Evaluation method and related device for grid-connected performance of network construction type energy storage power station

Abstract

The invention discloses a method and a related device for evaluating the grid-connected performance of a network construction type energy storage power station. The method comprises the following steps: acquiring basic data and grid-connected performance evaluation data of the energy storage power station; comparing the basic data and the grid-connected performance evaluation data of the energy storage power station with actual operation data of grid-connected equipment of the energy storage power station, and judging whether the energy storage power station is in a normal working state or not; if the power station is in the normal working state, basic data of the energy storage power station and grid-connected performance evaluation data of the energy storage power station in an evaluation period are analyzed, and grid-connected operation is carried out; calculating a key index of grid-connected operation of the energy storage system unit according to the grid-connected operation demand; and judging the grid-connected performance of the grid-forming energy storage power station according to the key indexes. The method can improve the fault defense capability of the power grid, effectively supports the frequency and voltage stability of the regional power grid, and guarantees the safe and stable operation of the power grid.

Description

Technical Field

[0001] The present invention relates to a method and a related device for evaluating the grid-connected performance of a grid-connected energy storage power station, and belongs to the technical field of safety assessment of energy storage power stations connected to a power grid. Background Art

[0002] In recent years, the continuous increase in the proportion of new energy has brought severe challenges to the safe and stable operation of the system. Energy storage is an important equipment foundation and key supporting technology for building a new power system with new energy as the main body and ensuring my country's energy security, which is of great significance. Grid-type energy storage can effectively support the frequency and voltage stability of regional power grids through virtual inertia control and other methods, and is an important development direction for large-scale energy storage in the future. The current technology and standards cannot meet the operation effect evaluation and grid-connected function verification of grid-type energy storage power stations. It is necessary to provide an operation effect evaluation plan for grid-type energy storage systems and formulate a grid-connected function verification method for grid-type energy storage systems to strengthen the standardization of energy storage system construction and improve the operation reliability of grid-type energy storage access systems. However, since grid-type energy storage is still in its infancy, the current understanding of the applicable boundaries of grid-type energy storage systems is not clear, and there is a lack of effective verification of the response and support capabilities under fault crossing; the grid-type unit and whole station test evaluation indicators lack relevant standard support, the support capacity evaluation system for grid-type energy storage power stations has not yet been established, and engineering design is difficult to carry out scientifically. Summary of the invention

[0003] The purpose of the present invention is to solve the above-mentioned problems and propose a method and related device for evaluating the grid-connected performance of a grid-type energy storage power station, which fully considers the basic information of the energy storage power station and the operating data within the cycle, verifies and adjusts the data, and evaluates the safety and potential risks of the grid-connected performance of the grid-type energy storage power station based on the charging and discharging characteristics and consistency analysis of the energy storage power station system unit.

[0004] To achieve the above object, the technical solution adopted by the present invention is:

[0005] A method for evaluating the grid-connected performance of a grid-connected energy storage power station comprises the following steps:

[0006] Obtain basic data of energy storage power stations and grid-connected performance evaluation data;

[0007] Compare the basic data of the energy storage power station and the grid-connected performance evaluation data with the actual operation data of the grid-connected equipment of the energy storage power station to determine whether the energy storage power station is in normal working condition;

[0008] If it is in normal working state, the basic data of the energy storage power station and the grid-connected performance evaluation data of the energy storage power station during the evaluation period are analyzed and grid-connected operation is carried out;

[0009] Calculate the key indicators of grid-connected operation of energy storage system units according to grid-connected operation requirements;

[0010] The grid-connected performance of the grid-connected energy storage power station is judged based on key indicators.

[0011] A further improvement of the present invention is that the basic data of the energy storage power station includes the power station name, power station function positioning, primary electrical wiring topology, grid-connected voltage level and grid-connected location, specification parameters of the monitoring system, response grid-connected scheduling time and time-of-use electricity price.

[0012] A further improvement of the present invention is that the grid-connected performance evaluation data of the energy storage power station includes historical data of online monitoring of power station operation electricity, electricity quantity, event sequence and power quality, historical data of power station operation status, energy storage equipment and booster station equipment operation status.

[0013] A further improvement of the present invention is that if it is in a normal working state, the basic data of the energy storage power station and the grid-connected performance evaluation data of the energy storage power station within the evaluation period are analyzed and the grid-connected operation is performed, including the following steps:

[0014] According to the energy storage power station effectively recording functional events and effective charging and discharging events, the energy storage power station's daily, monthly and annual on-grid and off-grid power, the energy storage power station's total power loss, and the energy supply reliability of the station's power consumption history data are evaluated during the cycle. The actual operation data of the energy storage power station and the actual operation data of the energy storage power station's grid-connected equipment are compared. If the energy storage power station's operation requirements are met, it is connected to the grid for operation;

[0015] The number of times the dispatching agency issues instructions to the energy storage power station, the number of times the energy storage power station successfully responds to the dispatching agency's instructions, the charge and discharge capacity, planned outage time, unplanned outage time, and the working time of the energy storage power station during the evaluation period are compared with the voltage, current, and power during the energy storage power station dispatch process. If the voltage, current, and power during the energy storage power station dispatch process are met, the energy storage power station is dispatched.

[0016] A further improvement of the present invention is that the key indicators of the grid-connected operation of the energy storage system unit include the charging and discharging efficiency, the discharge response time, the discharge ramp rate, the overall consistency index of the battery voltage and the overall consistency index of the temperature.

[0017] A further improvement of the present invention is that the charge and discharge efficiency η is calculated by the following formula:

[0018]

[0019] Among them, Wh Di The electrical energy output at rated power, in kilowatt-hours; Wh Ci It is the AC power input into the system during the charging process, measured in kilowatt-hours.

[0020] A further improvement of the present invention is that the discharge response time T D and discharge ramp rate R pet Calculated by the following formula:

[0021] T D =T e -T b (5-2)

[0022]

[0023] Among them, T e It is the time when the output power of the energy storage system reaches the rated discharge power for the first time, in seconds; T b It is the initial time for the energy storage system to respond to the discharge command, in seconds. For energy storage system in T e Power output value at the moment, in kilowatts, P N is the system rated power in kilowatts.

[0024] A further improvement of the present invention is that the overall consistency index δ of the battery voltage is V Calculated by the following formula:

[0025]

[0026] Among them, V i is the voltage of the ith battery cell in a group of batteries; V m is the average voltage of all battery cells in a battery group; N is the number of battery cells in a battery group.

[0027] A further improvement of the present invention is that the overall consistency index δ of the temperature T Calculated by the following formula:

[0028]

[0029] Among them, T i is the temperature of the ith battery cell in a group of batteries; T m is the average temperature of all battery cells in a battery group; N is the number of battery cells in a battery group.

[0030] An evaluation system for the grid-connected performance of a grid-connected energy storage power station, comprising:

[0031] Data acquisition module, used to obtain basic data of energy storage power stations and grid-connected performance evaluation data;

[0032] The judgment module is used to compare the basic data of the energy storage power station and the grid-connected performance evaluation data with the actual operation data of the grid-connected equipment of the energy storage power station to determine whether the energy storage power station is in a normal working state;

[0033] The analysis module is used to analyze the basic data of the energy storage power station and the grid-connected performance evaluation data of the energy storage power station during the evaluation period and perform grid-connected operation if it is in normal working state;

[0034] A key indicator calculation module is used to calculate the key indicators of the grid-connected operation of the energy storage system unit according to the grid-connected operation requirements;

[0035] The performance judgment module is used to judge the grid-connected performance of the grid-connected energy storage power station based on key indicators.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] The present invention calculates the key indicators of the grid-connected operation of the energy storage system unit based on the basic data of the energy storage power station and the grid-connected performance evaluation data; the grid-connected performance of the grid-connected energy storage power station is judged based on the key indicators. The method verifies and adjusts the data based on the basic information of the energy storage power station and the operation data within the cycle to further ensure the safety of the system. The adjusted information provides data support for determining the grid-connected unit and the whole station test evaluation indicators and establishing a grid-connected energy storage power station support capacity evaluation system, and can improve the grid fault defense capability, effectively support the frequency and voltage stability of the regional power grid, and ensure the safe and stable operation of the power grid.

[0038] Furthermore, the present invention analyzes and mines the overall consistency index of battery voltage, and evaluates the battery consistency performance of energy storage power stations from two levels: battery modules and battery strings. Considering that there is a certain follow-up relationship between battery voltage change and charging and discharging, the battery historical data is analyzed separately under charging / discharging state to achieve accurate evaluation of the safety consistency of energy storage power stations. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is the main flow chart of the grid-connected performance evaluation method considering the grid-connected energy storage power station;

[0040] Figure 2 It is a flow chart of the power station energy storage energy test;

[0041] Figure 3 It is a schematic diagram of the topological structure of a large-scale battery energy storage power station;

[0042] Figure 4 It is the voltage range diagram of single battery;

[0043] Figure 5 It is a schematic diagram of the evaluation system structure for the grid-connected performance of a grid-connected energy storage power station. DETAILED DESCRIPTION

[0044] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly and comprehensively understood.

[0045] In the present invention, firstly, the basic information of the energy storage power station, the operating data within the evaluation period of the energy storage power station, the dispatching records and other information are adjusted, and the consistency of the adjusted information and the actual operating information of the energy storage power station is verified;

[0046] Secondly, collect and analyze the historical operation data and dispatch records of the energy storage power station during the evaluation period, and conduct on-site tests in accordance with relevant standards and requirements for indicators that lack operating data support;

[0047] Finally, based on historical data and test data, the grid-connected operation characteristics of the energy storage power station are analyzed, and the battery consistency performance of the lithium battery energy storage power station is analyzed and mined, the key indicators of the grid-connected operation of the energy storage system unit are calculated, and the grid-connected performance verification and evaluation of the grid-connected energy storage power station are realized.

[0048] Example 1

[0049] A method for evaluating the grid-connected performance of a grid-connected energy storage power station of the present invention comprises the following steps:

[0050] Step 1: Collect basic data of energy storage power stations and grid-connected performance evaluation data:

[0051] Step 1-1, basic data of energy storage power station, including power station name, power station function positioning, primary electrical wiring topology, grid-connected voltage level and grid-connected location, specifications and parameters of monitoring system, response grid-connected dispatch time and time-of-use electricity price, etc. Basic data information of energy storage power station, operation data within the evaluation period of energy storage power station, dispatching records and other information are adjusted, and the adjusted information is verified for consistency with the actual operation information of energy storage power station.

[0052] Step 1-2: Grid-connected performance evaluation data of energy storage power stations, including historical data of power station operation electricity, electricity, event sequence and online monitoring of power quality (historical data include rated power, AC power, rated discharge power, initial time and power output value of response to discharge command), power station operation status, energy storage equipment and booster station equipment operation status historical data.

[0053] The basic data of the energy storage power station and the grid-connected performance evaluation data collected by the present invention are more extensive, and can better demonstrate the actual operating function, basic performance and grid-connected performance of the energy storage power station.

[0054] Step 2: Compare the data of Step 1-1 and Step 1-2 with the actual operation data of the energy storage power station grid-connected equipment on site to determine whether the energy storage power station is in a normal working state; if normal, proceed to Step 3;

[0055] Step 3: Analyze the basic data of the energy storage power station in step 1-1 and the grid-connected performance evaluation data of the energy storage power station in step 1-2 within the evaluation period;

[0056] Step 3-1: Based on the effective recording of functional events and effective charging and discharging events of the energy storage power station, evaluate the energy supply reliability of the daily, monthly and annual on-grid and off-grid power of the energy storage power station, the total power loss of the energy storage power station, the power consumption of the station and other historical data within the cycle, and compare the actual operation data of the energy storage power station with the actual operation data of the grid-connected equipment of the energy storage power station. If the operation requirements of the energy storage power station are met, it will be connected to the grid for operation. If the operation requirements of the energy storage power station are not met, it will be operated off-grid or shut down;

[0057] Step 3-2: compare historical data such as the number of times the dispatching agency issues instructions to the energy storage power station during the evaluation period, the number of times the energy storage power station successfully responds to the dispatching agency's instructions, the charge and discharge power, the planned outage time, the unplanned outage time, and the available time (working time of the energy storage power station) with the voltage, current, power and other parameters in the energy storage power station dispatching process. If the voltage, current, power and other parameters in the energy storage power station dispatching process are met, the energy storage power station is dispatched; if the parameters in the energy storage power station dispatching process are not met, it is operated off-grid or shut down.

[0058] Step 3-3: When the grid-connected performance evaluation data of the energy storage power station in step 1-2 lacks the status of the energy storage power station (stability, reliability, economy, etc. of grid-connected operation), no less than 3 continuous functional cycle tests should be carried out on site according to the design functional requirements, and the status of the energy storage power station during each functional event should be recorded.

[0059] Step 3-4: When the charging and discharging time and charging and discharging energy (stability, reliability, economy, etc. of grid-connected operation) in the energy storage power station grid-connected performance evaluation data in step 1-2 are included, no less than 3 charging and discharging cycle tests should be carried out on site at maximum power until the charging and discharging cut-off conditions are met, and the charging and discharging time and charging and discharging energy of each event should be recorded. Figure 2 , the specific process is as follows:

[0060] 1) Charge the energy storage station to the specified SOC upper limit and record the SOC value at this time;

[0061] 2) Stand by for 30 minutes;

[0062] 3) Discharge to the specified SOC lower limit and record the SOC value and time at this time;

[0063] 4) Stand by and let it stand for 30 minutes;

[0064] 5) Charge to the specified SOC upper limit and record the SOC value and time at this time;

[0065] Repeat steps 1)-5) 4 times; repeat steps 1)-5) to test with different power capacities.

[0066] In the present invention, for indicators that lack operational data support, field tests are directly carried out in accordance with relevant standards and requirements to improve the accuracy of evaluation.

[0067] Step 4: According to the different functional event requirements of the grid-connected operation in steps 3-4, such as stability, reliability, and economy, calculate the key indicators of the grid-connected operation of the energy storage system unit, as follows:

[0068] Step 4-1, the charge and discharge efficiency η can be expressed as:

[0069]

[0070] Among them, Wh Di It is the electrical energy output at rated power, in kilowatt-hours (kWh); Wh Ci It is the AC power input into the system during the charging process, measured in kilowatt-hours (kWh).

[0071] Step 4-2, discharge response time T D , discharge ramp rate R pet :

[0072] T D =T e -T b (5-2)

[0073]

[0074] Among them, T e It is the time when the output power of the energy storage system reaches the rated discharge power for the first time, in seconds (s); T b It is the initial time for the energy storage system to respond to the discharge command, in seconds (s). For energy storage system in T e The power output value at the moment, in kilowatts (kW), P N It is the rated power of the system in kilowatts (KW).

[0075] Step 4-3: Analyze the battery system structure in the energy storage power station. The topology of the large-scale battery energy storage power station is as follows: Figure 3As shown, a large-scale battery energy storage power station includes n PCS (Power Conversion System), generally each PCS includes k parallel battery strings, each battery string includes N battery modules, and each battery module includes m battery cells.

[0076] Step 4-4: In the battery consistency evaluation of the energy storage power station, the battery consistency is analyzed with the voltage range as an indicator, and the overall consistency index of the battery voltage is calculated. V , the overall consistency index of temperature δ T :

[0077]

[0078] Among them, V i is the voltage of the ith battery cell in a group of batteries; V m is the average voltage of all battery cells in a group of batteries; T i is the temperature of the ith battery cell in a group of batteries; T m is the average temperature of all battery cells in a battery group; N is the number of battery cells in a battery group.

[0079] The present invention ensures the scientific nature of the grid-connected operation evaluation of the energy storage power station by establishing the charging and discharging efficiency, discharge response time and consistency evaluation index of the energy storage power station.

[0080] The present invention proposes evaluation methods and evaluation conclusions for the grid-connected equipment, basic performance, and grid-connected performance of the energy storage power station, and provides targeted improvement measures to improve the grid-connected performance of the energy storage power station.

[0081] See also Figure 4 , we can see the voltage extreme difference characteristics of the single cell. The operating characteristics of the battery can be judged based on the voltage extreme difference characteristics of the single cell. The voltages of the single cells numbered 10, 64 and 136 are relatively high.

[0082] Step 5: Based on the functional requirements of different events in step 3 and the key indicators in step 4, evaluate the grid-connected equipment, basic performance, and grid-connected performance of the energy storage power station.

[0083] Step 5-1: According to the charge and discharge efficiency η and discharge response time T of the battery in step 4 D , discharge ramp rate R pet , battery system structure, and voltage range are used as indicators to analyze battery consistency. According to the overall consistency index δ of the battery voltage V , the overall consistency index of temperature δ T , evaluate the performance of grid-connected equipment in energy storage power stations;

[0084] If the overall consistency index of the battery voltage δV , the overall consistency index of temperature δ T If both are less than 1%, the battery consistency of the energy storage power station is good and meets the requirements of the grid-connected indicators.

[0085] Step 5-2: Determine the grid connection conditions, including whether the charging and discharging capacity, power station energy efficiency and operating status meet the grid connection requirements.

[0086] Step 5-3: Evaluate the grid-connected performance of the energy storage power station to determine whether it meets the grid-connected requirements; including evaluation of active and reactive power control, primary frequency regulation capability, inertia response capability, grid adaptability, grid-connected operation power quality, and on-grid and off-grid switching capability.

[0087] Step 6: Issue an evaluation report with the evaluation results.

[0088] Step 6-1: After the evaluation of the energy storage power station is completed, a single evaluation conclusion and an overall evaluation report should be given based on the sub-item evaluation results. The single evaluation conclusion should adopt the grid-connected performance evaluation table.

[0089] Step 6-2: The evaluation conclusion should record the individual evaluation results, give evaluation conclusions for each evaluation item, and provide improvement measures or suggestions for unqualified items.

[0090] Step 6-3: The overall evaluation report of the energy storage power station should include the power station overview, basis standards, evaluation items and contents, evaluation methods, and finally give evaluation conclusions and recommendations.

[0091] The present invention is based on the fact that the grid-type energy storage power station can improve the power grid's fault defense capability through the control of parameters such as voltage, current, and power, play an effective supporting role in the frequency and voltage stability of the regional power grid, and ensure the safe and stable operation of the power grid.

[0092] Based on the basic information of the energy storage power station and the operating data within the cycle, the present invention verifies and adjusts the data to further ensure the safety of the system. The adjusted information provides data support for determining the grid-type unit and the whole station test evaluation indicators and establishing a grid-type energy storage power station support capacity evaluation system.

[0093] This paper focuses on analyzing and mining the battery consistency performance of lithium battery energy storage power stations, and evaluates the battery consistency performance of energy storage power stations from two levels: battery modules and battery strings. Considering that there is a certain follow-up relationship between battery voltage changes and charging and discharging, based on the battery historical data, the battery consistency of the charging / discharging state is analyzed to achieve an accurate evaluation of the safety consistency of the energy storage power station.

[0094] Example 2

[0095] See also Figure 5The evaluation system for the grid-connected performance of a grid-connected energy storage power station of the present invention comprises:

[0096] Data acquisition module, used to obtain basic data of energy storage power stations and grid-connected performance evaluation data;

[0097] The judgment module is used to compare the basic data of the energy storage power station and the grid-connected performance evaluation data with the actual operation data of the grid-connected equipment of the energy storage power station to determine whether the energy storage power station is in a normal working state;

[0098] The analysis module is used to analyze the basic data of the energy storage power station and the grid-connected performance evaluation data of the energy storage power station during the evaluation period and perform grid-connected operation if it is in normal working state;

[0099] A key indicator calculation module is used to calculate the key indicators of the grid-connected operation of the energy storage system unit according to the grid-connected operation requirements;

[0100] The performance judgment module is used to judge the grid-connected performance of the grid-connected energy storage power station based on key indicators.

[0101] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0102] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0103] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1A function specified in one or more boxes.

[0104] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0105] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for evaluating the grid-connected performance of a grid-connected energy storage power station, characterized in that: The following steps are involved: Obtain basic data of energy storage power stations and grid-connected performance evaluation data; Compare the basic data of the energy storage power station and the grid-connected performance evaluation data with the actual operation data of the grid-connected equipment of the energy storage power station to determine whether the energy storage power station is in normal working condition; If it is in normal working state, the basic data of the energy storage power station and the grid-connected performance evaluation data of the energy storage power station during the evaluation period are analyzed and grid-connected operation is carried out; Calculate the key indicators of grid-connected operation of energy storage system units according to grid-connected operation requirements; The grid-connected performance of the grid-connected energy storage power station is judged based on key indicators.

2. The method for evaluating the grid-connected performance of a grid-connected energy storage power station according to claim 1, characterized in that: The basic data of the energy storage power station includes the power station name, power station function positioning, primary electrical wiring topology, grid-connected voltage level and grid-connected location, specifications and parameters of the monitoring system, response grid-connected dispatch time and time-of-use electricity price.

3. The method for evaluating the grid-connected performance of a grid-connected energy storage power station according to claim 1, characterized in that: The grid-connected performance evaluation data of energy storage power stations include historical data on online monitoring of power station operation electricity, electricity quantity, event sequence and power quality, historical data on power station operation status, and operation status of energy storage equipment and booster station equipment.

4. The method for evaluating the grid-connected performance of a grid-connected energy storage power station according to claim 1, characterized in that: If it is in normal working state, the basic data of the energy storage power station and the grid-connected performance evaluation data of the energy storage power station during the evaluation period are analyzed and grid-connected operation is carried out, including the following steps: According to the energy storage power station effectively recording functional events and effective charging and discharging events, the energy storage power station's daily, monthly and annual on-grid and off-grid power, the energy storage power station's total power loss, and the energy supply reliability of the station's power consumption history data are evaluated during the cycle. The actual operation data of the energy storage power station and the actual operation data of the energy storage power station's grid-connected equipment are compared. If the energy storage power station's operation requirements are met, it is connected to the grid for operation; The number of times the dispatching agency issues instructions to the energy storage power station, the number of times the energy storage power station successfully responds to the dispatching agency's instructions, the charge and discharge capacity, planned outage time, unplanned outage time, and the working time of the energy storage power station during the evaluation period are compared with the voltage, current, and power during the energy storage power station dispatch process. If the voltage, current, and power during the energy storage power station dispatch process are met, the energy storage power station is dispatched.

5. The method for evaluating the grid-connected performance of a grid-connected energy storage power station according to claim 1, characterized in that: The key indicators of grid-connected operation of energy storage system units include charging and discharging efficiency, discharge response time, discharge ramp rate, overall consistency index of battery voltage and overall consistency index of temperature.

6. The method for evaluating the grid-connected performance of a grid-connected energy storage power station according to claim 5, characterized in that: The charge and discharge efficiency η is calculated by the following formula: Among them, Wh Di The electrical energy output at rated power, in kilowatt-hours; Wh Ci It is the AC power input into the system during the charging process, measured in kilowatt-hours.

7. The method for evaluating the grid-connected performance of a grid-connected energy storage power station according to claim 5, characterized in that: Discharge response time T D and discharge ramp rate R pet Calculated by the following formula: T D =T e -T b (5-2) Among them, T e It is the time when the output power of the energy storage system reaches the rated discharge power for the first time, in seconds; T b It is the initial time for the energy storage system to respond to the discharge command, in seconds. For energy storage system in T e Power output value at the moment, in kilowatts, P N is the system rated power in kilowatts.

8. The method for evaluating the grid-connected performance of a grid-connected energy storage power station according to claim 5, characterized in that: The overall consistency index of battery voltage δ V Calculated by the following formula: Among them, V i is the voltage of the ith battery cell in a group of batteries; V m is the average voltage of all battery cells in a battery group; N is the number of battery cells in a battery group.

9. The method for evaluating the grid-connected performance of a grid-connected energy storage power station according to claim 5, characterized in that: The overall consistency index of temperature is δ T Calculated by the following formula: Among them, T i is the temperature of the ith battery cell in a group of batteries; T m is the average temperature of all battery cells in a battery group; N is the number of battery cells in a battery group.

10. An evaluation system for the grid-connected performance of a grid-connected energy storage power station, characterized in that: include: Data acquisition module, used to obtain basic data of energy storage power stations and grid-connected performance evaluation data; The judgment module is used to compare the basic data of the energy storage power station and the grid-connected performance evaluation data with the actual operation data of the grid-connected equipment of the energy storage power station to determine whether the energy storage power station is in a normal working state; The analysis module is used to analyze the basic data of the energy storage power station and the grid-connected performance evaluation data of the energy storage power station during the evaluation period and perform grid-connected operation if it is in normal working state; A key indicator calculation module is used to calculate the key indicators of the grid-connected operation of the energy storage system unit according to the grid-connected operation requirements; The performance judgment module is used to judge the grid-connected performance of the grid-connected energy storage power station based on key indicators.

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