CN112994616B

CN112994616B - Photovoltaic cell scanning control method and device and electronic equipment

Info

Publication number: CN112994616B
Application number: CN202110357317.0A
Authority: CN
Inventors: 于天; 金山; 张志魁
Original assignee: Dreiserco Langfang Technology Co ltd
Current assignee: Dreiserco Langfang Technology Co ltd
Priority date: 2021-04-01
Filing date: 2021-04-01
Publication date: 2022-06-07
Anticipated expiration: 2041-04-01
Also published as: CN112994616A

Abstract

The present disclosure relates to the field of photovoltaic cell technologies, and in particular, to a method and an apparatus for controlling scanning of a photovoltaic cell, and an electronic device. The scanning control method of the photovoltaic cell comprises the following steps: determining a first test interval, and performing first scanning operation on the photovoltaic cell at a first scanning speed to obtain a plurality of first power values; determining a first power maximum test value; determining a second test interval based on the first maximum power test value; performing a second scanning operation on the photovoltaic cell at a second scanning speed to obtain a plurality of second power values, wherein the second scanning speed is less than the first scanning speed; a second power max test value is determined. According to the scanning control method and device for the photovoltaic cell and the electronic equipment, the problem that the maximum power point of the photovoltaic cell cannot be accurately tested due to the capacitance effect of the photovoltaic cell can be solved, and the accuracy of testing the maximum power point of the photovoltaic cell can be improved through two scanning operations.

Description

Photovoltaic cell scanning control method and device and electronic equipment

Technical Field

The present disclosure relates to the field of photovoltaic cell technologies, and in particular, to a method and an apparatus for controlling scanning of a photovoltaic cell, and an electronic device.

Background

Research on the cell characteristics of photovoltaic cells, the maximum power point of which is a main parameter characterizing the characteristics of photovoltaic cells, has been one of important issues in the field of photovoltaic cell technology.

Generally, when a maximum power point of a photovoltaic cell is tested, when voltage changes, due to the equivalent parallel capacitance effect of the photovoltaic cell, a photo-generated current changes, and further, an error is caused in the maximum power point test of the photovoltaic cell, so that a test result is inaccurate. With the development of photovoltaic cell technology and the continuous improvement of cell efficiency, the problem of maximum power point test error caused by the capacitance effect of the photovoltaic cell is more and more prominent, so that the maximum power point of the photovoltaic cell cannot be accurately tested.

Disclosure of Invention

In view of the problem that the maximum power point of the photovoltaic cell cannot be accurately tested due to the capacitance effect of the photovoltaic cell, the application provides a scanning control method and device of the photovoltaic cell and electronic equipment. According to the scanning control method and device for the photovoltaic cell and the electronic equipment, the accuracy of testing the maximum power point of the photovoltaic cell can be improved through two scanning operations with different scanning speeds.

A first aspect of the present application provides a method for controlling scanning of a photovoltaic cell, where the method for controlling scanning of a photovoltaic cell includes: determining a first test interval, and performing a first scanning operation on the photovoltaic cell at a first scanning speed based on a plurality of first test values in the first test interval to obtain a plurality of first power values of the photovoltaic cell corresponding to the plurality of first test values; determining a first power maximum test value corresponding to a maximum power value of the plurality of first power values; determining a second test interval based on the first power maximum test value; performing a second scanning operation on the photovoltaic cell at a second scanning speed based on a plurality of second test values in the second test interval to obtain a plurality of second power values of the photovoltaic cell corresponding to the plurality of second test values, wherein the second scanning speed is less than the first scanning speed; determining a maximum power value of the plurality of second power values and a second power maximum test value corresponding to a maximum power value of the plurality of second power values.

Optionally, determining a second test interval based on the first power maximum test value may include: determining a difference value between the first power maximum test value and a first offset as a first endpoint value of the second test interval; determining a sum of the first power maximum test value and a second offset as a second endpoint value of the second test interval; determining the second test interval based on a first endpoint value of the second test interval and a second endpoint value of the second test interval.

Optionally, the first endpoint value of the second test interval is greater than the first endpoint value of the first test interval, and the second endpoint value of the second test interval is less than the second endpoint value of the first test interval.

Optionally, the method for controlling the scanning of the photovoltaic cell may further include: performing a third scanning operation on the photovoltaic cell based on a plurality of third test values in a third test interval; performing a fourth scan operation on the photovoltaic cell based on a plurality of fourth test values in a fourth test interval, wherein the third test interval is determined by: determining a first endpoint value of a third test interval based on the first endpoint value of the first test interval; determining a second endpoint value for the third test interval based on the first endpoint value for the second test interval; determining the third test interval based on a first endpoint value and a second endpoint value of the third test interval, wherein the fourth test interval is determined by: determining a first endpoint value of the fourth test interval based on a second endpoint value of the second test interval; determining a second endpoint value of a fourth test interval based on the second endpoint value of the first test interval; determining the fourth test interval based on the first endpoint value and the second endpoint value of the fourth test interval.

Optionally, the method for controlling the scanning of the photovoltaic cell may further include: determining the plurality of third test values according to the first endpoint value of the first test interval, the first endpoint value of the second test interval and the second scanning speed; determining the plurality of fourth test values according to the second endpoint value of the first test interval, the second endpoint value of the second test interval, and the second scan speed.

Optionally, determining the plurality of third test values according to the first endpoint value of the first test interval, the first endpoint value of the second test interval, and the second scan speed may include: determining a quadratic curve of the third test interval changing along with the scanning time according to the first endpoint value of the first test interval, the first endpoint value of the second test interval and the second scanning speed; determining the plurality of third test values based on a quadratic curve of the third test interval over a scan time, the plurality of fourth test values being determined according to the second endpoint value of the first test interval, the second endpoint value of the second test interval, and the second scan speed, including: determining a quadratic curve of the fourth test interval changing along with the scanning time according to the second endpoint value of the first test interval, the second endpoint value of the second test interval and the second scanning speed; determining the plurality of fourth test values based on a quadratic curve of the fourth test interval as a function of scan time.

Optionally, the first scanning operation is a forward scanning or a reverse scanning, and the second scanning operation is a forward scanning.

A second aspect of the present application provides a scanning control device of a photovoltaic cell, including: the first scanning unit is used for determining a first test interval, and performing first scanning operation on the photovoltaic cell at a first scanning speed based on a plurality of first test values in the first test interval to obtain a plurality of first power values of the photovoltaic cell corresponding to the plurality of first test values; a first determination unit that determines a first power maximum test value corresponding to a maximum power value among the plurality of first power values; an interval determination unit which determines a second test interval based on the first maximum power test value; the second scanning unit is used for carrying out second scanning operation on the photovoltaic cell at a second scanning speed based on a plurality of second test values in the second test interval to obtain a plurality of second power values of the photovoltaic cell corresponding to the plurality of second test values, wherein the second scanning speed is smaller than the first scanning speed; a second determination unit that determines a maximum power value of the plurality of second power values and a second power maximum test value corresponding to a maximum power value of the plurality of second power values.

A third aspect of the present application provides an electronic device, comprising: a processor; a memory storing a computer program which, when executed by the processor, implements a method of controlling scanning of a photovoltaic cell as set forth in the first aspect of the present application.

A fourth aspect of the present application provides a computer-readable storage medium storing a computer program which, when executed, implements the method of controlling the scanning of a photovoltaic cell according to the first aspect of the present application.

In order to make the aforementioned objects, features and advantages of the present application more comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained from the drawings without inventive effort.

Fig. 1 shows a scanning schematic of a scanning control method of a photovoltaic cell according to the prior art;

FIG. 2 shows a schematic diagram of a photovoltaic cell characterization test system according to an exemplary embodiment of the present application;

fig. 3a and 3b show schematic block circuit diagrams of a photovoltaic cell characterization test system according to an exemplary embodiment of the present application;

fig. 4 shows a schematic flow diagram of a method of scan control of a photovoltaic cell according to an exemplary embodiment of the present application;

fig. 5a shows a scanning schematic of an example of a method of controlling the scanning of a photovoltaic cell according to an exemplary embodiment of the present application;

fig. 5b shows a scanning schematic of another example of a scanning control method of a photovoltaic cell according to an exemplary embodiment of the present application;

fig. 6a and 6b show scanning schematics of a continuous scan of a scanning control method of a photovoltaic cell according to an exemplary embodiment of the present application;

fig. 7a, 7b and 7c show a scan curve smoothing diagram of a full-range scan operation in a scan control method of a photovoltaic cell according to an exemplary embodiment of the present application;

fig. 8 shows a scanning trend diagram of a scanning control method of a photovoltaic cell according to an exemplary embodiment of the present application;

fig. 9 shows a schematic diagram comparing test results of a scan control method of a photovoltaic cell according to an exemplary embodiment of the present application with a scan control method of a photovoltaic cell according to the related art;

fig. 10 shows a schematic block diagram of a scanning control device of a photovoltaic cell according to an exemplary embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all the embodiments. The components of the embodiments of the present application, generally described and illustrated in the figures herein, can be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present application, presented in the accompanying drawings, is not intended to limit the scope of the claimed application, but is merely representative of selected embodiments of the application. Every other embodiment that can be obtained by a person skilled in the art without making creative efforts based on the embodiments of the present application falls within the protection scope of the present application.

It should be noted that in the embodiments of the present application, the term "comprising" is used to indicate the presence of the features stated hereinafter, but does not exclude the addition of further features. Furthermore, reference to "photovoltaic cell" in this application may refer to a single photovoltaic cell, but may also refer to a photovoltaic cell assembly or photovoltaic cell device comprising a plurality of photovoltaic cells.

One aspect of the present application relates to a scan control method of a photovoltaic cell. The method can improve the accuracy of testing the maximum power point of the photovoltaic cell, reduce the requirement on a test light source, has universality for different types of photovoltaic cells, and can be suitable for the test requirements of different stages and different test conditions in the production and use of the photovoltaic cell.

The tested current is affected by the charging/discharging of the equivalent parallel capacitance and is inaccurate due to the equivalent parallel capacitance effect of the photovoltaic cell itself, and particularly, the tested current is actually a superposition value of the photo-generated current and the charging/discharging current of the equivalent parallel capacitance, and the influence of such capacitance effect becomes larger as the change rate of the scanning voltage increases.

Before the application of the present application, in order to avoid or reduce the aggravation of the capacitance effect of the photovoltaic cell itself caused by the excessive voltage change rate during the testing process of the maximum power of the photovoltaic cell in the prior art, a continuous light source with the voltage change rate of approximately 0 is usually selected to test the photovoltaic cell, which has a high requirement on the light source.

In this regard, in the prior art method for testing the maximum power of the photovoltaic cell, a pulsed light source with a wider pulse width is also selected for testing, as shown in fig. 1, the photovoltaic cell may be scanned under the pulsed light source with an effective pulse width of 70ms, for example, forward scanning and reverse scanning may be performed, the voltage is ramped during the scanning process, and the maximum power region may be determined up to the open-circuit voltage, for example, the open-circuit voltage is 48V. As shown in fig. 1, in the maximum power region, the voltage is kept ramping up with a constant slope, and the rate of change is large. In this case, there is a large difference between the forward scan voltage characteristic curve (IV curve) and the reverse scan voltage characteristic curve (IV curve) of the photovoltaic cell, and accordingly, there is also a large difference between the maximum power value obtained in the forward scan IV curve and the reverse scan voltage characteristic curve and the voltage value corresponding to the maximum power value, which indicates that the test result is inaccurate, mainly because, in the case of using a pulsed light source, it is difficult to reduce the voltage change rate, so that the voltage change rate (such as the slope of the voltage curve in fig. 1) is much greater than zero, resulting in a significant influence of the capacitance effect on the test result.

The scanning control method of the photovoltaic cell of the present application will be described in detail below with reference to fig. 2, fig. 3a, fig. 3b and fig. 4, wherein fig. 2, fig. 3a and fig. 3b show a schematic diagram and a system circuit block diagram of a photovoltaic cell characteristic test system, respectively.

Specifically, as shown in fig. 2, the photovoltaic cell characteristic test system according to the embodiment of the present application may include a light source 2, and the light source 2 may be used to generate a light field for irradiating the photovoltaic cell 5 to be tested. The photovoltaic cell 5 to be tested can be mounted on a cell holder 4. Preferably, the parameters of the light source 2 may be close to the parameters of sunlight, e.g. the irradiance, uniformity, spectral compliance, etc. of the light source 2 may be close to sunlight. The light source 2 may be a xenon lamp, for example. The light source 2 may be mounted on the light source holder 11 and may be powered by the power cabinet 1.

The light source 2 may be a steady state light source or a pulsed light source. In general, a steady-state light source may produce a stable irradiance that can be used to illuminate a photovoltaic cell over a longer period of time (e.g., greater than 1 second). Therefore, the capacitance characteristic of the tested battery can be better overcome in the test process. In contrast, pulsed light sources can provide irradiation that can be used to irradiate photovoltaic cells with a stable time that is short, typically not more than 1 second. Since the testing method according to the present application has a fast testing speed and a good universality, a steady-state light source can be used as the irradiation light source or a pulse light source can be used as the irradiation light source in the test using the method of the present application, which will be described in detail below.

The photovoltaic cell characteristic test system may further include a partition plate 3, and the partition plate 3 may be used to partition ambient light other than the light emitted from the light source 2, where the partition plate 3 may physically partition the light from the structure, and may be configured to selectively transmit light of a predetermined wavelength/wavelength range (for example, the wavelength range of the light source 2).

As shown in fig. 2 and 3a, the photovoltaic cell characteristic testing system according to the present application may include a variable load 6. The variable load 6 may control the sweep of the photovoltaic cells under test, where sweeping refers to controlling the load size of the variable load 6 such that the amount of sweep (e.g., voltage or current) varies within a predetermined test interval. In another example, the precision resistor of fig. 3b can also be used as a variable load to test the maximum power point of a photovoltaic cell.

Generally, the sweep control of the variable load 6 may include a voltage sweep control and a current sweep control. In the voltage sweep control, a sweep control loop, which aims at controlling the output voltage of the photovoltaic cell under test, causes the voltage of the photovoltaic cell under test to vary within a predetermined test interval during the test, for example, the voltage variation covers a range from 0 to an open-circuit voltage or a range from the open-circuit voltage to 0. Similarly, in the current sweep control, a sweep control loop that aims at controlling the output current of the photovoltaic cell under test is made such that the current of the photovoltaic cell under test varies within a predetermined test interval during the test, for example, such that the current variation covers a range from 0 to a short-circuit current or a range from a short-circuit current to 0.

The variable load 6 can simulate the process from short circuit to open circuit (for example, it can be called forward sweep) or from open circuit to short circuit (for example, it can be called reverse sweep), so that the parameters of short circuit current, open circuit voltage and maximum power value and corresponding maximum power point of the tested photovoltaic cell can be measured. Preferably, in the case of a pulsed light source, the variable load 6 may control the scanning action to be completed within the pulse width time during which the pulsed light source is active.

Further, preferably, the photovoltaic cell characteristic test system according to the present application may further include a monitor cell 10. The monitoring cell 10 may be used to monitor the light intensity, temperature, etc. of the system, and particularly, the light intensity and temperature may be unstable during an actual test, and the amount of change in the light intensity and temperature may be determined by monitoring the value output from the cell 10, whereby the output characteristics of the measured photovoltaic cell may be corrected based on the amount of change.

Further, the photovoltaic cell characteristic test system may further include a printer 7, a computer 8, and a foot switch 9. The foot switch 9 may be used to control the test operation, such as starting and ending the test, which may be manually controlled by an operator. However, the foot switch 9 may not be provided in the photovoltaic cell characteristic test system, and the test operation may be controlled by the computer 8 or other controller software.

Although not shown in fig. 2, as shown in fig. 3a, the photovoltaic cell characteristic testing system according to the present application may further include a temperature monitoring device, and the temperature monitoring device may have a temperature probe for monitoring the temperature of the battery under test to ensure that the battery under test is in a stable temperature range during the testing process, and the testing may be stopped in time when the temperature monitoring device monitors that the temperature of the battery under test is too high.

In addition, as shown in fig. 3a, the photovoltaic cell characteristic testing system according to the present application may further include a measuring instrument, and the measuring instrument may measure the voltage and the current at the output end of the battery to be tested as the variable load 6 completes the scanning process within the predetermined light source irradiation time, so that a volt-ampere characteristic curve may be obtained according to the measured voltage and current to determine characteristic parameters such as open-circuit voltage, short-circuit current, and maximum power value and corresponding maximum power point. Preferably, the measuring device can meet the measuring requirements for a relatively short irradiation time, for example for a pulse width time during which the pulsed light source is active.

The scanning control method of the photovoltaic cell of the present application will be described in detail below with reference to fig. 4. The scanning control method of the photovoltaic cell comprises the following steps:

s1, determining a first test interval, and performing a first scanning operation on the photovoltaic cell at a first scanning speed based on a plurality of first test values in the first test interval to obtain a plurality of first power values of the photovoltaic cell corresponding to the plurality of first test values.

In this step, the first scan operation may be performed by adjusting the variable load described above such that the first test value varies in the first test interval. As an example, a plurality of first test values may be selected from the first test interval at equal intervals, and the photovoltaic cell may be subjected to a first scanning operation at the plurality of first test values. However, the present application is not limited thereto, and a plurality of first test values may be randomly selected.

The first test value may be a voltage, but the present application is not limited thereto, and although the process of testing the maximum power of the photovoltaic cell is described in the embodiment of the present application by taking the voltage as the test value as an example, it is understood that the first test value may also be a current, and the process of testing the maximum power of the photovoltaic cell by taking the current as the test value is similar to the process of voltage sweep described in the embodiment of the present application, and a person skilled in the art can make reasonable adjustments according to actual needs.

In an example, the first scan operation may be a forward scan operation, where the forward scan may represent a process from a short circuit to an open circuit. Accordingly, the first test interval may be determined from 0V to the open circuit voltage of the photovoltaic cell, i.e., [0, VOC ], where VOC represents the open circuit voltage of the photovoltaic cell. In this manner, the entire voltage variation range of the photovoltaic cell from 0V to the open circuit voltage can be traversed during the first scanning operation.

In another example, in order to ensure that the first scan operation passes through a voltage test value of 0V and a voltage test value of an open circuit voltage during the test, the range of the first test interval may be determined to include [0, VOC ], for example, as shown in fig. 5a, the first endpoint value V1 of the first test interval may be less than 0V, which is a negative value, and the second endpoint value V2 of the first test interval may be greater than the open circuit voltage VOC, where the first endpoint value V1 and the second endpoint value V2 may be arbitrarily selected according to actual conditions as long as they satisfy the above conditions. In this way, it is possible to reduce the requirement for the adjustment accuracy of the variable load, i.e., even if the variable load cannot be adjusted accurately so that the voltage is at 0V and VOC, the test can be completed. In the drawings of the embodiments of the present application, V denotes a voltage, which may be in volt-ampere units, for example, and t denotes a time, which may be in milliseconds, for example. However, the units of the parameters given in the embodiments of the present application are merely exemplary, and can be adjusted according to actual needs.

In yet another example, the first scan operation may be a reverse scan operation, where the reverse scan may represent a process from an open circuit to a short circuit. Accordingly, as shown in fig. 5b, the first test interval may be determined as [ VOC,0 ].

Further, similar to the above description, in order to be able to ensure that the first scan operation passes through the voltage test value of the open-circuit voltage VOC and the voltage test value of 0V, the range of the first test interval may be determined to include [ VOC,0] during the reverse scan, for example, a first end value of the first test interval may be greater than the open-circuit voltage VOC, and a second end value thereof may be less than 0V, being a negative value.

In the embodiment of the present application, the scan speed may refer to a variation rate of the test value during the scan operation, for example, the test value is derived from time. For example, the first scanning speed may refer to a rate of change of the first test value during the first scanning operation, e.g., the first test value is derived over time.

As an example, during the constant scan in which the variation rate of the test value is constant, the scan speed may be a slope between two end values of the test interval, and as shown in fig. 5a, the first scan speed of the first scan operation may be (V2-V1)/(t1-t 0). However, the first scanning operation according to the present application is not limited to the constant speed scanning, and the scanning may be performed in other variable speed scanning such as a quadratic curve form, for example, in the case of performing the variable speed scanning in the quadratic curve form, a quadratic curve passing through the first endpoint value and the second endpoint value of the first test section may be determined, and then a plurality of first test values may be selected on the curve, and the first scanning operation may be performed with the first endpoint value, the second endpoint value, and the plurality of first test values therebetween. In the case where the first scanning operation is the variable speed scanning, the first scanning speed may be an average speed during the first scanning operation.

During the execution of the first scanning operation, a plurality of first power values corresponding to a plurality of test values may be obtained.

Specifically, in the case where the first test value is a voltage test value, current values corresponding to the plurality of first test values may be detected during the first scanning operation to obtain a plurality of first power values corresponding to the plurality of first test values based on the plurality of first test values and the detected corresponding current values.

In a case where the first test value is a current test value, voltage values corresponding to the plurality of first test values may be detected during the first scanning operation to obtain a plurality of first power values corresponding to the plurality of first test values based on the plurality of first test values and the detected corresponding voltage values.

S2, determining a first power maximum test value corresponding to a maximum power value of the plurality of first power values.

In this step, a maximum power value among the plurality of first power values may be determined by comparing the plurality of first power values obtained in the first scanning operation, and a first test value corresponding to the maximum power value may be determined as a first power maximum test value, which is Vpmax, as shown in fig. 5a and 5 b.

Under the condition that the first test value is a voltage test value, the first maximum power test value is a voltage value; in the case where the first test value is a current test value, the first power maximum test value is a current value.

And S3, determining a second test interval based on the first power maximum test value.

In this step, the second test interval may include the first power max test value. As an example, the second test interval may be contained within the first test interval, where contained within the first test interval refers to: the lower limit value of the second test interval is greater than the lower limit value of the first test interval, and the upper limit value of the second test interval is less than the upper limit value of the first test interval; or the upper limit value of the second test interval is smaller than the lower limit value of the first test interval, and the lower limit value of the second test interval is larger than the upper limit value of the first test interval.

As an example, the step of determining the second test interval based on the first power max test value may comprise:

s31, determining the difference value between the first power maximum test value and the first offset as a first endpoint value of a second test interval; s32, determining the sum of the first power maximum test value and the second offset as a second endpoint value of a second test interval; s33, determining a first interval based on the first endpoint value and the second endpoint value.

In step S31, as described above, in fig. 5a and 5b, the first power maximum test value may be Vpmax, which may be different from the first offset by a first endpoint value V1' of the second test interval, where the first offset may be a preset value, which may make the first endpoint value of the second test interval greater than the first endpoint value of the first test interval.

In step S32, as described above, in fig. 5a and 5b, the first power maximum test value may be Vpmax, and the sum of the first offset and the second offset may be the second endpoint value V2' of the second test interval, where the second offset may be a preset value, which may make the second endpoint value of the second test interval smaller than the second endpoint value of the first test interval.

In the above steps S31 and S32, as an example, the maximum power values of the plurality of photovoltaic cells in the batch of photovoltaic cells may be tested, and the size of the second test interval may be determined according to the maximum power values of the plurality of photovoltaic cells to be tested, for example, the second test interval may be set to include the maximum power values of the plurality of photovoltaic cells to be tested.

In step S33, one and the other of the first endpoint value and the second endpoint value may be used as a lower limit value and an upper limit value of the second test interval, respectively.

Specifically, in the case where the first endpoint value is a lower limit value of the second test interval, the second endpoint value is an upper limit value of the second test interval; in case the first endpoint value is the upper limit value of the second test interval, the second endpoint value is the lower limit value of the second test interval.

And S4, performing a second scanning operation on the photovoltaic cell at a second scanning speed based on a plurality of second test values in a second test interval to obtain a plurality of second power values of the photovoltaic cell corresponding to the plurality of second test values, wherein the second scanning speed is less than the first scanning speed.

In this step, the second scan operation may be performed by adjusting the variable load described above such that the second test value varies in the second test interval. As an example, a plurality of second test values may be selected from the second test interval at equal intervals, and the second scanning operation is performed on the photovoltaic cell according to the plurality of second test values. However, the present application is not limited thereto, and a plurality of second test values may be randomly selected.

The second test value may be a voltage, but the present application is not limited thereto, and although the process of testing the maximum power of the photovoltaic cell is described in the embodiment of the present application by taking the voltage as the test value as an example, it is understood that the second test value may also be a current, and the process of testing the maximum power of the photovoltaic cell by taking the current as the test value is similar to the process of voltage sweep described in the embodiment of the present application, and a person skilled in the art can make reasonable adjustments according to actual needs.

In an example, the second scan operation may be a forward scan operation. The first endpoint value of the second test interval may be a lower limit value of the second test interval, and the second endpoint value thereof may be an upper limit value of the second test interval.

In this example, in the case where the first scan operation is a forward scan operation, as shown in fig. 5a, the first end value of the second test interval may be greater than the lower limit value of the first test interval, for example, greater than 0V; the second endpoint value of the second test interval may be less than the upper limit value of the first test interval, e.g. less than the open circuit voltage VOC.

In the case where the first scan operation is a reverse scan operation, as shown in fig. 5b, the first end value of the second test interval may be greater than the upper limit value of the first test interval, for example, greater than 0V; the second endpoint value of the second test interval may be less than the lower limit of the first test interval, e.g., less than the open circuit voltage VOC.

In another example, the second scanning operation may be a reverse scanning operation. The first endpoint value of the second test interval may be the upper limit value of the second test interval, and the second endpoint value thereof may be the lower limit value of the second test interval.

In this example, in the case where the first scan operation is a forward scan operation, the first end value of the second test interval may be less than the upper limit value of the first test interval, for example, less than the open-circuit voltage VOC; the second endpoint value of the second test interval may be greater than the lower limit value of the first test interval, e.g. greater than 0V.

In the case where the first scan operation is a reverse scan operation, the first end value of the second test interval may be smaller than the upper limit value of the first test interval, for example, smaller than the open-circuit voltage VOC; the second endpoint value of the second test interval may be greater than the lower limit value of the first test interval, e.g. greater than 0V.

The second scan speed may refer to a rate of change of the second test value during the second scan operation, e.g., a derivative of the second test value with respect to time.

As an example, as shown in fig. 5a, the second scan speed of the second scan operation may be (V2 '-V1')/(t 3-t2), where the second scan speed may be less than the first scan speed, i.e., the change rate of the second test value may be made less than the change rate of the first test value, so that the second scan operation process is less affected by the equivalent parallel capacitance effect of the valley cell itself and is negligible.

However, the second scanning operation described above is not limited to the constant speed scanning, and may be performed in other variable speed scanning such as a quadratic curve form, for example, in the case of performing the variable speed scanning in the quadratic curve form, a quadratic curve of the first endpoint value and the second endpoint value passing through the second test interval may be determined, and then a plurality of second test values are selected on the curve, and the second scanning operation is performed in the first endpoint value, the second endpoint value, and the plurality of second test values therebetween. In the case where the second scanning operation is the variable speed scanning, the second scanning speed may be an average speed during the second scanning operation.

In the course of performing the second scan operation, a plurality of second power values corresponding to the plurality of test values may be obtained.

Specifically, in the case where the second test value is the voltage test value, current values corresponding to the plurality of second test values may be detected during the second scan operation to obtain a plurality of second power values corresponding to the plurality of second test values based on the plurality of second test values and the detected corresponding current values.

In a case where the second test value is a current test value, voltage values corresponding to the plurality of second test values may be detected during the second scan operation to obtain a plurality of first power values corresponding to the plurality of second test values based on the plurality of second test values and the detected corresponding voltage values.

And S5, determining a maximum power value in the plurality of second power values and a second test value corresponding to the maximum power value in the plurality of second power values.

In this step, a maximum power value among the plurality of second power values may be determined by comparing the plurality of second power values obtained in the second scanning operation to determine a second power maximum test value corresponding to the maximum power value.

Under the condition that the second test value is the voltage test value, the second power maximum test value is the voltage value; and under the condition that the second test value is the current test value, the second power maximum test value is the current value.

In the scan control method of a photovoltaic cell according to the embodiment of the present application, the variable load may be controlled to perform an IV curve scan operation twice within an effective pulse width, and in particular, as exemplarily shown in fig. 5a and 5b, a first scan operation (or referred to as an initial scan) may be performed for a short time to capture a first power maximum test value (or referred to as a maximum power point) Vpmax point of a first maximum power value pdot, and then a second scan operation (or referred to as a normal scan) may be performed according to the first power maximum test value Vpmax captured by the first scan operation, so that a second maximum power value may be tested within a second test interval including the first power maximum test value Vpmax, and since a second scan speed of the second scan operation may be less than the first scan speed of the first scan operation, a change rate of the test value of the second scan operation may be made smaller, the equivalent parallel capacitance effect of the photovoltaic cell is small and even negligible, so that the accuracy of the test result is improved, and the real maximum power value of the photovoltaic cell is found.

Further, in fig. 5a and 5b, instol denotes the flash effective pulse width of the light source, which may be, for example, in the range of 10ms to 100ms, but is not limited thereto, since the test method of the present application can allow the second scan speed in the second scan operation to be slowed down by two scans, thereby avoiding or at least alleviating the influence of the equivalent parallel capacitance effect of the photovoltaic cell on the test result, therefore, the scanning control method of the photovoltaic cell of the present application is applicable not only to a continuous light source capable of making a test value constant, but also to a pulsed light source having a shorter pulse width, in particular, even under the condition that the pulse width is small (for example, 10ms), the maximum power of the photovoltaic cell can be accurately tested, the requirement on a test light source is greatly reduced, and the method can be suitable for test processes under different test conditions.

In the above example, as shown in fig. 5a and 5b, both end point values of the first test interval are different from those of the second test interval, and thus the first scan operation and the second scan operation may be separately performed based on the first test interval and the second test interval, respectively.

In another example, continuous scanning of the two scanning operations may also be achieved by continuously operating the variable load. Fig. 6a shows a schematic diagram of a continuous scan in which both the first scan operation and the second scan operation are forward scans, and fig. 6b shows a schematic diagram of a continuous scan in which the first scan operation is a reverse scan and the second scan operation is a forward scan.

As shown in fig. 6a, after the first scan operation, the full-range scan operation from 0V to the open-circuit voltage VOC or from the open-circuit voltage VOC to 0V may be performed again. The full-range scan operation may include a third scan operation, a second scan operation (described in detail above), and a fourth scan operation, which are sequentially performed.

Specifically, the scanning control method for the photovoltaic cell according to the embodiment of the present application may further include: performing a third scanning operation on the photovoltaic cell based on a plurality of third test values in a third test interval; and performing a fourth scanning operation on the photovoltaic cell based on a plurality of fourth test values in a fourth test interval.

The third scan operation may be after the first scan operation and before the second scan operation as a transition interval from the first test interval to the second test interval.

As an example, the third test interval may be determined by: determining a first endpoint value of a third test interval based on the first endpoint value of the first test interval; determining a second endpoint value of a third test interval based on the first endpoint value of the second test interval; a third test interval is determined based on the first endpoint value and the second endpoint value of the third test interval.

In particular, in the case shown in fig. 6a, the first end point value of the third test interval may be determined as the first end point value of the first test interval (e.g. the lower limit value of the first test interval), and the second end point value of the third test interval may be determined as the first end point value of the second test interval (e.g. the lower limit value of the second test interval). In this case, after the first scan operation is performed, the variable load may be rapidly returned to an initial position (i.e., a position corresponding to the first endpoint value of the first test section), and then the third scan operation may be performed with the third test section from the initial position, and the first endpoint value of the second test section may be reached after the third test section is passed, and then the second scan operation may be continuously performed with the second test section, in which the variable load may be continuously adjusted, and the two measurements may be separately performed without disconnecting the circuit, improving the control of the circuit.

Further, since the third scan operation is a transition operation from the first scan operation to the second scan operation without finding a maximum power value, and the third scan speed of the third scan operation has no influence on the final test result, the third scan speed of the third scan operation may be greater than the second scan speed, the scan time of the third scan operation (t2-t5 in fig. 6 a) may be less than the scan time of the second scan operation (t3-t2 in fig. 6 a), and the scan time of the third scan operation may also be less than the scan time of the first scan operation (t1-t0 in fig. 6 a).

In the case shown in fig. 6b, the first end value of the third test interval may be determined as the second end value of the first test interval (e.g. the upper limit value of the first test interval) and the second end value of the third test interval may be determined as the first end value of the second test interval (e.g. the lower limit value of the second test interval). In this case, after the first scan operation is performed, the third scan operation may be continuously performed with the third test section, and after the third test section is passed, the first endpoint value of the second test section is reached, and then the second scan operation may be continuously performed with the second test section.

Similarly, the third scanning speed of the third scanning operation may be greater than the second scanning speed, the scanning time of the third scanning operation (t2-t1 in fig. 6 b) may be less than the scanning time of the second scanning operation (t3-t2 in fig. 6 b), and the scanning time of the third scanning operation may also be less than the scanning time of the first scanning operation (t1-t0 in fig. 6 b).

The fourth scanning operation may be performed after the second scanning operation. As an example, the fourth test interval may be determined by: determining a first endpoint value of a fourth test interval based on a second endpoint value of the second test interval; determining a second endpoint value of a fourth test interval based on the second endpoint value of the first test interval; a fourth test interval is determined based on the first endpoint value and the second endpoint value of the fourth test interval.

Specifically, in the case shown in fig. 6a, the first end point value of the fourth test interval may be determined as the second end point value of the second test interval (e.g. the upper limit value of the second test interval), and the second end point value of the fourth test interval may be determined as the second end point value of the first test interval (e.g. the upper limit value of the first test interval).

Further, the fourth scanning speed of the fourth scanning operation may be greater than the second scanning speed, the scanning time of the fourth scanning operation (t4-t3 in fig. 6 a) may be less than the scanning time of the second scanning operation (t3-t2 in fig. 6 a), and the scanning time of the fourth scanning operation may also be less than the scanning time of the first scanning operation (t1-t0 in fig. 6 a).

In the case shown in fig. 6b, the first end value of the fourth test interval may be determined as the second end value of the second test interval (e.g. the upper limit value of the second test interval) and the second end value of the fourth test interval may be determined as the first end value of the first test interval (e.g. the upper limit value of the first test interval).

Further, the fourth scanning speed of the fourth scanning operation may be greater than the second scanning speed, the scanning time of the fourth scanning operation (t4-t3 in fig. 6 b) may be less than the scanning time of the second scanning operation (t3-t2 in fig. 6 b), and the scanning time of the fourth scanning operation may also be less than the scanning time of the first scanning operation (t1-t0 in fig. 6 b).

In the example of fig. 6a and 6b, the first scanning operation, which may be used to preliminarily determine the range of maximum power points (i.e., the second test interval), and the full-range scanning operation, which may be used to obtain a complete test curve of the photovoltaic cell between 0V and the open-circuit voltage VOC as a formal test, may be performed continuously, in fact two complete scans of the photovoltaic cell between 0V and the open-circuit voltage VOC may be performed. In this way, continuous control of variable load during actual testing is facilitated, and a complete test curve of the photovoltaic cell between 0V and open-circuit voltage VOC can be obtained while determining the maximum power point.

Here, considering that three scan curves and two inflection points exist from the third scan operation to the second scan operation and from the second scan operation to the fourth scan operation in the above-described full-range scan operation, a slope of the voltage test value abruptly changes in the actual test operation, which may cause an abrupt change in the current, and a spike phenomenon may be formed on the scan curve, and thus, a smoothing process may be performed on a change in the test value variation between the third test interval and the second test interval or a change in the test value variation between the second test interval and the fourth test interval or changes in the two test value variations.

In an example, a median smoothing process may be performed on a change in the test value variation amount between the third test section and the second test section and/or a change in the test value variation amount between the second test section and the fourth test section.

Specifically, as shown in fig. 7a, the second endpoint value of the third test interval and the first endpoint value of the second test interval may be a point B, the corresponding test value may be V1 ', a point a near the point B may be determined in the third test interval, the corresponding test value may be Va, a point C near the point B may be determined in the second test interval, the corresponding test value may be Vc, and V1' may be (Va + Vc)/2, thereby implementing the median smoothing process for the point B. The median smoothing process of the change of the test value variation between the second test interval and the fourth test interval is similar to the above process, and is not described herein again. Here, fig. 7a is only a schematic diagram showing the median smoothing process, and thus specific coordinate axes are not shown.

In another example, the extended smoothing process may be performed on a change in the test value variation amount between the third test section and the second test section and/or a change in the test value variation amount between the second test section and the fourth test section.

Specifically, as shown in fig. 7B, the second endpoint value of the third test interval and the first endpoint value of the second test interval may be point B, and the corresponding test values may be V1', N points a near the point B may be determined in the third test interval, and N points C near the point B may be determined in the second test interval, where N is a positive integer greater than 1. A curve fitting may be performed based on the 2N +1 points, and the 2N +1 points may be re-determined on the fitted curve with the abscissa of the 2N +1 points. The process of the extension smoothing of the change of the test value variation between the second test interval and the fourth test interval is similar to the above process, and is not repeated here. Here, fig. 7b is only a schematic diagram illustrating the extended smoothing process, and thus specific coordinate axes are not illustrated.

In yet another example, the second-order curve smoothing process may be performed on a variation in the test value between the third test interval and the second test interval and/or a variation in the test value variation between the second test interval and the fourth test interval.

For example, in the case shown in fig. 6a, the method for controlling the scanning of the photovoltaic cell according to the embodiment of the present application may further include: determining a plurality of third test values according to the first endpoint value of the first test interval, the first endpoint value of the second test interval and the second scanning speed; and determining a plurality of fourth test values according to the second endpoint value of the first test interval, the second endpoint value of the second test interval and the second scanning speed.

Specifically, as shown in fig. 7c, the determining a plurality of third test values according to the first endpoint value of the first test interval, the first endpoint value of the second test interval, and the second scan speed may include: determining a quadratic curve of a third test interval changing along with the scanning time according to the first endpoint value of the first test interval, the first endpoint value of the second test interval and the second scanning speed; a plurality of third test values is determined based on a quadratic curve of the third test interval over the scan time.

In the above step, a quadratic form for smoothing the third test section may be established, for example, as shown in fig. 7c, the quadratic form for smoothing the third test section may be expressed as Y ═ b₁-m₁(x-a₁)²Wherein m is₁、a₁And b₁Is the unknown quantity to be determined. In the case shown in fig. 6a, the first endpoint value of the third test interval may be determined according to the first endpoint value of the first test interval, the second endpoint value of the third test interval may be determined according to the first endpoint value of the second test interval, and in order to achieve a smooth transition between the third test interval and the second test interval, the rate of change of the third test value at the intersection with the second test interval should be equal to the rate of change of the second test value at the intersection, and in the case shown in fig. 6a, the second test value changes at a constant speed, that is, the rate of change of the second test value is constant, and the rate of change of the second test value at the intersection is the second scanning speed (that is, the slope K in fig. 7 c).

Therefore, the above-described quadratic curve expression Y ═ b can be determined₁-m₁(x-a₁)²The coordinates (0, V1) of the first end point of the third test interval, the coordinates (t2, V1') of the second end point of the third test interval, and the second scanning speed K, so that a three-way equation system can be established according to the three known quantities to determine m₁、a₁And b₁The value of (c). Here, t2 denotes the scan time of the third scan operation, which may be determined according to the entire time of the full-range scan operation, for example, it may occupy 10% of the entire time of the full-range scan operation, but it is not limited thereto, and theoretically, it is better that t2 is smaller to allow the second scan operation to occupy more time throughout the entire process of the full-range scan operation, so that the second scan speed may be as small as possible at a timing of the second test interval. In the case shown in FIG. 7c, the second scanning speed K may be (V2 '-V1')/(t 3-t2), where (t3-t2) represents the scanning time of the second scanning operation, which may be based on the whole of the full-range scanning operationTime may be determined, for example, to account for 80% of the total time of the full-range scan operation (e.g., t4 in FIG. 7 c), but it is not limited thereto, and theoretically, the larger the (t3-t2) the better, so that the second scan speed may be as small as possible at the second test interval timing.

As an example, the second-order curve expression Y ═ b of the third test interval₁-m₁(x-a₁)²The specific solving process of (2) is as follows:

the coordinates (0, V1) and (t2, V1') may be respectively substituted into the quadratic curve expression Y ═ b₁-m₁(x-a₁)²The following expressions (1) and (2) are obtained:

V1＝b₁-m₁(-a₁)² (1)

V1′＝b₁-m₁(t2-a₁)² (2)

can be expressed in terms of a quadratic curve (Y ═ b)₁-m₁(x-a₁)²Derivation, the derivation expression can be expressed as the following formula (3):

Y′＝-2m₁(x-a₁) (3)

where Y' may be equal to the second scanning speed K, and thus, the above equation (3) may be expressed as:

K＝-2m₁(t2-a₁) (4)

in the above formulas (1), (2) and (4), V1, V1', t2 and K are known amounts, and therefore, it can be established about m₁、a₁And b₁Ternary system of equations of unknown quantity to solve for m according to mathematical methods₁、a₁And b₁The value of (c).

In solving for m₁、a₁And b₁After the value of (a), the quadratic curve expression Y of the third test interval may be determined as b₁-m₁(x-a₁)²A plurality of third test values may thus be selected based on the expression.

Similar to the step of determining the plurality of third test values described above, as an example, as shown in fig. 7c, the step of determining the plurality of fourth test values according to the second endpoint value of the first test interval, the second endpoint value of the second test interval, and the second scan speed may include: determining a quadratic curve of a fourth test interval changing along with the scanning time according to the second endpoint value of the first test interval, the second endpoint value of the second test interval and the second scanning speed; a plurality of fourth test values is determined based on a quadratic curve of the fourth test interval over the scan time.

In the above step, a quadratic curve form for smoothing the fourth test section may be established, for example, as shown in fig. 7c, the quadratic curve form for smoothing the fourth test section may be expressed as Y ═ b₂-m₂(x-a₂)²Wherein m is₂、a₂And b₂Is the unknown quantity to be determined. In the case shown in fig. 6a, the second endpoint value of the fourth test interval may be determined according to the second endpoint value of the first test interval, the first endpoint value of the fourth test interval may be determined according to the second endpoint value of the second test interval, and in order to achieve a smooth transition between the second test interval and the fourth test interval, the rate of change of the fourth test value at the intersection with the second test interval should be equal to the rate of change of the second test value at the intersection, and in the case shown in fig. 6a, the second test value changes at a constant speed, that is, the rate of change of the second test value at the intersection is a second scanning speed (that is, the slope K in fig. 7 c).

Therefore, the above-described quadratic curve expression Y can be determined as b₂-m₂(x-a₂)²The coordinates (0, V2') of the first end point of the fourth test interval, the coordinates (t4, V2) of the second end point of the third test interval, and the second scan speed K, so that a system of equations of three-way type can be established according to the three known quantities to determine m₂、a₂And b₂The value of (c). Here, t4 denotes a scan completion time of the fourth scan operation, which may be determined according to the entire time of the full-range scan operation, for example, may be such that (t4-t3) occupies 10% of the entire time of the full-range scan operation, but it is not limited theretoIn this regard, the smaller (t4-t3) the better, to allow the second scan operation to occupy more time throughout the full range of scan operations, so that the second scan speed may be as small as possible at a timing of the second test interval. As described above, in the case shown in fig. 7c, the second scanning speed K may be (V2 '-V1')/(t 3-t2), where (t3-t2) denotes a scanning time of the second scanning operation.

As an example, the quadratic curve expression Y ═ b in the fourth test interval₂-m₂(x-a₂)²The specific solving process of (2) is as follows:

the coordinates (0, V2') and (t4, V2) may be substituted into the quadratic curve expression Y ═ b, respectively₂-m₂(x-a₂)²The following expressions (5) and (6) are obtained:

V2′＝b₂-m₂(-a₂)² (5)

V2＝b₂-m₂(t4-a₂)² (6)

can be expressed in terms of a quadratic curve (Y ═ b)₂-m₂(x-a₂)²Derivation, the derivation expression can be expressed as the following formula (7):

Y′＝-2m₂(x-a₂) (7)

where Y' may be equal to the second scanning speed K, and thus, the above equation (7) may be expressed as:

K＝-2m₂(t2-a₂) (8)

in the above formulas (5), (6) and (8), V2, V2', t4 and K are known amounts, and therefore, it can be established as to m₂、a₂And b₂Ternary system of equations of unknown quantity to solve m according to mathematical method₂、a₂And b₂The value of (c).

In solving for m₂、a₂And b₂After the value of (a), the quadratic curve expression Y ═ b in the fourth test interval can be determined₂-m₂(x-a₂)²A plurality of fourth test values may thus be selected based on the expression.

As shown in fig. 7c, the test values of the full-range scan operation of the third, second, and fourth scan operations may be smoothly varied over time in order to operate a variable load to achieve a continuous scan operation.

Further, fig. 8 shows a scanning trend diagram during a full-range scanning operation. In fig. 8, the horizontal axis represents time (in ms), the left vertical axis represents voltage (in volt-ampere), and the right vertical axis represents velocity/acceleration, which are only shown to show the trend of the two, so that the right vertical axis can be a dimensionless normalized value. As shown in fig. 8, during the second scan operation, the variation amount of the second test value is close to 0, for example, when the second test value is a voltage V, dV/dt is 0, that is, the scan speed is 0. Therefore, the equivalent parallel capacitance effect of the photovoltaic cell can be overcome, and the maximum power of the photovoltaic cell can be accurately tested. Further, as shown in fig. 8, during the second scanning operation, the scanning acceleration of the voltage may be a constant value.

Fig. 9 shows a schematic diagram comparing test results of a scan control method of a photovoltaic cell according to an exemplary embodiment of the present application and a scan control method of a photovoltaic cell according to the related art. In fig. 9, the horizontal axis represents time, and the vertical axis represents the deviation of the IV curve obtained by the forward scanning and the reverse scanning. In the example of fig. 9, the photovoltaic cell to be tested is an IBC high-capacity solar cell module, the pulse width required by the conventional scanning method of the prior art is about 150ms to 250ms, and the pulse width required by the scanning method according to the embodiment of the present application is about 50ms to 70ms, and as can be seen from fig. 9, the deviation of the IV curve obtained by the forward scanning and the reverse scanning of the conventional scanning method is large and is greater than 2.50%, while the deviation of the IV curve obtained by the forward scanning and the reverse scanning of the scanning method according to the embodiment of the present application is much smaller than that of the conventional scanning method and can be less than 1.36%. Therefore, the test result of the scanning method according to the embodiment of the application is more accurate.

According to the scanning control method of the photovoltaic cell, the scanning operation can be performed twice, and the area where the maximum power point is located (namely, the second test interval) can be rapidly and preliminarily determined in the first scanning operation, so that the maximum power point can be determined specifically for each tested cell, and the maximum power of the photovoltaic cell can be accurately tested.

Although the various steps are labeled in the figures with reference numerals S1, S2, S3, etc., this reference numeral is merely for convenience of description, and the various steps of the present application may be performed out of the order shown or discussed, in a substantially simultaneous manner, or in a reverse order.

Another aspect of the present application provides a scanning control apparatus for a photovoltaic cell. Fig. 10 shows a schematic block diagram of a scanning control device of a photovoltaic cell according to an exemplary embodiment of the present application. As shown in fig. 10, the apparatus includes a first scanning unit 100, a first determining unit 200, an interval determining unit 300, a second scanning unit 400, and a second determining unit 500.

The first scanning unit 100 may determine a first test interval, perform a first scanning operation on the photovoltaic cell at a first scanning speed based on a plurality of first test values in the first test interval, and obtain a plurality of first power values of the photovoltaic cell corresponding to the plurality of first test values.

The first determination unit 200 may determine a first power maximum test value corresponding to a maximum power value among the plurality of first power values.

The interval determination unit 300 may determine the second test interval based on the first power maximum test value.

The second scanning unit 400 may perform a second scanning operation on the photovoltaic cell at a second scanning speed based on a plurality of second test values in a second test interval, to obtain a plurality of second power values of the photovoltaic cell corresponding to the plurality of second test values. Here, the second scanning speed is smaller than the first scanning speed.

The second determining unit 500 may determine a maximum power value among the plurality of second power values and a second power maximum test value corresponding to the maximum power value among the plurality of second power values.

The first scanning unit 100, the first determining unit 200, the interval determining unit 300, the second scanning unit 400, and the second determining unit 500 may execute corresponding steps in the method according to the method for controlling scanning of the photovoltaic cell in the method embodiment shown in fig. 1 to 9, for example, the steps may be implemented by machine readable instructions executable by the first scanning unit 100, the first determining unit 200, the interval determining unit 300, the second scanning unit 400, and the second determining unit 500, and specific implementation manners of the first scanning unit 100, the first determining unit 200, the interval determining unit 300, the second scanning unit 400, and the second determining unit 500 may refer to the above-described method embodiment, which is not described herein again.

Another aspect of the present application provides an electronic device that includes a processor and a memory. The memory stores a computer program. When the computer program is executed by the processor, the electronic device may perform the steps of the method for controlling scanning of a photovoltaic cell in the method embodiments shown in fig. 1 to fig. 9, and specific implementation manners may refer to the method embodiments, which are not described herein again.

Another aspect of the present application provides a computer-readable storage medium storing a computer program, which, when being executed by a processor, can perform the steps of the method for controlling scanning of a photovoltaic cell in the method embodiments shown in fig. 1 to 9.

According to the scanning control method and device for the photovoltaic cell and the electronic equipment, the accuracy of testing the maximum power point of the photovoltaic cell can be improved through two scanning operations with different scanning speeds.

In addition, according to the photovoltaic cell scanning control method, the photovoltaic cell scanning control device and the electronic equipment, the second test interval is determined based on the first power maximum test value and the offset, the scanning speed of the second scanning operation can be allowed to be slowed down, so that accurate testing can be realized under the condition that the pulse width of the light source is small, and the requirement for testing the light source is reduced.

In addition, according to the photovoltaic cell scanning control method, the photovoltaic cell scanning control device and the electronic equipment, the third test interval and the fourth test interval are determined according to the first test interval and the second test interval, so that full-range scanning operation is achieved, and therefore a complete volt-ampere characteristic curve of the photovoltaic cell is obtained.

In addition, according to the scanning control method and device for the photovoltaic cell and the electronic equipment, the change curve of the test value in the whole-range scanning operation process can be subjected to smoothing processing, so that the operation of an electronic device such as a variable load in the actual test process is facilitated.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. The above-described embodiments of the apparatus are merely illustrative, and for example, the division of the units is only one logical division, and there may be other divisions when actually implemented, and for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed coupling or direct coupling or communication connection between each other may be an indirect coupling or communication connection through some communication interfaces, devices or units, and may be electrical, mechanical or other forms.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a non-volatile computer-readable storage medium executable by a processor. Based on such understanding, the technical solutions of the present application or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the methods described in the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

Finally, it should be noted that: the above-mentioned embodiments are only specific embodiments of the present application, and are used to illustrate the technical solutions of the present application, but not to limit the technical solutions, and the scope of the present application is not limited to the above-mentioned embodiments, although the present application is described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: any person skilled in the art can modify or easily conceive the technical solutions described in the foregoing embodiments or equivalent substitutes for some technical features within the technical scope disclosed in the present application; such modifications, changes or substitutions do not depart from the spirit and scope of the exemplary embodiments of the present application, and are intended to be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A scanning control method of a photovoltaic cell is characterized by comprising the following steps:

determining a first test interval, and performing a first scanning operation on the photovoltaic cell at a first scanning speed based on a plurality of first test values in the first test interval to obtain a plurality of first power values of the photovoltaic cell corresponding to the plurality of first test values;

determining a first power maximum test value corresponding to a maximum power value of the plurality of first power values;

determining a second test interval based on the first maximum power test value;

performing a second scanning operation on the photovoltaic cell at a second scanning speed based on a plurality of second test values in the second test interval to obtain a plurality of second power values of the photovoltaic cell corresponding to the plurality of second test values, wherein the second scanning speed is less than the first scanning speed; the first scanning speed refers to a change rate of the first test value during the first scanning operation; the second scanning speed refers to a change rate of the second test value during the second scanning operation;

determining a maximum power value of the plurality of second power values and a second power maximum test value corresponding to a maximum power value of the plurality of second power values.

2. The method of claim 1, wherein determining a second test interval based on the first power max test value comprises:

determining a difference value between the first power maximum test value and a first offset as a first endpoint value of the second test interval;

determining a sum of the first power maximum test value and a second offset as a second endpoint value of the second test interval;

determining the second test interval based on a first endpoint value of the second test interval and a second endpoint value of the second test interval.

3. The method according to claim 2, wherein a first end value of the second test interval is greater than a first end value of the first test interval, and a second end value of the second test interval is less than a second end value of the first test interval.

4. The method for controlling the scanning of the photovoltaic cell according to claim 1, further comprising:

performing a third scanning operation on the photovoltaic cell based on a plurality of third test values in a third test interval;

performing a fourth scan operation on the photovoltaic cell based on a plurality of fourth test values in a fourth test interval,

wherein the third test interval is determined by:

determining a first endpoint value of a third test interval based on the first endpoint value of the first test interval; determining a second endpoint value for the third test interval based on the first endpoint value for the second test interval; determining the third test interval based on the first endpoint value and the second endpoint value of the third test interval,

wherein the fourth test interval is determined by:

determining a first endpoint value of the fourth test interval based on a second endpoint value of the second test interval; determining a second endpoint value of a fourth test interval based on the second endpoint value of the first test interval; determining the fourth test interval based on a first endpoint value and a second endpoint value of the fourth test interval.

5. The method for controlling the scanning of the photovoltaic cell according to claim 4, further comprising:

determining the plurality of third test values according to the first endpoint value of the first test interval, the first endpoint value of the second test interval and the second scanning speed;

determining the plurality of fourth test values according to the second endpoint value of the first test interval, the second endpoint value of the second test interval, and the second scan speed.

6. The method of claim 5, wherein determining the plurality of third test values according to the first endpoint value of the first test interval, the first endpoint value of the second test interval, and the second scan speed comprises:

determining a quadratic curve of the third test interval changing along with the scanning time according to the first endpoint value of the first test interval, the first endpoint value of the second test interval and the second scanning speed;

determining the plurality of third test values based on a quadratic curve of the third test interval over scan time,

determining the plurality of fourth test values according to the second endpoint value of the first test interval, the second endpoint value of the second test interval, and the second scan speed, including:

determining a quadratic curve of the fourth test interval changing along with the scanning time according to the second endpoint value of the first test interval, the second endpoint value of the second test interval and the second scanning speed;

determining the plurality of fourth test values based on a quadratic curve of the fourth test interval as a function of scan time.

7. The method according to claim 1, wherein the first scanning operation is a forward scanning or a reverse scanning, and the second scanning operation is a forward scanning.

8. A scanning control device of a photovoltaic cell is characterized by comprising:

the first scanning unit is used for determining a first test interval, and performing first scanning operation on the photovoltaic cell at a first scanning speed based on a plurality of first test values in the first test interval to obtain a plurality of first power values of the photovoltaic cell corresponding to the plurality of first test values;

a first determination unit that determines a first power maximum test value corresponding to a maximum power value among the plurality of first power values;

an interval determination unit which determines a second test interval based on the first maximum power test value;

the second scanning unit is used for carrying out second scanning operation on the photovoltaic cell at a second scanning speed based on a plurality of second test values in the second test interval to obtain a plurality of second power values of the photovoltaic cell corresponding to the plurality of second test values, wherein the second scanning speed is smaller than the first scanning speed;

the first scanning speed refers to a change rate of the first test value during the first scanning operation; the second scanning speed refers to the variation rate of the second test value in the second scanning operation process;

a second determination unit that determines a maximum power value of the plurality of second power values and a second power maximum test value corresponding to a maximum power value of the plurality of second power values.

9. An electronic device, characterized in that the electronic device comprises:

a processor;

memory storing a computer program which, when executed by the processor, implements a method of scan control of a photovoltaic cell according to any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that the computer program, when executed, implements a method of scan control of a photovoltaic cell according to any one of claims 1 to 7.