Dynamic impedance matching method and device for photovoltaic array

Abstract

The invention relates to the technical field of data processing, and discloses a dynamic impedance matching method and device for a photovoltaic array. The method comprises the steps that dynamic calculation processing is conducted on component power characteristic parameters and component impedance characteristic parameters through an incremental conductance method, impedance adjusting signals are obtained, and the impedance adjusting signals comprise adjusting step length parameters; interleaving parallel control processing is conducted on the impedance adjusting signal, a first control signal and a second control signal are obtained, and the phase difference between the first control signal and the second control signal is 180 degrees; three-point sampling comparison processing is carried out on the first control signal and the second control signal, an optimal power point signal is obtained, and the optimal power point signal is used for updating the impedance adjusting signal; and performing hierarchical transmission processing on the optimal power point signal to obtain photovoltaic array operation state data, and transmitting the photovoltaic array operation state data through carrier communication. According to the invention, the efficiency and accuracy of dynamic impedance matching of the photovoltaic array are improved.

Description

Technical Field

[0001] This application relates to the field of data processing, and in particular to a dynamic impedance matching method and device for a photovoltaic array. Background Art

[0002] With the rapid development of photovoltaic technology, photovoltaic arrays have become an important form of clean energy application. In order to improve the overall efficiency of photovoltaic systems, researchers and engineers have proposed various methods to optimize the operating efficiency of photovoltaic arrays. Among them, dynamic impedance matching technology, as an important means to improve the power output of photovoltaic modules, has received extensive attention. Current dynamic impedance matching methods usually rely on real-time acquisition and analysis of data such as the output power, input current, and voltage of photovoltaic modules, and adjust the working state of the modules through a control circuit, so as to compensate for the impedance differences between photovoltaic modules and achieve the purpose of optimizing the energy conversion efficiency. Existing technologies generally use methods such as synchronous potential acquisition, digital filtering, and characteristic analysis to obtain the power characteristics and impedance characteristic parameters of photovoltaic modules, and then adjust system parameters to improve the overall power generation efficiency.

[0003] However, the dynamic impedance matching methods in the existing technologies often have the following deficiencies: First, the existing multi-channel data acquisition schemes usually rely on relatively simple current-voltage sampling technologies, and do not fully consider the dynamic changes of each component in the photovoltaic array, resulting in poor data accuracy and real-time performance, and it is difficult to capture the change trend of the photovoltaic array in real time. Second, although the existing methods extract the characteristic parameters of photovoltaic modules through digital filtering and curve analysis, for a photovoltaic array with frequent and complex current-voltage changes, the parameter calculation process is still relatively rough, and it is difficult to accurately match the dynamic characteristics of the modules. In addition, the existing dynamic adjustment methods often fail to effectively consider the synergistic effect between components, resulting in unsatisfactory system adjustment effects when multiple photovoltaic modules work together, and the impedance adjustment process is relatively slow and inefficient. Summary of the Invention

[0004] This application provides a dynamic impedance matching method and device for a photovoltaic array, which are used to improve the efficiency and accuracy of dynamic impedance matching of the photovoltaic array.

[0005] In a first aspect, this application provides a dynamic impedance matching method for a photovoltaic array, and the dynamic impedance matching method for the photovoltaic array includes:

[0006] Perform multi-channel synchronous potential acquisition on the output ends of each photovoltaic module in the photovoltaic array to obtain first voltage data and first current data; the multi-channel synchronous potential acquisition performs data transmission through a master-slave communication architecture;

[0007] Perform digital filtering and curve analysis on the first voltage data and the first current data to obtain component power characteristic parameters and component impedance characteristic parameters. The component power characteristic parameters include the slope of the power-voltage curve;

[0008] Perform dynamic calculation on the component power characteristic parameters and the component impedance characteristic parameters by the conductance increment method to obtain an impedance adjustment signal. The impedance adjustment signal includes an adjustment step parameter;

[0009] Perform interleaved parallel control on the impedance adjustment signal to obtain a first control signal and a second control signal. The phase difference between the first control signal and the second control signal is 180 degrees;

[0010] Perform three-point sampling comparison on the first control signal and the second control signal to obtain an optimal power point signal. The optimal power point signal is used to update the impedance adjustment signal;

[0011] Perform hierarchical transmission on the optimal power point signal to obtain photovoltaic array operation state data. The photovoltaic array operation state data is transmitted through carrier communication.

[0012] In a second aspect, the present application provides a dynamic impedance matching device for a photovoltaic array. The dynamic impedance matching device for a photovoltaic array includes:

[0013] An acquisition module for performing multi-channel synchronous potential acquisition on the output ends of each photovoltaic component in the photovoltaic array to obtain first voltage data and first current data. The multi-channel synchronous potential acquisition performs data transmission through a master-slave communication architecture;

[0014] An analysis module for performing digital filtering and curve analysis on the first voltage data and the first current data to obtain component power characteristic parameters and component impedance characteristic parameters. The component power characteristic parameters include the slope of the power-voltage curve;

[0015] A calculation module for performing dynamic calculation on the component power characteristic parameters and the component impedance characteristic parameters by the conductance increment method to obtain an impedance adjustment signal. The impedance adjustment signal includes an adjustment step parameter;

[0016] A control module for performing interleaved parallel control on the impedance adjustment signal to obtain a first control signal and a second control signal. The phase difference between the first control signal and the second control signal is 180 degrees;

[0017] A comparison module for performing three-point sampling comparison on the first control signal and the second control signal to obtain an optimal power point signal. The optimal power point signal is used to update the impedance adjustment signal;

[0018] A transmission module, configured to perform hierarchical transmission processing on the optimal power point signal to obtain photovoltaic array operation status data, and the photovoltaic array operation status data is transmitted through carrier communication.

[0019] In the technical solution provided by this application, by performing multi-channel synchronous potential acquisition on the output ends of each photovoltaic module, the voltage and current data of each photovoltaic module can be accurately obtained, and through high-precision voltage division sampling and shunt monitoring sampling, the acquired data is ensured to have high accuracy and stability. Using the IEEE1588 clock synchronization technology enables precise synchronization of each data acquisition point, thus avoiding errors caused by data inconsistency. This provides a reliable data basis for subsequent power characteristic and impedance characteristic analysis. Secondly, the Butterworth digital filtering technology is used to filter the voltage and current data, which can effectively remove noise and high-frequency interference, ensure the purity of the data, and improve the calculation accuracy. Through the fitting process of the power-voltage curve, an accurate slope of the power-voltage curve can be obtained, providing a scientific basis for power maximization adjustment. In addition, the impedance characteristic analysis can understand the impedance behavior of the components in detail, providing key parameters for subsequent dynamic adjustment.

[0020] In terms of dynamic calculation, the introduction of the conductance increment method enables the system to accurately judge the adjustment direction based on the power conductance difference, and optimize the adjustment step size through the step size calculation method, ensuring the accuracy and stability of each adjustment. The generation of the adjustment signal can not only adjust the impedance in real time according to the current array state, but also effectively prevent the system instability caused by too fast or too slow adjustment. In terms of the generation and adjustment of the control signal, through the PWM waveform generation and phase shift processing, a 180-degree phase difference is formed between the first control signal and the second control signal in terms of phase, ensuring the complementarity of the signals. The insertion of the dead time further enhances the stability of the signal, avoids the electrical interference that may occur during the signal switching process, and improves the anti-interference ability and operation stability of the system.

[0021] Finally, through the three-point sampling comparison method, combined with the generation of the optimal power point signal and the carrier modulation technology, it is ensured that the system can obtain the optimal power output point in real time and accurately, and transmit the operation status data of the photovoltaic array to the remote monitoring system through carrier communication. This process not only improves the data transmission efficiency, but also ensures that the data will not be interfered during the transmission process, and has extremely high reliability and stability. Brief Description of the Drawings

[0022] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the accompanying drawings required for the description of the embodiments. Obviously, the accompanying drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0023] Figure 1 It is a schematic diagram of an embodiment of the dynamic impedance matching method for a photovoltaic array in an embodiment of the present application;

[0024] Figure 2 It is a schematic diagram of an embodiment of the dynamic impedance matching device for a photovoltaic array in an embodiment of the present application. Detailed implementation manners

[0025] The embodiments of the present application provide a dynamic impedance matching method and device for a photovoltaic array. The terms "first", "second", "third", "fourth", etc. (if any) in the specification, claims and above-mentioned accompanying drawings of the present application are used to distinguish similar objects, and do not have to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments described here can be implemented in an order other than that illustrated or described here. In addition, the terms "comprising" or "having" and any deformation thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units does not have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0026] For ease of understanding, the following describes the specific process of the embodiments of the present application. Please refer to Figure 1 An embodiment of the dynamic impedance matching method for a photovoltaic array in an embodiment of the present application includes:

[0027] Step S101: Perform multi-channel synchronous potential acquisition on the output ends of each photovoltaic component in the photovoltaic array to obtain first voltage data and first current data; the multi-channel synchronous potential acquisition performs data transmission through a master-slave communication architecture;

[0028] Step S102: Perform digital filtering and curve analysis processing on the first voltage data and the first current data to obtain component power characteristic parameters and component impedance characteristic parameters. The component power characteristic parameters include the slope of the power-voltage curve;

[0029] Step S103: Perform dynamic calculation processing on the component power characteristic parameters and the component impedance characteristic parameters by the conductance increment method to obtain an impedance adjustment signal. The impedance adjustment signal includes an adjustment step parameter;

[0030] Step S104: Perform interleaved parallel control processing on the impedance adjustment signal to obtain a first control signal and a second control signal, with a phase difference of 180 degrees between the first control signal and the second control signal;

[0031] Step S105: Perform three-point sampling comparison processing on the first control signal and the second control signal to obtain an optimal power point signal, which is used to update the impedance adjustment signal;

[0032] Step S106: Perform hierarchical transmission processing on the optimal power point signal to obtain photovoltaic array operation status data, which is transmitted through carrier communication.

[0033] It can be understood that the execution subject of this application can be a dynamic impedance matching device for a photovoltaic array, or a terminal or a server. Specifically, it is not limited here. This application embodiment is described by taking the server as the execution subject as an example.

[0034] Specifically, the voltage and current data of the photovoltaic modules are acquired in real time. To ensure the accuracy of data acquisition, high-precision voltage division sampling technology and current shunt monitors are used to sample the voltage and current signals of each photovoltaic module. Multi-channel synchronous potential acquisition realizes data transmission through a master-slave communication architecture. In this architecture, each photovoltaic module acts as a slave node to transmit data with the master control node. During data transmission, the voltage signal is accurately voltage-divided and sampled through a resistor voltage division network, while the current signal is monitored and sampled through a high-precision shunt monitor. The acquired voltage data and current data are respectively referred to as first voltage data and first current data, representing the actual electrical state of each module during operation. Next, digital filtering and curve analysis processing are performed on the acquired first voltage data and first current data. Since the signals in the photovoltaic array may contain high-frequency noise and interference, a Butterworth digital filter is used to denoise the voltage and current data to ensure the accuracy of subsequent analysis. The filtered data is used to calculate the power characteristics and impedance characteristic parameters of the photovoltaic modules. The most critical parameter in the power characteristics is the slope of the power-voltage curve, which reflects the impact of voltage change on power. Here, by fitting the filtered voltage and current data, the power-voltage curve of the module can be obtained, thereby determining the slope of the curve. In addition, the relationship between the voltage and current data can be further analyzed to obtain the impedance characteristics of the module. The impedance characteristics reflect the response ability of the photovoltaic module to current and voltage changes, and these parameters are the basis for realizing dynamic adjustment.

[0035] The conductance increment method is used to dynamically calculate the power characteristic parameters and impedance characteristic parameters of the components, and an impedance regulation signal is obtained. The conductance increment method is a method for adjusting the performance of a photovoltaic array by solving the rate of change between power and voltage. By analyzing the relationship between power and voltage, the conductance difference of power can be calculated, and the zero-point analysis of the conductance difference is used to judge the regulation direction of voltage or current. If the conductance difference is greater than zero, it means that the current voltage level is too high and the voltage needs to be reduced to optimize the power output; otherwise, the voltage needs to be increased. On this basis, the regulation step size, that is, the amplitude of each adjustment, also needs to be calculated according to the regulation direction to ensure the stable adjustment of the system. The calculation of the step size needs to consider the amplitude of the conductance change and the response characteristics of the components to avoid over-regulation leading to system instability. Then, the impedance regulation signal is processed by interleaved parallel control to obtain a first control signal and a second control signal. The phase difference between these two signals is 180 degrees, that is, these two signals are complementary. Interleaved parallel control is a commonly used regulation method, especially suitable for the case where multiple photovoltaic components are operating in parallel. In practical applications, multiple components in a photovoltaic array are often in parallel. At this time, the regulation signal needs to optimize the operating state of each component in a complementary manner to ensure that there is no conflict or mutual interference. By generating two control signals with a phase difference of 180 degrees, the photovoltaic array can achieve balanced adjustment among the components, thereby improving the overall efficiency.

[0036] The two control signals are processed by three-point sampling comparison to obtain the maximum power point signal. The purpose of this process is to find the best operating point, that is, the maximum power point, through accurate sampling. In operation, the pulse widths of the first control signal and the second control signal are sampled, and their center points are taken. Based on the center points, left and right offsets are made to obtain three-point sampling pulse width values. By collecting the power data at these three points and comparing them with the previous and subsequent sampling points, the maximum power point is selected as the maximum power point signal. This maximum power point signal directly affects the subsequent impedance regulation process, ensuring that the photovoltaic array operates at the best operating point. Finally, the maximum power point signal is processed by hierarchical transmission to obtain the operating state data of the photovoltaic array. These data include the power state information of each photovoltaic component, and the entire process is transmitted through carrier communication. Carrier modulation is a technology that maps a signal onto a high-frequency carrier for transmission, which can effectively improve the anti-interference ability of the signal and achieve long-distance transmission. The modulated signal is packed in a hierarchical manner and transmitted step by step to the monitoring system to ensure that the state data of the photovoltaic array can be transmitted to the remote system in real time for monitoring and management.

[0037] For example, assume that a photovoltaic array includes four photovoltaic modules. In actual operation, through multi-channel synchronous potential acquisition, the voltage of the first module is 40V and the current is 5A, the voltage of the second module is 42V and the current is 5.2A, the voltage of the third module is 39.5V and the current is 4.9A, and the voltage of the fourth module is 41V and the current is 5.1A. After Butterworth digital filtering, the filtered data is obtained, with voltages of 39.8V, 41V, 39.6V, 40.5V and currents of 5.05A, 5.15A, 4.95A, 5.05A. Next, calculate the slope of the power-voltage curve, obtain the power characteristic parameters, and further analyze the current-voltage relationship to calculate the impedance characteristic parameters. Through the conductance increment method, obtain the conductance difference, and judge the adjustment direction based on the difference. Assume the adjustment direction is to increase the voltage, and calculate the adjustment step size as 0.5V through the conductance increment method.

[0038] After interleaved parallel control, generate the first control signal and the second control signal, and ensure that their phase difference is 180 degrees. Through three-point sampling comparison, assume that the calculated three-point power data are 210W, 215W, and 212W respectively, select 215W as the maximum power, and obtain the optimal power point signal. Finally, the optimal power point signal is hierarchically transmitted through carrier modulation to ensure that the operation status data of the photovoltaic array are real-time fed back to the remote monitoring system. This process effectively optimizes the power output of the photovoltaic array, enabling it to continuously and stably operate in the optimal state.

[0039] In the embodiments of this application, through multi-channel synchronous potential acquisition of the output terminals of each photovoltaic module, the voltage and current data of each photovoltaic module can be accurately obtained, and through high-precision voltage division sampling and shunt monitoring sampling, it is ensured that the collected data has high accuracy and stability. Using the IEEE1588 clock synchronization technology enables precise synchronization of each data acquisition point, thereby avoiding errors caused by data inconsistency. This provides a reliable data basis for subsequent power characteristic and impedance characteristic analysis. Secondly, using Butterworth digital filtering technology to filter the voltage and current data can effectively remove noise and high-frequency interference, ensure the purity of the data, and improve the calculation accuracy. Through the fitting process of the power-voltage curve, an accurate power-voltage curve slope can be obtained, providing a scientific basis for power maximization adjustment. In addition, impedance characteristic analysis can understand the impedance behavior of the components in detail, providing key parameters for subsequent dynamic adjustment.

[0040] In terms of dynamic calculation, the introduction of the conductance increment method enables the system to accurately judge the adjustment direction based on the power conductance difference, and optimize the adjustment step size through the step size calculation method, ensuring the accuracy and stability of each adjustment. The generation of the adjustment signal can not only adjust the impedance in real time according to the current array state, but also effectively prevent the system instability caused by too fast or too slow adjustment. In terms of the generation and adjustment of the control signal, through the generation of the PWM waveform and phase shift processing, a 180-degree phase difference is formed between the first control signal and the second control signal in terms of phase, ensuring the complementarity of the signals. The insertion of the dead time further enhances the signal stability, avoids the possible electrical interference during the signal switching process, and improves the anti-interference ability and operation stability of the system.

[0041] Finally, through the three-point sampling comparison method, combined with the generation of the optimal power point signal and the carrier modulation technology, it is ensured that the system can obtain the best power output point in real time and accurately, and transmit the operation state data of the photovoltaic array to the remote monitoring system through carrier communication. This process not only improves the data transmission efficiency, but also ensures that the data will not be interfered during the transmission process, and has extremely high reliability and stability.

[0042] In a specific embodiment, the process of executing step S101 may specifically include the following steps:

[0043] (1) Perform high-precision voltage division sampling processing on the voltage signal at the output end of the photovoltaic module to obtain a voltage sampling signal. The high-precision voltage division sampling uses a resistor voltage division network, and perform shunt monitoring sampling processing on the current signal at the output end of the photovoltaic module to obtain a current sampling signal. The shunt monitoring sampling uses a high-precision shunt monitor;

[0044] (2) Perform IEEE1588 clock synchronization processing on the voltage sampling signal and the current sampling signal to obtain a synchronous timestamp signal. The time accuracy of the synchronous timestamp signal is better than 1 millisecond, and perform master-slave communication protocol encapsulation processing on the synchronous timestamp signal to obtain a synchronous data packet;

[0045] (3) Perform POWERBUS bus transmission processing on the synchronous data packet to obtain a first transmission data. The POWERBUS bus transmission uses a non-polar wiring method, and perform MODBUS protocol parsing processing on the first transmission data to obtain a second transmission data;

[0046] (4) Perform optoelectronic isolation processing on the second transmission data to obtain an isolated data signal. The isolation voltage of the isolated data signal is greater than 2.5 kV, and perform data synchronization and latching processing on the isolated data signal to obtain a latched data;

[0047] (5) Perform data verification processing on the latched data to obtain verified data. The data verification uses the cyclic redundancy check method, and perform data classification and storage processing on the verified data to obtain first voltage data and first current data;

[0048] (6) Perform data validity judgment processing on the first voltage data and the first current data to obtain a valid data flag. The valid data flag is used to indicate whether the data acquisition is successful, and perform data screening processing on the first voltage data and the first current data according to the valid data flag to obtain second voltage data and second current data.

[0049] Specifically, perform high-precision voltage division sampling on the output terminal voltage signal of the photovoltaic module to obtain a voltage sampling signal. This process uses a resistor voltage division network to achieve precise voltage signal division, so as to effectively capture the details of voltage changes. Similarly, for the current signal, sample the output terminal current of the photovoltaic module through a high-precision shunt monitor to obtain a current sampling signal. This method ensures the high precision of the voltage and current sampling signals for subsequent calculations and analyses. The collected voltage and current signals will undergo IEEE1588 clock synchronization processing to generate a synchronous timestamp signal. The IEEE1588 protocol is a standard clock synchronization protocol that can ensure the time alignment of multiple collected signals, and the time accuracy is better than 1 millisecond. In this way, the synchronization error caused by time delay between different components can be eliminated, ensuring that the data of each photovoltaic module is processed within the same time frame. The synchronous timestamp signal is further encapsulated by the master-slave communication protocol to generate a synchronous data packet, and the data is transmitted through the POWERBUS bus. The POWERBUS bus uses a non-polar wiring method to ensure stable data transmission under different connection conditions.

[0050] After data transmission, first obtain the second transmission data through MODBUS protocol parsing processing. The MODBUS protocol is a protocol commonly used for communication between industrial devices, which can ensure the integrity and reliability of data. To improve the security and reliability of data, perform optoelectronic isolation processing on the transmitted second data packet to ensure that the data will not be affected by electrical interference during transmission. The isolation voltage is greater than 2.5 kV to ensure that the isolation effect meets industrial standards. Next, the isolated data will undergo data synchronization and latching processing to ensure data synchronization and stably store it in the specified storage area. Through this synchronization and latching mechanism, data loss or misalignment can be effectively prevented. The latched data is subjected to data verification processing using the cyclic redundancy check (CRC) method. CRC is a commonly used error detection method, and by generating a check code, it can ensure that the data has not been tampered with or damaged during transmission.

[0051] After verifying the data, the data is classified and stored, and finally the first voltage data and the first current data are obtained. These data are important electrical data during the operation of the photovoltaic array, reflecting the working status of each component. To ensure the validity of the data, it is necessary to perform validity judgment processing on these data. The valid data judgment checks the collected data to determine whether there are acquisition errors or interferences. The valid data flag is used to indicate whether the data acquisition is successful. If the data is invalid or the acquisition fails, it will be marked as invalid data. Finally, based on the valid data flag, the first voltage data and the first current data are screened to obtain the second voltage data and the second current data. Through data screening, invalid or inaccurate sampling results are removed to ensure that the remaining data can represent the true electrical characteristics of the photovoltaic components during the analysis process. These screened data will be used as the basis for subsequent processing to calculate the power characteristics and impedance characteristic parameters of the photovoltaic components, thereby further adjusting the working status of the photovoltaic array.

[0052] In a specific embodiment, the process of executing step S102 may specifically include the following steps:

[0053] (1) Perform Butterworth digital filtering processing on the first voltage data and the first current data to obtain the filtered voltage data and the filtered current data, and perform power calculation processing on the filtered voltage data and the filtered current data to obtain the first power data;

[0054] (2) Perform curve fitting processing on the first power data and the filtered voltage data to obtain the slope of the power-voltage curve, and perform numerical analysis processing on the slope of the power-voltage curve to obtain the component power characteristic parameters;

[0055] (3) Perform impedance characteristic analysis processing on the filtered voltage data and the filtered current data to obtain the component impedance characteristic parameters, and the component impedance characteristic parameters are used for subsequent dynamic calculation processing.

[0056] Specifically, for the collected first voltage data and first current data, a Butterworth digital filter is applied for filtering. The Butterworth filter is a common low-pass filter that can effectively remove high-frequency noise in the signal while retaining the low-frequency part of the signal, which is crucial for the accurate analysis of voltage and current signals. Through this process, the filtered voltage data and current data are obtained. These filtered signals are smoother, reducing the interference of noise on subsequent analysis. Then, based on the filtered voltage and current data, power calculation is performed. Power is obtained by multiplying voltage and current, that is, power = voltage × current. Therefore, by performing a multiplication operation on the filtered voltage and current data, power data at each moment can be obtained, and these data reflect the output power of the photovoltaic module. Next, using the obtained first power data and the filtered voltage data, a power-voltage curve fitting is performed. The power-voltage curve reflects the change in power output of the photovoltaic module under different voltage conditions. By fitting, the slope of the curve can be obtained. The slope of the power-voltage curve is an important indicator for evaluating the performance of the photovoltaic module, which describes the rate of change of power output when the voltage changes. Through numerical analysis of the curve slope, the power characteristic parameters of the module are further obtained, and these parameters can help optimize the operating state of the photovoltaic array, ensure that the array operates near the maximum power point, and improve the overall power generation efficiency.

[0057] In addition, the filtered voltage and current data are also required for the impedance characteristic analysis of the module. Impedance is the ratio between current and voltage, reflecting the resistance of the module to the current. In practical applications, the impedance characteristic is one of the key factors for optimizing the operation of the photovoltaic array. By analyzing the filtered voltage and current data, the dynamic impedance characteristic of the module can be calculated. These impedance characteristic parameters provide the basic data for subsequent dynamic calculations and impedance regulation, and the operating state of the photovoltaic module can be adjusted according to needs during operation, so as to achieve the best power output.

[0058] For example, assume that at a certain moment, after Butterworth filtering, the obtained voltage data is 9.6V and the current data is 2.02A. The power obtained through power calculation is 9.6V × 2.02A = 19.39W. Then, based on the power-voltage relationship, curve fitting is performed, and the slope of the power-voltage curve is obtained as -0.15, indicating that as the voltage increases, the growth rate of power output gradually slows down. Finally, through impedance analysis, the dynamic impedance of the module is obtained as 4.76Ω. These data provide an in-depth understanding of the module performance and lay the foundation for subsequent dynamic impedance regulation and optimization work.

[0059] In a specific embodiment, the process of executing step S103 may specifically include the following steps:

[0060] (1) Calculate and process the conductance increment of the component power characteristic parameters and the component impedance characteristic parameters to obtain the power conductance difference, and perform zero-point analysis processing on the power conductance difference to obtain the adjustment direction data;

[0061] (2) Calculate and process the adjustment step of the adjustment direction data to obtain the adjustment step parameter, and perform range limit processing on the adjustment step parameter to obtain the impedance adjustment signal.

[0062] Specifically, the power conductance difference is calculated through the relationship between power and voltage. Conductance reflects the sensitivity of the power output of the photovoltaic module to voltage changes, and the power conductance difference calculates the change in power conductance between two moments. This difference can help determine the trend of power output with voltage changes, thereby determining the adjustment direction. For example, if the calculated power conductance difference at a certain moment is positive, it means that the power increases with the increase of voltage at this moment, and the voltage direction should be adjusted to reduce the power, so as to approach the maximum power point; on the contrary, if the power conductance difference is negative, it indicates that the voltage needs to be increased to improve the power output. In this way, the direction of adjusting the working state of the photovoltaic array can be determined. The adjustment direction data is used to calculate the adjustment step. The adjustment step is the amplitude of each adjustment, which determines the speed and amplitude of each adjustment. Usually, the size of the adjustment step is proportional to the size of the power conductance difference. The larger the conductance difference, the larger the step, thus accelerating the adjustment process; while the smaller the conductance difference, the smaller the step, to avoid system instability caused by over-adjustment. To ensure that the system does not over-adjust during the adjustment process, the adjustment step is restricted within a certain range. This range is usually set according to the working characteristics and safety range of the photovoltaic array. For example, if the maximum adjustment step set by the system is 0.005 and the minimum step is 0.001, when the calculated step exceeds the maximum value, the step will be limited to the maximum value; when the calculated step is less than the minimum value, it will be limited to the minimum step. Through such range limitation, it can be ensured that each impedance adjustment is neither too fast nor too slow, thus ensuring the stability and safety of the photovoltaic array.

[0063] In a specific embodiment, the process of executing step S104 may specifically include the following steps:

[0064] (1) Generate a PWM waveform for the impedance adjustment signal to obtain a reference PWM signal, and perform phase shift processing on the reference PWM signal to obtain a first control signal and a second control signal;

[0065] (2) Insert a dead time into the first control signal and the second control signal to obtain a dead time protection control signal.

[0066] Specifically, perform PWM (pulse width modulation) waveform generation processing on the impedance adjustment signal to obtain a reference PWM signal. The role of the PWM signal is to achieve precise current or voltage control by adjusting the pulse width, thereby regulating the output power of the photovoltaic array. The generation of the PWM waveform is based on the impedance adjustment signals obtained from conductance increment calculations. These signals represent the adjustment step size and direction. Through appropriate PWM waveform control, the required power adjustment can be precisely achieved. Perform phase shift processing on the reference PWM signal. The phase shift is to generate two control signals with a 180-degree phase difference: the first control signal and the second control signal. The key to this process is to modify the position of the time axis based on the reference PWM waveform, so that the phases of the two control signals are exactly opposite. This setting of the phase difference ensures that in actual control, the first control signal and the second control signal can work alternately, forming the effect of interleaved parallel control, and then effectively adjusting the impedance to maintain the stability and maximum power output of the photovoltaic array.

[0067] Assume that the period of the reference PWM signal is T, and offset by a time ΔT in the time domain, so that the period of the offset first control signal is exactly opposite to that of the second control signal. Assume that the PWM period of the first control signal is T1 and its phase shift amount is ΔT, then the PWM period of the second control signal is T2, where T2 = T1 + ΔT. Through such phase shift processing, ensure that the two control signals have a 180-degree phase difference during operation, optimize the adjustment response of the system, and avoid mutual interference between the two control signals. Further, in order to improve the stability of the system and avoid risks caused by too fast switching of the control signals, the first control signal and the second control signal also need to undergo dead time insertion processing. The dead time refers to adding a small delay when the two control signals are switched to ensure that they do not turn on simultaneously, preventing the two signals from driving simultaneously and causing short circuits or system instability. The insertion processing of the dead time ensures that the second control signal will start to act only after the first control signal is turned off, or the first control signal is activated after the second control signal is turned off, thus protecting the system from problems such as overcurrent.

[0068] For example, assume that in a control system of a photovoltaic array, the period of the reference PWM signal is 20 ms. After phase shift processing, the period of the first control signal is 20 ms, and the period of the second control signal is also 20 ms. However, due to the phase shift, the starting moment of the second control signal is 10 ms later than that of the first control signal. Then, insert a dead time of 2 ms. In this way, there will be a 2-ms delay during the switching process of the two control signals, ensuring that they will not switch on and off at the same moment, avoiding unnecessary current surges, and thus improving the safety and reliability of the system.

[0069] In a specific embodiment, the process of executing step S105 may specifically include the following steps:

[0070] (1) Perform center point extraction processing on the current pulse widths of the first control signal and the second control signal to obtain center pulse width values, and perform left and right offset processing based on the center pulse width values to obtain three-point sampled pulse width values;

[0071] (2) Perform power data acquisition processing on the three-point sampled pulse width values to obtain three-point power data, and perform maximum value judgment processing on the three-point power data to obtain an optimal power point signal.

[0072] Specifically, center point extraction is performed on the current pulse widths of the first control signal and the second control signal. By calculating the pulse width center of the two signals, an average pulse width value can be obtained. This average value serves as a reference, representing the overall pulse width situation of the system's current control signals. The determination of the center pulse width value provides a basis for subsequent offset calculations. Based on the center pulse width value, left and right offset processing is performed to generate three pulse width values. These pulse width values are the left offset, right offset, and the center pulse width itself of the center pulse width. The magnitude of the offset is usually determined according to the dynamic adjustment requirements of the system and can be increased or decreased as needed. Through such offsets, the system can perform power sampling at multiple pulse width values, thereby evaluating the power output effects corresponding to each pulse width value.

[0073] Then, power data acquisition is performed on these three different pulse width values. Each pulse width value corresponds to a specific power output. By measuring voltage and current data, the power at each pulse width point is calculated. These power data will provide a basis for determining the optimal power point. Through the acquired power data, the system can clarify the power output situations at different pulse width values, thereby providing necessary information for selecting the best operating state. Finally, the three-point power data are compared, and the maximum power value is selected to determine the optimal power point signal. This step automatically selects the best power output point by comparing the power outputs at different pulse widths. After determining the optimal power point, the system can update the impedance adjustment signal to ensure that the photovoltaic array always operates in the most efficient operating state, thereby achieving the maximum power output.

[0074] In a specific embodiment, the process of executing step S106 may specifically include the following steps:

[0075] (1) Perform carrier modulation processing on the optimal power point signal to obtain a modulation signal. The carrier modulation uses a frequency band of 3 - 4 MHz, and perform hierarchical packaging processing on the modulation signal to obtain a transmission data packet;

[0076] (2) Perform step-by-step transmission processing on the transmission data packet to obtain photovoltaic array operating state data, and the photovoltaic array operating state data includes power state information of each component.

[0077] Specifically, the maximum power point signal will undergo carrier modulation processing. The frequency band for carrier modulation is selected between 3 and 4 megahertz. This frequency band can not only ensure the stability of data transmission but also effectively avoid common interference frequencies, ensuring the reliability of the signal. Through carrier modulation, the maximum power point signal will be embedded into the carrier signal to form a modulated signal. The modulated signal can better adapt to the noise and attenuation problems that may be encountered during the transmission process, enhancing the data transmission quality. Then, the modulated signal will undergo hierarchical packetization processing to obtain transmission data packets. This process ensures that the signal can be segmented according to a certain structure during transmission, so that each data packet contains useful operating status information. The purpose of hierarchical packetization processing is to improve the transmission efficiency and accuracy of data and prepare for the subsequent step-by-step transmission process. During the packetization process, the signal will be divided into multiple data packets, and each data packet contains specific information, such as the power status of each photovoltaic module and related operating parameters. Through this structured method, the integrity and accuracy of the information can be ensured.

[0078] Finally, through step-by-step transmission processing of the transmission data packets, the complete operating status data of the photovoltaic array is finally obtained. Step-by-step transmission means that the packetized data packets are transmitted layer by layer in sequence and finally reach the management system or control terminal of the photovoltaic array. During this process, the data packets will be checked and forwarded at different nodes to ensure that each piece of data can successfully reach the target location. The operating status data of the photovoltaic array after transmission completion contains the power status information of each component, and this information is very important for subsequent dynamic adjustment and optimization. By continuously acquiring and analyzing this data, the control system can monitor the operating conditions of the photovoltaic array in real time and adjust the operating parameters according to the real-time data to ensure that the system is always in the optimal working state under different environmental conditions.

[0079] The dynamic impedance matching method of the photovoltaic array in the embodiment of the present application has been described above. Next, the dynamic impedance matching device of the photovoltaic array in the embodiment of the present application will be described. Please refer to Figure 2 , an embodiment of the dynamic impedance matching device of the photovoltaic array in the embodiment of the present application includes:

[0080] An acquisition module 201, configured to perform multi-channel synchronous potential acquisition on the output ends of each photovoltaic module in the photovoltaic array to obtain first voltage data and first current data; the multi-channel synchronous potential acquisition performs data transmission through a master-slave communication architecture;

[0081] An analysis module 202, configured to perform digital filtering and curve analysis processing on the first voltage data and the first current data to obtain component power characteristic parameters and component impedance characteristic parameters, where the component power characteristic parameters include the slope of the power-voltage curve;

[0082] A calculation module 203, configured to perform dynamic calculation processing on the component power characteristic parameters and the component impedance characteristic parameters by using the conductance increment method to obtain an impedance adjustment signal, where the impedance adjustment signal includes an adjustment step parameter;

[0083] A control module 204, configured to perform interleaved parallel control processing on the impedance adjustment signal to obtain a first control signal and a second control signal, where the phase difference between the first control signal and the second control signal is 180 degrees;

[0084] A comparison module 205, configured to perform three-point sampling comparison processing on the first control signal and the second control signal to obtain an optimal power point signal, where the optimal power point signal is used to update the impedance adjustment signal;

[0085] A transmission module 206, configured to perform hierarchical transmission processing on the optimal power point signal to obtain photovoltaic array operation state data, where the photovoltaic array operation state data is transmitted through carrier communication.

[0086] Through the collaborative cooperation of the above-mentioned various components, by performing multi-channel synchronous potential acquisition on the output ends of each photovoltaic component, the voltage and current data of each photovoltaic component can be accurately obtained, and through high-precision voltage division sampling and shunt monitoring sampling, it is ensured that the collected data has high accuracy and stability. Using the IEEE1588 clock synchronization technology enables precise synchronization of each data acquisition point, thereby avoiding errors caused by data inconsistency. This provides a reliable data basis for subsequent power characteristic and impedance characteristic analysis. Secondly, using Butterworth digital filtering technology to filter the voltage and current data can effectively remove noise and high-frequency interference, ensure the purity of the data, and improve the calculation accuracy. Through the fitting processing of the power-voltage curve, an accurate power-voltage curve slope can be obtained, providing a scientific basis for power maximization adjustment. In addition, impedance characteristic analysis can understand the impedance behavior of the components in detail, providing key parameters for subsequent dynamic adjustment.

[0087] In terms of dynamic calculation, the introduction of the conductance increment method enables the system to accurately judge the adjustment direction based on the power conductance difference, and optimize the adjustment step through the step calculation method, ensuring the accuracy and stability of each adjustment. The generation of the adjustment signal can not only adjust the impedance in real time according to the current array state, but also effectively prevent system instability caused by too fast or too slow adjustment. In the generation and adjustment of the control signal, through PWM waveform generation and phase shift processing, the first control signal and the second control signal form a 180-degree phase difference in phase, ensuring the complementarity of the signals. The insertion of the dead time further enhances the stability of the signal, avoids electrical interference that may occur during signal switching, and improves the anti-interference ability and operation stability of the system.

[0088] Finally, through the three-point sampling comparison method, combined with the generation of the optimal power point signal and carrier modulation technology, it is ensured that the system can obtain the best power output point in real time and accurately, and transmit the operation status data of the photovoltaic array to the remote monitoring system through carrier communication. This process not only improves the data transmission efficiency, but also ensures that the data will not be interfered during transmission, with extremely high reliability and stability.

[0089] As mentioned above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present application.

Claims

1. A dynamic impedance matching method for a photovoltaic array, characterized in that: The dynamic impedance matching method of the photovoltaic array comprises: Performing multi-channel synchronous potential acquisition on the output end of each photovoltaic module in the photovoltaic array to obtain first voltage data and first current data; the multi-channel synchronous potential acquisition is used to transmit data through a master-slave communication architecture; Performing digital filtering and curve analysis processing on the first voltage data and the first current data to obtain component power characteristic parameters and component impedance characteristic parameters, wherein the component power characteristic parameters include a power-voltage curve slope; Dynamically calculating and processing the component power characteristic parameter and the component impedance characteristic parameter by a conductance increment method to obtain an impedance adjustment signal, wherein the impedance adjustment signal includes an adjustment step parameter; Performing interleaved parallel control processing on the impedance adjustment signal to obtain a first control signal and a second control signal, wherein the phase difference between the first control signal and the second control signal is 180 degrees; Performing three-point sampling and comparison processing on the first control signal and the second control signal to obtain an optimal power point signal, wherein the optimal power point signal is used to update the impedance adjustment signal; The optimal power point signal is subjected to hierarchical transmission processing to obtain photovoltaic array operation status data, and the photovoltaic array operation status data is transmitted via carrier communication.

2. The dynamic impedance matching method of a photovoltaic array according to claim 1, characterized in that: The multi-channel synchronous potential acquisition is performed on the output end of each photovoltaic module in the photovoltaic array to obtain the first voltage data and the first current data; The multi-channel synchronous potential acquisition is performed through a master-slave communication architecture for data transmission, including: The voltage signal at the output end of the photovoltaic module is subjected to high-precision voltage division sampling processing to obtain a voltage sampling signal, wherein the high-precision voltage division sampling adopts a resistor voltage division network, and the current signal at the output end of the photovoltaic module is subjected to shunt monitoring sampling processing to obtain a current sampling signal, wherein the shunt monitoring sampling adopts a high-precision shunt monitor; Performing IEEE1588 clock synchronization processing on the voltage sampling signal and the current sampling signal to obtain a synchronization timestamp signal, wherein the time accuracy of the synchronization timestamp signal is better than 1 millisecond, and performing master-slave communication protocol encapsulation processing on the synchronization timestamp signal to obtain a synchronization data packet; Performing POWERBUS bus transmission processing on the synchronization data packet to obtain first transmission data, wherein the POWERBUS bus transmission adopts a non-polarity wiring mode, and performing MODBUS protocol parsing processing on the first transmission data to obtain second transmission data; Performing photoelectric isolation processing on the second transmission data to obtain an isolated data signal, wherein the isolation voltage of the isolated data signal is greater than 2.5 kilovolts, and performing data synchronization latch processing on the isolated data signal to obtain latched data; Performing data verification processing on the latched data to obtain verified data, wherein the data verification adopts a cyclic redundancy check method, and performing data classification and storage processing on the verified data to obtain the first voltage data and the first current data; The first voltage data and the first current data are subjected to data validity judgment processing to obtain a valid data flag, wherein the valid data flag is used to indicate whether data acquisition is successful, and the first voltage data and the first current data are subjected to data screening processing according to the valid data flag to obtain second voltage data and second current data.

3. The dynamic impedance matching method of a photovoltaic array according to claim 1, characterized in that: The digital filtering and curve analysis processing are performed on the first voltage data and the first current data to obtain component power characteristic parameters and component impedance characteristic parameters, wherein the component power characteristic parameters include a power-voltage curve slope, including: Performing Butterworth digital filtering on the first voltage data and the first current data to obtain filtered voltage data and filtered current data, and performing power calculation processing on the filtered voltage data and the filtered current data to obtain first power data; Performing curve fitting processing on the first power data and the filtered voltage data to obtain the slope of the power-voltage curve, and performing numerical analysis processing on the slope of the power-voltage curve to obtain the power characteristic parameter of the component; The impedance characteristic analysis process is performed on the filtered voltage data and the filtered current data to obtain the component impedance characteristic parameters, and the component impedance characteristic parameters are used for subsequent dynamic calculation processing.

4. The dynamic impedance matching method of a photovoltaic array according to claim 1, characterized in that: The method of dynamically calculating and processing the component power characteristic parameter and the component impedance characteristic parameter by the conductance increment method to obtain an impedance adjustment signal, wherein the impedance adjustment signal includes an adjustment step parameter, includes: Performing conductance increment calculation processing on the component power characteristic parameter and the component impedance characteristic parameter to obtain a power conductance difference, and performing zero point analysis processing on the power conductance difference to obtain adjustment direction data; The adjustment direction data is processed by step calculation to obtain the adjustment step parameter, and the adjustment step parameter is processed by range limitation to obtain the impedance adjustment signal.

5. The dynamic impedance matching method of a photovoltaic array according to claim 1, characterized in that: The step of performing interleaved parallel control processing on the impedance adjustment signal to obtain a first control signal and a second control signal, wherein the phase difference between the first control signal and the second control signal is 180 degrees, comprises: Performing PWM waveform generation processing on the impedance adjustment signal to obtain a reference PWM signal, and performing phase shift processing on the reference PWM signal to obtain the first control signal and the second control signal; Dead time insertion processing is performed on the first control signal and the second control signal to obtain a dead time protection control signal.

6. The dynamic impedance matching method of a photovoltaic array according to claim 1, characterized in that: The performing three-point sampling and comparison processing on the first control signal and the second control signal to obtain an optimal power point signal, wherein the optimal power point signal is used to update the impedance adjustment signal, comprises: Performing center point extraction processing on the current pulse widths of the first control signal and the second control signal to obtain a center pulse width value, and performing left and right offset processing according to the center pulse width value to obtain a three-point sampling pulse width value; Power data acquisition processing is performed on the three-point sampled pulse width values ​​to obtain three-point power data, and maximum value judgment processing is performed on the three-point power data to obtain the optimal power point signal.

7. The dynamic impedance matching method of a photovoltaic array according to claim 1, characterized in that: The step of performing hierarchical transmission processing on the optimal power point signal to obtain photovoltaic array operation status data, wherein the photovoltaic array operation status data is transmitted via carrier communication, comprises: Carrier modulation is performed on the optimal power point signal to obtain a modulated signal, wherein the carrier modulation adopts a 3-4 MHz frequency band, and the modulated signal is hierarchically packaged to obtain a transmission data packet; The transmission data packet is processed step by step to obtain the photovoltaic array operation status data, and the photovoltaic array operation status data includes power status information of each component.

8. A dynamic impedance matching device for a photovoltaic array, used to implement the dynamic impedance matching method for a photovoltaic array as claimed in any one of claims 1 to 7, characterized in that: The dynamic impedance matching device of the photovoltaic array comprises: A collection module is used to perform multi-channel synchronous potential collection on the output end of each photovoltaic module in the photovoltaic array to obtain first voltage data and first current data; the multi-channel synchronous potential collection is used to transmit data through a master-slave communication architecture; an analysis module, configured to perform digital filtering and curve analysis processing on the first voltage data and the first current data to obtain component power characteristic parameters and component impedance characteristic parameters, wherein the component power characteristic parameters include a power-voltage curve slope; A calculation module, used for dynamically calculating and processing the power characteristic parameter of the component and the impedance characteristic parameter of the component by a conductance increment method to obtain an impedance adjustment signal, wherein the impedance adjustment signal includes an adjustment step parameter; A control module, configured to perform interleaved parallel control processing on the impedance adjustment signal to obtain a first control signal and a second control signal, wherein the phase difference between the first control signal and the second control signal is 180 degrees; A comparison module, used for performing three-point sampling comparison processing on the first control signal and the second control signal to obtain an optimal power point signal, wherein the optimal power point signal is used to update the impedance adjustment signal; The transmission module is used to perform hierarchical transmission processing on the optimal power point signal to obtain photovoltaic array operation status data, and the photovoltaic array operation status data is transmitted through carrier communication.

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