A user side energy storage control method and device for multi-functional application

Abstract

The application discloses a multifunctional user-side energy storage control method and device, which comprises the following steps: acquiring real-time operation data and sensitive load data of a power grid; specifically, the real-time operation data comprises a real-time frequency of the power grid, power supply voltage of the power grid to the sensitive load, real-time power of the sensitive load, predicted power, and duration of the power supply voltage of the sensitive load entering a temporary drop interval and critical operation time, wherein the critical operation time is a critical allowable time of the sensitive load to voltage temporary drop; then monitoring a state comprehensive index of the current power grid according to the real-time operation data and the sensitive load data; finally, judging the current power grid state according to the state comprehensive index, and controlling the user-side energy storage to participate in primary frequency modulation or to provide voltage support or to provide voltage standby support according to the current power grid state. As known from the above, the application realizes three composite functions of voltage regulation, frequency modulation and voltage standby support by using the user-side energy storage, further meets the demand of voltage regulation and frequency modulation, and guarantees the stable operation of the power grid.

Description

Technical Field

[0001] This invention belongs to the field of energy storage technology, specifically relating to a user-side energy storage control method and device for multifunctional applications. Background Technology

[0002] Since 2010, energy storage technology has been demonstrated and applied in the power system. After years of technical and application verification, its technical maturity and application effects have been widely recognized, and the industry's awareness of energy storage has gradually increased.

[0003] With the development of new power systems, energy storage technology, as an important flexible regulation resource, will play a crucial role in strengthening power regulation capabilities, enhancing grid flexibility, and promoting the grid integration and consumption of centralized and distributed renewable energy. Among these challenges, fully leveraging the application efficiency of energy storage in the power grid is one of the key issues in its application.

[0004] Voltage sag mitigation and grid frequency regulation are key issues for the stable and safe operation of the power grid. While existing technologies for utilizing energy storage in these areas are constantly emerging, there is a lack of effective research on how to achieve bidirectional reuse switching between voltage sag mitigation and grid frequency regulation using user-side energy storage within the operating cycle. This invention aims to achieve bidirectional reuse switching between user-side energy storage and its participation in primary grid frequency regulation within the operating cycle. This provides flexible frequency regulation and refined voltage regulation resources for the large power grid, improving its safe and stable operation. It also fully coordinates the modes of energy storage participation in grid applications, further exploring its application value and providing technical support for the promotion and application of energy storage. Summary of the Invention

[0005] The purpose of this invention is to solve the problem of how user energy storage can achieve bidirectional multiplexing and switching between voltage sag mitigation and grid frequency regulation during the operating cycle, meeting the comprehensive application requirements of grid frequency regulation and voltage regulation. Furthermore, it provides a multi-functional user-side energy storage control method and device. Specifically, by focusing on the load size and voltage sensitivity of sensitive loads, it comprehensively judges the demand of sensitive loads from both power and time dimensions, thereby accurately monitoring the current grid state and obtaining the current control requirements or energy storage control requirements. This allows for voltage sag mitigation or primary frequency regulation of the current grid, or for advance preparation for subsequent voltage sag mitigation.

[0006] On one hand, the present invention provides a user-side energy storage control method for multifunctional applications, which includes the following steps:

[0007] Step 1: Obtain real-time operating data of the power grid and sensitive load data;

[0008] The real-time operation data of the power grid includes: the real-time frequency of the power grid and the supply voltage of the power grid to sensitive loads; the sensitive load data includes: the real-time power of the sensitive load, the predicted power, the duration of the supply voltage of the sensitive load entering the voltage sag range, and the critical operating time, wherein the critical operating time is the critical allowable time for the sensitive load to withstand voltage sag.

[0009] Step 2: Monitor the current power grid status comprehensive index K based on the real-time operating data and sensitive load data described in Step 1;

[0010] Step 3: Determine the current grid state based on the comprehensive state index K, and control the user-side energy storage to participate in primary frequency regulation, provide voltage support, or provide voltage reserve support based on the current grid state.

[0011] Further optionally, if the duration of the power supply voltage of the sensitive load entering the sag interval is 0, the corresponding state comprehensive index K is -1, and the user-side energy storage participates in the primary frequency regulation;

[0012] If the duration of the power supply voltage of a sensitive load entering the sag range is greater than or equal to the critical operating time, the corresponding state comprehensive index K is 1, and the user-side energy storage provides voltage support.

[0013] Otherwise, the user-side energy storage provides voltage preparation support.

[0014] Alternatively, the formula for the state comprehensive index K is as follows:

[0015]

[0016]

[0017] in, A is a state measurement index; A is a sensitivity coefficient, and it is greater than 1. , These are all state coefficients, and their values ​​are generally set to [1.1, 1.8], depending on the type of sensitive load.

[0018] , These are the predicted power and real-time power at time i, respectively; The critical running time, This represents the duration during which the supply voltage of the sensitive load at time i enters the sag interval.

[0019] The sensitivity coefficient and the state coefficient are empirical values ​​determined based on experimental / actual results, and the predicted power can be obtained through existing technical means. This invention does not impose specific limitations on this.

[0020] Optionally, the operation of providing voltage preparation support for user-side energy storage involves: redistributing the capacity of the user-side energy storage devices, and then performing charging or discharging control operations according to the redistributed battery packs. The number of energy storage packs nB in the preparation voltage regulation phase and the number of battery packs nA in the frequency regulation phase are redistributed as follows:

[0021]

[0022] nA=N-nB

[0023] Where N represents the total number of battery packs in the user-side energy storage device. This indicates rounding down β, where β is the action coefficient, and the following holds:

[0024]

[0025]

[0026] in, As a state measurement metric, it measures the state from two dimensions: power and time. The larger the value, the more urgent the voltage sag threshold of sensitive loads, and the more urgent the need for voltage sag regulation. In other words, the larger the battery pack power and capacity allocated for voltage regulation applications, the smaller the battery pack power and capacity allocated for grid frequency regulation. and They are respectively The maximum and minimum values ​​are actually determined by monitoring state metrics over a period of time. , All are state coefficients. , These are the predicted power and real-time power at time i, respectively; The critical running time, This represents the duration during which the supply voltage of the sensitive load at time i enters the sag interval.

[0027] Further optionally, the operation of user-side energy storage participating in primary frequency regulation is as follows: the energy storage device is set to discharge active power to the grid or the grid charges the energy storage device with active power, or no charging or discharging action is performed, according to the real-time frequency of the grid.

[0028] When the real-time frequency f(t) of the power grid is within the primary frequency regulation dead zone range [fdeadzone-down, fdeadzone-up], the energy storage device does not need to operate.

[0029] When the real-time frequency f(t) of the power grid exceeds the upper limit of the primary frequency regulation dead zone range fdeadzone-up, the power grid charges the energy storage device with active power and sets the charging power to P=K1·(f(t)-fdeadzone-up), where K1 is the proportional coefficient;

[0030] When the real-time frequency f(t) of the power grid is lower than the lower limit of the primary frequency regulation dead zone range fdeadzone-down, the energy storage device discharges active power to the power grid, and sets the discharge power to P=K2·(f(t)-fdeadzone-down), where K2 is a proportional coefficient.

[0031] The primary frequency modulation dead zone range [fdeadzone-down, fdeadzone-up] is usually set to [-0.033, 0.033], but can be adjusted according to the actual situation.

[0032] Further optionally, the voltage sag corresponds to a sag range of [0.1U]. N 0.9U N ], where U N This is the rated voltage.

[0033] Secondly, the present invention provides an apparatus based on the user-side energy storage control method, comprising: an energy storage module and a grid connection module;

[0034] The grid-connected module includes an inverter unit and a control unit. The grid-connected module is connected to the power supply of the sensitive load on the user side, and the energy storage module is connected to the grid-connected module.

[0035] Further optionally, the capacity of the energy storage module satisfies the following condition: the charging and discharging time at rated power is not less than 15 minutes.

[0036] Thirdly, the present invention provides an apparatus based on the user-side energy storage control method, comprising:

[0037] The data acquisition module is used to acquire real-time operating data of the power grid and sensitive load data;

[0038] The real-time operation data of the power grid includes: the real-time frequency of the power grid and the supply voltage of the power grid to sensitive loads; the sensitive load data includes: the real-time power of the sensitive load, the predicted power, the duration of the supply voltage of the sensitive load entering the voltage sag range, and the critical operating time, wherein the critical operating time is the critical allowable time for the sensitive load to withstand voltage sag.

[0039] The status comprehensive index calculation module is used to monitor the current power grid status comprehensive index K using the real-time operating data and the sensitive load data.

[0040] The control module is used to determine the current grid state based on the comprehensive state index K, and control the user-side energy storage to participate in primary frequency regulation, provide voltage support, or provide voltage reserve support based on the current grid state.

[0041] Fourthly, the present invention provides a computer-readable storage medium storing a computer program that is invoked by a processor to implement:

[0042] Steps of a user-side energy storage control method for a multi-functional application.

[0043] Beneficial effects

[0044] The user-side energy storage control method provided by this invention acquires real-time power grid operation data and sensitive load data to predict the operating status of energy storage devices in advance, and sets corresponding control strategies. This enables the switching of three application functions: primary frequency regulation, voltage sag mitigation, and voltage reserve support. It fully explores and leverages the voltage and frequency regulation functions of user-side energy storage for sensitive loads, providing technical support for the promotion and application of energy storage. On the one hand, it solves the problem of power grid voltage sag and provides regulation resources for power grid frequency stability regulation; on the other hand, it improves the application economy of traditional user-side energy storage, thus contributing to the promotion of energy storage in the power grid.

[0045] Furthermore, this invention considers not only the current voltage / frequency regulation requirements but also future frequency / voltage regulation requirements, thus providing advance voltage preparation support. To this end, a comprehensive state index is proposed, which divides the power grid state into three categories: participating in primary frequency regulation, participating in voltage support, and providing voltage preparation support. When in an intermediate state, corresponding to voltage preparation support, the capacity of energy storage devices on the user side is reallocated to prepare for future frequency / voltage regulation, further ensuring the efficiency and effectiveness of frequency / voltage regulation switching.

[0046] Furthermore, this invention introduces an action coefficient β to determine the number of energy storage battery packs allocated to the voltage preparation support state. This allows for flexible allocation of battery pack states based on operating conditions, preparing for a smooth transition during frequency and voltage regulation. Specifically, a larger action coefficient β results in more energy storage battery packs entering the voltage preparation support state, shorter switching time during emergency adjustments, and faster response speed. This is particularly important for ensuring the stability of voltage-sensitive loads. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of the control logic of the user-side energy storage control method provided by the present invention;

[0048] Figure 2 This is a schematic diagram of the user-side energy storage device provided by the present invention;

[0049] Figure 3 This is a schematic diagram of an apparatus based on the user-side energy storage control method provided in Embodiment 2. Detailed Implementation

[0050] This invention provides a multi-functional user-side energy storage control method that aims to utilize user-side energy storage to achieve three functions: voltage regulation, frequency regulation, and voltage reserve support. This further meets the requirements for voltage and frequency regulation and ensures the stable operation of the power grid. The invention will be further described below with reference to embodiments.

[0051] Example 1:

[0052] This embodiment provides a user-side energy storage control method for multi-functional applications. By acquiring real-time grid operation data and sensitive load data, it pre-assesses the operational status of energy storage devices and designs the physical devices and control strategies for energy storage, thereby supporting multiple applications such as primary frequency regulation and voltage sag mitigation. Specifically, it includes the following steps:

[0053] Step 1: Obtain real-time operating data of the power grid and sensitive load data.

[0054] The real-time operation data of the power grid includes: the real-time frequency of the power grid and the supply voltage of the power grid to sensitive loads; the sensitive load data includes: the real-time power of the sensitive load, the predicted power, the duration of the supply voltage of the sensitive load entering the voltage sag range, and the critical operating time. The critical operating time is the critical allowable time for the sensitive load to withstand voltage sag, which is used to characterize the requirements of the sensitive load for voltage stability. That is, when the duration of the voltage sag is t0, the sensitive load will affect the stable operation of the voltage.

[0055] Step 2: Monitor the current power grid status comprehensive index K based on the real-time operating data and the sensitive load data described in Step 1.

[0056] like Figure 2 As shown, first input the variables:

[0057] 1) Real-time operation data of the power grid (current time i, power grid operating frequency f) i The voltage U supplied by the power grid to the sensitive load at time i. i )

[0058] 2) Sensitive load operating status data (real-time power P of the sensitive load at time i) Sen-i The duration t of the supply voltage of the sensitive load entering the sag interval at time i. i It should be understood that the duration t iThe timing unit is more precise than the second. For sensitive loads with different precision and using different units of measurement, it should basically meet the requirements of measurement accuracy in milliseconds (ms) and the predicted power P of the sensitive load. for-i ;

[0059] 3) Critical time t0 for voltage requirements of sensitive loads (the time unit of t0 and t...) i same).

[0060] Then, a comprehensive assessment is conducted using real-time operational data and sensitive load data. The formula for the comprehensive state index K is as follows:

[0061]

[0062]

[0063] in, A is a state measurement index, and A is a sensitivity coefficient. , These are all state coefficients, typically taking values ​​of [1.1, 1.8]. , These are the predicted power and real-time power at time i, respectively; The critical running time, This represents the duration during which the supply voltage of the sensitive load at time i enters the sag interval.

[0064] Step 3: Determine the current grid state based on the comprehensive state index K, and control the user-side energy storage to participate in primary frequency regulation, provide voltage support, or provide voltage reserve support based on the current grid state.

[0065] This invention assesses the state of the power grid based on the comprehensive state index K, classifying it into three categories: a, b, and c. Category a represents the primary frequency regulation demand state, category b represents the voltage support demand state, and category c represents the voltage support preparation state. The specific assessment rules are as follows:

[0066] 1) When K∈{-1}, the state is determined to be in state a (state 2), and the energy storage device needs to participate in a frequency regulation (strategy 2).

[0067] 2) When K∈{1}, the overall state is determined to be b (state 1), and the energy storage device needs to provide voltage support (strategy 1).

[0068] 3) When K∉{1, -1}, the overall state is determined to be c (state 3), and the energy storage device needs to perform voltage preparation support (strategy 3).

[0069] Then, based on the control commands determined by the control strategy, the active and reactive power processing control process of the stored energy is completed by controlling the energy storage device, thereby realizing the above-mentioned voltage support, primary frequency regulation, and voltage preparation support.

[0070] Regarding the participation of energy storage devices in primary frequency regulation: the energy storage device is set to discharge active power to the grid or the grid charges the energy storage device with active power, or not to charge or discharge, based on the real-time frequency f(t) of the grid.

[0071] When the real-time frequency f(t) of the power grid is within the dead zone range [fdeadzone-down, fdeadzone-up], the energy storage device does not need to operate.

[0072] When the real-time frequency f(t) of the power grid exceeds the upper limit of the dead zone range fdeadzone-up, the power grid charges the energy storage device with active power to complete the active power transfer and storage function of the power grid, and sets the charging power to P=K1·(f(t)-fdeadzone-up), where K1 is the proportional coefficient.

[0073] When the real-time frequency f(t) of the power grid is lower than the lower limit of the dead zone range fdeadzone-down, the energy storage device discharges active power to the power grid to complete the active power support of the power grid, and sets the discharge power as P=K2·(f(t)-fdeadzone-down), where K2 is a proportional coefficient.

[0074] Regarding voltage support from energy storage devices: Energy storage devices are used to directly supply power to sensitive loads, thus providing voltage support for sensitive loads; if no voltage support is provided, the power grid lines supply power to the sensitive loads.

[0075] Regarding voltage preparation support for energy storage devices: this involves the redistribution of capacity of energy storage devices on the user side. A larger λ value results in a larger sum of power and capacity allocated to battery packs for voltage regulation applications, while a smaller sum of power and capacity allocated to battery packs for grid frequency regulation. The signals from both are superimposed, and the grid-connected module sets the grid to charge the energy storage with active power, completing the active power transfer and storage function to the grid. This enables the energy storage to fulfill its primary frequency regulation role in the grid and provide reserves for grid sag mitigation.

[0076] Specifically, the number of energy storage groups nB in the battery pack to be regulated and the number of battery packs nA in the frequency regulation state are redistributed as follows:

[0077]

[0078] nA=N-nB

[0079] Where N represents the total number of battery packs in the user-side energy storage device. This indicates rounding down β, where β is the action coefficient, and the following holds:

[0080]

[0081] in, and They are respectively The maximum and minimum values.

[0082] In summary, the user-side energy storage control method provided by this invention achieves the switching function of three applications: primary frequency regulation of the power grid, voltage sag management, and voltage reserve support, through optimization of the control strategy.

[0083] Example 2:

[0084] like Figure 3 As shown, this embodiment provides an apparatus based on the user-side energy storage control method, comprising: an energy storage module and a grid-connected module. The energy storage module is connected to the grid-connected module, which is connected to the power supply of the sensitive load on the user side, thus connecting the energy storage module to the power grid and the sensitive load through the grid-connected module. The grid-connected module includes an inverter unit and a control unit. The capacity of the energy storage module satisfies the requirement that the charging and discharging time at rated power is not less than 15 minutes.

[0085] This embodiment is based on the user-side energy storage control method of Embodiment 1. The energy storage module switches between voltage support, primary frequency regulation, and voltage preparation support through the control of the grid-connected module. Specifically, during voltage support, the grid-connected module is activated to supply power to sensitive loads using the energy storage device, thus completing the voltage support function. When the grid voltage recovers, the grid-connected module switches the operating strategy of the energy storage device, exiting the voltage support mode, and the power supply to sensitive loads continues to be supported by the grid. During primary frequency regulation, the grid-connected module controls the energy storage module to perform corresponding charging and discharging. During voltage preparation support, corresponding control is performed based on the determined number of energy storage groups nB for voltage regulation and the number of battery groups nA in frequency regulation mode.

[0086] It should be noted that using a grid-connected module to implement the aforementioned control functions of voltage support, primary frequency regulation, and voltage reserve support is a conventional control operation in the field, and therefore will not be described in detail. Furthermore, this embodiment is described from the perspective of the hardware configuration of the user-side energy storage device; the next embodiment will be described from the perspective of functional module division.

[0087] Example 3:

[0088] The present invention provides an apparatus based on the user-side energy storage control method, which includes a data acquisition module, a state index calculation module, and a control module.

[0089] The data acquisition module is used to acquire real-time operating data of the power grid and sensitive load data. The real-time operating data of the power grid includes: the real-time frequency of the power grid and the supply voltage of the power grid to the sensitive load; the sensitive load data includes: the real-time power of the sensitive load, the predicted power, the duration of the supply voltage of the sensitive load entering the voltage sag range, and the critical operating time, wherein the critical operating time is the critical allowable time for the sensitive load to withstand voltage sag.

[0090] The status comprehensive index calculation module is used to monitor the current power grid status comprehensive index K using the real-time operating data and the sensitive load data.

[0091] The control module is used to determine the current grid state based on the comprehensive state index K, and to control the user-side energy storage to participate in primary frequency regulation, provide voltage support, or provide voltage reserve support based on the current grid state.

[0092] It should be noted that this embodiment describes the energy storage device from the perspective of functional module division. That is, the aforementioned module units can be implemented as software functional units. For the specific implementation process of each module, please refer to the content of the above method, which will not be repeated here. It should be understood that the above functional module division is only a logical functional division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Furthermore, the integrated units can be implemented in either hardware or software functional units.

[0093] Example 4:

[0094] This embodiment provides a computer-readable storage medium storing a computer program that is called by a processor to implement the steps of a user-side energy storage control method for a multi-functional application. Specific implementation:

[0095] Step 1: Obtain real-time operating data of the power grid and sensitive load data;

[0096] The real-time operation data of the power grid includes: the real-time frequency of the power grid and the supply voltage of the power grid to sensitive loads; the sensitive load data includes: the real-time power of the sensitive load, the predicted power, the duration of the supply voltage of the sensitive load entering the voltage sag range, and the critical operating time, wherein the critical operating time is the critical allowable time for the sensitive load to withstand voltage sag.

[0097] Step 2: Monitor the current power grid status comprehensive index K based on the real-time operating data and sensitive load data described in Step 1;

[0098] Step 3: Determine the current grid state based on the comprehensive state index K, and control the user-side energy storage to participate in primary frequency regulation, provide voltage support, or provide voltage reserve support based on the current grid state.

[0099] Please refer to the explanation of the method above for the specific implementation process of each step.

[0100] The computer-readable storage medium can be an internal storage unit of the controller as described in any of the foregoing embodiments, such as the controller's hard drive or memory. The readable storage medium can also be an external storage device of the controller, such as a plug-in hard drive, Smart Media Card (SMC), Secure Digital (SD) card, or Flash Card equipped on the controller. Further, the readable storage medium can include both the controller's internal storage unit and external storage devices. The readable storage medium is used to store the computer program and other programs and data required by the controller. The readable storage medium can also be used to temporarily store data that has been output or will be output.

[0101] Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned readable storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0102] It should be emphasized that the examples described in this invention are illustrative rather than limiting. Therefore, this invention is not limited to the examples described in the specific embodiments. Any other embodiments derived by those skilled in the art based on the technical solutions of this invention, without departing from the spirit and scope of this invention, whether modifications or substitutions, are also within the protection scope of this invention.

Claims

1. A user-side energy storage control method for multifunctional applications, characterized in that: Includes the following steps: Step 1: Obtain real-time operating data of the power grid and sensitive load data; The real-time operation data of the power grid includes the real-time frequency of the power grid and the supply voltage of the power grid to sensitive loads; the sensitive load data includes the real-time power, predicted power, duration of the supply voltage of the sensitive load entering the voltage sag range, and critical operating time, wherein the critical operating time is the critical allowable time for the sensitive load to withstand voltage sag. Step 2: Monitor the current power grid status comprehensive index K based on the real-time operating data and sensitive load data described in Step 1; Step 3: Determine the current grid state based on the comprehensive state index K, and control the user-side energy storage to participate in primary frequency regulation, provide voltage support, or provide voltage reserve support based on the current grid state; The formula for the comprehensive state index K is as follows: in, A is a state measurement index, and A is a sensitivity coefficient. , All are state coefficients. , These are the predicted power and real-time power of the sensitive load at time i, respectively. The critical running time, This represents the duration during which the supply voltage of the sensitive load at time i enters the sag interval.

2. The user-side energy storage control method according to claim 1, characterized in that: If the duration of the power supply voltage of a sensitive load entering the sag range is 0, the corresponding state comprehensive index K is -1, and the user-side energy storage participates in the primary frequency regulation. If the duration of the power supply voltage of a sensitive load entering the sag range is greater than or equal to the critical operating time, the corresponding state comprehensive index K is 1, and the user-side energy storage provides voltage support. Otherwise, the user-side energy storage provides voltage preparation support.

3. The user-side energy storage control method according to claim 1, characterized in that: The operation for voltage preparation support of user-side energy storage is as follows: the capacity of the user-side energy storage devices is redistributed, and then charging or discharging control operations are performed according to the redistributed battery packs. The number of energy storage packs nB for voltage regulation and the number of battery packs nA in frequency regulation state are redistributed as follows: nA=N-nB Where N represents the total number of battery packs in the user-side energy storage device. This indicates rounding down β, where β is the action coefficient, and the following holds: in, As a measure of state, and They are respectively The maximum and minimum values, , All are state coefficients. , These are the predicted power and real-time power at time i, respectively; The critical running time, This represents the duration during which the supply voltage of the sensitive load at time i enters the sag interval.

4. The user-side energy storage control method according to claim 1, characterized in that: The operation of user-side energy storage participating in primary frequency regulation is as follows: the energy storage device is set to discharge active power to the grid or the grid charges the energy storage device with active power, or no charging or discharging action is performed, according to the real-time frequency of the grid. When the real-time frequency of the power grid is within the primary frequency regulation dead zone [fdeadzone-down, fdeadzone-up], the energy storage device does not need to operate. When the real-time frequency of the power grid exceeds the upper limit of the primary frequency regulation dead zone range fdeadzone-up, the power grid charges the energy storage device with active power and sets the charging power to P=K1·(f(t)-fdeadzone-up), where K1 is the proportional coefficient and f(t) is the real-time frequency of the power grid. When the real-time frequency of the power grid is lower than the lower limit of the primary frequency regulation dead zone range fdeadzone-down, the energy storage device discharges active power to the power grid, and sets the discharge power to P=K2·(f(t)-fdeadzone-down), where K2 is a proportional coefficient.

5. The user-side energy storage control method according to claim 1, characterized in that: The voltage sag corresponds to a sag range of [0.1U]. N 0.9U N ], where U N This is the rated voltage.

6. An apparatus based on the user-side energy storage control method according to any one of claims 1-5, characterized in that: include: Energy storage modules and grid connection modules; The grid-connected module includes an inverter unit and a control unit. The grid-connected module is connected to the power supply of the sensitive load on the user side, and the energy storage module is connected to the grid-connected module.

7. The apparatus according to claim 6, characterized in that: The energy storage module has the following capacity requirement: the charging and discharging time at rated power is not less than 15 minutes.

8. An apparatus based on the user-side energy storage control method according to any one of claims 1-5, characterized in that: include: The data acquisition module is used to acquire real-time operating data of the power grid and sensitive load data; The real-time operation data of the power grid includes: the real-time frequency of the power grid and the supply voltage of the power grid to sensitive loads; the sensitive load data includes: the real-time power of the sensitive load, the predicted power, the duration of the supply voltage of the sensitive load entering the voltage sag range, and the critical operating time, wherein the critical operating time is the critical allowable time for the sensitive load to withstand voltage sag. The status comprehensive index calculation module is used to monitor the current power grid status comprehensive index K using the real-time operating data and the sensitive load data. The control module is used to determine the current grid state based on the comprehensive state index K, and control the user-side energy storage to participate in primary frequency regulation, provide voltage support, or provide voltage reserve support based on the current grid state.

9. A computer-readable storage medium, characterized in that: The computer program is stored and is invoked by the processor to implement: The steps of the user-side energy storage control method according to any one of claims 1-5.

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