Virtual connection abnormity detection method and device, electronic equipment and storage medium

Abstract

The invention provides a virtual connection abnormity detection method and device, electronic equipment and a storage medium. The method comprises the following steps: acquiring first voltage values of at least two paths of direct current connected to an inverter; performing voltage stability detection on the first voltage value to obtain a first detection result; wherein the first detection result is used for indicating whether the voltage of the direct current meets a preset stability condition; if the first detection result indicates that the first detection result does not conform to the preset deviation condition, determining at least one pair of target direct current with the voltage relative deviation conforming to the preset deviation condition from the at least two paths of direct current; performing voltage synchronous change relation detection on each pair of target direct current to obtain a second detection result; and according to the second detection result, determining whether virtual connection abnormity exists in the inverter. By analyzing the voltage stability and the voltage synchronous change relation of each path of direct current of the inverter, the characteristics of the virtual connection abnormity of the inverter can be accurately extracted, so that the accuracy of virtual connection abnormity detection is improved.

Description

Technical Field

[0001] The present disclosure relates to the field of photovoltaic technology, and in particular to a method, device, electronic device and storage medium for detecting virtual connection anomalies. Background Art

[0002] The DC power lines connected to the inverter may have false connection abnormalities due to unstable connectors or sudden loss of components. Short-term false connection abnormalities may cause continued inefficiency of the power station and affect power generation, while long-term false connection abnormalities may cause component burning or even power station fire, posing a major safety hazard. Therefore, false connection abnormalities are an abnormality that requires key detection.

[0003] The related technology usually identifies the virtual connection abnormality based on the on-off status of the inverter. This method is prone to identification errors and has a technical problem of low accuracy. Summary of the invention

[0004] In view of this, an object of the present disclosure is to provide a method, device, electronic device and storage medium for detecting virtual connection anomalies, so as to improve the accuracy of virtual connection anomaly detection.

[0005] In a first aspect, an embodiment of the present disclosure provides a method for detecting a virtual connection abnormality, the method comprising: obtaining a first voltage value of at least two direct current power supplies connected to an inverter; wherein the first voltage value comprises a voltage value of the direct current power collected within a first specified time period; performing a voltage stability detection on the first voltage value to obtain a first detection result; wherein the first detection result is used to indicate whether the voltage of the direct current power meets a preset stability condition; if the first detection result indicates that it does not meet the requirements, determining at least one pair of target direct current power supplies whose relative voltage deviation meets a preset deviation condition from the at least two direct current power supplies; performing a voltage synchronization change relationship detection on each pair of target direct current power supplies to obtain a second detection result; and determining whether the inverter has a virtual connection abnormality based on the second detection result.

[0006] In a second aspect, an embodiment of the present disclosure provides a device for detecting a virtual connection abnormality, the device comprising: a data acquisition module, for acquiring a first voltage value of at least two direct currents connected to the inverter; wherein the first voltage value comprises the voltage value of the direct current collected within a first specified time period; a first detection module, for performing a voltage stability detection on the first voltage value to obtain a first detection result; wherein the first detection result is used to indicate whether the voltage of the direct current meets a preset stability condition; a deviation determination module, for determining at least one pair of target direct currents whose relative voltage deviation meets a preset deviation condition from the at least two direct currents if the first detection result indicates non-compliance; a second detection module, for performing a voltage synchronization change relationship detection on each pair of target direct currents to obtain a second detection result; and an abnormality determination module, for determining whether the inverter has a virtual connection abnormality based on the second detection result.

[0007] In a third aspect, an embodiment of the present disclosure provides an electronic device, including a processor and a memory, wherein the memory stores machine executable instructions that can be executed by the processor, and the processor executes the machine executable instructions to implement the above-mentioned virtual connection anomaly detection method.

[0008] In a fourth aspect, an embodiment of the present disclosure provides a computer-readable storage medium, which stores computer-executable instructions. When the computer-executable instructions are called and executed by a processor, the computer-executable instructions prompt the processor to implement the above-mentioned virtual connection anomaly detection method.

[0009] The embodiments of the present disclosure bring the following beneficial effects:

[0010] The above-mentioned detection method, device, electronic device and storage medium of virtual connection anomaly can accurately extract the characteristics of inverter virtual connection anomaly by analyzing the voltage stability and voltage synchronization change relationship of each DC power of the inverter, thereby improving the accuracy of virtual connection anomaly detection.

[0011] Other features and advantages of the present disclosure will be described in the following description, and partly become apparent from the description, or understood by practicing the present disclosure. The purpose and other advantages of the present disclosure are realized and obtained by the structures particularly pointed out in the description, claims and drawings.

[0012] In order to make the above-mentioned objectives, features and advantages of the present disclosure more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the specific embodiments of the present disclosure or the technical solutions in the prior art, the drawings required for use in the specific embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0014] Figure 1 It is a flow chart of an embodiment of a method for detecting virtual connection abnormality in an embodiment of the present disclosure;

[0015] Figure 2 A schematic diagram of a virtual connection abnormality detection device provided by an embodiment of the present disclosure;

[0016] Figure 3 A schematic diagram of an electronic device provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present disclosure.

[0018] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "including" or "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0019] For ease of understanding, the specific process of the embodiment of the present disclosure is described below. Figure 1 , an embodiment of the method for detecting virtual connection abnormality in the embodiment of the present disclosure includes:

[0020] Step S10, obtaining a first voltage value of at least two DC power lines connected to the inverter; wherein the first voltage value includes a voltage value of the DC power collected within a first specified time period;

[0021] It can be understood that the inverter can convert the DC power generated by the photovoltaic module into AC power. In one embodiment, the DC power input to the inverter can be divided into multiple paths, or the DC power can be divided into multiple paths and then input into the inverter. Each path of DC power can correspond to a part of the photovoltaic modules or battery packs in the photovoltaic power generation system.

[0022] For example, when multiple photovoltaic modules are connected in series to form a photovoltaic string, the DC power generated by one or more photovoltaic strings can be used as a DC power path and connected to an inverter to facilitate control and reduce coupling. In one embodiment, each DC power path can also correspond to a maximum power point tracking (MPPT) device to optimize the performance of each DC power path and improve the overall energy efficiency of the photovoltaic power generation system. Therefore, a DC power path can also be called an MPPT path, which is not specifically limited here.

[0023] In this embodiment, the voltage values ​​of at least two DC power lines connected to the inverter are collected according to the preset collection frequency, and the first voltage value includes the voltage value of each DC power line collected within the first specified time period, and the first specified time period may include multiple collection moments, and each DC power line corresponds to a voltage value at each collection moment. Among them, the first specified time period can be determined according to the preset abnormality detection frequency. For example, assuming that an abnormality detection is performed once a day, the first specified time period can be one day of the current detection cycle, which is not specifically limited here.

[0024] Step S20, performing a voltage stability test on the first voltage value to obtain a first test result; wherein the first test result is used to indicate whether the voltage of the direct current meets a preset stability condition;

[0025] In this embodiment, by detecting the voltage stability of the DC power through the first voltage value, the voltage instability can be screened out first, and then it can be further confirmed whether the voltage instability is caused by virtual connection. For the voltage stability, the virtual connection anomaly can be directly excluded, thereby improving the efficiency of abnormality detection. Specifically, if the first detection result indicates that the voltage of the DC power meets the preset stability condition, it is determined that there is no virtual connection anomaly in the inverter.

[0026] In one implementation, by performing data distribution analysis on the first voltage value, a voltage stability detection result, i.e., a first detection result, can be obtained. Specifically, a variety of data distribution indicators can be used for data distribution analysis, such as standard deviation, root mean square (RMS), differential value, etc., which are not specifically limited here.

[0027] As an example but not limitation, by performing differential value calculation on the first voltage value of each DC power, a target differential value corresponding to each DC power is obtained, and according to the target differential value, it is determined whether the voltage of the DC power meets the preset stability condition to obtain the first detection result. Specifically, in one embodiment, if the target differential value is greater than a preset differential threshold or belongs to a preset differential interval, it is determined that the voltage of the DC power meets the preset stability condition, otherwise, it is determined that the voltage of the DC power does not meet the preset stability condition.

[0028] In one embodiment, the voltage average value and extreme value of each DC power within the first specified time period and other indicators for measuring the data fluctuation range may also be calculated, and based on the one or more indicators for measuring the data fluctuation range, it is determined whether the voltage of the DC power meets the preset stability condition to obtain the first detection result. Specifically, in one embodiment, if the difference between the extreme value and the average value is greater than the preset difference threshold, it is determined that the voltage of the DC power does not meet the preset stability condition, otherwise, the voltage of the DC power meets the preset stability condition.

[0029] In one implementation, a change curve of the first voltage value may be plotted, and whether the voltage of the DC power meets the preset stability condition may be determined based on the volatility of the change curve to obtain a first detection result. Specifically, the voltage stability analysis of the change curve may be performed using an artificial intelligence model to obtain the first detection result, which will not be described in detail herein.

[0030] Step S30: if the first detection result indicates non-compliance, determining at least one pair of target direct currents whose relative voltage deviations meet a preset deviation condition from at least two direct currents;

[0031] In this embodiment, if the first detection result indicates that the voltage of the DC power does not meet the preset stability conditions, it is determined whether there is at least one pair of target DC power in the at least two DC power lines whose relative voltage deviation meets the preset deviation conditions. If not, it can be directly determined that there is no virtual connection abnormality in the inverter. If so, the subsequent steps are performed.

[0032] In this embodiment, by judging whether the relative voltage deviation between each two of at least two DC currents meets the preset deviation condition, at least one pair of target DC currents is obtained. For example, the three DC currents connected to the inverter are DC 1, DC 2 and DC 3. Then, the relative voltage deviation between each two of the three DC currents includes: the relative voltage deviation between DC 1 and DC 2, DC 1 and DC 3, and DC 2 and DC 3. Assuming that the relative voltage deviation between DC 1 and DC 2 meets the preset deviation condition, DC 1 and DC 2 are a pair of target DC currents, and subsequent voltage synchronization change relationship detection is performed. The specific details are not limited here.

[0033] In one embodiment, the relative voltage deviation between each two of the at least two direct currents can be determined by the mean and / or quantile of the first voltage value of each direct current. Specifically, the first voltage value of each direct current can be subjected to the mean and quantile technology to obtain the first mean and first quantile corresponding to each direct current, and then, based on the first mean and first quantile corresponding to each direct current, it is judged whether the relative voltage deviation between the direct currents meets the preset deviation condition, thereby determining at least one pair of target direct currents, or determining that there is no virtual connection abnormality in the inverter.

[0034] Further, when judging whether the relative voltage deviation between the direct currents meets the preset deviation condition according to the first mean and the first quantile corresponding to each direct current, the difference of the first mean and the first quantile between the direct currents can be calculated first, and the first mean difference and the first quantile difference corresponding to the plurality of pairs of direct currents are obtained, and then the direct current pairs whose first mean difference is greater than the preset mean difference threshold and the first quantile difference is greater than the preset quantile threshold are determined as the target direct current pairs, thereby obtaining at least one pair of target direct currents. If there is no direct current pair whose first mean difference is greater than the preset mean difference threshold and the first quantile difference is greater than the preset quantile threshold, it is determined that there is no virtual connection abnormality in the inverter.

[0035] Step S40, performing voltage synchronous change relationship detection on each pair of target direct currents to obtain a second detection result;

[0036] In this embodiment, if the first detection result is used to indicate that the voltage of the DC power does not meet the preset stability condition, the synchronous change relationship of the voltage is detected for each pair of target DC power to obtain a second detection result. In one embodiment, the voltage synchronous change relationship is used to indicate whether the voltage change between the same DC power or different DC power is consistent and dynamic. If it is consistent and dynamic, it can be determined that the inverter has a virtual connection abnormality. Otherwise, it can be determined that the inverter does not have a virtual connection abnormality. The virtual connection abnormality of the inverter can be more accurately identified by detecting the voltage synchronous change relationship.

[0037] In one embodiment, a change curve of the first voltage value of each pair of target direct currents can be drawn, and a voltage synchronous change relationship detection can be performed based on the change curve to obtain a second detection result; based on the first voltage value of each pair of target direct currents, a mean change curve, a maximum change curve, or a minimum change curve, etc. of the voltage in multiple time windows can be drawn, and then a voltage synchronous change relationship detection can be performed based on the drawn change curve to obtain a second detection result, which will not be described in detail here.

[0038] In one embodiment, the voltage synchronization change relationship of each pair of target direct currents can also be detected through a preset correlation analysis algorithm to obtain a second detection result, wherein the correlation analysis algorithm can be an information entropy analysis algorithm such as entropy, conditional entropy, relative entropy, or a mutual information algorithm such as mutual information, conditional mutual information, relative mutual information, or any other algorithm that can be used for correlation analysis, which will not be described in detail here.

[0039] Step S50: Determine whether there is a virtual connection abnormality in the inverter according to the second detection result.

[0040] In one implementation, if the second detection result indicates that any pair of target direct currents has a voltage synchronous change relationship, it is determined that the inverter has a virtual connection abnormality, and if the second detection result indicates that each pair of target direct currents has a voltage synchronous change relationship, it is determined that the inverter does not have a virtual connection abnormality. Further, it is also possible to determine that one of the target direct currents in the target direct current pair having a voltage synchronous change relationship is a direct current having a virtual connection abnormality, and the details are not repeated here.

[0041] The method for detecting virtual connection anomaly provided in the above implementation can accurately extract the characteristics of the inverter virtual connection anomaly by analyzing the voltage stability and voltage synchronization change relationship of each DC power of the inverter, thereby improving the accuracy of virtual connection anomaly detection.

[0042] Next, the method of detecting voltage stability will be described in detail.

[0043] In one embodiment, the first voltage value includes multiple values; a voltage stability test is performed on the first voltage value, and when a first test result is obtained, a mean and quantile are calculated for the first voltage value of each direct current to obtain a first mean and a first quantile corresponding to each direct current; a mean and a quantile are calculated for the first voltage values ​​corresponding to multiple time windows within a first specified time period to obtain a second mean and a second quantile of each direct current in each time window; based on the first mean, the second mean, the first quantile and the second quantile, target binary trees of means and quantiles are respectively constructed; based on the target binary tree, it is determined whether the voltage of the direct current meets a preset stability condition to obtain a first test result.

[0044] In this implementation, firstly, the overall voltage mean (i.e., the first mean) and the overall voltage quantile (i.e., the first quantile) of each direct current within a certain time length, as well as the local voltage mean (i.e., the second mean) and the local voltage quantile (i.e., the second quantile) of each direct current in a certain time window within the time length are calculated, and then, based on the above-mentioned first mean, first quantile, second mean and second quantile, a target binary tree of the mean and a target binary tree of the quantile are constructed respectively, wherein the target binary tree can be used to measure the stability of the voltage, and according to the target binary tree, it can be determined whether the voltage of the direct current meets the preset stability condition, thereby obtaining the first detection result.

[0045] In this implementation, by comprehensively considering the overall voltage fluctuation of direct current within a period of time and the local voltage fluctuation within a time window, the relativity of the local voltage fluctuation and the overall voltage fluctuation can be observed more accurately. The binary tree is also a form that can be used to represent data structures. The voltage distribution can be discovered through the binary tree, thereby more accurately detecting voltage stability and further more accurately identifying virtual connection anomalies.

[0046] In one embodiment, when constructing a target binary tree of means, a target binary tree corresponding to each DC current can be constructed, or all first means and second means can be integrated into one binary tree, which is not specifically described here. When constructing a target binary tree corresponding to each DC current, for each DC current, the first mean of the DC current can be used as the root node of the initial binary tree, and the second mean of the DC current in each time window can be recursively inserted into the initial binary tree, thereby obtaining the target binary tree corresponding to the DC current.

[0047] In addition, if all the first means and second means are integrated into a binary tree, a maximum value can be first determined from all the first means and second means, and the maximum value is used as the root node of the initial binary tree, and then the remaining first means and second means are recursively inserted into the binary tree in turn, so as to obtain the target binary tree of the mean. It should be noted that the construction method of the target binary tree of quantiles is the same as that of the target binary tree of means, which will not be repeated here.

[0048] In one embodiment, when constructing target binary trees of mean and quantile respectively based on the first mean, the second mean, the first quantile and the second quantile, target binary trees of mean and quantile respectively can be constructed according to the maximum mean and the maximum quantile, wherein the maximum mean includes the maximum first mean and the maximum second mean of each time window, and the maximum quantile includes the maximum first quantile and the maximum second quantile of each time window. The maximum mean and the maximum quantile of the voltage can more accurately measure the stability of the voltage, and thus more accurately identify the virtual connection anomaly.

[0049] It should be noted that the probability distribution range of a random variable is divided into several equal numerical points, and these numerical points are quantiles. Commonly used quantiles include median (i.e., 2 quantiles), quartiles, deciles, percentiles, etc. In this implementation, when calculating quantiles, the first N and last N quantiles of any multiple quantiles can be calculated, where N is an integer greater than or equal to 1.

[0050] For example, any multi-quantile can be a quartile. When calculating the quantile, the first and third quantiles in the quartile can be calculated, that is, the case where N=1. If any multi-quantile is a decil, when calculating the quantile, the first and ninth quantiles in the decil can be calculated, also the case where N=1. The first, second, eighth and ninth quantiles in the decil can also be calculated, that is, the case where N=2. There is no specific limitation here.

[0051] It is understandable that by calculating at least one quantile before and after, the influence of abnormal values ​​that are too large or too small on voltage stability detection can be more accurately shielded, interference items can be more effectively shielded, missed reports can be reduced, and the accuracy of virtual connection abnormality detection can be improved.

[0052] In one embodiment, the quantiles include the first quartile and the third quartile. That is, when calculating the quantiles, the first quartile and the third quartile are calculated, that is, the 25% quantile and the 75% quantile, and the obtained first quartile includes the quantiles corresponding to the first quartile and the third quartile respectively. Similarly, the obtained second quartile also includes the quantiles corresponding to the first quartile and the third quartile respectively. When constructing the target binary tree of quantiles, the target binary trees corresponding to the first quartile and the third quartile can be constructed, or the target binary tree common to the first quartile and the third quartile can be constructed, and the specifics are not limited here.

[0053] In one embodiment, when determining whether the voltage of the direct current meets the preset stability condition based on the target binary tree and obtaining the first detection result, it is possible to determine whether the voltage of the direct current meets the preset stability condition based on the height of the target binary tree and / or the height difference between the target binary trees to obtain the first detection result. Specifically, if the height of the target binary tree and / or the height difference between the target binary trees meet the preset stability condition, it is determined that the voltage of the direct current meets the preset stability condition; otherwise, it is determined that the voltage of the direct current does not meet the preset stability condition, and the first detection result is obtained.

[0054] Furthermore, in one embodiment, when constructing target binary trees of means and quantiles based on the first mean, the second mean, the first quantile and the second quantile, respectively, the difference in the first mean between the direct currents and the difference in the first quantile between the direct currents are calculated according to the first mean and the first quantile corresponding to each direct current, to obtain multiple first mean difference values ​​and multiple first quantile differences; the difference in the second mean between the direct currents and the difference in the second quantile between the direct currents in each time window are calculated according to the second mean and the second quantile of each direct current in each time window, to obtain multiple second mean difference values ​​and multiple second quantile differences corresponding to each time window; the target binary trees of means and quantiles are constructed according to the multiple first mean difference values, the multiple first quantile differences, and the multiple second mean difference values ​​and the multiple second quantile differences corresponding to each time window.

[0055] In this implementation, first, based on the overall voltage mean and overall voltage quantile of each DC power, the overall voltage mean difference (i.e., the first mean difference) and the overall quantile mean difference (i.e., the first quantile difference) between each DC power are calculated, and then based on the local voltage mean and local voltage quantile of each DC power within a certain time window, the local voltage mean difference (i.e., the second mean difference) and the local quantile difference (i.e., the second quantile difference) of each DC power in each time window are calculated, and finally, based on these differences, the target binary tree of the mean and the target binary tree of the quantile are constructed respectively.

[0056] It can be understood that since voltage stability is relative, this embodiment constructs a target binary tree through the voltage deviation between each DC power line, so that the target binary tree can reflect the voltage deviation between different DC powers, thereby obtaining a first detection result indicating that the voltage is relatively unstable or relatively stable, making the detection of voltage stability more accurate, and thus making the detection of false connection anomalies more accurate.

[0057] In one embodiment, multiple first mean difference values, multiple first quantile difference values, and multiple second mean difference values ​​and multiple second quantile difference values ​​corresponding to each time window can be directly used as nodes of the binary tree to construct a target binary tree, or the maximum / minimum first mean difference value, the maximum / minimum first quantile difference value, and the maximum / minimum second mean difference value and the maximum / minimum second quantile difference value corresponding to each time window can be used as nodes of the binary tree to construct a target binary tree, and the specifics are not limited here.

[0058] In which, when calculating the difference in the first quantiles between the direct currents, it includes calculating the difference in the first quartile and the difference in the third quartile in the first quartile between the direct currents, and obtaining multiple first quartile differences, and the first quartile differences include the quantile differences corresponding to the first quartile and the third quartile respectively.

[0059] In one embodiment, when constructing target binary trees for means and quantiles respectively based on multiple first mean difference values, multiple first quantile difference values, and multiple second mean difference values ​​and multiple second quantile difference values ​​corresponding to each time window, the maximum difference value is used as the root node of the binary tree, and the difference residual value is used as the child node of the root node by comparing the difference residual value with the root node to obtain a basic binary tree; wherein the maximum difference value is the maximum value of the maximum first mean difference value and the maximum first quantile difference, and the difference residual value is the value of the maximum first mean difference value and the maximum first quantile difference except the maximum difference value; the maximum second mean difference value corresponding to each time window is recursively inserted into the basic binary tree to obtain a target binary tree for the mean; the maximum second quantile difference corresponding to each time window is recursively inserted into the basic binary tree to obtain a target binary tree for the quantile.

[0060] In this implementation, a basic binary tree is constructed with the maximum value of the overall voltage mean difference between the direct currents (i.e., the maximum first mean difference) and the maximum value of the overall voltage quantile difference (i.e., the maximum first quantile difference) as nodes of the basic binary tree, wherein the maximum first quantile difference includes the maximum quantile differences corresponding to the first quartile and the third quartile, respectively.

[0061] Next, based on the basic binary tree, target binary trees for means and quantiles are constructed respectively. Specifically, the maximum second mean difference value corresponding to each time window is recursively inserted into the basic binary tree, and the maximum second quantile difference value corresponding to each time window is recursively inserted into the basic binary tree.

[0062] In one embodiment, when the maximum second mean difference value corresponding to each time window is recursively inserted into the basic binary tree, the maximum second mean difference value corresponding to each time window can be compared with the current node in turn. If the current maximum second mean difference value is greater than a certain threshold value of the current node, it is determined whether there is a right node for the current node. If so, the right node is used as the current node, and the current maximum second mean difference value is continued to be compared with the current node. If not, the current maximum second mean difference value is inserted as the right node. If the current maximum second mean difference value is less than a certain threshold value of the current node, it is determined whether there is a left node for the current node. If so, the left node is used as the current node, and the current maximum second mean difference value is continued to be compared with the current node. If not, the current maximum second mean difference value is inserted as the left node.

[0063] Through the above recursive insertion process, the target binary tree of the mean can be obtained. Similarly, when the maximum second quantile difference corresponding to each time window is recursively inserted into the basic binary tree, it is also achieved through the above recursive insertion process, and the details are not repeated here. It should be noted that the above left node and right node can be interchangeable and do not constitute a specific limitation.

[0064] After obtaining the target binary tree, in one embodiment, based on the target binary tree, it is determined whether the voltage of the direct current meets the preset stability condition. When the first detection result is obtained, it is determined whether the height of the target binary tree is greater than the preset height threshold, and whether the height difference between the target binary tree of the mean and the target binary tree of the quantile is within the preset height difference range; if the heights of the target binary trees are all less than the preset height threshold, and the height difference between the target binary tree of the mean and the target binary tree of the quantile is within the preset height difference range, then a first detection result indicating that the voltage of the direct current does not meet the preset stability condition is obtained; if the height of any target binary tree is greater than or equal to the preset height threshold, and / or the height difference between the target binary tree of the mean and the target binary tree of the quantile exceeds the preset height difference range, then a first detection result indicating that the voltage of the direct current meets the preset stability condition is obtained.

[0065] It can be understood that the height of the target binary tree and the height difference between different target binary trees can reflect whether the voltage of each DC power is stable and whether the voltage deviation between each DC power is stable. In this embodiment, by judging whether the height of the target binary trees is less than the preset height threshold and whether the height difference between the target binary trees is within the preset height difference range, if the height of the target binary trees is less than the preset height threshold and the height difference between the target binary trees is within the preset height difference range, it means that the voltage of each DC power is unstable, and a first detection result indicating that the voltage of the DC power does not meet the preset stability condition is obtained. Conversely, if the height of any target binary tree is greater than or equal to the preset height threshold, and / or the height difference between the target binary trees exceeds the preset height difference range, it means that the voltage between each DC power is stable, and a first detection result indicating that the voltage of the DC power meets the preset stability condition is obtained.

[0066] Next, the detection of the voltage synchronous change relationship will be described in detail.

[0067] In one embodiment, if the first detection result indicates non-compliance, when determining at least one pair of target direct currents whose relative voltage deviation meets the preset deviation condition from at least two direct currents, the difference in the second means between the direct currents in each time window and the difference in the second quantiles between the direct currents are calculated based on the second means and second quantiles of the direct currents in each time window to obtain multiple second mean differences and multiple second quantile differences corresponding to each time window; a direct current pair corresponding to the maximum value among the multiple second mean differences and multiple second quantile differences is used as the target direct current; or, a direct current pair greater than a preset threshold among the multiple second mean differences and multiple second quantile differences is used as the target direct current; or, a direct current pair corresponding to a previously set number of values ​​in a difference sequence is used as the target direct current; wherein the difference sequence includes multiple second mean differences and multiple second quantile differences arranged in descending order.

[0068] It is understandable that by screening the target DC power pairs that meet the preset deviation conditions, the voltage synchronization change relationship detection can be performed on the specified DC power in a more targeted manner, thereby improving the detection efficiency of the virtual connection anomaly.

[0069] In this implementation, according to the difference between the second means and the second quantiles of the direct currents in each time window, at least one pair of target direct currents can be determined in three ways, and these three ways are described below. First, the difference between the second means of the direct currents in each time window is calculated to obtain multiple second mean differences corresponding to each time window, and the difference between the second quantiles of the direct currents in each time window is calculated to obtain multiple second quantile differences corresponding to each time window.

[0070] For ease of understanding, assume that there are three DC power lines connected to the inverter, namely DC 1, DC 2 and DC 3, and there are three time windows, namely time window 1, time window 2 and time window 3. Then, according to the second means and second quantiles of the three DC power lines in the three time windows, the difference between the second means and the second quantiles of the three DC power lines in the three time windows can be calculated to obtain the three second mean differences and the three second quantile differences corresponding to the three time windows. Among them, time window 1 corresponds to the second mean difference and the second quantile difference between DC 1 and DC 2, the second mean difference and the second quantile difference between DC 1 and DC 3, and the second mean difference and the second quantile difference between DC 2 and DC 3. Similarly, time window 2 and time window 3 also contain the second mean difference and the second quantile difference between the three DC power lines.

[0071] In the first method, a pair of DC currents corresponding to the maximum value among all the second mean differences and all the second quantile differences are taken as the target DC current. For example, assuming that among the total of 9 second mean differences and 9 second quantile differences corresponding to the above-mentioned 3 time windows, the second mean difference between DC current 1 and DC current 2 corresponding to time window 2 is the largest, then DC current 1 and DC current 2 are taken as the target DC currents for subsequent voltage synchronization change relationship detection.

[0072] In the second method, the DC pairs among all the second mean differences and all the second quantile differences that are greater than a preset threshold are taken as target DC, wherein the preset threshold may include a preset mean difference threshold corresponding to the second mean difference and a preset quantile difference threshold of the second quantile difference voltage; for example, assuming that among the total of 9 second mean differences and 9 second quantile differences corresponding to the above-mentioned 3 time windows, the second mean difference between DC 1 and DC 2 corresponding to time window 2 is greater than the preset mean difference threshold, the second quantile difference between DC 1 and DC 3 corresponding to time window 3 is greater than the preset quantile difference threshold, and the remaining second mean differences and second quantile differences are all less than or equal to the corresponding preset thresholds, then DC 1 and DC 2 are a pair of target DC, and DC 1 and DC 3 are another pair of target DC, and the specific details are not limited here.

[0073] In the third method, all the second mean differences and all the second quantile differences are first sorted in descending order, and after obtaining the difference sequence, the DC pairs corresponding to the first N values ​​in the difference sequence are taken as the target DC, where N is equal to the set number. For example, assuming that N=3, in the difference sequence obtained after sorting the total of 9 second mean differences and 9 second quantile differences corresponding to the above 3 time windows, the second mean difference between DC 1 and DC 2 corresponding to time window 2, the second quantile difference between DC 1 and DC 3 corresponding to time window 3, and the second mean difference between DC 2 and DC 3 corresponding to time window 1 are the first 3 in the difference sequence, then DC 1 and DC 2 are a pair of target DC, DC 1 and DC 3 are a pair of target DC, and DC 2 and DC 3 are also a pair of target DC, and the specific details are not limited here.

[0074] In one embodiment, when determining at least one pair of target direct currents whose relative voltage deviation meets a preset deviation condition from at least two direct currents, the difference in the second means between the direct currents in each time window and the difference in the second quantiles between the direct currents can be calculated based on the second means and second quantiles of the direct currents in each time window, so as to obtain the second mean difference and second quantile difference corresponding to multiple pairs of direct currents in each time window; then, the maximum second mean difference in each time window is compared with a preset mean difference threshold, and the maximum second quantile difference in each time window is compared with a preset quantile threshold, and the direct current pairs whose maximum second mean difference is greater than the preset mean difference threshold, or whose maximum second quantile difference is greater than the preset quantile threshold are counted, thereby obtaining at least one pair of first direct currents, and the statistical number of the same pair of first direct currents.

[0075] For example, assuming that there are three DC power lines connected to the inverter, namely DC 1, DC 2 and DC 3, and there are three time windows, namely time window 1, time window 2 and time window 3, then, based on the second means and second quantiles of the three DC power lines in the three time windows, the difference in the second means and the difference in the second quantiles between the three DC power lines in the three time windows can be calculated, wherein time window 1 includes the second mean difference and the second quantile difference between DC 1 and DC 2, the second mean difference and the second quantile difference between DC 1 and DC 3, and the second mean difference and the second quantile difference between DC 2 and DC 3. Similarly, time window 2 and time window 3 also include the second mean difference and the second quantile difference between the three DC power lines.

[0076] Based on this, each time window corresponds to a maximum second mean difference and a maximum second quantile difference. For example, the maximum second mean difference corresponding to time window 1 may be the second mean difference between DC 1 and DC 2, and the corresponding maximum second quantile difference may be the second quantile difference between DC 1 and DC 3. Similarly, the other two time windows also correspond to a maximum second mean difference and a maximum second quantile difference, respectively.

[0077] Assuming that the maximum second mean difference value corresponding to time window 1 is greater than the preset mean difference threshold, that is, the second mean difference value between DC 1 and DC 2 is greater than the preset mean difference threshold, then DC 1 and DC 2 can be regarded as a pair of first DCs, and the statistical number of this pair of first DCs is 1; assuming that the maximum second quantile difference value corresponding to time window 1 is also greater than the preset quantile threshold, that is, the second quantile difference value between DC 1 and DC 3 is greater than the preset mean difference threshold, then DC 1 and DC 3 can also be regarded as a pair of first DCs, and the statistical number of this pair of first DCs is also 1; assuming that the maximum second mean difference value corresponding to time window 2 is also the second mean difference value between DC 1 and DC 2, and the maximum second mean difference value corresponding to time window 2 is greater than the preset mean difference threshold, then DC 1 and DC 2 are once again regarded as a pair of first DCs, and the statistical number of this pair of first DCs is 2, and so on, until all time windows are counted, and at least one pair of first DCs and the statistical number of the same pair of first DCs are obtained.

[0078] Next, if the statistical number of a pair of first direct currents is greater than a preset number threshold, the pair of first direct currents is determined as a target direct current pair whose voltage relative deviation meets the preset deviation condition, thereby obtaining at least one pair of target direct currents. For example, assuming that the preset number threshold is 1, then in the above example, the statistical number of direct current 1 and direct current 2 as a pair of first direct currents is 2. Since 2>1, direct current 1 and direct current 2 can be used as a pair of target direct currents for subsequent voltage synchronization change relationship detection.

[0079] In one embodiment, a voltage synchronous change relationship detection is performed on each pair of target direct currents, and when a second detection result is obtained, the voltage change rate of the two target direct currents within a plurality of preset time lengths is calculated based on the first voltage value of each pair of target direct currents; based on the voltage change rate, the mutual information between the voltage change rates of each pair of target direct currents is calculated; based on the mutual information, it is determined whether there is a synchronous change relationship between the voltages of each pair of target direct currents, and the second detection result is obtained.

[0080] It can be understood that mutual information can be used to measure the degree of mutual dependence between two random variables. In this embodiment, by calculating the voltage change rate of each pair of target DC power in different time lengths, and then calculating the mutual information between the voltage change rates of each pair of target DC power, the mutual information can be used to measure the degree of mutual dependence between the voltage change rates of each pair of target DC power, that is, the synchronous change relationship. The higher the mutual information, the more synchronous the voltage change of a pair of target DC power and the tighter the synchronous change relationship, and vice versa.

[0081] In one embodiment, based on the voltage change rate, when calculating the mutual information between the voltage change rates of each pair of target direct currents, multiple average voltage change rate intervals are divided according to the maximum and minimum values ​​of the voltage change rate; based on the voltage change rate of the target direct current within multiple preset time lengths, a first probability that the voltage change rate of the target direct current belongs to each voltage change rate interval and a second probability that the voltage change rate of the target direct current within the same preset time length belongs to the same voltage change rate interval are calculated; based on the first probability and the second probability, the mutual information between the voltage change rates of each pair of target direct currents is calculated.

[0082] It can be understood that the mutual information between the voltage change rates of a pair of target direct currents can be used to indicate the closeness of the voltage change rates of a pair of target direct currents being simultaneously in the same voltage change interval. Therefore, in this embodiment, first, according to the maximum and minimum values ​​of the voltage change rate, a plurality of voltage change rate intervals covering the range from the minimum value to the maximum value are evenly divided. For example, assuming that the maximum value of the voltage change rate is 20 and the minimum value is 5, then [5, 20] can be evenly divided into a plurality of voltage change rate intervals. For example, assuming that it is divided into 2 voltage change rate intervals, the plurality of divided voltage change rate intervals can include [5, 10] and (10, 20], which are not specifically limited here.

[0083] Next, the first probability that each voltage change rate is in each voltage change rate interval is calculated, and then the second probability that the voltage change rate belongs to the same voltage change rate interval within the same preset time length is calculated. Finally, based on the first probability and the second probability, the mutual information between the voltage change rates of each pair of target direct currents is calculated, so that the mutual information can accurately measure the probability that a pair of target direct currents change at the same time and with a similar degree of change, thereby improving the accuracy of virtual connection anomaly detection.

[0084] For ease of understanding, let the number of voltage change rate intervals be n, and a pair of target DC lines are A and B. By statistics, the number of voltage change rates of A line in multiple preset time lengths belonging to the i-th voltage change rate interval is CA. i Among the voltage change rates of circuit B within multiple preset time lengths, the number of voltage change rates belonging to the i-th voltage change rate interval is CB i The number of voltage change rates of A and B that belong to the ith voltage change rate interval within the same preset time length is CAB i , the total number of preset time lengths is M. Then, the first probability P(A) that the voltage change rate of line A is in the i-th voltage change rate interval is i )for:

[0085]

[0086] The first probability P(B) that the voltage change rate of B is in the i-th voltage change rate interval i )for:

[0087]

[0088] The second probability P(AB) of the voltage change rate of A and B in the same preset time length belongs to the same voltage change rate interval i )for:

[0089]

[0090] According to the first probability and the second probability, the mutual information I(A,B) between the voltage change rates of the A and B paths is calculated by the mutual information formula:

[0091]

[0092] In one embodiment, when determining whether the inverter has a virtual connection abnormality based on the second detection result, if the second detection result indicates that the mutual information between the voltage change rates of any pair of target direct currents is greater than a preset mutual information threshold, it is determined that the inverter has a virtual connection abnormality. It is understandable that, assuming that the preset mutual information threshold is N, if I(A, B)>N, it is determined that the inverter has a virtual connection abnormality. Furthermore, based on the first mean value corresponding to the target direct current, a target direct current corresponding to the minimum first mean value can be determined as a direct current having a virtual connection abnormality.

[0093] It can be understood that, in one embodiment, before obtaining the first voltage value of at least two DC power paths connected to the inverter, the first current values ​​of multiple DC input paths of the inverter within a second specified time period can also be obtained; if the first current value of any DC input path meets the preset access conditions, it is determined that the DC power input by the corresponding DC input path is a DC power path connected to the inverter.

[0094] In this embodiment, the average current value of each DC input path within a certain time period can be calculated through the current values ​​of multiple DC input paths of the inverter, and the maximum number of times the same current value appears can be counted. If the average current value of any DC input path is greater than the preset current threshold, and the maximum number of times is less than the preset number threshold, it is determined that the DC input path meets the preset access condition, and the DC input by the DC input path is a DC power path connected to the inverter. In one embodiment, when the number of DC power paths connected to the inverter is greater than or equal to 2, the first voltage value of at least two DC power paths connected to the inverter is obtained.

[0095] Corresponding to the above method embodiment, see Figure 2A schematic diagram of a detection device for a virtual connection abnormality is shown, the device comprising: a data acquisition module 201, used to obtain a first voltage value of at least two direct currents connected to an inverter; wherein the first voltage value includes the voltage value of the direct current collected within a first specified time period; a first detection module 202, used to perform a voltage stability detection on the first voltage value to obtain a first detection result; wherein the first detection result is used to indicate whether the voltage of the direct current meets a preset stability condition; a deviation determination module 203, used to determine at least one pair of target direct currents whose relative voltage deviation meets a preset deviation condition from the at least two direct currents if the first detection result indicates that it does not meet the condition; a second detection module 204, used to perform a voltage synchronization change relationship detection on each pair of target direct currents to obtain a second detection result; an abnormality determination module 205, used to determine whether the inverter has a virtual connection abnormality based on the second detection result.

[0096] The above-mentioned virtual connection abnormality detection device can accurately extract the characteristics of the inverter virtual connection abnormality by analyzing the voltage stability and voltage synchronous change relationship of each DC power of the inverter, thereby improving the accuracy of virtual connection abnormality detection.

[0097] Optionally, the first voltage value includes multiple values; the above-mentioned first detection module 202 includes: a first calculation submodule, used to calculate the mean and quantile of the first voltage value of each direct current, and obtain the first mean and first quantile corresponding to each direct current; a second calculation submodule, used to calculate the mean and quantile of the first voltage values ​​corresponding to multiple time windows within the first specified time period, and obtain the second mean and second quantile of each direct current in each time window; a construction submodule, used to construct a target binary tree of means and quantiles based on the first mean, the second mean, the first quantile and the second quantile respectively; a first determination submodule, used to determine whether the voltage of the direct current meets the preset stability condition according to the target binary tree, and obtain a first detection result.

[0098] Optionally, the above-mentioned construction submodule includes: a first calculation unit, used to calculate the difference of the first mean values ​​between each direct current and the difference of the first quantiles between each direct current according to the first mean values ​​and the first quantiles corresponding to each direct current, so as to obtain multiple first mean difference values ​​and multiple first quantile differences; a second calculation unit, used to calculate the difference of the second mean values ​​between each direct current in each time window and the difference of the second quantiles between each direct current according to the second mean values ​​and the second quantiles of each direct current in each time window, so as to obtain multiple second mean difference values ​​and multiple second quantile differences corresponding to each time window; a construction unit, used to construct target binary trees of means and quantiles respectively according to the multiple first mean difference values, the multiple first quantile differences, and the multiple second mean difference values ​​and multiple second quantile differences corresponding to each time window.

[0099] Optionally, the above-mentioned construction unit is specifically used to: take the maximum difference value as the root node of the binary tree, compare the difference residual value with the root node, and use the difference residual value as the child node of the root node to obtain a basic binary tree; wherein the maximum difference value is the maximum value of the maximum first mean difference value and the maximum first quantile difference value, and the difference residual value is the value of the maximum first mean difference value and the maximum first quantile difference value other than the maximum difference value; recursively insert the maximum second mean difference value corresponding to each time window into the basic binary tree to obtain a target binary tree of the mean; recursively insert the maximum second quantile difference corresponding to each time window into the basic binary tree to obtain a target binary tree of the quantile.

[0100] Optionally, the above-mentioned first determination submodule is specifically used to: determine whether the height of the target binary tree is greater than a preset height threshold, and whether the height difference between the target binary tree of the mean and the target binary tree of the quantile is within a preset height difference range; if the heights of the target binary trees are all less than the preset height threshold, and the height difference between the target binary tree of the mean and the target binary tree of the quantile is within a preset height difference range, then a first detection result indicating that the voltage of the direct current does not meet the preset stability condition is obtained; if the height of any target binary tree is greater than or equal to the preset height threshold, and / or the height difference between the target binary tree of the mean and the target binary tree of the quantile exceeds the preset height difference range, then a first detection result indicating that the voltage of the direct current meets the preset stability condition is obtained.

[0101] Optionally, the above-mentioned deviation determination module 203 is specifically used to: calculate the difference of the second mean values ​​between each direct current in each time window and the difference of the second quantiles between each direct current in each time window according to the second mean values ​​and the second quantiles of each direct current in each time window, so as to obtain multiple second mean difference values ​​and multiple second quantile differences corresponding to each time window; use the direct current pair corresponding to the maximum value among the multiple second mean difference values ​​and the multiple second quantile differences as the target direct current; or use the direct current pair greater than a preset threshold among the multiple second mean difference values ​​and the multiple second quantile differences as the target direct current; or use the direct current pair corresponding to a preset number of values ​​in the difference sequence as the target direct current; wherein the difference sequence includes the multiple second mean difference values ​​and the multiple second quantile differences arranged in descending order of value.

[0102] Optionally, the above-mentioned second detection module 204 includes: a third calculation unit, used to calculate the voltage change rate of the target direct current within multiple preset time lengths according to the first voltage value of each pair of target direct currents; a fourth calculation unit, used to calculate the mutual information between the voltage change rates of each pair of target direct currents based on the voltage change rates; and a first determination unit, used to determine whether there is a synchronous change relationship between the voltages between each pair of target direct currents according to the mutual information, to obtain a second detection result.

[0103] Optionally, the fourth calculation unit is specifically used to: divide the voltage change rate into multiple average voltage change rate intervals according to the maximum and minimum values ​​of the voltage change rate; calculate the first probability that the voltage change rate of the target DC power belongs to each voltage change rate interval, and the second probability that the voltage change rate of the target DC power within the same preset time length belongs to the same voltage change rate interval according to the voltage change rate of the target DC power within multiple preset time lengths; calculate the mutual information between each pair of voltage change rates of the target DC power according to the first probability and the second probability.

[0104] Optionally, the abnormality determination module 205 is specifically configured to: determine that a virtual connection abnormality exists in the inverter if the second detection result indicates that the mutual information between the voltage change rates of any pair of target direct currents is greater than a preset mutual information threshold.

[0105] Optionally, the above-mentioned device also includes: a current acquisition module, used to obtain the first current value of multiple DC input paths of the inverter within a second specified time period; an access determination module, used to determine that the DC power input by the corresponding DC input path is a DC power path connected to the inverter if the first current value of any DC input path meets the preset access condition.

[0106] This embodiment also provides an electronic device, including a processor and a memory, wherein the memory stores machine executable instructions that can be executed by the processor, and the processor executes the machine executable instructions to implement the above-mentioned virtual connection abnormality detection method. The electronic device can be a server or a terminal device.

[0107] See also Figure 3 As shown, the electronic device includes a processor 100 and a memory 101. The memory 101 stores machine executable instructions that can be executed by the processor 100. The processor 100 executes the machine executable instructions to implement the above-mentioned virtual connection abnormality detection method.

[0108] Further, Figure 3 The electronic device shown further includes a bus 102 and a communication interface 103 , and the processor 100 , the communication interface 103 and the memory 101 are connected via the bus 102 .

[0109] The memory 101 may include a high-speed random access memory (RAM), and may also include a non-volatile memory, such as at least one disk storage. The communication connection between the system network element and at least one other network element is realized through at least one communication interface 103 (which may be wired or wireless), and the Internet, wide area network, local area network, metropolitan area network, etc. may be used. The bus 102 may be an ISA bus, a PCI bus, or an EISA bus, etc. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 3 Only one bidirectional arrow is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0110] The processor 100 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by the hardware integrated logic circuit or software instructions in the processor 100. The above processor 100 can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps and logic block diagrams disclosed in the embodiments of the present disclosure can be implemented or executed. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc. The steps of the method disclosed in conjunction with the embodiments of the present disclosure can be directly embodied as a hardware decoding processor for execution, or a combination of hardware and software modules in the decoding processor for execution. The software module may be located in a storage medium mature in the art, such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory 101, and the processor 100 reads the information in the memory 101 and completes the steps of the method of the above embodiment in combination with its hardware, for example:

[0111] Obtain a first voltage value of at least two direct currents connected to the inverter; wherein the first voltage value includes the voltage value of the direct current collected within a first specified time period; perform a voltage stability test on the first voltage value to obtain a first test result; wherein the first test result is used to indicate whether the voltage of the direct current meets a preset stability condition; if the first test result indicates that it does not meet the condition, determine at least one pair of target direct currents whose relative voltage deviation meets a preset deviation condition from at least two direct currents; perform a voltage synchronization change relationship test on each pair of target direct currents to obtain a second test result; and determine whether there is a virtual connection abnormality in the inverter based on the second test result.

[0112] In this method, by analyzing the voltage stability and voltage synchronous change relationship of each DC power of the inverter, the characteristics of the inverter virtual connection anomaly can be accurately extracted, thereby improving the accuracy of virtual connection anomaly detection.

[0113] Optionally, the first voltage value includes multiple values; the step of performing voltage stability detection on the first voltage value to obtain a first detection result includes: calculating the mean and quantile of the first voltage value of each direct current to obtain the first mean and first quantile corresponding to each direct current; calculating the mean and quantile of the first voltage values ​​corresponding to multiple time windows within a first specified time period to obtain the second mean and second quantile of each direct current in each time window; based on the first mean, the second mean, the first quantile and the second quantile, respectively constructing a target binary tree of the mean and quantile; according to the target binary tree, determining whether the voltage of the direct current meets the preset stability condition to obtain the first detection result.

[0114] Optionally, the steps of constructing target binary trees of means and quantiles based on the first mean, the second mean, the first quantile and the second quantile, respectively, include: calculating the difference in the first mean between the direct currents and the difference in the first quantile between the direct currents according to the first mean and the first quantile corresponding to each direct current, to obtain multiple first mean difference values ​​and multiple first quantile differences; calculating the difference in the second mean between the direct currents and the difference in the second quantile between the direct currents in each time window according to the second mean and the second quantile of each direct current in each time window, to obtain multiple second mean difference values ​​and multiple second quantile differences corresponding to each time window; constructing target binary trees of means and quantiles according to the multiple first mean difference values, the multiple first quantile differences, and the multiple second mean difference values ​​and the multiple second quantile differences corresponding to each time window.

[0115] Optionally, the steps of constructing target binary trees for means and quantiles respectively according to multiple first mean difference values, multiple first quantile difference values, and multiple second mean difference values ​​and multiple second quantile difference values ​​corresponding to each time window include: taking the maximum difference value as the root node of the binary tree, comparing the difference residual value with the root node, and taking the difference residual value as the child node of the root node to obtain a basic binary tree; wherein the maximum difference value is the maximum value of the maximum first mean difference value and the maximum first quantile difference, and the difference residual value is the value of the maximum first mean difference value and the maximum first quantile difference except the maximum difference value; recursively inserting the maximum second mean difference value corresponding to each time window into the basic binary tree to obtain a target binary tree for the mean; recursively inserting the maximum second quantile difference corresponding to each time window into the basic binary tree to obtain a target binary tree for the quantile.

[0116] Optionally, the step of determining whether the voltage of the direct current meets the preset stability condition based on the target binary tree and obtaining a first detection result includes: judging whether the height of the target binary tree is greater than a preset height threshold, and whether the height difference between the target binary tree of the mean and the target binary tree of the quantile is within a preset height difference range; if the heights of the target binary trees are all less than the preset height threshold, and the height difference between the target binary tree of the mean and the target binary tree of the quantile is within the preset height difference range, then a first detection result indicating that the voltage of the direct current does not meet the preset stability condition is obtained; if the height of any target binary tree is greater than or equal to the preset height threshold, and / or the height difference between the target binary tree of the mean and the target binary tree of the quantile exceeds the preset height difference range, then a first detection result indicating that the voltage of the direct current meets the preset stability condition is obtained.

[0117] Optionally, the step of determining at least one pair of target direct currents whose relative voltage deviations meet preset deviation conditions from at least two direct currents includes: calculating the difference in the second means and the difference in the second quantiles between the direct currents in each time window according to the second means and the second quantiles of the direct currents in each time window, to obtain multiple second mean differences and multiple second quantile differences corresponding to each time window; taking a direct current pair corresponding to the maximum value among the multiple second mean differences and the multiple second quantile differences as the target direct current; or taking a direct current pair whose value among the multiple second mean differences and the multiple second quantile differences is greater than a preset threshold as the target direct current; or taking a direct current pair corresponding to a preset number of values ​​in a difference sequence as the target direct current; wherein the difference sequence includes multiple second mean differences and multiple second quantile differences arranged in descending order.

[0118] Optionally, the step of performing voltage synchronous change relationship detection on each pair of target direct currents to obtain a second detection result includes: calculating the voltage change rate of the target direct current within a plurality of preset time lengths based on the first voltage value of each pair of target direct currents; calculating the mutual information between the voltage change rates of each pair of target direct currents based on the voltage change rate; and determining whether there is a synchronous change relationship between the voltages of each pair of target direct currents based on the mutual information to obtain a second detection result.

[0119] Optionally, based on the voltage change rate, the step of calculating the mutual information between the voltage change rates of each pair of target direct currents includes: dividing the voltage change rate into multiple average voltage change rate intervals according to the maximum and minimum values ​​in the voltage change rate; calculating, based on the voltage change rates of the target direct currents within multiple preset time lengths, a first probability that the voltage change rates of the target direct currents belong to each voltage change rate interval, and a second probability that the voltage change rates of the target direct currents within the same preset time length belong to the same voltage change rate interval; and calculating the mutual information between the voltage change rates of each pair of target direct currents based on the first probability and the second probability.

[0120] Optionally, the step of determining whether the inverter has a virtual connection abnormality based on the second detection result includes: if the second detection result indicates that the mutual information between the voltage change rates of any pair of target direct currents is greater than a preset mutual information threshold, determining that the inverter has a virtual connection abnormality.

[0121] Optionally, before the step of obtaining the first voltage values ​​of at least two DC power paths connected to the inverter, the method also includes: obtaining the first current values ​​of multiple DC input paths of the inverter within a second specified time period; if the first current value of any DC input path meets the preset access condition, it is determined that the DC power input by the corresponding DC input path is a DC power path connected to the inverter.

[0122] This embodiment further provides a computer-readable storage medium, which stores computer-executable instructions. When the computer-executable instructions are called and executed by a processor, the computer-executable instructions prompt the processor to implement the above-mentioned virtual connection abnormality detection method, for example:

[0123] Obtain a first voltage value of at least two direct currents connected to the inverter; wherein the first voltage value includes the voltage value of the direct current collected within a first specified time period; perform a voltage stability test on the first voltage value to obtain a first test result; wherein the first test result is used to indicate whether the voltage of the direct current meets a preset stability condition; if the first test result indicates that it does not meet the condition, determine at least one pair of target direct currents whose relative voltage deviation meets a preset deviation condition from at least two direct currents; perform a voltage synchronization change relationship test on each pair of target direct currents to obtain a second test result; and determine whether there is a virtual connection abnormality in the inverter based on the second test result.

[0124] In this method, by analyzing the voltage stability and voltage synchronous change relationship of each DC power of the inverter, the characteristics of the inverter virtual connection anomaly can be accurately extracted, thereby improving the accuracy of virtual connection anomaly detection.

[0125] Optionally, the first voltage value includes multiple values; the step of performing voltage stability detection on the first voltage value to obtain a first detection result includes: calculating the mean and quantile of the first voltage value of each direct current to obtain the first mean and first quantile corresponding to each direct current; calculating the mean and quantile of the first voltage values ​​corresponding to multiple time windows within a first specified time period to obtain the second mean and second quantile of each direct current in each time window; based on the first mean, the second mean, the first quantile and the second quantile, respectively constructing a target binary tree of the mean and quantile; according to the target binary tree, determining whether the voltage of the direct current meets the preset stability condition to obtain the first detection result.

[0126] Optionally, the steps of constructing target binary trees of means and quantiles based on the first mean, the second mean, the first quantile and the second quantile, respectively, include: calculating the difference in the first mean between the direct currents and the difference in the first quantile between the direct currents according to the first mean and the first quantile corresponding to each direct current, to obtain multiple first mean difference values ​​and multiple first quantile differences; calculating the difference in the second mean between the direct currents and the difference in the second quantile between the direct currents in each time window according to the second mean and the second quantile of each direct current in each time window, to obtain multiple second mean difference values ​​and multiple second quantile differences corresponding to each time window; constructing target binary trees of means and quantiles according to the multiple first mean difference values, the multiple first quantile differences, and the multiple second mean difference values ​​and the multiple second quantile differences corresponding to each time window.

[0127] Optionally, the steps of constructing target binary trees for means and quantiles respectively according to multiple first mean difference values, multiple first quantile difference values, and multiple second mean difference values ​​and multiple second quantile difference values ​​corresponding to each time window include: taking the maximum difference value as the root node of the binary tree, comparing the difference residual value with the root node, and taking the difference residual value as the child node of the root node to obtain a basic binary tree; wherein the maximum difference value is the maximum value of the maximum first mean difference value and the maximum first quantile difference, and the difference residual value is the value of the maximum first mean difference value and the maximum first quantile difference except the maximum difference value; recursively inserting the maximum second mean difference value corresponding to each time window into the basic binary tree to obtain a target binary tree for the mean; recursively inserting the maximum second quantile difference corresponding to each time window into the basic binary tree to obtain a target binary tree for the quantile.

[0128] Optionally, the step of determining whether the voltage of the direct current meets the preset stability condition based on the target binary tree and obtaining a first detection result includes: judging whether the height of the target binary tree is greater than a preset height threshold, and whether the height difference between the target binary tree of the mean and the target binary tree of the quantile is within a preset height difference range; if the heights of the target binary trees are all less than the preset height threshold, and the height difference between the target binary tree of the mean and the target binary tree of the quantile is within the preset height difference range, then a first detection result indicating that the voltage of the direct current does not meet the preset stability condition is obtained; if the height of any target binary tree is greater than or equal to the preset height threshold, and / or the height difference between the target binary tree of the mean and the target binary tree of the quantile exceeds the preset height difference range, then a first detection result indicating that the voltage of the direct current meets the preset stability condition is obtained.

[0129] Optionally, the step of determining at least one pair of target direct currents whose relative voltage deviations meet preset deviation conditions from at least two direct currents includes: calculating the difference in the second means and the difference in the second quantiles between the direct currents in each time window according to the second means and the second quantiles of the direct currents in each time window, to obtain multiple second mean differences and multiple second quantile differences corresponding to each time window; taking a direct current pair corresponding to the maximum value among the multiple second mean differences and the multiple second quantile differences as the target direct current; or taking a direct current pair whose value among the multiple second mean differences and the multiple second quantile differences is greater than a preset threshold as the target direct current; or taking a direct current pair corresponding to a preset number of values ​​in a difference sequence as the target direct current; wherein the difference sequence includes multiple second mean differences and multiple second quantile differences arranged in descending order.

[0130] Optionally, the step of performing voltage synchronous change relationship detection on each pair of target direct currents to obtain a second detection result includes: calculating the voltage change rate of the target direct current within a plurality of preset time lengths based on the first voltage value of each pair of target direct currents; calculating the mutual information between the voltage change rates of each pair of target direct currents based on the voltage change rate; and determining whether there is a synchronous change relationship between the voltages of each pair of target direct currents based on the mutual information to obtain a second detection result.

[0131] Optionally, based on the voltage change rate, the step of calculating the mutual information between the voltage change rates of each pair of target direct currents includes: dividing the voltage change rate into multiple average voltage change rate intervals according to the maximum and minimum values ​​in the voltage change rate; calculating, based on the voltage change rates of the target direct currents within multiple preset time lengths, a first probability that the voltage change rates of the target direct currents belong to each voltage change rate interval, and a second probability that the voltage change rates of the target direct currents within the same preset time length belong to the same voltage change rate interval; and calculating the mutual information between the voltage change rates of each pair of target direct currents based on the first probability and the second probability.

[0132] Optionally, the step of determining whether the inverter has a virtual connection abnormality based on the second detection result includes: if the second detection result indicates that the mutual information between the voltage change rates of any pair of target direct currents is greater than a preset mutual information threshold, determining that the inverter has a virtual connection abnormality.

[0133] Optionally, before the step of obtaining the first voltage values ​​of at least two DC power paths connected to the inverter, the method also includes: obtaining the first current values ​​of multiple DC input paths of the inverter within a second specified time period; if the first current value of any DC input path meets the preset access condition, it is determined that the DC power input by the corresponding DC input path is a DC power path connected to the inverter.

[0134] The computer program product of the method, device, electronic device and storage medium for detecting virtual connection anomalies provided in the embodiments of the present disclosure includes a computer-readable storage medium storing program code. The instructions included in the program code can be used to execute the methods described in the previous method embodiments. The specific implementation can be found in the method embodiments, which will not be repeated here.

[0135] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the system and device described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0136] In addition, in the description of the embodiments of the present disclosure, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present disclosure can be understood according to specific circumstances.

[0137] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present disclosure, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present disclosure. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0138] In the description of the present disclosure, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present disclosure and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present disclosure. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0139] Finally, it should be noted that the above embodiments are only specific implementation methods of the present disclosure, which are used to illustrate the technical solutions of the present disclosure, rather than to limit them. The protection scope of the present disclosure is not limited thereto. Although the present disclosure is described in detail with reference to the above embodiments, those skilled in the art should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above embodiments within the technical scope disclosed in the present disclosure, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present disclosure, and should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A method for detecting virtual connection anomalies, characterized in that: The method comprises: Acquire a first voltage value of at least two direct currents connected to the inverter; wherein the first voltage value includes a voltage value of the direct current collected within a first specified time period; Performing a voltage stability test on the first voltage value to obtain a first test result; wherein the first test result is used to indicate whether the voltage of the direct current meets a preset stability condition; If the first detection result indicates non-compliance, determining at least one pair of target direct currents whose relative voltage deviations meet a preset deviation condition from the at least two direct currents; Perform voltage synchronous change relationship detection on each pair of target direct currents to obtain a second detection result; According to the second detection result, it is determined whether the inverter has a virtual connection abnormality.

2. The method according to claim 1, characterized in that: The first voltage value includes a plurality of values; the step of performing voltage stability detection on the first voltage value to obtain a first detection result includes: Calculate the mean and quantile of the first voltage value of each direct current to obtain the first mean and first quantile corresponding to each direct current; Calculating the mean and quantile of the first voltage values ​​corresponding to the multiple time windows within the first specified time period to obtain the second mean and second quantile of each DC power in each time window; Based on the first mean, the second mean, the first quantile, and the second quantile, construct target binary trees of the mean and quantile respectively; According to the target binary tree, it is determined whether the voltage of the direct current meets a preset stability condition, and a first detection result is obtained.

3. The method according to claim 2, characterized in that The step of constructing target binary trees of means and quantiles based on the first mean, the second mean, the first quantile and the second quantile, respectively, comprises: Calculate the difference of the first mean values ​​between the direct currents and the difference of the first quantiles between the direct currents according to the first mean values ​​and the first quantiles corresponding to the direct currents to obtain a plurality of first mean difference values ​​and a plurality of first quantile difference values; According to the second mean and the second quantile of each direct current in each time window, the difference of the second mean values ​​between each direct current in each time window and the difference of the second quantiles between each direct current are calculated to obtain multiple second mean difference values ​​and multiple second quantile differences corresponding to each time window; According to the multiple first mean difference values, the multiple first quantile difference values, and the multiple second mean difference values ​​and the multiple second quantile difference values ​​corresponding to each time window, target binary trees of means and quantiles are constructed respectively.

4. The method according to claim 3, characterized in that The step of constructing target binary trees of means and quantiles respectively according to the multiple first mean difference values, the multiple first quantile difference values, and the multiple second mean difference values ​​and the multiple second quantile difference values ​​corresponding to each time window comprises: The maximum difference value is taken as the root node of the binary tree, and the difference residual value is compared with the root node, and the difference residual value is taken as the child node of the root node to obtain a basic binary tree; wherein the maximum difference value is the maximum value of the maximum first average difference value and the maximum first quantile difference value, and the difference residual value is the value of the maximum first average difference value and the maximum first quantile difference value other than the maximum difference value; Recursively insert the maximum second mean difference value corresponding to each time window into the basic binary tree to obtain a target binary tree of the mean value; The maximum second quantile difference corresponding to each time window is recursively inserted into the basic binary tree to obtain a target binary tree of quantiles.

5. The method according to claim 2, characterized in that: The step of determining whether the voltage of the DC power meets a preset stability condition according to the target binary tree to obtain a first detection result includes: Determine whether the height of the target binary tree is greater than a preset height threshold, and whether the height difference between the target binary tree of the mean and the target binary tree of the quantile is within a preset height difference range; If the heights of the target binary trees are all less than a preset height threshold, and the height difference between the target binary tree of the mean and the target binary tree of the quantile is within a preset height difference range, a first detection result indicating that the voltage of the direct current does not meet a preset stability condition is obtained; If the height of any target binary tree is greater than or equal to a preset height threshold, and / or the height difference between the target binary tree of the mean and the target binary tree of the quantile exceeds a preset height difference range, a first detection result indicating that the voltage of the direct current meets a preset stability condition is obtained.

6. The method according to claim 2, characterized in that The step of determining at least one pair of target direct currents whose relative voltage deviations meet a preset deviation condition from the at least two direct currents comprises: According to the second mean and the second quantile of each direct current in each time window, the difference of the second mean values ​​between each direct current in each time window and the difference of the second quantiles between each direct current are calculated to obtain multiple second mean difference values ​​and multiple second quantile differences corresponding to each time window; The DC current pair corresponding to the maximum value among the multiple second mean differences and the multiple second quantile differences is taken as the target DC current; or, the DC current pair greater than a preset threshold among the multiple second mean differences and the multiple second quantile differences is taken as the target DC current; or, the DC current pair corresponding to a preset number of values ​​in the difference sequence is taken as the target DC current; wherein the difference sequence includes the multiple second mean differences and the multiple second quantile differences arranged in descending order of value.

7. The method according to claim 1, characterized in that The step of detecting the voltage synchronous change relationship of each pair of target direct currents to obtain a second detection result includes: Calculating the voltage change rate of the target direct current within a plurality of preset time lengths according to each pair of first voltage values ​​of the target direct current; Based on the voltage change rate, calculating the mutual information between each pair of voltage change rates of the target direct current; It is determined based on the mutual information whether there is a synchronous change relationship between the voltages of each pair of target direct currents, and a second detection result is obtained.

8. The method according to claim 7, characterized in that The step of calculating the mutual information between each pair of voltage change rates of target direct current based on the voltage change rate comprises: Dividing the voltage change rate into a plurality of average voltage change rate intervals according to the maximum value and the minimum value of the voltage change rate; Calculate, according to the voltage change rates of the target DC power within a plurality of preset time lengths, a first probability that the voltage change rate of the target DC power belongs to each voltage change rate interval, and a second probability that the voltage change rate of the target DC power within the same preset time length belongs to the same voltage change rate interval; The mutual information between each pair of target direct current voltage change rates is calculated according to the first probability and the second probability.

9. The method according to claim 7, characterized in that: The step of determining whether the inverter has a virtual connection abnormality according to the second detection result includes: If the second detection result indicates that the mutual information between the voltage change rates of any pair of target direct currents is greater than a preset mutual information threshold, it is determined that a virtual connection abnormality exists in the inverter.

10. The method according to claim 1, characterized in that Before the step of obtaining the first voltage values ​​of at least two direct currents connected to the inverter, the method further includes: Obtaining first current values ​​of multiple DC input paths of the inverter within a second specified time period; If the first current value of any DC input path meets the preset access condition, it is determined that the DC power input by the corresponding DC input path is a DC power path connected to the inverter.

11. A device for detecting abnormal virtual connection, characterized in that: The device comprises: A data acquisition module, used to acquire a first voltage value of at least two direct currents connected to the inverter; wherein the first voltage value includes a voltage value of the direct current collected within a first specified time period; a first detection module, configured to perform a voltage stability detection on the first voltage value to obtain a first detection result; wherein the first detection result is used to indicate whether the voltage of the direct current meets a preset stability condition; a deviation determination module, configured to determine, from the at least two DC currents, at least one pair of target DC currents whose relative voltage deviations meet a preset deviation condition if the first detection result indicates non-compliance; A second detection module is used to detect the voltage synchronous change relationship of each pair of target direct currents to obtain a second detection result; An abnormality determination module is used to determine whether there is a virtual connection abnormality in the inverter according to the second detection result.

12. An electronic device, characterized in that: The invention comprises a processor and a memory, wherein the memory stores machine executable instructions that can be executed by the processor, and the processor executes the machine executable instructions to implement the method for detecting virtual connection anomalies according to any one of claims 1 to 10.

13. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions. When the computer-executable instructions are called and executed by a processor, the computer-executable instructions prompt the processor to implement the method for detecting virtual connection anomalies according to any one of claims 1 to 10.

Images