Flywheel energy storage primary frequency modulation optimization control method and system based on variable droop coefficient

Abstract

The invention discloses a flywheel energy storage primary frequency modulation optimization control method and system based on a variable droop coefficient, and belongs to the technical field of flywheel energy storage. The method comprises the following steps: establishing a frequency deviation model at a flywheel energy storage system bus after power grid frequency fluctuation; based on the frequency deviation model, determining a power demand of flywheel energy storage participating in primary frequency modulation; determining a rotating speed demand model which the flywheel energy storage needs to reach based on the power demand that the energy storage participates in primary frequency modulation; and based on the rotating speed demand model, determining flywheel energy storage action depth participating in primary frequency regulation, and performing optimization control on flywheel energy storage primary frequency regulation according to the flywheel energy storage action depth. By adjusting the actual motion depth of flywheel energy storage, the primary frequency modulation capability of the power grid can be improved by effectively utilizing the flexible adjustment source.

Description

Technical Field

[0001] The present invention relates to the technical field of flywheel energy storage, and more specifically, to a flywheel energy storage primary frequency modulation optimization control method and system based on a variable droop coefficient. Background Art

[0003] In recent years, the demonstration and application of flywheel energy storage at home and abroad has been gradually promoted. Flywheel energy storage technology has advantages in primary frequency regulation and AGC regulation due to its fast response and high power density. At present, certain research progress has also been made in the application mode and control of flywheel energy storage in primary frequency regulation.

[0004] However, in the case of energy storage systems participating in primary frequency modulation applications, the droop coefficient rule is used through the power-frequency relationship curve, that is, a fixed droop coefficient is used for control. When the frequency fluctuates, the fixed droop control mode always responds according to fixed rules and cannot release different powers according to different frequencies, which easily causes over-frequency modulation. Summary of the invention

[0005] In view of the above problems, the present invention proposes a flywheel energy storage primary frequency modulation optimization control method based on variable droop coefficient, comprising:

[0006] Establish a frequency deviation model at the flywheel energy storage system bus after grid frequency fluctuations;

[0007] Based on the frequency deviation model, determining the power demand of flywheel energy storage participating in primary frequency regulation;

[0008] Based on the power demand of energy storage participating in primary frequency regulation, determine the speed demand model that the flywheel energy storage needs to achieve;

[0009] Based on the speed demand model, the flywheel energy storage action depth participating in the primary frequency regulation is determined, and according to the flywheel energy storage action depth, the flywheel energy storage primary frequency regulation is optimized and controlled.

[0010] Optionally, the frequency deviation model at the flywheel energy storage system bus after the grid frequency fluctuation is established as follows:

[0011] Δf i =f e -f i

[0012] Where Δf i is the frequency deviation caused by load fluctuation, f i is the real-time frequency value collected at the bus where the flywheel energy storage system is located, f e is the rated frequency.

[0013] Optionally, based on the frequency deviation model, determining the power demand of flywheel energy storage participating in primary frequency regulation includes:

[0014] Based on the frequency deviation model, the size of the frequency deviation is determined; based on the size of the frequency deviation and the grid dead zone constraint, a characteristic relationship between the frequency deviation and the flywheel energy storage power compensation amount is established according to the variable droop coefficient method; based on the characteristic relationship, a power demand model is established; based on the power demand model, the power demand for the flywheel energy storage to participate in primary frequency regulation is determined.

[0015] Optional, power demand model, as follows:

[0016]

[0017] Among them, ΔP i is the power demand of flywheel energy storage participating in primary frequency regulation, K i is the variable droop coefficient for active power control of flywheel energy storage.

[0018] Optionally, the variable droop coefficient is assigned as follows:

[0019]

[0020] Among them, K ref is the inherent droop coefficient of the flywheel energy storage system, a is a constant and is greater than 1, b is a constant and b>a.

[0021] Optionally, the speed requirement model that the flywheel energy storage needs to achieve is as follows:

[0022]

[0023] Among them, P0 is the output power value of the flywheel at the current speed, J F is the moment of inertia of the flywheel, is the angular velocity that the flywheel needs to reach at time i.

[0024] Optionally, an action depth model is established based on the speed demand model, and based on the action depth model, the depth of the flywheel energy storage action participating in a frequency regulation is determined.

[0025] Optional, action depth model, as follows:

[0026]

[0027] Among them, P max.Fly is the maximum power output value of the flywheel energy storage system, is the speed value of the flywheel energy storage system at time i, P i.Fly is the actual output value of the flywheel energy storage used for primary frequency regulation, ω minis the minimum speed value of the flywheel energy storage system, ω max is the maximum speed value of the flywheel energy storage system.

[0028] On the other hand, the present invention also proposes a flywheel energy storage primary frequency modulation optimization control system based on a variable droop coefficient, comprising:

[0029] A frequency fluctuation judgment module is used to establish a frequency deviation model at the flywheel energy storage system bus after the grid frequency fluctuates;

[0030] A primary frequency regulation power demand calculation module, used to determine the power demand of flywheel energy storage participating in primary frequency regulation based on the frequency deviation model;

[0031] The flywheel energy storage speed demand calculation module is used to determine the speed demand model that the flywheel energy storage needs to achieve based on the power demand of the energy storage participating in the primary frequency regulation;

[0032] The feedback adjustment module is used to determine the depth of the flywheel energy storage action participating in the primary frequency regulation based on the speed demand model, and optimize the control of the flywheel energy storage primary frequency regulation according to the flywheel energy storage action depth.

[0033] Optionally, the frequency deviation model at the flywheel energy storage system bus after the grid frequency fluctuation is established as follows:

[0034] Δf i =f e -f i

[0035] Where Δf i is the frequency deviation caused by load fluctuation, f i is the real-time frequency value collected at the bus where the flywheel energy storage system is located, f e is the rated frequency.

[0036] Optionally, based on the frequency deviation model, determining the power demand of flywheel energy storage participating in primary frequency regulation includes:

[0037] Based on the frequency deviation model, the size of the frequency deviation is determined; based on the size of the frequency deviation and the grid dead zone constraint, a characteristic relationship between the frequency deviation and the flywheel energy storage power compensation amount is established according to the variable droop coefficient method; based on the characteristic relationship, a power demand model is established; based on the power demand model, the power demand for the flywheel energy storage to participate in primary frequency regulation is determined.

[0038] Optional, power demand model, as follows:

[0039]

[0040] Where ΔP iis the power demand of flywheel energy storage participating in primary frequency regulation, K i is the variable droop coefficient for active power control of flywheel energy storage.

[0041] Optionally, the variable droop coefficient is assigned as follows:

[0042]

[0043] Among them, K ref is the inherent droop coefficient of the flywheel energy storage system, a is a constant and is greater than 1, b is a constant and b>a.

[0044] Optionally, the speed requirement model that the flywheel energy storage needs to achieve is as follows:

[0045]

[0046] Among them, P0 is the output power value of the flywheel at the current speed, J F is the moment of inertia of the flywheel, is the angular velocity that the flywheel needs to reach at time i.

[0047] Optionally, an action depth model is established based on the speed demand model, and based on the action depth model, the depth of the flywheel energy storage action participating in a frequency regulation is determined.

[0048] Optional, action depth model, as follows:

[0049]

[0050] Among them, P max.Fly is the maximum power output value of the flywheel energy storage system, is the speed value of the flywheel energy storage system at time i, P i.Fly is the actual output value of the flywheel energy storage used for primary frequency regulation, ω min is the minimum speed value of the flywheel energy storage system, ω max is the maximum speed value of the flywheel energy storage system.

[0051] In yet another aspect, the present invention further provides a computing device, comprising: one or more processors;

[0052] a processor for executing one or more programs;

[0053] When the one or more programs are executed by the one or more processors, the above-described method is implemented.

[0054] In yet another aspect, the present invention further provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed, the method described above is implemented.

[0055] Compared with the prior art, the present invention has the following beneficial effects:

[0056] The present invention provides a flywheel energy storage primary frequency regulation optimization control method based on variable droop coefficient, including: establishing a frequency deviation model at the bus of the flywheel energy storage system after the power grid frequency fluctuates; based on the frequency deviation model, determining the power demand of the flywheel energy storage participating in the primary frequency regulation; based on the power demand of the energy storage participating in the primary frequency regulation, determining the speed demand model that the flywheel energy storage needs to achieve; based on the speed demand model, determining the depth of action of the flywheel energy storage participating in the primary frequency regulation, and optimizing the primary frequency regulation of the flywheel energy storage according to the depth of action of the flywheel energy storage. The present invention can effectively utilize the flexible regulation source to improve the primary frequency regulation capability of the power grid by adjusting the actual action depth of the flywheel energy storage. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 is a flow chart of the method of the present invention;

[0058] Figure 2 is a flow chart of an embodiment of the method of the present invention;

[0059] Figure 3 A primary frequency modulation control block diagram of an embodiment of the method of the present invention;

[0060] Figure 4 It is a structural diagram of the system of the present invention. DETAILED DESCRIPTION

[0061] Now, exemplary embodiments of the present invention are described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms used in the exemplary embodiments shown in the accompanying drawings are not intended to limit the present invention. In the accompanying drawings, the same units / elements are marked with the same reference numerals.

[0062] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0063] Embodiment 1:

[0064] The present invention proposes a flywheel energy storage primary frequency modulation optimization control method based on variable droop coefficient, such as Figure 1 As shown, including:

[0065] Step 1: Establish a frequency deviation model at the bus of the flywheel energy storage system after the grid frequency fluctuates;

[0066] Step 2: Based on the frequency deviation model, determine the power demand of the flywheel energy storage participating in the primary frequency regulation;

[0067] Step 3: Based on the power demand of energy storage participating in primary frequency regulation, determine the speed demand model that the flywheel energy storage needs to achieve;

[0068] Step 4: Based on the speed demand model, determine the flywheel energy storage action depth participating in the primary frequency regulation, and optimize the flywheel energy storage primary frequency regulation according to the flywheel energy storage action depth.

[0069] Among them, the frequency deviation model at the bus of the flywheel energy storage system after the grid frequency fluctuation is established as follows:

[0070] Δf i =f e -f i

[0071] Where Δf i is the frequency deviation caused by load fluctuation, f i is the real-time frequency value collected at the bus where the flywheel energy storage system is located, f e is the rated frequency.

[0072] Wherein, based on the frequency deviation model, determining the power demand of flywheel energy storage participating in primary frequency regulation includes:

[0073] Based on the frequency deviation model, the size of the frequency deviation is determined; based on the size of the frequency deviation and the grid dead zone constraint, a characteristic relationship between the frequency deviation and the flywheel energy storage power compensation amount is established according to the variable droop coefficient method; based on the characteristic relationship, a power demand model is established; based on the power demand model, the power demand for the flywheel energy storage to participate in primary frequency regulation is determined.

[0074] The power demand model is as follows:

[0075]

[0076] Among them, ΔP i is the power demand of flywheel energy storage participating in primary frequency regulation, K i is the variable droop coefficient for active power control of flywheel energy storage.

[0077] Among them, the assignment formula of variable droop coefficient is as follows:

[0078]

[0079] Among them, K ref is the inherent droop coefficient of the flywheel energy storage system, a is a constant and is greater than 1, b is a constant and b>a.

[0080] Among them, the speed requirement model that the flywheel energy storage needs to achieve is as follows:

[0081]

[0082] Among them, P0 is the output power value of the flywheel at the current speed, J F is the moment of inertia of the flywheel, is the angular velocity that the flywheel needs to reach at time i.

[0083] Wherein, based on the rotation speed demand model, an action depth model is established, and based on the action depth model, the flywheel energy storage action depth participating in a frequency regulation is determined.

[0084] Among them, the action depth model is as follows:

[0085]

[0086] Among them, P max.Fly is the maximum power output value of the flywheel energy storage system, is the speed value of the flywheel energy storage system at time i, P i.Fly is the actual output value of the flywheel energy storage used for primary frequency regulation, ω min is the minimum speed value of the flywheel energy storage system, ω max is the maximum speed value of the flywheel energy storage system.

[0087] The present invention is further described below with reference to specific cases:

[0088] Case implementation steps Figure 2 As shown, including:

[0089] (1) Establish a frequency deviation model at the flywheel energy storage system bus after grid frequency fluctuations;

[0090] (2) Determine the magnitude of frequency fluctuations, combine grid dead zone constraints, determine the timing of flywheel energy storage action, apply variable droop coefficient adjustment method, establish the characteristic relationship between frequency deviation and flywheel energy storage power compensation, and determine the power demand model for flywheel energy storage to participate in primary frequency regulation;

[0091] (3) By feeding back the power demand change step signal to the energy storage system and combining it with the current state of the flywheel energy storage speed, a correlation relationship between the power demand and the state quantity that the flywheel energy storage speed needs to reach is established, and a speed demand model that the flywheel energy storage needs to reach is determined;

[0092] (4) Based on the speed variation model, combined with the grid frequency over-limit constraint and the upper and lower limit constraints of the flywheel speed, the depth of the flywheel energy storage action participating in the primary frequency regulation is determined.

[0093] Among them, after determining that the grid frequency deviates from the rated value, the frequency is collected through the frequency collection device at the bus where the flywheel energy storage system is located, and the real-time frequency value is subtracted from the rated value. The frequency deviation caused by load fluctuation is:

[0094] Δf i =f e -f i

[0095] Where Δf i Indicates the frequency deviation caused by load fluctuation; f i represents the real-time frequency value collected at the bus where the flywheel energy storage system is located, f e Indicates the rated frequency (50HZ in my country).

[0096] Among them, by judging the magnitude of frequency fluctuation and combining the grid dead zone constraint, the variable droop coefficient method is used to establish the characteristic relationship between frequency deviation and flywheel energy storage power compensation, and the power demand value of flywheel energy storage participating in primary frequency regulation is calculated by the following formula:

[0097]

[0098] Where ΔP i Indicates the power demand of flywheel energy storage participating in primary frequency regulation; K i Represents the variable droop factor for active power control of flywheel energy storage.

[0099] Among them, the value of the variable droop coefficient is calculated according to the degree of deviation of the grid frequency:

[0100]

[0101] Among them, K ref It represents the inherent droop coefficient of the flywheel energy storage system; a represents a constant and is greater than 1. In practical applications, it is adjusted according to the actual system; b represents a constant and b>a. In practical applications, it is adjusted according to the actual system.

[0102] After receiving the power demand information, combined with the power state corresponding to the current speed of the flywheel energy storage, the new state quantity of the flywheel speed corresponding to the power demand is calculated by the following formula:

[0103]

[0104] Wherein, P0 represents the output power value of the flywheel at the current speed; J F represents the moment of inertia of the flywheel; It represents the angular velocity that the flywheel needs to reach at time i.

[0105] Among them, considering the upper and lower limits of the flywheel energy storage speed, the action depth of the flywheel energy storage participating in the primary frequency regulation is determined according to the following formula:

[0106]

[0107] Among them, P max.Fly Indicates the maximum power output value of the flywheel energy storage system; represents the speed value of the flywheel energy storage system at time i; P i.Fly Indicates the actual output value of the flywheel energy storage used for primary frequency regulation; ω min Indicates the minimum speed value of the flywheel energy storage system; ω max Indicates the maximum speed value of the flywheel energy storage system.

[0108] Among them, the control block diagram of the above steps is as follows Figure 3 As shown, specifically including:

[0109] Among them, in step (1), the frequency fluctuation judgment module collects the real-time frequency signal f fed back by the frequency sensing logic control loop at the bus where the flywheel energy storage system is located. i After that, the real-time frequency value f i Subtract the actual frequency from the rated frequency by 50 Hz to get the deviation Δf between the actual frequency and the rated frequency. i , that is, Δf i =f i -50, and based on Δf i Make judgment and assign value: When -0.033HZ≤Δf i ≤0.033HZ, the primary frequency modulation power demand calculation module is not started, and step (1) is repeated; if 0.033HZ<Δf i <0.2HZ or -0.2HZ<Δf i <-0.033HZ, the primary frequency modulation power demand calculation module is started, and Δf i Send the primary frequency modulation power demand calculation module.

[0110] In step (2), the primary frequency modulation power demand calculation module is started and receives the frequency deviation Δf i , calculate the power demand value ΔP of the flywheel energy storage system i , that is, ΔP i =-K i Δf i , further judgment and assignment, and optimization adjustment of the required output size of the flywheel energy storage system include the following steps:

[0111] When 0.033HZ<|Δf i |≤0.083HZ, K ref Assign step trigger signal Ki , then the power demand |ΔP i |=-K ref Δf i , and ΔP i The parameter information is sent to the flywheel energy storage speed demand calculation module;

[0112] When 0.083HZ<|Δf i |≤0.133HZ, aK ref Assign step trigger signal K i , then the power demand |ΔP i |=-aK ref Δf i , and ΔP i The parameter information is sent to the flywheel energy storage speed demand calculation module;

[0113] When 0.133HZ<|Δf i |≤0.15HZ, bK ref Assign step trigger signal K i , then the power demand |ΔP i |=-bK ref Δf i , and ΔP i The parameter information is sent to the flywheel energy storage speed demand calculation module;

[0114] When 0.15HZ<|Δf i |<0.2HZ, assign ∞ to the step trigger signal K i , then the power demand |ΔP i |=-∞Δf i , and ΔP i The parameter information is sent to the flywheel energy storage speed demand calculation module.

[0115] Among them, in step (3), the flywheel energy storage speed demand calculation module is started and receives the power demand signal ΔP i , calculate the new state of the flywheel energy storage speed and will Passed to the feedback adjustment module.

[0116] Among them, in step (4), the feedback adjustment module starts and receives the new state demand of the flywheel energy storage speed According to the new state demand of the speed Different, divided into four areas, including:

[0117] Zone I is the lower restricted zone:

[0118] Zone II is the frequency adjustment zone:

[0119] Zone III is the speed return zone:

[0120] Zone IV is the upper restricted zone:

[0121] Among them, ω rate is the rated speed of the flywheel energy storage system.

[0122] Wherein, the feedback adjustment module in step (4) controls the flywheel energy storage unit to control the energy storage system, including the following steps:

[0123] And |P i.Fly |≤P max.Fly , then the flywheel energy storage system is P i.Fly =ΔP i The power size of +P0 releases or attracts power to the bus feeder of the flywheel energy storage system;

[0124] And |P i.Fly |>P max.Fly , then the flywheel energy storage system is P i.Fly =P max.Fly The power size releases or attracts power to the bus feeder of the flywheel energy storage system;

[0125] If P i.Fly =0, The flywheel energy storage system is based on P i.Fly =1%P e (P e The power of the flywheel energy storage system is the rated power of the flywheel energy storage system) and the power is released to the bus feeder to return the flywheel speed to 50%ω rate Operational status, preparing for the next frequency regulation service;

[0126] If P i.Fly =0, The energy storage system is based on P i.Fly =1%P e (P e The power of the energy storage system is the rated power of the energy storage system, which absorbs power from the bus feeder to return the flywheel speed to 50%ω rate Operational status, preparing for the next frequency regulation service;

[0127] Then the flywheel energy storage system does not work;

[0128] The flywheel energy storage system does not work.

[0129] The control command output by the feedback adjustment module in step (4) includes:

[0130] like And 0.033HZ<Δf i ≤0.083HZ,|P i.Fly |≤P max.Fly When , the output of the flywheel energy storage system is P i.Fly =ΔP i +P0=-(-K ref Δf i +P0), P i.Fly The charge and discharge status flag(i) = -1;

[0131] like And -0.083HZ<Δf i ≤-0.033HZ,|P i.Fly |≤P max.Fly When , the output of the flywheel energy storage system is P i.Fly =ΔP i +P0=-K ref Δf i +P0,P i.Fly The charge and discharge status flag(i) = 1;

[0132] like And 0.083HZ<Δf i ≤0.133HZ,|P i.Fly |≤P max.Fly When , the output of the flywheel energy storage system is P i.Fly =ΔP i +P0=-(-aK ref Δf i +P0), P i.Fly The charge and discharge status flag(i) = -1;

[0133] like And -0.133HZ<Δf i ≤-0.083HZ,|P i.Fly |≤P max.Fly When , the output of the flywheel energy storage system is P i.Fly =ΔP i +P0=-aK ref Δf i +P0,P i.Fly The charge and discharge status flag(i) = 1;

[0134] like And 0.133HZ<Δf i ≤0.15HZ,|P i.Fly |≤P max.Fly When , the output of the flywheel energy storage system is P i.Fly=ΔP i +P0=-(-bK ref Δf i +P0), P i.Fly The charge and discharge status flag(i) = -1;

[0135] like And -0.15HZ<Δf i ≤-0.133HZ,|P i.Fly |≤P max.Fly When , the output of the flywheel energy storage system is P i.Fly =ΔP i +P0=-bK ref Δf i +P0,P i.Fly The charge and discharge status flag(i) = 1;

[0136] like And 0.15HZ<Δf i <0.2HZ,|ΔP i |=-(-∞Δf i ), the output of the flywheel energy storage system is P i.Fly =ΔP i +P0=-P max.Fly , P i.Fly The charge and discharge status flag(i) = -1;

[0137] like And -0.2HZ<Δf i <-0.15HZ,ΔP i =-∞Δf i When , the output of the flywheel energy storage system is P i.Fly =ΔP i +P0=P max.Fly , P i.Fly The charge and discharge status flag(i) = 1;

[0138] like And 0.033HZ<Δf i <0.2HZ,|P i.Fly |>P max.Fly When , the output of the flywheel energy storage system is P i.Fly =ΔP i +P0=-P max.Fly , P i.Fly The charge and discharge status flag(i) = -1;

[0139] like And -0.2HZ<Δf i ≤-0.033HZ,|P i.Fly |>Pmax.Fly When , the output of the flywheel energy storage system is P i.Fly =ΔP i +P0=P max.Fly , P i.Fly The charge and discharge status flag(i) = 1;

[0140] If P i.Fly =0, The output of the flywheel energy storage system is P i.Fly =1%P e (P e is the rated power of the flywheel energy storage system), P i.Fly The charge and discharge status flag(i) = 1;

[0141] If P i.Fly =0, The output of the flywheel energy storage system is P i.Fly =-1%P e (P e is the rated power of the energy storage system), P i.Fly The charging and discharging status flag(i) = -1.

[0142] Among them, according to P i.Fly The positive and negative signs of P determine the charge and discharge state of the flywheel energy storage system. i.Fly <0, flag(i)=-1 indicates that the energy storage system is charging; P i.Fly >0, flag(i)=1 indicates that the energy storage system is discharging, and the power value |P i.Fly | and the charge and discharge status flag(i) of the flywheel energy storage system are sent to the feedback adjustment module, and the charge and discharge of the flywheel energy storage system is controlled by the feedback adjustment module to support the primary frequency regulation demand.

[0143] The present invention is based on the EMS system at the bus of the flywheel energy storage system, collects the state information and fluctuation degree data of the transmission grid frequency, and when the grid frequency fluctuates and crosses the dead zone, calculates the droop coefficient under different frequency fluctuation degrees, measures the power demand for the flywheel energy storage system and the corresponding speed demand, further considers the speed operating state and constraints of the flywheel energy storage system, determines the action timing of the flywheel energy storage system, and adjusts the actual action depth of the flywheel energy storage.

[0144] Embodiment 2:

[0145] The present invention also proposes a flywheel energy storage primary frequency modulation optimization control system 200 based on a variable droop coefficient, such as Figure 4 As shown, including:

[0146] The frequency fluctuation judgment module 201 is used to establish a frequency deviation model at the bus of the flywheel energy storage system after the grid frequency fluctuates;

[0147] A primary frequency regulation power demand calculation module 202 is used to determine the power demand of flywheel energy storage participating in primary frequency regulation based on the frequency deviation model;

[0148] The flywheel energy storage speed demand calculation module 203 is used to determine the speed demand model that the flywheel energy storage needs to achieve based on the power demand of the energy storage participating in the primary frequency regulation;

[0149] The feedback adjustment module 204 is used to determine the flywheel energy storage action depth participating in the primary frequency regulation based on the speed demand model, and optimize the flywheel energy storage primary frequency regulation according to the flywheel energy storage action depth.

[0150] Among them, the frequency deviation model at the bus of the flywheel energy storage system after the grid frequency fluctuation is established as follows:

[0151] Δf i =f e -f i

[0152] Where Δf i is the frequency deviation caused by load fluctuation, f i is the real-time frequency value collected at the bus where the flywheel energy storage system is located, f e is the rated frequency.

[0153] Wherein, based on the frequency deviation model, determining the power demand of flywheel energy storage participating in primary frequency regulation includes:

[0154] Based on the frequency deviation model, the size of the frequency deviation is determined; based on the size of the frequency deviation and the grid dead zone constraint, a characteristic relationship between the frequency deviation and the flywheel energy storage power compensation amount is established according to the variable droop coefficient method; based on the characteristic relationship, a power demand model is established; based on the power demand model, the power demand for the flywheel energy storage to participate in primary frequency regulation is determined.

[0155] The power demand model is as follows:

[0156]

[0157] Where ΔP i is the power demand of flywheel energy storage participating in primary frequency regulation, K i is the variable droop coefficient for active power control of flywheel energy storage.

[0158] Among them, the assignment formula of variable droop coefficient is as follows:

[0159]

[0160] Among them, K refis the inherent droop coefficient of the flywheel energy storage system, a is a constant and is greater than 1, b is a constant and b>a.

[0161] Among them, the speed requirement model that the flywheel energy storage needs to achieve is as follows:

[0162]

[0163] Among them, P0 is the output power value of the flywheel at the current speed, J F is the moment of inertia of the flywheel, is the angular velocity that the flywheel needs to reach at time i.

[0164] Wherein, based on the rotation speed demand model, an action depth model is established, and based on the action depth model, the flywheel energy storage action depth participating in a frequency regulation is determined.

[0165] Among them, the action depth model is as follows:

[0166]

[0167] Among them, P max.Fly is the maximum power output value of the flywheel energy storage system, is the speed value of the flywheel energy storage system at time i, P i.Fly is the actual output value of the flywheel energy storage used for primary frequency regulation, ω min is the minimum speed value of the flywheel energy storage system, ω max is the maximum speed value of the flywheel energy storage system.

[0168] The present invention can effectively utilize the flexible regulation source to enhance the primary frequency regulation capability of the power grid by adjusting the actual action depth of the flywheel energy storage.

[0169] Embodiment 3:

[0170] Based on the same inventive concept, the present invention also provides a computer device, which includes a processor and a memory, wherein the memory is used to store a computer program, the computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, which is suitable for implementing one or more instructions, and is specifically suitable for loading and executing one or more instructions in the computer storage medium to implement the corresponding method flow or corresponding functions, so as to implement the steps of the method in the above embodiment.

[0171] Embodiment 4:

[0172] Based on the same inventive concept, the present invention also provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device for storing programs and data. It is understandable that the computer-readable storage medium here can include both a built-in storage medium in a computer device and an extended storage medium supported by the computer device. The computer-readable storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by a processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the steps of the method in the above embodiment.

[0173] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes. The schemes in the embodiments of the present invention may be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0174] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0175] These computer program instructions may also be stored in a computer readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0176] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0177] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0178] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A flywheel energy storage primary frequency modulation optimization control method based on variable droop coefficient, characterized in that: include: Establish a frequency deviation model at the flywheel energy storage system bus after grid frequency fluctuations; Based on the frequency deviation model, determining the power demand of flywheel energy storage participating in primary frequency regulation; Based on the power demand of energy storage participating in primary frequency regulation, determine the speed demand model that the flywheel energy storage needs to achieve; Based on the speed demand model, the flywheel energy storage action depth participating in the primary frequency regulation is determined, and according to the flywheel energy storage action depth, the flywheel energy storage primary frequency regulation is optimized and controlled.

2. The flywheel energy storage primary frequency modulation optimization control method according to claim 1 is characterized in that: The established frequency deviation model at the flywheel energy storage system bus after grid frequency fluctuation is as follows: Δf i =f e -f i Where Δf i is the frequency deviation caused by load fluctuation, f i is the real-time frequency value collected at the bus where the flywheel energy storage system is located, f e is the rated frequency.

3. The flywheel energy storage primary frequency modulation optimization control method according to claim 1 is characterized in that: The determining, based on the frequency deviation model, the power demand of the flywheel energy storage participating in the primary frequency regulation includes: Based on the frequency deviation model, the size of the frequency deviation is determined; based on the size of the frequency deviation and the grid dead zone constraint, a characteristic relationship between the frequency deviation and the flywheel energy storage power compensation amount is established according to the variable droop coefficient method; based on the characteristic relationship, a power demand model is established; based on the power demand model, the power demand for the flywheel energy storage to participate in primary frequency regulation is determined.

4. The flywheel energy storage primary frequency modulation optimization control method according to claim 3 is characterized in that: The power demand model is as follows: Among them, ΔP i is the power demand of flywheel energy storage participating in primary frequency regulation, K i is the variable droop coefficient for active power control of flywheel energy storage.

5. The flywheel energy storage primary frequency modulation optimization control method according to claim 3 is characterized in that: The variable droop coefficient assignment formula is as follows: Among them, K ref is the inherent droop coefficient of the flywheel energy storage system, a is a constant and is greater than 1, b is a constant and b>a.

6. The flywheel energy storage primary frequency modulation optimization control method according to claim 1 is characterized in that: The speed requirement model that the flywheel energy storage needs to achieve is as follows: Among them, P0 is the output power value of the flywheel at the current speed, J F is the moment of inertia of the flywheel, is the angular velocity that the flywheel needs to reach at time i.

7. The flywheel energy storage primary frequency modulation optimization control method according to claim 1 is characterized in that: Based on the speed demand model, an action depth model is established, and based on the action depth model, the flywheel energy storage action depth participating in a frequency regulation is determined.

8. The flywheel energy storage primary frequency modulation optimization control method according to claim 7 is characterized in that: The action depth model is as follows: Among them, P max.Fly is the maximum power output value of the flywheel energy storage system, ω gi is the speed value of the flywheel energy storage system at time i, P i.Fly is the actual output value of the flywheel energy storage used for primary frequency regulation, ω min is the minimum speed value of the flywheel energy storage system, ω max is the maximum speed value of the flywheel energy storage system.

9. A flywheel energy storage primary frequency modulation optimization control system based on variable droop coefficient, characterized in that: include: A frequency fluctuation judgment module is used to establish a frequency deviation model at the flywheel energy storage system bus after the grid frequency fluctuates; A primary frequency regulation power demand calculation module, used to determine the power demand of flywheel energy storage participating in primary frequency regulation based on the frequency deviation model; The flywheel energy storage speed demand calculation module is used to determine the speed demand model that the flywheel energy storage needs to achieve based on the power demand of the energy storage participating in the primary frequency regulation; The feedback adjustment module is used to determine the depth of the flywheel energy storage action participating in the primary frequency regulation based on the speed demand model, and optimize the control of the flywheel energy storage primary frequency regulation according to the flywheel energy storage action depth.

10. The flywheel energy storage primary frequency modulation optimization control system according to claim 9, characterized in that: The established frequency deviation model at the flywheel energy storage system bus after grid frequency fluctuation is as follows: Δf i =f e -f i Where Δf i is the frequency deviation caused by load fluctuation, f i is the real-time frequency value collected at the bus where the flywheel energy storage system is located, f e is the rated frequency.

11. The flywheel energy storage primary frequency modulation optimization control system according to claim 9, characterized in that: The determining, based on the frequency deviation model, the power demand of the flywheel energy storage participating in the primary frequency regulation includes: Based on the frequency deviation model, the size of the frequency deviation is determined; based on the size of the frequency deviation and the grid dead zone constraint, a characteristic relationship between the frequency deviation and the flywheel energy storage power compensation amount is established according to the variable droop coefficient method; based on the characteristic relationship, a power demand model is established; based on the power demand model, the power demand for the flywheel energy storage to participate in primary frequency regulation is determined.

12. The flywheel energy storage primary frequency modulation optimization control system according to claim 11, characterized in that: The power demand model is as follows: Among them, ΔP i is the power demand of flywheel energy storage participating in primary frequency regulation, K i is the variable droop coefficient for active power control of flywheel energy storage.

13. The flywheel energy storage primary frequency modulation optimization control system according to claim 11, characterized in that: The variable droop coefficient assignment formula is as follows: Among them, K ref is the inherent droop coefficient of the flywheel energy storage system, a is a constant and is greater than 1, b is a constant and b>a.

14. The flywheel energy storage primary frequency modulation optimization control system according to claim 9, characterized in that: The speed requirement model that the flywheel energy storage needs to achieve is as follows: Among them, P0 is the output power value of the flywheel at the current speed, J F is the moment of inertia of the flywheel, is the angular velocity that the flywheel needs to reach at time i.

15. The flywheel energy storage primary frequency modulation optimization control system according to claim 9, characterized in that: Based on the speed demand model, an action depth model is established, and based on the action depth model, the flywheel energy storage action depth participating in a frequency regulation is determined.

16. The flywheel energy storage primary frequency modulation optimization control system according to claim 15, characterized in that: The action depth model is as follows: Among them, P max.Fly is the maximum power output value of the flywheel energy storage system, ω gi is the speed value of the flywheel energy storage system at time i, P i.Fly is the actual output value of the flywheel energy storage used for primary frequency regulation, ω min is the minimum speed value of the flywheel energy storage system, ω max is the maximum speed value of the flywheel energy storage system.

17. A computer device, characterized in that: include: one or more processors; a processor for executing one or more programs; When the one or more programs are executed by the one or more processors, the method according to any one of claims 1 to 8 is implemented.

18. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the computer program is executed, the method according to any one of claims 1 to 8 is implemented.

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