A method and device for primary frequency modulation control of a wind farm

Abstract

A method and apparatus for primary frequency regulation control of a wind farm are provided. The method includes: acquiring the active power demand deficit, the wind power adjustable reserve power, and the charge state of the energy storage system of the wind farm; determining a response control mode based on the active power demand deficit, the wind power adjustable reserve power, and the charge state of the energy storage system; when the determined response control mode is a wind power response control mode, continuously controlling the wind turbine generators of the wind farm to adjust their active power within a first control cycle based on the active power demand deficit and the wind power adjustable reserve power; when the determined response control mode is an energy storage response control mode, continuously controlling the energy storage system of the wind farm to charge or discharge within a second control cycle based on the active power demand deficit; the first control cycle is longer than the second control cycle.

Description

Technical Field

[0001] This disclosure generally relates to the field of power technology, and more specifically, to a method and apparatus for primary frequency regulation control of a wind farm. Background Technology

[0002] The installed capacity of wind power connected to the grid has grown rapidly, and this scale will continue to increase in the future. In recent years, with the development of ultra-high voltage power grids and the large-scale and continuous grid connection of new energy sources, ultra-high voltage AC / DC hybrid power grids have gradually taken shape, resulting in significant changes in the grid structure and power supply structure, as well as profound changes in grid characteristics. Against the backdrop of high-penetration new energy access and large-capacity DC transmission feed-in, the operating conditions of large-scale wind power grid connection have become more complex.

[0003] With the increasing proportion of renewable energy, the frequency regulation capabilities of existing thermal and hydropower are insufficient, necessitating the participation of renewable energy in frequency control. Currently, there is a strong emphasis on "strengthening the flexible regulation role of the power supply side," focusing on stimulating the regulation initiative and potential of existing power sources through integrated models, optimizing the allocation of incremental regulatory power sources or energy storage, and thereby achieving mutual support and complementarity among various power sources without increasing the peak-shaving pressure on the power system. Therefore, a large number of commercial energy storage projects have been applied in ancillary services both domestically and internationally. This makes the demand for energy storage frequency regulation and control strategies a current research hotspot. Summary of the Invention

[0004] An exemplary embodiment of this disclosure provides a primary frequency regulation control method and apparatus for a wind farm, which can effectively and reasonably coordinate and control the wind turbine generators and energy storage systems of the wind farm to participate in the primary frequency regulation of the power grid.

[0005] According to a first aspect of the present disclosure, a primary frequency regulation control method for a wind farm is provided, comprising: acquiring the active power demand deficit of the primary frequency regulation of the wind farm, the adjustable reserve power of the wind power in the wind farm, and the charge state of the energy storage system; determining a response control mode based on the active power demand deficit, the adjustable reserve power of the wind power, and the charge state of the energy storage system; when the determined response control mode is a wind power response control mode, continuously controlling the wind turbine generators of the wind farm to adjust the active power within a first control cycle based on the active power demand deficit and the adjustable reserve power of the wind power; when the determined response control mode is an energy storage response control mode, continuously controlling the energy storage system of the wind farm to charge or discharge within a second control cycle based on the active power demand deficit; wherein the first control cycle is longer than the second control cycle.

[0006] Optionally, when the active power demand deficit is less than 0, the steps for determining the response control mode based on the active power demand deficit, the adjustable reserve power of wind power, and the charge state of the energy storage system include: when the energy storage system is in a charging lockout state, or when the charge state of the energy storage system is higher than or equal to the upper limit value, the response control mode is determined to be the wind power response control mode; when the charge state of the energy storage system is higher than the upper boundary value but lower than the upper limit value, and the reduction of reserve power by wind power can meet the active power demand deficit, the response control mode is determined to be the energy storage response control mode; or, when the charge state of the energy storage system is lower than or equal to the upper boundary value, the response control mode is determined to be the energy storage response control mode, wherein the upper limit value is the charge state value when the energy storage system is fully charged, and the upper boundary value is lower than the upper limit value.

[0007] Optionally, when the active power demand deficit is greater than 0, the steps for determining the response control mode based on the active power demand deficit, the adjustable reserve power of wind power, and the charge state of the energy storage system include: when the energy storage system is in a discharge-locked state, or when the charge state of the energy storage system is lower than or equal to the lower limit value, the response control mode is determined to be the wind power response control mode; when the charge state of the energy storage system is higher than the lower limit value but lower than the lower boundary value, and the wind power adjustment of reserve power can meet the active power demand deficit, the response control mode is determined to be the energy storage response control mode; or, when the charge state of the energy storage system is higher than or equal to the lower boundary value, the response control mode is determined to be the energy storage response control mode, wherein the lower limit value is the charge state value when the energy storage system has finished discharging, and the lower boundary value is higher than the lower limit value.

[0008] Optionally, the step of continuously controlling the charging or discharging of the wind farm's energy storage system during the second control cycle based on the active power demand deficit includes: when the active power demand deficit is less than 0 and the absolute value of the active power demand deficit is greater than the maximum allowable charging power of the energy storage system, controlling the energy storage system to continuously charge at the maximum allowable charging power during the second control cycle; when the active power demand deficit is less than 0 and the absolute value of the active power demand deficit is less than the maximum allowable charging power of the energy storage system, controlling the energy storage system to continuously charge at the absolute value of the active power demand deficit during the second control cycle; when the active power demand deficit is greater than 0 and the active power demand deficit is greater than the maximum allowable discharging power of the energy storage system, controlling the energy storage system to continuously discharge at the maximum allowable discharging power during the second control cycle; when the active power demand deficit is greater than 0 and the active power demand deficit is less than the maximum allowable discharging power of the energy storage system, controlling the energy storage system to continuously discharge according to the active power demand deficit during the second control cycle.

[0009] Optionally, the steps for obtaining the active power demand deficit for primary frequency regulation of a wind farm include: obtaining the active power target value that the wind farm needs to achieve for primary frequency regulation and the actual active power value at the grid connection point; and using the difference between the active power target value and the actual active power value as the active power demand deficit for primary frequency regulation of the wind farm.

[0010] Optionally, the adjustable reserve power of wind power includes: wind power upward reserve power and wind power downward reserve power; wherein, the wind power upward reserve power is determined based on the wind turbine generator set of the wind farm using pitch adjustment, inertia adjustment, and rotor kinetic energy adjustment; wherein, the wind power downward reserve power is determined based on the wind turbine generator set of the wind farm using pitch adjustment, inertia adjustment, and braking resistor adjustment.

[0011] According to a second aspect of the present disclosure, a primary frequency regulation control device for a wind farm is provided, comprising: an acquisition unit configured to acquire the active power demand deficit of the primary frequency regulation of the wind farm, the wind power adjustable reserve power of the wind farm, and the charge state of the energy storage system; a mode determination unit configured to determine a response control mode based on the active power demand deficit, the wind power adjustable reserve power, and the charge state of the energy storage system; a wind power control unit configured to, when the determined response control mode is a wind power response control mode, continuously control the wind turbine generators of the wind farm to adjust the active power based on the active power demand deficit and the wind power adjustable reserve power during a first control period; and an energy storage control unit configured to, when the determined response control mode is an energy storage response control mode, continuously control the energy storage system of the wind farm to charge or discharge based on the active power demand deficit during a second control period; wherein the first control period is longer than the second control period.

[0012] Optionally, when the active power demand deficit is less than 0, the mode determination unit is configured to: determine the response control mode as wind power response control mode when the energy storage system is in a charging lockout state or when the energy storage system's charge state is higher than or equal to the upper limit value; determine the response control mode as wind power response control mode when the energy storage system's charge state is higher than the upper boundary value but lower than the upper limit value, and the wind power's reduced reserve power can meet the active power demand deficit; determine the response control mode as energy storage response control mode when the energy storage system's charge state is higher than the upper boundary value but lower than the upper limit value, and the wind power's reduced reserve power cannot meet the active power demand deficit; or, determine the response control mode as energy storage response control mode when the energy storage system's charge state is lower than or equal to the upper boundary value, wherein the upper limit value is the charge state value when the energy storage system is fully charged, and the upper boundary value is lower than the upper limit value.

[0013] Optionally, when the active power demand deficit is greater than 0, the mode determination unit is configured to: determine the response control mode as wind power response control mode when the energy storage system is in a discharge lockout state or the energy storage system charge state is lower than or equal to the lower limit value; determine the response control mode as wind power response control mode when the energy storage system charge state is higher than the lower limit value but lower than the lower boundary value, and the wind power increase in reserve power can meet the active power demand deficit; determine the response control mode as energy storage response control mode when the energy storage system charge state is higher than the lower limit value but lower than the lower boundary value, and the wind power increase in reserve power cannot meet the active power demand deficit; or, determine the response control mode as energy storage response control mode when the energy storage system charge state is higher than or equal to the lower boundary value, wherein the lower limit value is the charge state value when the energy storage system has finished discharging, and the lower boundary value is higher than the lower limit value.

[0014] Optionally, the energy storage control unit is configured to: when the active power demand deficit is less than 0 and the absolute value of the active power demand deficit is greater than the maximum allowable charging power of the energy storage system, control the energy storage system to continuously charge at the maximum allowable charging power during the second control cycle; when the active power demand deficit is less than 0 and the absolute value of the active power demand deficit is less than the maximum allowable charging power of the energy storage system, control the energy storage system to continuously charge at the absolute value of the active power demand deficit during the second control cycle; when the active power demand deficit is greater than 0 and the active power demand deficit is greater than the maximum allowable discharging power of the energy storage system, control the energy storage system to continuously discharge at the maximum allowable discharging power during the second control cycle; when the active power demand deficit is greater than 0 and the active power demand deficit is less than the maximum allowable discharging power of the energy storage system, control the energy storage system to continuously discharge at the active power demand deficit during the second control cycle.

[0015] Optionally, the acquisition unit is configured to: acquire the active power target value that the wind farm needs to achieve for primary frequency regulation and the actual active power value at the grid connection point; and use the difference between the active power target value and the actual active power value as the active power demand deficit for the wind farm's primary frequency regulation.

[0016] Optionally, the adjustable reserve power of wind power includes: wind power upward reserve power and wind power downward reserve power; wherein, the wind power upward reserve power is determined based on the wind turbine generator set of the wind farm using pitch adjustment, inertia adjustment, and rotor kinetic energy adjustment; wherein, the wind power downward reserve power is determined based on the wind turbine generator set of the wind farm using pitch adjustment, inertia adjustment, and braking resistor adjustment.

[0017] Optionally, the primary frequency control device is located in the controller of the wind farm.

[0018] According to a third aspect of the present disclosure, a computer-readable storage medium storing a computer program is provided, which, when executed by a processor, causes the processor to perform the primary frequency regulation control method for a wind farm as described above.

[0019] According to a fourth aspect of the present disclosure, a primary frequency regulation control device for a wind farm is provided, the primary frequency regulation control device comprising: a processor; and a memory storing a computer program, wherein when the computer program is executed by the processor, the processor is prompted to execute the primary frequency regulation control method for the wind farm as described above.

[0020] Optionally, the primary frequency control device is located in the controller of the wind farm.

[0021] The primary frequency regulation control method and apparatus for wind farms according to the exemplary embodiments of this disclosure can effectively and reasonably coordinate and control the wind turbine generators and energy storage systems of the wind farm to participate in the primary frequency regulation of the power grid.

[0022] Furthermore, the coordinated control method of energy storage frequency regulation and wind power frequency regulation disclosed herein can bring the following benefits: it eliminates the need to activate the "low-frequency standby" function of the wind farm, thereby increasing the economic benefits of the new energy power plant; it reduces the number of wind turbine actions near the frequency regulation dead zone boundary, thereby improving safety; and it improves the response speed and accuracy of the wind farm's participation in the primary frequency regulation response, thereby increasing the response time coverage dimension.

[0023] Further aspects and / or advantages of the general concept of this disclosure will be set forth in part in the description which follows, and in part will be clear from the description or may be learned by practice of the general concept of this disclosure. Attached Figure Description

[0024] The above and other objects and features of exemplary embodiments of this disclosure will become clearer from the following description taken in conjunction with the accompanying drawings, which exemplarily illustrate the embodiments, wherein:

[0025] Figure 1 The topology of a wind farm according to an exemplary embodiment of the present disclosure is shown;

[0026] Figure 2 An example of primary frequency modulation droop control according to an exemplary embodiment of the present disclosure is shown;

[0027] Figure 3 An example of a single-frequency step response according to an exemplary embodiment of the present disclosure is shown;

[0028] Figure 4 A flowchart illustrating a primary frequency regulation control method for a wind farm according to an exemplary embodiment of the present disclosure is shown.

[0029] Figure 5 A control logic diagram of an overfrequency control scenario according to an exemplary embodiment of the present disclosure is shown;

[0030] Figure 6 A control logic diagram of an underfrequency control scenario according to an exemplary embodiment of the present disclosure is shown;

[0031] Figure 7 A structural block diagram of a primary frequency regulation control device for a wind farm according to an exemplary embodiment of the present disclosure is shown. Detailed Implementation

[0032] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings, examples of which are illustrated in the drawings, wherein the same reference numerals always refer to the same parts. The embodiments will now be described with reference to the accompanying drawings in order to explain this disclosure.

[0033] Figure 1 The topology of a wind farm according to an exemplary embodiment of the present disclosure is shown.

[0034] Reference Figure 1 Wind farm level controller (e.g., Figure 1 The wind farm's control system (as the top-level control device) monitors grid connection point data (e.g., data collected by voltage transformers (PTs) and current transformers (CTs), and centrally controls the energy storage system and all wind turbine generators (also simply called wind turbines). The wind farm's site-level controller can achieve primary frequency regulation by uniformly scheduling all wind turbine generators and the energy storage system, and comprehensively controlling them. For example, the energy storage system may include batteries, an energy management system (EMS), a power converter system (PCS), a battery management system (BMS), and other electrical equipment.

[0035] As an example, under high-frequency disturbances in the wind farm grid, the primary frequency regulation action can be adjusted downwards after reaching 10% of the rated output; under low-frequency disturbances in the grid, the primary frequency regulation action can be adjusted upwards after reaching 6% of the rated output (10% and 6% are recommended values). The primary frequency regulation droop characteristic is achieved through a piecewise linear function of the set frequency and active power, i.e.:

[0036]

[0037] Where P represents the active power target value to be achieved in a single frequency regulation, in MW; f d Indicates the dead zone of a single frequency modulation, in Hz; f N P represents the rated frequency of the power grid system, in Hz. N The rated power is expressed in MW; δ% represents the primary frequency regulation coefficient of new energy sources; P0 represents the initial value of active power, expressed in MW.

[0038] For example, the primary frequency modulation dead zone is set to 0.05Hz, the droop factor is set to 5%, and the maximum power limit for primary frequency modulation is set to 6%P. N The maximum power limit for frequency modulation is set to 10%P. N In this case, the droop curve of wind farm participation in grid primary frequency regulation can be shown as follows: Figure 2 As shown.

[0039] Figure 3 An example of a single-frequency step response according to an exemplary embodiment of the present disclosure is shown. (Refer to...) Figure 3 The frequency modulation step response parameters are as follows: start time t0; start time t d Response time t up Adjustment time t s Rated power P N ; Target power adjustment amount ΔP.

[0040] Figure 4 A flowchart illustrating a primary frequency regulation control method for a wind farm according to an exemplary embodiment of the present disclosure is shown.

[0041] As an example, the primary frequency regulation control method of a wind farm according to an exemplary embodiment of the present disclosure can be executed by the wind farm's control equipment, for example, the wind farm's control equipment can be a wind farm controller (i.e., a wind farm-level controller).

[0042] A wind farm may include an energy storage system and multiple wind turbine generators. Both the wind turbine generators and the energy storage system of the wind farm are connected to the power grid through appropriate means.

[0043] Reference Figure 4 In step S10, the active power demand deficit of the primary frequency regulation of the wind farm, the wind power adjustable reserve power of the wind farm, and the charge status of the energy storage system are obtained.

[0044] The active power demand deficit for primary frequency regulation of a wind farm is the increase in active power that the wind farm needs to regulate. It should be understood that the active power demand deficit for primary frequency regulation of a wind farm can be greater than 0 or less than 0. A deficit greater than 0 means the wind farm needs to increase its active power output, while a deficit less than 0 means the wind farm needs to decrease its active power output.

[0045] As an example, the steps to obtain the active power demand deficit for primary frequency regulation of a wind farm may include: obtaining the active power target value that the wind farm needs to achieve for primary frequency regulation and the actual active power value at the wind farm's grid connection point; and using the difference between the active power target value and the actual active power value as the active power demand deficit for primary frequency regulation of the wind farm.

[0046] As an example, the active power target value that a wind farm needs to achieve for primary frequency regulation can be calculated using equation (1).

[0047] In step S20, the response control mode is determined based on the active power demand deficit, the adjustable reserve power of wind power, and the charge status of the energy storage system.

[0048] Adjustable wind power reserve can include: wind power upward reserve and wind power downward reserve. Wind power upward reserve refers to the total active power that can be increased through the various wind turbine generators in the wind farm, while wind power downward reserve refers to the total active power that can be reduced through the various wind turbine generators in the wind farm.

[0049] The State of Charge (SOC) of an energy storage system reflects the remaining capacity of the battery. It is numerically defined as the ratio of the remaining capacity to the battery capacity, and is usually expressed as a percentage.

[0050] As an example, when the active power demand deficit is less than 0, it corresponds to an over-frequency control scenario. In the over-frequency control scenario, step S20 may include: when the energy storage system is in a charging lockout state, or when the energy storage system's charge state is higher than or equal to the upper limit value, determining the response control mode as a wind power response control mode; when the energy storage system's charge state is higher than the upper boundary value but lower than the upper limit value, and the wind power's reduced reserve power can meet the active power demand deficit, determining the response control mode as a wind power response control mode; when the energy storage system's charge state is higher than the upper boundary value but lower than the upper limit value, and the wind power's reduced reserve power cannot meet the active power demand deficit, determining the response control mode as an energy storage response control mode; or, when the energy storage system's charge state is lower than or equal to the upper boundary value, determining the response control mode as an energy storage response control mode. For example, refer to... Figure 5 .

[0051] The upper limit value is the state of charge (SOC) value when the energy storage system is fully charged; in other words, when this value is reached, it indicates that the energy storage system's battery is fully charged. The upper boundary value is lower than the upper limit value; for example, the upper boundary value could be the SOC value when the battery is not fully charged but is close to being fully charged.

[0052] Charging lockout refers to a situation where an energy storage system cannot be charged due to the battery being fully charged or a malfunction.

[0053] When the active power demand deficit is less than 0, the reduction of wind power reserve capacity can meet the active power demand deficit, that is, the absolute value of the reduction of wind power reserve capacity is greater than or equal to the absolute value of the active power demand deficit.

[0054] As an example, when the active power demand deficit is greater than 0, it corresponds to an underfrequency control scenario. In the underfrequency control scenario, step S20 may include: when the energy storage system is in a discharge-locked state, or when the energy storage system's charge state is lower than or equal to the lower limit, determining the response control mode as a wind power response control mode; when the energy storage system's charge state is higher than the lower limit but lower than the lower boundary value, and the wind power's increased reserve power can meet the active power demand deficit, determining the response control mode as a wind power response control mode; when the energy storage system's charge state is higher than the lower limit but lower than the lower boundary value, and the wind power's increased reserve power cannot meet the active power demand deficit, determining the response control mode as an energy storage response control mode; or, when the energy storage system's charge state is higher than or equal to the lower boundary value, determining the response control mode as an energy storage response control mode. For example, refer to... Figure 6 .

[0055] The lower limit value is the state of charge (SOC) value when the energy storage system is fully discharged; in other words, when this value is reached, it indicates that the battery is completely discharged. The lower boundary value is higher than the lower limit value; for example, the lower boundary value could be the SOC value when the battery is not fully discharged but is close to being fully discharged.

[0056] Discharge lockout refers to the energy storage system being unable to discharge due to reasons such as the battery being fully charged or a malfunction. When the active power demand deficit is greater than 0, the wind power's reserve power adjustment can meet the active power demand deficit, that is, the wind power's reserve power adjustment is greater than or equal to the active power demand deficit.

[0057] Under normal circumstances, the SOC (State of Charge) of energy storage systems is in a good state. Considering the rapid and precise response characteristics of energy storage systems, when the SOC is sufficient, the energy storage system should be utilized as much as possible to respond to demand. During over-frequency operation, the energy storage system is controlled to charge to reduce power at the grid connection point; during under-frequency operation, the energy storage system is controlled to discharge to increase power at the grid connection point. Considering that other systems' control or manual control may not fully cover the SOC, when participating in the primary frequency regulation response of the grid, while taking the SOC status into account, it is necessary to both meet the grid frequency response and maximize the SOC to a good state. When approaching the upper and lower limits of the SOC, the energy storage system should be kept at a reasonable position, adjustable both upwards and downwards, without reaching the maximum / minimum limits. To avoid grid interruption, the principle of prioritizing wind power response is adopted.

[0058] Wind power (i.e., wind turbine generators) and energy storage (i.e., energy storage systems) are prioritized for dispatch in different scenarios. Both wind power and energy storage reserve a portion of their capacity, avoiding boundary-based control. This ensures efficient resource allocation and responsiveness in every dispatch, improving control accuracy and ultimately achieving short response times and high control precision. Wind power is only considered when its reserve capacity is sufficient. The energy storage system's State of Charge (SOC) reserves space at both maximum and minimum values. Only when wind power reserve capacity is insufficient will the energy storage system's capacity between boundary and limit values ​​be activated. This approach aims to rationally allocate resources between wind power and energy storage. On one hand, it meets the requirements of primary frequency regulation; on the other hand, it ensures that energy storage always reserves a portion of its capacity. When wind power capacity is sufficient, wind power output is utilized as much as possible. This reserved capacity of the energy storage system is readily available for other control functions (such as active power control and power prediction correction), achieving rational resource allocation.

[0059] In step S30, when the determined response control mode is the wind power response control mode, the active power of the wind turbine generator set of the wind farm is continuously controlled to adjust the active power based on the active power demand deficit and the wind power adjustable reserve power during the first control cycle.

[0060] It should be understood that the active power output of wind turbine generators in wind farms can be adjusted in an appropriate manner based on the active power demand deficit and the adjustable reserve power of wind power, and this disclosure does not limit this.

[0061] As an example, after continuously controlling the wind turbine generators of the wind farm to adjust the active power during the first control cycle, the process can return to step S10 (for example, updating the active power target value that the wind farm needs to achieve for primary frequency regulation based on the updated frequency of the grid connection point and the updated actual active power value of the grid connection point, updating the active power demand deficit of the wind farm for primary frequency regulation, and updating the wind farm's adjustable reserve power and energy storage system charge status), and then execute the subsequent step S20, and then execute step S30 or step S40.

[0062] In step S40, when the determined response control mode is the energy storage response control mode, the energy storage system of the wind farm is continuously controlled to charge or discharge during the second control cycle based on the active power demand deficit.

[0063] As an example, after continuously controlling the charging or discharging of the wind farm's energy storage system during the second control cycle, the process can return to step S10 (e.g., updating the active power target value that the wind farm needs to achieve for primary frequency regulation based on the updated frequency of the grid connection point and the updated actual active power value of the grid connection point, updating the active power demand deficit of the wind farm's primary frequency regulation, and updating the wind farm's adjustable reserve power and the charge status of the energy storage system), and then execute the subsequent step S20, and then execute step S30 or step S40.

[0064] As an example, the first control cycle can be longer than the second control cycle.

[0065] This disclosure takes into account the different response speeds of wind power and energy storage. Energy storage has a fast response speed, while wind power has a slow response speed. If they respond together, when judging the response result of a control cycle, we can only wait for the slower response to arrive before we can finally judge whether the adjustment is in place and how much it is still far from the target value. Thus, the final control speed is limited by the slower response of wind power. Therefore, this disclosure proposes that wind power and energy storage respond separately. At any given time, either wind power or energy storage should respond. After one control cycle, the control effect is judged. In the next cycle, the control is performed again based on the wind power reserve capacity, the energy storage SOC, and the actual power deficit. In the next control cycle, the optimal response control mode is still selected, and periodic closed-loop control is performed to achieve the control target as quickly as possible, achieving the goal of fast response speed and high control accuracy.

[0066] As an example, the charging or discharging power of the energy storage system can be controlled based on the active power demand deficit, the maximum allowable charging power of the energy storage system, and the maximum allowable discharging power of the energy storage system.

[0067] As a first example, the steps of continuously controlling the charging or discharging of the energy storage system of the wind farm based on the active power demand deficit during the second control cycle may include: when the active power demand deficit is less than 0 and the absolute value of the active power demand deficit is greater than the maximum allowable charging power of the energy storage system, controlling the energy storage system to continuously charge at the maximum allowable charging power during the second control cycle.

[0068] As a second example, the steps for continuously controlling the charging or discharging of the wind farm's energy storage system based on the active power demand deficit during the second control cycle may include: when the active power demand deficit is less than 0, and the absolute value of the active power demand deficit is less than the maximum allowable charging power of the energy storage system, controlling the energy storage system to continuously charge according to the absolute value of the active power demand deficit during the second control cycle. Controlling the energy storage system to charge according to the absolute value of the active power demand deficit means controlling the charging power of the energy storage system to be the absolute value of the active power demand deficit.

[0069] As a third example, the steps of continuously controlling the charging or discharging of the energy storage system of the wind farm based on the active power demand deficit during the second control cycle may include: when the active power demand deficit is greater than 0 and the active power demand deficit is greater than the maximum allowable discharge power of the energy storage system, controlling the energy storage system to continuously discharge at the maximum allowable discharge power during the second control cycle.

[0070] As a fourth example, the steps of continuously controlling the charging or discharging of the energy storage system of the wind farm based on the active power demand deficit during the second control cycle may include: when the active power demand deficit is greater than 0 and the active power demand deficit is less than the maximum allowable discharge power of the energy storage system, controlling the energy storage system to continuously discharge according to the active power demand deficit during the second control cycle.

[0071] The maximum permissible charging power of an energy storage system refers to the maximum rate at which the energy storage battery can store electrical energy. The maximum permissible discharging power of an energy storage system refers to the maximum rate at which the energy storage battery can release electrical energy.

[0072] According to an exemplary embodiment of this disclosure, when the energy storage SOC is relatively good, the energy storage system battery can release / store electricity at the maximum speed to prioritize frequency regulation requirements. When the active power demand deficit is greater than the maximum SOC charging rate, segmented control can be adopted to ensure that the maximum SOC charging rate is not exceeded.

[0073] As an example, the primary frequency regulation control method for a wind farm according to an exemplary embodiment of the present disclosure may further include: determining the wind power reserve capacity and the wind power reserve capacity of the wind farm.

[0074] As an example, the reserve power adjustment for wind power can be determined based on the pitch adjustment method, inertia adjustment method, and rotor kinetic energy adjustment method of each wind turbine in the wind farm. Pitch adjustment method refers to the amount of active power that can be increased by the wind turbine through pitch control; rotor kinetic energy adjustment method refers to the amount of active power that can be increased by changing the rotor kinetic energy; inertia adjustment method refers to the amount of active power that can be increased by the inertia. As an example, the inertia adjustment method can be determined based on the turbine's inertia coefficient, rated power, and current actual power.

[0075] For example, the reserve power increase through pitch control in a wind farm can be the sum of the reserve power increases through pitch control of all wind turbine generators within the wind farm. Similarly, the reserve power increase through inertia control can be the sum of the reserve power increases through inertia control of all wind turbine generators within the wind farm. Likewise, the reserve power increase through rotor kinetic energy control can be the sum of the reserve power increases through rotor kinetic energy control of all wind turbine generators within the wind farm. Therefore, the total reserve power increase for a wind farm can be the sum of the reserve power increases through pitch control, inertia control, and rotor kinetic energy control—that is, the total reserve power increase from all wind turbine generators in the wind farm.

[0076] As an example, the reserve power reduction for wind turbines can be determined based on the pitch reduction method, inertia reduction method, and braking resistor reduction method for each wind turbine in a wind farm. Pitch reduction refers to the amount of active power that can be reduced by the wind turbine through pitch control; braking resistor reduction refers to the amount of active power that can be reduced by the wind turbine through braking resistor consumption; and inertia reduction refers to the amount of active power that can be reduced by the wind turbine through inertia. As an example, the inertia reduction method can be determined based on the turbine's inertia coefficient, rated power, and current actual power.

[0077] For example, the reserve power reduction under pitch control in a wind farm can be the sum of the reserve power reductions under pitch control for all wind turbine generators within the wind farm. Similarly, the reserve power reduction under inertia control in a wind farm can be the sum of the reserve power reductions under inertia control for all wind turbine generators within the wind farm. Finally, the total reserve power reduction for a wind farm can be the sum of the reserve power reductions under pitch control, inertia control, and braking resistor control methods.

[0078] In related technologies, when the grid frequency is under-regulated, new energy sources need to have the function of primary frequency regulation to increase power output. However, wind power lacks this capability in non-curtailment modes. Therefore, new energy power plants need to continuously operate with "low-frequency backup" functionality, keeping wind farms in a curtailment mode for extended periods, which severely impacts the economic benefits of new energy power plants. This disclosure considers that energy storage has the characteristics of rapid and accurate response, and its participation in primary frequency regulation can effectively improve the grid frequency quality. Therefore, by utilizing energy storage to participate in frequency regulation, the "low-frequency backup" function can be avoided, thereby improving the economic benefits of new energy power plants.

[0079] In related technologies, many wind power projects experience frequent grid frequency fluctuations, coupled with a small primary frequency regulation dead zone (approximately between 0.015 and 0.034), operating mostly near the dead zone boundary. Small high-frequency disturbances causing this phenomenon result in frequent wind turbine operation in primary frequency regulation. To reduce wear on wind turbines, this disclosure proposes energy storage frequency regulation to adjust frequency fluctuations near the primary frequency regulation dead zone, minimizing the number of wind turbine operations and thus improving the economic efficiency of wind turbine operation.

[0080] According to an exemplary embodiment of this disclosure, taking battery-type energy storage as an example, the over-limit region is described by the characteristics of the energy storage device's ability to absorb / release power (i.e., SOC). That is, the region from the upper boundary value to the upper limit value and the region from the lower boundary value to the lower limit value. The over-limit region is determined by the battery type of the energy storage system, as well as considerations such as energy storage system failure and safety. Therefore, some operating conditions of energy storage systems do not have the ability to participate in primary frequency regulation.

[0081] According to an exemplary embodiment of this disclosure, the primary frequency regulation control process takes into account the SOC of the energy storage system, thereby increasing the available space of the SOC and improving the primary frequency regulation response time coverage of the wind farm.

[0082] Figure 7 A structural block diagram of a primary frequency regulation control device for a wind farm according to an exemplary embodiment of the present disclosure is shown.

[0083] like Figure 7 As shown, the primary frequency regulation control device for a wind farm according to an exemplary embodiment of the present disclosure includes: an acquisition unit 10, a mode determination unit 20, a wind power control unit 30, and an energy storage control unit 40.

[0084] Specifically, the acquisition unit 10 is configured to acquire the active power demand deficit of the primary frequency regulation of the wind farm, the wind power adjustable reserve power of the wind farm, and the charge status of the energy storage system.

[0085] The mode determination unit 20 is configured to determine the response control mode based on the active power demand deficit, the adjustable reserve power of wind power, and the charge status of the energy storage system.

[0086] The wind power control unit 30 is configured to continuously control the wind turbine generators of the wind farm to adjust the active power during the first control cycle when the determined response control mode is the wind power response control mode, based on the active power demand deficit and the wind power adjustable reserve power.

[0087] The energy storage control unit 40 is configured to continuously control the energy storage system of the wind farm to charge or discharge during the second control cycle based on the active power demand deficit when the determined response control mode is the energy storage response control mode; the first control cycle is longer than the second control cycle.

[0088] As an example, when the active power demand deficit is less than 0, the mode determination unit 20 can be configured to: determine the response control mode as wind power response control mode when the energy storage system is in a charging lockout state or when the energy storage system's charge state is higher than or equal to the upper limit value; determine the response control mode as wind power response control mode when the energy storage system's charge state is higher than the upper boundary value but lower than the upper limit value, and the wind power's reduced reserve power can meet the active power demand deficit; determine the response control mode as energy storage response control mode when the energy storage system's charge state is higher than the upper boundary value but lower than the upper limit value, and the wind power's reduced reserve power cannot meet the active power demand deficit; or, determine the response control mode as energy storage response control mode when the energy storage system's charge state is lower than or equal to the upper boundary value, wherein the upper limit value is the charge state value when the energy storage system is fully charged, and the upper boundary value is lower than the upper limit value.

[0089] As an example, when the active power demand deficit is greater than 0, the mode determination unit 20 can be configured to: determine the response control mode as wind power response control mode when the energy storage system is in a discharge lockout state or the energy storage system charge state is lower than or equal to the lower limit value; determine the response control mode as wind power response control mode when the energy storage system charge state is higher than the lower limit value but lower than the lower boundary value, and the wind power increase in reserve power can meet the active power demand deficit; determine the response control mode as energy storage response control mode when the energy storage system charge state is higher than the lower limit value but lower than the lower boundary value, and the wind power increase in reserve power cannot meet the active power demand deficit; or, determine the response control mode as energy storage response control mode when the energy storage system charge state is higher than or equal to the lower boundary value, wherein the lower limit value is the charge state value when the energy storage system has finished discharging, and the lower boundary value is higher than the lower limit value.

[0090] As an example, the energy storage control unit 40 can be configured to: when the active power demand deficit is less than 0 and the absolute value of the active power demand deficit is greater than the maximum allowable charging power of the energy storage system, control the energy storage system to continuously charge at the maximum allowable charging power during the second control cycle; when the active power demand deficit is less than 0 and the absolute value of the active power demand deficit is less than the maximum allowable charging power of the energy storage system, control the energy storage system to continuously charge at the absolute value of the active power demand deficit during the second control cycle; when the active power demand deficit is greater than 0 and the active power demand deficit is greater than the maximum allowable discharging power of the energy storage system, control the energy storage system to continuously discharge at the maximum allowable discharging power during the second control cycle; when the active power demand deficit is greater than 0 and the active power demand deficit is less than the maximum allowable discharging power of the energy storage system, control the energy storage system to continuously discharge at the active power demand deficit during the second control cycle.

[0091] As an example, the acquisition unit 10 can be configured to: acquire the active power target value that the wind farm needs to achieve for primary frequency regulation and the actual active power value at the grid connection point; and use the difference between the active power target value and the actual active power value as the active power demand deficit for the wind farm's primary frequency regulation.

[0092] As an example, the adjustable reserve power of wind power may include: wind power upward reserve power and wind power downward reserve power; wherein, the wind power upward reserve power is determined based on the wind turbine generators of the wind farm using pitch adjustment, inertia adjustment, and rotor kinetic energy adjustment; wherein, the wind power downward reserve power is determined based on the wind turbine generators of the wind farm using pitch adjustment, inertia adjustment, and braking resistor adjustment.

[0093] As an example, a primary frequency regulation control device for a wind farm according to an exemplary embodiment of the present disclosure may be provided in a wind farm controller.

[0094] It should be understood that the specific processing performed by the primary frequency regulation control device of the wind farm according to the exemplary embodiments of this disclosure has been referenced. Figures 1 to 6 A detailed description has been provided, and the relevant details will not be repeated here.

[0095] It should be understood that the various units in the primary frequency control device of the wind farm according to the exemplary embodiments of this disclosure can be implemented as hardware components and / or software components. Those skilled in the art can implement the various units, for example, using field-programmable gate arrays (FPGAs) or application-specific integrated circuits (ASICs), based on the processes performed by the defined various units.

[0096] An exemplary embodiment of this disclosure provides a computer-readable storage medium storing a computer program that, when executed by a processor, causes the processor to perform a primary frequency regulation control method for a wind farm as described in the exemplary embodiment above. The computer-readable storage medium is any data storage device capable of storing data readable by a computer system. Examples of computer-readable storage media include: read-only memory, random access memory, read-only optical disk, magnetic tape, floppy disk, optical data storage device, and carrier waves (such as data transmission via the Internet through wired or wireless transmission paths).

[0097] A primary frequency regulation control device for a wind farm according to an exemplary embodiment of the present disclosure includes a processor (not shown) and a memory (not shown), wherein the memory stores a computer program that, when executed by the processor, causes the processor to perform a primary frequency regulation control method for a wind farm as described in the exemplary embodiment above.

[0098] As an example, a primary frequency regulation control device for a wind farm according to an exemplary embodiment of the present disclosure may be provided in a wind farm controller.

[0099] While some exemplary embodiments of this disclosure have been shown and described, those skilled in the art will understand that modifications may be made to these embodiments without departing from the principles and spirit of this disclosure, which are defined by the claims and their equivalents.

Claims

1. A primary frequency regulation control method for a wind farm, characterized in that, include: Obtain the active power demand deficit of the primary frequency regulation of the wind farm, the wind power adjustable reserve power of the wind farm, and the charge status of the energy storage system; Based on the active power demand deficit, the adjustable reserve power of wind power, and the charge status of the energy storage system, the response control mode is determined. When the determined response control mode is wind power response control mode, based on the active power demand deficit and wind power adjustable reserve power, the wind turbine generators of the wind farm are continuously controlled to adjust the active power during the first control cycle. When the determined response control mode is the energy storage response control mode, based on the active power demand deficit, the energy storage system of the wind farm is continuously controlled to charge or discharge during the second control cycle; the first control cycle is longer than the second control cycle. When the active power demand deficit is greater than 0, the steps for determining the response control mode based on the active power demand deficit, the adjustable reserve power of wind power, and the charge state of the energy storage system include: When the charge state of the energy storage system is higher than the lower limit and lower than the lower boundary value, the response control mode is determined based on whether the wind power increase in reserve power can meet the active power demand deficit. Specifically, when the wind power increase in reserve power can meet the active power demand deficit, the response control mode is determined to be the wind power response control mode, and when the wind power increase in reserve power cannot meet the active power demand deficit, the response control mode is determined to be the energy storage response control mode. When the charge state of the energy storage system is higher than or equal to the lower boundary value, the response control mode is determined to be the energy storage response control mode. or, When the active power demand deficit is less than 0, the steps for determining the response control mode based on the active power demand deficit, the adjustable reserve power of wind power, and the charge state of the energy storage system include: When the charge state of the energy storage system is higher than the upper boundary value but lower than the upper limit value, the response control mode is determined based on whether the wind power reduction of reserve power can meet the active power demand deficit. Specifically, when the wind power reduction of reserve power can meet the active power demand deficit, the response control mode is determined to be the wind power response control mode; when the wind power reduction of reserve power cannot meet the active power demand deficit, the response control mode is determined to be the energy storage response control mode. When the charge state of the energy storage system is lower than or equal to the upper boundary value, the response control mode is determined to be the energy storage response control mode. The upper limit value is the charge state value of the energy storage system when it is fully charged, and the upper boundary value is lower than the upper limit value. The lower limit value is the charge state value of the energy storage system when it is fully discharged, and the lower boundary value is higher than the lower limit value.

2. The primary frequency modulation control method according to claim 1, characterized in that, When the active power demand deficit is less than 0, the steps for determining the response control mode based on the active power demand deficit, the adjustable reserve power of wind power, and the charge state of the energy storage system also include: When the energy storage system is in a charging lockout state, or when the energy storage system's charge state is higher than or equal to the upper limit value, the response control mode is determined to be the wind power response control mode.

3. The primary frequency modulation control method according to claim 1, characterized in that, When the active power demand deficit is greater than 0, the steps for determining the response control mode based on the active power demand deficit, the adjustable reserve power of wind power, and the charge state of the energy storage system also include: When the energy storage system is in a discharge lockout state, or when the energy storage system's charge state is lower than or equal to the lower limit, the response control mode is determined to be the wind power response control mode.

4. The primary frequency modulation control method according to claim 1, characterized in that, Based on the active power demand deficit, the steps for continuously controlling the charging or discharging of the wind farm's energy storage system during the second control cycle include: When the active power demand deficit is less than 0 and the absolute value of the active power demand deficit is greater than the maximum allowable charging power of the energy storage system, the energy storage system is controlled to continuously charge at the maximum allowable charging power during the second control cycle. When the active power demand deficit is less than 0 and the absolute value of the active power demand deficit is less than the maximum allowable charging power of the energy storage system, the energy storage system is controlled to continuously charge according to the absolute value of the active power demand deficit during the second control cycle. When the active power demand deficit is greater than 0 and the active power demand deficit is greater than the maximum allowable discharge power of the energy storage system, the energy storage system is controlled to continuously discharge at the maximum allowable discharge power during the second control cycle. When the active power demand deficit is greater than 0 and less than the maximum allowable discharge power of the energy storage system, the energy storage system is controlled to continuously discharge according to the active power demand deficit during the second control cycle.

5. The primary frequency modulation control method according to claim 1, characterized in that, The steps to obtain the active power demand deficit for primary frequency regulation of a wind farm include: Obtain the active power target value that the wind farm needs to achieve for primary frequency regulation and the actual active power value at the grid connection point; The difference between the target active power value and the actual active power value is used as the active power demand deficit for primary frequency regulation of the wind farm.

6. The primary frequency modulation control method according to claim 1, characterized in that, Adjustable wind power reserve capacity includes: wind power upward adjustment reserve capacity and wind power downward adjustment reserve capacity; The adjustment of reserve power for wind power is determined based on the adjustment methods of pitch control, inertia, and rotor kinetic energy for each wind turbine generator unit in the wind farm. The reduction in reserve power for wind power is determined based on the reduction of reserve power by pitch control, inertia control, and braking resistor control for each wind turbine generator unit in the wind farm.

7. A primary frequency regulation control device for a wind farm, characterized in that, include: The acquisition unit is configured to acquire the active power demand deficit of the primary frequency regulation of the wind farm, the wind power adjustable reserve power of the wind farm, and the charge status of the energy storage system. The mode determination unit is configured to determine the response control mode based on the active power demand deficit, the adjustable reserve power of wind power, and the charge state of the energy storage system. The wind power control unit is configured to continuously control the wind turbine generators of the wind farm to adjust the active power during the first control cycle when the determined response control mode is the wind power response control mode, based on the active power demand deficit and the wind power adjustable reserve power. The energy storage control unit is configured to continuously control the charging or discharging of the wind farm's energy storage system during the second control cycle, based on the active power demand deficit, when the determined response control mode is the energy storage response control mode; the first control cycle is longer than the second control cycle. When the active power demand deficit is greater than 0, the mode determination unit is configured as follows: When the charge state of the energy storage system is higher than the lower limit and lower than the lower boundary value, the response control mode is determined based on whether the wind power increase in reserve power can meet the active power demand deficit. Specifically, when the wind power increase in reserve power can meet the active power demand deficit, the response control mode is determined to be the wind power response control mode, and when the wind power increase in reserve power cannot meet the active power demand deficit, the response control mode is determined to be the energy storage response control mode. When the charge state of the energy storage system is higher than or equal to the lower boundary value, the response control mode is determined to be the energy storage response control mode. or, When the active power demand deficit is less than 0, the mode determination unit is configured as follows: When the charge state of the energy storage system is higher than the upper boundary value but lower than the upper limit value, the response control mode is determined based on whether the wind power reduction of reserve power can meet the active power demand deficit. Specifically, when the wind power reduction of reserve power can meet the active power demand deficit, the response control mode is determined to be the wind power response control mode; when the wind power reduction of reserve power cannot meet the active power demand deficit, the response control mode is determined to be the energy storage response control mode. When the charge state of the energy storage system is lower than or equal to the upper boundary value, the response control mode is determined to be the energy storage response control mode. The upper limit value is the charge state value of the energy storage system when it is fully charged, and the upper boundary value is lower than the upper limit value. The lower limit value is the charge state value of the energy storage system when it is fully discharged, and the lower boundary value is higher than the lower limit value.

8. The primary frequency modulation control device according to claim 7, characterized in that, The primary frequency regulation control device is installed in the controller of the wind farm.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it causes the processor to perform the primary frequency regulation control method for a wind farm as described in any one of claims 1 to 6.

10. A primary frequency regulation control device for a wind farm, characterized in that, The primary frequency modulation control device includes: processor; A memory storing a computer program that, when executed by a processor, causes the processor to perform the primary frequency regulation control method for a wind farm as described in any one of claims 1 to 6.

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