Method and system for improving comprehensive efficiency of energy storage power station system

Abstract

The invention discloses a method and a system for improving the comprehensive efficiency of an energy storage power station system. The method comprises the following steps: determining a comprehensive efficiency assessment value and the comprehensive efficiency of an energy storage power station before optimization; judging whether the comprehensive efficiency of the energy storage power station before optimization reaches the comprehensive efficiency assessment value or not; when the comprehensive efficiency of the energy storage power station before optimization does not reach the comprehensive efficiency assessment value, establishing a comprehensive efficiency optimization model of the energy storage power station system; and solving the comprehensive efficiency optimization model of the energy storage power station system to obtain a comprehensive efficiency improvement strategy of the energy storage power station system so as to realize comprehensive efficiency optimization of the energy storage power station system. The comprehensive efficiency of the energy storage power station system can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage power station optimization, and in particular to a method and system for improving the comprehensive efficiency of an energy storage power station system. Background Art

[0002] At present, the scale of renewable energy power generation is increasing, and energy storage has become an important supporting technology for new power systems. Stimulated by the power market, non-pumped energy storage technologies such as electrochemical energy storage, compressed air heat storage, and flywheel energy storage have entered industrialization, and independent energy storage power stations and shared energy storage have developed rapidly. Among them, electrochemical energy storage, supported by the electric vehicle industry, is particularly prominent in the field of non-pumped energy storage technology, mainly lithium-ion batteries, and has leaped from power batteries to large-scale energy storage batteries. Therefore, it is of great significance to analyze the factors affecting the overall efficiency of the system and the key technologies to improve it with lithium battery energy storage as the focus.

[0003] Among the many factors that affect the comprehensive efficiency of energy storage power stations, the power supply mode of auxiliary loads and the control strategy of the energy storage cabin temperature control system have the greatest impact. Therefore, it is necessary to provide a comprehensive efficiency improvement plan for energy storage power station systems that takes into account the power supply mode of auxiliary loads and the control strategy of the energy storage cabin temperature control system. Summary of the invention

[0004] The present invention aims to solve the technical problems in the related art at least to a certain extent. To this end, the first object of the present invention is to provide a method for improving the comprehensive efficiency of an energy storage power station system, which can effectively improve the comprehensive efficiency of the energy storage power station system.

[0005] The second object of the present invention is to provide a system for improving the comprehensive efficiency of an energy storage power station system.

[0006] To achieve the above object, the present invention is implemented through the following technical solutions:

[0007] A method for improving the comprehensive efficiency of an energy storage power station system, comprising:

[0008] Determine the comprehensive efficiency assessment value and the comprehensive efficiency of the energy storage power station before optimization;

[0009] Determine whether the comprehensive efficiency of the energy storage power station before optimization reaches the comprehensive efficiency assessment value;

[0010] When the comprehensive efficiency of the energy storage power station before optimization does not reach the comprehensive efficiency assessment value, establishing a comprehensive efficiency optimization model for the energy storage power station system;

[0011] Solve the comprehensive efficiency optimization model of the energy storage power station system to obtain a comprehensive efficiency improvement strategy for the energy storage power station system, so as to achieve comprehensive efficiency optimization of the energy storage power station system.

[0012] Preferably, determining the comprehensive efficiency of the energy storage power station before optimization includes:

[0013] Obtain the historical daily average on-grid power and historical daily average off-grid power of the energy storage power station;

[0014] The comprehensive efficiency of the energy storage power station before optimization is determined based on the historical average daily grid-connected power and historical average daily grid-offline power of the energy storage power station.

[0015] Preferably, the objective function of the energy storage power station system comprehensive efficiency optimization model is a function established with the goal of minimizing ΔP, where ΔP is a statistical value of the auxiliary load of the energy storage power station that is converted from self-powered electricity to station-powered electricity.

[0016] Preferably, the constraints of the comprehensive efficiency optimization model of the energy storage power station system include: the start and end temperature constraints of the energy storage power station temperature control system stopping working, the power saving constraints after the energy storage power station temperature control system is optimized, the auxiliary load constraints of changing the self-power supply to the station power supply, and the comprehensive efficiency constraints of the energy storage power station.

[0017] Preferably, the maximum allowable temperature difference of the batteries of the energy storage power station is obtained, so as to determine the start and end temperature constraint conditions for stopping the operation of the temperature control system of the energy storage power station based on the maximum allowable temperature difference of the batteries of the energy storage power station.

[0018] Preferably, the start and end temperatures at which the temperature control system of the energy storage power station stops working, the rated power of the temperature control system of the energy storage power station, and a list of daily average prefabricated cabin battery cell statistical durations are obtained before optimization, so as to determine the power saving constraint conditions after the temperature control system of the energy storage power station is optimized.

[0019] Preferably, the auxiliary load statistics of the station transformer power supply and the rated capacity of the station transformer in the auxiliary load of the energy storage power station are obtained to determine the auxiliary load constraint conditions for changing the self-power supply to the station transformer power supply.

[0020] Preferably, the no-load loss and load loss of the station transformer are obtained so as to determine the comprehensive efficiency constraint conditions of the energy storage power station based on the no-load loss, load loss, rated capacity, historical daily average online power and historical daily average offline power of the energy storage power station, and the comprehensive efficiency assessment value of the station transformer.

[0021] Preferably, the energy storage power station system comprehensive efficiency optimization model is solved to obtain the start and end temperatures at which the temperature control system of the energy storage power station stops working after optimization and the auxiliary load power when the self-power supply is changed to the station-powered transformer power supply. The energy storage power station system comprehensive efficiency improvement strategy is:

[0022] The start and end temperatures at which the temperature control system of the energy storage power station stops working are set to the start and end temperatures at which the temperature control system of the energy storage power station stops working after optimization, and the auxiliary load corresponding to the auxiliary load power is changed from self-power supply to station-powered transformer power supply.

[0023] To achieve the above-mentioned object, the second aspect of the present invention provides a system for improving the comprehensive efficiency of an energy storage power station system, comprising:

[0024] A determination module, used to determine the comprehensive efficiency assessment value and the comprehensive efficiency of the energy storage power station before optimization;

[0025] A judgment module, used to judge whether the comprehensive efficiency of the energy storage power station before optimization reaches the comprehensive efficiency assessment value;

[0026] A construction module is used to establish a comprehensive efficiency optimization model of the energy storage power station system when the comprehensive efficiency of the energy storage power station before optimization does not reach the comprehensive efficiency assessment value;

[0027] The solution module is used to solve the comprehensive efficiency optimization model of the energy storage power station system and obtain a comprehensive efficiency improvement strategy for the energy storage power station system, so as to achieve comprehensive efficiency optimization of the energy storage power station system.

[0028] The present invention has at least the following technical effects:

[0029] The present invention provides a method and system for improving the comprehensive efficiency of an energy storage power station system. The method first evaluates whether the current comprehensive efficiency of the energy storage power station reaches the comprehensive efficiency assessment value, that is, meets the assessment requirements. If not, information related to the temperature control system of the energy storage power station and the auxiliary load power supply is obtained. Under the premise of not modifying the energy storage power station, the comprehensive efficiency of the energy storage power station system is improved at the minimum cost to meet the assessment requirements. An energy storage power station system comprehensive efficiency optimization model is established and solved to obtain a strategy for improving the comprehensive efficiency of the energy storage power station system, thereby improving the comprehensive efficiency of the energy storage power station system.

[0030] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The present invention is a flowchart of a method for improving the overall efficiency of an energy storage power station system according to an embodiment of the present invention.

[0032] Figure 2 This is a flowchart of an implementation method for improving the comprehensive efficiency of an energy storage power station system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0033] The present embodiment is described in detail below, and examples of the embodiment are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0034] The method and system for improving the comprehensive efficiency of the energy storage power station system of this embodiment will be described below with reference to the accompanying drawings.

[0035] Figure 1 Flow chart of the method for improving the comprehensive efficiency of the energy storage power station system according to an embodiment of the present invention. Figure 1 As shown, the method includes:

[0036] Step S101: Determine the comprehensive efficiency assessment value and the comprehensive efficiency of the energy storage power station before optimization.

[0037] Step S102: Determine whether the comprehensive efficiency of the energy storage power station before optimization reaches the comprehensive efficiency assessment value.

[0038] Step S103: When the comprehensive efficiency of the energy storage power station before optimization does not reach the comprehensive efficiency assessment value, a comprehensive efficiency optimization model of the energy storage power station system is established.

[0039] Step S104: solving the energy storage power station system comprehensive efficiency optimization model to obtain a comprehensive efficiency improvement strategy for the energy storage power station system to achieve comprehensive efficiency optimization of the energy storage power station system.

[0040] In this embodiment, it is possible to first evaluate whether the current comprehensive efficiency of the energy storage power station meets the assessment requirements based on the comprehensive efficiency assessment value. If not, information related to the temperature control system of the energy storage power station and the power supply of the auxiliary load is obtained. Without modifying the energy storage power station, the comprehensive efficiency of the energy storage power station system is improved at the minimum cost to meet the assessment requirements. An energy storage power station system comprehensive efficiency optimization model is established and solved to obtain a comprehensive efficiency improvement strategy for the energy storage power station system, so as to improve the comprehensive efficiency of the energy storage power station system based on the strategy.

[0041] In one embodiment of the present invention, determining the comprehensive efficiency of the energy storage power station before optimization includes: obtaining the historical daily average on-grid power and the historical daily average off-grid power of the energy storage power station; and determining the comprehensive efficiency of the energy storage power station before optimization based on the historical daily average on-grid power and the historical daily average off-grid power of the energy storage power station.

[0042] It should be noted that the objective function of the comprehensive efficiency optimization model of the energy storage power station system is a function established with the minimum ΔP as the goal, and ΔP is the statistical value of the auxiliary load in the energy storage power station that is changed from self-power supply to station-powered power supply.

[0043] The constraints of the comprehensive efficiency optimization model of the energy storage power station system include: the start and end temperature constraints of the energy storage power station temperature control system stopping working, the power saving constraints after the energy storage power station temperature control system is optimized, the auxiliary load constraints of changing the self-power supply to the station power supply, and the comprehensive efficiency constraints of the energy storage power station.

[0044] ^

[0045] For ease of reading, the variable symbols in this embodiment are known quantities, such as given parameters,

[0046] ^Optimization results and values ​​of variables to be optimized. Those not included are unknown quantities, such as variables to be optimized, objective functions, etc.

[0047] Step 1: Obtain the information required for the comprehensive efficiency evaluation of the energy storage power station before optimization, including the historical daily average grid-connected power of the energy storage power station in the past year and daily average off-grid power consumption The unit is kWh.

[0048] Step 2: Obtain the comprehensive efficiency assessment value of the energy storage power station

[0049] Step 3: Obtain the start and end temperatures at which the temperature control system of the energy storage power station stops working before optimization Maximum allowable temperature difference of batteries in energy storage power stations The unit is °C. Get the rated power of the temperature control system of the energy storage power station The unit is kW.

[0050] Step 4: Build a thermal management simulation model for the energy storage system and obtain a list of daily average prefabricated cabin battery cell temperature statistics through simulation. The unit is hours, that is, the time when the temperature of the prefabricated cabin battery core is at 0℃ is hours, the time at 1°C is hours, the time at t℃ is Hour.

[0051] Step 5: Statistical value of the load supplied by self-use electricity in the auxiliary load of the energy storage power station before statistical optimization Statistical value of auxiliary load supplied by station transformer The unit is kW.

[0052] Step 6: Obtain the rated capacity of the station transformer The unit is kVA, the no-load loss of the station transformer The unit is kW, the load loss of the station transformer The unit is kW.

[0053] Step 7: Method for improving the overall efficiency of energy storage power station system:

[0054] Step 7.1, such as Figure 2 As shown, it is determined whether the comprehensive efficiency of the energy storage power station before optimization reaches the comprehensive efficiency assessment value. When expression (1) is established, the comprehensive efficiency of the energy storage power station meets the assessment requirements and no optimization is required. When expression (1) is not established, optimization is required and the process goes to step 7.2.

[0055]

[0056] Step 7.2, establish a comprehensive efficiency optimization model for the energy storage power station system, which aims to improve the comprehensive efficiency of the energy storage power station system at the minimum cost.

[0057] The objective function of the comprehensive efficiency optimization model of the energy storage power station system is as follows:

[0058] minΔP(2)

[0059] Among them, ΔP is the statistical value of the auxiliary load in the energy storage power station that is changed from self-power supply to station-use power supply, and the unit is kW.

[0060] The constraints of the comprehensive efficiency optimization model of the energy storage power station system include:

[0061] (1) The start and end temperature constraints for the temperature control system of the energy storage power station to stop working:

[0062]

[0063] Among them, T before , T end To optimize the starting and ending temperatures at which the temperature control system of the energy storage power station stops working, the unit is ℃.

[0064] Thus, the maximum allowable temperature difference of the energy storage power station battery can be obtained In order to base on the maximum allowable temperature difference of the battery in the energy storage power station Determine the start and end temperature constraints for the temperature control system of the energy storage power station to stop working.

[0065] (2) Constraints for power saving after optimization of the temperature control system of the energy storage power station:

[0066]

[0067] in, is the first Boolean variable, determined by formula (4), and is used to mark whether the temperature control system of the energy storage power station is working when the daily average prefabricated cabin battery core temperature before optimization is i°C.

[0068] b i It is the second Boolean variable, which is used to mark whether the temperature control system of the energy storage power station is working when the average daily prefabricated cabin battery cell temperature is i℃ after optimization.

[0069] ΔW wenkong It is the power saving constraint after optimizing the temperature control system of the energy storage power station, in kWh. It is the time when the temperature of the prefabricated cabin battery cell is at i℃.

[0070] Therefore, the starting and ending temperatures of the temperature control system of the energy storage power station before optimization can be used to stop working. Rated power of temperature control system of energy storage power station Daily average prefabricated cabin battery core temperature statistics duration list Determine the constraints for power saving after optimizing the temperature control system of the energy storage power station

[0071] (3) Auxiliary load constraints for changing self-use power supply to station power supply:

[0072] ΔP ≥ 0 (7)

[0073]

[0074] Therefore, the auxiliary load statistics of the station transformer power supply in the auxiliary load of the energy storage power station can be Rated capacity of station transformer Determine the auxiliary load constraints when changing from self-power supply to station power supply.

[0075] (4) Comprehensive efficiency constraints of energy storage power stations:

[0076]

[0077] Therefore, the no-load loss of the station transformer can be Load loss Rated capacity Historical daily average grid-connected power generation of energy storage power stations Historical daily average off-grid power consumption And the comprehensive efficiency assessment value Determine the comprehensive efficiency constraints of the energy storage power station.

[0078] Step 7.3, solve the energy storage power station system comprehensive efficiency optimization model described in step 7.2.

[0079] If there is no solution, it means that the comprehensive efficiency of the energy storage power station cannot be improved to the comprehensive efficiency assessment value without transformation.

[0080] If there is a solution, set the start and end temperatures of the energy storage power station temperature control system to stop working and will The self-powered supply is changed to auxiliary load supplied by station transformer.

[0081] in, T before 、T end , the solution value of ΔP.

[0082] Specifically, the comprehensive efficiency optimization model of the energy storage power station system can be solved to obtain the starting and ending temperatures of the temperature control system of the energy storage power station after optimization. Auxiliary load power when changing self-use power supply to station power supply Then set the start and end temperatures of the energy storage power station temperature control system to stop working as the start and end temperatures of the energy storage power station temperature control system to stop working after optimization And the corresponding auxiliary load power The auxiliary load is changed from self-power supply to station power supply.

[0083] As a specific example, a certain energy storage power station:

[0084] Historical daily average grid-connected power generation of energy storage power stations in the past year

[0085] Historical average daily off-grid electricity consumption of energy storage power stations in the past year

[0086] The comprehensive efficiency assessment value of the energy storage power station is

[0087] The start and end temperatures of the energy storage power station temperature control system before optimization

[0088] Maximum allowable temperature difference of batteries in energy storage power stations

[0089] Rated power of temperature control system of energy storage power station

[0090] Obtain the daily average prefabricated cabin battery core temperature statistics time through simulation: The duration of other temperature statistics is relatively short and has little impact on the optimization results, so they are not listed here.

[0091] Load statistics of auxiliary loads of energy storage power stations powered by self-power before optimization Statistical value of auxiliary load supplied by station transformer

[0092] Rated capacity of station transformer No-load loss of station transformer Station transformer load loss

[0093]

[0094] Implementation process

[0095] Step 1: Expression (1) is not satisfied, so the comprehensive efficiency of the energy storage power station needs to be optimized.

[0096] Steps 2 to 7: The energy storage power station system comprehensive efficiency optimization model has a solution. The start and end temperatures of the energy storage power station temperature control system are set to and will The self-powered supply is changed to the auxiliary load of the station transformer power supply. At this time, the comprehensive efficiency of the energy storage power station meets the assessment requirement of 0.85.

[0097] Furthermore, the present invention also provides a system for improving the comprehensive efficiency of an energy storage power station system, comprising a determination module, a judgment module, a construction module and a solution module connected in sequence, wherein the determination module is used to determine a comprehensive efficiency assessment value and the comprehensive efficiency of the energy storage power station before optimization; the judgment module is used to determine whether the comprehensive efficiency of the energy storage power station before optimization reaches the comprehensive efficiency assessment value; the construction module is used to establish a comprehensive efficiency optimization model for the energy storage power station system when the comprehensive efficiency of the energy storage power station before optimization does not reach the comprehensive efficiency assessment value; the solution module is used to solve the comprehensive efficiency optimization model for the energy storage power station system and obtain a comprehensive efficiency improvement strategy for the energy storage power station system, so as to achieve comprehensive efficiency optimization of the energy storage power station system.

[0098] It should be noted that the specific implementation of the system for improving the comprehensive efficiency of the energy storage power station system of this embodiment can refer to the specific implementation of the method for improving the comprehensive efficiency of the energy storage power station system described above, and will not be repeated here to avoid redundancy.

[0099] In summary, the present invention can evaluate whether the current comprehensive efficiency of the energy storage power station meets the assessment requirements; if it does not meet the assessment requirements, then a comprehensive efficiency optimization model for the energy storage power station system is established to determine whether the comprehensive efficiency of the energy storage power station can be improved to the assessment value without modification; if the comprehensive efficiency of the energy storage power station can be improved to the assessment value without modification, then a strategy for improving the comprehensive efficiency of the energy storage power station system with the lowest cost can be provided.

[0100] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0101] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

Claims

1. A method for improving the comprehensive efficiency of an energy storage power station system, characterized in that: include: Determine the comprehensive efficiency assessment value and the comprehensive efficiency of the energy storage power station before optimization; Determine whether the comprehensive efficiency of the energy storage power station before optimization reaches the comprehensive efficiency assessment value; When the comprehensive efficiency of the energy storage power station before optimization does not reach the comprehensive efficiency assessment value, establishing a comprehensive efficiency optimization model for the energy storage power station system; Solve the comprehensive efficiency optimization model of the energy storage power station system to obtain a comprehensive efficiency improvement strategy for the energy storage power station system, so as to achieve comprehensive efficiency optimization of the energy storage power station system.

2. The method for improving the comprehensive efficiency of the energy storage power station system according to claim 1, characterized in that: Determine the overall efficiency of the energy storage plant before optimization, including: Obtain the historical daily average on-grid power and historical daily average off-grid power of the energy storage power station; The comprehensive efficiency of the energy storage power station before optimization is determined based on the historical average daily grid-connected power and historical average daily grid-offline power of the energy storage power station.

3. The method for improving the comprehensive efficiency of the energy storage power station system according to claim 2, characterized in that: The objective function of the comprehensive efficiency optimization model of the energy storage power station system is a function established with the minimum ΔP as the goal, and ΔP is the statistical value of the auxiliary load in the energy storage power station that is changed from self-power supply to station-powered power supply.

4. The method for improving the comprehensive efficiency of the energy storage power station system according to claim 2, characterized in that: The constraints of the comprehensive efficiency optimization model of the energy storage power station system include: the start and end temperature constraints of the energy storage power station temperature control system stopping working, the power saving constraints after the energy storage power station temperature control system is optimized, the auxiliary load constraints of changing the self-power supply to the station power supply, and the comprehensive efficiency constraints of the energy storage power station.

5. The method for improving the comprehensive efficiency of the energy storage power station system according to claim 4, characterized in that: The maximum allowable temperature difference of the battery of the energy storage power station is obtained, so as to determine the start and end temperature constraint conditions for stopping the operation of the temperature control system of the energy storage power station based on the maximum allowable temperature difference of the battery of the energy storage power station.

6. The method for improving the comprehensive efficiency of the energy storage power station system according to claim 4, characterized in that: Obtain the start and end temperatures at which the temperature control system of the energy storage power station stops working, the rated power of the temperature control system of the energy storage power station, and the daily average prefabricated cabin battery cell temperature statistical duration list before optimization, so as to determine the power saving constraint conditions after the temperature control system of the energy storage power station is optimized.

7. The method for improving the comprehensive efficiency of the energy storage power station system according to claim 4, characterized in that: Obtain the auxiliary load statistics of the station transformer power supply and the rated capacity of the station transformer in the auxiliary load of the energy storage power station, so as to determine the auxiliary load constraint conditions for changing the self-power supply to the station transformer power supply.

8. The method for improving the comprehensive efficiency of the energy storage power station system according to claim 7, characterized in that: The no-load loss and load loss of the station transformer are obtained in order to determine the comprehensive efficiency constraints of the energy storage power station based on the no-load loss, load loss, rated capacity, historical daily average on-grid power and historical daily average off-grid power of the energy storage power station, and the comprehensive efficiency assessment value.

9. The method for improving the comprehensive efficiency of the energy storage power station system according to claim 1, characterized in that: Solving the comprehensive efficiency optimization model of the energy storage power station system to obtain the starting and ending temperatures of the temperature control system of the energy storage power station after optimization and the auxiliary load power of the self-power supply changed to the station-powered power supply, the comprehensive efficiency improvement strategy of the energy storage power station system is: The start and end temperatures at which the temperature control system of the energy storage power station stops working are set to the start and end temperatures at which the temperature control system of the energy storage power station stops working after optimization, and the auxiliary load corresponding to the auxiliary load power is changed from self-power supply to station-powered transformer power supply.

10. A system for improving the comprehensive efficiency of an energy storage power station system, characterized in that: include: A determination module, used to determine the comprehensive efficiency assessment value and the comprehensive efficiency of the energy storage power station before optimization; A judgment module, used to judge whether the comprehensive efficiency of the energy storage power station before optimization reaches the comprehensive efficiency assessment value; A construction module is used to establish a comprehensive efficiency optimization model of the energy storage power station system when the comprehensive efficiency of the energy storage power station before optimization does not reach the comprehensive efficiency assessment value; The solution module is used to solve the comprehensive efficiency optimization model of the energy storage power station system and obtain a comprehensive efficiency improvement strategy for the energy storage power station system, so as to achieve comprehensive efficiency optimization of the energy storage power station system.

Images