Fuse type selection method and system, storage medium and terminal

Abstract

The invention relates to the technical field of fuses, in particular to a fuse type selection method and system, a storage medium and a terminal. The method specifically comprises the following steps: a presetting step: establishing a fuse model taking a pre-arc Joule integral value as an action threshold value and setting constraint conditions of fuse model selection; a branch fuse type selection step: performing type selection on the branch fuses of the branches by adopting a mode of one-by-one short circuit and judging whether constraint conditions are met or not; and a busbar fuse type selection step: performing type selection on the branch fuse and the busbar fuse of each branch by adopting a mode of one-by-one short circuit and judging whether constraint conditions are met or not. Through the above design, a group of fuse models satisfying selectivity and economical efficiency can be effectively obtained, manual selection depending on experience is not needed, time and energy consumed by fuse model selection are greatly saved, and reliability of model selection is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of fuses, and in particular to a method and system for selecting a fuse, a storage medium, and a terminal. Background Art

[0002] As an electrical component with a simple operating principle, low manufacturing cost, and safe and reliable fault current interruption, the fuse plays an important role in overcurrent protection, especially short circuit protection.

[0003] However, traditional fuse selection mainly relies on manual calculation of electrical parameters, use of empirical formulas and specifications, reference to manufacturer's product manuals, and application characteristic curves. Although these methods can guide the selection of fuses to a certain extent, they often rely too much on experience and manual calculations, and it is difficult to ensure the reliability and economy of the selection at the same time. In addition, traditional methods tend to ignore the coupling between branches, resulting in failure to meet selectivity requirements, or because the safety margin left by the selection scheme is too large, causing unnecessary economic waste. In other words, the traditional fuse selection method has been difficult to meet the needs of modern systems in various fields for rapid fault response and efficient protection. Therefore, it is necessary to develop a more accurate and efficient selection method to deal with possible short-circuit faults and ensure the safe and stable operation of the system. Summary of the invention

[0004] In order to solve the above-mentioned shortcomings of the prior art that the selection of fuses is too dependent on experience and manual calculation, the present invention provides a method for selecting a fuse, comprising the following steps: A presetting step is to establish a fuse model with a pre-arc joule integral value as an action threshold and set constraints for fuse selection; A branch fuse selection step, based on the constraint conditions and the fuse model, the branch fuses of each branch are short-circuited one by one and judged whether they meet the constraint conditions; The busbar fuse selection step is to select the branch fuses and busbar fuses of each branch based on the constraints and the fuse model by short-circuiting them one by one and judging whether they meet the constraints; if they do not meet the constraints, the branch fuse model that does not meet the constraints the most times is replaced with a model with a larger pre-arc Joule integral value, and then the branch fuses are reselected based on the branch fuse selection step, and the steps of short-circuiting the branch fuses and busbar fuses of each branch one by one and judging whether they meet the constraints are repeated until the busbar fuse and the branch fuses of each branch meet the constraints, and the selection of the busbar fuses and branch fuses is completed.

[0005] In some embodiments, the fuse model with the pre-arc joule integral value as the action threshold is established based on any one of the Mayr model, the Cassie arc resistance theory model, the IEEE Std 1584 model, the ERAI model, the I2t model, and the Graham model.

[0006] In some embodiments, according to the fuse The characteristics verify the accuracy of the established fuse model and reduce the total Joule integral value error when the model blows by adjusting the parameters of the fuse model to obtain an accurate fuse model.

[0007] In some embodiments, the constraint condition includes at least one of the following: Constraint 1: Rated current value of the pre-selected fuse Greater than the current value of the branch under normal operating conditions ; Constraint 2: When a short circuit occurs, the pre-selected branch fuse of the faulty branch operates, and the branch fuse of the non-faulty branch does not operate; Constraint 3: When the branch fuse of the faulty branch is blown, the total short-circuit current of each non-faulty branch should be satisfied. Less than half of the pre-arcing Joule integral value of the pre-selected branch circuit fuse.

[0008] In some embodiments, in constraint 1, the rated current value of the pre-selected fuse is The current value of the branch under normal working conditions The expression between is: ; In the formula, is the ambient temperature coefficient, , is the heat dissipation condition coefficient, , is the safety margin factor, ; In constraint 3, the branch fuse of the faulty branch generates The expression of the relationship with time is: ; Then, the fuse of the non-fault branch must meet the following requirements: ; In the formula, Indicates a fault The short-circuit current flowing through the fuse at all times, Expressed as the pre-arcing Joule integral value of the pre-selected branch circuit fuse.

[0009] In some embodiments, based on the constraint conditions and the fuse model, short-circuiting the branch fuses located on the branch one by one to determine whether the branch fuse model meets the constraint conditions includes the following steps: Step S11, selecting the initial model of branch fuses satisfying constraint condition 1 on each branch according to constraint condition 1; Step S12, short-circuiting the other branches except the branch where the current pre-selected branch fuse is located one by one and obtaining the state of the current pre-selected branch fuse, and judging whether the current pre-selected branch fuse model satisfies both constraint condition 2 and constraint condition 3 according to the state of the current pre-selected branch fuse; Step S13, if the currently pre-selected branch fuse model satisfies both constraint 2 and constraint 3, the selection of the currently pre-selected branch fuse is completed; if the currently pre-selected branch fuse model does not satisfy both constraint 2 and constraint 3, the currently pre-selected branch fuse model is replaced with a model with a larger pre-arc Joule integral value, and step S12 is repeated until the currently pre-selected branch fuse model satisfies both constraint 2 and constraint 3; Step S14, short-circuit the currently pre-selected branch fuse model and obtain the branch fuse status of other branches, and then determine in turn whether the branch fuses of other branches simultaneously meet constraints 2 and constraints 3. If they do not simultaneously meet constraints 2 and constraints 3, the branch fuse that does not meet the constraints will be used as the new currently pre-selected branch fuse, and the new currently pre-selected branch fuse will be replaced with a model with a larger pre-arc Joule integral value; and repeat step S12 until all pre-selected branch fuse models simultaneously meet constraints 2 and constraints 3, and the selection of branch fuses is completed.

[0010] In some embodiments, selecting each busbar fuse on the busbar based on the constraint condition and the fuse model includes the following steps: Step S21, selecting N busbar fuse models that meet constraint condition 1 in the busbar according to constraint condition 1; Step S22: short-circuit each branch and busbar one by one according to the N busbar fuse models and obtain the status of each branch fuse and busbar fuse, and determine in turn whether each busbar fuse model and its corresponding branch fuse model simultaneously meet all constraints according to the status of each branch fuse and busbar fuse; Step S23, if the busbar fuse model and the branch fuse model meet all the constraints at the same time, the selection of the busbar fuse and the branch fuse is completed; if the branch fuse model and the busbar fuse model do not meet all the constraints at the same time, the branch fuse that does not meet the constraints the most times will be replaced with a model with a larger pre-arc Joule integral value, and the branch fuses will be reselected according to steps S12~S14, and then steps S21 and S22 are repeated to verify whether each busbar fuse model and the reselected branch fuses meet all the constraints at the same time. If all the constraints are met at the same time, the selection is completed. If not all the constraints are met at the same time, the branch fuses are reselected and steps S21 and S22 are repeated until the busbar fuse model and the branch fuses meet all the constraints at the same time, and the selection of the busbar fuse and the branch fuses is completed.

[0011] In a second aspect, the present invention further provides a fuse selection system, comprising: A presetting module, used to establish a fuse model with a pre-arcing joule integral value as an action threshold and set constraints for fuse selection; A branch fuse selection module, for selecting the branch fuses of each branch by short-circuiting them one by one and judging whether they meet the constraint conditions based on the constraint conditions and the fuse model; The busbar fuse selection module is used to select the branch fuses and busbar fuses of each branch based on the constraints and fuse model by short-circuiting them one by one and judging whether they meet the constraints; if they do not meet the constraints, the branch fuse model that does not meet the constraints the most times is replaced with a model with a larger pre-arc Joule integral value, and then the branch fuses are reselected based on the branch fuse selection steps, and the steps of short-circuiting the branch fuses and busbar fuses of each branch one by one and judging whether they meet the constraints are repeated until the busbar fuse and the branch fuses of each branch meet the constraints, and the selection of the busbar fuses and branch fuses is completed.

[0012] In a third aspect, the present invention further provides a storage medium, which is a non-volatile storage medium or a non-transient storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the fuse selection method described in the above embodiment is executed.

[0013] In a fourth aspect, the present invention further provides a terminal, comprising a memory and a processor, wherein the memory stores a computer program that can be run on the processor, and the processor executes the fuse selection method described in the above embodiment when running the computer program.

[0014] Based on the above, compared with the prior art, the fuse selection method provided by the present invention, through the design of preset steps, branch fuse selection steps and busbar fuse selection steps, can effectively obtain a group of fuse models that meet selectivity and economy by performing calculations and simulation analysis in a manner of first selecting branches and then selecting busbars. There is no need for manual selection based on experience, which greatly saves the time and energy spent on fuse selection and ensures the reliability of model selection.

[0015] Other features and beneficial effects of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other beneficial effects of the present invention can be realized and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. The positional relationships described in the drawings in the following description are based on the directions in which the components are drawn in the diagrams, unless otherwise specified.

[0017] Figure 1 A flowchart of the steps of a method for selecting a fuse provided in one embodiment of the present invention; Figure 2 A circuit schematic diagram of a Simulnk model of a Mayr arc model equivalent fuse provided by an embodiment of the present invention; Figure 3 A low voltage fuse provided by an embodiment of the present invention Characteristics verification circuit diagram; Figure 4 A logic program diagram for selecting a branch fuse provided by an embodiment of the present invention; Figure 5 A logic program diagram for selecting a busbar fuse according to an embodiment of the present invention; Figure 6 A structural block diagram of a fuse selection system provided by an embodiment of the present invention; Figure 7 A structural block diagram of a terminal provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments; the technical features designed in different implementation modes of the present invention described below can be combined with each other as long as they do not conflict with each other; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0019] In the description of the present invention, it should be noted that all terms (including technical terms and scientific terms) used in the present invention have the same meanings as those generally understood by ordinary technicians in the field to which the present invention belongs, and should not be understood as limitations on the present invention; it should be further understood that the terms used in the present invention should be understood to have the same meanings as these terms in the context of this specification and in the relevant fields, and should not be understood in an idealized or overly formal sense, unless explicitly defined in this invention.

[0020] In order to solve the shortcomings of the prior art that fuse selection is too dependent on experience and manual calculation, the present invention provides a fuse selection method. The technical solution of the present invention is described and illustrated in detail through various specific implementation methods in combination with different embodiments and drawings of the specification.

[0021] Embodiment 1 In this embodiment, the method for selecting a fuse includes the following steps: The presetting step is to establish a fuse model with the pre-arcing joule integral value as the action threshold and set the constraint conditions for the fuse selection.

[0022] Preferably, the fuse model with the pre-arc joule integral value as the action threshold may include but is not limited to any one of the Mayr model, the Cassie arc resistance theory model, the IEEE Std 1584 model, the ERAI model, the I2t model, and the Graham model. The selection is made according to actual needs, and this embodiment is not limited thereto.

[0023] Taking the fuse model based on Mayr arc model as an example, the arc conductance in the arcing stage and the accumulated heat per unit length of the arc column The relationship between them is: , where is a constant, Arc conductivity The energy required to change e = 2.718 times. In this formula, both sides of the equal sign are differentiated with respect to time, and because With arc voltage and arc current The relationship between , the arc characteristic differential equation of Mayr arc mathematical model can be expressed as: , where , is the time constant of the arc, is the arc static power loss, is the natural logarithm of the arc conductance. Based on the above arc characteristic differential equation, the Mayr arc model can be modeled using the differential equation editor (DEE) in Simulink to obtain the following: Figure 2 The circuit schematic diagram of the Mayr arc model equivalent fuse Simulnk model is shown. In DEE, the arc model differential equation is expressed as: ; In the formula, is the differential equation state variable; is the arc voltage , It is the signal that controls the action of the fuse. It has only two states: 1 and 0. When it changes from 0 to 1, it means that the Joule heat of the short-circuit current gathered in the fuse causes the fuse to operate; and They are the arc time constant and the arc column dissipated power respectively.

[0024] In addition, the constraints on fuse selection can be set according to the actual application field to ensure that the fuse model complies with national standards and relevant certification requirements, and this embodiment does not limit this. In general, when selecting the specifications of the fuse, technical parameter requirements such as setting the rated voltage, fuse rated current, fuse rated current and limit breaking capacity may be included. For example, for loads such as transformers, electric furnaces and lighting, the rated current of the fuse should be slightly greater than or equal to the load current; for power transmission and distribution lines, the rated current of the fuse should be slightly greater than or equal to the safety current of the line. Of course, the selection of fuses also includes but is not limited to short-circuit current limitation, fuse action time requirements, system voltage level compatibility and other aspects.

[0025] The branch fuse selection step is to select the branch fuses of each branch based on the constraint conditions and the fuse model by short-circuiting them one by one and judging whether they meet the constraint conditions.

[0026] Specifically, the short-circuit simulation of the branch fuses is performed one by one according to the fuse model, and the electrical parameters of each branch in the system are obtained according to the constraints. Based on the calculation or analysis of these electrical parameters, it is determined whether the branch fuse model meets the constraints. If not, the fuse model is replaced and the short-circuit simulation judgment is repeated until all branch fuses meet the constraints.

[0027] The busbar fuse selection step is to select the branch fuses and busbar fuses of each branch based on the constraints and the fuse model by short-circuiting them one by one and judging whether they meet the constraints; if they do not meet the constraints, the branch fuse model that does not meet the constraints the most times is replaced with a model with a larger pre-arc Joule integral value, and then the branch fuses are reselected based on the branch fuse selection step, and the steps of short-circuiting the branch fuses and busbar fuses of each branch one by one and judging whether they meet the constraints are repeated until the busbar fuse and the branch fuses of each branch meet the constraints, and the selection of the busbar fuses and branch fuses is completed.

[0028] This embodiment designs the preset steps, branch fuse selection steps, and busbar fuse selection steps. By performing calculations and simulation analyses by first selecting the branch and then the busbar, a group of fuse models that meet selectivity and economy can be effectively obtained. No manual selection based on experience is required, which greatly saves the time and effort spent on fuse selection and ensures the reliability of model selection.

[0029] Preferably, the presetting step further includes: The characteristics verify the accuracy of the established fuse model, and reduce the total Joule integral value error when the model blows by adjusting the parameters of the fuse model to obtain an accurate fuse model. Specifically, the established model can be used for simulation to obtain the blowing time and Joule integral value, and the simulated Joule integral value can be compared with the actual Joule integral value to obtain the total Joule integral value error. The simulated Joule integral value is made close to the actual Joule integral value through multiple verifications and parameter adjustments, thereby gradually reducing the total Joule integral value error when the model blows, and obtaining an accurate fuse model. Through the above steps, an accurate fuse model can be established to provide strong support for the design, selection and application of fuses.

[0030] Taking low-voltage fuses as an example, according to the relevant provisions mentioned in the national standards, the The verification method of the characteristics shall be based on Figure 3 The verification circuit diagram shown in the figure is used for verification. This verification mainly involves three parameters: power supply, , prospective short-circuit current And the time constant . Supply voltage is the rated voltage of the fuse. The current at which the arc energy is approximately the maximum during the test. And the time constant The resistance in the circuit With inductor There are the following relations: , ;like Figure 3 Verification circuit diagram, according to Kirchhoff's voltage law, the loop voltage equation can be obtained as: ; The pre-arcing Joule integral value of the fuse can be obtained by integrating the current in the circuit over time. It is expressed as: ;make The current value at this moment is , it is stipulated that The verification circuit is considered reasonable when the following equation is satisfied: That is, by solving the above formulas, we can get the expected short-circuit current in the verification circuit: And the time constant In this verification circuit, the Mayr arc model provided above is adjusted , and By adjusting the three parameters and gradually reducing the total Joule integral error when the model is blown, a more accurate Mayr arc fuse model can be obtained.

[0031] As an example, when the fuse selection method provided in this embodiment is applied to a ship power system, since the operating conditions of the ship are changeable and the selection of fuses on the busbar is closely related to the current operating conditions of each branch, during the fuse selection process, this embodiment gives priority to selecting the model of branch fuses and then selects the model of busbar fuses.

[0032] In addition, when the fuse selection method provided in this embodiment is applied to a ship power system, the selection constraints for the fuse can be formulated according to the national standard "Guidelines for Inspection of Ship DC Integrated Power Systems". The guideline mainly has the following requirements for fuse selection: (1) The rated current of the fast-acting fuse should be greater than any load current that may occur during operation; (2) The pre-arcing Joule integral value of the fast-acting fuse should meet the following requirements: When the fault branch fuse is blown, the total Joule integral value of the short-circuit current of each non-fault circuit should be less than half of the pre-arcing Joule integral value of its fast-acting fuse.

[0033] Based on the above, in this embodiment, the constraint condition preferably includes at least one of the following: Constraint 1: Rated current value of the pre-selected fuse Greater than the current value of the branch under normal operating conditions In constraint 1, when the fuse is in an environment with high temperature and poor heat dissipation conditions, its own operating current will decrease. Therefore, the rated current value of the pre-selected fuse The current value of the branch under normal working conditions The expression between is: ; In the formula, is the ambient temperature coefficient, , is the heat dissipation condition coefficient, , is the safety margin factor, Considering the actual situation in ship working conditions, this embodiment is preferred .

[0034] Constraint 2: When a short circuit occurs, the pre-selected branch fuse of the fault branch is actuated, and the branch fuse of the non-fault branch is not actuated. In specific implementation, based on the aforementioned signal for controlling the fuse action involved in the fuse model established based on the Mayr arc model, For example, the expression under constraint 2 should be: , .

[0035] Constraint 3: When the branch fuse of the faulty branch is blown, the total short-circuit current of each non-faulty branch should be satisfied. Less than half of the pre-arcing Joule integral value of the pre-selected branch fuse. In constraint 3, the voltage generated during the fuse melting process from the occurrence of the short circuit to the complete extinction of the arc between the fuses after the fault is cleared is The value of can be obtained from the product parameter table of the fuse, and the expression of this value and the total fusing time is: ; Then, the fuse of the non-fault branch must meet the following requirements: ; In the formula, Indicates a fault The short-circuit current flowing through the fuse at all times, Expressed as the pre-arcing Joule integral value of the pre-selected branch circuit fuse.

[0036] In an optional embodiment, the selection of branch fuses is a process of gradually matching the fuses on each branch. Therefore, based on the constraint conditions and the fuse model, the branch fuses on the branch are short-circuited one by one to determine whether the branch fuse model meets the constraint conditions, including the following steps: Step S11, selecting the initial model of branch fuses satisfying constraint condition 1 on each branch according to constraint condition 1; Step S12, short-circuiting the other branches except the branch where the current pre-selected branch fuse is located one by one and obtaining the state of the current pre-selected branch fuse, and judging whether the current pre-selected branch fuse model satisfies both constraint condition 2 and constraint condition 3 according to the state of the current pre-selected branch fuse; Step S13, if the currently pre-selected branch fuse model satisfies both constraint 2 and constraint 3, the selection of the currently pre-selected branch fuse is completed; if the currently pre-selected branch fuse model does not satisfy both constraint 2 and constraint 3, the currently pre-selected branch fuse model is replaced with a model with a larger pre-arc Joule integral value, and step S12 is repeated until the currently pre-selected branch fuse model satisfies both constraint 2 and constraint 3; Step S14, short-circuit the currently pre-selected branch fuse model and obtain the branch fuse status of other branches, and then determine in turn whether the branch fuses of other branches simultaneously meet constraints 2 and constraints 3. If they do not simultaneously meet constraints 2 and constraints 3, the branch fuse that does not meet the constraints will be used as the new currently pre-selected branch fuse, and the new currently pre-selected branch fuse will be replaced with a model with a larger pre-arc Joule integral value; and repeat step S12 until all pre-selected branch fuse models simultaneously meet constraints 2 and constraints 3, and the selection of branch fuses is completed.

[0037] As an example, when selecting a fuse on branch N in a system, the short-circuit fault is set to start from branch 1 and short-circuit to branch (N-1) in sequence, and determine whether the state of fuse No. N meets the constraint conditions at each short-circuit. If it does, a short-circuit fault occurs in branch N, and fuses No. 1 to (N-1) are checked one by one to see whether they match fuse No. N. If fuse No. x among fuses No. 1 to (N-1) does not match, fuse No. x is replaced and all fuse models from No. x to No. N are reselected until all selections are completed. Figure 4 The logical procedure diagram for branch circuit fuse selection is shown.

[0038] In another optional embodiment, when selecting a busbar fuse, the coordination with each branch must be considered. When the busbar fuse does not match the branch fuse, replacing the fuse model of the problematic branch or busbar alone often cannot achieve the goal due to the coupling of multiple branches. Therefore, when selecting the busbar fuse, this embodiment adopts the strategy of giving priority to replacing the busbar fuse model and replacing the branch fuse model in a targeted manner.

[0039] In the specific implementation, each busbar fuse on the busbar is selected based on the constraint conditions and the fuse model, including the following steps: Step S21, selecting N busbar fuse models that meet constraint condition 1 in the busbar according to constraint condition 1; Step S22: short-circuit each branch and busbar one by one according to the N busbar fuse models and obtain the status of each branch fuse and busbar fuse, and determine in turn whether each busbar fuse model and its corresponding branch fuse model simultaneously meet all constraints according to the status of each branch fuse and busbar fuse; Step S23, if the busbar fuse model and the branch fuse model meet all the constraints at the same time, the selection of the busbar fuse and the branch fuse is completed; if the branch fuse model and the busbar fuse model do not meet all the constraints at the same time, the branch fuse that does not meet the constraints the most times is replaced with a model with a larger pre-arc Joule integral value, and the branch fuses are reselected according to steps S12~S14, and then steps S21 and S22 are repeated to verify whether each busbar fuse model and the reselected branch fuses meet all the constraints at the same time. If all the constraints are met at the same time, the selection is completed. If not all the constraints are met at the same time, the branch fuses are reselected and steps S21 and S22 are repeated until the busbar fuse model and the branch fuses meet all the constraints at the same time, and the selection of the busbar fuse and the branch fuses is completed.

[0040] As an example, in this embodiment, after finding several busbar fuse models that meet the conditions according to constraint condition 1, each busbar fuse model can be verified individually one by one according to the rated current value from large to small. During the verification process, each branch short-circuit point and the busbar short-circuit point are short-circuited in turn. The status of each fuse is recorded after each short-circuit, and it is judged whether it meets the requirements according to the constraints. Branches that do not meet the conditions are not matched with the current model of busbar fuse. Assuming that each model of busbar fuse verifies several problem branches in the short-circuit experiment, find the branch fuse with the most problems, replace it with a model with a larger pre-arc Joule integral value, and re-select a group of new branch fuse models according to the branch selection procedure, and verify the matching degree with the busbar fuse again until a group of models that meet the conditions are selected, and the selection of the entire system can be completed. For example Figure 5 The logic program diagram of busbar fuse selection is shown. In particular, this embodiment can be effectively applied to the selection of fuses for ship DC switchboards.

[0041] Embodiment 2 See also Figure 6 The embodiment of the present invention further provides a fuse selection system, comprising at least: A presetting module, used to establish a fuse model with a pre-arcing Joule integral value as an action threshold and set constraints for fuse selection; A branch fuse selection module, for selecting the branch fuses of each branch by short-circuiting them one by one and judging whether they meet the constraint conditions based on the constraint conditions and the fuse model; The busbar fuse selection module is used to select the branch fuses and busbar fuses of each branch based on the constraints and fuse model by short-circuiting them one by one and judging whether they meet the constraints; if they do not meet the constraints, the branch fuse model that does not meet the constraints the most times is replaced with a model with a larger pre-arc Joule integral value, and then the branch fuses are reselected based on the branch fuse selection steps, and the steps of short-circuiting the branch fuses and busbar fuses of each branch one by one and judging whether they meet the constraints are repeated until the busbar fuse and the branch fuses of each branch meet the constraints, and the selection of the busbar fuses and branch fuses is completed.

[0042] The system can not only effectively shorten the time used for fuse selection, but also obtain a set of fuse solutions that meet the selective protection requirements of the application system and are more economical according to program calculation and simulation analysis. The shortcomings of the traditional selection method that cannot take into account both reliable selectivity and economy are solved. Regarding the modules in the above embodiment, the specific way in which each module performs the operation has been described in detail in the embodiment of the method, and will not be elaborated here.

[0043] Embodiment 3 An embodiment of the present invention further provides a storage medium, which is a non-volatile storage medium or a non-transient storage medium, on which a computer program is stored. When the computer program is executed by a processor, the fuse selection method described in any of the above embodiments is executed.

[0044] In a specific implementation, the storage medium is a magnetic disk, an optical disk, a read-only memory (ROM), a random access memory (RAM), a flash memory (Flash Memory), a hard disk (Hard Disk Drive, abbreviated as: HDD) or a solid-state drive (SSD), etc.; the storage medium may also include a combination of the above types of memory.

[0045] Embodiment 4 See also Figure 7 An embodiment of the present invention further provides a terminal, the terminal comprising a memory and a processor, the memory storing a computer program that can be run on the processor, and the processor executing the fuse selection method described in any of the above embodiments when running the computer program.

[0046] In specific implementation, the number of processors may be one or more, and the processor may be a central processing unit (CPU). The processor may also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components and other chips, or a combination of the above-mentioned chips. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0047] The memory and the processor may be communicatively connected via a bus or other means, and the memory stores program instructions executable by at least one processor, and the program instructions are executed by at least one processor so that the processor executes the fuse selection method described in any of the above embodiments.

[0048] In summary, the fuse selection method and system provided by the present invention is based on the Mayr arc model, and a general model of a fuse with the pre-arc Joule integral value as the action threshold is established. A test circuit is built according to the requirements for low-voltage fuses in the national standard, and the accuracy of the fuse model is verified based on the melting Joule integral value. At the same time, based on the provisions of the "Guidelines for Inspection of Ship DC Integrated Power Systems", a fuse selection scheme is proposed. By selecting the branch first and then the busbar, based on a more accurate fuse model, calculations are performed on the Matlab / Simulink platform, and finally a set of fuse models that meet both selectivity and economy are obtained. There is no need for manual selection based on experience, which greatly saves the time and energy spent on fuse selection and ensures the reliability of model selection.

[0049] In addition, those skilled in the art should understand that, although there are many problems in the prior art, each embodiment or technical solution of the present invention can be improved in only one or several aspects, without having to solve all the technical problems listed in the prior art or background technology at the same time. Those skilled in the art should understand that the content not mentioned in a claim should not be used as a limitation on the claim.

[0050] Although the terms such as preset steps, constraints, fuse models, branch fuse selection steps, busbar fuse selection steps, etc. are used more frequently in this article, the possibility of using other terms is not excluded. These terms are used only to more conveniently describe and explain the essence of the present invention; interpreting them as any additional restrictions is contrary to the spirit of the present invention; the terms "first", "second", etc. (if any) in the description and claims of the embodiments of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for selecting a fuse, characterized in that: The following steps are involved: A presetting step is to establish a fuse model with a pre-arc joule integral value as an action threshold and set constraints for fuse selection; A branch fuse selection step, based on the constraint conditions and the fuse model, the branch fuses of each branch are short-circuited one by one and judged whether they meet the constraint conditions; The busbar fuse selection step is to select the branch fuses and busbar fuses of each branch based on the constraints and the fuse model by short-circuiting them one by one and judging whether they meet the constraints; if they do not meet the constraints, the branch fuse model that does not meet the constraints the most times is replaced with a model with a larger pre-arc Joule integral value, and then the branch fuses are reselected based on the branch fuse selection step, and the steps of short-circuiting the branch fuses and busbar fuses of each branch one by one and judging whether they meet the constraints are repeated until the busbar fuse and the branch fuses of each branch meet the constraints, and the selection of the busbar fuses and branch fuses is completed.

2. The method for selecting a fuse according to claim 1, characterized in that: The fuse model with the pre-arc joule integral value as the action threshold is established based on any one of the Mayr model, the Cassie arc resistance theory model, the IEEE Std 1584 model, the ERAI model, the I2t model, and the Graham model.

3. The method for selecting a fuse according to claim 1, characterized in that: The presetting step also includes: The characteristics verify the accuracy of the established fuse model and reduce the total Joule integral value error when the model blows by adjusting the parameters of the fuse model to obtain an accurate fuse model.

4. The method for selecting a fuse according to claim 3, characterized in that: The constraint condition includes at least one of the following: Constraint 1: Rated current value of the pre-selected fuse Greater than the current value of the branch under normal operating conditions ; Constraint 2: When a short circuit occurs, the pre-selected branch fuse of the faulty branch operates, and the branch fuse of the non-faulty branch does not operate; Constraint 3: When the branch fuse of the faulty branch is blown, the total short-circuit current of each non-faulty branch should be satisfied. Less than half of the pre-arcing Joule integral value of the pre-selected branch circuit fuse.

5. The method for selecting a fuse according to claim 4, characterized in that: In constraint 1, the rated current value of the pre-selected fuse is The current value of the branch under normal working conditions The expression between is: ; In the formula, is the ambient temperature coefficient, , is the heat dissipation condition coefficient, , is the safety margin factor, ; In constraint 3, the branch fuse of the faulty branch generates The expression of the relationship with time is: ; Then, the fuse of the non-fault branch must meet the following requirements: ; In the formula, Indicates a fault The short-circuit current flowing through the fuse at all times, Expressed as the pre-arcing Joule integral value of the pre-selected branch circuit fuse.

6. The method for selecting a fuse according to claim 4, characterized in that: Based on the constraint conditions and the fuse model, the branch fuses located on the branch are short-circuited one by one to determine whether the branch fuse model meets the constraint conditions, including the following steps: Step S11, selecting the initial model of branch fuses satisfying constraint condition 1 on each branch according to constraint condition 1; Step S12, short-circuiting the other branches except the branch where the current pre-selected branch fuse is located one by one and obtaining the state of the current pre-selected branch fuse, and judging whether the current pre-selected branch fuse model satisfies both constraint condition 2 and constraint condition 3 according to the state of the current pre-selected branch fuse; Step S13, if the currently pre-selected branch fuse model satisfies both constraint 2 and constraint 3, the selection of the currently pre-selected branch fuse is completed; if the currently pre-selected branch fuse model does not satisfy both constraint 2 and constraint 3, the currently pre-selected branch fuse model is replaced with a model with a larger pre-arc Joule integral value, and step S12 is repeated until the currently pre-selected branch fuse model satisfies both constraint 2 and constraint 3; Step S14, short-circuit the currently pre-selected branch fuse model and obtain the branch fuse status of other branches, and then determine in turn whether the branch fuses of other branches simultaneously meet constraints 2 and constraints 3. If they do not simultaneously meet constraints 2 and constraints 3, the branch fuse that does not meet the constraints will be used as the new currently pre-selected branch fuse, and the new currently pre-selected branch fuse will be replaced with a model with a larger pre-arc Joule integral value; and repeat step S12 until all pre-selected branch fuse models simultaneously meet constraints 2 and constraints 3, and the selection of branch fuses is completed.

7. The method for selecting a fuse according to claim 6, characterized in that: The selection of each busbar fuse on the busbar is carried out based on the constraint conditions and the fuse model, including the following steps: Step S21, selecting N busbar fuse models that meet constraint condition 1 in the busbar according to constraint condition 1; Step S22: short-circuit each branch and busbar one by one according to the N busbar fuse models and obtain the status of each branch fuse and busbar fuse, and determine in turn whether each busbar fuse model and its corresponding branch fuse model simultaneously meet all constraints according to the status of each branch fuse and busbar fuse; Step S23, if the busbar fuse model and the branch fuse model meet all the constraints at the same time, the selection of the busbar fuse and the branch fuse is completed; if the branch fuse model and the busbar fuse model do not meet all the constraints at the same time, the branch fuse that does not meet the constraints the most times will be replaced with a model with a larger pre-arc Joule integral value, and the branch fuses will be reselected according to steps S12~S14, and then steps S21 and S22 are repeated to verify whether each busbar fuse model and the reselected branch fuses meet all the constraints at the same time. If all the constraints are met at the same time, the selection is completed. If not all the constraints are met at the same time, the branch fuses are reselected and steps S21 and S22 are repeated until the busbar fuse model and the branch fuses meet all the constraints at the same time, and the selection of the busbar fuse and the branch fuses is completed.

8. A fuse selection system, characterized in that: include: A presetting module, used to establish a fuse model with a pre-arcing Joule integral value as an action threshold and set constraints for fuse selection; A branch fuse selection module, for selecting the branch fuses of each branch by short-circuiting them one by one and judging whether they meet the constraint conditions based on the constraint conditions and the fuse model; The busbar fuse selection module is used to select the branch fuses and busbar fuses of each branch based on the constraints and fuse model by short-circuiting them one by one and judging whether they meet the constraints; if they do not meet the constraints, the branch fuse model that does not meet the constraints the most times is replaced with a model with a larger pre-arc Joule integral value, and then the branch fuses are reselected based on the branch fuse selection steps, and the steps of short-circuiting the branch fuses and busbar fuses of each branch one by one and judging whether they meet the constraints are repeated until the busbar fuse and the branch fuses of each branch meet the constraints, and the selection of the busbar fuses and branch fuses is completed.

9. A storage medium, characterized in that: The storage medium is a non-volatile storage medium or a non-transient storage medium, on which a computer program is stored. When the computer program is executed by a processor, the method for selecting a fuse according to any one of claims 1 to 7 is executed.

10. A terminal, characterized in that: The method comprises a memory and a processor, wherein the memory stores a computer program that can be run on the processor, and the processor executes the fuse selection method according to any one of claims 1 to 7 when running the computer program.

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