Photovoltaic cell iv testing method, apparatus, and iv testing device
By collecting photovoltaic cell IV test data at a fixed preset sampling rate, and performing downsampling and data filtering, combined with hysteresis compensation processing, the problem of data volume adaptability of IV testing equipment when the sampling rate is changed is solved, thus meeting various data volume requirements and improving data accuracy.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HANGZHOU MEIJIA INNOVATION TECHNOLOGY CO LTD
- Filing Date
- 2024-12-20
- Publication Date
- 2026-06-23
AI Technical Summary
When the sampling rate of existing IV detection equipment is changed, it is difficult to meet the different data volume requirements of different customers, resulting in the filter not conforming to the original design and being unable to adapt to the needs of various sampling data volumes.
Initial IV test data is collected by a fixed preset sampling rate, and target IV test data is obtained by downsampling and data filtering according to the target sampling parameters. Combined with hysteresis compensation processing, the performance parameters of the photovoltaic cell are obtained.
It enables the satisfaction of different data volume requirements without changing the sampling rate, improves data accuracy and applicability, and is suitable for a variety of testing scenarios.
Smart Images
Figure CN122268274A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of photovoltaic cell testing technology, and in particular to a photovoltaic cell IV testing method, apparatus and IV testing equipment. Background Technology
[0002] With the development of low-carbon economy and low-carbon technology, solar energy, as a clean and renewable energy source, has become a research hotspot in various countries. Photovoltaic cells, as photovoltaic devices that convert solar energy into electrical energy, have been widely used.
[0003] In photovoltaic cell applications, IV testing equipment is typically used to perform IV tests on photovoltaic cells to collect data. Then, based on the collected data, key performance parameters such as short-circuit current (Isc), open-circuit voltage (Voc), maximum power point current (Impp), and voltage (Vmpp) are extracted to evaluate photoelectric performance.
[0004] When conducting IV testing, different customers may require different amounts of data. Currently, scanning can be performed based on the user's desired sampling rate to obtain different data volumes. However, if the sampling rate of the IV testing equipment is changed, the cutoff frequency will change during the later design of filters, such as FIR and IIR filters, causing the filters to deviate from their original design intent. Therefore, current IV testing methods are difficult to meet the needs of scenarios requiring different data volumes. Summary of the Invention
[0005] This application provides a photovoltaic cell IV testing method, apparatus, and IV testing equipment to solve the aforementioned technical problems in the prior art.
[0006] According to a first aspect of this application, a photovoltaic cell IV testing method is provided, applied to an IV testing device, the method comprising:
[0007] Obtain the set target sampling parameters;
[0008] A scanning voltage is output to the photovoltaic cell to perform IV testing, and the initial IV test data obtained from the IV test is acquired at a preset sampling rate.
[0009] Target IV test data corresponding to the target sampling parameters are obtained from the initial IV test data using a downsampling method.
[0010] In some embodiments, the target sampling parameter includes the target sampling data volume; obtaining the target IV test data corresponding to the target sampling parameter from the initial IV test data using a downsampling method includes:
[0011] The initial IV test data is downsampled to obtain target IV test data with a data volume equal to the target sampled data volume.
[0012] In some embodiments, obtaining target IV test data corresponding to the target sampling parameters from the initial IV test data using a downsampling method includes:
[0013] The initial IV test data is downsampled using an equally spaced sampling method to obtain the target IV test data corresponding to the target sampling parameters.
[0014] In some embodiments, before obtaining the target IV test data corresponding to the target sampling parameter from the initial IV test data using a downsampling method, the method further includes:
[0015] The initial IV test data is then filtered.
[0016] Amplitude compensation is performed on the initial IV test data after data filtering to obtain the compensated initial IV test data.
[0017] The step of obtaining target IV test data corresponding to the target sampling parameters from the initial IV test data using a downsampling method includes:
[0018] Target IV test data corresponding to the target sampling parameters are obtained from the compensated initial IV test data using a downsampling method.
[0019] In some embodiments, the data filtering of the initial IV test data includes:
[0020] The initial IV test data were filtered using a 0-phase filter.
[0021] In some embodiments, the photovoltaic cell IV detection method further includes:
[0022] Obtain the set power control parameters;
[0023] The step of outputting a scanning voltage to the photovoltaic cell for IV testing includes:
[0024] According to the power control parameters, a scanning voltage is output to the photovoltaic cell at a preset sampling rate for IV testing.
[0025] According to a second aspect of this application, a method for testing the performance of photovoltaic cells is provided, applied to a host computer, comprising the following steps:
[0026] The target IV test data were obtained using the above-described photovoltaic cell IV test method;
[0027] Hysteresis compensation processing is performed on the target IV test data to obtain hysteresis-compensated IV test data;
[0028] The performance parameters of the photovoltaic cells were obtained from the IV test data after hysteresis compensation.
[0029] In some embodiments, the target IV test data includes forward scan IV test data and reverse scan IV test data; the step of performing hysteresis compensation processing on the target IV test data to obtain hysteresis-compensated IV test data includes:
[0030] A forward scan IV curve is generated based on the forward scan IV test data, and a reverse scan IV curve is generated based on the reverse scan IV test data;
[0031] Determine the corresponding forward scan current value and reverse scan current value in the forward scan IV curve and the reverse scan IV curve, respectively, for multiple target voltage values;
[0032] Based on the reverse scan current value and the forward scan current value at any target voltage value, the target current value corresponding to the target voltage value is determined to obtain the target current value corresponding to each target voltage value. The multiple target voltage values and the corresponding target current values are used as IV test data for hysteresis compensation processing.
[0033] According to a third aspect of this application, a photovoltaic cell IV testing apparatus is provided, the apparatus comprising:
[0034] The parameter acquisition module is used to acquire the set target sampling parameters;
[0035] The test module is used to output a scanning voltage to the photovoltaic cell for IV testing and to collect the initial IV test data obtained by the IV test at a preset sampling rate.
[0036] The downsampling module is used to obtain target IV test data corresponding to the target sampling parameters from the initial IV test data using a downsampling method.
[0037] According to a fourth aspect of this application, a performance testing device for photovoltaic cells is provided, comprising:
[0038] The parameter configuration module is used to obtain target IV test data using the above-mentioned photovoltaic cell IV test method;
[0039] The data processing module is used to perform hysteresis compensation processing on the target IV test data to obtain hysteresis-compensated IV test data; and to obtain the performance parameters of the photovoltaic cell based on the hysteresis-compensated IV test data.
[0040] According to a fifth aspect of this application, an IV testing device is provided, comprising: a processor and a memory storing computer program instructions; wherein the processor executes the computer program instructions to implement the steps of the above-described photovoltaic cell IV testing method.
[0041] According to a sixth aspect of this application, a computer-readable storage medium is provided, on which a computer program is stored, wherein the computer program, when executed by a processor, implements the steps of the above-described photovoltaic cell IV test method, or the computer program, when executed by a processor, implements the steps of the above-described photovoltaic cell performance testing method.
[0042] In summary, the photovoltaic cell IV testing method, photovoltaic cell performance testing method, apparatus, and IV testing equipment provided in this application have at least the following beneficial effects:
[0043] The initial IV test data is acquired by collecting IV test data at a fixed preset sampling rate. Then, according to the currently set target sampling parameters, the target IV test data corresponding to the target sampling parameters is obtained from the initial IV test data by downsampling. In this way, for different set target sampling parameters, the IV testing equipment internally samples data based on a fixed preset sampling rate and then downsamples to obtain the target test data corresponding to the target sampling parameters, so as to meet different needs. It can meet the needs of various sampling data volumes without changing the sampling rate inside the IV testing equipment, and has a wide range of applications. Attached Figure Description
[0044] To more clearly illustrate the technical solutions in the specific embodiments of this application, the accompanying drawings used in the specific embodiments will be briefly introduced below in conjunction with the accompanying drawings. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings or solutions can be obtained based on these drawings without creative effort.
[0045] Figure 1 This is a flowchart of a photovoltaic cell IV test method in one embodiment of this application;
[0046] Figure 2 This is a flowchart of a photovoltaic cell IV test method in another embodiment of this application;
[0047] Figure 3 This is a flowchart of a photovoltaic cell performance testing method in one embodiment of this application;
[0048] Figure 4 This is a schematic diagram of the forward and reverse IV curves;
[0049] Figure 5 This is a logic block diagram of a photovoltaic cell performance testing method in one embodiment of this application;
[0050] Figure 6 This is a schematic diagram showing the forward and reverse scan current values under a target voltage value in the forward and reverse scan IV curves.
[0051] Figure 7 This is a structural diagram of a photovoltaic cell IV test apparatus in one embodiment of this application;
[0052] Figure 8 This is a structural diagram of a photovoltaic cell performance testing device in one embodiment of this application;
[0053] Figure 9 This is a diagram illustrating the application environment for photovoltaic cell testing in one embodiment of this application;
[0054] Figure 10 This is a structural diagram of an IV detection device provided in one embodiment of this application. Detailed Implementation
[0055] To make the above and other features and advantages of this application clearer, the application is further described below with reference to the accompanying drawings. It should be understood that the specific embodiments given herein are for the purpose of explanation to those skilled in the art, and are exemplary only, not restrictive.
[0056] In the following description, numerous specific details are set forth to provide a thorough understanding of this application. However, it will be apparent to those skilled in the art that the specific details are not required to practice this application. In other instances, well-known steps or operations have not been described in detail to avoid obscuring this application.
[0057] The photovoltaic cell IV testing method provided in this application can be executed by the photovoltaic cell IV testing device provided in the embodiments of this application, which can be configured in IV testing equipment.
[0058] refer to Figure 1 The photovoltaic cell IV test method includes the following steps S110 to S150.
[0059] S110: Obtain the set target sampling parameters.
[0060] The target sampling parameter is a parameter that characterizes the amount of data to be sampled. For example, the target sampling parameter can be the target amount of data to be sampled, or it can include the target sampling rate and sampling duration, which determine the amount of data to be sampled.
[0061] Specifically, it can receive target sampling parameters set and sent by the user through other devices. For example, if the IV detection device is connected to a host computer, the user sets the target sampling parameters through the host computer, and the host computer sends the target sampling parameters to the IV detection device. It can be understood that for IV detection devices that include input devices, it can also receive target sampling parameters input by the user through the input device.
[0062] S130: Outputs a scanning voltage to the photovoltaic cell for IV testing, and collects the initial IV test data obtained from the IV test at a preset sampling rate.
[0063] The preset sampling rate is a fixed value set internally by the controller of the IV testing equipment, such as the MCU. After receiving the start scan signal, the controller of the IV testing equipment controls the voltage change of the connection points of the photovoltaic cell at the fixed preset sampling rate. Specifically, the power control frequency for controlling the voltage change can be equal to the preset sampling rate, thereby outputting a scan voltage to the photovoltaic cell based on the preset sampling rate for IV testing. During the scan, sampling is performed according to the preset sampling rate to obtain initial IV test data.
[0064] Specifically, IV testing includes testing in the first quadrant, where the photovoltaic cell acts as the power source. The first quadrant testing comprises two processes: forward IV scanning and reverse IV scanning. During forward IV scanning, the scanning voltage is sequentially increased based on a preset sampling rate for forward scanning. During reverse IV scanning, the scanning voltage is sequentially decreased based on a preset sampling rate for reverse scanning. During both forward and reverse scanning processes, sampling is performed at the preset sampling rate to obtain initial IV test data for both the forward and reverse scanning tests. IV testing also includes testing in the second, third, and fourth quadrants, where the photovoltaic cell acts as the load. Similar to the first quadrant, the scanning voltage is also measured at a preset sampling rate.
[0065] S150: Obtain the target IV test data corresponding to the target sampling parameters from the initial IV test data using a downsampling method.
[0066] The amount of data sampled based on the preset sampling rate is greater than the amount of data corresponding to the target sampling parameters. Specifically, the initial IV test data is downsampled according to the target sampling parameters, and the amount of the target IV test data corresponds to the target sampling parameters, thus obtaining the amount of data required by the user.
[0067] The aforementioned photovoltaic cell IV testing method acquires initial IV test data at a fixed preset sampling rate. Then, based on the currently set target sampling parameters, it obtains target IV test data corresponding to the target sampling parameters from the initial IV test data through downsampling. Thus, for different set target sampling parameters, the IV testing equipment internally samples and downsamples data based on a fixed preset sampling rate to obtain target test data corresponding to the target sampling parameters, meeting different needs. It does not require changing the sampling rate within the IV testing equipment to meet the needs of various sampling data volumes, and has a wide range of applications.
[0068] In some embodiments, the preset sampling rate is the maximum sampling rate that the IV detection device can set. Specifically, the preset sampling rate is related to the performance of the ADC (analog-to-digital converter) and MCU in the IV detection device for voltage and current sampling. If it is too high, the calculation time will be long; if it is too low, it will not meet the user's needs. It can be set to an acceptable maximum sampling rate according to the performance.
[0069] For photovoltaic cells with a large capacitance effect, large voltage changes can cause significant circuit oscillations, leading to inaccurate data acquisition. Therefore, by using a configurable maximum sampling rate, a higher sampling rate and corresponding power supply control frequency can reduce output variations, effectively minimizing oscillations on capacitor-like circuits and resulting in more accurate data acquisition.
[0070] In some embodiments, the target sampling parameter includes the target sampling data volume. Specifically, step S150 includes: downsampling the initial IV test data to obtain target IV test data with a data volume equal to the target sampling data volume.
[0071] By downsampling the initial IV test data, the amount of data in the target IV test data is equal to the target sampled data amount, thus achieving the set data amount requirement. For example, if the user sets the target sampled data amount to 200 data points, then 200 data points will be extracted from the initial IV test data in the forward scan IV test, and 200 data points will also be extracted from the initial IV test data in the reverse scan IV test.
[0072] In some embodiments, step S150 includes: downsampling the initial IV test data using an equally spaced sampling method to obtain target IV test data corresponding to the target sampling parameters.
[0073] By employing an equally spaced sampling method to downsample the initial IV test data, the sampling becomes more uniform. Specifically, the initial IV test data is downsampled using an equally spaced sampling method to obtain target IV test data with a data volume equal to the target sampled data volume.
[0074] In some embodiments, reference Figure 2 After step S130 and before step S150, steps S141 and S142 are also included.
[0075] S141: Perform data filtering on the initial IV test data.
[0076] Specifically, a filter is used to filter the initial IV test data. By filtering the data, interference noise can be removed, thereby improving the accuracy of the data; and since the preset sampling rate is a fixed value and does not change, the cutoff frequency of the filter used to filter the initial IV test data sampled based on the preset sampling rate is fixed and does not need to be changed.
[0077] S142: Perform amplitude compensation on the initial IV test data after data filtering to obtain the compensated initial IV test data.
[0078] Filters used for data filtering typically scale the waveform, and this scaling is frequency-dependent. By performing amplitude compensation after data filtering, the amplitude distortion introduced by the filtering process can be eliminated, restoring the amplitude characteristics before filtering and improving data accuracy.
[0079] Correspondingly, step S150 includes step S151: obtaining target IV test data with corresponding target sampling parameters from the compensated initial IV test data using a downsampling method.
[0080] By filtering and compensating the collected initial IV test data, the obtained data is more accurate. Therefore, downsampling the compensated initial IV test data yields more accurate target IV test data. Specifically, step S151 can involve downsampling the compensated initial IV test data using an equally spaced sampling method to obtain target IV test data corresponding to the target sampling parameters. Further, downsampling the compensated initial IV test data using an equally spaced sampling method yields target IV test data with a data volume equal to the target sampling data volume.
[0081] In some embodiments, step S141 includes: performing data filtering on the initial IV test data using a 0-phase filter.
[0082] By using a 0-phase filter, phase delay can be eliminated, data distortion can be avoided, and data accuracy can be improved, thereby improving the accuracy of IV testing.
[0083] In some embodiments, the above-described photovoltaic cell IV test method further includes: acquiring set power control parameters. These power control parameters include a scan voltage range and a scan time. Specifically, power control parameters set and sent by a user through other devices, such as a host computer, can be received.
[0084] Specifically, step S130, which involves outputting a scanning voltage to the photovoltaic cell for IV testing, includes: outputting a scanning voltage to the photovoltaic cell at a preset sampling rate according to the power supply control parameters, ensuring that the scanning voltage is within the scanning voltage range and the scanning duration reaches the corresponding scanning time. This allows for accurate control of the photovoltaic cell scanning.
[0085] This application also provides a method for testing the performance of photovoltaic cells, which can be executed by the photovoltaic cell performance testing device provided in the embodiments of this application. This device can be configured on a host computer.
[0086] refer to Figure 3 The performance testing method for photovoltaic cells includes the following steps S310 to S350.
[0087] S310: Obtain target IV test data using photovoltaic cell IV testing methods.
[0088] Specifically, the host computer can send the set target sampling parameters to the IV detection device, and the target IV test data can be obtained by executing the photovoltaic cell IV test method in the above embodiments through the IV detection device and then sent to the host computer.
[0089] S330: Perform hysteresis compensation processing on the target IV test data to obtain hysteresis-compensated IV test data.
[0090] Photovoltaic cells have internal capacitance, which often leads to inconsistencies in the IV curves obtained during forward and reverse scanning during IV testing, causing a hysteresis effect, for example... Figure 4 As shown, during forward scanning, the scanning voltage increases from 0 to the open-circuit voltage Voc. Based on the voltage value at the scanning point and the sampled current value, a forward scan IV curve representing the voltage-current relationship from the short-circuit current Isc to the open-circuit voltage Voc is generated, as shown below. Figure 4 The red curve represents the reverse scan. During reverse scanning, the scan voltage decreases from the open-circuit voltage Voc to 0. Based on the voltage value at the scan point and the sampled current value, a reverse scan IV curve is generated, representing the voltage-current relationship between the open-circuit voltage Voc and the short-circuit current Isc, as shown below. Figure 4 The blue curve represents the data error caused by hysteresis, which is compensated for through hysteresis compensation.
[0091] S350: Obtain the performance parameters of the photovoltaic cell based on the IV test data with hysteresis compensation.
[0092] Performance parameters are obtained by analyzing the IV test data. Specifically, a standard IV curve can be generated from the hysteresis-compensated IV test data as the true IV characteristic curve of the photovoltaic cell without the influence of capacitance. Performance parameters are then obtained based on the standard IV curve. These performance parameters include short-circuit current Isc, open-circuit voltage Voc, maximum power point MPP, fill factor FF, and other parameters.
[0093] Specifically, the standard IV curve of a photovoltaic cell can be determined based on the IV test data after hysteresis compensation, for example... Figure 4As shown in the green curve, the performance parameters of photovoltaic cells are extracted based on the standard curve, such as the values of short-circuit current Isc and open-circuit voltage Voc based on the standard IV curve.
[0094] The performance testing method for photovoltaic cells described above, by using the target IV test data obtained from the aforementioned photovoltaic cell IV test method, can flexibly extract the performance parameters of photovoltaic cells based on the required amount of target IV test data, and can also be applied to different testing scenarios.
[0095] In some embodiments, a filtering step is included before step S330: filtering the target IV test data. Noise is removed by filtering, further improving data accuracy.
[0096] In some embodiments, a calibration step is included before step S330: calibrating the target IV test data according to a selected correction standard.
[0097] The correction standard can be selected by the user. Specifically, the correction standard can be the standard corresponding to the test illumination and ambient temperature correction method in the photovoltaic industry, such as IEC60891, IEC60891A, Simple, etc. By calibrating the target IV test data, the influence of the test environment, such as illumination and temperature, on the measurement data is corrected, thereby improving the accuracy of the data.
[0098] Specifically, the calibration step can be performed after the filtering step, that is, calibrating the filtered target IV test data. For example... Figure 5 As shown, after receiving the raw data (target IV test data) sent by the IV detection device, the host computer filters the target IV test data using a filter and calibrates the filtered target IV test data according to the selected correction standard (STC calibration). Next, hysteresis compensation processing is performed on the calibrated target IV test data to obtain hysteresis-compensated IV test data. Finally, parameter calculations are performed based on the hysteresis-compensated IV test data to obtain the performance parameters of the photovoltaic cell. It can be understood that for cases where the forward and reverse scan IV curves highly overlap, hysteresis compensation processing can be omitted, and parameter calculations can be performed directly based on the calibrated target IV test data.
[0099] In some embodiments, the target IV test data includes forward scan IV test data and reverse scan IV test data. The forward scan IV test data is the target IV test data corresponding to the forward scan IV test, and the reverse scan IV test data is the target IV test data corresponding to the reverse scan IV test. Specifically, step S330 includes steps (a1) to (a3).
[0100] Step (a1): Generate the forward scan IV curve based on the forward scan IV test data, and generate the reverse scan IV curve based on the reverse scan IV test data.
[0101] Specifically, the forward scan IV test data includes the scanning voltage value and the corresponding sampled current value at each scanning point during the forward scan, and the reverse scan IV test data includes the scanning voltage value and the corresponding sampled current value at each scanning point during the reverse scan. The corresponding forward scan IV curve / reverse scan IV curve is generated based on multiple sets of scanning voltage values and corresponding current values.
[0102] Step (a2): Determine the corresponding forward and reverse current values for multiple target voltage values in the forward and reverse IV curves, respectively.
[0103] The target voltage value is a voltage value selected within the voltage range of the forward and reverse scan IV curves. Specifically, multiple voltage values can be randomly selected from the voltage values corresponding to the forward / reverse scan IV curves as target voltage values. The selected voltage values can be scan voltage values or not. Specifically, the forward scan current value at each target voltage value is obtained by determining the current value corresponding to the target voltage value in the forward scan IV curve, and the reverse scan current value at each target voltage value is obtained by determining the current value corresponding to the target voltage value in the reverse scan IV curve.
[0104] Step (a3): Based on the reverse sweep current value and forward sweep current value under any target voltage value, determine the target current value corresponding to the target voltage value, so as to obtain the target current value corresponding to each target voltage value. Use multiple target voltage values and corresponding target current values as IV test data for hysteresis compensation processing.
[0105] Specifically, a current value is calculated based on the reverse and forward scan current values at a target voltage value, and this current value is used as the target current value corresponding to that target voltage value. The target current value is calculated for all target voltage values to obtain the target current value corresponding to each target voltage value. The IV test data with hysteresis compensation processing includes each target voltage value and its corresponding target current value.
[0106] By combining the forward and reverse scan current values corresponding to the target voltage value in the forward and reverse scan IV curves, the target current value is determined, thus achieving hysteresis compensation. The resulting hysteresis-compensated IV test data can accurately reflect the characteristics of photovoltaic cells, thereby accurately extracting performance parameters.
[0107] In some embodiments, step (a3) involves determining the target current value corresponding to the target voltage value based on the reverse sweep current value and the forward sweep current value at any target voltage value, so as to obtain the target current value corresponding to each target voltage value. This step includes steps (a31) to (a33).
[0108] Step (a31): Calculate the difference between the reverse sweep current value and the forward sweep current value under the target voltage. The difference is the sum of the first difference part and the second difference part. The first difference part is the difference between the forward sweep current value and the target current value, and the second difference part is the difference between the reverse sweep current value and the target current value.
[0109] The target current value is the value between the forward scan current value and the reverse scan current value. Specifically, the difference, the first difference portion, and the second difference portion all represent the absolute value of the data. For example, the difference is equal to the absolute value of the difference between the reverse scan voltage value and the forward scan voltage value; the first difference portion is the absolute value of the difference between the forward scan current value and the target current value; and the second difference portion is the absolute value of the difference between the reverse scan current value and the target current value. Figure 6 For example, I1, I2, and I0 are the vertical coordinate values under the same horizontal axis (voltage value) in the IV curve. I2 is greater than I1. I0 is the target current value to be obtained. I1 is the forward scan current value. I2 is the reverse scan current value. I2-I1=a1+a2, where a1=I0-I1, which is the first difference part, and a2=I2-I0, which is the second difference part.
[0110] Step (a32): Calculate the ratio of the forward sweep current value to the reverse sweep current value under the target voltage. This ratio is used as the ratio of the corresponding first difference part and the second difference part.
[0111] The basic form of the capacitor charging and discharging formula is: I(t) = C * dV(t) / dt; where I(t) represents the current at time t, C represents the capacitance, and dV(t) / dt represents the rate of change of voltage. Current ratio calculations are performed for the same voltage value:
[0112]
[0113] The current ratio is the ratio, which is used as the ratio of the difference between the forward scan current value and the reverse scan current value and the target current value.
[0114] For example, Figure 6 In this context, the ratio of the forward scan current value to the reverse scan current value is equal to I1 / I2, and a1 / a2 = I1 / I2. It can be understood that in other embodiments, the ratio can also be obtained by calculating I2 / I1, where a2 / a1 = I2 / I1.
[0115] Step (a33): Calculate the target current value corresponding to the target voltage value based on the forward scan current value / reverse scan current value, the ratio and the difference under the target voltage.
[0116] Specifically, the target current value can be calculated based on the forward scan current value, ratio, and difference, or it can be calculated based on the reverse scan current value, ratio, and difference.
[0117] By using the reverse sweep current value, forward sweep current value, and their ratio and difference under the same target voltage value, the target current value is located between the corresponding forward sweep current value and reverse sweep current value. Thus, the target IV curve determined based on each target voltage value and target current value is located between the forward sweep IV curve and the reverse sweep IV curve, which can better perform hysteresis compensation and extract more accurate performance parameters.
[0118] Specifically, step (a33) includes calculating the target current value corresponding to the target voltage value using either formula (1) or formula (2):
[0119]
[0120]
[0121] Where I0 is the target current value corresponding to the target voltage, I1 is the forward scan current value under the target voltage, I2 is the reverse scan current value under the target voltage, and I2-I1 is the difference. This is the ratio calculated by taking the first term (the ratio of the forward scan current value) and the second term (the ratio of the reverse scan current value). It is a ratio calculated by taking the first term of the reverse scan current value as the ratio and the second term of the forward scan current value as the ratio.
[0122] This application provides a photovoltaic cell IV testing device. For example... Figure 7 As shown, the photovoltaic cell IV test device includes: parameter acquisition module 710, test module 730 and downsampling module 750.
[0123] The parameter acquisition module 710 is used to acquire the set target sampling parameters. The test module 730 is used to output a scan voltage to the photovoltaic cell for IV testing, and to collect the initial IV test data obtained by the IV test at a preset sampling rate. The downsampling module 750 is used to obtain the target IV test data corresponding to the target sampling parameters from the initial IV test data using a downsampling method.
[0124] In some embodiments, the preset sampling rate is the maximum sampling rate that the IV detection device can set.
[0125] In some embodiments, the target sampling parameter includes the target sampling data volume. The downsampling module 750 is further configured to downsample the initial IV test data to obtain target IV test data with a data volume equal to the target sampling data volume.
[0126] In some embodiments, the downsampling module 750 is further configured to: downsample the initial IV test data using an equally spaced sampling method to obtain target IV test data corresponding to the target sampling parameters.
[0127] In some embodiments, the photovoltaic cell IV testing apparatus further includes a filtering and compensation module for filtering the initial IV test data and performing amplitude compensation on the filtered initial IV test data to obtain compensated initial IV test data. Correspondingly, the downsampling module 750 obtains the target IV test data corresponding to the target sampling parameters from the compensated initial IV test data using a downsampling method.
[0128] In some embodiments, the filtering compensation module further employs a 0-phase filter to perform data filtering on the initial IV test data.
[0129] In some embodiments, the parameter acquisition module 710 is further configured to acquire set power control parameters. These power control parameters include a scan voltage range and a scan time. The test module 730 outputs a scan voltage to the photovoltaic cell at a preset sampling rate according to the power control parameters to perform IV testing, ensuring that the scan voltage is within the scan voltage range and the scan duration reaches the corresponding scan time.
[0130] This application also provides a performance testing device for photovoltaic cells, for reference... Figure 8 The performance testing device for photovoltaic cells includes a parameter configuration module 810 and a data processing module 830.
[0131] The parameter configuration module 810 is used to obtain target IV test data using the aforementioned photovoltaic cell IV test method. The data processing module 830 is used to perform hysteresis compensation processing on the target IV test data to obtain hysteresis-compensated IV test data; and to obtain the performance parameters of the photovoltaic cell based on the hysteresis-compensated IV test data.
[0132] For example Figure 9 As shown, after receiving user instructions, the parameter configuration module 810 can send commands to the IV testing device, causing the IV testing device to test the photovoltaic cell using the aforementioned photovoltaic cell IV testing method to obtain target IV test data. After obtaining the target IV test data, the IV testing device sends it to the data processing module 830 for data processing.
[0133] In some embodiments, the photovoltaic cell performance testing device further includes a preprocessing module for filtering the target IV test data acquired by the parameter configuration module 810.
[0134] In some embodiments, the preprocessing module further includes calibrating the target IV test data according to a selected correction standard.
[0135] In some embodiments, the data processing module 830 includes a hysteresis compensation unit and a performance parameter extraction unit. The hysteresis compensation unit is used to perform hysteresis compensation processing on the target IV test data to obtain hysteresis-compensated IV test data. The performance parameter extraction unit is used to obtain the performance parameters of the photovoltaic cell based on the hysteresis-compensated IV test data.
[0136] Specifically, the target IV test data includes forward scan IV test data and reverse scan IV test data. The hysteresis compensation unit is further used to: generate a forward scan IV curve based on the forward scan IV test data, and generate a reverse scan IV curve based on the reverse scan IV test data; determine the forward scan current value and reverse scan current value corresponding to multiple target voltage values in the forward scan IV curve and the reverse scan IV curve, respectively; determine the target current value corresponding to the target voltage value according to the reverse scan current value and the forward scan current value under any target voltage value, so as to obtain the target current value corresponding to each target voltage value, and use multiple target voltage values and corresponding target current values as IV test data for hysteresis compensation processing.
[0137] In some embodiments, the operation of the hysteresis compensation unit to determine the target current value corresponding to the target voltage value based on the back-scan current value and the forward-scan current value under any target voltage value includes: calculating the difference between the back-scan current value and the forward-scan current value under the target voltage, the difference being the sum of a first difference portion and a second difference portion, the first difference portion being the difference between the forward-scan current value and the target current value, and the second difference portion being the difference between the back-scan current value and the target current value; calculating the ratio between the forward-scan current value and the back-scan current value under the target voltage, the ratio being used as the ratio of the corresponding first difference portion and the second difference portion; and calculating the target current value corresponding to the target voltage value based on the forward-scan current value / back-scan current value under the target voltage, the ratio, and the difference.
[0138] It should be understood that the specific features, operations, and details described above with respect to the method of this application can also be similarly applied to the apparatus of this application, or vice versa. Furthermore, each step of the method of this application described above can be performed by a corresponding component or unit of the apparatus of this application.
[0139] It should be understood that the various modules / units of the device of this application can be implemented wholly or partially through software, hardware, firmware, or a combination thereof. Each module / unit can be embedded in the processor of the electronic device in hardware or firmware form or independent of the processor, or it can be stored in the memory of the electronic device in software form for the processor to call to execute the operation of each module / unit. Each module / unit can be implemented as an independent component or module, or two or more modules / units can be implemented as a single component or module.
[0140] This application provides an IV detection device 900, which is an electronic device. For example... Figure 10 As shown, the IV testing device includes a processor 901 and a memory 902 storing computer program instructions. The processor 901 executes the computer program instructions to implement the steps of the aforementioned photovoltaic cell IV testing method.
[0141] In one embodiment, the IV detection device 900 may include a processor, memory, network interface, communication interface, etc., connected via a system bus. The processor of the IV detection device 900 can provide the necessary computing, processing, and / or control capabilities. The memory of the IV detection device 900 may include non-volatile storage media and internal memory. The non-volatile storage media may store an operating system, computer programs, etc. The internal memory can provide an environment for the operation of the operating system and computer programs in the non-volatile storage media. The network interface and communication interface of the IV detection device 900 can be used to connect and communicate with external devices via a network. When the computer program is executed by the processor, it performs the steps of the method of this application.
[0142] In addition, this application provides a computer-readable storage medium storing computer program instructions, which, when executed by a processor, implement the above-described photovoltaic cell IV test method or the above-described photovoltaic cell performance testing method.
[0143] Those skilled in the art will understand that the method steps of this application can be performed by a computer program instructing related hardware, such as the IV detection device 900 or a processor. The computer program can be stored in a non-transitory computer-readable storage medium, and its execution causes the steps of this application to be performed. Depending on the context, any reference herein to memory, storage, or other media may include non-volatile or volatile memory. Examples of non-volatile memory include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), flash memory, magnetic tape, floppy disk, magneto-optical data storage device, optical data storage device, hard disk, solid-state drive, etc. Examples of volatile memory include random access memory (RAM), external cache memory, etc.
[0144] The technical features described above can be combined arbitrarily. Although not all possible combinations of these technical features are described, any combination of these technical features should be considered to be covered by this specification, provided that such combination does not contain contradictions.
[0145] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application 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 or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.
Claims
1. A photovoltaic cell IV test method, characterized in that, Applied to IV testing equipment, the method includes: Obtain the set target sampling parameters; A scanning voltage is output to the photovoltaic cell to perform IV testing, and the initial IV test data obtained from the IV test is acquired at a preset sampling rate. Target IV test data corresponding to the target sampling parameters are obtained from the initial IV test data using a downsampling method.
2. The method according to claim 1, characterized in that, The target sampling parameters include the target sampling data volume; obtaining the target IV test data corresponding to the target sampling parameters from the initial IV test data using a downsampling method includes: The initial IV test data is downsampled to obtain target IV test data with a data volume equal to the target sampled data volume.
3. The method according to claim 1, characterized in that, The step of obtaining target IV test data corresponding to the target sampling parameters from the initial IV test data using a downsampling method includes: The initial IV test data is downsampled using an equally spaced sampling method to obtain the target IV test data corresponding to the target sampling parameters.
4. The method according to claim 1, characterized in that, Before obtaining the target IV test data corresponding to the target sampling parameters from the initial IV test data using a downsampling method, the method further includes: The initial IV test data is then filtered. Amplitude compensation is performed on the initial IV test data after data filtering to obtain the compensated initial IV test data. The step of obtaining target IV test data corresponding to the target sampling parameters from the initial IV test data using a downsampling method includes: Target IV test data corresponding to the target sampling parameters are obtained from the compensated initial IV test data using a downsampling method.
5. The method according to claim 4, characterized in that, The data filtering of the initial IV test data includes: The initial IV test data were filtered using a 0-phase filter.
6. The method according to claim 1, characterized in that, Also includes: Obtain the set power control parameters; The step of outputting a scanning voltage to the photovoltaic cell for IV testing includes: According to the power control parameters, a scanning voltage is output to the photovoltaic cell at a preset sampling rate for IV testing.
7. A performance testing method for photovoltaic cells, applied to a host computer, characterized in that, Includes the following steps: The target IV test data are obtained using the photovoltaic cell IV test method according to any one of claims 1-6; Hysteresis compensation processing is performed on the target IV test data to obtain hysteresis-compensated IV test data; The performance parameters of the photovoltaic cells were obtained from the IV test data after hysteresis compensation.
8. The method according to claim 7, characterized in that, The target IV test data includes forward scan IV test data and reverse scan IV test data; the hysteresis compensation processing performed on the target IV test data to obtain hysteresis-compensated IV test data includes: A forward scan IV curve is generated based on the forward scan IV test data, and a reverse scan IV curve is generated based on the reverse scan IV test data; Determine the corresponding forward scan current value and reverse scan current value in the forward scan IV curve and the reverse scan IV curve, respectively, for multiple target voltage values; Based on the reverse scan current value and the forward scan current value at any target voltage value, the target current value corresponding to the target voltage value is determined to obtain the target current value corresponding to each target voltage value. The multiple target voltage values and the corresponding target current values are used as IV test data for hysteresis compensation processing.
9. A photovoltaic cell IV testing device, characterized in that, The device includes: The parameter acquisition module is used to acquire the set target sampling parameters; The test module is used to output a scanning voltage to the photovoltaic cell for IV testing and to collect the initial IV test data obtained by the IV test at a preset sampling rate. The downsampling module is used to obtain target IV test data corresponding to the target sampling parameters from the initial IV test data using a downsampling method.
10. A performance testing device for photovoltaic cells, characterized in that, include: The parameter configuration module is used to obtain target IV test data using the photovoltaic cell IV test method described in any one of claims 1-6; The data processing module is used to perform hysteresis compensation processing on the target IV test data to obtain hysteresis-compensated IV test data; and to obtain the performance parameters of the photovoltaic cell based on the hysteresis-compensated IV test data.
11. An IV testing device, characterized in that, include: Processor and memory storing computer program instructions; When the processor executes the computer program instructions, it implements the steps of the method according to any one of claims 1 to 6.
12. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the method according to any one of claims 1 to 6, or when executed by a processor, implements the steps of the method according to any one of claims 7 to 8.