Multi-level energy storage configuration method and device

Abstract

The invention discloses a multi-level energy storage configuration method and device, and belongs to the technical field of photovoltaic systems. The method comprises the following steps: determining the installed capacity a of a first energy storage unit, the installed capacity b of a second energy storage unit and the installed capacity c of a third energy storage unit step by step based on the total installed capacity k of a hybrid system in a target area and a power output capacity curve of a photovoltaic power station in the target area in a set historical time period; the first energy storage unit arranged on the direct current side, the second energy storage unit arranged on the alternating current side and the third energy storage unit arranged on the high voltage side are matched with one another, and the installed capacity of each energy storage unit is correspondingly determined, so that abandoned electricity on the direct current side and the alternating current side can be absorbed; and meanwhile, a transient supporting effect is achieved, damping, black start, overload capacity and the like are provided, and safe and stable grid-connected service is provided for the whole system.

Description

Technical Field

[0001] This invention belongs to the field of photovoltaic system technology, specifically relating to a multi-level energy storage configuration method and device. Background Technology

[0002] Energy storage can smooth out peak and valley loads when wind and solar power are curtailed, improving the flexibility and reliability of the power system. Under the pressure of absorbing a high proportion of renewable energy, energy storage is regarded as an important means to cope with the large-scale grid connection and absorption of new energy, and is an indispensable key technology for building a new energy system.

[0003] Currently, most energy storage projects only adopt AC-side centralized energy storage, resulting in relatively limited functionality, difficulties in dispatching, and the ability to solve only a small portion of the problems in new energy + energy storage systems. This leads to the idleness and waste of energy storage configurations. Summary of the Invention

[0004] The purpose of this invention is to provide a multi-level energy storage configuration method and apparatus to address the shortcomings of existing photovoltaic system energy storage system configurations mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a multi-level energy storage configuration method applied to a photovoltaic energy storage hybrid system, wherein the photovoltaic energy storage hybrid system has a first energy storage unit arranged on the DC side, a second energy storage unit arranged on the AC side, and a third energy storage unit arranged on the high-voltage side, and the configuration method includes:

[0006] Determine the total installed capacity k of the hybrid system in the target area;

[0007] Obtain the power output capacity curve of photovoltaic power plants in the target area within a set historical time period;

[0008] The installed capacity 'a' of the first energy storage unit is determined based on the difference between the power output capacity and the inverter installed capacity at different points in time within a set historical period.

[0009] The power curtailment and cumulative power curtailment generated by grid dispatch during the historical period are obtained based on the power output capacity curve, and the installed capacity b of the second energy storage unit is determined based on the power curtailment and cumulative power curtailment.

[0010] Acquire current overload and black start demand data for the target area. When the hybrid system meets the configuration conditions under any demand, update the power curtailment and cumulative power curtailment generated by grid dispatch in the historical time period based on the installed capacity b of the second energy storage unit, and determine the installed capacity c of the third energy storage unit based on the updated power curtailment and cumulative power curtailment.

[0011] At least one of a, b, and c above is updated based on the total installed capacity k of the hybrid system in the target area and the economic requirements.

[0012] Preferably, determining the installed capacity 'a' of the first energy storage unit based on the difference between the power output capacity and the inverter installed capacity at different points in time within a set historical period includes:

[0013] The statistical difference includes the positive value distribution and the cumulative sum of positive values, as well as the negative value distribution and the cumulative sum of negative values;

[0014] When the cumulative sum of positive difference values ​​is greater than the cumulative sum of negative difference values, the installed capacity of the first energy storage unit is set to 'a'. Based on the set installed capacity of the first energy storage unit 'a', the positive value sequence of the difference is re-determined, including updating the positive difference value at that time point to 'a' when the positive difference value is greater than 'a', and keeping the positive difference value at that time point unchanged when the positive difference value is less than 'a'.

[0015] And calculate the cumulative sum of the positive value sequence, and update the installed capacity 'a' of the first energy storage unit through grid search so that the cumulative sum of the positive value sequence and the cumulative sum of the negative difference are equal.

[0016] Preferably, determining the installed capacity 'a' of the first energy storage unit based on the difference between the power output capacity and the inverter installed capacity at different points in time within a set historical period further includes:

[0017] When the cumulative sum of positive differences is less than or greater than the cumulative sum of negative differences, the installed capacity of the first energy storage unit is set to 'a'. Based on the set installed capacity of the first energy storage unit 'a', the positive value sequence of the differences is re-determined, including updating the positive difference value at that time point to 'a' when the positive difference value is greater than 'a', and keeping the positive difference value at that time point unchanged when the positive difference value is less than 'a'.

[0018] And calculate the cumulative sum of the positive value sequence, and update the installed capacity 'a' of the first energy storage unit through grid search, so that the cumulative sum of the positive value sequence is 90% to 100% of the cumulative sum of the negative difference.

[0019] Preferably, determining the installed capacity b of the second energy storage unit based on the abandoned power and the cumulative sum of abandoned power includes:

[0020] Set the installed capacity of the second energy storage unit b, redetermine the power sequence based on the set installed capacity of the second energy storage unit b, and include updating the power at that time point to b when the curtailed power is greater than b, and keeping the power at that time point unchanged when the positive difference is less than b.

[0021] And calculate the cumulative sum of the power sequence, and update the installed capacity b of the second energy storage unit through grid search so that the cumulative sum of the power sequence is 90% to 100% of the cumulative sum of abandoned power.

[0022] Preferably, determining the installed capacity c of the third energy storage unit based on the updated curtailed power and the cumulative curtailment includes:

[0023] Set the installed capacity of the third energy storage unit c, and redetermine the updated power sequence based on the set installed capacity of the third energy storage unit c. This includes updating the power at that time point to c when the updated curtailed power is greater than c, and keeping the power at that time point unchanged when the positive difference is less than c.

[0024] And calculate the updated cumulative sum of power sequences, and update the installed capacity c of the third energy storage unit through grid search, so that the updated cumulative sum of power sequences is 90% to 100% of the updated cumulative sum of curtailed power.

[0025] Preferably, the configuration conditions include any one of the following being greater than 5%: the proportion of the available support revenue in the overall system revenue, the proportion of the increase in electricity volume due to the support of the second energy storage unit in the overall discharge volume of the hybrid system, and the proportion of the improvement in the guarantee rate in the whole year.

[0026] Preferably, updating at least one of a, b, and c above based on the total installed capacity k of the hybrid system in the target area and the economic demand includes:

[0027] Calculate the total installed capacity of the first energy storage unit (a), the second energy storage unit (b), and the third energy storage unit (c);

[0028] When the total installed capacity is less than the total installed capacity k, the installed capacity of the second energy storage unit will be changed to kac.

[0029] When the total installed capacity is greater than the total installed capacity k, a, b, and c are reduced proportionally so that the reduced total installed capacity is equal to the total installed capacity k.

[0030] Preferably, updating at least one of a, b, and c above based on the total installed capacity k of the hybrid system in the target area and the economic demand includes:

[0031] The installed capacity of the first energy storage unit a and the installed capacity of the third energy storage unit c are compressed at least once according to a preset ratio, and the installed capacity of the second energy storage unit b is increased accordingly based on the reduction amount of the compressed installed capacity of the first energy storage unit a and the installed capacity of the third energy storage unit c.

[0032] Preferably, the first energy storage unit is an integrated photovoltaic and energy storage unit, the second energy storage unit is a centralized grid-connected energy storage unit, and the third energy storage unit is a high-voltage cascaded energy storage unit.

[0033] This application also proposes a multi-level energy storage configuration device for configuring a photovoltaic energy storage hybrid system. The photovoltaic energy storage hybrid system has a first energy storage unit arranged on the DC side, a second energy storage unit arranged on the AC side, and a third energy storage unit arranged on the high-voltage side. The configuration device includes:

[0034] The first acquisition module is configured to determine the total installed capacity k of the hybrid system in the target area;

[0035] The second acquisition module is configured to acquire the power output capacity curve of the photovoltaic power station in the target area within a set historical time period.

[0036] The first determining module is configured to determine the first energy storage unit installed capacity 'a' based on the difference between the power output capacity and the inverter installed capacity at different points in time within a set historical time period.

[0037] The second determining module is configured to obtain the power curtailment and cumulative power curtailment generated by grid dispatch within a historical time period based on the power output capacity curve, and determine the installed capacity b of the second energy storage unit based on the power curtailment and cumulative power curtailment.

[0038] The third determination module is configured to acquire current overload and black start demand data of the target area. When the hybrid system meets the configuration conditions under any demand, it updates the power curtailment and cumulative power curtailment generated by grid dispatch in the historical time period based on the installed capacity b of the second energy storage unit, and determines the installed capacity c of the third energy storage unit based on the updated power curtailment and cumulative power curtailment.

[0039] The update module is configured to update at least one of a, b, and c above based on the total installed capacity k of the hybrid system in the target area and the economic requirements.

[0040] Compared with the prior art, the beneficial effects of the present invention are:

[0041] This application utilizes a first energy storage unit deployed on the DC side, a second energy storage unit deployed on the AC side, and a third energy storage unit deployed on the high-voltage side, working together and determining the installed capacity of each energy storage unit accordingly. On the one hand, it can absorb the curtailed power on both the DC and AC sides, while also providing transient support and offering damping, black start, and overload capacity, thus ensuring the safe and stable grid connection of the overall system. On the other hand, through the optimized configuration of the capacity of the energy storage units, it can meet the photovoltaic power distribution and storage capacity requirements stipulated by policy, and through the synergy of these units, absorb more curtailed power, thereby increasing the revenue from electricity generation. Attached Figure Description

[0042] Figure 1 This is a flowchart of the method in this application;

[0043] Figure 2 This is a schematic diagram of a hybrid system;

[0044] Figure 3 A schematic diagram of the charging process for a hybrid system;

[0045] Figure 4 This is a schematic diagram of the discharge process in a hybrid system. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] A multi-level energy storage configuration method, applied to a photovoltaic energy storage hybrid system, refers to... Figure 2 The photovoltaic energy storage hybrid system has a first energy storage unit arranged on the DC side, a second energy storage unit arranged on the AC side, and a third energy storage unit arranged on the high-voltage side, as shown in the figure. Figure 1 The configuration method includes:

[0048] S100: Determine the total installed capacity k of the hybrid system in the target area;

[0049] S200: Obtain the power output capacity curve of the photovoltaic power station in the target area within a set historical time period;

[0050] S300: Determine the installed capacity a of the first energy storage unit based on the difference between the power output capacity and the inverter installed capacity at different points in time within a set historical period.

[0051] S400: Based on the power output capacity curve, obtain the power curtailment and cumulative power curtailment generated by grid dispatch within a historical time period, and determine the installed capacity b of the second energy storage unit based on the power curtailment and cumulative power curtailment.

[0052] S500: Obtain the current overload and black start demand data of the target area. When the hybrid system meets the configuration conditions under any demand, update the power curtailment and cumulative power curtailment generated by grid dispatch in the historical time period based on the installed capacity b of the second energy storage unit, and determine the installed capacity c of the third energy storage unit based on the updated power curtailment and cumulative power curtailment.

[0053] S600: Update at least one of a, b, and c above based on the total installed capacity k of the hybrid system in the target area and the economic requirements.

[0054] In some embodiments, the first energy storage unit is configured as an integrated photovoltaic-energy storage system, that is, it is connected to the photovoltaic system through an inverter. The DC output of the photovoltaic system is converted into AC output by the inverter and supplied to the first energy storage unit. Correspondingly, the second energy storage unit is configured as a centralized grid-connected energy storage system and is directly connected to the output of the photovoltaic system. At the same time, it is connected to the external power grid through an inverter. The third energy storage unit is configured as a high-voltage cascaded energy storage system, that is, a grid-connected energy storage system.

[0055] In some embodiments, the total installed capacity k of the hybrid system in the target area can be determined by calculating the required energy storage system capacity and duration based on the target area's (e.g., local) policy requirements (e.g., the photovoltaic-to-storage ratio and market demand in the target area) and the photovoltaic system capacity.

[0056] In some embodiments, the acquisition of the power output capacity curve of a photovoltaic power plant within a set historical time period needs to take into account the typical meteorological conditions of the target area in a given year, as well as the capacity ratio and inverter installed capacity of the photovoltaic power plant, in order to improve the accuracy of the power output capacity curve.

[0057] In some embodiments, in step S500, the configuration conditions include any one of the following being greater than 5%: the proportion of the available support revenue in the overall system revenue, the proportion of the increase in electricity due to the support of the second energy storage unit in the overall discharge of the hybrid system, and the proportion of the improvement in the guarantee rate in the whole year.

[0058] Specifically, the support revenue that can be obtained is in the overall system revenue = (primary frequency regulation revenue + reactive power regulation revenue + reserve revenue + black start revenue) / total power plant revenue. The increase in electricity volume brought by the second energy storage unit in the overall discharge volume of the hybrid system and the improvement in the guarantee rate = (annual discharge volume of the system after configuring the second energy storage unit / discharge volume of the system before configuring the second energy storage unit) - 1.

[0059] In some embodiments, in step S300, determining the first energy storage unit installed capacity 'a' based on the difference between the power output capacity and the inverter installed capacity at different points in time within a set historical time period includes:

[0060] The statistical difference includes the positive value distribution and the cumulative sum of positive values, as well as the negative value distribution and the cumulative sum of negative values;

[0061] When the cumulative sum of positive difference values ​​is greater than the cumulative sum of negative difference values, the installed capacity of the first energy storage unit is set to 'a'. Based on the set installed capacity of the first energy storage unit 'a', the positive value sequence of the difference is re-determined, including updating the positive difference value at that time point to 'a' when the positive difference value is greater than 'a', and keeping the positive difference value at that time point unchanged when the positive difference value is less than 'a'.

[0062] And calculate the cumulative sum of the positive value sequence, and update the installed capacity 'a' of the first energy storage unit through grid search so that the cumulative sum of the positive value sequence and the cumulative sum of the negative difference are equal.

[0063] When the cumulative sum of positive differences is less than or greater than the cumulative sum of negative differences, the installed capacity of the first energy storage unit is set to 'a'. Based on the set installed capacity of the first energy storage unit 'a', the positive value sequence of the differences is re-determined, including updating the positive difference value at that time point to 'a' when the positive difference value is greater than 'a', and keeping the positive difference value at that time point unchanged when the positive difference value is less than 'a'.

[0064] And calculate the cumulative sum of the positive value sequence, and update the installed capacity 'a' of the first energy storage unit through grid search, so that the cumulative sum of the positive value sequence is 90% to 100% of the cumulative sum of the negative difference.

[0065] In some embodiments, the positive value distribution of the difference refers to the statistical result that the difference is positive at a certain point in time within a historical period, and the cumulative sum of the positive value sequence represents the sum of the updated positive value of the difference at different points in time.

[0066] In some embodiments, in step S400, the curtailed power represents the difference between the photovoltaic power that can be generated and the power required for dispatch, that is, curtailed power = photovoltaic power that can be generated - power required for dispatch. Correspondingly, the cumulative curtailment = the sum of (curtailed power * time) within the curtailment period.

[0067] In some embodiments, determining the installed capacity b of the second energy storage unit based on the abandoned power and the cumulative abandoned power in step S400 includes:

[0068] Set the installed capacity of the second energy storage unit b, redetermine the power sequence based on the set installed capacity of the second energy storage unit b, and include updating the power at that time point to b when the curtailed power is greater than b, and keeping the power at that time point unchanged when the positive difference is less than b.

[0069] And calculate the cumulative sum of the power sequence, and update the installed capacity b of the second energy storage unit through grid search so that the cumulative sum of the power sequence is 90% to 100% of the cumulative sum of abandoned power.

[0070] Among them, the cumulative sum of power sequences represents the sum of the power curtailed at different time points.

[0071] In some embodiments, determining the installed capacity c of the third energy storage unit based on the updated curtailed power and the cumulative curtailment in step S500 includes:

[0072] Set the installed capacity of the third energy storage unit c, and redetermine the updated power sequence based on the set installed capacity of the third energy storage unit c. This includes updating the power at that time point to c when the updated curtailed power is greater than c, and keeping the power at that time point unchanged when the positive difference is less than c.

[0073] And calculate the updated cumulative sum of power sequences, and update the installed capacity c of the third energy storage unit through grid search, so that the updated cumulative sum of power sequences is 90% to 100% of the updated cumulative sum of curtailed power.

[0074] Specifically, in step S500, when a second energy storage unit exists, it can absorb and store some of the abandoned electricity (e.g., the portion that the first energy storage unit cannot absorb). That is, under the premise that the first and second energy storage units are arranged, the abandoned power and the cumulative amount of abandoned electricity generated by grid dispatch will be reduced accordingly. In other words, the arrangement of the third energy storage unit needs to be based on the first and second energy storage units.

[0075] In some embodiments, in step S600, the economic demand, for example, may include the grid-connected price of photovoltaics in the target area and the cost levels of integrated photovoltaic and energy storage units (i.e., the first energy storage unit), centralized energy storage (i.e., the second energy storage unit), and high-voltage cascaded energy storage (i.e., the third energy storage unit). It may also include the cost level of the photovoltaic system, the market price of ancillary services in the target area, and the photovoltaic capacity ratio.

[0076] In some embodiments, updating at least one of a, b, and c above based on the total installed capacity k of the hybrid system in the target area and the economic demand includes:

[0077] Calculate the total installed capacity of the first energy storage unit (a), the second energy storage unit (b), and the third energy storage unit (c);

[0078] When the total installed capacity is less than the total installed capacity k, the installed capacity of the second energy storage unit will be changed to kac.

[0079] When the total installed capacity is greater than the total installed capacity k, a, b, and c are reduced proportionally so that the reduced total installed capacity is equal to the total installed capacity k.

[0080] In some embodiments, updating at least one of a, b, and c based on the total installed capacity k of the hybrid system in the target area and the economic demand includes:

[0081] The installed capacity of the first energy storage unit a and the installed capacity of the third energy storage unit c are compressed at least once according to a preset ratio, and the installed capacity of the second energy storage unit b is increased accordingly based on the reduction amount of the compressed installed capacity of the first energy storage unit a and the installed capacity of the third energy storage unit c.

[0082] For example, taking the first energy storage unit's installed capacity 'a' and the third energy storage unit's installed capacity 'c' as an example of compressing them at a rate of 5% each time, after the first update, the first energy storage unit's installed capacity 'a' becomes 'a95%', the second energy storage unit's installed capacity 'b' becomes 'b+a5%+c5%', and the third energy storage unit's installed capacity 'c' becomes 'c95%'. After the second update, the first energy storage unit's installed capacity 'a' becomes 'a90%', the second energy storage unit's installed capacity 'b' becomes 'b+a10%+c10%', and the third energy storage unit's installed capacity 'c' becomes 'c90%'.

[0083] In some embodiments, the above configuration method further includes:

[0084] Simulating photovoltaic and hybrid systems based on determined values ​​of a, b, and c can, for example, include the following two steps:

[0085] Step 1: Simulate the output of the photovoltaic power plant based on typical year data.

[0086] Step 2: Based on historical electricity demand data (e.g., setting historical time periods) and operational history data, perform typical annual electricity demand curve simulation and special operating condition demand simulation.

[0087] In some embodiments, refer to Figure 3 The above configuration method also includes determining the system's charging and discharging requirements:

[0088] Specifically, this includes during charging.

[0089] When the DC power generation exceeds the power consumption, the first energy storage unit is charged first.

[0090] When the AC side is under power limit, the third energy storage unit is charged first, then the first energy storage unit is charged, and finally the second energy storage unit is charged.

[0091] The electricity is discarded after the first, second, and third energy storage units are fully charged.

[0092] During discharge, refer to Figure 4 ,

[0093] When the system has a grid-like requirement, the first energy storage system discharges first, then the third energy storage system discharges, and finally the second energy storage system discharges.

[0094] When the system does not require a grid-like structure, the third energy storage system discharges first, then the first energy storage system discharges, and finally the second energy storage system discharges.

[0095] In some embodiments, the above configuration method further includes fine-tuning the updated values ​​of a, b, and c obtained in step S600 and optimizing the charge-discharge process, specifically including:

[0096] Add the bias value of sampling through the normal distribution to a and c, and change b to kac;

[0097] The charging and discharging sequence of the first, second, and third energy storage units is randomized, and simulation calculations and economic evaluations are performed based on each random result.

[0098] The economic efficiency under different randomization results is compared, and the charging and discharging sequence of the first, second, and third energy storage units is adjusted.

[0099] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A multi-level energy storage configuration method, characterized in that, Applied to a photovoltaic energy storage hybrid system, the photovoltaic energy storage hybrid system has a first energy storage unit arranged on the DC side, a second energy storage unit arranged on the AC side, and a third energy storage unit arranged on the high-voltage side, the configuration method includes: Determine the total installed capacity k of the hybrid system in the target area; Obtain the power output capacity curve of photovoltaic power plants in the target area within a set historical time period; The installed capacity 'a' of the first energy storage unit is determined based on the difference between the power output capacity and the inverter installed capacity at different points in time within a set historical period. The power curtailment and cumulative power curtailment generated by grid dispatch during the historical period are obtained based on the power output capacity curve, and the installed capacity b of the second energy storage unit is determined based on the power curtailment and cumulative power curtailment. Acquire current overload and black start demand data for the target area. When the hybrid system meets the configuration conditions under any demand, update the power curtailment and cumulative power curtailment generated by grid dispatch in the historical time period based on the installed capacity b of the second energy storage unit, and determine the installed capacity c of the third energy storage unit based on the updated power curtailment and cumulative power curtailment. At least one of a, b, and c above is updated based on the total installed capacity k of the hybrid system in the target area and the economic requirements.

2. The multi-level energy storage configuration method according to claim 1, characterized in that: The determination of the first energy storage unit's installed capacity 'a' based on the difference between the power output capacity and the inverter's installed capacity at different points in time within a set historical period includes: The statistical difference includes the positive value distribution and the cumulative sum of positive values, as well as the negative value distribution and the cumulative sum of negative values; When the cumulative sum of positive difference values ​​is greater than the cumulative sum of negative difference values, the installed capacity of the first energy storage unit is set to 'a'. Based on the set installed capacity of the first energy storage unit 'a', the positive value sequence of the difference is re-determined, including updating the positive difference value at that time point to 'a' when the positive difference value is greater than 'a', and keeping the positive difference value at that time point unchanged when the positive difference value is less than 'a'. And calculate the cumulative sum of the positive value sequence, and update the installed capacity 'a' of the first energy storage unit through grid search so that the cumulative sum of the positive value sequence and the cumulative sum of the negative difference are equal.

3. The multi-level energy storage configuration method according to claim 2, characterized in that: The method of determining the first energy storage unit's installed capacity 'a' based on the difference between the power output capacity and the inverter's installed capacity at different points in time within a set historical period also includes: When the cumulative sum of positive differences is less than or greater than the cumulative sum of negative differences, the installed capacity of the first energy storage unit is set to 'a'. Based on the set installed capacity of the first energy storage unit 'a', the positive value sequence of the differences is re-determined, including updating the positive difference value at that time point to 'a' when the positive difference value is greater than 'a', and keeping the positive difference value at that time point unchanged when the positive difference value is less than 'a'. And calculate the cumulative sum of the positive value sequence, and update the installed capacity 'a' of the first energy storage unit through grid search, so that the cumulative sum of the positive value sequence is 90% to 100% of the cumulative sum of the negative difference.

4. The multi-level energy storage configuration method according to claim 1, characterized in that: The determination of the installed capacity b of the second energy storage unit based on the abandoned power and the cumulative sum of abandoned power includes: Set the installed capacity of the second energy storage unit b, redetermine the power sequence based on the set installed capacity of the second energy storage unit b, and include updating the power at that time point to b when the curtailed power is greater than b, and keeping the power at that time point unchanged when the positive difference is less than b. And calculate the cumulative sum of the power sequence, and update the installed capacity b of the second energy storage unit through grid search so that the cumulative sum of the power sequence is 90% to 100% of the cumulative sum of abandoned power.

5. The multi-level energy storage configuration method according to claim 1, characterized in that: The determination of the installed capacity c of the third energy storage unit based on the updated curtailed power and the cumulative curtailment includes: Set the installed capacity of the third energy storage unit c, and redetermine the updated power sequence based on the set installed capacity of the third energy storage unit c. This includes updating the power at that time point to c when the updated curtailed power is greater than c, and keeping the power at that time point unchanged when the positive difference is less than c. And calculate the updated cumulative sum of power sequences, and update the installed capacity c of the third energy storage unit through grid search, so that the updated cumulative sum of power sequences is 90% to 100% of the updated cumulative sum of curtailed power.

6. The multi-level energy storage configuration method according to claim 1, characterized in that: The configuration conditions include any one of the following being greater than 5%: the proportion of the available support revenue in the overall system revenue, the proportion of the incremental electricity generated by the second energy storage unit in the overall discharge of the hybrid system, and the proportion of the improvement in the guarantee rate throughout the year.

7. The multi-level energy storage configuration method according to claim 1, characterized in that: The update of at least one of a, b, and c above based on the total installed capacity k of the hybrid system in the target area and the economic demand includes: Calculate the total installed capacity of the first energy storage unit (a), the second energy storage unit (b), and the third energy storage unit (c); When the total installed capacity is less than the total installed capacity k, the installed capacity of the second energy storage unit will be changed to kac. When the total installed capacity is greater than the total installed capacity k, a, b, and c are reduced proportionally so that the reduced total installed capacity is equal to the total installed capacity k.

8. The multi-level energy storage configuration method according to claim 1, characterized in that: The update of at least one of a, b, and c above based on the total installed capacity k of the hybrid system in the target area and the economic demand includes: The installed capacity of the first energy storage unit a and the installed capacity of the third energy storage unit c are compressed at least once according to a preset ratio, and the installed capacity of the second energy storage unit b is increased accordingly based on the reduction amount of the compressed installed capacity of the first energy storage unit a and the installed capacity of the third energy storage unit c.

9. A multi-level energy storage configuration method according to claim 1, characterized in that: The first energy storage unit is an integrated photovoltaic and energy storage unit, the second energy storage unit is a centralized grid-connected energy storage unit, and the third energy storage unit is a high-voltage cascaded energy storage unit.

10. A multi-level energy storage configuration device, characterized in that: For configuring a photovoltaic energy storage hybrid system, the photovoltaic energy storage hybrid system having a first energy storage unit arranged on the DC side, a second energy storage unit arranged on the AC side, and a third energy storage unit arranged on the high-voltage side, the configuration device includes: The first acquisition module is configured to determine the total installed capacity k of the hybrid system in the target area; The second acquisition module is configured to acquire the power output capacity curve of the photovoltaic power station in the target area within a set historical time period. The first determining module is configured to determine the first energy storage unit installed capacity 'a' based on the difference between the power output capacity and the inverter installed capacity at different points in time within a set historical time period. The second determining module is configured to obtain the power curtailment and cumulative power curtailment generated by grid dispatch within a historical time period based on the power output capacity curve, and determine the installed capacity b of the second energy storage unit based on the power curtailment and cumulative power curtailment. The third determination module is configured to acquire current overload and black start demand data of the target area. When the hybrid system meets the configuration conditions under any demand, it updates the power curtailment and cumulative power curtailment generated by grid dispatch in the historical time period based on the installed capacity b of the second energy storage unit, and determines the installed capacity c of the third energy storage unit based on the updated power curtailment and cumulative power curtailment. The update module is configured to update at least one of a, b, and c above based on the total installed capacity k of the hybrid system in the target area and the economic requirements.

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