A frequency control method for energy storage system considering random fluctuations of new energy

Abstract

The present invention discloses a frequency regulation control method for an energy storage system taking into account random fluctuations of new energy, and belongs to the field of electric power technology. The method comprises the following steps: establishing a frequency response model of an electric power system taking into account energy storage; calculating the energy storage frequency regulation coefficient demand under load disturbance; calculating the energy storage frequency regulation coefficient demand increment containing random fluctuations of new energy; considering the energy storage frequency regulation coefficient demand under the load disturbance, calculating the frequency regulation energy demand of the energy storage system of the power system frequency response model under load disturbance; calculating the energy increment required for energy storage of the power system frequency response model containing random fluctuations of new energy.

Description

Technical Field

[0001] The present invention relates to the field of electric power technology, and in particular to a frequency modulation control method for an energy storage system taking into account random fluctuations of new energy. Background Art

[0002] Clean energy represented by wind and solar energy is gradually replacing traditional fossil energy, and my country's power system will show the characteristics of a high proportion of renewable energy gradually penetrating. However, the randomness and volatility of clean energy power generation will lead to intensified power fluctuations on the power supply side. At the same time, the low-inertia power system with a high proportion of power electronic equipment added makes the frequency change rate and frequency deviation of the power grid significantly increase when the power load is disturbed, which brings huge challenges to the frequency regulation of the power system. Therefore, it is necessary to introduce a new frequency regulation method to solve the frequency regulation problem of traditional frequency regulation units. The energy storage system has a fast response speed and high control accuracy, and can effectively participate in the rapid frequency regulation of the power system.

[0003] However, when facing load disturbances and fluctuations in renewable energy, if an energy storage system is used for frequency regulation, it is necessary to calculate its energy storage frequency regulation coefficient and the energy required for energy storage frequency regulation in order to determine the energy storage switching action. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention proposes a frequency regulation control method for an energy storage system taking into account the random fluctuations of renewable energy. The method can calculate an incremental control method for an energy storage frequency regulation coefficient containing random fluctuations of renewable energy and an incremental control method for an energy storage energy of a power system frequency response model containing random fluctuations of renewable energy.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A frequency modulation control method for an energy storage system taking into account random fluctuations of new energy sources comprises the following steps:

[0007] Step 1: Establish a power system frequency response model taking energy storage into account;

[0008] Step 2 calculates the energy storage frequency regulation coefficient requirement under load disturbance;

[0009] Step 3 calculates the incremental demand for energy storage frequency regulation coefficient including random fluctuations of new energy sources;

[0010] Step 4 considers the energy storage frequency regulation coefficient requirement under the load disturbance, and calculates the frequency regulation energy requirement of the energy storage system of the power system frequency response model under the load disturbance;

[0011] Step 5 calculates the energy storage increment of the power system frequency response model containing random fluctuations of new energy.

[0012] Optionally, the step of establishing a power system frequency response model taking energy storage into account specifically comprises the following steps:

[0013] A power system frequency response model including synchronous generator set speed regulator, turbine, generator and load is established; secondly, an energy storage frequency regulation loop is added to the power system frequency response model to establish a power system frequency response model taking energy storage into account.

[0014] Optionally, the method for calculating the energy storage frequency regulation coefficient requirement under load disturbance comprises the following steps:

[0015] Based on different load disturbance levels, the energy storage frequency regulation coefficient demand considering the frequency deviation limit constraint is calculated; then based on different load disturbance levels, the energy storage frequency regulation coefficient demand considering the frequency drop minimum point limit constraint is calculated; finally, the maximum value of the energy storage frequency regulation coefficient demand considering the frequency deviation limit constraint and the energy storage frequency regulation coefficient demand considering the frequency drop minimum point limit constraint is taken as the energy storage frequency regulation coefficient demand under load disturbance.

[0016] Optionally, the method for calculating the incremental energy storage frequency modulation coefficient containing random fluctuations of new energy includes the following steps:

[0017] Based on different levels of random fluctuations in renewable energy sources, the incremental demand for energy storage frequency regulation coefficient considering the frequency drop minimum point limit constraint and the incremental demand for energy storage frequency regulation coefficient considering the frequency deviation limit constraint are calculated; the incremental demand for energy storage frequency regulation coefficient is added to the energy storage frequency regulation demand, and the maximum value of the sum is taken as the energy storage frequency regulation coefficient demand under renewable energy fluctuations.

[0018] Optionally, the formula for calculating the energy storage frequency regulation coefficient requirement considering the frequency deviation limit constraint is:

[0019]

[0020] Where Δf ∞ is the frequency deviation limit, ΔP s is the load disturbance, D is the load active frequency response coefficient, K m is the frequency regulation capacity coefficient of the system synchronous unit, 1 / R is the speed regulator gain, K B represents the energy storage frequency regulation coefficient under load disturbance, R B is the energy storage adjustment coefficient; by inverse solution K B , the energy storage frequency regulation coefficient requirement K considering the frequency deviation limit constraint under load disturbance is obtained B∞ .

[0021] Optionally, the method for calculating the energy storage frequency regulation coefficient requirement considering the frequency drop minimum point limit constraint comprises the following steps:

[0022]

[0023] Where Δf m is the frequency drop minimum limit, ΔPs is the load disturbance, T R is the turbine equivalent inertia time constant, K B represents the energy storage frequency regulation coefficient under load disturbance;

[0024] A is:

[0025]

[0026] a, b, a0 are:

[0027]

[0028] Where ξ is the damping ratio, ω n is the natural frequency:

[0029]

[0030] Where M is the generator rotor inertia time constant, F H is the turbine characteristic coefficient, K B represents the energy storage frequency modulation coefficient under load disturbance; by inverse solution K B , the energy storage frequency regulation coefficient requirement K considering the frequency deviation limit constraint under load disturbance is obtained Bm .

[0031] Optionally, the method for calculating the energy storage frequency regulation coefficient requirement increment considering the frequency drop minimum point limit constraint comprises the following steps:

[0032]

[0033] Among them, ΔK Bm The incremental demand for energy storage frequency regulation factor considering the frequency drop minimum limit, ΔP add is the sum of the new energy fluctuation power and the load disturbance power, Δf m is the frequency drop minimum limit, M is the generator rotor inertia time constant. n The energy storage frequency regulation coefficient K is used in the calculation under load disturbance considering the frequency drop minimum limit constraint. B1 , and K B1 =max(K B∞ ,K Bm );ΔK B∞ The incremental demand for energy storage frequency regulation factor considering the frequency deviation limit constraint;

[0034] B is:

[0035]

[0036] C is:

[0037]

[0038] Optionally, the method for calculating the energy storage frequency regulation coefficient requirement considering the frequency deviation limit constraint comprises the following steps:

[0039]

[0040] Among them, ΔK B∞ The incremental demand for energy storage frequency regulation factor considering the frequency deviation limit constraint, ΔP new It is the power fluctuation value of new energy.

[0041] Optionally, the method for calculating the frequency regulation energy demand of the energy storage system in the power system frequency response model under load disturbance comprises the following steps:

[0042]

[0043] Among them, E e K is the energy required for energy storage under load disturbance, B represents the energy storage frequency regulation coefficient under load disturbance and substitutes the actual value K obtained in the above calculation into the calculation B1 , t a is the energy storage operation time, and t0 is the time when the load disturbance occurs.

[0044] Optionally, the method for calculating the required increment of energy storage energy of the power system frequency response model containing random fluctuations of new energy sources comprises the following steps:

[0045]

[0046] Among them, ΔE is the difference between the energy required for energy storage when new energy fluctuates randomly and the energy required for energy storage when only load disturbance is affected, ΔP new is the power fluctuation value of new energy, K B represents the energy storage frequency regulation coefficient under load disturbance and substitutes the actual value K obtained in the above calculation into the calculation B1 , t a is the energy storage operation time, and t1 is the time when the new energy fluctuation occurs. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The present invention will be further described below in conjunction with the accompanying drawings.

[0048] Figure 1 This is a flow chart of the frequency regulation control method of the energy storage system taking into account the random fluctuation of new energy sources in this application;

[0049] Figure 2 A diagram of a frequency response model of a power system taking energy storage into account in this application;

[0050] Figure 3This is the frequency change of the power system when there is only load disturbance and the energy storage frequency regulation coefficient remains unchanged in Example 1 of the present application;

[0051] Figure 4 This is the frequency change of the power system when there is load disturbance and new energy fluctuation and the energy storage frequency regulation coefficient remains unchanged in Example 1 of the present application;

[0052] Figure 5 The frequency change of the power system in the case where there is load disturbance and new energy fluctuation and the energy storage frequency regulation coefficient is updated in Example 1 of the present application;

[0053] Figure 6 This is the frequency change of the power system when there is only load disturbance and the energy storage frequency regulation coefficient remains unchanged in Example 2 of the present application;

[0054] Figure 7 This is the frequency change of the power system when there is load disturbance and new energy fluctuation and the energy storage frequency regulation coefficient remains unchanged in Example 2 of the present application;

[0055] Figure 8 This is the frequency change of the power system in Example 2 of the present application when there is load disturbance and new energy fluctuation and the energy storage frequency regulation coefficient is updated. DETAILED DESCRIPTION

[0056] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0057] Example 1

[0058] like Figure 1 This embodiment discloses a frequency control method for an energy storage system taking into account random fluctuations of new energy sources, the method comprising the following steps:

[0059] Step 1: Establish a power system frequency response model taking energy storage into account.

[0060] Firstly, a power system frequency response model including synchronous generator set speed regulator, turbine, generator and load is established. Secondly, an energy storage frequency regulation loop is added to the basic power system frequency response model to establish a power system frequency response model taking energy storage into account.

[0061] Step 2: Calculate the energy storage frequency regulation coefficient requirement under load disturbance.

[0062] First, based on different load disturbance levels, the energy storage frequency regulation coefficient demand considering the frequency deviation limit constraint is calculated; then, based on different load disturbance levels, the energy storage frequency regulation coefficient demand considering the frequency drop minimum point limit constraint is calculated; finally, the maximum value of the energy storage frequency regulation coefficient demand considering the frequency deviation limit constraint and the energy storage frequency regulation coefficient demand considering the frequency drop minimum point limit constraint is taken as the energy storage frequency regulation coefficient demand under load disturbance.

[0063] The formula for calculating the energy storage frequency regulation coefficient requirement considering the frequency deviation limit constraint based on different load disturbance levels is:

[0064]

[0065] Where Δf ∞ is the frequency deviation limit, ΔP s is the load disturbance, D is the load active frequency response coefficient, K m is the frequency regulation capacity coefficient of the system synchronous unit, 1 / R is the speed regulator gain, K B represents the energy storage frequency regulation coefficient under load disturbance, R B is the energy storage adjustment coefficient. By inversely solving K B , the energy storage frequency regulation coefficient requirement considering the frequency deviation limit constraint under load disturbance is recorded as K B∞ .

[0066] The formula for calculating the energy storage frequency regulation coefficient requirement based on different load disturbance levels and considering the frequency drop minimum limit constraint is:

[0067]

[0068] Where Δf m is the frequency drop minimum limit, ΔP s is the load disturbance, T R is the equivalent inertia time constant of the turbine, D is the load active frequency response coefficient, K B represents the energy storage frequency regulation coefficient under load disturbance, R B is the energy storage adjustment coefficient, K m is the adjustable frequency capacity coefficient of the system synchronous unit, and 1 / R is the speed regulator gain.

[0069] A is:

[0070]

[0071] a, b, a0 are:

[0072]

[0073] Where ξ is the damping ratio, ω n is the natural frequency:

[0074]

[0075] Where M is the generator rotor inertia time constant, F H is the turbine characteristic coefficient, K B represents the energy storage frequency modulation coefficient under load disturbance. By inversely solving K B , the energy storage frequency regulation coefficient requirement considering the frequency deviation limit constraint under load disturbance is obtained and recorded as K Bm .

[0076] The above formula can be solved by fitting method to obtain K Bm , where the fitting formula for calculating the energy storage frequency modulation coefficient according to the lowest point of frequency drop is:

[0077] K Bm =9.0462×10 -6 ×ΔP s 3 -2.8882×10 -4 ×ΔP s 2 +0.0239×ΔP s -0.1022

[0078] Step 3, calculate the incremental demand for energy storage frequency regulation coefficient including random fluctuations of new energy.

[0079] Firstly, based on different levels of random fluctuation of renewable energy, the incremental demand for energy storage frequency regulation coefficient considering the limit constraint of the lowest frequency drop point is calculated; secondly, based on different levels of random fluctuation of renewable energy, the incremental demand for energy storage frequency regulation coefficient considering the limit constraint of frequency deviation is calculated; finally, the incremental demand for energy storage frequency regulation coefficient obtained above is added to the energy storage frequency regulation demand under each load disturbance, and the maximum value of the sum is taken as the demand for energy storage frequency regulation coefficient under renewable energy fluctuation.

[0080] The formula for calculating the incremental demand for energy storage frequency regulation factor considering the frequency drop minimum limit constraint is:

[0081]

[0082] Among them, ΔK Bm The incremental demand for energy storage frequency regulation factor considering the frequency drop minimum limit, ΔP add is the sum of the new energy fluctuation power and the load disturbance power, Δf m is the frequency drop minimum limit, M is the generator rotor inertia time constant. n The energy storage frequency regulation coefficient considering the frequency drop minimum limit under load disturbance is denoted as K B1 , and K B1 =max(K B∞ ,KBm );

[0083] B is:

[0084]

[0085] C is:

[0086]

[0087] The formula for calculating the energy storage frequency regulation coefficient requirement considering the frequency deviation limit constraint is:

[0088]

[0089] Among them, ΔK B∞ The incremental demand for energy storage frequency regulation factor considering the frequency deviation limit constraint, ΔP new It is the power fluctuation value of new energy.

[0090] Step 4: Considering the energy storage frequency regulation coefficient requirement under the load disturbance, the frequency regulation energy requirement of the energy storage system of the power system frequency response model under the load disturbance is calculated.

[0091] The formula for calculating the frequency regulation energy demand of the energy storage system in the power system frequency response model under load disturbance is:

[0092]

[0093] Among them, E e K is the energy required for energy storage under load disturbance, B represents the energy storage frequency regulation coefficient under load disturbance and substitutes the actual value K obtained in the above calculation into the calculation B1 , t a is the energy storage operation time, and t0 is the time when the load disturbance occurs.

[0094] Step 5, calculate the energy increment required for energy storage in the power system frequency response model containing random fluctuations of new energy.

[0095] The formula for calculating the energy storage energy increment control method of the power system frequency response model containing random fluctuations of new energy is:

[0096]

[0097] Among them, ΔE is the difference between the energy required for energy storage when new energy fluctuates randomly and the energy required for energy storage when only load disturbance is affected, ΔP new is the power fluctuation value of new energy, K B represents the energy storage frequency regulation coefficient under load disturbance and substitutes the actual value K obtained in the above calculation into the calculation B1 , t ais the energy storage operation time, and t1 is the time when the new energy fluctuation occurs.

[0098] This embodiment uses a total system power of 100kW, a load disturbance of 10kW, a new energy fluctuation of 1kW, a load disturbance occurring at 1s, a new energy fluctuation occurring at 2s, and energy storage participating in frequency modulation for 200s. The frequency drop minimum point limit is set to 0.5Hz, and the frequency deviation limit is set to 0.2Hz. The relevant parameter settings are as follows:

[0099] D=1,K m =0.95, R =0.05, R B =0.01, M = 6.7, T R =8, F H =0.3, T B =0.01.

[0100] The energy storage frequency regulation coefficient K is calculated based on the frequency deviation and the frequency drop minimum limit under different load disturbances. B1 =0.3; perform curve fitting according to the frequency drop lowest point calculation formula to calculate the energy storage frequency modulation coefficient K B2 =0.1168; take the maximum value K B3 =max(K B1 ,K B2 )=0.3.

[0101] The energy storage frequency regulation coefficient requirements under different new energy fluctuations are calculated based on the frequency deviation and the frequency drop minimum limit. The energy storage frequency regulation coefficient ΔK is calculated according to the frequency deviation formula B-new1 =0.05; Calculate the energy storage frequency modulation coefficient ΔK according to the formula of the lowest frequency drop point B-new2 =0.088; therefore, according to the frequency deviation, the energy storage frequency regulation coefficient under the fluctuation of new energy is K B-new1 =0.35; according to the lowest point of frequency drop, the energy storage frequency regulation coefficient under the fluctuation of new energy is obtained as K B-new2 =0.2048; take the maximum value K B-new3 =max(K B-new1 ,K B-new2 )=0.35.

[0102] According to the formula, the frequency response model of the power system under load disturbance can be used to calculate the frequency regulation energy demand of the energy storage system, and E e1 =0.335kWh.

[0103] According to the formula, the frequency response model of the power system under the fluctuation of new energy sources is used to calculate the frequency regulation energy demand of the energy storage system, and ΔE is obtained. new 1=0.0353kWh, adding them together, we can get the energy storage demand under the fluctuation of new energy as E new 1=0.3703kWh.

[0104] When there is only load disturbance, the energy storage frequency regulation coefficient is K B3 When the energy storage action is activated, the system frequency change curve is as follows: Figure 3 It can be observed that the load begins to disturb at 1 second, and the frequency begins to fluctuate accordingly. The minimum value of the frequency drop does not exceed 0.5Hz, and the maximum value of the frequency deviation is controlled at 0.2Hz.

[0105] When new energy fluctuations are added, but the energy storage frequency modulation coefficient remains unchanged, the system frequency change curve after the energy storage action is as follows: Figure 4 It can be observed that the new energy begins to fluctuate at 2s. Although the minimum frequency drop does not exceed 0.5Hz, the maximum frequency deviation exceeds 0.2Hz.

[0106] When new energy fluctuations are added, the energy storage frequency modulation coefficient becomes K B-new3 When the energy storage action is activated, the system frequency change curve is as follows: Figure 5 At this time, the maximum frequency deviation is controlled at 0.2Hz.

[0107] Example 2

[0108] This embodiment uses a total system power of 100kW, a load disturbance of -8kW, a new energy fluctuation of -0.5kW, a load disturbance occurring at 1s, a new energy fluctuation occurring at 2s, and energy storage participating in frequency modulation for 200s. The frequency drop minimum point limit is set to 0.5Hz, and the frequency deviation limit is set to 0.2Hz. The relevant parameter settings are as follows:

[0109] D=1,K m =0.95, R =0.05, R B =0.01, M = 6.7, T R =8, F H =0.3, T B =0.01.

[0110] The energy storage frequency regulation coefficient K is calculated based on the frequency deviation and the frequency drop minimum limit under different load disturbances. B1 =0.2; perform curve fitting according to the frequency drop lowest point calculation formula to calculate the energy storage frequency modulation coefficient K B2 =0.075; take the maximum value K B3 =max(K B1 ,K B2 )=0.2.

[0111] The energy storage frequency regulation coefficient requirements under different new energy fluctuations are calculated based on the frequency deviation and the frequency drop minimum limit. The energy storage frequency regulation coefficient ΔK is calculated according to the frequency deviation formula B-new1=0.025; Calculate the energy storage frequency modulation coefficient ΔK according to the formula of the lowest frequency drop point B-new2 =0.0441; therefore, according to the frequency deviation, the energy storage frequency regulation coefficient under the fluctuation of new energy is K B-new1 =0.225; according to the lowest point of frequency drop, the energy storage frequency regulation coefficient under the fluctuation of new energy is obtained as K B-new 2 = 0.1191; take the maximum value K B-new3 =max(K B-new1 ,K B-new2 )=0.225.

[0112] According to the formula, the frequency response model of the power system under load disturbance can be used to calculate the frequency regulation energy demand of the energy storage system, and E e1 =0.2239kWh.

[0113] According to the formula, the frequency response model of the power system under the fluctuation of new energy sources is used to calculate the frequency regulation energy demand of the energy storage system, and ΔE is obtained. new 1=0.0147kWh, adding them together, we can get the energy storage demand under the fluctuation of new energy as E new1 =0.2386kWh.

[0114] When there is only load disturbance, the energy storage frequency regulation coefficient is K B3 When the energy storage action is activated, the system frequency change curve is as follows: Figure 6 It can be observed that the load begins to disturb at 1 second, and the frequency begins to fluctuate accordingly. The minimum value of the frequency drop does not exceed 0.5Hz, and the maximum value of the frequency deviation is controlled at 0.2Hz.

[0115] When new energy fluctuations are added, but the energy storage frequency modulation coefficient remains unchanged, the system frequency change curve after the energy storage action is as follows: Figure 7 It can be observed that the new energy begins to fluctuate at 2s. Although the minimum frequency drop does not exceed 0.5Hz, the maximum frequency deviation exceeds 0.2Hz.

[0116] When new energy fluctuations are added, the energy storage frequency modulation coefficient becomes K B-new3 When the energy storage action is activated, the system frequency change curve is as follows: Figure 8 At this time, the maximum frequency deviation is controlled at 0.2Hz.

[0117] In summary, the above formula can be used to calculate the frequency control of energy storage systems taking into account random fluctuations of new energy more quickly and effectively.

[0118] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0119] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A frequency control method for an energy storage system taking into account random fluctuations of new energy, characterized in that: The following steps are involved: Step 1: Establish a power system frequency response model taking energy storage into account; Step 2 calculates the energy storage frequency regulation coefficient requirement under load disturbance; Step 3 calculates the incremental demand for energy storage frequency regulation coefficient including random fluctuations of new energy sources; Step 4 considers the energy storage frequency regulation coefficient requirement under the load disturbance, and calculates the frequency regulation energy requirement of the energy storage system of the power system frequency response model under the load disturbance; Step 5 calculates the energy increment required for energy storage of the power system frequency response model containing random fluctuations of new energy sources; The establishment of the power system frequency response model taking into account energy storage specifically includes the following steps: A power system frequency response model including synchronous generator set speed regulator, turbine, generator and load is established; secondly, an energy storage frequency regulation loop is added to the power system frequency response model to establish a power system frequency response model taking energy storage into account.

2. The frequency modulation control method of energy storage system taking into account random fluctuations of new energy according to claim 1 is characterized in that: The method for calculating the energy storage frequency regulation coefficient requirement under load disturbance comprises the following steps: Based on different load disturbance levels, the energy storage frequency regulation coefficient demand considering the frequency deviation limit constraint is calculated; then based on different load disturbance levels, the energy storage frequency regulation coefficient demand considering the frequency drop minimum point limit constraint is calculated; finally, the maximum value of the energy storage frequency regulation coefficient demand considering the frequency deviation limit constraint and the energy storage frequency regulation coefficient demand considering the frequency drop minimum point limit constraint is taken as the energy storage frequency regulation coefficient demand under load disturbance.

3. The frequency modulation control method of energy storage system taking into account random fluctuations of new energy according to claim 1 is characterized in that: The method for calculating the incremental demand for energy storage frequency modulation coefficient with random fluctuations of new energy sources comprises the following steps: Based on different levels of random fluctuations in renewable energy sources, the incremental demand for energy storage frequency regulation coefficient considering the frequency drop minimum point limit constraint and the incremental demand for energy storage frequency regulation coefficient considering the frequency deviation limit constraint are calculated; the incremental demand for energy storage frequency regulation coefficient and the demand for energy storage frequency regulation coefficient are added together respectively, and the maximum value of the sum is taken as the demand for energy storage frequency regulation coefficient under renewable energy fluctuations.

4. The frequency modulation control method of energy storage system taking into account random fluctuations of new energy according to claim 2 is characterized in that: The formula for calculating the energy storage frequency regulation coefficient requirement considering the frequency deviation limit constraint is: Where Δf ∞ is the frequency deviation limit, ΔP s is the load disturbance, D is the load active frequency response coefficient, K m is the frequency regulation capacity coefficient of the system synchronous unit, 1 / R is the speed regulator gain, K B represents the energy storage frequency regulation coefficient under load disturbance, R B is the energy storage adjustment coefficient; by inverse solution K B , the energy storage frequency regulation coefficient requirement K considering the frequency deviation limit constraint under load disturbance is obtained B∞ .

5. The frequency modulation control method of energy storage system taking into account random fluctuations of new energy according to claim 2 is characterized in that: The method for calculating the energy storage frequency regulation coefficient requirement considering the frequency drop minimum point limit constraint comprises the following steps: Where Δf m is the frequency drop minimum limit, ΔP s is the load disturbance, T R is the turbine equivalent inertia time constant, K B represents the energy storage frequency regulation coefficient under load disturbance; A is: a, b, a0 are: Where ξ is the damping ratio, ω n is the natural frequency: Where M is the generator rotor inertia time constant, F H is the turbine characteristic factor, K B represents the energy storage frequency modulation coefficient under load disturbance; by inverse solution K B , and obtain the energy storage frequency regulation coefficient requirement K under load disturbance considering the frequency deviation limit constraint Bm .

6. The frequency modulation control method of energy storage system taking into account random fluctuations of new energy according to claim 3 is characterized in that: The method for calculating the incremental demand for energy storage frequency regulation coefficient considering the frequency drop minimum point limit constraint comprises the following steps: Among them, ΔK Bm The incremental demand for energy storage frequency regulation factor considering the frequency drop minimum limit, ΔP add is the sum of the new energy fluctuation power and the load disturbance power, Δf m is the frequency drop minimum limit, M is the generator rotor inertia time constant; where A and ω n The energy storage frequency regulation coefficient K is used in the calculation under load disturbance considering the frequency drop minimum limit constraint. B1 , and K B1 =max(K B∞ ,K Bm );ΔK B∞ The incremental demand for energy storage frequency regulation factor considering the frequency deviation limit constraint; B is: C is:

7. The frequency modulation control method of energy storage system taking into account random fluctuations of new energy according to claim 3 is characterized in that: The method for calculating the incremental demand for energy storage frequency regulation coefficient considering the frequency deviation limit constraint comprises the following steps: Among them, ΔK B∞ The incremental demand for energy storage frequency regulation factor considering the frequency deviation limit constraint, ΔP new It is the power fluctuation value of new energy.

8. The frequency modulation control method of energy storage system taking into account random fluctuations of new energy according to claim 1, characterized in that: The method for calculating the frequency regulation energy demand of the energy storage system of the power system frequency response model under load disturbance comprises the following steps: Among them, E e K is the energy required for energy storage under load disturbance, B represents the energy storage frequency regulation coefficient under load disturbance and substitutes the actual value K obtained in the above calculation into the calculation B1 , t a is the energy storage operation time, and t0 is the time when the load disturbance occurs.

9. The frequency modulation control method of energy storage system taking into account random fluctuations of new energy according to claim 1, characterized in that: The method for calculating the energy increment required for energy storage in the power system frequency response model containing random fluctuations of new energy sources comprises the following steps: Among them, ΔE is the difference between the energy required for energy storage when new energy fluctuates randomly and the energy required for energy storage when only load disturbance is affected, ΔP new is the power fluctuation value of new energy, K B It represents the energy storage frequency regulation coefficient under load disturbance, and the actual value obtained in the calculation is recorded as K B1 , t a is the energy storage operation time, and t1 is the time when the new energy fluctuation occurs.

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