Calculation method and related device for back irradiation distribution of bifacial photovoltaic modules

Abstract

The present application discloses a method for calculating the back irradiance distribution of a bifacial photovoltaic module and a related device, which relate to the field of photovoltaic power generation. In the calculation process, the shadow shielding of the back of the bifacial photovoltaic module by the supporting structure is fully considered, and the problem of inaccurate calculation of the back irradiance distribution of the bifacial photovoltaic module under the shielding of the supporting structure is solved. At the same time, by determining the position of the target photovoltaic array in the two-dimensional Cartesian coordinate system and the boundary of the supporting structure in the two-dimensional Cartesian coordinate system, the sky scattered irradiance, ground reflected irradiance and direct irradiance received by the part of the back of each cell in the bifacial photovoltaic module that is not shielded by the supporting structure are calculated, so as to realize the calculation of the back irradiance distribution of the bifacial photovoltaic module in the two-dimensional scene, reduce the calculation amount and improve the calculation speed while maintaining high calculation accuracy.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic power generation technology, and in particular to a method for calculating the back side irradiation distribution of a double-sided photovoltaic module and a related device. Background Art

[0002] Bifacial photovoltaic modules are photovoltaic modules that can receive radiation on both the front and back sides. Compared with traditional single-sided photovoltaic modules, bifacial photovoltaic modules can generate more electricity and maximize the use of radiation resources.

[0003] In the actual installation process, the back of the bifacial photovoltaic module is usually close to the main axis or main beam, resulting in the main axis or main beam casting a shadow on the back of the module. However, when calculating the irradiation distribution on the back of the bifacial photovoltaic module, the shading caused by the supporting structure (such as the main axis and main beam) is often ignored, resulting in low accuracy in the calculation of the irradiation distribution on the back of the bifacial photovoltaic module, and it is impossible to reasonably and accurately evaluate the performance of the bifacial photovoltaic system. Summary of the invention

[0004] In view of the above problems, this application provides a method and related device for calculating the back irradiance distribution of a bifacial photovoltaic module to achieve the purpose of quickly and accurately calculating the back irradiance distribution of a bifacial photovoltaic module. The specific scheme is as follows:

[0005] The first aspect of the present application provides a method for calculating the back irradiance distribution of a bifacial photovoltaic module, comprising:

[0006] According to the arrangement position of the target photovoltaic array, the preset ground range in front and behind the target photovoltaic array is divided into n ground areas along the front-to-back direction, where n is a positive integer;

[0007] Calculating the irradiance received by each ground area according to the arrangement position, installation parameters and current sun position vector of the target photovoltaic array;

[0008] Determine the position of the target photovoltaic array in a two-dimensional Cartesian coordinate system, and determine the boundary of the support structure in the target photovoltaic array in the two-dimensional Cartesian coordinate system;

[0009] Calculate the sky scattered radiation received by the portion of the back side of each cell in the bifacial photovoltaic assembly in the target photovoltaic array that is not shielded by the support structure according to the position of the target photovoltaic array in the two-dimensional Cartesian coordinate system and the boundary of the support structure in the two-dimensional Cartesian coordinate system;

[0010] Calculate the ground reflected irradiance received by the portion of the back side of each cell in the bifacial photovoltaic module that is not blocked by the support structure according to the position of the target photovoltaic array in the two-dimensional Cartesian coordinate system, the boundary of the support structure in the two-dimensional Cartesian coordinate system, and the irradiance received by each segment of the ground area;

[0011] Calculate the direct radiation received by the back side of each cell in the bifacial photovoltaic module according to the arrangement position, installation parameters and current sun position vector of the target photovoltaic array;

[0012] The sum of the sky scattered radiation, ground reflected radiation and direct radiation received by the back side of each cell in the bifacial photovoltaic module is calculated respectively to obtain the back side radiation distribution of the bifacial photovoltaic module.

[0013] In a possible implementation, calculating the irradiance received by each ground area according to the arrangement position, installation parameters and current sun position vector of the target photovoltaic array includes:

[0014] Projecting the current sun position vector in the three-dimensional space coordinate system onto a two-dimensional plane along the width direction of the target photovoltaic array according to the azimuth angle of the target photovoltaic array surface to obtain a two-dimensional sun position vector;

[0015] Calculate the two-dimensional sun position vector and the projection of the target photovoltaic array on a two-dimensional plane along the width direction of the target photovoltaic array according to the array surface inclination angle, the height of the array center relative to the ground, and the array width of the target photovoltaic array;

[0016] Determining a shielding coefficient of each section of the ground area according to the projection and the arrangement position of the target photovoltaic array;

[0017] The viewing angle coefficient of each ground area receiving sky scattering is determined, and the irradiance received by each ground area is calculated according to the shielding coefficient of each ground area and the viewing angle coefficient of the sky scattering.

[0018] In a possible implementation, determining the position of the target photovoltaic array in a two-dimensional Cartesian coordinate system, and determining a boundary of a support structure in the target photovoltaic array in the two-dimensional Cartesian coordinate system, includes:

[0019] Determining a line segment for representing a side cross-section of the target photovoltaic array according to the width of the target photovoltaic array and the inclination angle of the array surface;

[0020] Determine the position of the line segment in the two-dimensional Cartesian coordinate system as the position of the target photovoltaic array in the two-dimensional Cartesian coordinate system;

[0021] Determining a side cross-section of a support structure in the target photovoltaic array;

[0022] A boundary of the side cross-section of the support structure in the two-dimensional Cartesian coordinate system is determined as a boundary of the support structure in the two-dimensional Cartesian coordinate system.

[0023] In a possible implementation, the step of calculating, based on the position of the target photovoltaic array in the two-dimensional Cartesian coordinate system and the boundary of the support structure in the two-dimensional Cartesian coordinate system, the sky scattered radiation received by the portion of the back side of each cell in the bifacial photovoltaic assembly in the target photovoltaic array that is not blocked by the support structure, includes:

[0024] For each cell in the target photovoltaic array, determine the visible sky range on the back of the cell that is not blocked by the array according to the position of the target photovoltaic array in a two-dimensional Cartesian coordinate system;

[0025] Dividing the visible sky range into a plurality of first angle intervals;

[0026] determining, according to a boundary of the supporting structure in the two-dimensional Cartesian coordinate system, whether an incident light from the sky in each first angle interval is blocked by the supporting structure;

[0027] The accumulated value of the sky scattered radiation received at the first angle interval without any obstruction in the visible sky range is calculated to obtain the sky scattered radiation received by the back side of the solar cell from the visible sky range.

[0028] In a possible implementation, the calculating, based on the position of the target photovoltaic array in the two-dimensional Cartesian coordinate system, the boundary of the support structure in the two-dimensional Cartesian coordinate system, and the irradiance received by each segment of the ground area, the ground reflected irradiance received by the portion of the back side of each cell in the bifacial photovoltaic module that is not blocked by the support structure includes:

[0029] For each cell in the target photovoltaic array, determine the visible ground range of the back of the cell that is not blocked by the array according to the position of the target photovoltaic array in a two-dimensional Cartesian coordinate system;

[0030] Dividing the visible ground range into a plurality of second angle intervals respectively;

[0031] determining, according to a boundary of the supporting structure in the two-dimensional Cartesian coordinate system, whether an incident light reflected from the ground in each second angular interval is blocked by the supporting structure;

[0032] According to the irradiance received by each segment of the ground area, the accumulated value of the ground reflected irradiance received at the angle interval without any obstruction in the visible ground range is calculated to obtain the ground reflected irradiance received by the back side of the cell from the visible ground range.

[0033] In a possible implementation, after obtaining the back irradiance distribution of the bifacial photovoltaic module, the method for calculating the back irradiance distribution of the bifacial photovoltaic module further includes:

[0034] Calculate the total back irradiance of the bifacial photovoltaic module when it is shaded by the support structure according to the back irradiance distribution of the bifacial photovoltaic module;

[0035] Calculate the total back irradiance of the bifacial photovoltaic module without support structure shading;

[0036] The structural shadow coefficient of the bifacial photovoltaic assembly is calculated according to the total back side irradiance of the bifacial photovoltaic assembly when the supporting structure is shielded and the total back side irradiance of the bifacial photovoltaic assembly when the supporting structure is not shielded.

[0037] A second aspect of the present application provides a device for calculating the back irradiance distribution of a bifacial photovoltaic module, comprising:

[0038] A dividing unit, configured to divide a preset ground range in front of and behind the target photovoltaic array into n ground regions along a front-to-back direction according to the arrangement position of the target photovoltaic array, where n is a positive integer;

[0039] A first calculation unit, configured to calculate the irradiance received by each ground area according to the arrangement position, installation parameters and current sun position vector of the target photovoltaic array;

[0040] a determination unit, configured to determine a position of the target photovoltaic array in a two-dimensional Cartesian coordinate system, and to determine a boundary of a support structure in the target photovoltaic array in the two-dimensional Cartesian coordinate system;

[0041] A second calculation unit is used to calculate the sky scattered radiation received by the part of the back side of each cell in the bifacial photovoltaic assembly in the target photovoltaic array that is not blocked by the support structure according to the position of the target photovoltaic array in the two-dimensional Cartesian coordinate system and the boundary of the support structure in the two-dimensional Cartesian coordinate system;

[0042] A third calculation unit is used to calculate the ground reflected irradiance received by the portion of the back side of each cell in the bifacial photovoltaic assembly that is not blocked by the support structure according to the position of the target photovoltaic array in the two-dimensional Cartesian coordinate system, the boundary of the support structure in the two-dimensional Cartesian coordinate system, and the irradiance received by each segment of the ground area;

[0043] A fourth calculation unit, configured to calculate the direct radiation received by the back side of each cell in the bifacial photovoltaic module according to the arrangement position, installation parameters and current sun position vector of the target photovoltaic array;

[0044] The fifth calculation unit is used to respectively calculate the sum of the sky scattered radiation, ground reflected radiation and direct radiation received by the back side of each cell in the bifacial photovoltaic module to obtain the back side radiation distribution of the bifacial photovoltaic module.

[0045] A third aspect of the present application provides an electronic device, comprising at least one processor and a memory connected to the processor, wherein:

[0046] The memory is used to store computer programs;

[0047] The processor is used to execute the computer program so that the electronic device can implement the method for calculating the back side irradiance distribution of a bifacial photovoltaic module according to the first aspect or any implementation of the first aspect.

[0048] The fourth aspect of the present application provides a computer program product, including computer-readable instructions. When the computer-readable instructions are executed on an electronic device, the electronic device implements the method for calculating the back side irradiance distribution of a double-sided photovoltaic module according to the first aspect or any implementation method of the first aspect.

[0049] A fifth aspect of the present application provides a computer storage medium, which carries one or more computer programs. When the one or more computer programs are executed by an electronic device, the electronic device can implement the method for calculating the back side irradiance distribution of a double-sided photovoltaic module according to the first aspect or any implementation of the first aspect.

[0050] By means of the above-mentioned technical scheme, the present application provides a method for calculating the back-side irradiance distribution of a bifacial photovoltaic module and a related device, which fully considers the shadow shielding of the back side of the bifacial photovoltaic module by the supporting structure during the calculation process, thereby solving the problem of inaccurate calculation of the back-side irradiance distribution of the bifacial photovoltaic module under the shielding of the supporting structure. At the same time, by determining the position of the target photovoltaic array in the two-dimensional Cartesian coordinate system and the boundary of the supporting structure in the two-dimensional Cartesian coordinate system, the sky scattered radiation, ground reflected radiation and direct radiation received by the part of the back side of each cell in the bifacial photovoltaic module that is not shielded by the supporting structure are calculated, thereby realizing the calculation of the back-side irradiance distribution of the bifacial photovoltaic module in a two-dimensional scene, reducing the amount of calculation while maintaining high calculation accuracy and improving the calculation speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The above and other features, advantages and aspects of the embodiments of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. Throughout the accompanying drawings, the same or similar reference numerals represent the same or similar elements. It should be understood that the drawings are schematic and the originals and elements are not necessarily drawn to scale.

[0052] Figure 1 A schematic diagram of a system architecture provided for this application;

[0053] Figure 2 A schematic diagram of a terminal structure provided for this application;

[0054] Figure 3 A schematic diagram of a server structure provided for this application;

[0055] Figure 4 A schematic diagram of a flow chart of a method for calculating the back irradiation distribution of a bifacial photovoltaic module provided in an embodiment of the present application;

[0056] Figure 5 A schematic diagram of the geometric relationship between adjacent photovoltaic arrays provided in an embodiment of the present application;

[0057] Figure 6 A schematic diagram of the geometric relationship between the photovoltaic array and the supporting structure provided in the embodiment of the present application;

[0058] Figure 7 A schematic diagram of the receiving range of back scattered radiation of a photovoltaic array provided in an embodiment of the present application;

[0059] Figure 8 A schematic diagram of ground irradiance distribution calculation provided in an embodiment of the present application;

[0060] Fig. 9 A schematic diagram of the total irradiance distribution on the back side of a bifacial photovoltaic module shielded by a support structure provided in an embodiment of the present application;

[0061] Fig.10 A schematic diagram of the total irradiance distribution on the back side of a double-sided photovoltaic module without support structure shielding provided in an embodiment of the present application;

[0062] Fig.11 A schematic diagram of the structure of a device for calculating the back-side irradiance distribution of a double-sided photovoltaic module provided in an embodiment of the present application. DETAILED DESCRIPTION

[0063] The following describes the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. The terms used in the implementation method section of the present application are only used to explain the specific embodiments of the present application, and are not intended to limit the present application.

[0064] The embodiments of the present application are described below in conjunction with the accompanying drawings. Those skilled in the art will appreciate that, with the development of technology and the emergence of new scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0065] The terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and need not be used to describe a specific order or sequential order. It should be understood that the terms used in this way can be interchangeable under appropriate circumstances, which is only to describe the distinction mode adopted by the objects of the same attributes when describing in the embodiments of the present application. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, so that the process, method, system, product or equipment comprising a series of units need not be limited to those units, but may include other units that are not clearly listed or inherent to these processes, methods, products or equipment.

[0066] See also Figure 1 , Figure 1 A schematic diagram of a system architecture is shown. The system may include a terminal 100 and a server 200. The server 200 may include one or more servers ( Figure 1 In the example, a server is included, and the server 200 can provide the method for calculating the back irradiance distribution of a bifacial photovoltaic module provided in the embodiment of the present application to one or more terminals.

[0067] Among them, an application can be installed on the terminal 100, and the above application can provide an interface. The terminal 100 can receive relevant parameters entered by the user on the interface, such as the layout position and installation parameters of the photovoltaic array, and send the above parameters to the server 200. The server 200 can obtain processing results based on the received parameters, such as the irradiation distribution on the back side of the double-sided photovoltaic module, and return the processing results to the terminal 100.

[0068] It should be understood that in some optional implementations, the terminal 100 can also complete the action of obtaining the processing result based on the received parameters by itself without the cooperation of the server, and the embodiments of the present application are not limited to this.

[0069] Next describe Figure 1 The product form of the mid-terminal 100;

[0070] The terminal 100 in the embodiment of the present application can be a mobile phone, a tablet computer, a wearable device, an augmented reality (AR) / virtual reality (VR) device, a laptop computer, an ultra-mobile personal computer (UMPC), a netbook, a personal digital assistant (PDA), etc., and the embodiment of the present application does not impose any limitation on this.

[0071] Figure 2An optional hardware structure diagram of the terminal 100 is shown.

[0072] refer to Figure 2 As shown, the terminal 100 may include a radio frequency unit 110, a memory 120, an input unit 130, a display unit 140, a camera 150 (optional), an audio circuit 160 (optional), a speaker 161 (optional), a microphone 162 (optional), an earphone jack 163 (optional), a processor 170, an external interface 180, a power supply 190 and other components. Those skilled in the art will appreciate that Figure 2 This is merely an example of a terminal and does not constitute a limitation on the terminal. The terminal may include more or fewer components than shown in the figure, or a combination of certain components, or different components.

[0073] The input unit 130 can be used to receive input digital or character information, and generate key signal input related to the user settings and function control of the terminal. Specifically, the input unit 130 may include a touch screen 131 (optional) and / or other input devices 132. The touch screen 131 can collect the user's touch operations on or near it (such as the user's operation on or near the touch screen using any suitable object such as fingers, joints, stylus, etc.), and drive the corresponding connection device according to a pre-set program. The touch screen can detect the user's touch action on the touch screen, convert the touch action into a touch signal and send it to the processor 170, and can receive and execute the command sent by the processor 170; the touch signal at least includes the touch point coordinate information. The touch screen 131 can provide an input interface and an output interface between the terminal 100 and the user. In addition, the touch screen can be implemented using multiple types such as resistive, capacitive, infrared and surface acoustic wave. In addition to the touch screen 131, the input unit 130 can also include other input devices. Specifically, other input devices 132 may include, but are not limited to, one or more of a physical keyboard, function keys (such as a volume control key, a switch key, etc.), a trackball, a mouse, a joystick, and the like.

[0074] Among them, the input device 132 can receive input data and the like.

[0075] The display unit 140 can be used to display information input by the user or information provided to the user, various menus of the terminal 100, interactive interfaces, file display and / or playback of any multimedia file. In the embodiment of the present application, the display unit 140 can be used to display the interface for inputting parameters of the target photovoltaic array, the calculation and processing results of the back irradiation distribution of the bifacial photovoltaic modules in the target photovoltaic array, etc.

[0076] The memory 120 can be used to store instructions and data. The memory 120 can mainly include an instruction storage area and a data storage area. The data storage area can store various data, such as multimedia files, texts, etc.; the instruction storage area can store software units such as operating systems, applications, instructions required for at least one function, or their subsets and extensions. It can also include a non-volatile random access memory; provide the processor 170 with hardware, software and data resources including management of computing and processing equipment, and support control software and applications. It is also used for the storage of multimedia files, and the storage of running programs and applications.

[0077] The processor 170 is the control center of the terminal 100. It uses various interfaces and lines to connect various parts of the entire terminal 100. By running or executing instructions stored in the memory 120 and calling data stored in the memory 120, it executes various functions of the terminal 100 and processes data, thereby controlling the terminal device as a whole. Optionally, the processor 170 may include one or more processing units; preferably, the processor 170 may integrate an application processor and a modem processor, wherein the application processor mainly processes the operating system, user interface and application program, and the modem processor mainly processes wireless communication. It is understandable that the above-mentioned modem processor may not be integrated into the processor 170. In some embodiments, the processor and the memory may be implemented on a single chip, and in some embodiments, they may also be implemented separately on separate chips. The processor 170 may also be used to generate corresponding operation control signals, send them to corresponding components of the computing and processing device, read and process data in the software, especially read and process data and programs in the memory 120, so that each functional module therein performs corresponding functions, thereby controlling the corresponding components to act according to the requirements of the instructions.

[0078] Among them, the memory 120 can be used to store software codes related to the method for calculating the irradiance distribution on the back side of a bifacial photovoltaic module, the processor 170 can execute the steps of the method for calculating the irradiance distribution on the back side of a bifacial photovoltaic module, and can also schedule other units (such as the above-mentioned input unit 130 and the display unit 140) to achieve corresponding functions.

[0079] The radio frequency unit 110 (optional) can be used for receiving and sending information or receiving and sending signals during a call, for example, after receiving the downlink information of the base station, it is sent to the processor 170 for processing; in addition, the designed uplink data is sent to the base station. Generally, the RF circuit includes but is not limited to an antenna, at least one amplifier, a transceiver, a coupler, a low noise amplifier (Low Noise Amplifier, LNA), a duplexer, etc. In addition, the radio frequency unit 110 can also communicate with network devices and other devices through wireless communication. The wireless communication can use any communication standard or protocol, including but not limited to Global System of Mobile communication (Global System of Mobile communication, GSM), General Packet Radio Service (General Packet Radio Service, GPRS), Code Division Multiple Access (Code Division Multiple Access, CDMA), Wideband Code Division Multiple Access (Wideband Code Division Multiple Access, WCDMA), Long Term Evolution (Long Term Evolution, LTE), email, Short Messaging Service (SMS), etc.

[0080] In this embodiment of the present application, the RF unit 110 can send data to the server 200 and receive processing results sent by the server 200.

[0081] It should be understood that the radio frequency unit 110 is optional and can be replaced by other communication interfaces, such as a network port.

[0082] The terminal 100 also includes a power supply 190 (such as a battery) for supplying power to various components. Preferably, the power supply can be logically connected to the processor 170 through a power management system, so that the power management system can manage functions such as charging, discharging, and power consumption.

[0083] The terminal 100 further includes an external interface 180 , which may be a standard Micro USB interface or a multi-pin connector, and may be used to connect the terminal 100 to communicate with other devices, or to connect a charger to charge the terminal 100 .

[0084] Although not shown, the terminal 100 may also include a flashlight, a wireless fidelity (WiFi) module, a Bluetooth module, sensors with different functions, etc., which are not described in detail here. Some or all of the methods described below may be applied in the following embodiments. Figure 2 In the terminal 100 shown.

[0085] Next describe Figure 1 The product form of the server 200;

[0086] Figure 3 A structural diagram of a server 200 is provided, such as Figure 3 As shown, the server 200 includes a bus 201, a processor 202, a communication interface 203, and a memory 204. The processor 202, the memory 204, and the communication interface 203 communicate with each other via the bus 201.

[0087] The bus 201 may be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 3 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0088] The processor 202 may be any one or more of a central processing unit (CPU), a graphics processing unit (GPU), a microprocessor (MP), or a digital signal processor (DSP).

[0089] The memory 204 may include a volatile memory, such as a random access memory (RAM). The memory 204 may also include a non-volatile memory, such as a read-only memory (ROM), a flash memory, a hard disk drive (HDD), or a solid state drive (SSD).

[0090] Among them, the memory 204 can be used to store software codes related to the method for calculating the irradiance distribution on the back side of a bifacial photovoltaic module, and the processor 202 can execute the steps of the method for calculating the irradiance distribution on the back side of a bifacial photovoltaic module, and can also schedule other units to achieve corresponding functions.

[0091] It should be understood that the above-mentioned terminal 100 and server 200 can be centralized or distributed devices, and the processors in the above-mentioned terminal 100 and server 200 (such as processor 170 and processor 202) can be hardware circuits (such as application specific integrated circuit (ASIC), field-programmable gate array (FPGA), general-purpose processor, digital signal processor (DSP), microprocessor or microcontroller, etc.), or a combination of these hardware circuits. For example, the processor can be a hardware system with an instruction execution function, such as a CPU, DSP, etc., or a hardware system without an instruction execution function, such as an ASIC, FPGA, etc., or a combination of the above-mentioned hardware systems without an instruction execution function and hardware systems with an instruction execution function.

[0092] The embodiment of the present application provides a method for calculating the back irradiance distribution of a bifacial photovoltaic module. The method for calculating the back irradiance distribution of a bifacial photovoltaic module according to the embodiment of the present application is described in detail below in conjunction with the accompanying drawings.

[0093] Reference Figure 4 , Figure 4 A schematic diagram of a method for calculating the back irradiation distribution of a bifacial photovoltaic module provided in an embodiment of the present application is shown in FIG. Figure 4 As shown, a method for calculating the back irradiance distribution of a bifacial photovoltaic module provided in an embodiment of the present application may include steps 401 to 407, and these steps are described in detail below.

[0094] 401: Divide a preset ground range in front and behind the target photovoltaic array into n ground areas along the front-to-back direction according to the arrangement position of the target photovoltaic array;

[0095] For photovoltaic arrays, there are generally four situations for the arrangement of photovoltaic arrays:

[0096] Middle row array: There are PV arrays adjacent to the target PV array in both the front and rear rows;

[0097] First row array: There is no PV array adjacent to the target PV array in the front row, and there is a PV array adjacent to the target PV array in the back row;

[0098] Tail row array: There is a PV array adjacent to the target PV array in the front row, but there is no PV array adjacent to the target PV array in the back row;

[0099] Independent row array: There are no PV arrays adjacent to the target PV array in the front and rear rows.

[0100] In the process of calculating the irradiation distribution on the back side of a bifacial PV module, the front and rear rows of PV arrays will affect the irradiation reaching the back side of the bifacial PV module in the target PV array, which will be discussed separately later.

[0101] If the target photovoltaic array is a middle row array, the preset ground range before and after the target photovoltaic array includes the ground range between the target photovoltaic array and the front and rear rows of photovoltaic arrays;

[0102] If the target photovoltaic array is the front row array, the preset ground range before and after the target photovoltaic array includes the ground range between the target photovoltaic array and the rear row photovoltaic array and the preset ground range in front of the target photovoltaic array, and the width of the preset ground range in front of the target photovoltaic array is not less than the width between the two rows of photovoltaic arrays.

[0103] If the target photovoltaic array is the tail row array, the preset ground range before and after the target photovoltaic array includes the ground range between the target photovoltaic array and the front row photovoltaic array and the preset ground range behind the target photovoltaic array. The width of the preset ground range behind the target photovoltaic array is not less than the width between the two rows of photovoltaic arrays.

[0104] If the target photovoltaic array is an independent row array, the preset ground range before and after the target photovoltaic array includes the preset ground range before the target photovoltaic array and the preset ground range after the target photovoltaic array, and the width of the preset ground range before the target photovoltaic array and the width of the preset ground range after the target photovoltaic array are not less than the width between the two rows of photovoltaic arrays.

[0105] The preset ground range in front and behind the target photovoltaic array is divided into n ground areas along the front-to-back direction. The ground areas may be divided in equal proportion or not in equal proportion, which is not specifically limited in the present application.

[0106] 402: Calculate the irradiance received by each ground area according to the arrangement position, installation parameters and current sun position vector of the target photovoltaic array;

[0107] The installation parameters of the target photovoltaic array include the array surface inclination angle β a , array surface azimuth angle γ a , the height of the array center relative to the ground h a , array width w a and the array spacing d a .

[0108] The projection of each ground area is calculated according to the arrangement position, installation parameters and current sun position vector of the target photovoltaic array. The distribution pattern of the projection is different for different arrangement positions of the target photovoltaic array. The irradiance received by each ground area can be calculated according to the projection area. It should be noted that the direct irradiance of the ground area completely in the projection area is 0, but it may receive scattered radiation.

[0109] 403: Determine a position of a target photovoltaic array in a two-dimensional Cartesian coordinate system, and determine a boundary of a support structure in the target photovoltaic array in the two-dimensional Cartesian coordinate system;

[0110] A two-dimensional Cartesian coordinate system is established in advance. After the origin is determined, the horizontal direction is the X-axis and the vertical direction is the Y-axis. The two-dimensional Cartesian coordinate system is used to describe the position of the target photovoltaic array, the supporting structure, and the incident light.

[0111] 404: Calculate the sky diffuse radiation received by the portion of the back side of each cell in the bifacial photovoltaic module in the target photovoltaic array that is not shielded by the supporting structure according to the position of the target photovoltaic array in the two-dimensional Cartesian coordinate system and the boundary of the supporting structure in the two-dimensional Cartesian coordinate system;

[0112] The back side of each cell in a bifacial photovoltaic module can receive incident light from the sky. Based on the position of the target photovoltaic array in the two-dimensional Cartesian coordinate system and the boundary of the supporting structure in the two-dimensional Cartesian coordinate system, it can be determined whether the back side of the cell is blocked by the supporting structure when receiving incident light from the sky. In other words, the sky scattered radiation received by the part of the back side of each cell in the bifacial photovoltaic module that is not blocked by the supporting structure can be calculated.

[0113] 405: Calculate the ground reflected irradiance received by the portion of the back side of each cell in the bifacial photovoltaic module that is not shielded by the supporting structure, based on the position of the target photovoltaic array in the two-dimensional Cartesian coordinate system, the boundary of the supporting structure in the two-dimensional Cartesian coordinate system, and the irradiance received by each ground area;

[0114] The back side of each cell in a bifacial photovoltaic module can also receive incident light reflected from the ground. Based on the position of the target photovoltaic array in the two-dimensional Cartesian coordinate system and the boundary of the supporting structure in the two-dimensional Cartesian coordinate system, it can be determined whether the incident light reflected from the ground on the back side of the cell is blocked by the supporting structure. Combined with the irradiance received by each ground area, the irradiance reflected from the ground received by the back side of the cell that is not completely blocked by the supporting structure is determined, thereby calculating the ground reflected irradiance received by the part of the back side of each cell that is not blocked by the supporting structure.

[0115] 406: Calculate the direct radiation received by the back side of each cell in the bifacial photovoltaic module according to the arrangement position and installation parameters of the target photovoltaic array and the current sun position vector;

[0116] For some situations in a year, for a target photovoltaic array with a fixed inclination facing south (in the northern hemisphere), the sun may be incident from the back of the target photovoltaic array in the morning and evening. In this case, some solar cell units on the back of the target photovoltaic array will receive direct radiation.

[0117] Therefore, each cell in the bifacial PV module in the target PV array may or may not receive direct irradiation.

[0118] 407: Calculate the sum of the sky scattered radiation, ground reflected radiation and direct radiation received by the back side of each cell in the bifacial photovoltaic module respectively, and obtain the back side radiation distribution of the bifacial photovoltaic module.

[0119] The present embodiment discloses a method for calculating the back side irradiance distribution of a bifacial photovoltaic module. In the calculation process, the shadow shielding of the back side of the bifacial photovoltaic module by the supporting structure is fully considered, thereby solving the problem of inaccurate calculation of the back side irradiance distribution of the bifacial photovoltaic module when the supporting structure shields the back side of the bifacial photovoltaic module. At the same time, by determining the position of the target photovoltaic array in the two-dimensional Cartesian coordinate system and the boundary of the supporting structure in the two-dimensional Cartesian coordinate system, the sky scattered irradiance, ground reflected irradiance and direct irradiance received by the part of the back side of each cell in the bifacial photovoltaic module that is not shielded by the supporting structure are calculated, thereby realizing the calculation of the back side irradiance distribution of the bifacial photovoltaic module in the two-dimensional scene, reducing the amount of calculation while maintaining high calculation accuracy and improving the calculation speed.

[0120] In a possible implementation, in step 402 of the above embodiment, the method for calculating the irradiance received by each ground area includes the following steps 4021-4024:

[0121] 4021: Projecting the current sun position vector in the three-dimensional space coordinate system onto a two-dimensional plane along the width direction of the target photovoltaic array according to the azimuth angle of the target photovoltaic array surface to obtain a two-dimensional sun position vector;

[0122] According to the sun position algorithm, calculate the solar zenith angle θ at the current time z and the solar azimuth γ s , so according to the solar zenith angle θ z and the solar azimuth γ s Determine the current sun position vector in the three-dimensional space coordinate system Then according to the target photovoltaic array surface azimuth angle γ a , the three-dimensional sun position vector Projected onto a two-dimensional plane along the width of the target photovoltaic array to obtain a two-dimensional sun position vector Among them, the target photovoltaic array surface azimuth angle γ a It is the angle between the projection of the normal of the photovoltaic array plane on the horizontal plane and the north direction. Specifically, the azimuth is measured from the north direction, with the clockwise direction being positive and the counterclockwise direction being negative.

[0123] 4022: Calculate the two-dimensional sun position vector and the projection of the target photovoltaic array on the two-dimensional plane along the width direction of the target photovoltaic array according to the array surface inclination angle, the height of the array center relative to the ground and the array width of the target photovoltaic array;

[0124] According to the array surface inclination angle β of the target photovoltaic array a , the height of the array center relative to the ground h a and the array width w a , calculate the two-dimensional sun position vector The projection of the target photovoltaic array on a two-dimensional plane along the width of the array.

[0125] Where, the array surface inclination angle β a is the angle between the target PV array and the horizontal ground;

[0126] Array center relative to ground height h a is the vertical height of the geometric center point of the target photovoltaic array from the ground;

[0127] Array width w a is the lateral dimension of the target PV array. For a single vertically mounted module (1P), that is, the target PV array includes only one row of bifacial PV modules in the vertical direction, and the bifacial PV modules are mounted vertically, the array width is the length of the bifacial PV modules.

[0128] 4023: Determine the shielding coefficient of each ground area according to the projection and the arrangement position of the target photovoltaic array;

[0129] The distribution of projections varies depending on the location of the target photovoltaic array. For the middle row array, it is necessary to consider the shadow of the target photovoltaic array itself and the front and rear rows of arrays; for the first row array, it is necessary to consider the shadow of the target photovoltaic array itself and the rear rows of arrays; for the rear row array, it is necessary to consider the shadow of the target photovoltaic array itself and the front rows of arrays; for the independent row array, only the shadow of the target array itself needs to be considered.

[0130] According to the above projection calculation results, it is determined whether each ground area is blocked. If the ground area is blocked, the blocking coefficient K of the ground area is 0. If the ground area is not blocked, the blocking coefficient K of the ground area is the solar zenith angle θ. z If the ground area is partially blocked, the blocking coefficient K of the ground area is the solar zenith angle θ z The cosine of is multiplied by the proportion of the area that is not obscured.

[0131] 4024: Determine the viewing angle coefficient of each ground area receiving sky scattering, and calculate the irradiance received by each ground area according to the shielding coefficient of each ground area and the viewing angle coefficient of the sky scattering.

[0132] There are many methods for calculating the viewing angle coefficient of each ground area receiving sky scattering. In a possible implementation, the following steps A1-A2 are included:

[0133] A1: Determine the viewing angle boundaries of the photovoltaic arrays on both sides of the i-th ground area;

[0134] The viewing angle boundaries of the photovoltaic array are two boundary lines of the maximum angle range of the sky that can be seen from the gap between two rows of photovoltaic arrays when observing the sky from the i-th ground area. The i-th ground area corresponds to multiple photovoltaic array gaps.

[0135] A2: Calculate the two angles between the two boundary lines of the viewing angle boundary and the horizontal plane, and calculate the viewing angle coefficient of the i-th ground area receiving sky scattering based on the two angles.

[0136] Calculate the viewing angle coefficient F of the i-th ground area receiving sky scattering i,sky→ground The formula is:

[0137]

[0138] Where m is the number of PV array gaps that can see the sky when observing the sky from the i-th ground area, and j is the j-th gap among all PV array gaps. θ S2,j is the larger angle between the two boundary lines of the maximum angle range of the sky seen from the jth gap and the horizontal plane, θ S1,j For a smaller angle.

[0139] Then the irradiance E received by the i-th ground area is ground,i The calculation formula is as follows:

[0140] E ground,i =K·E bn +F i,sky→ground ·E dh ,i=1,2,...,n

[0141] Among them, E bn is the normal direct irradiance, E dh is the horizontal scattered irradiance, F i,sky→ground is the viewing angle coefficient of the i-th ground area receiving sky scattering, E bn and E dh It can be obtained by observing with existing instruments or by calculating with existing models, and this embodiment does not make any specific limitation.

[0142] In a possible implementation, step 403 in the above embodiment, determining the position of the target photovoltaic array in the two-dimensional Cartesian coordinate system, and determining the boundary of the support structure in the target photovoltaic array in the two-dimensional Cartesian coordinate system, includes the following steps 4031-4034:

[0143] 4031: determining a line segment for representing a side cross section of a target photovoltaic array according to a width of the target photovoltaic array and an inclination angle of an array surface;

[0144] 4032: Determine the position of the line segment in the two-dimensional Cartesian coordinate system as the position of the target photovoltaic array in the two-dimensional Cartesian coordinate system;

[0145] Assuming that the target photovoltaic array is infinitely long, the edge effect at both ends of the array is ignored, that is, the shading at both ends of the array is ignored, and only the geometric relationship and radiation characteristics of the middle part are concerned.

[0146] The plane where the side section of the target photovoltaic array is located is used as the plane where the two-dimensional Cartesian coordinate system is located, and a line segment of a fixed length is used to represent the side section of the target photovoltaic array. Figure 5 The schematic diagram of the geometric relationship between adjacent photovoltaic arrays is shown in Figure 1. Figure 5 The two oblique lines in the figure represent the side cross-sections of two adjacent rows of photovoltaic arrays. The array spacing d a is the horizontal distance between two adjacent rows of photovoltaic arrays, and the height of the array center relative to the ground h a is the vertical height of the geometric center point of the target photovoltaic array from the ground, where the line segment on the left side used to represent the side section of the target photovoltaic array is based on the width w of the target photovoltaic array. a and the array surface inclination angle β a The two endpoints of the line segment are determined to be P1 and P2, respectively, and the position of the target photovoltaic array in the two-dimensional Cartesian coordinate system can be determined through these two endpoints.

[0147] 4033: Determine the side cross-section of the support structure in the target photovoltaic array;

[0148] 4034: Determine the boundary of the side section of the support structure in the two-dimensional Cartesian coordinate system as the boundary of the support structure in the two-dimensional Cartesian coordinate system.

[0149] The main axis and main beam are the supporting structures that have the greatest impact on the back irradiation of the photovoltaic array. They are arranged along the length of the target photovoltaic array and are the same length or slightly longer than the photovoltaic array. Therefore, they can be simplified into a two-dimensional scene for analysis together with the target photovoltaic array.

[0150] The cross-sectional shape of the supporting structure is generally a rectangular module, a circular module or other special-shaped modules. The shape, position and quantity of the cross-sectional shape of the supporting structure are determined according to the actual size and layout design of the supporting structure.

[0151] like Figure 6 The schematic diagram of the geometric relationship between the photovoltaic array and the supporting structure shown in the figure, the shape of the cross-section of the supporting structure is a rectangular module, one side of the rectangular module is parallel to the target photovoltaic array, and the coordinates of the four vertices of the rectangular module in the two-dimensional Cartesian coordinate system can be determined by the coordinates of a vertex of the rectangular module and the width and height of the rectangle, and then the boundary of the rectangular module in the two-dimensional Cartesian coordinate system can be determined.

[0152] If the cross-sectional shape of the supporting structure is a circular module, the boundary of the circular module in the two-dimensional Cartesian coordinate system can be determined by only determining the radius and the coordinates of the center of the circular module in the two-dimensional Cartesian coordinate system.

[0153] If the cross-sectional shape of the supporting structure is a special-shaped module, the position and shape of the special-shaped module can be described by a set of special-shaped vertices, and the boundary of the special-shaped module in the two-dimensional Cartesian coordinate system can be determined by the coordinates of this set of vertices in the two-dimensional Cartesian coordinate system.

[0154] This embodiment converts the target photovoltaic array from a three-dimensional scene to a two-dimensional scene, and subsequently calculates the back irradiation distribution of the bifacial photovoltaic module in the two-dimensional scene, thereby reducing the amount of calculation and improving the calculation speed while maintaining high calculation accuracy.

[0155] In a possible implementation, step 404 in the above embodiment, calculating the sky diffuse radiation received by the portion of the back side of each cell in the bifacial photovoltaic module that is not blocked by the supporting structure, specifically includes the following steps 4041-4044 for each cell in the target photovoltaic array:

[0156] 4041: Determine the visible sky range on the back of the solar cell that is not blocked by the array according to the position of the target photovoltaic array in the two-dimensional Cartesian coordinate system;

[0157] First, according to the layout of the double-sided photovoltaic modules used in the target photovoltaic array, the number of cells along the width of the array is confirmed. For example, for a single vertically installed module, the number of cells along the width of the array is 24. Then, according to the position of the target photovoltaic array in the two-dimensional Cartesian coordinate system, the coordinate position of each cell in the two-dimensional Cartesian coordinate plane can be derived. Since the width of the cell is small, the center point of the cell can be used to represent the position of the cell.

[0158] According to the target photovoltaic array surface inclination angle β a , array width w a and the array spacing d a , combined with the arrangement position of the target photovoltaic array in the photovoltaic array, determine the visible sky range on the back of each cell in the target photovoltaic array.

[0159] If the target PV array is the middle row array or the first row array, Figure 7 The schematic diagram of the back scattered radiation receiving range of the photovoltaic array shown in the figure, let the upper endpoint of the target photovoltaic array be P1, the lower endpoint be P2, the upper endpoint of the rear array of the target photovoltaic array be P1', the lower endpoint be P2', take the upper endpoint of the back of the target photovoltaic array as the starting point 0°, and the lower endpoint as the end point 180°, and then judge the visible sky range 0°~α of the back of the pth solar cell unit that is not blocked by the array according to the geometric relationship. sky,p α sky,p The angle is: the angle formed by taking the midpoint of the pth solar cell as the vertex, and taking the upper endpoint P1' of the rear array and the upper endpoint P1 of the target photovoltaic array as the two end points.

[0160] If the target PV array is the tail row array or an independent row array, and there is no adjacent PV array in the rear row, α sky,p The midpoint of the p-th cell is taken as the vertex, one side is the line connecting the midpoint of the p-th cell and the upper end point P1 of the target photovoltaic array, and the other side is the horizontal ray from the midpoint of the p-th cell to the rear side.

[0161] 4042: Divide the visible sky range into a plurality of first angle intervals;

[0162] In order to more accurately analyze the scattered radiation received by the visible sky range of each cell, an angle interval Δα is defined, and the visible sky range of each cell is 0° to α sky,p The system is evenly divided into sections according to Δα to obtain a plurality of first angle intervals.

[0163] 4043: Determine whether incident light from the sky in each first angle interval is blocked by the supporting structure according to a boundary of the supporting structure in the two-dimensional Cartesian coordinate system;

[0164] For each first angle interval, calculate the incident light within the angle range, and let the midpoint of the pth cell be C p , the upper endpoint of the target photovoltaic array is P1, for the uth first angle interval θ within the visible sky range u (where θ u =u·Δα, u is an integer), calculate C p Starting from, and line segment C p P1 into θ u The angle of the ray, θ u of incident light.

[0165] For each incident light ray, according to the boundary of the supporting structure in the two-dimensional Cartesian coordinate system, a geometric method corresponding to the shape of the side cross section of the supporting structure is used to determine whether the incident light ray intersects with the supporting structure. If both intersect, the incident light ray from the sky in the first angle interval is blocked by the supporting structure, otherwise the incident light ray is not blocked. If the incident light ray from the sky in the first angle interval is blocked by the supporting structure, the blocking coefficient M of the first angle interval is 0, and if it is not blocked, the blocking coefficient M of the first angle interval is 1.

[0166] 4044: Calculate the cumulative value of the sky scattered radiation received at the first angle interval without any obstruction in the visible sky range, and obtain the sky scattered radiation received by the back side of the solar cell from the visible sky range.

[0167] The sky scattered radiation E received by the back of the pth cell from the visible sky range d，sky，p The calculation formula is as follows:

[0168]

[0169] Among them, the uth first angle θ u View factor F for receiving sky scattering u,sky→cell There are many calculation methods, for example, F u,sky→cell The calculation formula is as follows:

[0170] F u,sky→cell =(cosθ u-1 -cosθ u ) / 2

[0171] cosθ u-1 is the u-1 first angle.

[0172] In a possible implementation, step 405 in the above embodiment, calculating the ground reflected irradiance received by the portion of the back side of each cell in the bifacial photovoltaic module that is not blocked by the supporting structure, specifically includes the following steps 4051-4054 ​​for each cell in the target photovoltaic array:

[0173] 4051: Determine the visible ground range of the back of the solar cell that is not blocked by the array according to the position of the target photovoltaic array in the two-dimensional Cartesian coordinate system;

[0174] If the target PV array is the middle row array or the first row array, Figure 7The schematic diagram of the back scattered radiation receiving range of the target photovoltaic array is shown in FIG. The upper endpoint of the target photovoltaic array is P1, the lower endpoint is P2, the upper endpoint of the rear array of the target photovoltaic array is P1', the lower endpoint is P2', the upper endpoint of the back of the target photovoltaic array is 0° as the starting point, and the lower endpoint is 180° as the end point, and then the visible ground range α of the back of the pth solar cell unit that is not blocked by the array is determined according to the geometric relationship ground,p ~180°. ground,p The angle is: the angle formed by taking the midpoint of the pth solar cell as the vertex, the lower endpoint P2' of the rear array and the upper endpoint P1 of the target photovoltaic array as the two end points.

[0175] If the target PV array is the tail row array or an independent row array, and there is no adjacent PV array in the rear row, α ground,p The midpoint of the p-th cell is taken as the vertex, one side is the line connecting the midpoint of the p-th cell and the upper end point P1 of the target photovoltaic array, and the other side is the horizontal ray from the midpoint of the p-th cell to the rear side.

[0176] 4052: Divide the visible ground range into a plurality of second angle intervals;

[0177] Similar to the visible sky range, in order to more accurately analyze the ground reflected irradiance received by the visible ground range of each cell, an angle interval Δα is defined, and the visible sky range α of each cell is divided into ground,p ~180° is evenly divided into segments according to Δα to obtain multiple second angle intervals.

[0178] 4053: Determine, according to the boundary of the supporting structure in the two-dimensional Cartesian coordinate system, whether the incident light reflected from the ground in each second angle interval is blocked by the supporting structure;

[0179] For each second angle interval, calculate the incident light within the angle range, and let the midpoint of the pth cell be C p , the upper endpoint of the target photovoltaic array is P1, for the vth second angle interval θ within the visible ground range v (where θ v =α ground，p +v·Δα, v is an integer), calculate C p Starting from, with line segment C p P1 into θ v The angle of the ray, θ v of incident light.

[0180] For each incident light ray, according to the boundary of the supporting structure in the two-dimensional Cartesian coordinate system, a geometric method corresponding to the shape of the side cross section of the supporting structure is used to determine whether the incident light ray intersects with the supporting structure. If both intersect, the incident light ray reflected from the ground in the second angle interval is blocked by the supporting structure, otherwise the incident light ray is not blocked. If the incident light ray reflected from the ground in the second angle interval is blocked by the supporting structure, the blocking coefficient M of the second angle interval is 0, and if it is not blocked, the blocking coefficient M of the second angle interval is 1.

[0181] 4054: Based on the irradiance received by each ground area, the cumulative value of the ground reflected irradiance received at the angle interval without any obstruction in the visible ground range is calculated to obtain the ground reflected irradiance received by the back side of the cell from the visible ground range.

[0182] The ground reflected radiation E received by the back of the pth cell from the visible ground range d，ground，p The calculation formula is as follows:

[0183]

[0184] Where ρ is the surface albedo, F v,ground→cell is the vth second angle θ v View factor for receiving ground reflection, E ground,v is the corresponding ground irradiance.

[0185] The vth second angle θ v View factor F for receiving ground reflection v,ground→cell There are many methods for calculating the viewing angle coefficient, one of which is F v,ground→cell The calculation method is as follows:

[0186] F v,ground→cell =(cosθ v-1 -cosθ v ) / 2

[0187] Among them, cosθ v-1 is v-1 second angle. ground,v Can be the vth second angle θ v The average irradiance received by all ground areas within the viewing angle range.

[0188] In a possible implementation, step 406 in the above embodiment, calculating the direct radiation received by the back side of each cell in the bifacial photovoltaic module, specifically includes:

[0189] According to the array surface inclination angle β of the photovoltaic array a Calculate the target photovoltaic array back normal vector using the array surface azimuth angle γa Solve for the three-dimensional sun position vector If α<90°, it means that the sun is incident from the back of the target photovoltaic array at this time. The calculation formula for the direct irradiance reaching the back of the target photovoltaic array at this time is as follows:

[0190] E b,back =E bn ·cosα.

[0191] In addition, for the middle and first row arrays, it is also necessary to consider the shielding of the rear row arrays from direct sunlight. According to the two-dimensional sun position vector The projection range of the rear array on the target photovoltaic array is calculated by geometric method, and the direct shielding coefficient N is set. The direct shielding coefficient of the solar cells outside the projection range is 1, and they can receive direct radiation from the back side. The direct shielding coefficient of the solar cells within the projection range is 0, and they cannot receive direct radiation from the back side. The direct radiation calculation formula of the back side of the target photovoltaic array is N·E b，back .

[0192] On this basis, the total back irradiance E of the bifacial photovoltaic module under the shading of the supporting structure is back，p The calculation formula is as follows:

[0193]

[0194] In the field of power generation performance simulation and evaluation of bifacial photovoltaic systems, the structural shadow coefficient is used to represent the proportion of irradiation loss caused by the shading of the back of the bifacial photovoltaic module by the back support structure of the photovoltaic module. The support structure that has the greatest impact on the shading of the back of the photovoltaic array is the main axis or main beam. For tracking photovoltaic arrays, a main axis is usually installed at the center of the array to support the rotation of the tracking array; for fixed-angle photovoltaic arrays, multiple main beams may be installed horizontally on the back of the photovoltaic array to ensure the stability and strength of the structure.

[0195] According to the back irradiation distribution of the bifacial photovoltaic module, the total back irradiation E of the bifacial photovoltaic module under the shading of the supporting structure can be calculated. back,p,shading According to the above calculation method of the back irradiation distribution of the bifacial photovoltaic module, the total back irradiation E of the bifacial photovoltaic module without supporting structure shading can also be calculated without considering the supporting structure shading. back,p,noshading , according to the total back irradiance E of the bifacial photovoltaic module under the shading of the supporting structure back,p,shading The total back irradiance E of a bifacial photovoltaic module without support structure shading back,p,noshading , calculate the structural shadow coefficient f of the bifacial photovoltaic module s , the specific calculation formula is as follows:

[0196]

[0197] Get the structural shadow coefficient f sAfter that, it can be used for the simulation and evaluation of the power generation performance of the bifacial photovoltaic system, so as to obtain more accurate simulation results of the power generation performance of the bifacial photovoltaic system. It can also be used to simulate and evaluate the power generation performance of different support structures, so as to achieve the purpose of optimizing the support structure. At the same time, for the bifacial photovoltaic tracking system, it can be rotated according to the optimal angle of bifacial irradiation through the intelligent tracking algorithm. After quickly and accurately obtaining the total irradiation distribution on the back of the bifacial component after considering the structural shading, the total bifacial irradiation at each tracking angle can be more accurately calculated. Ultimately, this will help obtain a more accurate optimal angle of bifacial irradiation, thereby improving the performance of the intelligent tracking algorithm and the overall power generation efficiency of the system.

[0198] The effects of the embodiments of the present application are described below through a specific example.

[0199] like Figure 5 An example diagram of the geometric relationship of a double-sided photovoltaic array is shown in FIG. Figure 5 The two oblique lines in the figure represent the side sections of two adjacent rows of photovoltaic arrays. The inclination angle β of the array surface can be obtained from the content in the figure. a , the height of the array center relative to the ground h a , array width w a and the array spacing d a Specifically represents the size parameters and geometric relationships.

[0200] Figure 8 This is a schematic diagram of ground irradiation distribution calculation. Through the content in the figure, we can get the two-dimensional sun position vector at a certain moment. And the projection of the photovoltaic array on the two-dimensional plane along the width of the array. The ground area at the projection position in the figure is blocked, and the blockage coefficient K is 0. The unblocked ground area has a blockage coefficient K of cosθ z , and the angle θ between the two boundary lines of a ground area and the horizontal plane can be obtained S1 ,θ S2 , and then the viewing angle coefficient of the ground area receiving sky scattering can be calculated.

[0201] Figure 6 It is a schematic diagram of the geometric relationship between the photovoltaic array and the supporting structure. The specific geometric relationship between the photovoltaic array and the supporting structure, as well as the boundary of the supporting structure, can be determined in a two-dimensional Cartesian coordinate system.

[0202] Figure 7 This is a schematic diagram of the back scattered radiation receiving range of a bifacial photovoltaic module. sky,p , α ground,p are the visible sky range and visible ground range of the cell p, respectively, sky,shadow,p is the range of the visible sky of the cell p that is blocked by the supporting structure, α ground,shadow,pIt is the range of the visible ground of the solar cell p that is blocked by the supporting structure. The back shielding coefficient M of the incident rays in the range blocked by the supporting structure is 0.

[0203] Fig. 9 and Fig.10 The total back irradiation distribution diagrams are respectively with and without support structure shielding. The longitude of the photovoltaic site is 117.12°E, the latitude is 31.77°N, and the calculation time is 15:04 on March 20, Beijing time. The photovoltaic array is a flat single-axis tracking array with an array surface inclination angle β a is 45°, and the array surface azimuth angle γ a is 270°, and the array width w a is 2.278m, and the height of the array center relative to the ground is h a is 1.6m, array spacing d a In addition, the solar zenith angle is 50.46°, the solar azimuth angle is 238.43°, and the normal direct irradiance is 413W / m 2 , the horizontal scattered irradiance is 188W / m 2 , the surface albedo is 0.2.

[0204] pass Fig. 9 and Fig.10 It can be clearly seen that the irradiance of the cells near the supporting structure is significantly reduced. The structural shadow coefficient fs can be calculated based on the total back irradiance distribution without shading:

[0205]

[0206] Wherein, P is the number of battery cells.

[0207] Compared with the prior art, the method for calculating the back irradiation distribution of a double-sided photovoltaic module provided in an embodiment of the present application solves the problem of inaccurate back irradiation calculation of a double-sided photovoltaic array when the main supporting structure such as the main shaft or the main beam is blocked, and also overcomes the difficulty of the huge amount of calculation required for high-precision simulation methods. By fully considering the shadow shielding effect of the installation of the main shaft or the main beam on the back of the double-sided photovoltaic module, the method for calculating the back irradiation distribution of a double-sided photovoltaic module provided in an embodiment of the present application also designs an efficient and simplified two-dimensional scene calculation method. This method achieves fast calculation while maintaining high accuracy, and is suitable for real-time monitoring and rapid evaluation of large-scale projects. Based on accurate back irradiation distribution information, the power station design can be optimized to maximize the use of solar energy resources, thereby improving the economic benefits of the entire power station.

[0208] In addition, the method provided in the embodiment of the present application is easy to integrate into the existing photovoltaic power generation system management and optimization software, providing users with instant data support. It can not only effectively deal with the situation where a single main axis is located in the middle of the back of the array, but also can be flexibly applied to more complex fixed photovoltaic array support structure layouts such as multiple main beams, and has a wide range of applications.

[0209] A method for calculating the back side irradiance distribution of a bifacial photovoltaic module provided in an embodiment of the present application is introduced above. A device for executing the method for calculating the back side irradiance distribution of a bifacial photovoltaic module is introduced below.

[0210] See also Fig.11 , Fig.11 This is a schematic diagram of the structure of a device for calculating the back irradiation distribution of a double-sided photovoltaic module provided in an embodiment of the present application. Fig.11 As shown, the device for calculating the back irradiance distribution of a double-sided photovoltaic module comprises:

[0211] A division unit 1101 is used to divide a preset ground range in front of and behind the target photovoltaic array into n ground areas along the front-to-back direction according to the arrangement position of the target photovoltaic array, where n is a positive integer;

[0212] A first calculation unit 1102 is used to calculate the irradiance received by each ground area according to the arrangement position, installation parameters and current sun position vector of the target photovoltaic array;

[0213] A determination unit 1103 is used to determine the position of the target photovoltaic array in a two-dimensional Cartesian coordinate system, and determine the boundary of the support structure in the target photovoltaic array in the two-dimensional Cartesian coordinate system;

[0214] A second calculation unit 1104 is used to calculate the sky scattered radiation received by the portion of the back side of each cell in the bifacial photovoltaic assembly in the target photovoltaic array that is not blocked by the support structure according to the position of the target photovoltaic array in the two-dimensional Cartesian coordinate system and the boundary of the support structure in the two-dimensional Cartesian coordinate system;

[0215] The third calculation unit 1105 is used to calculate the ground reflected irradiance received by the portion of the back side of each cell in the bifacial photovoltaic module that is not blocked by the support structure according to the position of the target photovoltaic array in the two-dimensional Cartesian coordinate system, the boundary of the support structure in the two-dimensional Cartesian coordinate system, and the irradiance received by each segment of the ground area;

[0216] The fourth calculation unit 1106 is used to calculate the direct radiation received by the back side of each cell in the bifacial photovoltaic module according to the arrangement position, installation parameters and current sun position vector of the target photovoltaic array;

[0217] The fifth calculation unit 1107 is used to respectively calculate the sum of the sky scattered radiation, ground reflected radiation and direct radiation received by the back side of each cell in the bifacial photovoltaic module to obtain the back side radiation distribution of the bifacial photovoltaic module.

[0218] In a possible implementation, the first calculation unit is specifically used to project the current sun position vector in the three-dimensional space coordinate system to a two-dimensional plane along the width direction of the target photovoltaic array according to the azimuth angle of the target photovoltaic array surface to obtain a two-dimensional sun position vector; calculate the two-dimensional sun position vector and the projection of the target photovoltaic array on the two-dimensional plane along the width direction of the target photovoltaic array according to the array surface inclination angle of the target photovoltaic array, the height of the array center relative to the ground, and the array width; determine the shielding coefficient of each section of the ground area according to the projection and the arrangement position of the target photovoltaic array; determine the viewing angle coefficient of each section of the ground area receiving sky scattering, and calculate the irradiance received by each section of the ground area according to the shielding coefficient of each section of the ground area and the viewing angle coefficient of receiving sky scattering.

[0219] In a possible implementation, the determination unit is specifically used to determine a line segment used to represent a side section of the target photovoltaic array based on the width of the target photovoltaic array and the inclination angle of the array surface; determine the position of the line segment in a two-dimensional Cartesian coordinate system as the position of the target photovoltaic array in the two-dimensional Cartesian coordinate system; determine the side section of a support structure in the target photovoltaic array; and determine the boundary of the side section of the support structure in the two-dimensional Cartesian coordinate system as the boundary of the support structure in the two-dimensional Cartesian coordinate system.

[0220] In a possible implementation, the second calculation unit is specifically used to determine, for each cell in the target photovoltaic array, the visible sky range on the back of the cell that is not blocked by the array according to the position of the target photovoltaic array in the two-dimensional Cartesian coordinate system; divide the visible sky range into multiple first angle intervals; determine whether the incident light from the sky in each first angle interval is blocked by the supporting structure according to the boundary of the supporting structure in the two-dimensional Cartesian coordinate system; calculate the cumulative value of the sky scattered radiation received in the first angle interval where there is no obstruction in the visible sky range, and obtain the sky scattered radiation received by the back of the cell from the visible sky range.

[0221] In a possible implementation, the third calculation unit is specifically used to determine, for each cell in the target photovoltaic array, the visible ground range where the back of the cell is not blocked by the array according to the position of the target photovoltaic array in the two-dimensional Cartesian coordinate system; divide the visible ground range into multiple second angle intervals; determine, according to the boundary of the supporting structure in the two-dimensional Cartesian coordinate system, whether the incident light reflected from the ground in each of the second angle intervals is blocked by the supporting structure; and calculate, according to the irradiance received by each segment of the ground area, the cumulative value of the ground reflected irradiance received at the angle interval where there is no obstruction in the visible ground range, to obtain the ground reflected irradiance received by the back of the cell from the visible ground range.

[0222] In a possible implementation, the device for calculating the back irradiance distribution of a bifacial photovoltaic module further includes:

[0223] The sixth calculation unit is used to calculate the total back irradiation of the bifacial photovoltaic module when it is shaded by a supporting structure according to the back irradiation distribution of the bifacial photovoltaic module; calculate the total back irradiation of the bifacial photovoltaic module when it is not shaded by a supporting structure; calculate the structural shadow coefficient of the bifacial photovoltaic module according to the total back irradiation of the bifacial photovoltaic module when it is shaded by a supporting structure and the total back irradiation of the bifacial photovoltaic module when it is not shaded by a supporting structure.

[0224] The present embodiment discloses a device for calculating the back-side irradiance distribution of a bifacial photovoltaic module. In the calculation process, the shadow shielding of the back side of the bifacial photovoltaic module by the supporting structure is fully considered, thereby solving the problem of inaccurate calculation of the back-side irradiance distribution of the bifacial photovoltaic module when the supporting structure shields the back side of the bifacial photovoltaic module. At the same time, by determining the position of the target photovoltaic array in the two-dimensional Cartesian coordinate system and the boundary of the supporting structure in the two-dimensional Cartesian coordinate system, the sky scattered irradiance, ground reflected irradiance and direct irradiance received by the part of the back side of each cell in the bifacial photovoltaic module that is not shielded by the supporting structure are calculated, thereby realizing the calculation of the back-side irradiance distribution of the bifacial photovoltaic module in a two-dimensional scene, reducing the amount of calculation while maintaining high calculation accuracy and improving the calculation speed.

[0225] An electronic device is also provided in an embodiment of the present application. The electronic device may be the above-mentioned terminal 100 or server 200, and the electronic device includes at least one processor and a memory connected to the processor, wherein:

[0226] The memory is used to store computer programs;

[0227] The processor is used to execute the computer program so that the electronic device can implement any method for calculating the back side irradiance distribution of a bifacial photovoltaic module provided in the embodiments of the present application.

[0228] An embodiment of the present application also provides a computer program product including computer-readable instructions. When the computer-readable instructions are executed on an electronic device, the electronic device implements any method for calculating the back-side irradiance distribution of a bifacial photovoltaic module provided in the embodiment of the present application.

[0229] A computer-readable storage medium is also provided in an embodiment of the present application. The storage medium carries one or more computer programs. When one or more computer programs are executed by an electronic device, the electronic device can implement any method for calculating the back-side irradiance distribution of a bifacial photovoltaic module provided in an embodiment of the present application.

[0230] It should also be noted that the device embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed over multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. In addition, in the drawings of the device embodiments provided by the present application, the connection relationship between the modules indicates that there is a communication connection between them, which may be specifically implemented as one or more communication buses or signal lines.

[0231] Through the description of the above implementation mode, the technicians in the field can clearly understand that the present application can be implemented by means of software plus necessary general hardware, and of course, it can also be implemented by special hardware including special integrated circuits, special CPUs, special memories, special components, etc. In general, all functions completed by computer programs can be easily implemented by corresponding hardware, and the specific hardware structure used to implement the same function can also be various, such as analog circuits, digital circuits or special circuits. However, for the present application, software program implementation is a better implementation mode in more cases. Based on such an understanding, the technical solution of the present application is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a readable storage medium, such as a computer floppy disk, a U disk, a mobile hard disk, a ROM, a RAM, a disk or an optical disk, etc., including a number of instructions to enable a computer device (which can be a personal computer, a training device, or a network device, etc.) to execute the methods described in each embodiment of the present application.

[0232] In the above embodiments, all or part of the embodiments may be implemented by software, hardware, firmware or any combination thereof. When implemented by software, all or part of the embodiments may be implemented in the form of a computer program product.

[0233] The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from a website site, a computer, a training device, or a data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, training device, or data center. The computer-readable storage medium may be any available medium that a computer can store or a data storage device such as a training device, a data center, etc. that includes one or more available media integrations. The available medium may be a magnetic medium, (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state drive (SSD)), etc.

Claims

1. A method for calculating the back irradiance distribution of a bifacial photovoltaic module, characterized in that: include: According to the arrangement position of the target photovoltaic array, the preset ground range in front and behind the target photovoltaic array is divided into n ground areas along the front-to-back direction, where n is a positive integer; Calculating the irradiance received by each ground area according to the arrangement position, installation parameters and current sun position vector of the target photovoltaic array; Determine the position of the target photovoltaic array in a two-dimensional Cartesian coordinate system, and determine the boundary of the support structure in the target photovoltaic array in the two-dimensional Cartesian coordinate system; Calculate the sky scattered radiation received by the portion of the back side of each cell in the bifacial photovoltaic assembly in the target photovoltaic array that is not shielded by the support structure according to the position of the target photovoltaic array in the two-dimensional Cartesian coordinate system and the boundary of the support structure in the two-dimensional Cartesian coordinate system; Calculate the ground reflected irradiance received by the portion of the back side of each cell in the bifacial photovoltaic module that is not blocked by the support structure according to the position of the target photovoltaic array in the two-dimensional Cartesian coordinate system, the boundary of the support structure in the two-dimensional Cartesian coordinate system, and the irradiance received by each segment of the ground area; Calculate the direct radiation received by the back side of each cell in the bifacial photovoltaic module according to the arrangement position, installation parameters and current sun position vector of the target photovoltaic array; The sum of the sky scattered radiation, ground reflected radiation and direct radiation received by the back side of each cell in the bifacial photovoltaic module is calculated respectively to obtain the back side radiation distribution of the bifacial photovoltaic module.

2. The method for calculating the back irradiance distribution of a bifacial photovoltaic module according to claim 1, characterized in that: The step of calculating the irradiance received by each ground area according to the arrangement position, installation parameters and current sun position vector of the target photovoltaic array includes: Projecting the current sun position vector in the three-dimensional space coordinate system onto a two-dimensional plane along the width direction of the target photovoltaic array according to the azimuth angle of the target photovoltaic array surface to obtain a two-dimensional sun position vector; Calculate the two-dimensional sun position vector and the projection of the target photovoltaic array on a two-dimensional plane along the width direction of the target photovoltaic array according to the array surface inclination angle, the height of the array center relative to the ground, and the array width of the target photovoltaic array; Determining a shielding coefficient of each section of the ground area according to the projection and the arrangement position of the target photovoltaic array; The viewing angle coefficient of each ground area receiving sky scattering is determined, and the irradiance received by each ground area is calculated according to the shielding coefficient of each ground area and the viewing angle coefficient of the sky scattering.

3. The method for calculating the back irradiance distribution of a bifacial photovoltaic module according to claim 1, characterized in that: The determining of the position of the target photovoltaic array in a two-dimensional Cartesian coordinate system and the determination of the boundary of the support structure in the target photovoltaic array in the two-dimensional Cartesian coordinate system comprises: Determining a line segment for representing a side cross-section of the target photovoltaic array according to the width of the target photovoltaic array and the inclination angle of the array surface; Determine the position of the line segment in the two-dimensional Cartesian coordinate system as the position of the target photovoltaic array in the two-dimensional Cartesian coordinate system; Determining a side cross-section of a support structure in the target photovoltaic array; A boundary of the side cross-section of the support structure in the two-dimensional Cartesian coordinate system is determined as a boundary of the support structure in the two-dimensional Cartesian coordinate system.

4. The method for calculating the back irradiance distribution of a bifacial photovoltaic module according to claim 1, characterized in that: The step of calculating, based on the position of the target photovoltaic array in the two-dimensional Cartesian coordinate system and the boundary of the support structure in the two-dimensional Cartesian coordinate system, the sky scattered radiation received by a portion of the back side of each cell in the bifacial photovoltaic assembly in the target photovoltaic array that is not shielded by the support structure, comprises: For each cell in the target photovoltaic array, determine the visible sky range on the back of the cell that is not blocked by the array according to the position of the target photovoltaic array in a two-dimensional Cartesian coordinate system; Dividing the visible sky range into a plurality of first angle intervals; determining, according to a boundary of the supporting structure in the two-dimensional Cartesian coordinate system, whether an incident light from the sky in each first angle interval is blocked by the supporting structure; The accumulated value of the sky scattered radiation received at the first angle interval without any obstruction in the visible sky range is calculated to obtain the sky scattered radiation received by the back side of the solar cell from the visible sky range.

5. The method for calculating the back irradiance distribution of a bifacial photovoltaic module according to claim 1, characterized in that: The method of calculating the ground reflected irradiance received by a portion of the back side of each cell in the bifacial photovoltaic assembly that is not shielded by the support structure according to the position of the target photovoltaic array in the two-dimensional Cartesian coordinate system, the boundary of the support structure in the two-dimensional Cartesian coordinate system, and the irradiance received by each segment of the ground area comprises: For each cell in the target photovoltaic array, determine the visible ground range of the back of the cell that is not blocked by the array according to the position of the target photovoltaic array in a two-dimensional Cartesian coordinate system; Dividing the visible ground range into a plurality of second angle intervals respectively; determining, according to a boundary of the supporting structure in the two-dimensional Cartesian coordinate system, whether an incident light reflected from the ground in each second angular interval is blocked by the supporting structure; According to the irradiance received by each segment of the ground area, the accumulated value of the ground reflected irradiance received at the angle interval without any obstruction in the visible ground range is calculated to obtain the ground reflected irradiance received by the back side of the cell from the visible ground range.

6. The method for calculating the back irradiance distribution of a bifacial photovoltaic module according to claim 1, characterized in that: After obtaining the back irradiance distribution of the bifacial photovoltaic module, the method for calculating the back irradiance distribution of the bifacial photovoltaic module further includes: Calculate the total back irradiance of the bifacial photovoltaic module when it is shaded by the support structure according to the back irradiance distribution of the bifacial photovoltaic module; Calculate the total back irradiance of the bifacial photovoltaic module without support structure shading; The structural shadow coefficient of the bifacial photovoltaic assembly is calculated according to the total back side irradiance of the bifacial photovoltaic assembly when the supporting structure is shielded and the total back side irradiance of the bifacial photovoltaic assembly when the supporting structure is not shielded.

7. A device for calculating the back irradiance distribution of a bifacial photovoltaic module, characterized in that: include: A dividing unit, configured to divide a preset ground range in front of and behind the target photovoltaic array into n ground regions along a front-to-back direction according to the arrangement position of the target photovoltaic array, where n is a positive integer; A first calculation unit, configured to calculate the irradiance received by each ground area according to the arrangement position, installation parameters and current sun position vector of the target photovoltaic array; a determination unit, configured to determine a position of the target photovoltaic array in a two-dimensional Cartesian coordinate system, and to determine a boundary of a support structure in the target photovoltaic array in the two-dimensional Cartesian coordinate system; The second calculation unit is used to calculate the position of each cell in the bifacial photovoltaic assembly in the target photovoltaic array according to the position of the target photovoltaic array in the two-dimensional Cartesian coordinate system and the boundary of the support structure in the two-dimensional Cartesian coordinate system. The scattered radiation from the sky is received by the portion of the back side of the sheet that is not blocked by the support structure; A third calculation unit is used to calculate the ground reflected irradiance received by the portion of the back side of each cell in the bifacial photovoltaic assembly that is not blocked by the support structure according to the position of the target photovoltaic array in the two-dimensional Cartesian coordinate system, the boundary of the support structure in the two-dimensional Cartesian coordinate system, and the irradiance received by each segment of the ground area; A fourth calculation unit, configured to calculate the direct radiation received by the back side of each cell in the bifacial photovoltaic module according to the arrangement position, installation parameters and current sun position vector of the target photovoltaic array; The fifth calculation unit is used to respectively calculate the sum of the sky scattered radiation, ground reflected radiation and direct radiation received by the back side of each cell in the bifacial photovoltaic module to obtain the back side radiation distribution of the bifacial photovoltaic module.

8. An electronic device, characterized in that: The method comprises at least one processor and a memory connected to the processor, wherein: The memory is used to store computer programs; The processor is used to execute the computer program so that the electronic device can implement the method for calculating the back side irradiance distribution of a bifacial photovoltaic module as described in any one of claims 1 to 6.

9. A computer program product, characterized in that The method comprises computer-readable instructions, and when the computer-readable instructions are executed on an electronic device, the electronic device implements the method for calculating the back side irradiance distribution of a bifacial photovoltaic module as claimed in any one of claims 1 to 6.

10. A computer storage medium, characterized in that: The storage medium carries one or more computer programs, and when the one or more computer programs are executed by an electronic device, the electronic device can implement the method for calculating the back side irradiance distribution of a bifacial photovoltaic module as described in any one of claims 1 to 6.

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