Photovoltaic power station design method based on digital twin model

Abstract

The present invention relates to a photovoltaic power station design method based on a digital twin model, which belongs to the field of photovoltaic system simulation technology, and includes the following operating steps: Step 1: The investment return estimation module performs basic investment budget and investment return estimation on the entire project. Step 2: The grid-connected calculation tool module is used for the design calculation of the photovoltaic power station. Step 3: A digital platform carrier is created through a digital twin model to be provided to the entire photovoltaic power station scheme design stage, design scheme optimization stage, and operation and maintenance stage. Step 4: The array photovoltaic components and inverters are connected in series and parallel according to the design scheme through the system series-parallel module. Step 5: Export as a data file and directly import it into the simulation software. Step 6: The deficiencies of the simulation results are adjusted and corrected in the digital model in a timely manner until the optimal design scheme is reached. A digital twin system for a grid-connected photovoltaic power station is realized that creates a digital twin model and realizes the actual application of the digital twin model.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic system simulation, and in particular to a photovoltaic power station design method based on a digital twin model. Background Art

[0002] The traditional design method of photovoltaic power stations mainly relies on designers to select appropriate component types and specifications based on survey data and historical light data, according to factors such as system power, structural layout, and light conditions; after calculation, use appropriate inverters and combiner boxes to formulate overall power distribution plans for photovoltaic arrays; conduct an overall benefit analysis of the plan, and manually input the calculated design data and collected environmental data into simulation software to optimize the design plan; however, the traditional design method has the following major defects:

[0003] (1) Large amount of data preparation work: In the design of photovoltaic power stations, a large amount of calculations need to be performed, and the various components need to cooperate as a whole to ensure the security of data such as power, current, and voltage;

[0004] (2) Fragmentation of computing modules: The factors involved in photovoltaic calculations are very complex. For example, the safety of equipment current and voltage, the rationality of power and layout, and the economic feasibility of the overall solution all require detailed calculations. However, different factors need to be considered at different stages of the project, resulting in the separation of computing modules and a lack of mutual linkage.

[0005] (3) Difficulty in modification and optimization: The segmentation of computing modules and the backward data recording and transmission methods make the use and transmission of designs before and after very inconvenient. It is impossible to modify one place and update everywhere, making it difficult to carry out the modification and optimization of the entire photovoltaic design.

[0006] (4) Difficulty in learning and using: Only personnel who have undergone learning and training can participate in the use, which leads to difficulty in getting started and high costs;

[0007] (5) Unintuitive expression: Traditional design solutions use charts, numbers, and text, which are not intuitive and three-dimensional. They are difficult for people in the industry to view and difficult to show to non-professionals. Summary of the invention

[0008] The present invention mainly solves the deficiencies in the prior art and provides a photovoltaic power station design method based on a digital twin model, a digital design method that uses digital twin model parameters to carry photovoltaic design information, uses programming codes to automatically calculate photovoltaic data, and uses software APIs for data transmission; and realizes the creation of a digital twin model and the actual application of a digital twin system for a grid-connected photovoltaic power station.

[0009] The above technical problems of the present invention are mainly solved by the following technical solutions:

[0010] A photovoltaic power station design method based on a digital twin model includes the following steps:

[0011] Step 1: During the PV project establishment phase, the ROI estimation module provides basic investment estimates and ROI estimates for the entire project; helps investors and decision makers better understand the economic and social benefits of the project, and provides data support and scientific basis for project decision-making and implementation.

[0012] Step 2: The grid-connected calculation tool module provides designers with a simple, convenient and fast calculation toolbox, which is professionally used for the design and calculation of photovoltaic power stations; the grid-connected calculation tool module is used to perform simple preliminary calculations for a project and provide the design scope of the preliminary design plan as the basis for the preliminary creation of the digital twin model.

[0013] It solves the pain points of long time, high cost and high error rate in the traditional design process; under the premise of determining the models of photovoltaic components and grid-connected inverters, this module can realize the installed capacity, series calculation, series-parallel verification and DC and AC cable calculation functions.

[0014] Step 3: Use the digital twin model to create a digital platform carrier for use in the entire photovoltaic power station design phase, design optimization phase, and operation and maintenance phase; the implementation steps of the digital twin model creation module include: creating simulation projects, exporting shadow scenes, component arrays, and inverters.

[0015] Step 4: Use the system series-parallel module to connect the array photovoltaic components and inverters created by the digital twin model creation module in series and parallel in a designed manner to form a complete photovoltaic power generation component module system.

[0016] Step 5: Use the simulated power generation module to export the key data in the digital twin model created by the photovoltaic design scheme as a data file and directly import it into the simulation software.

[0017] Step 6: Make timely adjustments and corrections to the deficiencies in the simulation results in the digital model until the optimal design solution is reached.

[0018] As a preferred option, the investment estimate is to obtain the local annual total radiation energy data based on the project's geographical location and local meteorological data, select the appropriate photovoltaic module type according to the different project characteristics, determine the module conversion efficiency, and calculate the photovoltaic array area and expected power generation; the return on investment is to calculate the power generation cost, power station profit and investment return rate, and perform relevant investment return related calculations by inputting the corresponding cost information.

[0019] Preferably, the digital twin model has the following characteristics:

[0020] S1: Model the geometric shapes of all components used in the entire photovoltaic power station design and the environmental model of the project.

[0021] S2: The electrical properties of the electrical model involved in the digital twin model.

[0022] S3: The photovoltaic power station system composed of the digital twin model has an inherent behavioral logic that complies with photovoltaic design specifications.

[0023] This is achieved through the family instance parameter type in the Revit electrical family, PVDT's data capture of the instance family in the Revit project, and PVDT's internal calculation programming language.

[0024] As a preferred embodiment, the internal calculation content and calculation formula of PVDT photovoltaic are as follows:

[0025] Component calculation:

[0026] Component minimum temperature t'= (thmin+ (NOCT-20) × 0.2 ÷ 0.8);

[0027] Component maximum temperature t = (thmax + (NOCT-20) × 0.2 ÷ 0.8);

[0028] The maximum number of components in series Nmax = Vdcmax / Voc / (1+(t'-25)×Kv);

[0029] Minimum number of components in series Nmin = Vmpptmin / Vpm / (1+(t-25)×Kv');

[0030] The minimum voltage of each string Vsmin = N × Vpm × (1 + (t-25) × Kv');

[0031] The maximum voltage of each string Vsmax = N × Voc × (1 + (t'-25) × Kv);

[0032] thmin: historical extremely low temperature; thmax: historical extremely high temperature; Voc: open circuit voltage; Vpm: peak power voltage; (Kv)%: open circuit voltage coefficient; (Kv')%: peak voltage coefficient (maximum power temperature coefficient); NOCT: battery operating temperature; Vdcmax: maximum DC input voltage; Vmpptmin: minimum full-load MPPT voltage; Vmpptmax: maximum full-load MPPT voltage.

[0033] Inverter verification:

[0034] Inverter power verification Wp: Wmp×M×N≤1:1.3;

[0035] Inverter voltage verification Vmpptmin≤N×Voc≤Vmpptmax;

[0036] Inverter current verification: Isc×N≤I;

[0037] Wp: inverter power; Wmp: photovoltaic module power; M: number of series modules; N: number of parallel strings; Isc: battery module short-circuit current.

[0038] Cable calculation:

[0039] DC cable: allowable voltage reduction ΔU=Vmp×N×1%;

[0040] Cable length L = ΔU × S / (2 × Imp × ρ);

[0041] AC cable: voltage drop rate Rv=ρ×L×I / (S×U);

[0042] Maximum power current of the cable I=P / (1.732×U×cosθ);

[0043] Voltage drop ΔU=Rv×U;

[0044] Cable length L = ΔU × 1.732 × U × cosθ × S / (P × ρ);

[0045] U: string inverter voltage; P: maximum inverter output power; I: maximum inverter output current; ρ: cable copper core resistivity; Vmp: maximum power operating voltage of the component; Imp: maximum power operating current of the component; cosθ: component power factor; S: cable cross-sectional area.

[0046] As a preference, a photovoltaic module, inverter, and discharge junction box family model is created by restoring the market model specifications in a one-to-one ratio; the solar cell array bracket layout adopted in the design plan; the photovoltaic modules are connected in series and parallel according to the series and parallel connection method of the designed solar panel components and inverters; the photovoltaic power station design layout scope, work plane and building appearance; the external building environment volume model of the entire photovoltaic power station.

[0047] Preferably, the power ratio between the inverter and the connected PV modules is 1:1; in the case of over-capacity, the power capacity ratio between the inverter power and the connected PV modules does not exceed 1.3, and automatic calculation is performed to ensure that the battery array voltage is greater than the minimum full-load MPPT voltage and less than the maximum full-load MPPT voltage, and to ensure that the maximum output current of the battery array in the design is not greater than the maximum input current of the inverter.

[0048] Preferably, the implementation steps of the digital twin model creation module include:

[0049] S1: The project location information should be set before modeling; in the Revit management interface, click the "Location" function in the "Project Location" function.

[0050] S2: Click the "Create Simulation Project" button in the PVDT modeling module, select the project save path, fill in the "Project Name", "Simulation Description" and serial number. Photovoltaic simulation often performs multiple single-variable simulation calculations for a variety of different variable conditions. "Simulation Description" refers to the current variable characteristics, and the extension of each calculation project is named with vc+serial number, which is determined here; click OK to generate the data file, and the generated data file is directly imported into the simulation software to provide the project's geographical and meteorological environment model information.

[0051] S3: Select the corresponding 3D view in Revit, select the main volume 3D view, and click the "Export Shadow Scene" function in the PVDT modeling module; select the file save location, select the PV module volume 3D view, and click the "Export Shadow Scene" function; select the file save location; output the main volume and PV module volume FBX format files to provide data information for the shadow analysis of the PV project.

[0052] S4: Click the "Component Array" function in the PVDT modeling module. According to the design file, first select the manufacturer, then select the power and specific PV component model; set the number of rows and columns of PV components, and set the component spacing. After the settings are completed, click the layout button, select the work plane with the mouse cross cursor and then pick up the insertion point of the PV component to realize the layout of the PV component, give the direction point to determine the layout direction of the component array, and complete the component array layout.

[0053] S5: Click the "Inverter" function in the PVDT modeling module, select the "MPPT number" of the inverter according to the design file, then select the relevant "manufacturer" and "power", and finally determine the specific inverter model; click the "Layout" button to create the inverter model, first select the working plane, and then capture the insertion point.

[0054] Preferably, click the "Connect" button in the PVDT system series-parallel module, select the component array, click "Finish" to end the selection, then select the inverter to be connected, specify the connection multi-channel MPPT serial number in the dialog box, and confirm the access group string number, and finally click the "Connect" button; the PV components are automatically connected, and the inverter number and inverter group string number to which the PV panel belongs are also updated in the instance properties of the corresponding PV component model.

[0055] Preferably, check through the "Status" button in the PVDT system series-parallel module; click the "Status" button, select the inverter, and a dialog box pops up to display the number of series components connected to each string number of each MPPT of the inverter; check the position of the specific string in the model, select the specific string number in the MPPT sequence, and then click the "Corresponding Component" button; modify the connection relationship between the inverter and the component, first release the connection, select the specific string number in the MPPT sequence, and then click the "Release Connection" button; click the "Check Number of Strings" button to check whether the same MPPT is connected to strings with different numbers of series connections. When strings with different numbers of components in series are connected to the same MPPT, the MPPT circuit will take into account the component strings with fewer series connections and lower voltages, which can easily lead to tracking confusion and voltage mismatch problems.

[0056] Preferably, before data is transmitted, the entire photovoltaic system is automatically checked through calculations in accordance with photovoltaic design specifications to avoid errors, making the system check faster, more efficient and more accurate; it includes three inspection functions: "components are not connected to inverters", "inverter numbers of components" and "number of components in each MPPT string". Click the "components are not connected to inverters" button in the "system check" module in the PVDT system simulated power generation to display free photovoltaic components that are not connected to inverters in the interface. Click the "component inverter number" button in the "system check" module in the PVDT system simulated power generation to check whether the inverter number in the component attribute parameters is incorrect due to the modification of the model and the failure to update the component in time, resulting in incorrect generated data. Click the "number of components in each MPPT string" button in the "system check" module in the PVDT system simulated power generation to check whether the number of components in the inverter MPPT string is consistent with the inverter number data of all components in the model.

[0057] After completing the system check, generate the data required by the simulation software and transfer the data to the holographic simulation software for holographic simulation to facilitate solution optimization. Click the "Prepare Simulation Data" button in the "Simulated Power Generation" module in PVDT, select the project save path, fill in the "Project Name", "Simulation Description" and serial number, and click OK to generate the data file.

[0058] There are two holographic simulation systems for docking. The first simulation path is PVsyst software. PVsyst software is a holographic simulation software widely used in the design and performance prediction of photovoltaic power stations, rooftop photovoltaic systems and distributed photovoltaic systems. It has the advantages of high-precision simulation capabilities, high global recognition, comprehensive functions, and accurate shadow analysis, but it also has defects such as high entry barriers and too many operation input parameters. The second holographic simulation path is Pvlib, which is technically supported by the technical team of Princeton University. It is an open source Python library dedicated to simulating and analyzing the performance of photovoltaic (PV) energy systems, providing a series of tools and functions for calculating solar irradiance, predicting the power generation of photovoltaic systems, and evaluating the performance of photovoltaic modules.

[0059] The present invention can achieve the following effects:

[0060] The present invention provides a photovoltaic power station design method based on a digital twin model. Compared with the prior art, the digital twin model parameters are used to carry photovoltaic design information, programming codes are used to automatically calculate photovoltaic data, and software APIs are used to transmit data. A digital twin system for a grid-connected photovoltaic power station is created and implemented to realize the actual application of the digital twin model.

[0061] Through the Revit API (application programming interface) development tool provided by Revit (modeling software), the complex calculations required for the design of photovoltaic power stations are implemented through internal programming; access and operate the data, models, and functions within Revit to automatically create a digital twin model of the photovoltaic power station; after the digital twin model is created according to the design plan, the program collects model data and performs calculations to check whether the established photovoltaic component layout meets the specifications; after the inspection, the digital twin model that meets the standards is converted into a file that can be directly imported into the simulation software and a calculation book with detailed calculation formulas. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 It is a workflow diagram of the PVDT system design optimization of the present invention. DETAILED DESCRIPTION

[0063] The technical solution of the invention is further specifically described below through embodiments and in conjunction with the accompanying drawings.

[0064] Example: Figure 1 As shown, a photovoltaic power station design method based on a digital twin model includes the following steps:

[0065] Step 1: In the PV project establishment stage, the ROI estimation module makes basic investment estimates and ROI estimates for the entire project. The investment estimate is based on the project's geographical location and local meteorological data to obtain local annual total radiation data. According to the different project characteristics, the appropriate PV module type is selected, the module conversion efficiency is determined, and the PV array area and expected power generation are calculated. The ROI is to calculate the power generation cost, power station profit and investment return rate. By entering the corresponding cost information, relevant ROI related calculations are performed.

[0066] Step 2: The grid-connected calculation tool module is used for the design calculation of the photovoltaic power station. The grid-connected calculation tool module is used to perform simple preliminary calculations for a project and provide the design scope of the preliminary design plan as the basis for the preliminary creation of the digital twin model.

[0067] Step 3: Use the digital twin model to create a digital platform carrier for use in the entire photovoltaic power station design phase, design optimization phase, and operation and maintenance phase.

[0068] The digital twin model has the following characteristics:

[0069] S1: Model the geometric shapes of all components used in the entire photovoltaic power station design and the environmental model of the project. The photovoltaic components, inverters, and discharge combiner box family models are created based on the market model specifications and appearance. The solar cell array bracket layout adopted in the design plan; the photovoltaic components are connected in series and parallel according to the series and parallel connection method of the designed solar panel components and inverters; the design layout scope, working plane and building appearance of the photovoltaic power station; the external building environment volume model of the entire photovoltaic power station.

[0070] S2: The electrical properties of the electrical model involved in the digital twin model.

[0071] The number of cells, maximum power, open circuit voltage, open circuit voltage coefficient, peak power voltage, peak voltage coefficient, cell operating temperature, short circuit current, maximum power operating current and cable size of monocrystalline silicon solar panels.

[0072] S3: The photovoltaic power station system composed of the digital twin model has an inherent behavioral logic that complies with photovoltaic design specifications. The power ratio of the inverter to the connected photovoltaic module is 1:1; in the case of over-capacity, the power capacity ratio of the inverter power to the connected photovoltaic module power does not exceed 1.3, and the automatic calculation ensures that the battery array voltage is greater than the minimum full-load MPPT voltage and less than the maximum full-load MPPT voltage, ensuring that the maximum output current of the battery array in the design is not greater than the maximum input current of the inverter.

[0073] This is achieved through the family instance parameter type in the Revit electrical family, PVDT's data capture of the instance family in the Revit project, and PVDT's internal calculation programming language.

[0074] The internal calculation content and calculation formula of PVDT photovoltaic are as follows:

[0075] Component calculation:

[0076] Component minimum temperature t'= (thmin+ (NOCT-20) × 0.2 ÷ 0.8);

[0077] Component maximum temperature t = (thmax + (NOCT-20) × 0.2 ÷ 0.8);

[0078] The maximum number of components in series Nmax = Vdcmax / Voc / (1+(t'-25)×Kv);

[0079] Minimum number of components in series Nmin = Vmpptmin / Vpm / (1+(t-25)×Kv');

[0080] The minimum voltage of each string Vsmin = N × Vpm × (1 + (t-25) × Kv');

[0081] The maximum voltage of each string Vsmax = N × Voc × (1 + (t'-25) × Kv);

[0082] thmin: historical extremely low temperature; thmax: historical extremely high temperature; Voc: open circuit voltage; Vpm: peak power voltage; (Kv)%: open circuit voltage coefficient; (Kv')%: peak voltage coefficient (maximum power temperature coefficient); NOCT: battery operating temperature; Vdcmax: maximum DC input voltage; Vmpptmin: minimum full-load MPPT voltage; Vmpptmax: maximum full-load MPPT voltage;

[0083] Inverter verification:

[0084] Inverter power verification Wp: Wmp×M×N≤1:1.3;

[0085] Inverter voltage verification Vmpptmin≤N×Voc≤Vmpptmax;

[0086] Inverter current verification: Isc×N≤I;

[0087] Wp: inverter power; Wmp: photovoltaic module power; M: number of series modules; N: number of parallel strings; Isc: short-circuit current of battery module;

[0088] Cable calculation:

[0089] DC cable: allowable voltage reduction ΔU=Vmp×N×1%;

[0090] Cable length L = ΔU × S / (2 × Imp × ρ);

[0091] AC cable: voltage drop rate Rv=ρ×L×I / (S×U);

[0092] Maximum power current of the cable I=P / (1.732×U×cosθ);

[0093] Voltage drop ΔU=Rv×U;

[0094] Cable length L = ΔU × 1.732 × U × cosθ × S / (P × ρ);

[0095] U: string inverter voltage; P: maximum inverter output power; I: maximum inverter output current; ρ: cable copper core resistivity; Vmp: maximum power operating voltage of the component; Imp: maximum power operating current of the component; cosθ: component power factor; S: cable cross-sectional area.

[0096] The implementation steps of the digital twin model creation module include: creating simulation projects, exporting shadow scenes, component arrays, and inverters. The specific implementation steps are as follows:

[0097] S1: Before modeling, you should set the project location information. In the Revit management interface, click the "Location" function in the "Project Location" function.

[0098] S2: Click the "Create Simulation Project" button in the PVDT modeling module, select the project save path, fill in the "Project Name", "Simulation Description" and serial number. Photovoltaic simulation often performs multiple single-variable simulation calculations for a variety of different variable conditions. "Simulation Description" refers to the current variable characteristics, and the extension of each calculation project is named with vc+serial number, which is determined here; click OK to generate the data file, and the generated data file is directly imported into the simulation software to provide the project's geographical and meteorological environment model information.

[0099] S3: Select the corresponding 3D view in Revit, select the main volume 3D view, and click the "Export Shadow Scene" function in the PVDT modeling module; select the file save location, select the PV module volume 3D view, and click the "Export Shadow Scene" function; select the file save location; output the main volume and PV module volume FBX format files to provide data information for the shadow analysis of the PV project.

[0100] S4: Click the "Component Array" function in the PVDT modeling module. According to the design file, first select the manufacturer, then select the power and specific PV component model; set the number of rows and columns of PV components, and set the component spacing. After the settings are completed, click the layout button, select the work plane with the mouse cross cursor and then pick up the insertion point of the PV component to realize the layout of the PV component, give the direction point to determine the layout direction of the component array, and complete the component array layout.

[0101] S5: Click the "Inverter" function in the PVDT modeling module, select the "MPPT number" of the inverter according to the design file, then select the relevant "manufacturer" and "power", and finally determine the specific inverter model; click the "Layout" button to create the inverter model, first select the working plane, and then capture the insertion point.

[0102] Step 4: Use the system series-parallel module to connect the array photovoltaic components and inverters created by the digital twin model creation module in series and parallel in a designed manner to form a complete photovoltaic power generation component module system.

[0103] Click the "Connect" button in the PVDT system series-parallel module, select the component array, click "Finish" to end the selection, then select the inverter to be connected, specify the serial number of the connected multi-channel MPPT in the dialog box, and confirm the access group string number, and finally click the "Connect" button; the PV components are automatically connected, and the instance properties of the corresponding PV component model are also updated to record the inverter number and inverter group string number to which the PV panel belongs.

[0104] Check through the "Status" button in the PVDT system series-parallel module; click the "Status" button, select the inverter, and a dialog box will pop up to display the number of series components connected to each string number of each MPPT of the inverter; check the position of the specific string in the model, select the specific string number in the MPPT sequence, and then click the "Corresponding Component" button; modify the connection relationship between the inverter and the component, first release the connection, select the specific string number in the MPPT sequence, and then click the "Release Connection" button; click the "Check String Number" button to check whether the same MPPT is connected to strings with different series numbers. When strings with different component series numbers are connected to the same MPPT, the MPPT circuit will take into account the component strings with fewer series connections and lower voltages, which can easily lead to tracking confusion and voltage mismatch problems.

[0105] Step 5: Use the simulated power generation module to export the key data in the digital twin model created by the photovoltaic design scheme as a data file and directly import it into the simulation software.

[0106] Before data transmission, the entire photovoltaic system is automatically checked through calculations based on photovoltaic design specifications to avoid errors. The system check is faster, more efficient and more accurate. It includes three check functions: "Components are not connected to inverters", "Inverter number of components" and "Number of components in each MPPT string". Click the "Components are not connected to inverters" button in the "System Check" module of the PVDT system simulation power generation to display the free photovoltaic components that are not connected to the inverter in the interface. Click the "Inverter number of components" button in the "System Check" module of the PVDT system simulation power generation to check whether the inverter number in the component attribute parameters is incorrect due to the modification of the model and the failure to update the components in time, resulting in incorrect generated data. Click the "Number of components in each MPPT string" button in the "System Check" module of the PVDT system simulation power generation to check whether the number of components in the inverter MPPT string is consistent with the inverter number data of all components in the model.

[0107] After completing the system check, generate the data required by the simulation software and transfer the data to the holographic simulation software for holographic simulation to facilitate solution optimization. Click the "Prepare Simulation Data" button in the "Simulated Power Generation" module in PVDT, select the project save path, fill in the "Project Name", "Simulation Description" and serial number, and click OK to generate the data file.

[0108] Step 6: Make timely adjustments and corrections to the deficiencies in the simulation results in the digital model until the optimal design solution is reached. By analyzing the simulation results, make positive adjustments to the unfavorable factors of photovoltaic power generation, and continue to simulate the adjusted design solution until the simulation results meet the design requirements, ensuring that the design solution meets or even exceeds the expected design standards, and achieving the completion of the optimal design solution. In the photovoltaic power generation design process of the digital twin model, solution optimization is extremely convenient. Only the design parameters that need to be modified are adjusted separately. The entire design solution and its related other parameters, calculation results, and the output of the overall design solution are automatically calculated by the internal program of the digital twin model. Compared with the traditional design process, the time required for the optimization stage of the solution design can be shortened from one month to two days, which greatly shortens the photovoltaic engineering design cycle, improves photovoltaic design efficiency, reduces time cost and labor cost, and realizes the automation leap of photovoltaic design solution optimization.

[0109] In summary, the photovoltaic power station design method based on the digital twin model is applied to the whole stage of photovoltaic project establishment, design, optimization and implementation. The digital design method uses digital twin model parameters to carry photovoltaic design information, uses programming code to automatically calculate photovoltaic data, and uses software API for data transmission. A digital twin system for grid-connected photovoltaic power stations is created and implemented to realize the actual application of digital twin models.

[0110] The above description is only a specific embodiment of the present invention, but the structural features of the present invention are not limited thereto. Any changes or modifications made by any technician in the field of the present invention are included in the patent scope of the present invention.

Claims

1. A photovoltaic power station design method based on digital twin model, characterized by The steps are as follows: Step 1: During the PV project approval phase, the ROI estimation module provides a basic investment estimate and ROI estimate for the entire project. Step 2: The grid-connected calculation tool module is used for design calculation of photovoltaic power stations; Step 3: Use the digital twin model to create a digital platform carrier for use in the entire photovoltaic power station design phase, design optimization phase, and operation and maintenance phase; The implementation steps of the digital twin model creation module include: creating a simulation project, exporting shadow scenarios, component arrays, and inverters; The digital twin model has the following characteristics: Feature 1: Modeling the geometric shapes of all components used in the entire photovoltaic power station design and the environmental model of the project; Feature 2: The digital twin model involves the electrical properties of the electrical appliance model; Feature 3: The photovoltaic power station system constructed by the digital twin model has an inherent behavioral logic that complies with photovoltaic design specifications; Through the family instance parameter type in the Revit electrical family, PVDT is used to capture the data of the instance family in the Revit project, and then the internal operation programming language of PVDT is used to implement it; The internal calculation content and calculation formula of PVDT photovoltaic are as follows: Component calculation: Component minimum temperature t' = (thmin + (NOCT-20) × 0.2 ÷ 0.8); Component maximum temperature t = (thmax + (NOCT-20) × 0.2 ÷ 0.8); Maximum number of modules in series Nmax = Vdcmax / Voc / (1+(t'-25)×Kv); Minimum number of modules in series Nmin = Vmpptmin / Vpm / (1+(t-25)×Kv'); The minimum voltage of each string Vsmin = N × Vpm × (1 + (t-25) × Kv'); The maximum voltage of each string Vsmax = N × Voc × (1 + (t'-25) × Kv); thmin: historical extreme low temperature; thmax: historical extreme high temperature; Voc: open circuit voltage; Vpm: peak power voltage; Kv: open circuit voltage coefficient; Kv': peak voltage coefficient (maximum power temperature coefficient); NOCT: battery operating temperature; Vdcmax: maximum DC input voltage; Vmpptmin: minimum full-load MPPT voltage; Vmpptmax: maximum full-load MPPT voltage; Inverter verification: Inverter power verification Wp: Wmp×M×N≤1∶1.3; Inverter voltage verification Vmpptmin≤N×Voc≤Vmpptmax; Inverter current verification: Isc×N≤I; Wp: inverter power; Wmp: PV module power; M: number of series modules; N: number of parallel strings; Isc: short-circuit current of the battery module; Cable calculation: DC cable: allowable voltage drop ΔU = Vmp × N × 1%; Cable length L = ΔU × S / (2 × Imp × ρ); AC cable: voltage drop rate Rv = ρ × L × I / (S × U); Maximum power current of the cable I = P / (1.732 × U × cos θ); Voltage drop ΔU = Rv × U; Cable length L = ΔU × 1.732 × U × cos θ × S / (P × ρ); U: string inverter voltage; P: inverter maximum output power; I: inverter maximum output current; ρ: cable copper core resistivity; Vmp: module maximum power operating voltage; Imp: module maximum power operating current; cos θ: module power factor; S: cable cross-sectional area; Step 4: Use the system series-parallel module to connect the array photovoltaic components and inverters created by the digital twin model creation module in a designed series-parallel manner to form a complete photovoltaic power generation component module system; Step 5: Use the simulated power generation module to export key data from the digital twin model created by the photovoltaic design scheme as a data file and directly import it into the simulation software; Step 6: Make timely adjustments and corrections to the deficiencies in the simulation results in the digital model.

2. The photovoltaic power station design method based on the digital twin model according to claim 1 is characterized by: The investment estimate is based on the project's geographical location and local meteorological data to obtain local annual total radiation energy data, select the appropriate photovoltaic module type, determine the module conversion efficiency, and calculate the photovoltaic array area and expected power generation; the return on investment is to calculate the power generation cost, power station profit and investment return rate. By entering the corresponding cost information, relevant investment return related calculations are performed.

3. The photovoltaic power station design method based on the digital twin model according to claim 1 is characterized by: The power ratio between the inverter and the connected PV panels is 1:

1. In the case of over-capacity, the power capacity ratio between the inverter power and the connected PV panels does not exceed 1.

3. Automatic calculation ensures that the battery array voltage is greater than the minimum full-load MPPT voltage, and automatically calculates that the battery array voltage is less than the maximum full-load MPPT voltage, ensuring that the maximum output current of the battery array in the design is not greater than the maximum input current of the inverter.

4. The photovoltaic power station design method based on the digital twin model according to claim 1 is characterized in that The implementation steps of the digital twin model creation module include: S1: Before modeling, you should set the project location information first; in the Revit management interface, click the "Location" function in the "Project Location" function; S2: Click the "Create Simulation Project" button in the PVDT modeling module, select the project save path, and fill in the "Project Name," "Simulation Description," and serial number. PV simulations often perform multiple single-variable simulations for a variety of different variable conditions. "Simulation Description" refers to the current variable characteristics, and each calculation project is named with the extension vc + serial number, which is determined here. Click OK to generate the data file, which can be directly imported into the simulation software to provide the project's geographical and meteorological environment model information. S3: Select the corresponding 3D view in Revit, select the main volume 3D view, and click the "Export Shadow Scene" function in the PVDT modeling module; select the file save location, select the PV panel volume 3D view, and click the "Export Shadow Scene" function; select the file save location; export the main volume and PV panel volume PBX format files to provide data information for shadow analysis of the PV project; S4: Click the "Module Array" function in the PVDT modeling module; according to the design file, first select the manufacturer, then the power and specific PV module model; set the number of rows and columns of PV modules, and set the module spacing. After setting, click the "Layout" button. Use the mouse crosshairs to select the work plane and then pick the insertion point of the PV module to arrange the PV modules. Specify the direction point to determine the layout direction of the module array, and then complete the module array layout; S5: Click the "Inverter" function in the PVDT modeling module. Based on the design file, select the inverter's "MPPT number," then the relevant "Manufacturer" and "Power," and finally determine the specific inverter model. Click the "Layout" button to create the inverter model. First, select the work plane, then capture the insertion point.

5. The photovoltaic power station design method based on the digital twin model according to claim 1 is characterized in that: Click the "Connect" button in the PVDT System Series-Parallel Connection module, select the module array, and click "Finish" to complete the selection. Then select the inverter to be connected. In the dialog box, specify the serial number of the connected multiple MPPTs and confirm the access group string number. Finally, click the "Connect" button. The PV modules are automatically connected, and the instance properties of the corresponding PV module model are also updated to record the inverter number and inverter string number to which the PV panel belongs.

6. The photovoltaic power station design method based on the digital twin model according to claim 5 is characterized by: Check the PVDT system series-parallel connection by clicking the "Status" button. Click the "Status" button and select the inverter. A dialog box will pop up, displaying the number of series modules connected to each string number on each MPPT of the inverter. Check the position of a specific string in the model, select the specific string number in the MPPT sequence, and click the "Corresponding Component" button. Modify the connection between the inverter and the module by first disconnecting it, selecting the specific string number in the MPPT sequence, and clicking the "Disconnect" button. Click the "Check String Number" button to check whether the same MPPT has strings with different series numbers connected. When strings with different series numbers are connected to the same MPPT, the MPPT circuit will consider strings with fewer series connections and lower voltages, which can easily lead to tracking confusion and voltage mismatch.

7. The photovoltaic power station design method based on the digital twin model according to claim 5 is characterized by: Before data transmission, the entire PV system is automatically checked based on calculations in accordance with PV design specifications to avoid errors. This includes three check functions: "Module not connected to inverter," "Module inverter number," and "Number of modules in each MPPT string." Clicking the "Module not connected to inverter" button in the "System Check" module of the PVDT system simulated power generation will display the free PV modules not connected to the inverter on the interface. Clicking the "Module inverter number" button in the "System Check" module of the PVDT system simulated power generation will check for incorrect inverter numbers in the module attribute parameters due to model modifications and untimely component updates, resulting in incorrect generated data. Clicking the "Number of modules in each MPPT string" button in the "System Check" module of the PVDT system simulated power generation will check whether the number of modules in the inverter MPPT strings is consistent with the inverter number data of all modules in the model. After completing the system inspection, the data required by the simulation software is generated and passed to the holographic simulation software for holographic simulation to facilitate solution optimization.

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