New energy storage configuration method based on frequency response

Abstract

The invention discloses a new energy storage configuration method based on frequency response, and the method comprises the steps: obtaining the maximum power increment [delta] Pxh and [delta] Pxk under the constraint of a frequency change rate and the limitation of frequency deviation according to a three-order model of a virtual synchronous machine, and extracting the actual maximum power increment [delta] Pxm; on the basis of the delta Pxh and the delta Pxk, acquiring renewable new energy ratio thresholds xih and xik of the power system under the constraint of the frequency change rate and the constraint of the frequency deviation, and marking the smaller value as a renewable new energy ratio threshold xib; the energy storage system participates in frequency modulation of the power system, and the minimum power capacity PESS needing to be supplemented by the energy storage system under the limitation of frequency deviation is obtained; configuring parameters of the energy storage system according to the delta Pxh, the delta Pxk and the xi b; judging whether the minimum power capacity PESS is within the required threshold value of the frequency change rate met by the delta Pxm or not; if yes, inertia configuration is completed; if not, parameter adjustment is carried out, and judgment is carried out again. The method relates to the field of new energy, and solves the technical problem of unreasonable capacity configuration in an existing energy storage configuration method.

Description

Technical Field

[0001] The present invention belongs to the field of new energy and power systems, and relates to energy storage configuration technology, specifically a new energy storage configuration method based on frequency response. Background Art

[0002] Renewable energy generation is random, intermittent and volatile. Its large-scale grid connection will cause grid frequency fluctuations, thus affecting the stability and security of the power system. As a bridge connecting renewable energy generation and the power grid, energy storage technology plays an indispensable role in ensuring the balance of power supply and demand, improving system flexibility and improving the stability of renewable energy grid connection. By absorbing and releasing energy, the energy storage system can effectively alleviate the intermittent and volatile nature of renewable energy generation, provide the grid with the necessary regulation capabilities and spare capacity, and ensure the safe and stable operation of the power system.

[0003] However, current new energy storage configuration methods often only focus on simple power shortages or system backup capacity, ignoring the specific response requirements of the power system under different frequency change rates and frequency deviations. Therefore, the existing energy storage configuration methods have unreasonable problems and cannot comprehensively evaluate the performance of the energy storage system under extreme conditions, which can easily lead to the energy storage system being unable to provide sufficient support at certain critical moments, thereby affecting the stable operation of the power grid. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art; to this end, the present invention proposes a new energy storage configuration method based on frequency response, which is used to solve the technical problem of unreasonable capacity configuration in the existing energy storage configuration method.

[0005] To achieve the above object, the present invention provides a new energy storage configuration method based on frequency response, comprising:

[0006] S1, establish a virtual synchronous machine third-order model, and obtain the maximum power increment ΔP under the frequency change rate constraint according to the virtual synchronous machine third-order model xh Maximum power increment ΔP under frequency deviation limit xk , and extract the actual maximum power increment ΔP from the power system operation data xm ;

[0007] S2, based on the ΔP xh and the ΔP xk Obtain the renewable energy proportion threshold ξ of the power system under the frequency change rate constraint h , and the renewable energy share threshold ξ of the power system under the frequency deviation constraint k , will h and kThe minimum value in is marked as the renewable energy proportion threshold ξ under the system frequency response b ;

[0008] S3, construct a control framework for the energy storage system, use the energy storage system to participate in the frequency regulation of the power system, and obtain the minimum power capacity P that the energy storage system needs to supplement under the frequency deviation limit. ESS ;

[0009] S4, according to the ΔP xh , the ΔP xk and the b , configuring parameters of the energy storage system;

[0010] S5, determining the minimum power capacity P ESS Whether the ΔP xm The frequency change rate requirement threshold is met; if yes, the inertial configuration is completed to obtain a configured energy storage system; if no, according to the ΔP xh With the ΔP xm For the minimum power capacity P ESS Adjust and determine again whether the power capacity is within the ΔP xm The frequency change rate requirement threshold is met.

[0011] Based on the above technical solutions, the optimization of new energy storage configuration is achieved. By constructing a third-order model of a virtual synchronous machine, the whole process of the energy storage system participating in frequency regulation is simulated; the maximum power increment under the constraints of frequency change rate and frequency deviation is obtained, and the maximum power increment in the actual operation data is extracted to determine the maximum power deviation that the system can withstand, as well as the threshold of renewable energy proportion under this condition, ensuring that the penetration rate of new energy is within a reasonable range; by designing the overall control strategy of the energy storage system and simulating the frequency regulation characteristics of the synchronous generator, the energy storage system can automatically share the imbalance rate in actual operation, providing effective frequency regulation support for the energy storage system; based on the maximum power increment and the threshold of new energy proportion, the energy storage system parameters are configured to ensure that the energy storage system not only meets the frequency response requirements of the system, but also has good operating efficiency.

[0012] Furthermore, the maximum power increment ΔP under the frequency change rate constraint is obtained according to the virtual synchronous machine third-order model. xh Maximum power increment ΔP under frequency deviation limit xk ,include:

[0013] A1, according to the equivalent inertia constant and the second-order rotor motion equation of the virtual synchronous machine third-order model, the relationship equation among the frequency change rate, the power increment and the equivalent inertia constant is obtained;

[0014] A2, based on the relationship equation and the known frequency change rate of the power system Solve to obtain the maximum power increment ΔP under the frequency change rate constraint xh for: Among them, S x represents the total installed capacity of the power system, H i represents the i-th equivalent inertia constant, represents the frequency change rate of the power system, f 0 represents the initial frequency, ξ h It represents the threshold value of renewable energy proportion under the frequency change rate constraint;

[0015] A3, based on the relationship equation and the known frequency unit change Δf, solve to obtain the maximum power increment ΔP under the frequency deviation limit xk for: Among them, σ i represents the regulation coefficient of the i-th synchronous generator, ξ k It represents the threshold value of renewable energy proportion in the power system under the frequency deviation constraint.

[0016] In the optimization of energy storage system configuration, the maximum power increment under the frequency change rate constraint and the maximum power increment under the frequency deviation rate constraint represent the maximum power fluctuation that the power system can withstand under different frequency changes. These two constraints jointly determine the power capacity that the energy storage system needs to supplement to ensure that the power system can operate stably in the face of fluctuations in renewable energy output and load changes. If only one of the constraints is considered, the configured energy storage capacity will not be able to meet the needs of the power system in the case of drastic frequency changes or continuous large deviations, and it is easy to cause waste or insufficient energy storage capacity, thereby increasing unnecessary investment costs or the overall economy of the system.

[0017] Furthermore, the ΔP xh and ΔP xk Obtain the renewable energy proportion threshold ξ of the power system under the frequency change rate constraint h and the renewable energy share threshold ξ of the power system under the frequency deviation constraint k ,include:

[0018] According to the maximum power increment ΔP under the frequency change rate constraint xh The expression is: Get ξ h for:

[0019] According to the maximum power increment ΔP under the frequency deviation limit xk The expression is: Get ξ k for:

[0020] Based on the frequency response characteristics of the power system, the threshold values ​​of the proportion of renewable energy under the frequency change rate constraint and the frequency deviation constraint are calculated respectively to guide the planning and scheduling of the power system. This ensures that the power system can still maintain a stable operating frequency under the condition of high penetration of new energy, avoids frequency instability caused by fluctuations in new energy output, and helps to improve the robustness and reliability of the power system and reduce the operational risks brought by the access of new energy.

[0021] Furthermore, the control framework of the energy storage system includes: a voltage measurement module, a current measurement module, a power calculation module, a virtual speed control system module, a virtual excitation system module, a virtual synchronous generator module, a virtual impedance module, an inverter module, an output voltage module and a battery module; wherein,

[0022] The voltage measurement module is used to measure the voltage at the busbar to which the energy storage power station is directly connected;

[0023] The current measurement module is used to measure the current at the busbar to which the energy storage power station is directly connected;

[0024] The power calculation module is used to convert the measured voltage and current into power through a formula;

[0025] The virtual speed regulation system module is used to simulate the frequency regulation principle of the speed regulation system of the synchronous generator and to distribute the unbalanced power;

[0026] Virtual excitation system module, which simulates the excitation system of synchronous generator for voltage regulation;

[0027] Virtual synchronous generator module, used to simulate the external characteristics of synchronous generator, control the inverter and increase inertia;

[0028] Virtual impedance module, used to prevent large current from flowing into the inverter and causing damage to the inverter;

[0029] Inverter module, used to convert direct current into alternating current;

[0030] An output voltage module is used to process the real and imaginary parts of the voltage flowing into the module, as well as the voltage amplitude parameters, and output a current that meets the inverter constraint conditions;

[0031] The battery module includes: a unit battery module, an AC current module and a PQ measurement module; wherein the unit battery module is used to convert the current unit into the battery capacity unit; the AC current module is used to solve the AC current; and the PQ measurement module is used to measure the active power and reactive power at the busbar directly connected to the energy storage power station.

[0032] Based on the control framework of the above energy storage system, each module works together to simulate the characteristics of the synchronous generator and effectively support the power system, realizing the process of energy storage system participating in the frequency regulation of the power system, improving the system's energy utilization and absorption capacity, and ensuring the stability and reliability of the power system.

[0033] Furthermore, the minimum power capacity P that the energy storage system needs to supplement under the frequency deviation limit is obtained. ESS The calculation formula is: ESS =ΔP xm -ΔP xk .

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] The third-order model of the virtual synchronous machine is used to simulate the entire process of the energy storage system participating in frequency regulation, and the maximum power increment of the power system under the constraints of the frequency change rate and frequency deviation is obtained. The maximum power increment of the actual operation of the power system is taken into account to ensure that the capacity configuration of the energy storage system not only meets the frequency regulation requirements but also has good economy. The threshold value of the proportion of new energy is obtained by further calculation to guide the planning and scheduling of the power system capacity, and also ensure that the access of new energy will not exceed the stable bearing capacity of the power system, thereby reducing the operating risk of the power system due to the access of new energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 A schematic diagram of a flow chart of a new energy storage configuration method based on frequency response provided by the present invention;

[0038] Figure 2 A system frequency waveform diagram when no energy storage is configured provided by an embodiment of the present invention;

[0039] Figure 3 A system voltage waveform diagram when no energy storage is configured provided by an embodiment of the present invention;

[0040] Figure 4 A system frequency waveform diagram after energy storage is configured according to an embodiment of the present invention;

[0041] Figure 5 A voltage waveform diagram of a system after energy storage is configured according to an embodiment of the present invention. DETAILED DESCRIPTION

[0042] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. 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.

[0043] See also Figure 1-Figure 5 , an embodiment of the present invention provides a new energy storage configuration method based on frequency response, comprising:

[0044] S1, establish a virtual synchronous machine third-order model, and obtain the maximum power increment ΔP under the frequency change rate constraint according to the virtual synchronous machine third-order model xh Maximum power increment ΔP under frequency deviation limit xk , and extract the actual maximum power increment ΔP from the power system operation data xm ;

[0045] S2, based on ΔP xh and ΔP xk Obtain the renewable energy proportion threshold ξ of the power system under the frequency change rate constraint h and the renewable energy share threshold ξ of the power system under the frequency deviation constraint k , will h and k The minimum value in is marked as the renewable energy proportion threshold ξ under the system frequency response b ;

[0046] S3, construct a control framework for the energy storage system, use the energy storage system to participate in the frequency regulation of the power system, and obtain the minimum power capacity P that the energy storage system needs to supplement under the frequency deviation limit. ESS ;

[0047] S4, according to the ΔP xh , the ΔP xk and the b , configuring parameters of the energy storage system;

[0048] S5, determining the minimum power capacity P ESS Whether the ΔP xm The frequency change rate requirement threshold is met; if yes, the inertial configuration is completed to obtain a configured energy storage system; if no, according to the ΔP xh With the ΔP xm For the minimum power capacity P ESS Adjust and determine again whether the power capacity is within the ΔP xm The frequency change rate requirement threshold is met.

[0049] In this embodiment, in order to achieve the purpose of the energy storage system participating in frequency and voltage regulation, a virtual synchronous generator third-order model is established based on the second-order motion equation and the first-order transient voltage equation of the synchronous motor, and its formula is: Among them, H is the inertia constant, and its physical meaning is the ratio of the energy storage capacity of the unit rotor at the rated speed to the rated power of the motor. D is the damping coefficient of the virtual synchronous generator, ω 0 is the virtual generator angular velocity under the per-unit value, Δω is the deviation between the rated speed and the actual speed; P m is the mechanical power, which is equivalent to the mechanical torque of the synchronous generator, P e is the electromagnetic power, equivalent to the electromagnetic torque of the synchronous generator, δ is the internal potential phase angle of the synchronous machine; T' d0 Synchronous generator d-axis open circuit transient time constant, E' q is the synchronous generator q-axis transient electromotive force, also known as transient electromotive force, E qe is the forced no-load electromotive force, i d is the direct axis current component; x d is the direct-axis synchronous reactance; x' d is the direct-axis transient reactance;

[0050] The inertia constant of a synchronous machine refers to the ratio of the moment of inertia of the synchronous machine rotor to the mass of the machine body, and the unit is usually in seconds. The larger the inertia constant of a synchronous machine, the more obvious its inertia effect, the slower the speed change, and the smaller the impact on the steady-state operation of the system. In large power systems, multiple synchronous machine units are often included. In order to describe the inertia characteristics of the entire system, H is used. x To characterize the equivalent inertia constant, we have: Among them, S x represents the total installed capacity of the power system, S i represents the rated capacity of the i-th installed unit, H i represents the i-th equivalent inertia constant;

[0051] In the power system, when there is a deviation between the increase in load and the increase in system output, it will directly lead to a power increase ΔP x According to the second-order rotor motion equation of the virtual synchronous machine third-order model The frequency change rate and power increment ΔP can be established x and the equivalent inertia constant H x The relationship between: Among them, K D denotes the damping coefficients, ω and ω b represents the rotor angular frequency and its reference value, θ represents the rotor angle, f represents the frequency, represents the frequency change rate of the power system, f0 represents the initial frequency, t represents the time;

[0052] The power increment ΔP can be obtained from formula 2 and formula 4 x The expression is: Equation 5). Since the equivalent inertia constant H of each synchronous generator set i are the same, then when the frequency change rate is known, the maximum power increment ΔP under the frequency change rate constraint is xh for: (Formula 6), where ξ h It represents the threshold value of renewable energy proportion under the frequency change rate constraint. At this time, the mathematical expression containing the proportion of renewable energy can be used to reflect the maximum power increment constrained by the system frequency change rate;

[0053] Unit regulation power indicates the ability of the synchronous machine to respond to the stability of the system frequency in the power system. The larger the unit regulation power of the synchronous machine, the stronger its ability to regulate the system frequency, and the faster it can respond to frequency changes and maintain system stability. Generally speaking, for a power system containing n synchronous machine units, its equivalent unit regulation power K x for: Among them, σ i represents the regulation coefficient of the ith synchronous generator; in the primary frequency regulation of the system, assuming that the frequency regulation capacity of the synchronous machine is sufficient, the steady-state frequency deviation and the equivalent unit regulation power have the following relationship: Where Δf represents the unit change of frequency. Combining Formula 7 and Formula 8, we can solve the power increment ΔP under the constraint of frequency deviation. x for: Among them, K i is the unit adjustment power of the ith synchronous machine unit; when Δf is known, the maximum power increment that the high penetration new energy system can bear can be obtained according to Formula 9, that is, the maximum power increment ΔP under the frequency deviation limit xk for: Among them, ξ k It represents the threshold value of renewable energy proportion in the power system under the frequency deviation constraint.

[0054] According to the maximum power increment ΔP under the frequency change rate constraint xh The expression of can be transformed to obtain the threshold value of renewable energy proportion ξ of the power system under the constraint of frequency change rate h for: (Formula 11); Similarly, for ΔP xk By transforming the expression of , we can get the threshold value ξ of the proportion of renewable energy in the power system under the frequency deviation constraint condition. k for: Compare hand k The minimum value is selected as the threshold value of renewable energy proportion under the system frequency response ξ b .

[0055] In the power system, when unbalanced power is generated, the load and frequency regulation units traditionally bear the power fluctuations together. However, for high-penetration new energy units that adopt the maximum power point tracking control strategy, the situation is different. Such units need to retain a certain amount of active reserve capacity to ensure frequency regulation capability, which often leads to the waste of wind and solar energy, the so-called wind and solar abandonment. More seriously, after the frequency regulation action is completed, the system frequency may experience a secondary drop, further exacerbating the stability problem of the system. In addition, when the wind speed is low or the light is weak, the frequency regulation capacity of the new energy unit needs to be fully loaded, which cannot meet the power demand of the system, and it is impossible to reserve spare power and capacity. Therefore, under these extreme conditions, the support role of the new energy unit to the system frequency is very limited. On the other hand, although load demand adjustment can be used as a solution, it will sacrifice the user's electricity demand to a certain extent, which may cause user dissatisfaction and system operation problems.

[0056] Therefore, in order to make up for the deficiencies of renewable energy units and traditional frequency regulation units, after research and analysis, an energy storage system will be added to supplement the energy shortage without changing the output and load of the new energy power generation system, so as to provide the power, voltage and energy support required by the power system in the inertia response and primary frequency regulation stages. The overall control framework of the energy storage system in this embodiment includes: a voltage measurement module, a current measurement module, a power calculation module, a virtual speed regulation system module, a virtual excitation system module, a virtual synchronous generator module, a virtual impedance module, an inverter module, an output voltage module and a battery module; among them,

[0057] A voltage measurement module is used to measure the voltage at the busbar to which the energy storage power station is directly connected;

[0058] A current measurement module is used to measure the current at the busbar to which the energy storage power station is directly connected;

[0059] A power calculation module, used to convert the measured voltage and current into power through a formula;

[0060] Virtual speed regulation system module, used to simulate the frequency regulation principle of the speed regulation system of synchronous generators and share the unbalanced power;

[0061] The virtual excitation system module imitates the excitation system of the synchronous generator and is used for voltage regulation, which has a certain supporting effect on the grid voltage.

[0062] The virtual synchronous generator module is used to simulate the external characteristics of the synchronous generator, increase the inertia on the basis of inverter control, and increase the stability of the power system;

[0063] Virtual impedance module, used to prevent large current from flowing into the inverter and causing damage to the inverter;

[0064] Inverter module, used to convert direct current into alternating current;

[0065] The output voltage module is used to process the real and imaginary parts of the voltage flowing into the module, the voltage amplitude and other parameters, and output the current that meets the inverter constraint conditions;

[0066] The battery module includes: a unit battery module, an AC current module and a PQ measurement module; wherein the unit battery module is used to convert the current unit into the battery capacity unit; the AC current module is used to solve the AC current; and the PQ measurement module is used to measure the active power and reactive power at the busbar directly connected to the energy storage station.

[0067] In this embodiment, it is assumed that the inertia constant H is uniformly 4, the rated capacity S of the installed units is uniformly 800MW, the number of installed units n is 10, and the initial frequency f 0 The frequency change rate is 50Hz. The value is 0.5Hz / s, the maximum allowable frequency deviation is 0.2Hz, and the minimum value is substituted into Formula 6 and Formula 10 to obtain the maximum power increment that the system can withstand under the constraints of frequency deviation and frequency change rate, which is 700MW. At this time, the actual maximum power increment is 1300MW. Subtracting the two, the required capacity of the energy storage system is 600MW.

[0068] After the capacity configuration is completed, in order to ensure that the frequency change rate is not greater than 0.5Hz / s, the inertia needs to be configured to 10s. Other related parameters are set as follows: the adjustment parameter of the synchronous machine is 0.01, the charging and discharging efficiency of the energy storage is 80%, the initial state of charge of the energy storage battery is 50%, the upper limit of the state of charge is 80%, and the lower limit is 30%, that is, when the battery state of charge exceeds 80%, the energy storage will no longer charge, and when the battery state of charge is less than 30%, the energy storage will no longer discharge; and the current new energy penetration rate is set to 20%.

[0069] like Figure 2 and Figure 3 The figure shows the system frequency waveform and system voltage waveform of the power system without energy storage configuration, without considering the impact of the location of the energy storage power station on the frequency and voltage regulation of the power grid. The system frequency waveform and system voltage waveform after energy storage configuration are shown in Figure 1. Figure 4 and Figure 5 As shown; among them, Figure 2 and Figure 4The vertical axis represents the frequency value, and the horizontal axis represents the operation time of the power system. Figure 3 and Figure 5 The vertical axis represents the voltage value, and the horizontal axis represents the operation time of the power system.

[0070] According to the waveforms before and after configuration, it can be obtained that within the time range of 400s to 500s, the frequency change rate of the system is about 0.1Hz / s, which is 50% less than the previous standard frequency change rate of 0.2Hz / s; at the same time, within the time range of 400s to 500s, the steady-state frequency deviation of the power system before energy storage configuration is 49.3Hz, and the steady-state frequency deviation of the system after energy storage configuration is 49.88Hz, a total increase of about 82%. It can be seen that with the gradual increase in the penetration rate of new energy and the corresponding decrease in the proportion of thermal power units, the energy storage system has a fast response and a fast climbing rate. It can quickly assist thermal power units, reduce the number of times thermal power units frequently participate in system frequency modulation, and improve the stability of system operation. In addition, the energy storage capacity configured under the constraints of frequency deviation and frequency change rate is sufficient to cope with various extreme situations. It can not only ensure that the steady-state frequency deviation is controlled within 0.2Hz, but even 80% of the cases are controlled within 0.12Hz, and the frequency change rate is also less than 0.2Hz / s. Therefore, at this time, the minimum power capacity that the energy storage system needs to supplement under the frequency deviation limit is 600MW, which is within the frequency change rate requirement. It can be seen that the configuration method is effective and correct.

[0071] Part of the data in the above formula is calculated by removing the dimension and taking its numerical value. The formula is a formula closest to the actual situation obtained by software simulation of a large amount of collected data; the preset parameters and preset thresholds in the formula are set by technical personnel in this field according to actual conditions or obtained through simulation of a large amount of data.

[0072] Working principle of the present invention:

[0073] The present invention constructs a virtual synchronous machine third-order model that integrates the second-order rotor motion equations and first-order transient voltage equations of the synchronous generator, simulates the dynamic characteristics of the synchronous generator, and calculates the maximum power increment of the power system under different frequency change rates and frequency constraints; then, based on the frequency response requirements of the power system, determines the maximum fluctuation range that the power system can withstand under the constraints of the frequency change rate and frequency deviation, so as to obtain the minimum power capacity that the energy storage system needs to supplement; by calculating the threshold value of the proportion of renewable energy in the power system under the constraints of the frequency change rate and frequency deviation, the planning and scheduling of the power system are guided; finally, according to the above calculation results, combined with the actual operation data of the power system, the configuration of various parameters of the energy storage system is completed, thereby realizing an energy storage configuration method that is both economical and meets technical requirements.

[0074] The above embodiments are only used to illustrate the technical method of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical method of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical method of the present invention.

Claims

1. A new energy storage configuration method based on frequency response, characterized in that: include: S1, establish a virtual synchronous machine third-order model, and obtain the maximum power increment ΔP under the frequency change rate constraint according to the virtual synchronous machine third-order model xh Maximum power increment ΔP under frequency deviation limit xk , and extract the actual maximum power increment ΔP from the power system operation data xm ; S2, based on the ΔP xh and the ΔP xk Obtain the renewable energy proportion threshold ξ of the power system under the frequency change rate constraint and frequency deviation constraint respectively h and the renewable energy share threshold ξ k , will h and k The minimum value in is marked as the renewable energy proportion threshold ξ under the system frequency response b ; S3, construct a control framework for the energy storage system, use the energy storage system to participate in the frequency regulation of the power system, and obtain the minimum power capacity P that the energy storage system needs to supplement under the frequency deviation limit. ESS ; S4, according to the ΔP xh , the ΔP xk and the b , configuring parameters of the energy storage system; S5, determining the minimum power capacity P ESS Whether the ΔP xm The frequency change rate requirement threshold is met; if yes, the inertial configuration is completed to obtain a configured energy storage system; if no, according to the ΔP xh With the ΔP xm For the minimum power capacity P ESS Make adjustments and repeat S5.

2. A new energy storage configuration method based on frequency response according to claim 1, characterized in that: According to the virtual synchronous machine third-order model, the maximum power increment ΔP under the frequency change rate constraint is obtained xh Maximum power increment ΔP under frequency deviation limit xk ,include: A1, according to the equivalent inertia constant and the second-order rotor motion equation of the virtual synchronous machine third-order model, the relationship equation among the frequency change rate, the power increment and the equivalent inertia constant is obtained; A2, based on the relationship equation and the known frequency change rate of the power system Solve to obtain the maximum power increment ΔP under the frequency change rate constraint xh for: Among them, S x represents the total installed capacity of the power system, H i represents the i-th equivalent inertia constant, represents the frequency change rate of the power system, f0 represents the initial frequency, ξ h It represents the threshold value of renewable energy proportion under the frequency change rate constraint; A3, based on the relationship equation and the known frequency unit change Δf, solve to obtain the maximum power increment ΔP under the frequency deviation limit xk for: Among them, σ i represents the regulation coefficient of the i-th synchronous generator, ξ k It represents the threshold value of renewable energy proportion in the power system under the frequency deviation constraint.

3. A new energy storage configuration method based on frequency response according to claim 1, characterized in that: Based on the ΔP xh and the ΔP xk Obtain the renewable energy proportion threshold ξ of the power system under the frequency change rate constraint and frequency deviation constraint respectively h and the renewable energy share threshold ξ k ,include: According to the maximum power increment ΔP under the frequency change rate constraint xh The expression is: Get ξ h for: According to the maximum power increment ΔP under the frequency deviation limit xk The expression is: Get ξ k for:

4. A new energy storage configuration method based on frequency response according to claim 1, characterized in that: The control framework of the energy storage system includes: a voltage measurement module, a current measurement module, a power calculation module, a virtual speed regulation system module, a virtual excitation system module, a virtual synchronous generator module, a virtual impedance module, an inverter module, an output voltage module and a battery module; wherein, The voltage measurement module is used to measure the voltage at the busbar to which the energy storage power station is directly connected; The current measurement module is used to measure the current at the busbar to which the energy storage power station is directly connected; The power calculation module is used to convert the measured voltage and current into power through a formula; The virtual speed regulation system module is used to simulate the frequency regulation principle of the speed regulation system of the synchronous generator and to distribute the unbalanced power; Virtual excitation system module, which simulates the excitation system of synchronous generator for voltage regulation; Virtual synchronous generator module, used to simulate the external characteristics of synchronous generator, control the inverter and increase inertia; Virtual impedance module, used to prevent large current from flowing into the inverter and causing damage to the inverter; Inverter module, used to convert direct current into alternating current; An output voltage module is used to process the real and imaginary parts of the voltage flowing into the module, as well as the voltage amplitude parameters, and output a current that meets the inverter constraint conditions; The battery module includes: a unit battery module, an AC current module and a PQ measurement module; wherein the unit battery module is used to convert the current unit into the battery capacity unit; the AC current module is used to solve the AC current; and the PQ measurement module is used to measure the active power and reactive power at the busbar directly connected to the energy storage power station.

5. A new energy storage configuration method based on frequency response according to claim 1, characterized in that: The minimum power capacity P that the energy storage system needs to supplement under the frequency deviation limit is obtained ESS The calculation formula is: ESS =ΔP xm -ΔP xk .

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