CN117310408A - Method and device for determining fault arc, photovoltaic system and medium - Google Patents
Method and device for determining fault arc, photovoltaic system and medium Download PDFInfo
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H1/00—Details of emergency protective circuit arrangements
- H02H1/0007—Details of emergency protective circuit arrangements concerning the detecting means
- H02H1/0015—Using arc detectors
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/12—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing
- G01R31/1227—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/12—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing
- G01R31/14—Circuits therefor, e.g. for generating test voltages, sensing circuits
Abstract
The invention discloses a method and a device for determining fault arc, a photovoltaic system and a medium, and relates to the technical field of photovoltaics. The method comprises the following steps: acquiring a high-frequency arc signal; at the moment, a high-frequency arc signal is directly obtained, so that the situation that the low-frequency characteristic is easily interfered by the environment and misjudgment and missed judgment of a fault arc are avoided due to the fact that the corresponding low-frequency characteristic is obtained according to the low-frequency arc signal; determining a reference value under a target frequency point of the target frequency channel according to the high-frequency arc signal; determining a reference frequency point sum and a frequency point sum under a target frequency point according to a reference value under the target frequency point of the target frequency channel; determining a dimensionless characteristic value according to the reference frequency point and the target frequency point; and determining the fault arc according to the dimensionless characteristic value. Meanwhile, the accuracy of determining the fault arc is further improved due to the fact that the reference value and the dimensionless characteristic value are determined according to the high-frequency arc signal, and unnecessary manpower maintenance cost and potential safety hazards increased by the fact that the fault arc is wrongly judged are avoided.
Description
Technical Field
The present invention relates to the field of photovoltaic technologies, and in particular, to a method and apparatus for determining a fault arc, a photovoltaic system, and a medium.
Background
With the high-speed development of the photovoltaic power generation technology, disasters such as fire disaster and the like caused by direct current fault arcs in the photovoltaic system seriously threaten the safe operation of the photovoltaic system. The existing fault arc detection generally obtains a low-frequency arc signal through sampling, and obtains a corresponding low-frequency characteristic according to the low-frequency arc signal, however, the low-frequency characteristic is easy to be interfered by the environment, under the scene of field application of an actual photovoltaic system, the fault arc can be misjudged and missed, and the unnecessary manpower maintenance cost and potential safety hazard can be increased due to the wrong fault arc judgment result.
In view of the above-mentioned problems, it is a matter of great effort for the person skilled in the art to find how to accurately determine a fault arc.
Disclosure of Invention
The invention aims to provide a method, a device, a photovoltaic system and a medium for determining a fault arc, which are used for solving the problems that corresponding low-frequency characteristics obtained through sampled low-frequency arc signals are easy to be interfered by environment and misjudgment and missed judgment of the fault arc occur.
In order to solve the technical problems, the invention provides a method for determining a fault arc, which is applied to a photovoltaic system in which a photovoltaic panel is connected with an inverter, and comprises the following steps:
acquiring a high-frequency arc signal;
determining a reference value under a target frequency point of the target frequency channel according to the high-frequency arc signal;
determining a reference frequency point sum and a frequency point sum under a target frequency point according to a reference value under the target frequency point of the target frequency channel;
determining a dimensionless characteristic value according to the sum of the reference frequency points and the sum of the frequency points;
and determining the fault arc according to the dimensionless characteristic value.
On the other hand, after acquiring the high-frequency arc signal, before determining the reference value at the target frequency point of the target frequency channel from the high-frequency arc signal, further comprising:
and sequentially carrying out singular value decomposition treatment, fourier transformation treatment and mean value filtering treatment on the high-frequency arc signal to obtain a frequency domain characteristic value.
On the other hand, determining the reference value at the target frequency point of the target frequency channel from the high-frequency arc signal includes:
setting a half-wave period;
acquiring frequency domain characteristic values corresponding to all frequency points in a half-wave period;
and carrying out average value processing on the frequency domain characteristic values to obtain a reference value under the target frequency point.
On the other hand, determining the dimensionless feature value according to the reference frequency point sum and the frequency point sum comprises:
and dividing the frequency point sum serving as a divisor, and the reference frequency point sum serving as a divisor to obtain a dimensionless characteristic value.
In another aspect, determining a fault arc from the dimensionless feature values includes:
judging whether a dimensionless characteristic value larger than 1 reaches a triggering condition or not;
if the dimensionless characteristic value larger than 1 does not reach the triggering condition, ending;
if the dimensionless characteristic value larger than 1 reaches the triggering condition, summing the dimensionless characteristic values to obtain a dimensionless characteristic sum;
judging whether the dimensionless characteristics and the preset limiting conditions are met or not;
if the dimensionless characteristics are not found and the preset limiting conditions are met, determining that the high-frequency arc signal is a fault arc;
and if the dimensionless characteristics and the preset limiting conditions are not met, determining that no fault arc exists.
On the other hand, after determining the high-frequency arc signal as the fault arc, further comprising:
and controlling a release arranged in the photovoltaic system to be disconnected.
On the other hand, after determining the reference value at the target frequency point of the target frequency channel from the high-frequency arc signal, before determining the dimensionless feature value from the reference frequency point and the sum frequency point, the method further comprises:
the reference value is updated and calibrated in real time.
In order to solve the technical problem, the invention also provides a device for determining fault arc, which is applied to a photovoltaic system in which a photovoltaic panel is connected with an inverter, and the device comprises:
the first acquisition module is used for acquiring a high-frequency arc signal;
the first determining module is used for determining a reference value under a target frequency point of the target frequency channel according to the high-frequency arc signal;
the second determining module is used for determining a reference frequency point sum and a frequency point sum under the target frequency point according to the reference value under the target frequency point of the target frequency channel;
the third determining module is used for determining a dimensionless characteristic value according to the sum of the reference frequency points and the sum of the frequency points;
and the fourth determining module is used for determining the fault arc according to the dimensionless characteristic value.
Furthermore, the device comprises the following modules:
on the other hand, after acquiring the high-frequency arc signal, before determining the reference value at the target frequency point of the target frequency channel from the high-frequency arc signal, further comprising:
the first obtaining module is used for sequentially carrying out singular value decomposition processing, fourier transformation processing and mean value filtering processing on the high-frequency arc signals to obtain frequency domain characteristic values.
On the other hand, determining the reference value at the target frequency point of the target frequency channel from the high-frequency arc signal includes:
the setting module is used for setting a half-wave period;
the second acquisition module is used for acquiring frequency domain characteristic values corresponding to all frequency points in the half-wave period;
and the second obtaining module is used for carrying out mean value processing on the frequency domain characteristic values to obtain a reference value under the target frequency point.
On the other hand, determining the dimensionless feature value according to the reference frequency point sum and the frequency point sum comprises:
and the third obtaining module is used for dividing the frequency point sum serving as a divisor, and the reference frequency point sum serving as a divisor to obtain a dimensionless characteristic value.
In another aspect, determining a fault arc from the dimensionless feature values includes:
the first judging module is used for judging whether the dimensionless characteristic value larger than 1 reaches a triggering condition or not;
if the dimensionless characteristic value larger than 1 does not reach the triggering condition, ending;
if the dimensionless characteristic value larger than 1 reaches the triggering condition, triggering a summation module, wherein the summation module is used for summing the dimensionless characteristic values to obtain dimensionless characteristic sums;
the second judging module is used for judging whether the dimensionless characteristics and the preset limiting conditions are met or not;
if the dimensionless characteristics are not found and the preset limiting conditions are met, triggering a fifth determining module for determining that the high-frequency arc signal is a fault arc;
and if the dimensionless characteristic and the preset limiting condition are not met, triggering a sixth determining module for determining the fault-free arc.
On the other hand, after determining the high-frequency arc signal as the fault arc, further comprising:
and the control module is used for controlling the release arranged in the photovoltaic system to be disconnected.
On the other hand, after determining the reference value at the target frequency point of the target frequency channel from the high-frequency arc signal, before determining the dimensionless feature value from the reference frequency point and the sum frequency point, the method further comprises:
and the real-time updating module is used for updating and calibrating the reference value in real time.
In order to solve the technical problem, the present invention further provides a photovoltaic system, including:
a memory for storing a computer program;
a processor for executing a computer program to perform the steps of the method of determining a fault arc.
To solve the above technical problem, the present invention further provides a computer readable storage medium, on which a computer program is stored, which when executed by a processor, implements the steps of the above method for determining a fault arc in total.
The invention provides a method for determining fault arc, which is applied to a photovoltaic system with a photovoltaic panel connected with an inverter, and comprises the following steps: acquiring a high-frequency arc signal; at the moment, a high-frequency arc signal is directly obtained, so that the situation that the low-frequency characteristic is easily interfered by the environment and misjudgment and missed judgment of a fault arc are avoided due to the fact that the corresponding low-frequency characteristic is obtained according to the low-frequency arc signal; determining a reference value under a target frequency point of the target frequency channel according to the high-frequency arc signal; determining a reference frequency point sum and a frequency point sum under a target frequency point according to a reference value under the target frequency point of the target frequency channel; determining a dimensionless characteristic value according to the sum of the reference frequency points and the sum of the frequency points; and determining the fault arc according to the dimensionless characteristic value. Meanwhile, the accuracy of determining the fault arc is further improved due to the fact that the reference value and the dimensionless characteristic value are determined according to the high-frequency arc signal, and unnecessary manpower maintenance cost and potential safety hazards increased by the fact that the fault arc is wrongly judged are avoided.
The invention also provides a device for determining the fault arc, a photovoltaic system and a medium, and the effects are the same as above.
Drawings
For a clearer description of embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described, it being apparent that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to the drawings without inventive effort for those skilled in the art.
FIG. 1 is a flow chart of a method for determining a fault arc according to an embodiment of the present invention;
fig. 2 is a circuit diagram of a sampling circuit according to an embodiment of the present invention;
FIG. 3 is a block diagram of an apparatus for determining a fault arc according to an embodiment of the present invention;
fig. 4 is a block diagram of a photovoltaic system according to an embodiment of the present invention.
Wherein 10 is a filter circuit.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without making any inventive effort are within the scope of the present invention.
The core of the invention is to provide a method, a device, a photovoltaic system and a medium for determining a fault arc, which can avoid the situation that the corresponding low-frequency characteristic is obtained according to a low-frequency arc signal, so that the low-frequency characteristic is easy to be interfered by the environment, and misjudgment and missed judgment of the fault arc occur; meanwhile, the accuracy of determining the fault arc is further improved due to the fact that the reference value and the dimensionless characteristic value are determined according to the high-frequency arc signal, and unnecessary manpower maintenance cost and potential safety hazards increased by the fact that the fault arc is wrongly judged are avoided.
In order to better understand the aspects of the present invention, the present invention will be described in further detail with reference to the accompanying drawings and detailed description.
Fig. 1 is a flowchart of a method for determining a fault arc according to an embodiment of the present invention, where, as shown in fig. 1, the method for determining a fault arc is applied to a photovoltaic system in which a photovoltaic panel is connected to an inverter, and includes:
s10: acquiring a high-frequency arc signal;
after acquiring the high-frequency arc signal, before determining the reference value at the target frequency point of the target frequency channel according to the high-frequency arc signal, the method further comprises: sequentially performing singular value decomposition processing, fourier transform processing and mean value filtering processing on the high-frequency arc signal to obtain a frequency domain characteristic value;
s11: determining a reference value under a target frequency point of the target frequency channel according to the high-frequency arc signal;
it will be appreciated that there will be a plurality of high frequency channels in a photovoltaic system, where the target frequency channel is a selected fixed high frequency channel, and the frequency points may be exemplified by: a frequency point of 2MHz, in this embodiment, a plurality of frequency points with different frequency values may be set, which is not limited in this embodiment;
s12: determining a reference frequency point sum and a frequency point sum under a target frequency point according to a reference value under the target frequency point of the target frequency channel;
s13: determining a dimensionless characteristic value according to the sum of the reference frequency points and the sum of the frequency points;
s14: and determining the fault arc according to the dimensionless characteristic value.
In addition, fig. 2 is a circuit diagram of a sampling circuit according to an embodiment of the present invention, as shown in fig. 2, in which a current transformer CT is connected to a photovoltaic system, and a transient voltage suppression diode (Transient Voltage Suppressor, TVS) is connected in parallel to the current transformer, and a transient voltage suppression diode VP1 is also connected in parallel to a filter circuit 10. The filter circuit 10 includes at least a first resistor, a second resistor, a third resistor, a first capacitor, and a second capacitor; the first end of the first resistor is connected with the first end of the first capacitor, the second end of the first capacitor is connected with the first end of the second resistor, a common end formed by the second end of the second resistor and the second end of the third resistor is used as an output end of the filter circuit, and a high-frequency arc signal for singular value decomposition, fourier transform and mean filtering is output at the output end of the filter circuit, the second end of the first resistor is connected with the first end of the second capacitor, and the second end of the second capacitor is connected with the first end of the third capacitor.
The high-frequency arc signal after the singular value decomposition process, the fourier transform process, and the mean filter process is an analog signal, and the analog signal is input to the digital-to-analog conversion unit, so that the high-frequency arc signal of the analog signal is converted into the high-frequency arc signal of the digital signal. As can be seen from this, the high-frequency arc signal input to the inverter is a digital signal. And the current transformer is adopted to sample high-frequency arc signals, so that the high-low voltage complete isolation is ensured, the safety is high, the remote measurement is convenient, and the effective detection extension line range is improved. The sampling circuit improves the safety protection performance of the circuit by connecting the transient voltage suppression diode VP1 with the resistor and the capacitor in the filter circuit in series and in parallel, filters the interference low-frequency signal and ensures the stability of the acquired high-frequency arc signal.
The inverter may be set to a maximum power point tracking solar controller (Maximum Power Point Tracking, MPPT) in this embodiment. The method for determining the fault arc can be performed in a detection unit, and it can be known that the detection unit can be arranged inside the inverter and also can be arranged as a detection unit connected with the inverter.
In the embodiment, because the high-frequency arc signal is directly obtained, the situation that the corresponding low-frequency characteristic is obtained according to the low-frequency arc signal, the low-frequency characteristic is easy to be interfered by the environment, and misjudgment and missed judgment of fault arc occur is avoided; meanwhile, the accuracy of determining the fault arc is further improved due to the fact that the reference value and the dimensionless characteristic value are determined according to the high-frequency arc signal, and unnecessary manpower maintenance cost and potential safety hazards increased by the fact that the fault arc is wrongly judged are avoided.
On the basis of the above-described embodiments, as a more preferable embodiment, determining the reference value at the target frequency point of the target frequency channel from the high-frequency arc signal includes:
setting a half-wave period;
acquiring frequency domain characteristic values corresponding to all frequency points in a half-wave period;
and carrying out average value processing on the frequency domain characteristic values to obtain a reference value under the target frequency point.
The half-wave period is a preset period interval duration, for example: when the half-wave period is set to be 5ms, the above-mentioned average processing is performed on the frequency domain characteristic values, that is, the average processing is performed again after summing the frequency domain characteristic values obtained in the half-wave period. At this time, based on all high-frequency arc signals in the half-wave period, frequency domain characteristic values T of all corresponding frequency points are generated i The formula for obtaining the frequency point sum is as follows:
wherein T is i Is the frequency domain eigenvalue, S i And M is 31 single-frequency point data corresponding to each target frequency channel i.
The formula for obtaining the reference frequency point sum is as follows:
wherein x is i-basis I is the reference frequency point sum, i is the target frequency channel, and N is the number of half-wave periods.
The formula for obtaining the reference value is as follows:
considering the working characteristics of the inverter, the arc signal is not unchanged, so that the function of a dynamic calibration reference is required to be shown, and the reference value of each target frequency channel is obtained for refreshing at intervals under the condition that the arc signal does not appear in the normal operation of the equipment, so that the dynamic adaptation of different environments is realized. Therefore, on the basis of the above-described embodiment, as a more preferable embodiment, after determining the reference value at the target frequency point of the target frequency channel from the high-frequency arc signal, before determining the dimensionless characteristic value from the reference frequency point and the sum frequency point, further includes: the reference value is updated and calibrated in real time.
Specifically, determining the dimensionless feature value according to the sum of the reference frequency points and the sum of the frequency points comprises: and dividing the frequency point sum serving as a divisor, and the reference frequency point sum serving as a divisor to obtain a dimensionless characteristic value.
Based on the reference value, the frequency point sum is used as a numerator, the reference frequency point sum is used as a denominator, the two are divided to obtain dimensionless characteristics, the dimensionless characteristics can well capture arc mutation characteristics, the arc mutation characteristics are not easy to be influenced by different environment background noise, board models and coil models, the universality is strong, and the calculation formula of the dimensionless characteristics is as follows:
wherein y is i Is non-dimensional, x i Is the frequency point sum of the target high-frequency channel.
In addition, determining a fault arc from the dimensionless feature values includes:
judging whether a dimensionless characteristic value larger than 1 reaches a triggering condition or not;
the triggering condition can be that the number of dimensionless characteristic values larger than 1 reaches a preset number;
if the dimensionless characteristic value larger than 1 does not reach the triggering condition, ending;
if the dimensionless characteristic value larger than 1 reaches the triggering condition, summing the dimensionless characteristic values to obtain a dimensionless characteristic sum;
judging whether the dimensionless characteristics and the preset limiting conditions are met or not;
if the dimensionless characteristics are not found and the preset limiting conditions are met, determining that the high-frequency arc signal is a fault arc;
and if the dimensionless characteristics and the preset limiting conditions are not met, determining that no fault arc exists.
It should be understood that, when the dimensionless number is determined, the dimensionless number may be set to be greater than 1.5, and the like, which is not limited in this embodiment.
In addition, the formula of the dimensionless feature sum is as follows:
wherein S is the sum of dimensionless characteristics, and L is the number of high-frequency channels for generating the dimensionless characteristics.
Marking the fault arc meeting the preset limiting condition as 1; an arc that does not meet the preset clipping condition is marked as 0.
And finally, inputting the result of the fault arc or the failure arc into a decision control module in real time, and carrying out further classification judgment on whether the arcing phenomenon occurs at the moment or not through a set half-wave strategy by combining the continuous characteristic of direct current arc combustion, wherein the output result is the fault arc or the failure arc.
On the basis of the above embodiment, as a more preferable embodiment, after determining that the high-frequency arc signal is a fault arc, it further includes: and controlling a release arranged in the photovoltaic system to be disconnected. At this time, the influence of the fault arc on the safety of the photovoltaic system can be avoided.
In the above embodiments, the method for determining the fault arc is described in detail, and the invention also provides a corresponding embodiment of the device for determining the fault arc. It should be noted that the present invention describes an embodiment of the device portion from two angles, one based on the angle of the functional module and the other based on the angle of the hardware.
Fig. 3 is a block diagram of a device for determining a fault arc according to an embodiment of the present invention, and as shown in fig. 3, the present invention further provides a device for determining a fault arc, which is applied to a photovoltaic system in which a photovoltaic panel is connected to an inverter, where the device includes:
a first acquisition module 20 for acquiring a high-frequency arc signal;
a first determining module 21, configured to determine a reference value at a target frequency point of the target frequency channel according to the high-frequency arc signal;
a second determining module 22, configured to determine a reference frequency point sum and a frequency point sum under the target frequency point according to the reference value under the target frequency point of the target frequency channel;
a third determining module 23, configured to determine a dimensionless feature value according to the sum of the reference frequency points and the sum of the frequency points;
a fourth determining module 24 is configured to determine a fault arc according to the dimensionless characteristic value.
Furthermore, the device comprises the following modules:
on the other hand, after acquiring the high-frequency arc signal, before determining the reference value at the target frequency point of the target frequency channel from the high-frequency arc signal, further comprising:
the first obtaining module is used for sequentially carrying out singular value decomposition processing, fourier transformation processing and mean value filtering processing on the high-frequency arc signals to obtain frequency domain characteristic values.
On the other hand, determining the reference value at the target frequency point of the target frequency channel from the high-frequency arc signal includes:
the setting module is used for setting a half-wave period;
the second acquisition module is used for acquiring frequency domain characteristic values corresponding to all frequency points in the half-wave period;
and the second obtaining module is used for carrying out mean value processing on the frequency domain characteristic values to obtain a reference value under the target frequency point.
On the other hand, determining the dimensionless feature value according to the reference frequency point sum and the frequency point sum comprises:
and the third obtaining module is used for dividing the frequency point sum serving as a divisor, and the reference frequency point sum serving as a divisor to obtain a dimensionless characteristic value.
In another aspect, determining a fault arc from the dimensionless feature values includes:
the first judging module is used for judging whether the dimensionless characteristic value larger than 1 reaches a triggering condition or not;
if the dimensionless characteristic value larger than 1 does not reach the triggering condition, ending;
if the dimensionless characteristic value larger than 1 reaches the triggering condition, triggering a summation module, wherein the summation module is used for summing the dimensionless characteristic values to obtain dimensionless characteristic sums;
the second judging module is used for judging whether the dimensionless characteristics and the preset limiting conditions are met or not;
if the dimensionless characteristics are not found and the preset limiting conditions are met, triggering a fifth determining module for determining that the high-frequency arc signal is a fault arc;
and if the dimensionless characteristic and the preset limiting condition are not met, triggering a sixth determining module for determining the fault-free arc.
On the other hand, after determining the high-frequency arc signal as the fault arc, further comprising:
and the control module is used for controlling the release arranged in the photovoltaic system to be disconnected.
On the other hand, after determining the reference value at the target frequency point of the target frequency channel from the high-frequency arc signal, before determining the dimensionless feature value from the reference frequency point and the sum frequency point, the method further comprises:
and the real-time updating module is used for updating and calibrating the reference value in real time.
Since the embodiments of the apparatus portion and the embodiments of the method portion correspond to each other, the embodiments of the apparatus portion are referred to the description of the embodiments of the method portion, and are not repeated herein.
Fig. 4 is a structural diagram of a photovoltaic system according to an embodiment of the present invention, as shown in fig. 4, a photovoltaic system includes:
a memory 40 for storing a computer program;
a processor 41 for carrying out the steps of the method of determining a fault arc as mentioned in the above embodiments when executing a computer program.
Processor 41 may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc., among others. The processor 41 may be implemented in at least one hardware form of digital signal processing (Digital Signal Processing, DSP), field programmable gate array (Field-Programmable Gate Array, FPGA), programmable logic array (Programmable Logic Array, PLA). The processor 41 may also comprise a main processor, which is a processor for processing data in an awake state, also called central processor (Central Processing Unit, CPU), and a coprocessor; a coprocessor is a low-power processor for processing data in a standby state. In some embodiments, the processor 41 may be integrated with an image processor (Graphics Processing Unit, GPU) for taking care of rendering and rendering of the content that the display screen is required to display. In some embodiments, the processor 41 may also include an artificial intelligence (Artificial Intelligence, AI) processor for processing computing operations related to machine learning.
Memory 40 may include one or more computer-readable storage media, which may be non-transitory. Memory 40 may also include high-speed random access memory, as well as non-volatile memory, such as one or more magnetic disk storage devices, flash memory storage devices. In this embodiment, the memory 40 is at least used to store a computer program that, when loaded and executed by the processor 41, enables the implementation of the relevant steps of the method for determining a fault arc disclosed in any of the foregoing embodiments. In addition, the resources stored in the memory 40 may also include an operating system, data, etc., and the storage manner may be transient storage or permanent storage. The operating system may include Windows, unix, linux, among others. The data may include, but is not limited to, a method of determining a fault arc, and the like.
In some embodiments, the photovoltaic system may further include a display screen, an input-output interface, a communication interface, a power supply, and a communication bus.
Those skilled in the art will appreciate that the structure shown in fig. 4 is not limiting of the photovoltaic system and may include more or fewer components than shown.
The photovoltaic system provided by the embodiment of the invention comprises the memory 40 and the processor 41, wherein the processor 41 can realize the method for determining the fault arc when executing the program stored in the memory 40.
Finally, the invention also provides a corresponding embodiment of the computer readable storage medium. The computer-readable storage medium has stored thereon a computer program which, when executed by a processor, performs the steps as described in the method embodiments above.
It will be appreciated that the methods of the above embodiments, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored on a computer readable storage medium. Based on this understanding, the technical solution of the present invention may be embodied essentially or in part or all of the technical solution or in part in the form of a software product stored in a storage medium for performing all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a usb disk, a removable hard disk, a Read-Only Memory (ROM), a random-access Memory (Random Access Memory, RAM), a magnetic disk, or an optical disk, or other various media capable of storing program codes.
The method, the device, the photovoltaic system and the medium for determining the fault arc provided by the invention are described in detail. In the description, each embodiment is described in a progressive manner, and each embodiment is mainly described by the differences from other embodiments, so that the same similar parts among the embodiments are mutually referred. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant points refer to the description of the method section. It should be noted that it will be apparent to those skilled in the art that various modifications and adaptations of the invention can be made without departing from the principles of the invention and these modifications and adaptations are intended to be within the scope of the invention as defined in the following claims.
It should also be noted that in this specification, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.
Claims (10)
1. A method of determining a fault arc for use in a photovoltaic system having a photovoltaic panel connected to an inverter, the method comprising:
acquiring a high-frequency arc signal;
determining a reference value under a target frequency point of a target frequency channel according to the high-frequency arc signal;
determining a reference frequency point sum and a target frequency point sum under the target frequency point according to the reference value under the target frequency point of the target frequency channel;
determining a dimensionless characteristic value according to the reference frequency point and the target frequency point;
and determining fault arc according to the dimensionless characteristic value.
2. The method of determining a fault arc according to claim 1, further comprising, after said acquiring the high frequency arc signal, before said determining a reference value at a target frequency point of a target frequency channel from said high frequency arc signal:
and sequentially carrying out singular value decomposition processing, fourier transformation processing and mean value filtering processing on the high-frequency arc signal to obtain a frequency domain characteristic value.
3. The method of determining a fault arc according to claim 2, wherein the determining a reference value at a target frequency point of a target frequency channel from the high frequency arc signal comprises:
setting a half-wave period;
acquiring the frequency domain characteristic values corresponding to all frequency points in the half-wave period;
and carrying out average processing on the frequency domain characteristic values to obtain the reference value under the target frequency point.
4. A method of determining a fault arc as claimed in claim 3, wherein said determining dimensionless characteristic values from the reference frequency point sum and the target frequency point sum comprises:
and dividing the frequency point sum serving as a divisor, and the reference frequency point sum serving as a divisor to obtain the dimensionless characteristic value.
5. The method of determining a fault arc of claim 1, wherein the determining a fault arc from the dimensionless characteristic values comprises:
judging whether the dimensionless characteristic value larger than 1 reaches a triggering condition or not;
if the dimensionless characteristic value larger than 1 does not reach the triggering condition, ending;
if the dimensionless characteristic value larger than 1 reaches the triggering condition, summing the dimensionless characteristic values to obtain a dimensionless characteristic sum;
judging whether the dimensionless characteristic sum meets a preset limiting condition or not;
if the dimensionless characteristics and the preset limiting conditions are met, determining that the high-frequency arc signal is a fault arc;
and if the dimensionless characteristic and the preset limiting condition are not met, determining that no fault arc exists.
6. The method of determining a fault arc of claim 5, further comprising, after said determining that the high frequency arc signal is a fault arc:
and controlling the release arranged in the photovoltaic system to be disconnected.
7. The method of determining a fault arc according to claim 1, further comprising, after said determining a reference value at a target frequency point of a target frequency channel from said high frequency arc signal, before said determining a dimensionless characteristic value from said reference frequency point and from said target frequency point:
the reference value is updated and calibrated in real time.
8. An apparatus for determining a fault arc for use in a photovoltaic system having a photovoltaic panel connected to an inverter, the apparatus comprising:
the first acquisition module is used for acquiring a high-frequency arc signal;
the first determining module is used for determining a reference value under a target frequency point of the target frequency channel according to the high-frequency arc signal;
the second determining module is used for determining a reference frequency point sum and a target frequency point sum under the target frequency point according to the reference value under the target frequency point of the target high-frequency channel;
the third determining module is used for determining a dimensionless characteristic value according to the reference frequency point and the target frequency point;
and the fourth determining module is used for determining the fault arc according to the dimensionless characteristic value.
9. A photovoltaic system, comprising:
a memory for storing a computer program;
a processor for carrying out the steps of the method of determining a fault arc as claimed in any one of claims 1 to 7 when said computer program is executed.
10. A computer-readable storage medium, characterized in that it has stored thereon a computer program which, when executed by a processor, implements the steps of the method of determining a fault arc as claimed in any one of claims 1 to 7.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN117650495A (en) * | 2024-01-30 | 2024-03-05 | 清华大学 | Flexible AC traction converter contact net fault transient voltage suppression method and device |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117650495A (en) * | 2024-01-30 | 2024-03-05 | 清华大学 | Flexible AC traction converter contact net fault transient voltage suppression method and device |
| CN117650495B (en) * | 2024-01-30 | 2024-04-09 | 清华大学 | Flexible AC traction converter contact net fault transient voltage suppression method and device |
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