Fireproof control method and device for direct-current combiner box, and computer medium
By high-frequency sampling and real-time analysis of the voltage, current and temperature of the DC bus box, the type and degree of arc are judged, and targeted control operations are carried out, the risk of fire caused by arc failure in the DC bus box is solved, and the fire risk is effectively reduced.
Patent Information
- Application Number
- CN202411797188.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-09
- Publication Date
- 2025-03-14
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
The prior art is difficult to effectively prevent fires caused by arc failure in DC crowd boxes, especially in unguarded areas.
By obtaining high-frequency sampling signals of voltage, current and temperature in each input channel of the DC bus box, the sampling signal characteristics are analyzed in real time, the type and degree of arc are judged, and the switch is controlled based on the judgment results to reduce fire risk.
Real-time monitoring and analysis of the arcs inside and outside the DC crowd box is realized, timely judged the probability of fire occurrence, and reduce fire risk through targeted control operations.
Smart Images
Figure CN119627787A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the photovoltaic field, and in particular to a DC combiner box fire prevention control method, device, and computer medium. Background Art
[0002] A combiner box means that users can connect a certain number of photovoltaic cells of the same specifications in series to form photovoltaic strings, and then connect several photovoltaic strings in parallel to the photovoltaic combiner box. After the photovoltaics are combined in the photovoltaic combiner box, they are used together through a controller, a DC distribution cabinet, a photovoltaic inverter, and an AC distribution cabinet to form a complete photovoltaic power generation system and achieve grid connection with the city power grid.
[0003] Since combiner boxes are generally installed in unattended areas, fire control of combiner boxes is very important. Summary of the invention
[0004] The purpose of the present application is to provide a DC combiner box fire prevention control method, device, and computer medium to obtain high-frequency sampling signals of voltage, current, and temperature of each input channel of the DC combiner box, perform real-time analysis on the sampling signal characteristics, obtain the type and degree of arcing, and judge the probability and location of fire according to the type and degree of arcing. The present application can timely detect the type and degree of arcing, comprehensively judge the probability of fire, make targeted control operations, and reduce the probability of fire risk.
[0005] To achieve the above objectives, this application provides the following solutions:
[0006] In a first aspect, the present application provides a DC combiner box fire prevention control method, comprising:
[0007] Obtain high-frequency sampling signals of voltage, current and temperature of each input channel of the DC combiner box;
[0008] Analyze the sampling signal characteristics in real time to obtain the type and degree of arc;
[0009] Determine the fire assessment value and location based on the type and degree of the arc, and control the switches inside and / or outside the DC combiner box based on the determination result to ensure the safety of the electrical network inside and / or outside the DC combiner box and avoid the occurrence of faults or fires;
[0010] The fire occurrence assessment value represents the probability of fire occurrence, and the larger the assessment value is, the greater the probability of fire occurrence is.
[0011] Preferably, the sampling frequency of the high-frequency sampling signals for acquiring the voltage, current and temperature of each input channel of the DC combiner box is not less than 1 kHz.
[0012] Preferably, the real-time analysis of the sampling signal characteristics to obtain the type and degree of the arc comprises:
[0013] The voltage, current and temperature at the same time are used as the first sample data;
[0014] Establishing a relationship model between the electric arc and the first sample data as a first model, training the first model, and determining whether an electric arc occurs in the electrical network by using the first model;
[0015] Calculate harmonic information through voltage and current information;
[0016] When an arc occurs, the voltage, current, harmonics and temperature at the same time are used as the second sample data;
[0017] For arcs of different types and degrees, relationship models between the arc and the second sample data are respectively established as the second model, and the second model is trained to determine the type and degree of the arc through the second model.
[0018] Preferably, the training method of the first model includes:
[0019] Simulating arcs of different degrees multiple times at various locations of the electrical network inside and outside the combiner box, and obtaining first sample data at the time when the arc occurs and multiple consecutive times before and after the arc occurs;
[0020] The plurality of first sample data are randomly divided into a training set and a test set according to a certain ratio, so as to ensure that the training set and the test set at least include the first sample data obtained from the arc simulation test at each position, each type and each degree;
[0021] The first sample data in the training set is used as the model input information, and the judgment result of whether an arc occurs is used as the model output information to train the model;
[0022] The accuracy of the trained model output result is verified through the validation set. When the accuracy is higher than the set value, the first model training is completed. Otherwise, the multiple first sample data are reclassified and trained until the first model training is completed.
[0023] Preferably, the training method of the second model includes:
[0024] Calculating a plurality of first sample data corresponding to the arc occurrence time in each simulation test to obtain corresponding harmonic information, thereby obtaining a plurality of second sample data;
[0025] The plurality of second sample data are randomly divided into a training set and a test set according to a certain ratio, so as to ensure that both the training set and the test set at least include the second sample data obtained from the arc simulation test at each position, each type and each degree;
[0026] The second sample data in the training set is used as the model input information, and the arc type and degree judgment result is used as the model output information to train the model;
[0027] The accuracy of the output results of the trained model is verified through the validation set. When the accuracy is higher than the set value, the second model training is completed. Otherwise, multiple second sample data are reclassified and trained until the second model training is completed.
[0028] Preferably, the arc types include aging arc inside the box, fault arc inside the box, aging arc outside the box, and fault arc outside the box; the arc degree is any parameter or combination of parameters including arc duration, arc occurrence frequency, current data fluctuation value when arc occurs, and temperature data fluctuation value when arc occurs.
[0029] Preferably, judging the fire occurrence assessment value and location according to the type and degree of the arc includes:
[0030] The fire occurrence assessment value is divided into a first assessment value and a second assessment value, the first assessment value corresponds to the fire occurrence assessment value inside the box, and the second assessment value corresponds to the fire occurrence assessment value outside the box; there are multiple first assessment values and second assessment values, which are divided according to the specific electrical line connection relationship, and different assessment values are calculated separately;
[0031] The arc degree is divided into N levels from low to high, where N is an integer greater than 0;
[0032] When the arc is an aging arc in the box, the arc degree corresponds to a level, and the first evaluation value is updated, where the updated first evaluation value = the first evaluation value before the update + N;
[0033] When the arc is a fault arc in the box, the arc degree corresponds to a level, and the first evaluation value is updated, and the updated first evaluation value = the first evaluation value before the update + k*N; wherein k is a fault weighting coefficient, which is set according to experience or actual use requirements;
[0034] When the arc is an aging arc outside the box, the arc degree corresponds to a level, and the second evaluation value is updated, where the updated second evaluation value = the second evaluation value before the update + N;
[0035] When the arc is an external fault arc, the arc degree is determined to correspond to a level, and the second evaluation value is updated. The updated second evaluation value = the second evaluation value before the update + k*N; wherein k is a fault weighting coefficient, which is set based on experience or actual usage requirements.
[0036] Preferably, the controlling of switches inside and / or outside the DC combiner box according to the judgment result includes:
[0037] When the first evaluation value ≥ M1, the arc type corresponding to the last update of the first evaluation value is determined. If it is an aging arc in the box, the switch does not operate and only an alarm is issued; if it is a fault arc in the box, the switch inside the combiner box is controlled to be disconnected and an alarm is issued;
[0038] When the second evaluation value ≥ M2, determine the arc type corresponding to the last update of the second evaluation value. If it is an aging arc outside the box, the switch will not operate and only an alarm will be issued. If it is a fault arc outside the box, the switch corresponding to the line corresponding to the second evaluation value outside the junction box will be controlled to disconnect and an alarm will be issued.
[0039] In a second aspect, the present application provides a DC combiner box fire prevention control device, which is used to execute any one of the above optional DC combiner box fire prevention control methods.
[0040] On the third aspect, the present application also provides a computer medium for storing a program for executing any one of the above-mentioned optional DC combiner box fire prevention control methods, which is composed of several modules, each of which executes a part of the program and cooperates with each other to realize the execution of the DC combiner box fire prevention control method.
[0041] According to the specific embodiments provided in this application, this application discloses the following technical effects:
[0042] The present application provides a fire prevention control method for a DC combiner box. The method continuously tracks the specific information of arc occurrence at various positions of the internal and external lines of the combiner box, uses the number and degree of arc occurrence as an indicator of electrical network performance degradation or aging, and then determines a fire occurrence assessment value. The fire occurrence assessment information represents the probability of fire occurrence. The larger the assessment value, the greater the probability of fire occurrence. In this way, the type and degree of arc generation can be discovered in time, the probability of fire occurrence can be comprehensively judged, and control operations can be made in a targeted manner to reduce the probability of fire risk. BRIEF DESCRIPTION OF THE DRAWINGS
[0043] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0044] Figure 1 The present invention is a schematic diagram of the execution flow of a DC combiner box fire prevention control method in one embodiment of the present application. DETAILED DESCRIPTION
[0045] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.
[0046] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.
[0047] As attached Figure 1 As shown, in an embodiment of the present invention, the present application provides a DC combiner box fire prevention control method, including: obtaining high-frequency sampling signals of voltage, current and temperature of each input channel of the DC combiner box;
[0048] The sampling signal characteristics are analyzed in real time to obtain the type and degree of the arc; the fire occurrence assessment value and location are determined based on the type and degree of the arc, and the switches inside and / or outside the DC combiner box are controlled based on the determination result to ensure the safety of the electrical network inside and / or outside the DC combiner box and avoid the occurrence of faults or fires; wherein the fire occurrence assessment value represents the probability of fire occurrence, and the larger the assessment value, the greater the probability of fire occurrence.
[0049] The sampling frequency of the high-frequency sampling signals for obtaining the voltage, current and temperature of each input channel of the DC combiner box shall not be less than 1kHz.
[0050] The sampling signal characteristics are analyzed in real time to obtain the type and degree of arc, including:
[0051] The voltage, current and temperature at the same time are used as the first sample data;
[0052] Establishing a relationship model between the electric arc and the first sample data as a first model, training the first model, and determining whether an electric arc occurs in the electrical network by using the first model;
[0053] Calculate harmonic information through voltage and current information;
[0054] When an arc occurs, the voltage, current, harmonics and temperature at the same time are used as the second sample data;
[0055] For arcs of different types and degrees, relationship models between the arc and the second sample data are respectively established as the second model, and the second model is trained to determine the type and degree of the arc through the second model.
[0056] In this embodiment, the first model and the second model adopt a feedforward neural network algorithm and an autoencoder algorithm respectively.
[0057] The training method of the first model includes:
[0058] Simulating arcs of different degrees multiple times at various locations of the electrical network inside and outside the combiner box, and obtaining first sample data at the time when the arc occurs and multiple consecutive times before and after the arc occurs;
[0059] The plurality of first sample data are randomly divided into a training set and a test set according to a certain ratio, so as to ensure that the training set and the test set at least include the first sample data obtained from the arc simulation test at each position, each type and each degree;
[0060] The first sample data in the training set is used as the model input information, and the judgment result of whether an arc occurs is used as the model output information to train the model;
[0061] The accuracy of the trained model output result is verified through the validation set. When the accuracy is higher than the set value, the first model training is completed. Otherwise, the multiple first sample data are reclassified and trained until the first model training is completed.
[0062] The training method of the second model includes:
[0063] Calculating a plurality of first sample data corresponding to the arc occurrence time in each simulation test to obtain corresponding harmonic information, thereby obtaining a plurality of second sample data;
[0064] The plurality of second sample data are randomly divided into a training set and a test set according to a certain ratio, so as to ensure that both the training set and the test set at least include the second sample data obtained from the arc simulation test at each position, each type and each degree;
[0065] The second sample data in the training set is used as the model input information, and the arc type and degree judgment result is used as the model output information to train the model;
[0066] The accuracy of the output results of the trained model is verified through the validation set. When the accuracy is higher than the set value, the second model training is completed. Otherwise, multiple second sample data are reclassified and trained until the second model training is completed.
[0067] Arc types include aging arc inside the box, fault arc inside the box, aging arc outside the box, and fault arc outside the box; the arc degree is any parameter or combination of parameters among arc duration, arc occurrence frequency, current data fluctuation value when arc occurs, and temperature data fluctuation value when arc occurs.
[0068] Fire assessment and location based on arc type and severity, including:
[0069] The fire occurrence assessment value is divided into a first assessment value and a second assessment value, the first assessment value corresponds to the fire occurrence assessment value inside the box, and the second assessment value corresponds to the fire occurrence assessment value outside the box; there are multiple first assessment values and second assessment values, which are divided according to the specific electrical line connection relationship, and different assessment values are calculated separately;
[0070] The arc degree is divided into N levels from low to high, where N is an integer greater than 0;
[0071] When the arc is an aging arc in the box, the arc degree corresponds to a level, and the first evaluation value is updated, where the updated first evaluation value = the first evaluation value before the update + N;
[0072] When the arc is a fault arc in the box, the arc degree is determined to correspond to a level, and the first evaluation value is updated, and the updated first evaluation value = the first evaluation value before the update + k*N; wherein k is a fault weighting coefficient, which is set according to experience or actual use requirements;
[0073] When the arc is an aging arc outside the box, the arc degree corresponds to the level, and the second evaluation value is updated, and the updated second evaluation value = the second evaluation value before the update + N;
[0074] When the arc is an external fault arc, the arc degree is determined to correspond to a level, and the second evaluation value is updated. The updated second evaluation value = the second evaluation value before the update + k*N; wherein k is a fault weighting coefficient, which is set based on experience or actual usage requirements.
[0075] Controlling switches inside and / or outside the DC combiner box according to the judgment result includes:
[0076] When the first evaluation value ≥ M1, the arc type corresponding to the last update of the first evaluation value is determined. If it is an aging arc in the box, the switch does not operate and only an alarm is issued; if it is a fault arc in the box, the switch inside the combiner box is controlled to be disconnected and an alarm is issued;
[0077] When the second evaluation value ≥ M2, determine the arc type corresponding to the last update of the second evaluation value. If it is an aging arc outside the box, the switch will not operate and only an alarm will be issued. If it is a fault arc outside the box, the switch corresponding to the line corresponding to the second evaluation value outside the junction box will be controlled to disconnect and an alarm will be issued.
[0078] By continuously tracking the specific information of arcs occurring at various locations inside and outside the combiner box, the number and degree of arcs are used as indicators of electrical network performance degradation or aging, and the fire occurrence assessment value is then determined. The fire occurrence assessment information represents the probability of fire. The larger the assessment value, the greater the probability of fire. In this way, the type and degree of arcs can be discovered in time, the probability of fire can be comprehensively judged, and targeted control operations can be made to issue early alarms to reduce the probability of fire risks.
[0079] In the prior art, when judging arc faults, only fault arcs and normal arcs are considered, while the damage to the electrical network caused by each normal arc is ignored. The more serious the arc is, such as the longer the duration or the larger the arc current, the more irreversible damage will be caused to the electrical line or part where the arc is generated, and over time, it will become a weak point in electrical performance. In addition, when the line is subjected to long-term influences such as air, water vapor, and temperature changes in a complex environment, the physical structure of the line changes, such as slow oxidation, resulting in a decrease in electrical insulation performance, and arcs are also easily generated. The frequency of arcs is getting higher and higher, and the corresponding degree is getting deeper and deeper, which can also indicate that the probability of fire is getting higher and higher.
[0080] In some existing technologies, arcs are monitored specifically, and the occurrence of arcs is accompanied by arc light and electromagnetic changes. Arc faults are judged and identified through photoelectric detection and / or magnetic sensing elements. This type of method can only monitor local locations, such as wiring terminals or electrical equipment in a confined space. It is difficult to fully and effectively detect faults or fire hazards in the entire electrical network.
[0081] The above scheme of the present application fully utilizes the characteristic conduction performance of voltage, current and temperature in the electrical network, and uses the comprehensive information of voltage, current and temperature to establish a model with the arc, thereby improving the scope of the electrical network for identifying faults or fire hazards.
[0082] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.
[0083] In an exemplary embodiment, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.
[0084] It should be noted that the data involved in this application (including but not limited to data used for analysis, data stored, data displayed, etc.) are all information and data fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.
[0085] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM may be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).
[0086] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0087] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.
Claims
1. A DC combiner box fire prevention control method, characterized in that: include: Obtain high-frequency sampling signals of voltage, current and temperature of each input channel of the DC combiner box; Analyze the sampling signal characteristics in real time to obtain the type and degree of arcing; Determine the fire assessment value and location based on the type and degree of the arc, and control the switches inside and / or outside the DC combiner box based on the determination result to ensure the safety of the electrical network inside and / or outside the DC combiner box and avoid the occurrence of faults or fires; The fire occurrence assessment value represents the probability of fire occurrence, and the larger the assessment value is, the greater the probability of fire occurrence is.
2. The DC combiner box fire prevention control method according to claim 1, characterized in that: The sampling frequency of the high-frequency sampling signals for obtaining the voltage, current and temperature of each input channel of the DC combiner box is not less than 1 kHz.
3. The DC combiner box fire prevention control method according to claim 1, characterized in that: The real-time analysis of the sampling signal characteristics to obtain the type and degree of the arc occurs includes: The voltage, current and temperature at the same time are used as the first sample data; Establishing a relationship model between the electric arc and the first sample data as a first model, training the first model, and determining whether an electric arc occurs in the electrical network by using the first model; Calculate harmonic information through voltage and current information; When an arc occurs, the voltage, current, harmonics and temperature at the same time are used as the second sample data; For arcs of different types and degrees, relationship models between the arc and the second sample data are respectively established as the second model, and the second model is trained to determine the type and degree of the arc through the second model.
4. The DC combiner box fire prevention control method according to claim 3, characterized in that: The training method of the first model includes: Simulating arcs of different degrees multiple times at various locations of the electrical network inside and outside the combiner box, and obtaining first sample data at the time when the arc occurs and multiple consecutive times before and after the arc occurs; The plurality of first sample data are randomly divided into a training set and a test set according to a certain ratio, so as to ensure that the training set and the test set at least include the first sample data obtained from the arc simulation test at each position, each type and each degree; The first sample data in the training set is used as the model input information, and the judgment result of whether an arc occurs is used as the model output information to train the model; The accuracy of the trained model output result is verified through the validation set. When the accuracy is higher than the set value, the first model training is completed. Otherwise, the multiple first sample data are reclassified and trained until the first model training is completed.
5. The DC combiner box fire prevention control method according to claim 4, characterized in that: The training method of the second model includes: Calculating a plurality of first sample data corresponding to the arc occurrence time in each simulation test to obtain corresponding harmonic information, thereby obtaining a plurality of second sample data; The plurality of second sample data are randomly divided into a training set and a test set according to a certain ratio, so as to ensure that both the training set and the test set at least include the second sample data obtained from the arc simulation test at each position, each type and each degree; The second sample data in the training set is used as the model input information, and the arc type and degree judgment result is used as the model output information to train the model; The accuracy of the output results of the trained model is verified through the validation set. When the accuracy is higher than the set value, the second model training is completed. Otherwise, multiple second sample data are reclassified and trained until the second model training is completed.
6. The DC combiner box fire prevention control method according to claim 4 or 5, characterized in that: The arc types include aging arc inside the box, fault arc inside the box, aging arc outside the box, and fault arc outside the box; the arc degree is any parameter or combination of parameters among the arc duration, arc occurrence frequency, current data fluctuation value when the arc occurs, and temperature data fluctuation value when the arc occurs.
7. The DC combiner box fire prevention control method according to claim 6, characterized in that: The fire occurrence assessment value and location determined according to the type and degree of the arc include: The fire occurrence assessment value is divided into a first assessment value and a second assessment value, the first assessment value corresponds to the fire occurrence assessment value inside the box, and the second assessment value corresponds to the fire occurrence assessment value outside the box; there are multiple first assessment values and second assessment values, which are divided according to the specific electrical line connection relationship, and different assessment values are calculated separately; The arc degree is divided into N levels from low to high, where N is an integer greater than 0; When the arc is an aging arc in the box, the arc degree corresponds to a level, and the first evaluation value is updated, where the updated first evaluation value = the first evaluation value before the update + N; When the arc is a fault arc in the box, the arc degree corresponds to a level, and the first evaluation value is updated, and the updated first evaluation value = the first evaluation value before the update + k*N; wherein k is a fault weighting coefficient, which is set according to experience or actual use requirements; When the arc is an aging arc outside the box, the arc degree corresponds to a level, and the second evaluation value is updated, where the updated second evaluation value = the second evaluation value before the update + N; When the arc is an external fault arc, the arc degree is determined to correspond to a level, and the second evaluation value is updated. The updated second evaluation value = the second evaluation value before the update + k*N; wherein k is a fault weighting coefficient, which is set based on experience or actual usage requirements.
8. The DC combiner box fire prevention control method according to claim 1, characterized in that: The controlling of switches inside and / or outside the DC combiner box according to the judgment result includes: When the first evaluation value ≥ M1, the arc type corresponding to the last update of the first evaluation value is determined. If it is an aging arc in the box, the switch does not operate and only an alarm is issued; if it is a fault arc in the box, the switch inside the combiner box is controlled to be disconnected and an alarm is issued; wherein M1 is set based on experience; When the second evaluation value ≥ M2, determine the arc type corresponding to the last update of the second evaluation value. If it is an aging arc outside the box, the switch will not operate and only an alarm will be issued. If it is a fault arc outside the box, the switch corresponding to the line corresponding to the second evaluation value outside the junction box will be controlled to disconnect and an alarm will be issued. Among them, M2 is set based on experience.
9. A DC combiner box fire protection control device, characterized in that Used to execute any one of the DC combiner box fire prevention control methods described in claims 1-8.
10. A computer medium, characterized in that Used to store a control program for executing any one of the DC combiner box fire prevention control methods described in claims 1-8, the medium is composed of a plurality of medium modules, and the plurality of medium modules each execute a part of the program, and implement the execution of the DC combiner box fire prevention control method alone or in cooperation with each other.