Optimal configuration method and equipment for optical storage substitution transformation of diesel generator off-network system

Abstract

The invention relates to an electric power system optimization technology, in particular to a diesel generator off-network system optical storage replacement transformation optimization configuration method and device, and the method comprises the steps: initializing system parameters: inputting time sequence data, setting technical parameters, and defining parameters; constructing a light-storage-diesel joint optimization model, including defining decision variables and establishing an objective function which is used for minimizing the comprehensive cost in an operation and maintenance period, and setting photovoltaic operation constraint conditions, including photovoltaic power generation capacity constraint considering capacity attenuation and energy storage operation constraint condition setting; comprising an energy storage real-time capacity charge state constraint considering capacity attenuation, an energy storage real-time power constraint considering capacity attenuation and a constraint between energy storage real-time power and real-time capacity, and an off-grid system power supply reliability constraint is set; and rapidly solving the constructed light-storage-diesel joint optimization model based on dynamic capacity iteration. According to the method, high-economy and low-pollution renewable energy source replacement is realized through collaborative optimization configuration of photovoltaic, energy storage and diesel generators.

Description

Technical Field

[0001] The present invention belongs to the technical field of power system optimization, and in particular relates to a method and device for optimizing the configuration of a photovoltaic-storage replacement transformation of an off-grid diesel generator system. Background Art

[0002] Traditional off-grid systems rely primarily on diesel generators for power, which presents challenges such as high fuel costs and severe environmental pollution. In recent years, the introduction of photovoltaic and energy storage technologies has made green transformation possible for off-grid systems, but existing technologies have the following limitations: 1) Inadequate modeling of equipment degradation: Existing solutions ignore the annual capacity degradation effects of photovoltaics and energy storage (e.g., 0.4% annual degradation for photovoltaics and 2% annual degradation for energy storage), leading to deviations in the estimation of the full life cycle cost.

[0003] 2) Excessive dependence on diesel: Traditional methods have not effectively balanced the synergy between photovoltaics, energy storage and diesel power generation, and the diesel substitution rate is low (usually <30%), which cannot fully tap the potential of renewable energy. Summary of the Invention

[0004] The present invention provides a method and equipment for optimizing the configuration of photovoltaic storage replacement transformation in an off-grid diesel generator system, which is used to solve the defects of the existing technology that the attenuation of the off-grid diesel generator system equipment is not fully modeled and the dependence on diesel is too high, and realizes highly economical and low-pollution renewable energy replacement.

[0005] The variable symbols appearing in the present invention are marked with are known quantities, such as given parameters, optimization results, and values of variables to be optimized. are unknown quantities, such as variables to be optimized, objective functions, etc. The currency unit appearing in the present invention is RMB, hereinafter referred to as RMB.

[0006] The present invention provides a method for optimizing the configuration of a photovoltaic-storage replacement system for an off-grid diesel generator system, comprising: Step 1. System parameter initialization: including inputting time series data, setting technical parameters and defining parameters; Step 2. Construct a solar-storage-diesel joint optimization model; Step 3. Rapidly solve the constructed solar-storage-diesel joint optimization model based on dynamic capacity iteration.

[0007] According to the present invention, a method for optimizing the configuration of a photovoltaic-storage replacement system for an off-grid diesel generator system is provided. The specific steps for initializing the system parameters are as follows: Step 1.1. Input 8760 hours of time series data, including: , the power that can be generated by a 100MW photovoltaic power generation unit at time t is calculated by photovoltaic calculation simulation software based on local light resource conditions, in MW; is the load demand at time t, in MW; Step 1.2. Set technical parameters, including: , annual attenuation rate of photovoltaic capacity; , annual attenuation rate of energy storage capacity; , initial value of state of charge; , minimum state of charge; , maximum state of charge; , energy storage rated charge and discharge rate; , energy storage discharge efficiency; , energy storage charging efficiency; , the maximum power of existing diesel generators, in MW; , the amount of electricity generated per liter of diesel, in kWh; , operation and maintenance period in years.

[0008] Step 1.3. Define economic parameters, including: , PV investment cost, unit is yuan / MWp; , PV operation and maintenance cost, unit is RMB / MWp / year; , energy storage investment cost, unit is RMB / MWh; , energy storage operation and maintenance cost, unit is RMB / MWh / year; , diesel cost, unit is yuan / liter.

[0009] According to the present invention, a method for optimizing the configuration of a photovoltaic-storage replacement system for an off-grid diesel generator system is provided. The method of constructing a photovoltaic-storage-diesel combined optimization model includes: Step 2.1. Define the decision variables: is the photovoltaic capacity configuration value, in MWp; The energy storage capacity configuration value is in MWh; is the output power of the diesel generator at time t, in MW; Step 2.2. Establish the objective function, which is to minimize the comprehensive cost during the operation and maintenance period: (1.1) in: is the comprehensive cost, unit is RMB; Step 2.3. Set the photovoltaic operation constraints, including the photovoltaic power generation constraints considering capacity degradation. The specific expressions are as follows: (1.2) in: is the photovoltaic power that can be generated at time t, in MW; Step 2.4. Set energy storage operation constraints, including energy storage real-time capacity state of charge constraints considering capacity decay, energy storage real-time power constraints considering capacity decay, and constraints between energy storage real-time power and real-time capacity; Step 2.5. Set the off-grid system power supply reliability constraint, that is, the sum of the output of photovoltaic, energy storage, and diesel generators at each moment must be no less than the load: (1.11).

[0010] According to the method for optimizing the configuration of photovoltaic-storage replacement transformation for an off-grid diesel generator system provided by the present invention, the energy storage operation constraint conditions in step 2.4 are specifically expressed as follows: Step 2.4.1. Real-time capacity state of charge constraint of energy storage considering capacity decay: (1.3) (1.4) (1.5) in: is the real-time capacity of energy storage at time t, in MWh. When t is 0, it is the initial time. At this time, the state of charge satisfies the initial state, i.e., equation (1.3). When t is 8760, it is the final state. In this model, it is assumed that the final state of charge is equal to the initial state of charge. Step 2.4.2. Consider the real-time power constraint of energy storage with capacity decay: (1.6) in: The real-time power of energy storage at time t, when it is greater than 0, it is discharging, and when it is less than 0, it is charging, the unit is MW; Step 2.4.3. Constraints between real-time power and real-time capacity of energy storage: (1.7) (1.8) (1.9) (1.10).

[0011] According to the present invention, a method for optimizing the configuration of a photovoltaic-storage replacement system for an off-grid diesel generator system is provided. The steps of constructing a photovoltaic-storage-diesel joint optimization model based on dynamic capacity iterative rapid solution are as follows: Step 3.1. Based on the capacity of the energy storage basic unit and the 8760-hour load demand, set the initial value of the energy storage capacity according to the total load of approximately 2 days: (1.12) in: is the ceiling function; is the basic unit capacity of energy storage, in MWh; is the initial value of energy storage capacity, in MWh; Step 3.2. Iterative search quickly finds the interval where the optimal solution of the solar-storage-diesel joint optimization model is located, and the energy storage capacity setting value at the kth iteration is , the energy storage capacity setting value in the first iteration is the initial value of the energy storage capacity obtained in step 3.1 ; Step 3.3. Perform an accurate search based on the interval obtained in step 3.2, and calculate the energy storage capacity setting value at the kth iteration as , the energy storage capacity setting value at the first iteration As the starting point of the search range obtained in step 3.2, the energy storage capacity is set to the minimum value This is the end point of the search range obtained in step 3.2.

[0012] According to the method for optimizing the configuration of a photovoltaic-storage replacement system for an off-grid diesel generator system provided by the present invention, the specific steps of the iterative search in step 3.2 to quickly find the interval where the optimal solution of the photovoltaic-storage-diesel combined optimization model is located are as follows: Step 3.2.1. Due to the energy storage capacity configuration value This decision variable has been assigned The solar-storage-diesel joint optimization model built in step 2 is also simplified into a solar-storage-diesel joint optimization fast solution model, and the objective function of this model is: (1.13) The constraints of the model are: (1.14) (1.15) (1.16) (1.17) (1.18) (1.19) (1.20) (1.21) (1.22); Step 3.2.2. Use the Big M method to handle the nonlinear constraints in the rapid solution model of the energy storage capacity joint optimization of photovoltaic storage and diesel, namely, the constraint formula (1.18) - constraint formula (1.21) between the real-time power and real-time capacity of the energy storage, and solve the model to obtain the solution value of photovoltaic capacity, the solution value of diesel generator, and the solution value of comprehensive cost. The specific steps are as follows: Step 3.2.2.1. Define 8760 0-1 variables , t∈[1,8760]; Step 3.2.2.2. Define a large number ; Step 3.2.2.3. Rewrite the constraint equation (1.18) - constraint equation (1.21) between the real-time power and real-time capacity of the energy storage in the energy storage capacity fast solution model into the following constraint: (1.23) (1.24) (1.25) (1.26) (1.27) (1.28) (1.29) (1.30) (1.31) (1.32); Step 3.2.2.4, solve the energy storage capacity fast solution model, the objective function is formula (1.13), the constraints are formula (1.14)-formula (1.17), formula (1.22)-formula (1.32), and the photovoltaic capacity solution is obtained 、Calculation of diesel generator output power for 8760 hours , comprehensive cost solution value ; Step 3.2.2.5. Diesel generator solution The maximum value of the diesel generator's output power for 8760 hours is: (1.33); Step 3.2.3. If and When , the energy storage configuration value in the optimal solution of the solar-storage-diesel joint optimization model is at the starting point , the end point is If the search range is not satisfied, it means that the search range of the optimal solution has not been found. , the search end point has not been reached. , repeat step 3.2.2; if The search end point has been reached, and the energy storage configuration value is at the starting point of the interval , the end point is In the search range, go to step 3.3.

[0013] According to the present invention, a method for optimizing the configuration of a photovoltaic storage replacement system for an off-grid diesel generator system is implemented as follows: performing an accurate search based on the interval obtained in step 3.2.3, and calculating the energy storage capacity setting value at the kth iteration. , the energy storage capacity setting value at the first iteration As the starting point of the search range obtained in step 3.2.3, the energy storage capacity is set to the minimum value The end point of the search range obtained in step 3.2.3; the specific steps are as follows: Step 3.3.1, due to the energy storage capacity configuration value This decision variable has been assigned Therefore, the solar-storage-diesel joint optimization model built in step 2 is also simplified to a solar-storage-diesel joint optimization fast solution model, and the objective function of this model is: (1.35) The constraints of the model are: (1.36) (1.37) (1.38) (1.39) (1.40) (1.41) (1.42) (1.43) (1.44); Step 3.3.2. Use the Big M method to address the nonlinear constraints in the rapid solution model for the combined optimization of solar-storage-diesel energy storage capacity, namely, constraints (3.3.5) to (3.3.9) between the real-time power and capacity of the energy storage. Solve the model to obtain the solution values for the PV capacity, diesel generator, and comprehensive cost. The specific steps are as follows: Step 3.3.2.1. Define 8760 0-1 variables , t∈[1,8760]; Step 3.3.2.2. Define a large number ; Step 3.3.2.3. Rewrite the constraints (3.3.6)-(3.3.9) between the real-time power and real-time capacity of the energy storage in the energy storage capacity fast solution model into the following constraints: (1.45) (1.46) (1.47) (1.48) (1.49) (1.50) (1.51) (1.52) (1.53) (1.54) Step 3.3.2.4. Solve the energy storage capacity fast solution model. The objective function is Equation (1.35), and the constraints are Equations (1.36)-(1.39), (1.44)-(1.54). The photovoltaic capacity solution is obtained. 、Calculation of diesel generator output power for 8760 hours , comprehensive cost solution value ; Step 3.3.2.5. Diesel generator solution The maximum value of the diesel generator's output power for 8760 hours is: (1.55); Step 3.3.3. If and When , the energy storage configuration value in the optimal solution of the solar-storage-diesel joint optimization model is for , PV configuration value for , diesel generator capacity configuration value for If it is not satisfied, it means that the optimal solution has not been found. , the search end point has not been reached. , repeat step 3.3.2; if The search endpoint has been reached, and the energy storage configuration value in the optimal solution of the photovoltaic, storage and diesel joint optimization model is , PV configuration value for , diesel generator capacity configuration value for .

[0014] The present invention also provides an electronic device, including a memory, a processor and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the method for optimizing the configuration of the photovoltaic storage replacement transformation of the diesel-generator off-grid system.

[0015] The present invention also provides a computer-readable storage medium having a computer program / instruction stored thereon, which, when executed by a processor, implements the steps of the method for optimizing the configuration of the photovoltaic-storage replacement transformation of an off-grid diesel generator system.

[0016] The present invention also provides a computer program product, including a computer program / instruction, which, when executed by a processor, implements the steps of the method for optimizing the configuration of the photovoltaic storage replacement transformation of an off-grid diesel generator system.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. Improved computational efficiency: A two-stage search strategy (large step jumps in the exploration phase + gradient acceleration in the refinement phase) reduces the number of calculations by 75% (from 200 to 50 in the example), shortening the computation time from several hours to 165 seconds. The introduction of the large-M method to linearize nonlinear constraints, Equations (1.23) to (1.32), reduces the model solution time by 40% (a single solution time of <4 seconds in the example).

[0018] 2. Significantly reduced overall costs: By accurately locating the extreme point through dynamic capacity iteration, the lowest overall cost in this embodiment is RMB 478,102.29 million, a 12.3% reduction compared to traditional methods.

[0019] 3) Long-term reliability assurance: Detailed modeling of the annual degradation effect of photovoltaic / energy storage, using equations (1.2), (1.4), and (1.6), ensures power supply reliability >99.5% within the 20-year operation and maintenance period.

[0020] 4) Robustness and Scalability: Supports discretized constraints on energy storage capacity (integer multiples of 5MWh) to adapt to the actual procurement needs of the project; the algorithm adaptively adjusts the step size, that is, step 3.2.3 can be expanded to collaborative optimization scenarios of multiple energy types (such as wind power and hydrogen energy). BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 It is a structural diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0023] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0024] This embodiment provides a method for optimizing the configuration of photovoltaic and energy storage replacement in an off-grid diesel generator system. The method is applicable to off-grid power supply systems in remote areas that rely on diesel power generation. Through the coordinated optimization configuration of photovoltaics, energy storage and diesel generators, a highly economical and low-pollution renewable energy replacement is achieved.

[0025] This embodiment aims to solve the following technical problems encountered in optimizing the configuration of solar-storage replacement transformation in off-grid diesel generator systems: 1) Computational efficiency bottleneck: Traditional enumeration methods require traversing hundreds of energy storage capacity points, which takes too long to calculate (for example, 200 solutions take several hours), making it difficult to meet the needs of rapid decision-making in actual engineering projects.

[0026] 2) Long-term economic bias: Failure to consider equipment degradation, which results in annual capacity decline, leads to an error of more than 15% in the estimated life cycle cost.

[0027] 3) Difficulty in solving complex constraints: The nonlinear constraints of energy storage charging and discharging power and capacity attenuation make the model difficult to converge, but easy to solve.

[0028] This embodiment is implemented through the following technical solutions: a method for optimizing the configuration of a solar-storage replacement system for an off-grid diesel generator system, including the following steps: S1. System parameter initialization; S1.1. Input 8760 hours of time series data, including: , the power that can be generated by a 100MW photovoltaic power generation unit at time t is calculated by photovoltaic calculation simulation software based on local light resource conditions, in MW; is the load demand at time t, in MW.

[0029] S1.2. Set technical parameters, including: , annual attenuation rate of photovoltaic capacity; , annual attenuation rate of energy storage capacity; , initial value of state of charge; , minimum state of charge; , maximum state of charge; , energy storage rated charge and discharge rate; , energy storage discharge efficiency; , energy storage charging efficiency; , the maximum power of existing diesel generators, in MW; , the amount of electricity generated per liter of diesel, in kWh; , operation and maintenance period in years.

[0030] S1.3. Define economic parameters, including: , PV investment cost, unit is yuan / MWp; , PV operation and maintenance cost, unit is RMB / MWp / year; , energy storage investment cost, unit is RMB / MWh; , energy storage operation and maintenance cost, unit is RMB / MWh / year.

[0031] , diesel cost, unit is yuan / liter.

[0032] S2. Construct a solar-storage-diesel joint optimization model.

[0033] S2.1. Define decision variables: is the photovoltaic capacity configuration value, in MWp; The energy storage capacity configuration value is in MWh; is the output power of the diesel generator at time t, in MW; S 2.2. Establish an objective function, which is to minimize the comprehensive cost during the operation and maintenance period: (1.1) in: is the comprehensive cost, unit is yuan.

[0034] S2.3. Set PV operation constraints, including PV power generation constraints that take into account capacity degradation. Specific expressions are as follows: (1.2) in: is the photovoltaic power that can be generated at time t, in MW.

[0035] S2.4. Set energy storage operation constraints, including energy storage real-time capacity state of charge constraints considering capacity decay, energy storage real-time power constraints considering capacity decay, and constraints between energy storage real-time power and real-time capacity. Specific expressions are as follows: S 2.4.1. Real-time capacity state of charge constraints for energy storage considering capacity decay: (1.3) (1.4) (1.5) in: is the real-time capacity of energy storage at time t, in MWh. When t is 0, it is the initial time. At this time, the state of charge satisfies the initial state, i.e., equation (1.3). When t is 8760, it is the final state. In this model, it is assumed that the final state of charge is equal to the initial state of charge. S 2.4.2. Real-time power constraints of energy storage considering capacity decay: (1.6) in: The real-time power of energy storage at time t (greater than 0 for discharging, less than 0 for charging), in MW; S 2.4.3. Constraints between real-time power and real-time capacity of energy storage: (1.7) (1.8) (1.9) (1.10) S2.5. Set off-grid system power supply reliability constraints, that is, the sum of the output of photovoltaic, energy storage, and diesel generators at each moment must be no less than the load: (1.11) S3. Rapidly solve the solar-storage-diesel joint optimization model constructed in step 2 based on dynamic capacity iteration.

[0036] S 3.1. Based on the capacity of the energy storage basic unit and the 8760-hour load demand, set the initial value of the energy storage capacity according to the total load of approximately 2 days: (1.12) in: is the ceiling function; is the basic unit capacity of energy storage, in MWh; It is the initial value of energy storage capacity, in MWh.

[0037] S3.2, iterative search quickly finds the interval where the optimal solution of the solar-storage-diesel joint optimization model is located, and the energy storage capacity setting value at the kth iteration is (The energy storage capacity setting value in the first iteration is the initial value of the energy storage capacity obtained in step 3.1 ): S3.2.1, due to the energy storage capacity configuration value This decision variable has been assigned Therefore, the solar-storage-diesel joint optimization model built in S2 is also simplified to a solar-storage-diesel joint optimization fast solution model, and the objective function of this model is: (1.13) The constraints of the model are: (1.14) (1.15) (1.16) (1.17) (1.18) (1.19) (1.20) (1.21) (1.22); For a description of the model parameters, see S2.

[0038] S3.2.2. Use the Big M method to handle the nonlinear constraints in the rapid solution model for the combined optimization of solar-storage-diesel energy storage capacity, namely the constraints (1.18)-(1.21) between the real-time power and capacity of the energy storage. Solve the model to obtain the solution values for the photovoltaic capacity, diesel generator, and comprehensive cost. The specific steps are as follows: S3.2.2.1. Define 8760 0-1 variables , t∈[1,8760].

[0039] S.2.2.2 Defining a large number .

[0040] S.2.2.3. Rewrite the constraints (1.18)-(1.21) between the real-time power and real-time capacity of the energy storage in the energy storage capacity fast solution model as follows: (1.23) (1.24) (1.25) (1.26) (1.27) (1.28) (1.29) (1.30) (1.31) (1.32); S3.2.2.4. Solve the energy storage capacity fast solution model. The objective function is equation (1.13), and the constraints are equations (1.14)-(1.17), (1.22-1.32). The photovoltaic capacity solution is obtained. 、Calculation of diesel generator output power for 8760 hours , comprehensive cost solution value .

[0041] S3.2.2.5. Solution value of oil generator The maximum value of the diesel generator's output power for 8760 hours is (1.33) S3.2.3. If and When , it means that the energy storage configuration value in the optimal solution of the solar-storage-diesel joint optimization model is at the starting point , the end point is If the search range is not satisfied, it means that the search range of the optimal solution has not been found. , it means that the search end point has not been reached. , re-execute S 3.2.2; if This means that the search end point has been reached and the energy storage configuration value is at the starting point of the interval. , the end point is In the search range, enter S3.3.

[0042] S3.3. Based on the interval obtained in S3.2.3, perform an accurate search and calculate the energy storage capacity setting value at the kth iteration , the energy storage capacity setting value at the first iteration Set the minimum value for the energy storage capacity as the starting point of the search range obtained in S3.2.3 This is the end point of the search range obtained in S3.2.3.

[0043] S 3.3.1. Due to the energy storage capacity configuration value This decision variable has been assigned Therefore, the solar-storage-diesel joint optimization model built in S2 is also simplified to a solar-storage-diesel joint optimization fast solution model, and the objective function of this model is: (1.35) The constraints of the model are: (1.36) (1.37) (1.38) (1.39) (1.40) (1.41) (1.42) (1.43) (1.44); For a description of the model parameters, see S2.

[0044] S3.3.2. Use the Big M method to address the nonlinear constraints in the rapid solution model for the combined optimization of solar-storage-diesel energy storage capacity, namely the constraints (1.40)-(1.43) between the real-time power and capacity of the energy storage. Solve the model to obtain the solution values for the photovoltaic capacity, diesel generator, and comprehensive cost. The specific steps are as follows: S3.3.2.1, define 8760 0-1 variables , t∈[1,8760].

[0045] S3.3.2.2, Define a Large Number .

[0046] S3.3.2.3, rewrite the constraints (1.40)-(1.43) between the real-time power and real-time capacity of the energy storage in the energy storage capacity fast solution model into the following constraints: (1.45) (1.46) (1.47) (1.48) (1.49) (1.50) (1.51) (1.52) (1.53) (1.54); S3.3.2.4. Solve the energy storage capacity fast solution model. The objective function is equation (1.35), and the constraints are equations (1.36)-(1.39), (1.44-1.54). The photovoltaic capacity solution is obtained. 、Calculation of diesel generator output power for 8760 hours , comprehensive cost solution value .

[0047] S3.3.2.5. Solution value for diesel generator The maximum value of the diesel generator's output power for 8760 hours is (1.55); S3.3.3. If and When , it means that the energy storage configuration value in the optimal solution of the solar-storage-diesel joint optimization model is for , PV configuration value for , diesel generator capacity configuration value for If it is not satisfied, it means that the optimal solution has not been found. , it means that the search end point has not been reached. , re-execute S3.3.2; if This means that the search endpoint has been reached, and the energy storage configuration value in the optimal solution of the photovoltaic, storage and diesel joint optimization model is , PV configuration value for , diesel generator capacity configuration value for .

[0048] Thus, the present invention has completed the optimization configuration of the photovoltaic storage replacement transformation of the diesel-generator off-grid system based on dynamic capacity iteration.

[0049] Example 1. Description of the Example The photovoltaic investment cost is 3,640,000 yuan / MWp.

[0050] The photovoltaic operation and maintenance cost is 28,700 yuan / MWp / year.

[0051] The energy storage investment cost is 2,100,000 yuan / MWh.

[0052] The energy storage operation and maintenance cost is 42,000 yuan / MWh / year.

[0053] The basic energy storage unit capacity is 5MWh.

[0054] The power generated by a 100MW photovoltaic power generation unit is a list of length 8760, which is not shown here.

[0055] The annual degradation rate of photovoltaic capacity is 0.4%.

[0056] The annual decay rate of energy storage capacity is 2%.

[0057] The initial state of charge is 0.35.

[0058] The minimum state of charge is 0.05.

[0059] The maximum state of charge is 0.95.

[0060] The rated charge and discharge rate of energy storage is 0.5.

[0061] The energy storage discharge efficiency is 0.93.

[0062] The energy storage charging efficiency is 0.93.

[0063] The operation and maintenance years are 20.

[0064] The price of diesel is 5.25 yuan per liter.

[0065] The diesel generator fuel consumption is 2.76kWh / liter.

[0066] 2. Implementation process Through S3.1, the initial configuration value of energy storage capacity is 1500MWh.

[0067] Through S3.2, the PV solution values, energy storage configuration values, diesel generation configuration values, and comprehensive costs under different PV capacity configuration values are obtained, as shown in the table below. The starting value of the energy storage configuration value search range is determined to be 780MWh and the ending value is determined to be 620MWh.

[0068]

[0069] Through S3.3, the PV solution values, energy storage configuration values, diesel generation configuration values, and comprehensive costs under different PV capacity configuration values were obtained, as shown in the table below. The energy storage configuration value was determined to be 660MWh.

[0070]

[0071] The above steps took a total of 165 seconds, which is significantly shorter than running the model built in step 2 directly.

[0072] Figure 1 An example of a physical structure diagram of an electronic device is shown below. Figure 1 As shown, the electronic device may include a processor, a communications interface, a memory, and a communications bus. The processor, the communications interface, and the memory communicate with each other via the communications bus. The processor may invoke logic instructions in the memory to execute the method for optimizing the configuration of a solar-to-storage replacement system for an off-grid diesel generator system.

[0073] Furthermore, the logical instructions in the aforementioned memory can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the portion that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage media include various media capable of storing program code, such as USB flash drives, mobile hard drives, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical disks.

[0074] On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the optimization configuration method for the photovoltaic storage replacement transformation of the diesel-generated off-grid system provided by the above methods.

[0075] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the methods for optimizing the configuration of the photovoltaic-storage replacement transformation of an off-grid diesel generator system provided by the above methods.

[0076] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0077] Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented using software plus a necessary general-purpose hardware platform, or of course, hardware. Based on this understanding, the essence of the above technical solution, or the portion that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, or an optical disk, and includes a number of instructions for causing a computer device (such as a personal computer, server, or network device) to execute the methods described in each embodiment or certain portions of the embodiments.

[0078] 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 aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for optimizing the configuration of a diesel-to-electric off-grid system with photovoltaic and energy storage replacement, characterized in that: The following steps are involved: Step 1. System parameter initialization: including inputting time series data, setting technical parameters and defining parameters; Step 2. Construct a solar-storage-diesel joint optimization model; Step 3. Rapidly solve the constructed solar-storage-diesel joint optimization model based on dynamic capacity iteration.

2. The method for optimizing the configuration of the off-grid diesel generator system with solar-storage replacement according to claim 1 is characterized in that: The specific steps of initializing the system parameters are as follows: Step 1.

1. Input 8760 hours of time series data, including: , the power that can be generated by a 100MW photovoltaic power generation unit at time t is calculated by photovoltaic calculation simulation software based on local light resource conditions, in MW; is the load demand at time t, in MW; Step 1.

2. Set technical parameters, including: , annual attenuation rate of photovoltaic capacity; , annual attenuation rate of energy storage capacity; , initial value of state of charge; , minimum state of charge; , maximum state of charge; , energy storage rated charge and discharge rate; , energy storage discharge efficiency; , energy storage charging efficiency; , the maximum power of existing diesel generators, in MW; , the amount of electricity generated per liter of diesel, in kWh; , operation and maintenance period in years. Step 1.

3. Define economic parameters, including: , PV investment cost, unit is yuan / MWp; , PV operation and maintenance cost, unit is RMB / MWp / year; , energy storage investment cost, unit is RMB / MWh; , energy storage operation and maintenance cost, unit is RMB / MWh / year; , diesel cost, unit is yuan / liter.

3. The method for optimizing the configuration of the off-grid diesel generator system with solar-storage replacement according to claim 1 is characterized in that: The construction of the photovoltaic, energy storage and diesel joint optimization model includes: Step 2.

1. Define the decision variables: is the photovoltaic capacity configuration value, in MWp; The energy storage capacity configuration value is in MWh; is the output power of the diesel generator at time t, in MW; Step 2.

2. Establish the objective function, which is to minimize the comprehensive cost during the operation and maintenance period: （1.1） in: is the comprehensive cost, unit is RMB; Step 2.

3. Set the photovoltaic operation constraints, including the photovoltaic power generation constraints considering capacity degradation. The specific expressions are as follows: （1.2） in: is the photovoltaic power that can be generated at time t, in MW; Step 2.

4. Set energy storage operation constraints, including energy storage real-time capacity state of charge constraints considering capacity decay, energy storage real-time power constraints considering capacity decay, and constraints between energy storage real-time power and real-time capacity; Step 2.

5. Set the off-grid system power supply reliability constraint, that is, the sum of the output of photovoltaic, energy storage, and diesel generators at each moment must be no less than the load: （1.11）。 4. The method for optimizing the configuration of the off-grid diesel generator system with solar-storage replacement according to claim 3 is characterized in that: The energy storage operation constraints in step 2.4 are specifically stated as follows: Step 2.4.

1. Real-time capacity state of charge constraint of energy storage considering capacity decay: （1.3） （1.4） （1.5） in: is the real-time capacity of energy storage at time t, in MWh. When t is 0, it is the initial time. At this time, the state of charge satisfies the initial state, i.e., equation (1.3). When t is 8760, it is the final state. In this model, it is assumed that the final state of charge is equal to the initial state of charge. Step 2.4.

2. Consider the real-time power constraint of energy storage with capacity decay: （1.6） in: The real-time power of energy storage at time t, when it is greater than 0, it is discharging, and when it is less than 0, it is charging, the unit is MW; Step 2.4.

3. Constraints between real-time power and real-time capacity of energy storage: （1.7） （1.8） （1.9） （1.10）。 5. The method for optimizing configuration of off-grid diesel generator system with solar-storage replacement according to claim 1 is characterized in that: The steps of constructing the solar-storage-diesel joint optimization model based on dynamic capacity iterative rapid solution are as follows: Step 3.

1. Based on the capacity of the energy storage basic unit and the 8760-hour load demand, set the initial value of the energy storage capacity according to the total load of approximately 2 days: （1.12） in: is the ceiling function; is the basic unit capacity of energy storage, in MWh; is the initial value of energy storage capacity, in MWh; Step 3.

2. Iterative search quickly finds the interval where the optimal solution of the solar-storage-diesel joint optimization model is located, and the energy storage capacity setting value at the kth iteration is , the energy storage capacity setting value in the first iteration is the initial value of the energy storage capacity obtained in step 3.1 ; Step 3.

3. Perform an accurate search based on the interval obtained in step 3.2, and calculate the energy storage capacity setting value at the kth iteration as , the energy storage capacity setting value at the first iteration As the starting point of the search range obtained in step 3.2, the energy storage capacity is set to the minimum value This is the end point of the search range obtained in step 3.

2.

6. The method for optimizing configuration of off-grid diesel generator system with solar-storage replacement according to claim 5 is characterized in that: The specific steps for the iterative search in step 3.2 to quickly find the interval where the optimal solution of the solar-storage-diesel combined optimization model is located are as follows: Step 3.2.

1. Due to the energy storage capacity configuration value This decision variable has been assigned The solar-storage-diesel joint optimization model built in step 2 is simplified to a solar-storage-diesel joint optimization fast solution model, and the objective function of this model is: （1.13） The constraints of the model are: （1.14） （1.15） （1.16） （1.17） （1.18） （1.19） （1.20） （1.21） （1.22）； Step 3.2.

2. Use the Big M method to handle the nonlinear constraints in the rapid solution model of the energy storage capacity joint optimization of photovoltaic storage and diesel, namely, the constraint formula (1.18) - constraint formula (1.21) between the real-time power and real-time capacity of the energy storage, and solve the model to obtain the solution value of photovoltaic capacity, the solution value of diesel generator, and the solution value of comprehensive cost. The specific steps are as follows: Step 3.2.2.

1. Define 8760 0-1 variables , t∈[1,8760]; Step 3.2.2.

2. Define a large number ; Step 3.2.2.

3. Rewrite the constraints (3.2.6) and (3.2.9) between the real-time power and real-time capacity of the energy storage in the energy storage capacity rapid solution model into the following constraints: （1.23） （1.24） （1.25） （1.26） （1.27） （1.28） （1.29） （1.30） （1.31） （1.32）； Step 3.2.2.4, solve the energy storage capacity fast solution model, the objective function is formula (1.13), the constraints are formula (1.14)-formula (1.17), formula (1.22)-formula (1.32), and the photovoltaic capacity solution is obtained 、Calculation of diesel generator output power for 8760 hours , comprehensive cost solution value ; Step 3.2.2.

5. Diesel generator solution The maximum value of the diesel generator's output power for 8760 hours is: （1.33）； Step 3.2.

3. If and When , the energy storage configuration value in the optimal solution of the solar-storage-diesel joint optimization model is at the starting point , the end point is If the search range is not satisfied, it means that the search range of the optimal solution has not been found. , the search end point has not been reached. , repeat step 3.2.2; if The search end point has been reached, and the energy storage configuration value is at the starting point of the interval , the end point is In the search range, go to step 3.

3.

7. The method for optimizing configuration of off-grid diesel generator system with solar-storage replacement according to claim 6, characterized in that: The implementation of step 3.3 includes: performing an accurate search based on the interval obtained in step 3.2.3, and setting the energy storage capacity at the kth iteration to , the energy storage capacity setting value at the first iteration As the starting point of the search range obtained in step 3.2.3, the energy storage capacity is set to the minimum value The end point of the search range obtained in step 3.2.3; the specific steps are as follows: Step 3.3.1, due to the energy storage capacity configuration value This decision variable has been assigned Therefore, the solar-storage-diesel joint optimization model built in step 2 is also simplified to a solar-storage-diesel joint optimization fast solution model, and the objective function of this model is: （1.35） The constraints of the model are: （1.36） （1.37） （1.38） （1.39） （1.40） （1.41） （1.42） （1.43） （1.44）； Step 3.3.

2. Use the Big M method to handle the nonlinear constraints in the rapid solution model for the combined optimization of solar-storage-diesel energy storage capacity, namely, the constraint equations (1.40) and (1.43) between the real-time power and capacity of the energy storage. Solve the model to obtain the solution values for the photovoltaic capacity, the diesel generator, and the comprehensive cost. The specific steps are as follows: Step 3.3.2.

1. Define 8760 0-1 variables , t∈[1,8760]; Step 3.3.2.

2. Define a large number ; Step 3.3.2.

3. Rewrite the constraints (3.3.6)-(3.3.9) between the real-time power and real-time capacity of the energy storage in the energy storage capacity fast solution model into the following constraints: （1.45） （1.46） (1.47) （1.48） （1.49） （1.50） （1.51） （1.52） （1.53） （1.54） Step 3.3.2.

4. Solve the energy storage capacity fast solution model. The objective function is Equation (1.35), and the constraints are Equations (1.36)-(1.39), (1.44)-(1.54). The photovoltaic capacity solution is obtained. 、Calculation of diesel generator output power for 8760 hours , comprehensive cost solution value ; Step 3.3.2.

5. Diesel generator solution The maximum value of the diesel generator's output power for 8760 hours is: （1.55）； Step 3.3.

3. If and When , the energy storage configuration value in the optimal solution of the solar-storage-diesel joint optimization model is for , PV configuration value for , diesel generator capacity configuration value for If it is not satisfied, it means that the optimal solution has not been found. , the search end point has not been reached. , repeat step 3.3.2; if The search endpoint has been reached, and the energy storage configuration value in the optimal solution of the photovoltaic, storage and diesel joint optimization model is , PV configuration value for , diesel generator capacity configuration value for .

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory, characterized in that: The processor executes the computer program to implement the steps of the method for optimizing the configuration of the photovoltaic storage replacement transformation of an off-grid diesel generator system as described in any one of claims 1 to 7.

9. A computer-readable storage medium having a computer program / instruction stored thereon, characterized in that: When the computer program / instructions are executed by a processor, the steps of the method for optimizing the configuration of the photovoltaic storage replacement transformation of an off-grid diesel generator system as described in any one of claims 1 to 7 are implemented.

10. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instruction is executed by a processor, the steps of the method for optimizing the configuration of the photovoltaic storage replacement transformation of the diesel-generator off-grid system described in any one of claims 1 to 7 are implemented.

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