Coupling control method based on one-machine-one-storage new energy station

Abstract

The present invention relates to the field of coupling and control technology of new energy stations, and solves the technical problem that the traditional one-machine-one-storage coupling control cannot be applied to the current power grid optimization dispatching needs, and in particular to a coupling control method based on a one-machine-one-storage new energy station, the method comprising: configuring a storage body of corresponding required capacity for each new energy unit according to the power grid demand in the local area, and configuring a DC or AC coupling mode between the new energy unit and the power grid side according to the power grid demand. The present invention can select a coupling control mode suitable for different new energy units and power grids according to the DC or AC coupling, and there is no need to change the primary structure of the new energy unit, and the energy storage body is not restricted by the power type and energy type, thereby reducing the operating cost of the new energy unit and the maintenance cost of the power grid, improving the absorption capacity of renewable energy such as photovoltaic and wind power, and promoting the sustainable development of new energy.

Description

Technical Field

[0001] The present invention relates to the field of coupling and control technology of new energy stations, and in particular to a coupling control method based on a one-machine-one-storage new energy station. Background Art

[0002] One-machine-one-storage coupling technology is an innovative energy storage mode, which is mainly used in the field of new energy, especially renewable energy systems such as wind power. By organically combining photovoltaic or wind turbines with energy storage devices, an independent energy storage power generation unit is formed. This technology realizes energy complementarity and optimized scheduling between wind turbines and energy storage devices through wind-storage collaborative control technology, thereby improving the stability of wind turbines and the reliability of the power grid.

[0003] Since each new energy unit needs to be equipped with a certain capacity of energy storage according to the needs of the local power grid. The configured energy storage may be power-type energy storage or energy-type energy storage, which leads to the variability of the coupling mode between the new energy unit and the power grid. Therefore, it is necessary to modify the hardware of the new energy unit to meet the stability requirements of the coupling, and jointly dispatch the new energy unit and one machine and one storage to meet the AGC, AVC, primary frequency regulation, inertia control and rapid voltage regulation of the power grid. If the corresponding coupling mode and control cannot be selected according to the actual situation, the energy conversion efficiency will be reduced, and even damage to the system. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a coupling control method based on a one-machine-one-storage new energy station, which solves the technical problem that the traditional one-machine-one-storage coupling control cannot be applied to the current power grid optimization scheduling needs.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: a coupling control method based on a one-machine-one-storage new energy station, the method comprising:

[0006] According to the local area's grid demand, each new energy unit is equipped with a storage unit of the corresponding required capacity, where the grid demand includes the coupling between the new energy unit and the storage unit on the DC side, and the coupling between the new energy unit and the storage unit on the AC side;

[0007] Configure the DC or AC coupling mode between the new energy unit and the grid side according to the grid demand. The coupling modes include one-machine-one-storage coupling of photovoltaic modules and one-machine-one-storage coupling of wind turbine modules.

[0008] In the one-machine-one-storage coupling of the photovoltaic module in the DC coupling mode, the control mode is: if the energy storage body is a power-type energy storage, the small disturbance of the DC bus is controlled by the energy storage body, and the large disturbance is controlled by the photovoltaic array; if it is an energy-type energy storage, the small disturbance of the DC bus is controlled by the photovoltaic array, and the large disturbance is controlled by the energy storage body;

[0009] In the DC coupling mode, in the one-machine-one-storage coupling of the wind turbine module, the control method is: when the active power requires slow adjustment, it is achieved by the wind turbine pitch control; when the active power requires fast adjustment, it is achieved by the energy storage combined with the wind turbine pitch control, that is, the energy storage body is adjusted quickly, and then the wind turbine pitch control is supplemented;

[0010] In the AC coupling mode, the coupling control includes a new energy stand-alone machine as the main control mode, a storage coordination controller as the main control mode and a mutual independent control mode, wherein the new energy stand-alone machine includes a new energy stand-alone machine main control system as the control host, and the energy storage body includes an energy storage coordination controller as the control host.

[0011] Furthermore, the new energy unit includes a photovoltaic module and a wind turbine power generation module in renewable energy, and the energy storage body includes power-type energy storage and energy-type energy storage.

[0012] Furthermore, the one-machine-one-storage coupling of the photovoltaic module in the DC coupling mode includes: a grid side that is allowed to be incorporated into the local regional grid, and a photovoltaic array in the photovoltaic module and an energy storage body provided corresponding to the photovoltaic array, wherein the photovoltaic array is connected to the DC bus through a first DC / DC module, and the energy storage body is connected to the DC bus through a second DC / DC module;

[0013] The grid side and the DC bus are connected via a grid-side converter, the grid-side converter executes external instructions, and the first DC / DC and the second DC / DC cooperate with each other to maintain the stability of the DC bus.

[0014] Furthermore, the one-machine-one-storage coupling of the wind turbine module in the DC coupling mode includes: a grid side that is allowed to be incorporated into the local regional grid, and a wind turbine module and a corresponding energy storage body, wherein the energy storage body is connected to the DC bus through a second DC / DC module, and the wind turbine module is connected to the DC bus through a machine-side converter;

[0015] The grid side and the DC bus are connected via a grid-side converter, which executes external instructions.

[0016] Furthermore, in the one-machine-one-storage coupling of the wind turbine module in the DC coupling mode, the energy storage body is configured as a power-type energy storage, and the SOC is maintained at 50% when the energy storage body operates normally.

[0017] Furthermore, the AC coupling method includes: allowing the grid side to be incorporated into the local regional power grid, a box transformer connected to the grid side, a new energy unit directly connected to the low-voltage side of the box transformer, adding an energy storage interval on the low-voltage side of the box transformer, and the energy storage body is connected to the low-voltage side of the box transformer through a transformer after passing through an AC / DC converter.

[0018] Furthermore, the new energy stand-alone main control mode includes a new energy stand-alone main control system that establishes a communication network connection with the new energy stand-alone machine, and the new energy stand-alone machine establishes a communication connection control with the converter AC / DC and the energy storage body through the energy storage coordination controller. The new energy stand-alone main control system is used to control the new energy stand-alone machine and control the energy storage coordination controller to respond to external control instructions, thereby realizing the overall inertia of one machine and one storage, primary frequency modulation, AGC and AVC.

[0019] Furthermore, the energy storage coordination controller is a main control mode including an energy storage coordination controller that establishes a communication network connection with a single new energy machine, the energy storage coordination controller establishes a communication connection control with the converter AC / DC and the energy storage body, and the energy storage coordination controller is used to control the active and reactive power of the single new energy machine to respond to external control instructions, and realize the overall inertia, primary frequency modulation, AGC and AVC of one machine and one storage.

[0020] Furthermore, the mutually independent control mode includes an energy storage coordination controller that establishes a communication connection control with the converter AC / DC and the energy storage body. The new energy unit and the energy storage coordination controller are independent of each other and each accepts external control instructions separately to realize the overall inertia, primary frequency regulation, AGC and AVC of one machine and one storage at the station level.

[0021] By means of the above technical solution, the present invention provides a coupling control method based on a one-machine-one-storage new energy station, which has at least the following beneficial effects:

[0022] 1. The present invention can select a coupling control mode suitable for different new energy units and power grids according to the coupling of DC or AC, and there is no need to change the primary structure of the new energy unit. The energy storage body is not restricted by the power type and energy type, thereby reducing the operating cost of the new energy unit and the maintenance cost of the power grid, improving the absorption capacity of renewable energy such as photovoltaic and wind power, and promoting the sustainable development of new energy.

[0023] 2. The present invention can realize the coordinated operation between photovoltaic and wind power modules and energy storage devices. When the resources of new energy units are sufficient, the energy storage device can absorb excess electricity. When the resources are insufficient or the power grid needs it, the energy storage device can release electricity to maintain the stable operation of the energy units and the supply and demand balance of the power grid.

[0024] 3. The coupling control method proposed in the present invention enables the capacity and type of the energy storage device to be flexibly configured according to the rated power and actual needs of the new energy unit. At the same time, it improves the energy utilization efficiency of the energy storage device and the power generation efficiency of the new energy unit, reduces the impact of the fluctuation of the new energy unit on the power grid, and improves the stability and reliability of the power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0026] Figure 1 This is a schematic diagram of the coupling of a photovoltaic module, a machine and a storage device on the DC side of the present invention;

[0027] Figure 2 This is a schematic diagram of the one-machine-one-storage coupling of the DC-side fan module of the present invention;

[0028] Figure 3 This is a schematic diagram of the coupling of a single machine and a storage unit of new energy on the AC side of the present invention;

[0029] Figure 4 This is a principle block diagram of the new energy stand-alone main control mode of the present invention;

[0030] Figure 5 This is a principle block diagram of the energy storage coordination controller of the present invention in the main control mode;

[0031] Figure 6 It is a principle block diagram of the mutually independent control mode of the present invention. DETAILED DESCRIPTION

[0032] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific implementation methods, so that the implementation process of how the present application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0033] Please refer to Figure 1-Figure 6 This embodiment proposes a coupling control method based on a one-machine-one-storage new energy station, which can realize the coupling mode of a new energy stand-alone machine according to the power storage or energy storage configured according to the needs of the local power grid, including DC coupling mode and AC coupling mode, and provides a control method for the corresponding coupling mode, so as to jointly dispatch a new energy stand-alone machine and one-machine-one-storage to meet the realization of the AGC, AVC, primary frequency regulation, inertia control and rapid voltage regulation functions of the power grid. The specific implementation method of the method is as follows:

[0034] A storage body with a corresponding required capacity is configured for each new energy unit according to the grid demand in the local area, where the grid demand includes the coupling between the new energy unit and the storage body on the DC side, and the coupling between the new energy unit and the storage body on the AC side; the new energy unit includes photovoltaic modules and wind turbine power generation modules in renewable energy; the storage body includes power-type energy storage and energy-type energy storage; the DC or AC coupling mode between the new energy unit and the grid side is configured according to the grid demand, and the coupling modes include one-machine-one-storage coupling of photovoltaic modules and one-machine-one-storage coupling of wind turbine modules.

[0035] like Figure 1 As shown, the one-machine-one-storage coupling of the photovoltaic module in the DC coupling mode includes: a grid side that is allowed to be incorporated into the local regional power grid, and a photovoltaic array in the photovoltaic module and an energy storage body corresponding to the photovoltaic array, wherein the photovoltaic array is connected to the DC bus through a first DC / DC module, and the energy storage body is connected to the DC bus through a second DC / DC module; the grid side and the DC bus are connected through a grid-side converter, the grid-side converter executes external instructions, and the first DC / DC and the second DC / DC cooperate with each other to maintain the stability of the DC bus.

[0036] The photovoltaic array is connected to the DC bus through the first DC / DC module, and the energy storage body is connected to the DC bus through the second DC / DC module. Among them, the grid-side converter executes external instructions, and the photovoltaic DC / DC and the DC / DC of the energy storage body cooperate with each other to maintain the stability of the DC bus. If it is power-type energy storage, the impact of the number of charge and discharge times on the energy storage body can be ignored, then the small disturbances of the DC bus are controlled by the energy storage, and the large disturbances are controlled by the photovoltaic array; if it is energy-type energy storage, considering the impact of frequent charging and discharging on the life of the energy storage body, the small disturbances of the DC bus are controlled by the photovoltaic array, and the large disturbances are controlled by the energy storage body.

[0037] like Figure 2 As shown, the one-machine-one-storage coupling of the wind turbine module in the DC coupling mode includes: the grid side that is allowed to be incorporated into the local regional power grid, and the wind turbine module and the corresponding energy storage body, wherein the energy storage body is connected to the DC bus through the second DC / DC module, and the wind turbine module is connected to the DC bus through the machine-side converter; the energy storage body is configured as power type energy storage, and the SOC of the energy storage body is maintained at 50% when it operates normally. The grid side and the DC bus are connected through the grid-side converter, and the grid-side converter executes external instructions.

[0038] This embodiment can realize the coordinated operation between photovoltaic and wind power modules and energy storage devices. When the resources of new energy units are sufficient, the energy storage device can absorb excess electricity, and when they are insufficient or required by the power grid, the energy storage device can release electricity to maintain the stable operation of the energy units and the supply and demand balance of the power grid.

[0039] The wind turbine side converter and the energy storage body are connected to the DC bus through the second DC / DC module. It is connected to the grid through the grid-side converter. The second DC / DC module, the machine-side converter and the grid-side converter are uniformly coordinated and controlled. Considering factors such as installation space and safety, it is recommended to configure power-type energy storage when the energy storage is coupled with the wind turbine on the DC side. The SOC should be kept at around 50% during normal operation of the energy storage. When active power requires slow adjustment, it is achieved by the wind turbine pitch change; when active power requires fast adjustment, it is achieved by the energy storage body combined with the wind turbine pitch change, that is, the energy storage body is quickly adjusted, and then the wind turbine pitch change is supplemented.

[0040] like Figure 3 As shown, the AC coupling method includes: allowing the grid side to be incorporated into the local regional power grid, the box transformer connected to the grid side, the new energy unit is directly connected to the low-voltage side of the box transformer, and the energy storage interval is added on the low-voltage side of the box transformer. The energy storage body is connected to the low-voltage side of the box transformer through a transformer after passing through the converter AC / DC. The new energy unit does not make any hardware changes, and the energy storage interval is added on the low-voltage side of the box transformer. The energy storage is connected to the low-voltage side of the box transformer through a transformer after passing through the converter. This coupling method does not require changing the primary structure of the new energy unit, the energy storage body is not restricted by the power type and energy type, and it is also convenient to expand the capacity.

[0041] In the AC coupling mode, the coupling control includes a new energy stand-alone machine as the main control mode, a storage coordination controller as the main control mode and a mutual independent control mode, wherein the new energy stand-alone machine includes a new energy stand-alone machine main control system as the control host, and the energy storage body includes an energy storage coordination controller as the control host.

[0042] This embodiment can select a coupling control mode suitable for different new energy units and the power grid according to the coupling of DC or AC, and there is no need to change the primary structure of the new energy unit. The energy storage body is not restricted by the power type and energy type, thereby reducing the operating cost of the new energy unit and the maintenance cost of the power grid, improving the absorption capacity of renewable energy such as photovoltaic and wind power, and promoting the sustainable development of new energy.

[0043] like Figure 4 As shown, red is the communication network. The new energy stand-alone control system is the host. In addition to controlling the new energy stand-alone, it also needs to control the energy storage coordination controller to respond to external control commands to achieve the overall inertia of one machine and one storage, primary frequency modulation, AGC and AVC and other functions. The new energy stand-alone is the main control mode, which includes a new energy stand-alone main control system that establishes a communication network connection with the new energy stand-alone. The new energy stand-alone establishes a communication connection control with the converter AC / DC and the energy storage body through the energy storage coordination controller. The new energy stand-alone main control system is used to control the new energy stand-alone and control the energy storage coordination controller to respond to external control commands to achieve the overall inertia of one machine and one storage, primary frequency modulation, AGC and AVC.

[0044] like Figure 5 As shown, red is the communication network. The energy storage coordination controller is the host. In addition to controlling the energy storage inverter, it also needs to control the active and reactive power of the new energy to respond to external control commands, and realize the overall inertia, primary frequency modulation, AGC and AVC functions of one machine and one storage. The energy storage coordination controller is an energy storage coordination controller that establishes a communication network connection with a single new energy machine in the main control mode. The energy storage coordination controller establishes a communication connection control with the converter AC / DC and the energy storage body. The energy storage coordination controller is used to control the active and reactive power of the new energy machine to respond to external control commands, and realize the overall inertia, primary frequency modulation, AGC and AVC of one machine and one storage.

[0045] like Figure 6 As shown, the red part is the communication network. The new energy stand-alone machine and energy storage are independent of each other, and both accept external control instructions separately to realize the inertia, primary frequency regulation, AGC and AVC functions of the one-machine-one-storage at the station level. The independent control mode includes an energy storage coordination controller that establishes a communication connection control with the converter AC / DC and the energy storage body. The new energy stand-alone machine and energy storage coordination controller are independent of each other, and both accept external control instructions separately to realize the inertia, primary frequency regulation, AGC and AVC of the one-machine-one-storage at the station level.

[0046] The coupling control method proposed in this embodiment enables the capacity and type of the energy storage device to be flexibly configured according to the rated power and actual needs of the new energy unit. At the same time, it improves the energy utilization efficiency of the energy storage device and the power generation efficiency of the new energy unit, reduces the impact of the fluctuation of the new energy unit on the power grid, and improves the stability and reliability of the power grid.

[0047] Those skilled in the art can understand that all or part of the steps in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a program, so the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0048] Each embodiment in this specification is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the above embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiments.

[0049] The above implementation methods have been described in detail. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A coupling control method based on a one-machine-one-storage new energy station, characterized in that: The method includes: According to the local area's grid demand, each new energy unit is equipped with a storage unit of the corresponding required capacity, where the grid demand includes the coupling between the new energy unit and the storage unit on the DC side, and the coupling between the new energy unit and the storage unit on the AC side; Configure the DC or AC coupling mode between the new energy unit and the grid side according to the grid demand. The coupling modes include one-machine-one-storage coupling of photovoltaic modules and one-machine-one-storage coupling of wind turbine modules. In the one-machine-one-storage coupling of the photovoltaic module in the DC coupling mode, the control mode is: if the energy storage body is a power-type energy storage, the small disturbance of the DC bus is controlled by the energy storage body, and the large disturbance is controlled by the photovoltaic array; if it is an energy-type energy storage, the small disturbance of the DC bus is controlled by the photovoltaic array, and the large disturbance is controlled by the energy storage body; In the DC coupling mode, in the one-machine-one-storage coupling of the wind turbine module, the control method is: when the active power requires slow adjustment, it is achieved by the wind turbine pitch control; when the active power requires fast adjustment, it is achieved by the energy storage combined with the wind turbine pitch control, that is, the energy storage body is adjusted quickly, and then the wind turbine pitch control is supplemented; In the AC coupling mode, the coupling control includes a new energy stand-alone machine as the main control mode, a storage coordination controller as the main control mode and a mutual independent control mode, wherein the new energy stand-alone machine includes a new energy stand-alone machine main control system as the control host, and the energy storage body includes an energy storage coordination controller as the control host.

2. The coupling control method according to claim 1, characterized in that: The new energy unit includes a photovoltaic module and a wind turbine power generation module in renewable energy, and the energy storage body includes power-type energy storage and energy-type energy storage.

3. The coupling control method according to claim 1, characterized in that: The one-machine-one-storage coupling of the photovoltaic module in the DC coupling mode includes: a grid side that is allowed to be incorporated into the local regional grid, and a photovoltaic array in the photovoltaic module and an energy storage body provided corresponding to the photovoltaic array, wherein the photovoltaic array is connected to the DC bus through a first DC / DC module, and the energy storage body is connected to the DC bus through a second DC / DC module; The grid side and the DC bus are connected via a grid-side converter, the grid-side converter executes external instructions, and the first DC / DC module and the second DC / DC module cooperate with each other to maintain the stability of the DC bus.

4. The coupling control method according to claim 1, characterized in that: The one-machine-one-storage coupling of the wind turbine module in the DC coupling mode includes: a grid side that is allowed to be incorporated into the local regional grid, and a wind turbine module and a corresponding energy storage body, wherein the energy storage body is connected to the DC bus through a second DC / DC module, and the wind turbine module is connected to the DC bus through a machine-side converter; The grid side and the DC bus are connected via a grid-side converter, which executes external instructions.

5. The coupling control method according to claim 1 or 4, characterized in that: In the one-machine-one-storage coupling of the wind turbine module in the DC coupling mode, the energy storage body is configured as power-type energy storage, and the SOC is maintained at 50% when the energy storage body operates normally.

6. The coupling control method according to claim 1, characterized in that: The AC coupling method includes: allowing the grid side to be incorporated into the local regional power grid, a box transformer connected to the grid side, a new energy unit directly connected to the low-voltage side of the box transformer, adding an energy storage interval on the low-voltage side of the box transformer, and the energy storage body is connected to the low-voltage side of the box transformer through a transformer after passing through an AC / DC converter.

7. The coupling control method according to claim 6, characterized in that: The new energy stand-alone main control mode includes a new energy stand-alone main control system that establishes a communication network connection with the new energy stand-alone. The new energy stand-alone establishes a communication connection control with the converter AC / DC and the energy storage body through the energy storage coordination controller. The new energy stand-alone main control system is used to control the new energy stand-alone and control the energy storage coordination controller to respond to external control instructions, thereby realizing the overall inertia of one machine and one storage, primary frequency modulation, AGC and AVC.

8. The coupling control method according to claim 6, characterized in that: The energy storage coordination controller is a main control mode, including an energy storage coordination controller that establishes a communication network connection with a single new energy machine. The energy storage coordination controller establishes a communication connection control with the converter AC / DC and the energy storage body. The energy storage coordination controller is used to control the active and reactive power of the single new energy machine to respond to external control instructions, and realize the overall inertia, primary frequency modulation, AGC and AVC of one machine and one storage.

9. The coupling control method according to claim 6, characterized in that: The independent control mode includes an energy storage coordination controller that establishes a communication connection control with the converter AC / DC and the energy storage body. The new energy unit and the energy storage coordination controller are independent of each other and both accept external control instructions separately to realize the overall inertia, primary frequency regulation, AGC and AVC of one machine and one storage at the station level.

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