Shadow compensation and power smoothing light storage control method, system, device and medium
By collecting real-time data on the irradiance of the photovoltaic array to calculate mismatch compensation parameters and equivalent current, and combining this with power smoothing parameters and current closed-loop control, the problems of component mismatch and grid-connected power fluctuation caused by local shading in the photovoltaic array were solved, thereby improving photovoltaic power generation and power quality.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ANHUI UNIVERSITY OF ARCHITECTURE
- Filing Date
- 2026-06-09
- Publication Date
- 2026-07-14
AI Technical Summary
Existing technologies cannot effectively solve the problems of component mismatch and grid-connected power fluctuation caused by local shading in photovoltaic arrays, nor can they simultaneously utilize energy storage units to smooth out random fluctuations in photovoltaic output and eliminate component mismatch caused by local shading.
By collecting the irradiance of the photovoltaic array in real time to calculate the mismatch compensation parameters, mismatch compensation and equivalent current calculation are performed. Combined with power smoothing parameters and current closed-loop control, the current is regulated by the command current of the energy storage unit to achieve shading compensation and power smoothing of the photovoltaic array.
It achieves mismatch compensation of photovoltaic modules and smooth output of grid-connected power, improves photovoltaic power generation and grid-connected power quality, optimizes the maximum power point tracking process, and reduces system complexity and cost.
Smart Images
Figure CN122394099A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of photovoltaic power generation and energy storage coordinated control technology, specifically a photovoltaic-energy storage control method, system, equipment and medium for shading compensation and power suppression. Background Technology
[0002] As an important component of renewable energy, photovoltaic power generation faces two major challenges in practical applications due to environmental factors:
[0003] First, there is the mismatch caused by localized shading. Affected by factors such as cloud movement, building obstruction, or dust accumulation, the intensity of sunlight received by the series-connected photovoltaic modules is inconsistent, resulting in a multi-peak characteristic in the array's output power. This not only significantly reduces the system's power generation efficiency but may also cause hot spot effects that damage the modules. Second, there is the volatility of output power. Random variations in sunlight intensity cause the photovoltaic output power to be intermittent and fluctuating. This unstable power injection can impact the power quality and stability of the power grid.
[0004] In existing technologies, to address the mismatch problem caused by local shading, micro-inverters or distributed maximum power point tracking (DMPPT) devices (such as power optimizers) are typically employed. For example, invention patent CN 121116006 A proposes a hybrid scanning and dynamic parameter adaptive MPPT control method and photovoltaic module, including real-time acquisition of the voltage and current of the PV module; dynamic step-size control based on a preset power gradient; analysis of power curve characteristics, multi-peak identification, and elimination of spurious peaks; acquisition of real-time temperature and calculation of temperature compensation; automatic correction of the voltage reference range based on the temperature coefficient; filtering of shading transient power change rate; determination and recording of an initial fixed threshold; and adjustment of DC... The DC converter duty cycle is adjusted and PWM is output to lock the global maximum power point.
[0005] While these solutions effectively mitigate mismatch, they cannot smooth out power oscillations caused by sudden changes in sunlight. To address power fluctuations, energy storage systems are typically configured on the grid-connected side, employing peak shaving and valley filling strategies to smooth out fluctuations. Although this architecture performs excellently in smoothing system power fluctuations, its electrical topology limitations prevent it from effectively addressing module mismatches within the photovoltaic array.
[0006] In summary, existing technologies typically treat mismatch compensation under localized shading and grid-connected power smoothing as two separate problems. Therefore, how to construct a photovoltaic-storage system architecture that can both utilize energy storage units to smooth random fluctuations in photovoltaic output and eliminate module mismatch caused by localized shading through flexible current regulation has become a pressing issue. Summary of the Invention
[0007] The technical problem to be solved by this invention is how to construct a photovoltaic-storage system control method that can both smooth the random fluctuations of photovoltaic output by utilizing energy storage units and eliminate component mismatch caused by local shading through flexible current regulation.
[0008] The present invention solves the above-mentioned technical problems through the following technical means: The light intensity of each photovoltaic module in the photovoltaic array of the photovoltaic energy storage system is collected in real time, and the mismatch compensation parameters of the photovoltaic array are calculated based on the light intensity. Mismatch compensation is performed on each photovoltaic row subarray in the photovoltaic array according to the mismatch compensation parameters, and the equivalent current of the photovoltaic-storage module in the photovoltaic-storage system after mismatch compensation is calculated. The output voltage of the photovoltaic row sub-array in the photovoltaic array is collected in real time. The equivalent power after mismatch compensation is calculated based on the output voltage and the equivalent current. The equivalent power is then filtered to obtain power smoothing parameters. Calculate the power smoothing current component and the equalization current component based on the power smoothing parameter and the mismatch compensation parameter, and generate the energy storage unit command current based on the power smoothing current component and the equalization current component. The photovoltaic sub-array is subjected to closed-loop current control based on the current command corresponding to the energy storage unit command current. The equivalent current after mismatch compensation is used as a feedback signal, and maximum power point tracking is performed based on the feedback signal and the voltage of the photovoltaic array after current closed-loop control.
[0009] Optionally, calculating the mismatch compensation parameters of the photovoltaic array based on the light intensity includes: Calculate the row theoretical short-circuit current of each row of photovoltaic subarrays in the photovoltaic array based on the light intensity; The theoretical row short-circuit current of each row of photovoltaic subarrays can be calculated using the following formula:
[0010] in, Indicates the first The theoretical short-circuit current of a row of photovoltaic sub-arrays. Indicates the first line, number List the light intensity of photovoltaic modules. This indicates the number of photovoltaic modules in each row of the photovoltaic subarray. This indicates the light intensity under preset standard test conditions. This indicates the short-circuit current under preset standard test conditions; The average value of the theoretical short-circuit current of the row is used as the mismatch compensation parameter of the photovoltaic array; The mismatch compensation parameters are calculated using the following formula:
[0011] in, Indicates the mismatch compensation parameter. This indicates the total number of rows in the photovoltaic subarray. Indicates the first The theoretical short-circuit current of a row of photovoltaic sub-arrays.
[0012] Optionally, the step of performing mismatch compensation on each photovoltaic row subarray in the photovoltaic array according to the mismatch compensation parameters, and calculating the equivalent current of the photovoltaic-storage module in the photovoltaic-storage system after mismatch compensation, includes: The equalization current component of each row of photovoltaic sub-arrays is calculated based on the mismatch compensation parameters. The equalization current component is calculated using the following formula:
[0013] in, Indicates the first Equal current components of row photovoltaic sub-arrays Indicates the mismatch compensation parameter. Indicates the first The theoretical short-circuit current of a row of photovoltaic sub-arrays; The photovoltaic row sub-array is mismatched and compensated according to the equal current component, and the output current of the photovoltaic row sub-array corresponding to the photovoltaic energy storage module is collected after the mismatch compensation. The equivalent current of the photovoltaic storage module in the photovoltaic storage system is calculated based on the output current and the equalization current component.
[0014] Optionally, the step of calculating the equivalent power after mismatch compensation based on the output voltage and the equivalent current, and filtering the equivalent power to obtain power smoothing parameters, includes: Calculate the equivalent power after mismatch compensation using the output voltage and the equivalent current; Calculate the average value of the equivalent power; The average value is subjected to a first-order low-pass filter to obtain the power smoothing parameter; The average value is subjected to a first-order low-pass filter using the following formula:
[0015] in, Indicates the power smoothing parameter. This represents the time constant of the preset first-order low-pass filter. This represents the predefined differential operator. This represents the average value of the equivalent power.
[0016] Optionally, calculating the power smoothing current component and the equalization current component based on the power smoothing parameters and the mismatch compensation parameters includes: Calculate the power deviation for each row between the power smoothing parameter and the equivalent power; Each row of power deviation is converted into a power smoothing current component; The equalization current component of each photovoltaic subarray is calculated based on the mismatch compensation parameters.
[0017] Optionally, the step of performing current closed-loop control on the photovoltaic subarray according to the current command corresponding to the energy storage unit command current includes: A current command is generated based on the total energy storage command current; The photovoltaic sub-array is controlled by a converter corresponding to each of the photovoltaic sub-arrays according to the current command.
[0018] Optionally, the step of performing maximum power point tracking based on the feedback signal and the voltage of the photovoltaic array after current closed-loop control includes: Call the maximum power point tracking module configured in the converter corresponding to each of the photovoltaic sub-arrays; The maximum power point tracking module is used to receive the feedback signal and collect the real-time port voltage of the photovoltaic array; Adjust the real-time port voltage, and perform maximum power point tracking based on the adjusted real-time port voltage and the feedback signal.
[0019] To address the aforementioned problems, this invention also proposes a light-storage control system with shadow compensation and power mitigation, the system comprising: The mismatch compensation parameter calculation module is used to collect the light intensity of each photovoltaic module in the photovoltaic array of the photovoltaic energy storage system in real time, and calculate the mismatch compensation parameters of the photovoltaic array based on the light intensity. The equivalent current calculation module is used to perform mismatch compensation on each photovoltaic row subarray in the photovoltaic array according to the mismatch compensation parameters, and to calculate the equivalent current of the photovoltaic-storage module in the photovoltaic-storage system after mismatch compensation. The power smoothing parameter calculation module is used to collect the output voltage of the photovoltaic row sub-array in the photovoltaic array in real time, calculate the equivalent power after mismatch compensation based on the output voltage and the equivalent current, and filter the equivalent power to obtain the power smoothing parameter. The energy storage unit command current generation module is used to calculate the power smoothing current component and the equalization current component based on the power smoothing parameters and the mismatch compensation parameters, and to generate the energy storage unit command current based on the power smoothing current component and the equalization current component. The energy storage control module is used to perform closed-loop current control on the photovoltaic sub-array according to the current command corresponding to the command current of the energy storage unit; The maximum power point tracking sampling point improvement module is used to use the equivalent current after mismatch compensation as a feedback signal, and to perform maximum power point tracking based on the feedback signal and the voltage of the photovoltaic array after current closed-loop control.
[0020] The present invention also provides a processing device, characterized in that it includes at least one processor and at least one memory communicatively connected to the processor, wherein: the memory stores program instructions executable by the processor, and the processor can execute the above-described method for controlling light storage with shading compensation and power suppression by calling the program instructions.
[0021] The present invention also provides a computer-readable storage medium, characterized in that the computer-readable storage medium stores computer instructions, the computer instructions causing the computer to perform the above-described method for controlling optical storage with shadow compensation and power shaving.
[0022] The advantages of this invention are: This invention controls the energy storage unit to absorb or release energy by controlling the total energy storage command current, thereby achieving the functions of mismatch compensation of photovoltaic modules and smooth output of grid-connected power. It simultaneously improves photovoltaic power generation and grid-connected power quality using the same set of energy storage units. The present invention has a maximum power point tracking (MPPT) module in the converter corresponding to the photovoltaic row array. The MPPT module uses the equivalent current of the photovoltaic-storage module after mismatch compensation as the optimization feedback signal, which can optimize the sampling path of the maximum power point tracking (MPPT) and effectively avoid the influence of the active adjustment action of the energy storage unit on the MPPT optimization process. It achieves accurate tracking of the maximum power point while smoothing power fluctuations. Attached Figure Description
[0023] Figure 1 This is a schematic flowchart of a light storage control method for shadow compensation and power suppression in one embodiment of the present invention; Figure 2 This is a schematic diagram of the architecture of a photovoltaic storage system according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the composition structure of a photovoltaic energy storage system in one embodiment of the present invention; Figure 4 This is a schematic diagram of the sampling point setup in one embodiment of the present invention; Figure 5 This is a schematic diagram of the circuit topology of a photovoltaic energy storage system in one embodiment of the present invention; Figure 6This is a functional block diagram of a photovoltaic energy storage control system with shadow compensation and power suppression provided in one embodiment of the present invention. Detailed Implementation
[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0025] Reference Figure 1 The diagram shown is a schematic flowchart of a shadow compensation and power stabilization optical storage control method according to an embodiment of the present invention. In this embodiment, the shadow compensation and power stabilization optical storage control method includes: S1. Real-time acquisition of the light intensity of each photovoltaic module in the photovoltaic array of the photovoltaic energy storage system, and calculation of the mismatch compensation parameters of the photovoltaic array based on the light intensity.
[0026] In this embodiment of the invention, the photovoltaic array is a TCT (Total CrossTied) photovoltaic array with n rows and m columns of fully cross-connected photovoltaic strings, which can be applied to, for example... Figure 2 In the illustrated photovoltaic-storage system architecture, for a fully cross-connected photovoltaic array, m photovoltaic modules within the same logical row are connected in parallel, and the logical rows are connected in series. All modules in the same row of different columns are connected in parallel, forming a "fully cross-connected" structure. Each row of photovoltaic subarrays is connected in parallel to an energy storage unit consisting of a bidirectional DC-DC (Bidirectional Direct Current to Direct Current Converter) converter and a battery, i.e., a photovoltaic-storage module. Specifically, the composition structure of the photovoltaic-storage system is as follows: Figure 3 As shown, by connecting the energy storage units in parallel to each row of photovoltaic subarrays, the number of power electronic devices is significantly reduced, thereby lowering the overall system cost and complexity.
[0027] In detail, the present invention installs a light sensor on each photovoltaic module in the photovoltaic array to form a distributed sensing network for real-time acquisition of the light intensity of the photovoltaic array. line, number The light intensity of the photovoltaic modules .
[0028] Specifically, the calculation of the mismatch compensation parameters of the photovoltaic array based on the light intensity includes: Calculate the row theoretical short-circuit current of each row of photovoltaic subarrays in the photovoltaic array based on the light intensity; The average value of the theoretical short-circuit current of the row is used as the mismatch compensation parameter of the photovoltaic array.
[0029] In this embodiment of the invention, the theoretical row short-circuit current of each row of photovoltaic sub-arrays is calculated using the following formula:
[0030] in, Indicates the first The theoretical short-circuit current of a row of photovoltaic sub-arrays. Indicates the first line, number List the light intensity of photovoltaic modules. This indicates the number of photovoltaic modules in each row of the photovoltaic subarray. This indicates the light intensity under preset standard test conditions. This indicates the short-circuit current under preset standard test conditions.
[0031] Furthermore, the mean of the theoretical short-circuit current of the n rows of photovoltaic sub-arrays is calculated as the mismatch compensation parameter. Specifically, the mismatch compensation parameter is calculated using the following formula:
[0032] in, Indicates the mismatch compensation parameter. This indicates the total number of rows in the photovoltaic subarray. Indicates the first The theoretical short-circuit current of a row of photovoltaic sub-arrays.
[0033] In this embodiment of the invention, the mismatch compensation parameter is the global reference equalization current of the photovoltaic array. Based on the mismatch compensation parameter, energy control of the energy storage unit can be performed, that is, mismatch compensation of the photovoltaic array can be performed.
[0034] S2. Perform mismatch compensation on each photovoltaic row subarray in the photovoltaic array according to the mismatch compensation parameters, and calculate the equivalent current of the photovoltaic-storage module in the photovoltaic-storage system after mismatch compensation.
[0035] In this embodiment of the invention, mismatch compensation for the photovoltaic array involves controlling the energy storage unit to discharge to release energy for photovoltaic sub-arrays with output current below the average value, and controlling the energy storage unit to charge to absorb energy for photovoltaic sub-arrays with output current above the average value.
[0036] Specifically, the step of performing mismatch compensation on each photovoltaic row subarray in the photovoltaic array according to the mismatch compensation parameters, and calculating the equivalent current of the photovoltaic-storage module in the photovoltaic-storage system after mismatch compensation, includes: The equalization current component of each row of photovoltaic sub-arrays is calculated based on the mismatch compensation parameters. The photovoltaic row sub-array is mismatched and compensated according to the equal current component, and the output current of the photovoltaic row sub-array corresponding to the photovoltaic energy storage module is collected after the mismatch compensation. The equivalent current of the photovoltaic storage module in the photovoltaic array is calculated based on the output current and the equalization current component.
[0037] In this embodiment of the invention, the equalization current component is calculated using the following formula:
[0038] in, Indicates the first Equal current components of row photovoltaic sub-arrays Indicates the mismatch compensation parameter. Indicates the first The theoretical short-circuit current of a row of photovoltaic sub-arrays.
[0039] In detail, mismatch compensation of the photovoltaic row array based on the equalization current component is performed on the equalization current component. When, control the corresponding energy storage unit to discharge to release energy; when When energy is released, the corresponding energy storage unit is charged to absorb energy. When releasing energy, the photovoltaic array outputs a positive power generation current, meaning the output current increases instantaneously; when absorbing energy, it charges the energy storage unit in the reverse direction, resulting in a decrease in the output current of the photovoltaic array.
[0040] One example is setting current sampling points on the photovoltaic module, such as... Figure 4 As shown, a set of sampling points (CT1) is set up to measure the output current of the photovoltaic array. The second group (sampling point CT2) is used to measure the port current of the photovoltaic array. .
[0041] In detail, the equivalent current of the photovoltaic row subarray in the photovoltaic module is calculated using the following formula:
[0042] in, Indicates the number of mismatch compensations after the first The equivalent current of the optical storage module. Indicates the first Equal current components of row photovoltaic sub-arrays Indicates the first Output current of the row photovoltaic sub-array.
[0043] In this embodiment of the invention, the output current of all photovoltaic subarrays can be balanced through mismatch compensation, thereby alleviating the power mismatch caused by shading.
[0044] S3. Real-time acquisition of the output voltage of the photovoltaic row sub-array in the photovoltaic array, calculation of the equivalent power after mismatch compensation based on the output voltage and the equivalent current, filtering of the equivalent power to obtain power smoothing parameters.
[0045] In this embodiment of the invention, two sets of sampling points can be set according to the above-described methods for collecting the output current of the photovoltaic array and measuring the port current of the photovoltaic array, for collecting the port voltage of the photovoltaic array. and the output voltage of each photovoltaic sub-array .
[0046] Specifically, the step of calculating the equivalent power after mismatch compensation based on the output voltage and the equivalent current, and then filtering the equivalent power to obtain power smoothing parameters includes: Multiply the output voltage by the equivalent current to obtain the equivalent power after mismatch compensation; Calculate the average value of the equivalent power; The average value is subjected to a first-order low-pass filter to obtain the power smoothing parameter.
[0047] In this embodiment of the invention, the output voltage of the photovoltaic subarray is multiplied by its equivalent current, and the product is used as the equivalent power of the photovoltaic energy storage module corresponding to the photovoltaic subarray. Then, the average value of all equivalent powers is calculated.
[0048] In detail, equivalent power It can be represented as:
[0049] Then the average value of the equivalent power Represented as:
[0050] Furthermore, the first-order low-pass filter is used to filter the average value of the equivalent power, thereby improving the accuracy of the generation of the total command current for subsequent energy storage.
[0051] In detail, the average value is subjected to a first-order low-pass filter using the following formula:
[0052] in, Indicates the power smoothing parameter. This represents the time constant of the preset first-order low-pass filter. This represents the predefined differential operator. This represents the average value of the equivalent power.
[0053] In this embodiment of the invention, the global smoothed power target value can be calculated by calculating the power smoothing parameters, which can provide a basis for subsequent power smoothing.
[0054] S4. Calculate the power smoothing current component and the equalization current component based on the power smoothing parameter and the mismatch compensation parameter, and generate the energy storage unit command current based on the power smoothing current component and the equalization current component.
[0055] In this embodiment of the invention, the energy storage unit command current is the current command of the photovoltaic energy storage module corresponding to each row of photovoltaic sub-arrays. The photovoltaic sub-arrays can be closed-loop controlled through the energy storage unit command current to release or absorb current to the corresponding photovoltaic sub-arrays.
[0056] Specifically, the step of calculating the power smoothing current component and the equalization current component based on the power smoothing parameters and the mismatch compensation parameters includes: Calculate the power deviation for each row between the power smoothing parameter and the equivalent power; Each row of power deviation is converted into a power smoothing current component; The equalization current component of each photovoltaic subarray is calculated based on the mismatch compensation parameters.
[0057] In this embodiment of the invention, the difference between the power smoothing parameter and the photovoltaic subarray of each row is calculated to obtain the power deviation of each row. The power deviation is then converted into a current component, resulting in the power smoothing current component for each photovoltaic subarray.
[0058]
[0059] in, Indicates power deviation. Indicates the power smoothing parameter. This represents the equivalent power.
[0060] Specifically, the power deviation of each row is converted into a power smoothing current component using the following formula:
[0061] in, Indicates the first Power smoothing of current components in row photovoltaic arrays. Indicates the first The power deviation between the actual power output of the row photovoltaic sub-array and the power smoothing parameters. Indicates the first Output voltage of the row photovoltaic sub-array.
[0062] In detail, the equalization current component of each photovoltaic row subarray can be calculated using the steps in S2 above. Equalize current components With power smoothing current component Add them together to obtain the command current for the energy storage unit. ,in, .
[0063] In this embodiment of the invention, the power smoothing current component can be used to control the energy storage unit to absorb or release high-frequency power fluctuation components, thereby making the external grid-connected power exhibit smooth characteristics; by superimposing the power smoothing current component with the equalization current component, the bidirectional DC-DC converter in the energy storage unit can be controlled to work, and mismatch compensation and power smoothing tasks can be completed at the same time.
[0064] S5. Perform current closed-loop control on the photovoltaic sub-array according to the current command corresponding to the energy storage unit command current.
[0065] In this embodiment of the invention, current closed-loop control involves releasing or absorbing current into the corresponding photovoltaic array, while maximum power point tracking involves finding the voltage and current that can output the maximum electrical energy in real time. By using the maximum power point, the optimal operating point of the photovoltaic array can be determined at all times to maximize power generation.
[0066] Specifically, the step of performing closed-loop current control on the photovoltaic subarray based on the current command corresponding to the energy storage unit command current includes: Generate a current command based on the energy storage unit's command current; The photovoltaic sub-array is controlled by a converter corresponding to each of the photovoltaic sub-arrays according to the current command.
[0067] In this embodiment of the invention, the current command is the current command of the bidirectional DC-DC converter. The total energy storage command current is added to each photovoltaic sub-array through the current command to control the photovoltaic array. The real-time port voltage of the photovoltaic array after current control is collected in real time using the above-mentioned sampling points.
[0068] S6. Using the equivalent current after mismatch compensation as a feedback signal, perform maximum power point tracking based on the feedback signal and the voltage of the photovoltaic array after current closed-loop control.
[0069] Preferably, the converter corresponding to the photovoltaic array is a DC-DC converter with a maximum power point tracking (MPPT) module, connected between the DC bus of the photovoltaic array and the load (or DC microgrid). This MPPT module is configured to receive the equivalent current from the photovoltaic-storage modules after mismatch compensation calculated by the central controller. The equivalent current is used as the feedback signal for optimization, and the real-time port voltage of the photovoltaic array is collected simultaneously. As the real-time port voltage (or the output voltage of each photovoltaic sub-array) The MPPT module executes the MPPT algorithm based on the feedback signal to achieve the maximum power output of the photovoltaic array.
[0070] In this embodiment of the invention, the step of performing maximum power point tracking based on the feedback signal and the voltage of the photovoltaic array after current closed-loop control includes: Call the maximum power point tracking module configured in the converter corresponding to each of the photovoltaic sub-arrays; The maximum power point tracking module is used to receive the feedback signal and collect the real-time port voltage of the photovoltaic array; Adjust the real-time port voltage, and perform maximum power point tracking based on the adjusted real-time port voltage and the feedback signal.
[0071] Specifically, the equivalent current and real-time port voltage within a preset MPPT algorithm cycle are sampled in real time to adjust the real-time port voltage. The real-time value of the feedback signal is collected, and the instantaneous power is calculated in real time. The direction of deviation of the current operating point from the maximum power point is determined by methods such as the incremental conductance method or the perturbation observation method. The duty cycle of the DC-DC converter is adjusted according to the deviation direction to change the real-time port voltage of the photovoltaic array. The real-time port voltage and equivalent current are sampled again, and the process is iterated until the real-time power no longer changes with the change of the real-time port voltage. The real-time port voltage and equivalent current corresponding to that point are the maximum power point. The maximum power point is continuously locked to achieve rapid tracking of sudden changes in illumination.
[0072] In detail, in this embodiment of the invention, for the light sensing system corresponding to the photovoltaic array, assuming the system includes N photovoltaic energy storage modules (photovoltaic row sub-arrays) connected in series, the port current of the photovoltaic array... for:
[0073] in, This represents the port current of the photovoltaic array. Indicates the first Output current of the row photovoltaic sub-array Indicates the command current of the energy storage unit. Indicates the number of mismatch compensations after the first The equivalent current of the optical storage module. Indicates the first Power smoothing current component of row photovoltaic sub-array.
[0074] Based on the steps described above for calculating the power smoothing current component, we can obtain:
[0075] The equivalent power after mismatch compensation
[0076] Substituting into the above equation and simplifying, we get:
[0077] Rearranging the terms in the above equation, we can obtain the output port voltage of each row of optical storage modules as follows:
[0078] From the above equation, it can be seen that the right side of the equation... and These are all global public variables, which at this point means the output voltage of each row of optical storage modules. Voltage balancing was achieved under a unified control strategy, namely:
[0079] in, Indicates the first The output voltage of each optical storage module , , These represent the first optical storage module, the second optical storage module, and the third optical storage module, respectively. The output voltage of each optical storage module This indicates the total number of optical storage modules. This represents the port current of the photovoltaic array. Indicates the number of mismatch compensations after the first The equivalent current of the optical storage module. Indicates the power smoothing parameter. This represents the equivalent power.
[0080] In this embodiment, the MPPT voltage sampling point is and The equivalent working principle is as follows: The physical characteristics of photovoltaic cells indicate that, under the same temperature, the maximum power point voltage of photovoltaic modules in the same batch will be... The voltage primarily depends on material properties and temperature, and is insensitive to changes in light intensity (i.e., the intensity of light mainly alters the current magnitude, having minimal impact on the voltage peak position). Therefore, it can be approximated that the optimal voltage point of each photovoltaic row subarray in the photovoltaic array is consistent.
[0081] In the formula: This is the voltage at the maximum power point of the first row of photovoltaic subarrays. For the first Voltage at the maximum power point of the row photovoltaic sub-array. This is the preset reference maximum power point voltage.
[0082] When the MPPT module uses the equivalent current after mismatch compensation and the output voltage of the photovoltaic storage module The maximum power point optimization control is performed using the feedback input so that when the photovoltaic row subarray reaches its maximum power point, it satisfies the following:
[0083] in, Indicates the first The output voltage of each optical storage module Indicates the first The voltage at the maximum power point of the row photovoltaic sub-array.
[0084] By combining the aforementioned automatic voltage equalization characteristics, the output voltages of all other unsampled photovoltaic subarrays are also forced to converge to the same voltage value. Furthermore, since the voltage at the maximum power point of each photovoltaic subarray is approximately equal, the output voltages of each row of the photovoltaic array at this time satisfy:
[0085] in, , , These represent the first optical storage module, the second optical storage module, and the third optical storage module, respectively. The output voltage of each optical storage module , , These represent the voltage at the maximum power point of the first row of photovoltaic subarrays, the voltage at the maximum power point of the second row of photovoltaic subarrays, and the voltage at the maximum power point of the third row of photovoltaic subarrays, respectively. The voltage at the maximum power point of the row photovoltaic sub-array.
[0086] At this time, the photovoltaic array port voltage for:
[0087] When the MPPT control module uses the equivalent current of a certain photovoltaic row subarray (e.g., row K) and the port voltage of the photovoltaic array When using the maximum power point optimization (MPPT) algorithm as input, the core objective is to find the extreme point where the derivative (gradient) of power with respect to voltage is zero. However, the port voltage of the photovoltaic array... Simply magnifying the voltage coordinate axis by a factor of N does not change the peak characteristics or optimization direction of the power curve. Therefore, sampling the port voltage of the photovoltaic array... It is also possible to find the maximum power point of the photovoltaic array. .
[0088] In this embodiment, in conjunction with the appendix Figure 5 The schematic diagram of the optical storage system circuit topology shown is compared with the traditional sampling point ( Explanation of the failure: The smoothing control strategy of this invention, in order to smooth photovoltaic power fluctuations, first calculates the equivalent power of the photovoltaic-storage module after mismatch compensation for each row. The average value of the equivalent power Through a time constant of A first-order low-pass filter is used to obtain power smoothing parameters. By controlling the charging and discharging of the energy storage unit, the output power of the photovoltaic array can be increased. Track this smoothing reference value .
[0089] Because the low-pass filter has a large time constant, within one sampling and operation cycle of the MPPT control module (typically on the order of milliseconds), the smoothed power reference value... Because its rate of change is much lower than the operation frequency of MPPT, it exhibits great inertia and can be approximated as a constant value.
[0090] In traditional MPPT control, the photovoltaic array port current is typically used as the control parameter. (Sampled by CT2) and port voltage As a feedback variable. In the system described in this invention, if the above sampling method is still used and the incremental conductance (INC) method is employed for maximum power point optimization, then, as mentioned above, the gradient of the observed current with respect to the voltage will be... It can be represented as:
[0091] Based on the optimization decision of the incremental conductance method ( We can obtain:
[0092] The above formula shows that, under the architecture and control strategy adopted in this invention, if the sampling points of the conventional MPPT are still used, according to the criterion rules of the INC algorithm, the MPPT algorithm will fail and will be unable to perform any optimization actions in response to environmental changes.
[0093] In summary, due to the intervention of the power smoothing control strategy, the rate of change of grid-connected power during the sampling and calculation cycle of the MPPT module is much lower than the sampling frequency of the MPPT, and can be approximated as a constant value. Therefore, the traditional method of sampling the photovoltaic array port current needs to be abandoned. As a feedback signal, the equivalent current of the optical-storage module after mismatch compensation is then collected. This is a necessary technical choice for the present invention to ensure stable operation under complex working conditions and to achieve global maximum power point tracking.
[0094] In this embodiment of the invention, the sampling path of maximum power point tracking (MPPT) can be optimized by using the MPPT module configured on the converter, effectively avoiding the impact of the active adjustment action of the energy storage unit on the MPPT optimization process, and realizing the smoothing of power fluctuations while accurately tracking the maximum power point.
[0095] like Figure 6 The diagram shown is a functional block diagram of a photovoltaic energy storage control system with shading compensation and power suppression provided in an embodiment of the present invention.
[0096] The shading compensation and power smoothing photovoltaic-storage control system 100 of this invention can be installed in a processing device. Depending on the functions implemented, the shading compensation and power smoothing photovoltaic-storage control system 100 may include a mismatch compensation parameter calculation module 101, an equivalent current calculation module 102, a power smoothing parameter calculation module 103, an energy storage unit command current generation module 104, an energy storage control module 105, and a maximum power point tracking sampling point improvement module 106. The module described in this invention can also be called a unit, which refers to a series of computer program segments that can be executed by the processor of an electronic device and can perform a fixed function, stored in the memory of the electronic device.
[0097] In this embodiment, the functions of each module / unit are as follows: The mismatch compensation parameter calculation module 101 is used to collect the light intensity of each photovoltaic module in the photovoltaic array of the photovoltaic energy storage system in real time, and calculate the mismatch compensation parameters of the photovoltaic array based on the light intensity. The equivalent current calculation module 102 is used to perform mismatch compensation on each photovoltaic row subarray in the photovoltaic array according to the mismatch compensation parameters, and to calculate the equivalent current of the photovoltaic energy storage module in the photovoltaic energy storage system after mismatch compensation. The power smoothing parameter calculation module 103 is used to collect the output voltage of the photovoltaic row sub-array in the photovoltaic array in real time, calculate the equivalent power after mismatch compensation based on the output voltage and the equivalent current, and filter the equivalent power to obtain the power smoothing parameter. The energy storage unit command current generation module 104 is used to calculate the power smoothing current component and the equalization current component according to the power smoothing parameters and the mismatch compensation parameters, and to generate the energy storage unit command current according to the power smoothing current component and the equalization current component. Energy storage control module 105 is used to perform current closed-loop control on the photovoltaic sub-array according to the current command corresponding to the energy storage unit command current; The maximum power point tracking sampling point improvement module 106 is used to take the equivalent current after mismatch compensation as a feedback signal, and perform maximum power point tracking based on the feedback signal and the voltage of the photovoltaic array after current closed-loop control.
[0098] As a further preferred technical solution, the mismatch compensation parameter calculation module 101 is specifically used for: Calculate the row theoretical short-circuit current of each row of photovoltaic subarrays in the photovoltaic array based on the light intensity; The theoretical row short-circuit current of each row of photovoltaic subarrays can be calculated using the following formula:
[0099] in, Indicates the first The theoretical short-circuit current of a row of photovoltaic sub-arrays. Indicates the first line, number List the light intensity of photovoltaic modules. This indicates the number of photovoltaic modules in each row of the photovoltaic subarray. This indicates the light intensity under preset standard test conditions. This indicates the short-circuit current under preset standard test conditions; The average value of the theoretical short-circuit current of the row is used as the mismatch compensation parameter of the photovoltaic array; The mismatch compensation parameters are calculated using the following formula:
[0100] in, Indicates the mismatch compensation parameter. This indicates the total number of rows in the photovoltaic subarray. Indicates the first The theoretical short-circuit current of a row of photovoltaic sub-arrays.
[0101] As a further preferred technical solution, the equivalent current calculation module 102 is specifically used for: The equalization current component of each row of photovoltaic sub-arrays is calculated based on the mismatch compensation parameters. The equalization current component is calculated using the following formula:
[0102] in, Indicates the first Equal current components of row photovoltaic sub-arrays Indicates the mismatch compensation parameter. Indicates the first The theoretical short-circuit current of a row of photovoltaic sub-arrays; The photovoltaic row sub-array is mismatched and compensated according to the equal current component, and the output current of the photovoltaic row sub-array corresponding to the photovoltaic energy storage module is collected after the mismatch compensation. The equivalent current of the photovoltaic storage module in the photovoltaic storage system is calculated based on the output current and the equalization current component.
[0103] As a further preferred technical solution, the power smoothing parameter calculation module 103 is specifically used for: Multiply the output voltage by the equivalent current to obtain the equivalent power after mismatch compensation; Calculate the average value of the equivalent power; The average value is subjected to a first-order low-pass filter to obtain the power smoothing parameter; The average value is subjected to a first-order low-pass filter using the following formula:
[0104] in, Indicates the power smoothing parameter. This represents the time constant of the preset first-order low-pass filter. This represents the predefined differential operator. This represents the average value of the equivalent power.
[0105] As a further preferred technical solution, the energy storage unit command current generation module 104 is specifically used for: Calculate the power deviation for each row between the power smoothing parameter and the equivalent power; Each row of power deviation is converted into a power smoothing current component; The equalization current component of each photovoltaic subarray is calculated based on the mismatch compensation parameters.
[0106] As a further preferred technical solution, the energy storage control module 105 is specifically used for: A current command is generated based on the total energy storage command current; The photovoltaic sub-array is controlled by a converter corresponding to each of the photovoltaic sub-arrays according to the current command.
[0107] As a further preferred technical solution, the maximum power point tracking sampling point improvement module 106 is specifically used for: Call the maximum power point tracking module configured in the converter corresponding to each of the photovoltaic sub-arrays; The maximum power point tracking module is used to receive the feedback signal and collect the real-time port voltage of the photovoltaic array; Adjust the real-time port voltage, and perform maximum power point tracking based on the adjusted real-time port voltage and the feedback signal.
[0108] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0109] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0110] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A method for controlling optical storage with shadow compensation and power mitigation, characterized in that, include: The light intensity of each photovoltaic module in the photovoltaic array of the photovoltaic energy storage system is collected in real time, and the mismatch compensation parameters of the photovoltaic array are calculated based on the light intensity. Mismatch compensation is performed on each photovoltaic row subarray in the photovoltaic array according to the mismatch compensation parameters, and the equivalent current of the photovoltaic-storage module in the photovoltaic-storage system after mismatch compensation is calculated. The output voltage of the photovoltaic row sub-array in the photovoltaic array is collected in real time. The equivalent power after mismatch compensation is calculated based on the output voltage and the equivalent current. The equivalent power is then filtered to obtain power smoothing parameters. Calculate the power smoothing current component and the equalization current component based on the power smoothing parameter and the mismatch compensation parameter, and generate the energy storage unit command current based on the power smoothing current component and the equalization current component. The photovoltaic sub-array is subjected to closed-loop current control based on the current command corresponding to the energy storage unit command current. The equivalent current after mismatch compensation is used as a feedback signal, and maximum power point tracking is performed based on the feedback signal and the voltage of the photovoltaic array after current closed-loop control.
2. The light storage control method for shadow compensation and power mitigation as described in claim 1, characterized in that, The calculation of the mismatch compensation parameters of the photovoltaic array based on the light intensity includes: Calculate the row theoretical short-circuit current of each row of photovoltaic subarrays in the photovoltaic array based on the light intensity; The theoretical row short-circuit current of each row of photovoltaic subarrays can be calculated using the following formula: in, Indicates the first The theoretical short-circuit current of a row of photovoltaic sub-arrays. Indicates the first line, number List the light intensity of photovoltaic modules. This indicates the number of photovoltaic modules in each row of the photovoltaic subarray. This indicates the light intensity under preset standard test conditions. This indicates the short-circuit current under preset standard test conditions; The average value of the theoretical short-circuit current of the row is used as the mismatch compensation parameter of the photovoltaic array; The mismatch compensation parameters are calculated using the following formula: in, Indicates the mismatch compensation parameter. This indicates the total number of rows in the photovoltaic subarray. Indicates the first The theoretical short-circuit current of a row of photovoltaic sub-arrays.
3. The light storage control method for shadow compensation and power mitigation as described in claim 1, characterized in that, The step of performing mismatch compensation on each photovoltaic row subarray in the photovoltaic array according to the mismatch compensation parameters, and calculating the equivalent current of the photovoltaic-storage module in the photovoltaic-storage system after mismatch compensation, includes: The equalization current component of each row of photovoltaic sub-arrays is calculated based on the mismatch compensation parameters. The equalization current component is calculated using the following formula: in, Indicates the first Equal current components of row photovoltaic sub-arrays Indicates the mismatch compensation parameter. Indicates the first The theoretical short-circuit current of a row of photovoltaic sub-arrays; The photovoltaic row sub-array is mismatched and compensated according to the equal current component, and the output current of the photovoltaic row sub-array corresponding to the photovoltaic energy storage module is collected after the mismatch compensation. The equivalent current of the photovoltaic storage module in the photovoltaic storage system is calculated based on the output current and the equalization current component.
4. The light storage control method for shadow compensation and power mitigation as described in claim 1, characterized in that, The process of calculating the equivalent power after mismatch compensation based on the output voltage and the equivalent current, and then filtering the equivalent power to obtain power smoothing parameters includes: Multiply the output voltage by the equivalent current to obtain the equivalent power after mismatch compensation; Calculate the average value of the equivalent power; The average value is subjected to a first-order low-pass filter to obtain the power smoothing parameter; The average value is subjected to a first-order low-pass filter using the following formula: in, Indicates the power smoothing parameter. This represents the time constant of the preset first-order low-pass filter. This represents the predefined differential operator. This represents the average value of the equivalent power.
5. The light storage control method for shadow compensation and power mitigation as described in claim 1, characterized in that, The calculation of the power smoothing current component and the equalization current component based on the power smoothing parameters and the mismatch compensation parameters includes: Calculate the power deviation for each row between the power smoothing parameter and the equivalent power; Each row of power deviation is converted into a power smoothing current component; The equalization current component of each photovoltaic subarray is calculated based on the mismatch compensation parameters.
6. The light storage control method for shadow compensation and power mitigation as described in claim 1, characterized in that, The step of performing closed-loop current control on the photovoltaic sub-array based on the current command corresponding to the energy storage unit command current includes: A current command is generated based on the total energy storage command current; The photovoltaic sub-array is controlled by a converter corresponding to each of the photovoltaic sub-arrays according to the current command.
7. The light storage control method for shadow compensation and power mitigation as described in claim 1, characterized in that, The step of performing maximum power point tracking based on the feedback signal and the voltage of the photovoltaic array after current closed-loop control includes: Call the maximum power point tracking module configured in the converter corresponding to each of the photovoltaic sub-arrays; The maximum power point tracking module is used to receive the feedback signal and collect the real-time port voltage of the photovoltaic array; Adjust the real-time port voltage, and perform maximum power point tracking based on the adjusted real-time port voltage and the feedback signal.
8. A light-storage control system for shadow compensation and power mitigation, characterized in that, include: The mismatch compensation parameter calculation module is used to collect the light intensity of each photovoltaic module in the photovoltaic array of the photovoltaic energy storage system in real time, and calculate the mismatch compensation parameters of the photovoltaic array based on the light intensity. The equivalent current calculation module is used to perform mismatch compensation on each photovoltaic row subarray in the photovoltaic array according to the mismatch compensation parameters, and to calculate the equivalent current of the photovoltaic-storage module in the photovoltaic-storage system after mismatch compensation. The power smoothing parameter calculation module is used to collect the output voltage of the photovoltaic row sub-array in the photovoltaic array in real time, calculate the equivalent power after mismatch compensation based on the output voltage and the equivalent current, and filter the equivalent power to obtain the power smoothing parameter. The energy storage unit command current generation module is used to calculate the power smoothing current component and the equalization current component based on the power smoothing parameters and the mismatch compensation parameters, and to generate the energy storage unit command current based on the power smoothing current component and the equalization current component. The energy storage control module is used to perform closed-loop current control on the photovoltaic sub-array according to the current command corresponding to the command current of the energy storage unit; The maximum power point tracking sampling point improvement module is used to use the equivalent current after mismatch compensation as a feedback signal, and to perform maximum power point tracking based on the feedback signal and the voltage of the photovoltaic array after current closed-loop control.
9. A processing device, characterized in that, It includes at least one processor and at least one memory communicatively connected to the processor, wherein: the memory stores program instructions executable by the processor, and the processor can execute the method as described in any one of claims 1-7 by invoking the program instructions.
10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that cause the computer to perform the method as described in any one of claims 1-7.