A Method and System for Coordinated Active Power and Frequency Control of a Wind Farm and an Energy Storage Power Station

Abstract

The present invention proposes a method and system for coordinated active power and frequency control of a wind farm and an energy storage power station. The coordinated control system of the present invention includes an energy storage power station, a wind farm, an AC / DC hybrid power grid, an electrical load, and a control unit. Through the control of the control unit, the wind power system and the energy storage system are combined to jointly participate in the coordinated active power and frequency control of the system, making up for the problem of insufficient active power of the energy storage power station, providing a very powerful auxiliary system for restoring the system frequency, and effectively improving the active power regulation ability of the system; in the coordinated control method of the present invention, through the energy storage controller, the active power distributor, the energy manager, and the primary frequency control of the wind farm, the active power of the energy storage power station and the increased active power of the wind farm are controlled, and the actual situations of the wind farm and the energy storage power station are combined in real time, effectively and rapidly to provide active power compensation for the frequency drop at the grid connection point, greatly increasing the active power regulation range of the coordinated control system and solving the problem of frequency drop at the grid connection point.

Description

Technical Field

[0001] The present invention belongs to the technical field of energy control, and relates to a method and system for coordinated active frequency control. Background Art

[0002] After large-scale clean energy such as photovoltaic power grids and wind farms is connected to the grid for operation, the random fluctuating output will inevitably affect the balance between the active power output of the system and the load demand. Therefore, when a serious random active power deficit occurs, if the balance between the active power output and the load demand cannot be quickly achieved, the grid frequency will drop significantly, which will cause serious damage to the entire power system.

[0003] Currently, there are various forms for wind farms to participate in primary frequency regulation. For example, measures such as installing energy storage devices in wind farms can be adopted, relying on the energy storage devices to provide support for the grid frequency; frequency regulation can also be achieved by transforming the control system of wind turbines; frequency regulation can also be achieved by adding a frequency regulation function to the power control system of the wind farm. However, relying solely on the active power output of the energy storage power station or the wind farm itself results in a relatively small active power regulation range, and its active power regulation range is very limited. Sometimes it cannot meet the frequency deficit at the grid connection point, and additional auxiliary equipment often needs to be added for active power compensation. Summary of the Invention

[0004] In order to solve the problems described in the background art, the present invention proposes a method and system for coordinated active frequency control of a wind farm and an energy storage power station.

[0005] The coordinated control method of the present invention includes the following steps:

[0006] Step 1: Obtain the remaining available active power P 2’ of the wind farm and the remaining available active power P 3’ of the energy storage power station through real-time monitoring, and simultaneously set the upper limit value P wmax of the remaining available active power of the wind farm and the upper limit value P vmax of the remaining available active power of the energy storage power station;

[0007] Step 2: Compare the remaining available active power P 2’ of the wind farm with its upper limit value P wmax of the remaining available active power, and compare the remaining available active power P 3’ of the energy storage power station with its upper limit value P vmax of the remaining available active power;

[0008] Step 3: If P 2’ ≤P wmax and P 3’ ≤P vmax , then the active power of the wind farm is P2 = P 2’, the remaining active power of the energy storage power station is P3=P 3’ If P 2’ ≤P wmax And P 3’ >P vmax , then the remaining active power of the wind farm is P2=P 2’ , the remaining active power of the energy storage power station is P3=P vmax If P 2’ >P wmax And P 3’ ≤P vmax , then the remaining active power of the wind farm is P2=P wmax , the remaining active power of the energy storage power station is P3=P 3’ If P 2’ >P wmax And P 3’ >P vmax , then the remaining active power of the wind farm is P2=P wmax , the remaining active power of the energy storage power station is P3=P vmax ;

[0009] Step 4: Transmit the active power P2 signal of the wind farm and the active power P3 signal of the energy storage power station to the active power distributor, and transmit the active power shortage P1 signal of the energy manager to the active power distributor;

[0010] Step 5: If SOC>20% and P3≥P1, only the signal of the active power shortage P1 of the energy manager is transmitted to the energy storage controller, and only the energy storage power station provides active compensation; if SOC>20% and P3<P1, then ΔP=P1-P3, the signal of the remaining active power P3 of the energy storage power station is transmitted to the energy storage controller and the ΔP signal is transmitted to the wind turbine controller; if SOC≤20%, then ΔP=P1, the signal of the remaining active power P3 of the energy storage power station is transmitted to the energy storage controller and the ΔP signal is transmitted to the wind turbine controller;

[0011] Step 6: The wind turbine controller receives the ΔP signal and the signal of the remaining available active power P2 of the wind farm, and sets the upper limit value P of the remaining available active power of the wind farm. wmax ;

[0012] Step 7: If ΔP≤P2, set the wind power active power command value P2 * =ΔP+P0, start the primary frequency control of wind power, increase the active power ΔP on the basis of P0, increase the active power to suppress the system frequency drop; if ΔP>P2, set the wind power active power command value P2 * =P wmax +P0, start wind power primary frequency control, add active power P on the basis of P0 wmax, fully generate active power to suppress the system frequency drop; where P0 is the initial power command value of the wind farm (B).

[0013] Further, in the first step, the remaining available active power P of the wind farm 2’ = P w1 +…+ P wn , where P w1 …P wn represents the remaining available active power of each fan connected in parallel in the wind farm.

[0014] Further, in the fourth step, the energy manager collects the grid-connected point frequency signal f sys and the grid-connected point frequency reference value f * sys by a subtractor and subtracts them, then transmits the obtained difference signal to a proportional-integral controller to calculate the active power deficit P1, and finally obtains the signal of the active power deficit P1 through signal processing.

[0015] Even further, in the fan control of the seventh step, a primary frequency modulation controller is used for frequency and power control. Among them, the upper limit clamping controller real-time collects the system frequency amplitude signal. If the system frequency amplitude signal is less than or equal to f min , then the upper limit clamping controller outputs the maximum active power reference signal P * wmax , otherwise, the output is 0; the droop coefficient controller real-time collects the system frequency amplitude signal. If the system frequency amplitude signal is greater than f min and less than f max , then the droop coefficient controller outputs the active power reference signal P * 2, otherwise, the output is 0; the lower limit clamping controller real-time collects the system frequency amplitude signal. If the system frequency amplitude signal is greater than or equal to f max , then the lower limit clamping controller outputs the minimum active power reference signal P * wmin ; finally, the adder receives the output signals of the upper limit clamping controller, the droop coefficient controller, and the lower limit clamping controller, and obtains the active power reference signal of the wind power system through addition calculation; where, f min is the minimum value of the system frequency amplitude signal, f max is the maximum value of the system frequency amplitude signal, P * 2 is the active power command value output by the droop control, P * wmax is the upper limit value of the active power that the wind farm (B) can generate, P * wmin is the lower limit value of the active power that the wind farm (B) can generate.

[0016] The coordinated control system of the present invention includes an energy storage power station, a wind farm, an AC / DC hybrid power grid, and an electricity load. The energy storage power station, the wind farm, the AC / DC hybrid power grid, and the electricity load are all connected to a control unit. The control unit includes an energy storage controller, an active power distributor, and an energy manager. The signal input end of the energy manager is connected to the signal output ends of the energy storage power station, the wind farm, the AC / DC hybrid power grid, the electricity load, and the grid connection point frequency. The signal output end of the energy manager is connected to the signal input end of the active power distributor. The wind farm active power signal and the energy storage power station active power signal are connected to the signal input end of the active power distributor. The signal output end of the active power distributor is connected to the signal input end of the energy storage controller and the control signal input end of the wind farm. The signal input end of the energy storage controller is further connected to the signal output ends of the energy storage power station, the wind farm, the AC / DC hybrid power grid, and the electricity load. The energy storage control signal of the energy storage controller is connected to the control signal input end of the energy storage power station.

[0017] Compared with the prior art, in the coordinated control system of the present invention, through the control of the control unit, the wind power system and the energy storage system are combined to jointly participate in the active power frequency coordination of the system, making up for the problem of insufficient active power of the energy storage power station, providing a very powerful auxiliary system for restoring the system frequency, and effectively improving the active power regulation ability of the system. In the coordinated control method, through the energy storage controller, the active power distributor, the energy manager, and the primary frequency regulation control of the wind farm, the active power of the energy storage power station and the additional active power of the wind farm are controlled. The actual situations of the wind farm and the energy storage power station are combined in real time, effectively and quickly to provide active power compensation for the grid connection point frequency drop, greatly improving the active power regulation range of the coordinated control system and solving the problem of grid connection point frequency drop. Description of the Drawings

[0018] Figure 1 It is a schematic structural diagram of the active power frequency coordinated control system for the wind farm and the energy storage power station.

[0019] Figure 2 It is a schematic principle structure diagram of the energy manager.

[0020] Figure 3 It is a schematic principle structure diagram of the fan primary frequency controller.

[0021] Figure 4 It is a working flowchart of the power monitoring for the wind farm and the energy storage power station.

[0022] Figure 5 It is a working flowchart of the active power distributor.

[0023] Figure 6 It is a working flowchart of the wind power controller.

[0024] Wherein: A - energy storage power station; B - wind farm; C - control unit; D - AC / DC hybrid power grid; E - power consumption load; 1 - energy storage battery; 2 - converter; 3 - AC power grid; 4 - HVDC receiving end; 5 - step-up transformer; 6 - wind turbine generator; 7 - energy storage power station power monitoring signal; 8 - energy storage power station power monitor; 9 - energy storage control signal; 10 - energy storage controller; 11 - wind turbine generator power signal; 12 - active power signal of energy storage power station; 13 - active power signal of distributor No. 1; 14 - active power distributor; 15 - energy manager; 151 - subtractor; 152 - proportional-integral controller; 153 - difference signal; 154 - active power deficit P1; 16 - active power signal of energy manager; 17 - active power signal of wind farm; 18 - active power signal of distributor No. 2; 19 - wind turbine power monitor; 20 - wind turbine controller; 21 - wind turbine generator power monitoring signal; 202 - primary frequency regulation controller; 2021 - system frequency amplitude signal; 2022 - upper limit clamping controller; 2023 - droop coefficient controller; 2024 - lower limit clamping controller; 2025 - output signal of upper limit clamping controller; 2026 - output signal of droop coefficient controller; 2027 - output signal of lower limit clamping controller; 2029 - reference signal of active power of energy storage power station. Detailed implementation manners

[0025] The implementation of the present invention will be described in detail below with reference to the accompanying drawings. However, they do not constitute a limitation to the present invention and are only for illustration purposes. At the same time, through the description, the advantages of the present invention will be more clearly understood. All deformations that can be directly derived or associated by those of ordinary skill in the art from the content disclosed in the present invention shall be considered as the protection scope of the present invention. The positional relationships described in the embodiments are all consistent with those shown in the drawings. Other parts not described in detail in the embodiments are all prior arts.

[0026] 1. Active frequency coordination control system for wind farm and energy storage power station

[0027] The coordination control system is as Figure 1 shown. It is composed of an energy storage power station A, a wind farm B, a control unit C, an AC / DC hybrid power grid D and a power consumption load E. The energy storage power station A, the wind farm B, the AC / DC hybrid power grid D and the power consumption load E are all connected to the control unit C. The control unit C is composed of an energy storage controller 10, an active power distributor 14 and an energy manager 15. The system will be described in detail below.

[0028] Energy storage power station A consists of energy storage battery 1, converter 2, and energy storage power station power monitor 8; energy storage battery 1 is connected to converter 2 and is used to convert direct current into alternating current; energy storage battery 1 is connected to energy storage power station power monitor 8 and is used to transmit the energy storage power station power monitoring signal 7; energy storage power station power monitor 8 is connected to active power distributor 14 and is used to transmit the energy storage power station active power signal 12, and this energy storage power station active power signal 12 is the remaining available active power P3 of energy storage power station A; converter 2 is also connected to the signal input ends of energy storage controller 10 and energy management device 15 through a line, and the control signal input end of converter 2 is connected to energy storage controller 10 and is used to obtain energy storage control signal 9, and this energy storage control signal is the active power signal for the final operation of energy storage power station A, so as to realize the control of the active power for the final operation of energy storage battery 1.

[0029] Wind farm B consists of wind turbines 6, wind turbine power monitors 19, and wind turbine controllers 20; wind turbines 6 consist of multiple groups of parallel-connected wind turbines, and the wind turbines of wind turbines 6 are all connected to wind turbine power monitors 19 and are used to transmit wind turbine power monitoring signals 21; the signal output end of wind turbine power monitor 19 is connected to the signal input end of wind turbine controller 20; the signal output end of wind turbine power monitor 19 is connected to active power distributor 14 and is used to transmit the wind farm active power signal 17, and this wind farm active power signal 17 is the remaining available active power P2 of wind farm B; the signal input end of wind turbine controller 20 is also connected to the signal output end of active power distributor 14, and the signal output end of active power distributor 14 is the output end of distributor No. 2 active power signal 18, and distributor No. 2 active power signal 18 is the ΔP signal; the control signal output end of wind turbine controller 20 is connected to wind turbines 6, so as to realize the control of the active power for the final operation of wind turbines 6.

[0030] The AC / DC hybrid power grid D consists of AC power grid 3, HVDC receiving end 4, and step-up transformer 5; AC power grid 3 and HVDC receiving end 4 are connected in parallel and then connected to step-up transformer 5, and the signal output end of the said step-up transformer 5 is connected to the signal input ends of energy storage controller 10 and energy management device 15.

[0031] In the control unit C, the signal input end of the energy storage controller 10 is connected to the signal output ends of the energy storage power station A, the wind farm B, the AC / DC hybrid power grid D, and the power consumption load E; the signal input end of the energy management unit 15 is connected to the signal output ends of the energy storage power station A, the wind farm B, the AC / DC hybrid power grid D, the power consumption load E, and the signal output end of the grid connection point frequency. The signal output end of the energy management unit 15 is connected to the signal input end of the active power distributor 14. The signal output from the signal output end of the energy management unit 15 is the active power signal 16 of the energy management unit, that is, the signal of the active power deficit P1 of the energy management unit 15. Therefore, the remaining available active power P3 of the energy storage power station A, the remaining available active power P2 of the wind farm B, and the signal of the active power deficit P1 of the energy management unit 15 are input into the active power distributor 14. The distributor No. 1 active power signal 13 of the active power distributor 14 is either the signal of the active power deficit P1 or the active power P3 of the energy storage power station A according to different situations. The distributor No. 1 active power signal 13 is output to the energy storage controller 10, and the energy storage control signal 9 of the energy storage controller 10 is output to the converter 2 of the energy storage power station A; the distributor No. 2 active power signal 18 of the active power distributor 14 is the ΔP signal, and the distributor No. 2 active power signal 18 is output to the fan controller 20.

[0032] As Figure 2 shown, the energy management unit 15 is composed of a series-connected subtractor 151 and a proportional-integral controller 152. The subtractor 151 collects the grid connection point frequency signal f sys and the grid connection point frequency reference value f * sys and transmits the difference signal 153 obtained by taking their difference to the proportional-integral controller 152. The proportional-integral controller 152 is used to calculate the active power deficit P1 154; the active power deficit P1 154 is the active power deficit P1 of the energy management unit 15.

[0033] As Figure 3 shown, the fan controller 20 adopts a primary frequency modulation controller 202. The primary frequency modulation controller 202 is composed of an upper limit clamping controller 2022, a droop coefficient controller 2023, a lower limit clamping controller 2024, and an adder 2028; the upper limit clamping controller 2022, the droop coefficient controller 2023, and the lower limit clamping controller 2024 are arranged in parallel and collect the system frequency amplitude signal 2021 in real time; the adder 2028 is used to receive the output signal 2025 of the upper limit clamping controller, the output signal 2026 of the droop coefficient controller, and the output signal 2027 of the lower limit clamping controller and obtain the wind power system active power reference signal 2029 through addition calculation.

[0034] 2. Active frequency coordinated control method for wind farm and energy storage power station

[0035] The flow chart of the coordinated control method is as Figure 4 、Figure 5 and Figure 6 As shown, a detailed description is given below.

[0036] 2.1 Power Monitoring Workflow of Wind Farm and Energy Storage Power Station

[0037] The power monitoring workflow of the wind farm and the energy storage power station is as Figure 4 shown.

[0038] The remaining available active power P of Wind Farm B is obtained through real-time monitoring 2’ and the remaining available active power P of Energy Storage Power Station A 3’ . At the same time, the upper limit value P of the remaining available active power of Wind Farm B wmax , and the upper limit value P of the remaining available active power of Energy Storage Power Station A vmax are set. Among them, Wind Farm B conducts real-time monitoring through the fan power monitor 19, and the remaining available active power P of Wind Farm B 2’ = P w1 + … + P wn , where P w1 …P wn represents the remaining available active power of each parallel fan in Wind Farm B; Energy Storage Power Station A conducts real-time monitoring through the energy storage power station power monitor 8.

[0039] Compare the remaining available active power P of Wind Farm B 2’ with its upper limit value P of the remaining available active power wmax , and compare the remaining available active power P of Energy Storage Power Station A 3’ with its upper limit value P of the remaining available active power vmax .

[0040] If P 2’ ≤ P wmax and P 3’ ≤ P vmax , then the active power of Wind Farm B is P2 = P 2’ , and the remaining available active power of Energy Storage Power Station A is P3 = P 3’ ; if P 2’ ≤ P wmax and P 3’ > P vmax , then the remaining available active power of Wind Farm B is P2 = P 2’ , and the remaining available active power of Energy Storage Power Station A is P3 = P vmax ; if P 2’ > P wmax and P 3’ ≤ P vmax , then the remaining available active power of Wind Farm B is P2 = P wmax , and the remaining available active power of Energy Storage Power Station A is P3 = P3’ ; If P 2’ > P wmax and P 3’ > P vmax , then the remaining available active power of wind farm B is P2 = P wmax , and the remaining available active power of energy storage power station A is P3 = P vmax .

[0041] The remaining available active power P2 of the above-mentioned wind farm B is the active power signal 17 of the wind farm, and the remaining available active power P3 of the energy storage power station A is the active power signal 12 of the energy storage power station.

[0042] The signal of the remaining available active power P2 of wind farm B and the signal of the remaining available active power P3 of energy storage power station A are fed to the active power distributor 14.

[0043] 2.2 Working process of the active power distributor

[0044] The working process of the active power distributor 14 is as Figure 5 shown.

[0045] The signal of the active power deficit P1 of the energy manager 15 is also transmitted to the active power distributor 14. Among them, the energy manager 15 collects the grid connection point frequency signal f sys and the grid connection point frequency reference value f * sys through the subtractor 151, subtracts them, then transmits the obtained difference signal 153 to the proportional-integral controller 152, calculates the active power deficit P1154, and finally obtains the signal of the active power deficit P1 through signal processing.

[0046] In the active power distributor 14, if SOC > 20% and P3 ≥ P1, only the signal of the active power P1 of the energy manager 15 is transmitted to the energy storage controller 10, and only the energy storage power station A provides active power compensation; if SOC > 20% and P3 < P1, then ΔP = P1 - P3, the signal of the remaining available active power P3 of the energy storage power station A is transmitted to the energy storage controller 10 and the ΔP signal is transmitted to the wind turbine controller 20; if SOC ≤ 20%, then ΔP = P1, the signal of the remaining available active power P3 of the energy storage power station A is transmitted to the energy storage controller 10 and the ΔP signal is transmitted to the wind turbine controller 20.

[0047] 2.3 Working process of the wind power controller

[0048] The working process of the wind power controller 20 is as Figure 6 shown.

[0049] The wind turbine controller 20 receives the ΔP signal and the signal of the remaining available active power P2 of wind farm B, and sets the upper limit value P of the remaining available active power of wind farm B. wmax .

[0050] The wind turbine controller 20 is used to change the active power output through primary frequency modulation control according to the actual situation. If ΔP≤P2, the wind power active power command value P2 is set * =ΔP+P0, start the primary frequency control of wind power, increase the active power ΔP on the basis of P0, increase the active power to suppress the system frequency drop; if ΔP>P2, set the wind power active power command value P2 * =P wmax +P0, start wind power primary frequency control, add active power P on the basis of P0 wmax , full active power is generated to suppress the system frequency drop; where P0 is the initial power command value of wind farm B.

[0051] Increased active power: the required additional power has not reached the upper limit of the power that can be generated, so only some power needs to be increased; Full active power: the required additional power has reached the upper limit of the power that can be generated, so the wind turbine needs to generate full power, that is, generate all the power it can.

[0052] The fan control 20 uses a primary frequency modulation controller 202 for control, wherein the upper limit clamp controller 2022 collects the system frequency amplitude signal 2021 in real time. If the system frequency amplitude signal 2021 is less than or equal to f min , the upper limit clamp controller 2022 outputs the maximum active power reference signal P * wmax , otherwise, the output is 0; the droop coefficient controller 2023 collects the system frequency amplitude signal 2021 in real time, if the system frequency amplitude signal 2021 is greater than f min and less than f max , then the droop coefficient controller 2023 outputs an active power reference signal P * 2, otherwise, the output is 0; the lower limit clamp controller 2024 collects the system frequency amplitude signal 2021 in real time, if the system frequency amplitude signal 2021 is greater than or equal to f max , then the lower limit clamp controller 2024 outputs the minimum active power reference signal P * wmin ; Finally, the adder 2028 receives the upper limit clamp controller output signal 2025, the droop coefficient controller output signal 2026 and the lower limit clamp controller output signal 2027, and obtains the wind power system active power reference signal 2029 through addition calculation; wherein, f min is the minimum value of the system frequency amplitude signal, f max is the maximum value of the system frequency amplitude signal, P *2 is the active power command value for droop control output, P * wmax is the upper limit of the active power that wind farm B can generate, P * wmin is the lower limit of the active power that wind farm B can generate.

[0053] The preferred embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings and specific embodiments. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, and these simple modifications all fall within the protection scope of the present invention.

Claims

1. A method for coordinated active power and frequency control of a wind farm and an energy storage power station, characterized in that Including the following steps: Step 1: Obtain the remaining available active power P of the wind farm (B) through real-time monitoring 2’ and the remaining available active power P of the energy storage power station (A) 3’ . At the same time, set the upper limit value P of the remaining available active power of the wind farm (B) wmax , the upper limit value P of the remaining available active power of the energy storage power station (A) vmax ; Step 2: Compare the remaining available active power P of the wind farm (B) 2’ with its upper limit value P of the remaining available active power wmax and compare the remaining available active power P of the energy storage power station (A) 3’ with its upper limit value P of the remaining available active power vmax ; Step 3. If P 2’ ≤P wmax and P 3’ ≤P vmax , then the remaining available active power of wind farm (B) is P2 = P 2’ , and the remaining available active power of energy storage power station (A) is P3 = P 3’ ; if P 2’ ≤P wmax and P 3’ >P vmax , then the remaining available active power of wind farm (B) is P2 = P 2’ , and the remaining available active power of energy storage power station (A) is P3 = P vmax ; if P2 > P wmax and P 3’ ≤P vmax , then the remaining available active power of wind farm (B) is P2 = P wmax , and the remaining available active power of energy storage power station (A) is P3 = P 3’ ; if P 2’ >P wmax and P 3’ >P vmax , then the remaining available active power of wind farm (B) is P2 = P wmax , and the remaining available active power of energy storage power station (A) is P3 = P vmax ; Step 4: Transmit the signal of the remaining available active power P2 of the wind farm (B) and the signal of the remaining available active power P3 of the energy storage power station (A) to the active power distributor (14), and at the same time transmit the signal of the active power deficit P1 of the energy manager (15) to the active power distributor (14); Step 5: If SOC > 20% and P3 ≥ P1, only transmit the signal of the active power deficit P1 of the energy manager (15) to the energy storage controller (10), and only the energy storage power station (A) provides active power compensation; if SOC > 20% and P3 < P1, then ΔP = P1 - P3, transmit the signal of the remaining available active power P3 of the energy storage power station (A) to the energy storage controller (10) and transmit the ΔP signal to the wind turbine controller (20); if SOC ≤ 20%, then ΔP = P1, transmit the signal of the remaining available active power P3 of the energy storage power station (A) to the energy storage controller (10) and transmit the ΔP signal to the wind turbine controller (20); Step 6: The fan controller (20) receives the ΔP signal and the signal of the remaining available active power P2 of the wind farm (B), and sets the upper limit value P of the remaining available active power of the wind farm (B). wmax ; Step 7: If ΔP ≤ P2, set the wind power active power command value to P2 * = ΔP + P0, start the primary frequency regulation control of the wind power, increase the active power by ΔP on the basis of P0, and increase the active power to suppress the system frequency drop; if ΔP > P2, set the wind power active power command value to P2 * = P wmax + P0, start the primary frequency regulation control of the wind power, increase the active power by P on the basis of P0 wmax , and fully generate active power to suppress the system frequency drop; where P0 is the initial power command value of the wind farm (B).

2. The active frequency coordinated control method for a wind farm and an energy storage power station according to claim 1, wherein: In the first step, the remaining available active power P of the wind farm (B) 2’ = P w1 +…+ P wn , where P w1 …P wn represents the remaining available active power of each fan connected in parallel in the wind farm (B).

3. A coordinated active power and frequency control method for a wind farm and an energy storage power station according to claim 1, characterized in that: In the fourth step, the energy manager (15) collects the grid connection point frequency signal f sys and the grid connection point frequency reference value f * sys through a subtractor (151), subtracts them, then transmits the obtained difference signal (153) to a proportional-integral controller (152) to calculate the active power deficit P1 (154), and finally obtains the signal of the active power deficit P1 through signal processing.

4. A method for coordinated active power and frequency control of a wind farm and an energy storage power station according to claim 3, characterized in that: In the fan controller (20) of step seven, a primary frequency modulation controller (202) is used for frequency and power control. Among them, the upper limit clamping controller (2022) collects the system frequency amplitude signal (2021) in real time. If the system frequency amplitude signal (2021) is less than or equal to f min , then the upper limit clamping controller (2022) outputs the maximum active power reference signal P * wmax . Otherwise, the output is 0. The droop coefficient controller (2023) collects the system frequency amplitude signal (2021) in real time. If the system frequency amplitude signal (2021) is greater than f min and less than f max , then the droop coefficient controller (2023) outputs the active power reference signal P * 2. Otherwise, the output is 0. The lower limit clamping controller (2024) collects the system frequency amplitude signal (2021) in real time. If the system frequency amplitude signal (2021) is greater than or equal to f max , then the lower limit clamping controller (2024) outputs the minimum active power reference signal P * wmin ; Finally, the adder (2028) receives the output signal (2025) of the upper limit clamping controller, the output signal (2026) of the droop coefficient controller, and the output signal (2027) of the lower limit clamping controller, and obtains the active power reference signal (2029) of the wind power system through addition calculation; where f min is the minimum value of the system frequency amplitude signal, f max is the maximum value of the system frequency amplitude signal, P * 2 is the active power command value output by the droop control, P * wmax is the upper limit value of the active power that the wind farm (B) can generate, P * wmin is the lower limit value of the active power that the wind farm (B) can generate.

5. A system for the active frequency coordinated control method of a wind farm and an energy storage power station according to any one of claims 1-4, comprising an energy storage power station (A), a wind farm (B), an AC / DC hybrid power grid (D), and an electrical load (E), characterized in that: The energy storage power station (A), the wind farm (B), the AC / DC hybrid power grid (D) and the electrical load (E) are all connected to the control unit (C); The control unit (C) includes an energy storage controller (10), an active power distributor (14) and an energy manager (15); the signal input end of the energy manager (15) is connected to the signal output ends of the energy storage power station (A), the wind farm (B), the AC / DC hybrid power grid (D), the electrical load (E) and the grid connection point frequency, and the signal output end of the energy manager (15) is connected to the signal input end of the active power distributor (14); the wind farm active power signal (17) of the wind farm (B) and the energy storage power station active power signal (12) of the energy storage power station (A) are connected to the signal input end of the active power distributor (14); the signal output end of the active power distributor (14) is connected to the signal input end of the energy storage controller (10) and the control signal input end of the wind farm (B); the signal input end of the energy storage controller (10) is further connected to the signal output ends of the energy storage power station (A), the wind farm (B), the AC / DC hybrid power grid (D) and the electrical load (E), and the energy storage control signal (9) of the energy storage controller (10) is connected to the control signal input end of the energy storage power station (A).

6. The active frequency coordinated control system for a wind farm and an energy storage power station according to claim 5, wherein: The energy storage power station (A) includes an energy storage battery (1), a converter (2) and an energy storage power station power monitor (8); the energy storage battery (1) is connected to the converter (2) for converting direct current into alternating current, the energy storage battery (1) is connected to the energy storage power station power monitor (8) for transmitting the energy storage power station power monitoring signal (7); the energy storage power station power monitor (8) is connected to the active power distributor (14) for transmitting the energy storage power station active power signal (12); the converter (2) is connected to the signal input ends of the energy storage controller (10) and the energy manager (15) through a line, and the control signal input end of the converter (2) is connected to the energy storage controller (10) for obtaining the energy storage control signal (9).

7. A coordinated active power - frequency control system for a wind farm and an energy storage power station according to claim 5 or 6, characterized in that: The wind farm (B) includes wind turbines (6), a wind turbine power monitor (19), and a wind turbine controller (20); the wind turbines (6) consist of multiple groups of parallel-connected wind turbines, and the wind turbines of the wind turbine group (6) are all connected to the wind turbine power monitor (19) for transmitting the wind turbine group power monitoring signal (21); the signal output end of the wind turbine power monitor (19) is connected to the signal input end of the wind turbine controller (20), and the signal output end of the wind turbine power monitor (19) is connected to the active power distributor (14) for transmitting the wind farm active power signal (17); the signal input end of the wind turbine controller (20) is also connected to the signal output end of the active power distributor (14), and the control signal output end of the wind turbine controller (20) is connected to the wind turbines (6).

8. A coordinated active power and frequency control system for a wind farm and an energy storage power station according to claim 7, characterized in that: The AC / DC hybrid power grid (D) includes an AC power grid (3), an HVDC receiving end (4), and a step-up transformer (5); the AC power grid (3) and the HVDC receiving end (4) are connected in parallel and then connected to the step-up transformer (5), and the signal output end of the step-up transformer (5) is connected to the signal input ends of the energy storage controller (10) and the energy manager (15).

9. A coordinated active power and frequency control system for a wind farm and an energy storage power station according to claim 5 or 8, characterized in that: The energy manager (15) includes a subtractor (151) and a proportional-integral controller (152) connected in series; the subtractor (151) collects the grid connection point frequency signal f sys and the grid connection point frequency reference value f * sys and transmits the difference signal (153) obtained by taking the difference between them to the proportional-integral controller (152), and the proportional-integral controller (152) is used to calculate the active power deficit P1 (154).

10. A coordinated active power and frequency control system for a wind farm and an energy storage power station according to claim 7, characterized in that: The wind turbine controller (20) adopts a primary frequency modulation controller (202), and the primary frequency modulation controller (202) includes an upper limit clamping controller (2022), a droop coefficient controller (2023), a lower limit clamping controller (2024), and an adder (2028); the upper limit clamping controller (2022), the droop coefficient controller (2023), and the lower limit clamping controller (2024) are arranged in parallel for real-time acquisition of the system frequency amplitude signal (2021); the adder (2028) is used to receive the upper limit clamping controller output signal (2025), the droop coefficient controller output signal (2026), and the lower limit clamping controller output signal (2027) and obtain the wind power system active power reference signal (2029) through addition calculation.

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