Power control method and device for fan and hybrid energy storage system

Abstract

The application discloses a power control method and device for a fan and a hybrid energy storage system, and the method comprises the following steps: acquiring fan power output by the fan, acquiring inertia response of the hybrid energy storage system and active power required for primary frequency modulation; determining response power of a lithium battery energy storage unit and response power of a flywheel energy storage unit; dividing energy storage areas of the lithium battery energy storage unit and the flywheel energy storage unit according to the lithium battery energy storage unit battery state of charge percentage and the flywheel energy storage unit battery state of charge percentage, and obtaining corresponding multiple energy storage areas; distributing output of the lithium battery energy storage unit and the flywheel energy storage unit; and cooperatively controlling the response power of the lithium battery energy storage unit and the response power of the flywheel energy storage unit. The application can realize reasonable distribution of output of the fan and the hybrid energy storage system, reduce fluctuation risk of power grid frequency, and ensure stability of the power grid.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power system frequency control, in particular to a power control method and device for a wind turbine and a hybrid energy storage system. BACKGROUND

[0002] This section is intended to provide background or context to the embodiments of the application recited in the claims. The description herein does not constitute admission that the prior art is prior art nor does it constitute an admission of any description in this section as prior art to an application described herein and infringed thereby.

[0003] With the development of science and technology, the field of power system control is committed to building a new type of power system that meets the needs of the new era. Wind power has become an important force in this transition process due to its unique advantages of being clean, environmentally friendly, and emission-free. In the prior art, the significant randomness and volatility of wind power have resulted in the inability of the power system to operate safely and stably. Currently, the method of coordinated control of power for wind turbines and hybrid energy storage systems cannot reasonably allocate the output of wind turbines and hybrid energy storage systems, resulting in an increased risk of fluctuations in power grid frequency and affecting the stability of the power grid. SUMMARY

[0004] The embodiments of the present application provide a power control method for a wind turbine and a hybrid energy storage system to reasonably allocate the output of the wind turbine and the hybrid energy storage system, reduce the risk of fluctuations in the power grid frequency, and ensure the stability of the power grid. The hybrid energy storage system includes a lithium battery energy storage unit and a flywheel energy storage unit. The method comprises:

[0005] Obtaining wind turbine power output by a wind turbine, and obtaining inertia response and active power required for primary frequency modulation of a hybrid energy storage system;

[0006] When the power grid frequency at the power station grid connection point is within the frequency modulation dead zone, the wind turbine power is decomposed to obtain a low-frequency component and a high-frequency component of the wind turbine power. The low-frequency component is determined as the wind turbine grid connection power, and the high-frequency component is determined as the fluctuation suppression power of the hybrid energy storage system. The fluctuation suppression power is further decomposed, and the low-frequency component obtained after the further decomposition is determined as the response power of the lithium battery energy storage unit, and the high-frequency component obtained after the further decomposition is determined as the response power of the flywheel energy storage unit. When the power grid frequency at the power station grid connection point is outside the frequency modulation dead zone, the inertia response and the active power required for primary frequency modulation are decomposed to obtain a low-frequency component and a high-frequency component of the hybrid energy storage system. The low-frequency component of the hybrid energy storage system is determined as the response power of the lithium battery energy storage unit, and the high-frequency component of the hybrid energy storage system is determined as the response power of the flywheel energy storage unit.

[0007] Obtain the lithium battery energy storage unit battery state of charge percentage and the flywheel energy storage unit battery state of charge percentage, and divide the lithium battery energy storage unit and the flywheel energy storage unit into energy storage regions according to the lithium battery energy storage unit battery state of charge percentage and the flywheel energy storage unit battery state of charge percentage, to obtain corresponding multiple energy storage regions.

[0008] According to the size relationship between the lithium battery energy storage unit battery state of charge percentage and the flywheel energy storage unit battery state of charge percentage in each energy storage region, the output of the lithium battery energy storage unit and the flywheel energy storage unit is allocated, and the response power of the lithium battery energy storage unit and the response power of the flywheel energy storage unit are cooperatively controlled after the output allocation.

[0009] The embodiment of the present application also provides a power control device of a fan and a hybrid energy storage system, to reasonably allocate the output of the fan and the hybrid energy storage system, reduce the fluctuation risk of the power grid frequency, and ensure the stability of the power grid, wherein the hybrid energy storage system comprises a lithium battery energy storage unit and a flywheel energy storage unit, and the device comprises:

[0010] A power acquisition module is configured to acquire the fan power output by the fan and the inertia response and the active power required for primary frequency modulation of the hybrid energy storage system.

[0011] A response power determination module is configured to, when the power grid frequency at the power station grid connection point is within the frequency modulation dead zone, decompose the fan power to obtain a low-frequency component and a high-frequency component of the fan power, determine the low-frequency component as the fan grid connection power, determine the high-frequency component as the fluctuation suppression power of the hybrid energy storage system, re-decompose the fluctuation suppression power, determine the low-frequency component obtained after the re-decomposition as the response power of the lithium battery energy storage unit, and determine the high-frequency component obtained after the re-decomposition as the response power of the flywheel energy storage unit; and when the power grid frequency at the power station grid connection point is outside the frequency modulation dead zone, decompose the inertia response and the active power required for primary frequency modulation to obtain a low-frequency component and a high-frequency component of the hybrid energy storage system, determine the low-frequency component of the hybrid energy storage system as the response power of the lithium battery energy storage unit, and determine the high-frequency component of the hybrid energy storage system as the response power of the flywheel energy storage unit.

[0012] An energy storage region division module is configured to obtain the lithium battery energy storage unit battery state of charge percentage and the flywheel energy storage unit battery state of charge percentage, and divide the lithium battery energy storage unit and the flywheel energy storage unit into energy storage regions according to the lithium battery energy storage unit battery state of charge percentage and the flywheel energy storage unit battery state of charge percentage, to obtain corresponding multiple energy storage regions.

[0013] The response power cooperative control module is used for distributing the output of the lithium battery energy storage unit and the flywheel energy storage unit according to the size relationship between the lithium battery energy storage unit state of charge percentage and the flywheel energy storage unit state of charge percentage in each energy storage area; and after the output distribution, the response power of the lithium battery energy storage unit and the response power of the flywheel energy storage unit are cooperatively controlled.

[0014] The embodiment of the present application further provides a computer device, which comprises a memory, a processor and a computer program stored in the memory and capable of running on the processor, and the processor implements the power control method of the fan and the hybrid energy storage system when executing the computer program.

[0015] The embodiment of the present application further provides a computer readable storage medium, which stores a computer program, and the computer program implements the power control method of the fan and the hybrid energy storage system when executed by a processor.

[0016] The embodiment of the present application further provides a computer program product, which comprises a computer program, and the computer program implements the power control method of the fan and the hybrid energy storage system when executed by a processor.

[0017] In the embodiment of the present application, the fan power output by the fan is obtained, the inertia response of the hybrid energy storage system and the active power required for primary frequency modulation are obtained, when the power grid frequency at the power station grid connection point is within the frequency modulation dead zone, the fan power is decomposed to obtain the low-frequency component and the high-frequency component of the fan power, the low-frequency component is determined as the fan grid connection power, and the high-frequency component is determined as the fluctuation suppression power of the hybrid energy storage system, the fluctuation suppression power is decomposed again, and the low-frequency component obtained after the decomposition is determined as the response power of the lithium battery energy storage unit, and the high-frequency component obtained after the decomposition is determined as the response power of the flywheel energy storage unit; when the power grid frequency at the power station grid connection point is outside the frequency modulation dead zone, the inertia response and the active power required for primary frequency modulation are decomposed to obtain the low-frequency component and the high-frequency component of the hybrid energy storage system, the low-frequency component of the hybrid energy storage system is determined as the response power of the lithium battery energy storage unit, and the high-frequency component of the hybrid energy storage system is determined as the response power of the flywheel energy storage unit; the percentage of the state of charge of the lithium battery energy storage unit and the percentage of the state of charge of the flywheel energy storage unit are obtained, the lithium battery energy storage unit and the flywheel energy storage unit are respectively divided into energy storage regions according to the percentage of the state of charge of the lithium battery energy storage unit and the percentage of the state of charge of the flywheel energy storage unit, and a plurality of corresponding energy storage regions are obtained; the output of the lithium battery energy storage unit and the flywheel energy storage unit is distributed according to the size relationship between the percentage of the state of charge of the lithium battery energy storage unit and the percentage of the state of charge of the flywheel energy storage unit in each energy storage region; and the response power of the lithium battery energy storage unit and the response power of the flywheel energy storage unit are cooperatively controlled after the output distribution. In the above process, based on the fan power and the inertia response of the hybrid energy storage system and the active power required for primary frequency modulation, the response power of the lithium battery energy storage unit and the response power of the flywheel energy storage unit are determined, and then the hybrid energy storage mode of the flywheel energy storage unit plus the lithium battery energy storage unit is used for cooperative control of the response power. Thus, the reasonable distribution of the output of the fan and the hybrid energy storage system is realized, the fluctuation risk of the power grid frequency is reduced, and the stability of the power grid is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort based on these drawings. In the drawings:

[0019] Figure 1 The flow chart of the power control method of the fan and the hybrid energy storage system in the embodiment of the present application;

[0020] Figure 2 The flow chart of the fan power decomposition in the embodiment of the present application;

[0021] Figure 3 SOC partitioning diagram for the energy storage unit in the embodiment of the present application;

[0022] Figure 4 Maximum charge and discharge power curve of the energy storage unit in the embodiment of the present application;

[0023] Figure 5 Schematic diagram of the power control device of the wind turbine and the hybrid energy storage system in the embodiment of the present application. DETAILED DESCRIPTION

[0024] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the embodiments of the present application are further described in detail below with reference to the drawings. Herein, the illustrative embodiments of the present application and the descriptions thereof are used to explain the present application but not to limit the present application.

[0025] Figure 1 Flow chart of the power control method of the wind turbine and the hybrid energy storage system in the embodiment of the present application, the hybrid energy storage system comprising a lithium battery energy storage unit and a flywheel energy storage unit, the method comprising:

[0026] Step 101, obtaining the wind turbine power output by the wind turbine, and obtaining the inertia response and the active power required for primary frequency modulation of the hybrid energy storage system;

[0027] Step 102, when the power grid frequency at the power station grid connection point is within the frequency modulation dead zone, decomposing the wind turbine power to obtain a low-frequency component and a high-frequency component of the wind turbine power, determining the low-frequency component as the wind turbine grid connection power, determining the high-frequency component as the fluctuation damping power of the hybrid energy storage system, re-decomposing the fluctuation damping power, determining the low-frequency component obtained after the re-decomposition as the response power of the lithium battery energy storage unit, and determining the high-frequency component obtained after the re-decomposition as the response power of the flywheel energy storage unit; when the power grid frequency at the power station grid connection point is outside the frequency modulation dead zone, decomposing the inertia response and the active power required for primary frequency modulation to obtain a low-frequency component and a high-frequency component of the hybrid energy storage system, determining the low-frequency component of the hybrid energy storage system as the response power of the lithium battery energy storage unit, and determining the high-frequency component of the hybrid energy storage system as the response power of the flywheel energy storage unit;

[0028] Step 103, obtaining the lithium battery energy storage unit battery state of charge percentage and the flywheel energy storage unit battery state of charge percentage, and dividing the energy storage region of the lithium battery energy storage unit and the flywheel energy storage unit according to the lithium battery energy storage unit battery state of charge percentage and the flywheel energy storage unit battery state of charge percentage, respectively, to obtain a plurality of corresponding energy storage regions;

[0029] In step 104, the output of the lithium battery energy storage unit and the flywheel energy storage unit is allocated according to the size relationship between the state of charge percentage of the lithium battery energy storage unit and the state of charge percentage of the flywheel energy storage unit in each energy storage area; after the output is allocated, the response power of the lithium battery energy storage unit and the response power of the flywheel energy storage unit are cooperatively controlled.

[0030] The following describes each step.

[0031] In step 101, the fan power output by the fan is obtained, and the inertia response of the hybrid energy storage system and the active power required for primary frequency modulation are obtained.

[0032] In specific embodiments, the fan parameters and the wind speed are obtained, the fan power curve is determined according to the fan parameters and the wind speed, and the fan power output by the fan is obtained. Outside the frequency modulation dead zone, the power of the hybrid energy storage system is composed of two parts, one part is the power of the inertia response and the primary frequency modulation response, and the other part is the difference between the fan power at the frequency modulation starting time and the actual fan power within the frequency modulation period. Further, when there is a second-level power prediction in the wind farm, outside the frequency modulation dead zone, the energy storage power is composed of two parts, one part is the difference between the frequency modulation power and the predicted increase in fan power, and the other part is the difference between the fan power at the frequency modulation starting time and the actual fan power within the frequency modulation period.

[0033] In step 102, when the power grid frequency at the power station grid connection point is within the frequency modulation dead zone, the fan power is decomposed to obtain the low-frequency component and the high-frequency component of the fan power, the low-frequency component is determined as the fan grid connection power, and the high-frequency component is determined as the fluctuation suppression power of the hybrid energy storage system. The fluctuation suppression power is further decomposed, and the low-frequency component obtained after the further decomposition is determined as the response power of the lithium battery energy storage unit, and the high-frequency component obtained after the further decomposition is determined as the response power of the flywheel energy storage unit. When the power grid frequency at the power station grid connection point is outside the frequency modulation dead zone, the active power required for inertia response and primary frequency modulation is decomposed to obtain the low-frequency component and the high-frequency component of the hybrid energy storage system, the low-frequency component of the hybrid energy storage system is determined as the response power of the lithium battery energy storage unit, and the high-frequency component of the hybrid energy storage system is determined as the response power of the flywheel energy storage unit.

[0034] In specific embodiments, the complete ensemble empirical mode decomposition method is used to smooth the fan power, and the real-time power of the wind turbine generator set is decomposed, and the number of decomposition layers is automatically determined: when the low-frequency component meets the wind power grid connection power fluctuation standard, the decomposition cycle is stopped, and the high-frequency component of the wind power output is the fluctuation suppression power of the hybrid energy storage; the fluctuation suppression power of the hybrid energy storage is further decomposed, and the criterion for the number of decomposition layers is that the residual signal in the complete ensemble empirical mode decomposition method is a monotonic signal at the kth decomposition, and the cycle is stopped and the decomposition is ended.

[0035] Figure 2 A flow chart for fan power decomposition in embodiments of the present application is shown in FIG. 1, in an embodiment, the fluctuation power is re-decomposed, and the low-frequency component obtained after re-decomposition is determined as the response power of the lithium battery energy storage unit, and the high-frequency component obtained after re-decomposition is determined as the response power of the flywheel energy storage unit, including: Figure 2

[0036] Step 201, using the ICEEMDAN complete ensemble empirical mode decomposition method to perform cyclic decomposition on the fluctuation power, updating the residual signal in the complete ensemble empirical mode decomposition method after decomposition, until the residual signal is a monotonic signal, stop the cycle, get the fluctuation power after cyclic decomposition;

[0037] Step 202, according to the preset condition, determine the low-frequency component obtained after re-decomposition and the high-frequency component obtained after re-decomposition from the fluctuation power after cyclic decomposition, determine the low-frequency component obtained after re-decomposition as the response power of the lithium battery energy storage unit, and determine the high-frequency component obtained after re-decomposition as the response power of the flywheel energy storage unit.

[0038] In specific embodiments, the preset condition includes selecting a frequency division parameter d (d = 1, 2,..., n-1), n is the number of cycles; reconstructing the fluctuation power after cyclic decomposition to obtain high-frequency components and low-frequency components. In step 103, the lithium battery energy storage unit battery state of charge percentage and the flywheel energy storage unit battery state of charge percentage are obtained, and the lithium battery energy storage unit and the flywheel energy storage unit are respectively divided into energy storage regions according to the lithium battery energy storage unit battery state of charge percentage and the flywheel energy storage unit battery state of charge percentage, to obtain a plurality of corresponding energy storage regions.

[0039] In an embodiment, the lithium battery energy storage unit and the flywheel energy storage unit are respectively divided into energy storage regions according to the lithium battery energy storage unit battery state of charge percentage and the flywheel energy storage unit battery state of charge percentage, to obtain a plurality of corresponding energy storage regions, including:

[0040] For the lithium battery energy storage unit, the energy storage region with the lithium battery energy storage unit battery state of charge percentage in the range of [0, 0.2) is determined as the over-discharge region; the energy storage region with the lithium battery energy storage unit battery state of charge percentage in the range of [0.2, 0.3) is determined as the deep charge region; the energy storage region with the lithium battery energy storage unit battery state of charge percentage in the range of [0.3, 0.7) is determined as the shallow charge and shallow discharge region; the energy storage region with the lithium battery energy storage unit battery state of charge percentage in the range of [0.7, 0.8) is determined as the deep discharge region; the energy storage region with the lithium battery energy storage unit battery state of charge percentage in the range of [0.8, 1.0] is determined as the overcharge region;

[0041] ​For the flywheel energy storage unit, the energy storage region with the flywheel energy storage unit battery state of charge percentage in the range of [0~0.1) is determined as the over-discharge region; the energy storage region with the flywheel energy storage unit battery state of charge percentage in the range of [0.1~0.4) is determined as the deep charge region; the energy storage region with the flywheel energy storage unit battery state of charge percentage in the range of [0.4~0.6) is determined as the shallow charge and discharge region; the energy storage region with the flywheel energy storage unit battery state of charge percentage in the range of [0.6~0.9) is determined as the deep discharge region; and the energy storage region with the flywheel energy storage unit battery state of charge percentage in the range of [0.9~1.0] is determined as the over-charge region.

[0042] In specific embodiments, the battery state of charge (SOC) of the hybrid energy storage system is divided into regions, Figure 3 The SOC partition diagram of the energy storage unit in the embodiments of the present application is shown in FIG. 1. Figure 3 As shown, the SOC of the flywheel energy storage unit and the SOC of the lithium battery energy storage unit are divided into five regions. When the SOC of the flywheel energy storage unit and the SOC of the lithium battery energy storage unit enter the over-charge and discharge region, in order to avoid the over-charge and discharge loss and affect the service life of the hybrid energy storage system, a Sigmoid function is used to limit the charge and discharge power of the energy storage system, Figure 4 The maximum charge and discharge power curve of the energy storage unit in the embodiments of the present application is shown in FIG. 2. Figure 4 The flywheel discharge / charge represents the flywheel energy storage unit discharge / charge; the battery discharge / charge represents the lithium battery energy storage unit discharge / charge. The maximum charge and discharge power is expressed as:

[0043]

[0044] In the formula, Pmax, flywheel and Pmax, battery are the maximum charge power of the flywheel energy storage unit and the maximum charge power of the lithium battery energy storage unit, respectively; Pmax, flywheel and Pmax, battery are the maximum discharge power of the flywheel energy storage unit and the maximum discharge power of the lithium battery energy storage unit, respectively; Pmax, battery is the maximum allowable discharge power of the lithium battery energy storage unit; and F Pmax, battery is the maximum allowable discharge power of the lithium battery energy storage unit; and L SOCflywheel and SOCbattery are the battery state of charge of the flywheel energy storage unit and the battery state of charge of the lithium battery energy storage unit, respectively; SOCbattery (t) is the battery state of charge of the lithium battery energy storage unit at time t; SOCmin, battery is the minimum battery state of charge of the lithium battery energy storage unit; SOCmax, battery is the maximum battery state of charge of the lithium battery energy storage unit; and u is an adjustment adaptive parameter, which is a positive number.

[0045] The charge and discharge control of the hybrid energy storage system is not only limited by the maximum charge and discharge power, but also should fully play its role in fluctuation smoothing and frequency regulation under the premise of guaranteeing its performance. As shown in Table 1, it is an SOC partition table of the hybrid energy storage system in normal working condition. SOC F is the SOC of the flywheel energy storage unit. L is the SOC of the lithium battery energy storage unit.

[0046] Table 1: SOC partition of the hybrid energy storage system in normal working condition

[0047]

[0048] a. In the S4, S7, S8 region, SOC F > SOC L When charging, the lithium battery energy storage unit is preferentially charged, so that the SOC L returns to the shallow charging and discharging region, and the remaining power is used to charge the flywheel energy storage unit. When discharging, the flywheel energy storage unit is preferentially discharged, and the lithium battery energy storage unit is used to supplement the discharge when insufficient. The energy storage is defined as positive, and at this time the charge and discharge power of the hybrid energy storage system is:

[0049]

[0050] In the formula, and are the charging power / discharging power of the flywheel energy storage unit and the lithium battery energy storage unit at time t respectively; are the maximum allowable discharging power of the flywheel energy storage unit and the maximum allowable charging power of the lithium battery energy storage unit at time t respectively; is the demand power instruction at time t; P h,t , P l,t are the high-frequency power and low-frequency power after decomposition of the power instruction at time t respectively.

[0051] b. In the S2, S3, S6 region, SOC F < SOC L When charging, the flywheel energy storage unit is preferentially charged, so that the SOC F returns to the shallow charging and discharging region, and the remaining power is used to charge the lithium battery energy storage unit. Similarly, when discharging, the lithium battery energy storage unit is preferentially discharged, and the flywheel energy storage unit is used to supplement the discharge when insufficient.

[0052]

[0053] c. In the S5 region, both are in the shallow charging and discharging region. The flywheel energy storage unit uses high-frequency demand to preferentially charge and discharge, and the lithium battery energy storage unit uses low-frequency demand to supplement.

[0054]

[0055] d. S1, S9 region, both are in deep charge and discharge area. Lithium battery energy storage unit uses low frequency demand priority charge and discharge, flywheel energy storage unit uses high frequency demand to supplement.

[0056]

[0057] If the lithium battery energy storage unit and the flywheel energy storage unit are overcharged and discharged, the following operations are performed:

[0058] a. Only the flywheel energy storage unit is in the overcharge and discharge area:

[0059] overcharge:

[0060] over-discharge:

[0061] b. Only the lithium battery energy storage unit is in the overcharge and discharge area:

[0062] overcharge:

[0063] over-discharge:

[0064] c. Flywheel energy storage unit and lithium battery energy storage unit are in overcharge and discharge area:

[0065] overcharge:

[0066] over-discharge:

[0067] d. Flywheel energy storage unit and lithium battery energy storage unit are in overcharge and discharge opposite area:

[0068] flywheel overcharge:

[0069] flywheel over-discharge:

[0070] In an embodiment, according to the size relationship between the lithium battery energy storage unit battery state of charge percentage and the flywheel energy storage unit battery state of charge percentage in each energy storage area, the output of the lithium battery energy storage unit and the flywheel energy storage unit is allocated; after the output allocation, the response power of the lithium battery energy storage unit and the response power of the flywheel energy storage unit are cooperatively controlled, including:

[0071] When the flywheel energy storage unit battery state of charge and the lithium battery energy storage unit battery state of charge are in the shallow charge and discharge area, the response power of the flywheel energy storage unit is controlled to preferentially output to charge or discharge;

[0072] When the battery state of charge of the flywheel energy storage unit and the battery state of charge of the lithium battery energy storage unit are in the deep charge and discharge region, the lithium battery energy storage unit is controlled to output the response power for charging or discharging preferentially.

[0073] When the battery state of charge of the flywheel energy storage unit and the battery state of charge of the lithium battery energy storage unit are in any energy storage region except the shallow charge and discharge region and the deep charge and discharge region, if the battery state of charge percentage of the flywheel energy storage unit is greater than the battery state of charge percentage of the lithium battery energy storage unit, the lithium battery energy storage unit is controlled to output the response power for charging preferentially, and the flywheel energy storage unit is controlled to output the response power for discharging preferentially; if the battery state of charge percentage of the flywheel energy storage unit is less than the battery state of charge percentage of the lithium battery energy storage unit, the flywheel energy storage unit is controlled to output the response power for charging preferentially, and the lithium battery energy storage unit is controlled to output the response power for discharging preferentially.

[0074] In step 104, the output of the lithium battery energy storage unit and the flywheel energy storage unit is allocated according to the size relationship between the battery state of charge percentage of the lithium battery energy storage unit and the battery state of charge percentage of the flywheel energy storage unit in each energy storage region; after the output allocation, the response power of the lithium battery energy storage unit and the response power of the flywheel energy storage unit are controlled coordinately.

[0075] The embodiment of the present application also provides a power control device of a wind turbine and a hybrid energy storage system, as described in the following embodiment. Since the device solves the problem by the similar principle as the power control method of the wind turbine and the hybrid energy storage system, the implementation of the device can be referred to the implementation of the power control method of the wind turbine and the hybrid energy storage system, and the repeated parts will not be described herein. Figure 5 Fig. 1 is a schematic diagram of a power control device of a wind turbine and a hybrid energy storage system in the embodiment of the present application, the hybrid energy storage system comprising a lithium battery energy storage unit and a flywheel energy storage unit, and the device comprising:

[0076] The power acquisition module 501 is configured to acquire the wind turbine power output by the wind turbine, and acquire the inertia response of the hybrid energy storage system and the active power required for primary frequency modulation;

[0077] The response power determination module 502 is configured to: when the power grid frequency at the power station grid connection point is within the frequency modulation dead zone, decompose the wind turbine power to obtain a low-frequency component and a high-frequency component of the wind turbine power, determine the low-frequency component as the wind turbine grid connection power, determine the high-frequency component as the fluctuation suppression power of the hybrid energy storage system, re-decompose the fluctuation suppression power, and determine a low-frequency component obtained after the re-decomposition as the response power of the lithium battery energy storage unit and a high-frequency component obtained after the re-decomposition as the response power of the flywheel energy storage unit; and when the power grid frequency at the power station grid connection point is outside the frequency modulation dead zone, decompose the active power required for inertia response and primary frequency modulation to obtain a low-frequency component and a high-frequency component of the hybrid energy storage system, determine the low-frequency component of the hybrid energy storage system as the response power of the lithium battery energy storage unit, and determine the high-frequency component of the hybrid energy storage system as the response power of the flywheel energy storage unit.

[0078] The energy storage region division module 503 is configured to: obtain the lithium battery energy storage unit battery state of charge percentage and the flywheel energy storage unit battery state of charge percentage, and perform energy storage region division on the lithium battery energy storage unit and the flywheel energy storage unit respectively according to the lithium battery energy storage unit battery state of charge percentage and the flywheel energy storage unit battery state of charge percentage, to obtain a plurality of corresponding energy storage regions.

[0079] The response power cooperative control module 504 is configured to: according to the size relationship between the lithium battery energy storage unit battery state of charge percentage and the flywheel energy storage unit battery state of charge percentage in each energy storage region, allocate the output of the lithium battery energy storage unit and the flywheel energy storage unit; and after the output allocation, cooperatively control the response power of the lithium battery energy storage unit and the response power of the flywheel energy storage unit.

[0080] In an embodiment, the response power determination module 502 is specifically configured to:

[0081] The ICEEMDAN complete ensemble empirical mode decomposition method is adopted to perform cyclic decomposition on the fluctuation suppression power, and the residual signal in the complete ensemble empirical mode decomposition method after the decomposition is updated until the residual signal is a monotonic signal, the cyclic decomposition of the fluctuation suppression power is stopped, and the cyclic-decomposed fluctuation suppression power is obtained.

[0082] According to the preset condition, the low-frequency component obtained after the re-decomposition and the high-frequency component obtained after the re-decomposition are determined from the cyclic-decomposed fluctuation suppression power, the low-frequency component obtained after the re-decomposition is determined as the response power of the lithium battery energy storage unit, and the high-frequency component obtained after the re-decomposition is determined as the response power of the flywheel energy storage unit.

[0083] In an embodiment, the energy storage region division module 503 is specifically configured to:

[0084] For lithium battery energy storage units, the energy storage area with a battery state of charge percentage of the lithium battery energy storage unit in the range of [0, 0.2) is determined as an over-discharge area; the energy storage area with a battery state of charge percentage of the lithium battery energy storage unit in the range of [0.2, 0.3) is determined as a deep charge area; the energy storage area with a battery state of charge percentage of the lithium battery energy storage unit in the range of [0.3, 0.7) is determined as a shallow charge and shallow discharge area; the energy storage area with a battery state of charge percentage of the lithium battery energy storage unit in the range of [0.7, 0.8) is determined as a deep discharge area; and the energy storage area with a battery state of charge percentage of the lithium battery energy storage unit in the range of [0.8, 1.0] is determined as an overcharge area;

[0085] For the flywheel energy storage unit, the energy storage area where the battery state of charge percentage of the flywheel energy storage unit is in the range of [0 to 0.1) is determined as the over-discharge area; the energy storage area where the battery state of charge percentage of the flywheel energy storage unit is in the range of [0.1 to 0.4) is determined as the deep charge area; the energy storage area where the battery state of charge percentage of the flywheel energy storage unit is in the range of [0.4 to 0.6) is determined as the shallow charge and shallow discharge area; the energy storage area where the battery state of charge percentage of the flywheel energy storage unit is in the range of [0.6 to 0.9) is determined as the deep discharge area; and the energy storage area where the battery state of charge percentage of the flywheel energy storage unit is in the range of [0.9 to 1.0] is determined as the over-charge area.

[0086] In one embodiment, the response power coordinated control module 504 is specifically configured to:

[0087] When the charge state of the flywheel energy storage unit and the charge state of the lithium battery energy storage unit are both in the shallow charge and discharge area, the response power of the flywheel energy storage unit is controlled to give priority to charging or discharging;

[0088] When the battery state of charge of the flywheel energy storage unit and the battery state of charge of the lithium battery energy storage unit are both in the deep charge and discharge region, the response power of the lithium battery energy storage unit is controlled to prioritize output for charging or discharging;

[0089] When the battery state of charge of the flywheel energy storage unit and the battery state of charge of the lithium battery energy storage unit are in any energy storage area other than the shallow charge and shallow discharge area and the deep charge and discharge area, if the battery state of charge percentage of the flywheel energy storage unit is greater than the battery state of charge percentage of the lithium battery energy storage unit, the response power of the lithium battery energy storage unit is controlled to prioritize output for charging, and the response power of the flywheel energy storage unit is controlled to prioritize output for discharging; if the battery state of charge percentage of the flywheel energy storage unit is less than the battery state of charge percentage of the lithium battery energy storage unit, the response power of the flywheel energy storage unit is controlled to prioritize output for charging, and the response power of the lithium battery energy storage unit is controlled to prioritize output for discharging.

[0090] The embodiment of the present application further provides a computer device, which comprises a memory, a processor and a computer program stored in the memory and capable of running on the processor, and the processor implements the power control method of the fan and the hybrid energy storage system when running the computer program.

[0091] The embodiment of the present application further provides a computer readable storage medium, which stores a computer program, and the computer program implements the power control method of the fan and the hybrid energy storage system when being executed by a processor.

[0092] The embodiment of the present application further provides a computer program product, which comprises a computer program, and the computer program implements the power control method of the fan and the hybrid energy storage system when being executed by a processor.

[0093] In the embodiment of the present application, the fan power output by the fan is acquired, the inertia response of the hybrid energy storage system and the active power required for primary frequency modulation are acquired, when the power grid frequency at the power station grid-connected point is within the frequency modulation dead zone, the fan power is decomposed to obtain a low-frequency component and a high-frequency component of the fan power, the low-frequency component is determined as the fan grid-connected power, the high-frequency component is determined as the fluctuation damping power of the hybrid energy storage system, the fluctuation damping power is decomposed again, the low-frequency component obtained after the decomposition is determined as the response power of the lithium battery energy storage unit, and the high-frequency component obtained after the decomposition is determined as the response power of the flywheel energy storage unit; when the power grid frequency at the power station grid-connected point is outside the frequency modulation dead zone, the inertia response and the active power required for primary frequency modulation are decomposed to obtain a low-frequency component and a high-frequency component of the hybrid energy storage system, the low-frequency component of the hybrid energy storage system is determined as the response power of the lithium battery energy storage unit, and the high-frequency component of the hybrid energy storage system is determined as the response power of the flywheel energy storage unit; the percentage of the state of charge of the lithium battery energy storage unit and the percentage of the state of charge of the flywheel energy storage unit are acquired, the lithium battery energy storage unit and the flywheel energy storage unit are respectively divided into energy storage regions according to the percentage of the state of charge of the lithium battery energy storage unit and the percentage of the state of charge of the flywheel energy storage unit, and a plurality of corresponding energy storage regions are obtained; the output of the lithium battery energy storage unit and the flywheel energy storage unit is distributed according to the size relationship between the percentage of the state of charge of the lithium battery energy storage unit and the percentage of the state of charge of the flywheel energy storage unit in each energy storage region; and the response power of the lithium battery energy storage unit and the response power of the flywheel energy storage unit are cooperatively controlled after the output distribution. In the above process, the embodiment of the present application determines the response power of the lithium battery energy storage unit and the response power of the flywheel energy storage unit based on the fan power and the inertia response of the hybrid energy storage system and the active power required for primary frequency modulation, and cooperatively controls the response power by using the hybrid energy storage mode of the flywheel energy storage unit plus the lithium battery energy storage unit. Therefore, the reasonable distribution of the output of the fan and the hybrid energy storage system is realized, the fluctuation risk of the power grid frequency is reduced, and the stability of the power grid is ensured.

[0094] Those skilled in the art will understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can adopt a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer usable storage media containing computer usable program code (including but not limited to disk storage, CD-ROM, optical storage, etc.).

[0095] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flow or blocks Figure 1 one or more flow or blocks

[0096] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flow or blocks Figure 1 one or more flow or blocks

[0097] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flow or blocks Figure 1 one or more flow or blocks

[0098] The above-described specific embodiments, the purpose, technical solutions and advantages of the present application are further described in detail, it should be understood that the above-described is only the specific embodiments of the present application, and is not used to limit the protection scope of the present application, any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A method of power control for a wind farm and hybrid energy storage system, characterized by, The hybrid energy storage system comprises a lithium battery energy storage unit and a flywheel energy storage unit, and the method comprises: acquiring wind turbine output power, acquiring inertia response of the hybrid energy storage system and active power required for primary frequency modulation; when the power grid frequency at the power station grid connection point is within the frequency modulation dead zone, the wind turbine output power is decomposed to obtain a low-frequency component and a high-frequency component, the low-frequency component is determined as wind turbine grid connection power, the high-frequency component is determined as fluctuation damping power of the hybrid energy storage system, the fluctuation damping power is re-decomposed, the low-frequency component obtained after re-decomposition is determined as response power of the lithium battery energy storage unit, and the high-frequency component obtained after re-decomposition is determined as response power of the flywheel energy storage unit; when the power grid frequency at the power station grid connection point is outside the frequency modulation dead zone, the inertia response and the active power required for primary frequency modulation are decomposed to obtain a low-frequency component and a high-frequency component of the hybrid energy storage system, the low-frequency component of the hybrid energy storage system is determined as response power of the lithium battery energy storage unit, and the high-frequency component of the hybrid energy storage system is determined as response power of the flywheel energy storage unit; acquiring the state of charge percentage of the lithium battery energy storage unit and the state of charge percentage of the flywheel energy storage unit, and dividing the lithium battery energy storage unit and the flywheel energy storage unit into energy storage regions according to the state of charge percentage of the lithium battery energy storage unit and the state of charge percentage of the flywheel energy storage unit, to obtain a plurality of corresponding energy storage regions; allocating the output of the lithium battery energy storage unit and the flywheel energy storage unit according to the size relationship between the state of charge percentage of the lithium battery energy storage unit and the state of charge percentage of the flywheel energy storage unit in each energy storage region; and performing collaborative control on the response power of the lithium battery energy storage unit and the response power of the flywheel energy storage unit after the output allocation.

2. The method of claim 1, wherein, The re-decomposition of the fluctuation damping power, the low-frequency component obtained after the re-decomposition being determined as the response power of the lithium battery energy storage unit, and the high-frequency component obtained after the re-decomposition being determined as the response power of the flywheel energy storage unit comprise: performing cyclic decomposition on the fluctuation damping power by using an ICEEMDAN complete ensemble empirical mode decomposition method, updating a residual signal in the complete ensemble empirical mode decomposition method after decomposition, and stopping the cycle when the residual signal is a monotonic signal, to obtain the fluctuation damping power after cyclic decomposition; determining the low-frequency component obtained after re-decomposition and the high-frequency component obtained after re-decomposition from the fluctuation damping power after cyclic decomposition according to a preset condition, determining the low-frequency component obtained after re-decomposition as the response power of the lithium battery energy storage unit, and determining the high-frequency component obtained after re-decomposition as the response power of the flywheel energy storage unit.

3. The method of claim 1, wherein, The division of the lithium battery energy storage unit and the flywheel energy storage unit into energy storage regions according to the state of charge percentage of the lithium battery energy storage unit and the state of charge percentage of the flywheel energy storage unit, to obtain a plurality of corresponding energy storage regions, comprises: For the lithium battery energy storage unit, the energy storage region with the lithium battery energy storage unit battery state of charge percentage in the range of [0, 0.2) is determined as the over-discharge region; the energy storage region with the lithium battery energy storage unit battery state of charge percentage in the range of [0.2, 0.3) is determined as the deep charge region; the energy storage region with the lithium battery energy storage unit battery state of charge percentage in the range of [0.3, 0.7) is determined as the shallow charge and discharge region; the energy storage region with the lithium battery energy storage unit battery state of charge percentage in the range of [0.7, 0.8) is determined as the deep discharge region; and the energy storage region with the lithium battery energy storage unit battery state of charge percentage in the range of [0.8, 1.0] is determined as the over-charge region; For the flywheel energy storage unit, the energy storage region with the flywheel energy storage unit battery state of charge percentage in the range of [0-0.1) is determined as the over-discharge region; the energy storage region with the flywheel energy storage unit battery state of charge percentage in the range of [0.1-0.4) is determined as the deep charge region; the energy storage region with the flywheel energy storage unit battery state of charge percentage in the range of [0.4-0.6) is determined as the shallow charge and discharge region; the energy storage region with the flywheel energy storage unit battery state of charge percentage in the range of [0.6-0.9) is determined as the deep discharge region; and the energy storage region with the flywheel energy storage unit battery state of charge percentage in the range of [0.9-1.0] is determined as the over-charge region.

4. The method of claim 3, wherein, According to the size relationship between the lithium battery energy storage unit battery state of charge percentage and the flywheel energy storage unit battery state of charge percentage in each energy storage region, the output of the lithium battery energy storage unit and the flywheel energy storage unit is allocated; After the output allocation, the response power of the lithium battery energy storage unit and the response power of the flywheel energy storage unit are cooperatively controlled, including: When the flywheel energy storage unit battery state of charge and the lithium battery energy storage unit battery state of charge are both in the shallow charge and discharge region, the response power of the flywheel energy storage unit is controlled to preferentially output for charging or discharging; When the flywheel energy storage unit battery state of charge and the lithium battery energy storage unit battery state of charge are both in the deep charge and discharge region, the response power of the lithium battery energy storage unit is controlled to preferentially output for charging or discharging; When the flywheel energy storage unit battery state of charge and the lithium battery energy storage unit battery state of charge are in any energy storage region other than the shallow charge and discharge region and the deep charge and discharge region, if the flywheel energy storage unit battery state of charge percentage is greater than the lithium battery energy storage unit battery state of charge percentage, the response power of the lithium battery energy storage unit is controlled to preferentially output for charging, and the response power of the flywheel energy storage unit is controlled to preferentially output for discharging; if the flywheel energy storage unit battery state of charge percentage is less than the lithium battery energy storage unit battery state of charge percentage, the response power of the flywheel energy storage unit is controlled to preferentially output for charging, and the response power of the lithium battery energy storage unit is controlled to preferentially output for discharging.

5. A power control apparatus for a wind farm and hybrid energy storage system, characterized by, The hybrid energy storage system includes a lithium battery energy storage unit and a flywheel energy storage unit, and the device includes: a power acquisition module, configured to acquire a fan power output by a fan, and acquire an inertia response of the hybrid energy storage system and an active power required for primary frequency modulation; The response power determination module is configured to: perform cyclic decomposition on the fluctuation damping power by using an ICEEMDAN complete ensemble empirical mode decomposition method, update a residual signal in the complete ensemble empirical mode decomposition method after decomposition, and stop the cycle until the residual signal is a monotonic signal, to obtain the fluctuation damping power after cyclic decomposition; and determine, according to a preset condition, a low-frequency component obtained after re-decomposition and a high-frequency component obtained after re-decomposition from the fluctuation damping power after cyclic decomposition, determine the low-frequency component obtained after re-decomposition as the response power of the lithium battery energy storage unit, and determine the high-frequency component obtained after re-decomposition as the response power of the flywheel energy storage unit. The energy storage region division module is configured to: obtain a lithium battery energy storage unit battery state of charge percentage and a flywheel energy storage unit battery state of charge percentage, and divide the lithium battery energy storage unit and the flywheel energy storage unit into energy storage regions according to the lithium battery energy storage unit battery state of charge percentage and the flywheel energy storage unit battery state of charge percentage, to obtain a plurality of corresponding energy storage regions. The response power cooperative control module is configured to: distribute the output of the lithium battery energy storage unit and the flywheel energy storage unit according to the size relationship between the lithium battery energy storage unit battery state of charge percentage and the flywheel energy storage unit battery state of charge percentage in each energy storage region; and perform cooperative control on the response power of the lithium battery energy storage unit and the response power of the flywheel energy storage unit after the output distribution.

6. The apparatus of claim 5, wherein, The response power determination module is specifically configured to: perform cyclic decomposition on the fluctuation damping power by using an ICEEMDAN complete ensemble empirical mode decomposition method, update a residual signal in the complete ensemble empirical mode decomposition method after decomposition, and stop the cycle until the residual signal is a monotonic signal, to obtain the fluctuation damping power after cyclic decomposition; and determine, according to a preset condition, a low-frequency component obtained after re-decomposition and a high-frequency component obtained after re-decomposition from the fluctuation damping power after cyclic decomposition, determine the low-frequency component obtained after re-decomposition as the response power of the lithium battery energy storage unit, and determine the high-frequency component obtained after re-decomposition as the response power of the flywheel energy storage unit. The energy storage region division module is specifically configured to:

7. The apparatus of claim 5, wherein, for the lithium battery energy storage unit, determine an energy storage region with a lithium battery energy storage unit battery state of charge percentage in a range of [0, 0.2) as an over-discharge region; determine an energy storage region with a lithium battery energy storage unit battery state of charge percentage in a range of [0.2, 0.3) as a deep charge region; determine an energy storage region with a lithium battery energy storage unit battery state of charge percentage in a range of [0.3, 0.7) as a shallow charge and discharge region; and determine an energy storage region with a lithium battery energy storage unit battery state of charge percentage in a range of [0.7, 0.8) as a deep discharge region; determine an energy storage region with a lithium battery energy storage unit battery state of charge percentage in a range of [0.8, 1.0] as an over-charge region. ​ For the flywheel energy storage unit, the energy storage region with the flywheel energy storage unit battery state of charge percentage in the range of [0-0.1) is determined as the over-discharge region; the energy storage region with the flywheel energy storage unit battery state of charge percentage in the range of [0.1-0.4) is determined as the deep charge region; the energy storage region with the flywheel energy storage unit battery state of charge percentage in the range of [0.4-0.6) is determined as the shallow charge and discharge region; the energy storage region with the flywheel energy storage unit battery state of charge percentage in the range of [0.6-0.9) is determined as the deep discharge region; and the energy storage region with the flywheel energy storage unit battery state of charge percentage in the range of [0.9-1.0] is determined as the over-charge region.

8. The apparatus of claim 7, wherein, The response power cooperative control module is specifically configured to: when the flywheel energy storage unit battery state of charge and the lithium battery energy storage unit battery state of charge are both in the shallow charge and discharge region, controlling the flywheel energy storage unit to preferentially output the response power for charging or discharging; when the flywheel energy storage unit battery state of charge and the lithium battery energy storage unit battery state of charge are both in the deep charge and discharge region, controlling the lithium battery energy storage unit to preferentially output the response power for charging or discharging; when the flywheel energy storage unit battery state of charge and the lithium battery energy storage unit battery state of charge are in any energy storage region except the shallow charge and discharge region and the deep charge and discharge region, if the flywheel energy storage unit battery state of charge percentage is greater than the lithium battery energy storage unit battery state of charge percentage, controlling the lithium battery energy storage unit to preferentially output the response power for charging and controlling the flywheel energy storage unit to preferentially output the response power for discharging; if the flywheel energy storage unit battery state of charge percentage is less than the lithium battery energy storage unit battery state of charge percentage, controlling the flywheel energy storage unit to preferentially output the response power for charging and controlling the lithium battery energy storage unit to preferentially output the response power for discharging.

9. A computer device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor executes the computer program to implement the method of any one of claims 1 to 4.

10. A computer-readable storage medium, characterized in that, The computer readable storage medium stores a computer program, and the computer program is executed by the processor to implement the method of any one of claims 1 to 4.

11. A computer program product, characterised in that, The computer program product comprises a computer program, and the computer program is executed by the processor to implement the method of any one of claims 1 to 4.

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