also used to fill in the priority grid-connected field with the serial number of the cooperative unit that has exited the grid; when the microgrid controller determines that the cooperative unit meets the grid-connected conditions again, it prioritizes the collector bus to supply power to the cooperative unit to connect the cooperative unit to the collector bus, and deletes the serial number of the cooperative unit from the grid-connected data frame.

10. The wind turbine grid-connected collaborative processing system with energy storage inverter according to claim 6, characterized in that: The microgrid controller controls the output voltage and frequency of the cooperative unit according to the voltage fluctuation of the master unit, so that the voltage output to the collector bus has a fixed voltage and frequency.

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