75 results about "Arc model" patented technology

The invention relates to the technical field of composite material lightning protection, in particular to a pyrolytic dynamics simulation analysis method for lightning stroke damage of a carbon fiber composite material. According to the technical scheme, the method comprises the following steps that a new model is established in ABAQUS / CAE, a carbon fiber composite material is established, a laminated plate laying layer is defined, a multi-physical field analysis step is set, load current density is applied to a lightning stroke action area, the pyrolysis behavior of the carbon fiber composite material under lightning stroke high Joule heat is simulated based on a pyrolysis kinetic model, and operation is established in a Job module. And parallel computing parameters are selected and submitted for solution, temperature field distribution is checked, and the current density diffusion trend is verified. Through the electric-thermal-structure coupling model, the conductivity gradient design and the lightning arc model, refined prediction of CFRP lightning stroke damage is achieved, the damage area is reduced, the lightning stroke process is accurately simulated, and the adaptation and protection effects on the lightning stroke environment are improved.

The invention discloses a modeling method and system for a vehicle network field circuit coupling model under a contact line short-circuit working condition, and relates to the technical field of modeling, and the method comprises the following steps: constructing a short-circuit arc equivalent model under the contact line short-circuit working condition based on an isolation switch equivalent model, one end of the short-circuit arc equivalent model is connected with a contact line in sliding connection with a pantograph in the chain type lumped tau-shaped network model through a switch element, the other end of the short-circuit arc equivalent model is connected with a steel rail in the chain type lumped tau-shaped network model, and a vehicle network circuit model under the contact line short-circuit working condition is obtained; and taking the short-circuit arc current at any short-circuit phase obtained through simulation of the vehicle network circuit model as a current excitation source of the three-dimensional model, and obtaining a vehicle network field model under the contact line short-circuit working condition. The rise rate, peak value and attenuation process of the short-circuit current can be accurately simulated by adding the short-circuit arc, the arc voltage drop is reflected, and the authenticity and practicability of simulation are remarkably improved.

The invention discloses a method and system for simulating a latent fault of a medium-voltage distribution cable. The method comprises the following steps: establishing a target cable latent fault model based on an arc model; according to the target cable latent fault model, establishing a first simulation model, and obtaining a first fault simulation waveform; according to the first fault simulation waveform, obtaining a relationship between the target parameter and a fault feature in a target cable latent fault model; and obtaining an optimal target parameter to determine a final target cable latent fault model. By simulating a cable latent fault, the potential problem of the cable can be predicted and identified more accurately, so that a maintenance measure is taken in advance, and occurrence of a sudden fault is avoided. By optimizing the target parameters, it can be ensured that the simulation result is highly consistent with the waveform feature of the actual cable latent fault, and therefore the effectiveness of fault prevention and protection measures is improved.

The invention provides a ship direct current distribution board fuse setting method considering on-off arcing. Establishing a fuse breaking arcing model: describing a fuse arcing process based on a Cassie arc model, fitting test data through a genetic algorithm to establish a model parameter change rule, and establishing a relationship between a test loop resistance value and an arc voltage constant and an arc time constant through a BP neural network; the method comprises the following steps: calculating equivalent short-circuit impedance of a fault branch, and calculating a test loop impedance parameter which can be equivalent to a system short-circuit fault current waveform according to a short-circuit current peak proportional relation of a system and a test loop; and executing constraint driving type fuse setting: taking the condition that the rated current of the fuse is not less than the product of a safety margin coefficient and the maximum continuous working current of the branch and the total Joule integral value of the non-fault branch does not exceed 50% of the pre-arc Joule integral value as constraint conditions, and adopting a minimum pre-arc Joule integral value priority strategy, iteratively selecting the model from the minimum-scale branch group and expanding to a whole-system branch.

The invention discloses an RC-IGCT-based superconducting hybrid DC circuit breaker, and relates to the topological structure and working principle analysis of DC circuit breakers. The circuit topology comprises two parts: (1) a resistance-type superconducting fault current limiter R-SFCL and a UDS isolation switch adopting a TP KEMA arc model are connected in series, and (2) a current commutation component composed of diodes VD1-VD4, a current injection branch and a current commutation branch. VD1-VD4 are used for conducting bidirectional current; the current injection branch comprises a pre-charging capacitor C, an inductor L and a thyristor T which are connected in series; the current commutation branch circuit is formed by connecting a power electronic switch, an RCD buffer branch circuit and an energy absorption branch circuit in parallel, and the energy absorption branch circuit is composed of a metal oxide lightning arrester; the invention further discloses a current breaking method of the superconducting hybrid direct-current circuit breaker. According to the invention, quick switching-off can be realized after fault current occurs, the rise rate of the fault current is limited, and the loss and the cost are low under the normal through-current condition.

The invention relates to a high-voltage SF6 circuit breaker asymmetric short-circuit current breaking result prediction method, equipment and a medium. The method comprises the following steps: acquiring a plurality of groups of arc voltage and arc current test data obtained by performing a T100a test on a target circuit breaker under a first time constant; based on the test data, establishing a black box arc model, and fitting to obtain arc dissipation power and arc time constant corresponding to each group of test data through numerical solution and parameter optimization algorithms, thereby obtaining an on-off critical value; fitting is carried out in an arc breaking critical parameter fitting model, and values of a first parameter, a second parameter, a third parameter and a fourth parameter are determined; and obtaining a predicted value of an on-off value under the working condition through an arc on-off critical parameter fitting model, if the predicted value is greater than an on-off critical value, determining that on-off is successful, otherwise, determining that on-off is failed. Compared with the prior art, the method has the advantages of high accuracy, high practicability, simple process and the like.

The present invention discloses a cable status assessment method, device, and non-volatile storage medium. The method comprises: constructing a fault arc model and a line model corresponding to a target cable; generating a simulation waveform based on the fault arc model and the line model; determining target fault parameters based on the measured waveform and the simulation waveform at the fault point in the target cable, wherein the target fault parameters represent indicator data describing the fault characteristics and status; determining the waveform characteristics of the fault point based on the target fault parameters; and determining the target cable status assessment result based on the waveform characteristics. The present invention solves the current technical problem of difficulty in sensitively capturing and accurately assessing early-stage faults in cable equipment, particularly transient fault characteristics, resulting in inaccurate cable assessments.

The invention provides a current and voltage characteristic generation method and device of a transient arc, which can be used in the technical field of power system relay protection, and the method comprises the steps: constructing an arc model through employing an external electromotive force source, an internal resistor, and a plasma with a preset radius, length and transient temperature; generating an energy conservation model and a current model according to the arc model; converting the energy conservation model to obtain a direct current arc temperature model; and utilizing the direct current arc temperature model, the current model and a pre-generated conductivity regression model to generate current and voltage characteristics of the arc. According to the method and device for generating the current and voltage characteristics of the transient arc, the non-transient stable change process of the temperature and the voltage drop of the arc column is obtained, the change process of the arc column is described more accurately, and research on the grounding fault arc resistance of a power distribution network is facilitated.

The application discloses a high-speed railway pantograph-catenary arc electromagnetic radiation interference modeling analysis method, constructs a pantograph-catenary arc-pantograph power supply system integrated model containing a traction substation model, a traction network model, a train traction transmission system model, a train-track return current grounding system model and a pantograph-catenary arc model; under a pantograph-off arc transient condition, arc current is obtained through simulation calculation; and based on the arc current, a relationship between arc radiation power and spatial equivalent electric field intensity is established to represent the influence of time-varying characteristics of traction network electrical parameters on pantograph-catenary arc electromagnetic radiation interference. Under the pantograph-off arc transient condition, the real-time changes of impedance and capacitive reactance parameters of the traction network are involved in the unified solution of arc current formation, radiation power evolution and spatial electric field intensity calculation, and meanwhile, key coupling factors of the train high-voltage system and the train-track grounding system are mainly considered, so that the accuracy and engineering applicability of pantograph-catenary arc electromagnetic radiation interference analysis are improved.

The invention discloses a molded case circuit breaker on-off process dynamic simulation method based on a heterogeneous simulation system, and relates to the technical field of low-voltage electric appliance design and simulation. Loop current calculated by the first simulation subsystem is transmitted to the second simulation subsystem in real time and used for calculating electromagnetic force for driving a mechanism to move, and contact displacement generated by mechanism movement is immediately fed back to the first subsystem and used for dynamically updating resistance characteristics of an arc model, so that calculation of arc voltage is affected, and the simulation effect is achieved. The arc voltage is directly fed back to the circuit model to determine the current value at the next moment, so that a simulation chain for complete dynamic interaction of the circuit current, the electromagnetic force, the mechanical displacement, the arc resistance, the arc voltage and the circuit current is formed; therefore, the simulation model can reflect the dynamic evolution process of each physical quantity in the real on-off process in a self-consistent manner.

The invention provides a method and system for suppressing arc grounding overvoltage, and the method comprises the steps: obtaining a ground capacitance value of a power grid system in a normal operation state, and adjusting the inductance value of an arc suppression coil through the ground capacitance value, so as to enable the power grid system to be separated from a resonance region; monitoring and recording arc current data of the power grid system when the arc grounding fault occurs through an optical transformer, and performing spectral analysis on the arc current data to obtain a high-frequency component of the arc current data; and according to the high-frequency component, an adjustment strategy is obtained through analysis of an arc model constructed by using arc characteristics, and according to the adjustment strategy, the inductance value of the arc suppression coil is adjusted to perform full compensation so as to offset the arc current.

The invention provides a cable local insulation breakdown semi-stable arc modeling method and device and electronic equipment. The method comprises the following steps: acquiring a transient oscillation arc waveform based on a periodic pulse function in a cable; acquiring a steady-state breakdown arc waveform based on an arc gap energy balance equation in the cable; calculating the switching time of the transient oscillation arc waveform and the steady-state breakdown arc waveform according to the breakdown voltage of the insulating layer of the cable; combining the transient oscillation arc waveform and the steady-state breakdown arc waveform according to the switching time to obtain a semi-steady-state arc waveform; the semi-stable arc waveform is used to describe arc conductance at different moments in time. According to the method, the semi-stable arc model for describing the local insulation breakdown process of the cable is established, so that the defects that an existing model is poor in interpretability and parameters are difficult to set can be overcome, a theoretical basis is provided for research on early fault early warning and fault identification of the cable, and the distribution network accident risk and the line hidden danger are reduced.

The present invention provides a fuse setting method for a ship's DC distribution board that takes arcing into account. A fuse breaking arcing model is established: the fuse arcing process is described based on the Cassie arc model. The model parameter variation pattern is established by fitting test data using a genetic algorithm. A BP neural network is used to construct the relationship between the test loop resistance value and the arc voltage constant and arc time constant. The equivalent short-circuit impedance of the fault branch is calculated, and based on the proportional relationship between the short-circuit current peaks of the system and the test loop, the test loop impedance parameters that can be equivalent to the system short-circuit fault current waveform are calculated. Constraint-driven fuse setting is performed: with the constraints that the fuse rated current is not less than the product of the safety margin factor and the branch's maximum continuous operating current, and that the total joule integral value of the non-fault branch does not exceed 50% of its pre-arcing joule integral value, a minimum pre-arcing joule integral value priority strategy is adopted. Iterative selection begins with the smallest branch group and expands to all system branches.

The invention relates to a direct-current fault arc simulation method and device, a storage medium and a program product. The method comprises the steps that an initial current signal is generated through a direct current module according to power generation parameters; performing arc simulation on the initial current signal flowing through the arc model through the arc model, and outputting a target current signal after the DC fault arc phenomenon occurs; performing frequency domain conversion on the target current signal to obtain a target spectrogram corresponding to the target current signal; and determining fault arc information corresponding to the DC fault arc phenomenon based on the target spectrogram. By adopting the method, accurate analysis of the fault arc can be realized.

1. Name of the design product: Movable storage locker (Upark series space model). 2. Use of the design product: For office storage, household storage, and as a stool for use beside a table. 3. Design key points of the design product: Lies in the shape. 4. Picture or photo that best shows the design key points: 3D view 1 of Design 1. 5. Designate Design 1 as the basic design. 6. Other situations that need to be explained: Other explanations: Design 1 is a movable storage locker (Upark series space arc model); Design 2 is a movable storage locker (Upark series space section model).

A method for characterizing single-phase grounding faults in a distribution network that takes into account nonlinear arc resistance includes: constructing a discretized computer simulation model of the arc model; determining fault arc model parameters for the discretized computer simulation model constructed under different conditions based on measured data of arcs generated when a distribution conductor passes through concrete, asphalt pads, gravel patches, or grassy areas when a single-phase grounding fault occurs; inputting the fault arc model parameters into the discretized computer simulation model of the arc model, integrating them with the normal operation model of the distribution network to form a discretized computer simulation model of the distribution network single-phase grounding fault; and performing characterization analysis of the distribution network single-phase grounding fault characteristics including nonlinear arc resistance based on zero-sequence current harmonic extraction and distortion analysis. The present invention implements electromagnetic transient simulation of arc faults occurring on distribution lines on grass, gravel, concrete, asphalt roads, or trees, meeting the needs of arc fault detection for single-phase grounding faults in distribution networks.

1. Name of the Design Product: Flushing Panel (Micro-arc Model). 2. Use of the Design Product: Used to control sanitary ware equipment. 3. Design Key Points of the Design Product: Lies in the shape. 4. Picture or Photo Most Indicating the Design Key Points: Stereogram.

The invention provides a distributed power supply series-parallel power distribution network fault identification model construction method and system, and the method comprises the steps: constructing a series-parallel simulation power distribution network based on preset power distribution network simulation information, and constructing a distributed energy simulation system based on preset distributed energy structure information; connecting the distributed energy simulation system to the series-parallel simulation power distribution network, performing single-phase earth fault simulation on the series-parallel simulation power distribution network by using the arc model, and collecting a fault transient current simulation signal of the series-parallel simulation power distribution network; performing feature extraction on the fault transient current simulation signal by combining a wavelet transform method to obtain a fault signal training feature, determining a fault recognition result based on the fault signal training feature, and further taking the fault signal training feature as an input and the fault recognition result corresponding to the fault signal training feature as an output to obtain a fault recognition result; and training the fault identification model to obtain a trained fault identification model, thereby realizing accurate identification of the fault of the hybrid power distribution network containing the distributed power supply through the fault identification model.

The invention relates to a method and a device for establishing a single-phase earth fault arc model. The method comprises the following steps: collecting arc data and load data in an arc stage, and establishing an arc model according to the arc data and the load data: for an arc starting stage, obtaining arc starting resistance according to arc current, arc voltage, load current and load voltage in the arc starting stage; for the steady-state arcing stage, arcing resistance is obtained according to the arc current, the arc voltage, the load current and the load voltage of the steady-state arcing stage; and for the arc quenching stage, obtaining the arc quenching resistance according to the arc current, the arc voltage, the load current and the load voltage in the arc quenching stage. According to the method, the arc models are established in stages from the arc starting stage, the steady-state arcing stage and the arc extinguishing stage, so that the arc model of each arc stage better conforms to the arc characteristics of each stage, and the actual single-phase earth fault arc can be better simulated.

The embodiment of the invention discloses a power distribution network arc simulation method and device, and the method comprises the steps: obtaining a preset expression of an arc model, the expressions comprise a first expression and a second expression, the first expression is obtained based on a Mayr electric arc model and used for describing the relation between the change rate of the electric arc conductance g along with time and the time characteristic tau and the relation between the electric arc conductance g and the static conductance G, the second expression is used for describing the relation between the time characteristic tau and the absolute value i of the electric arc current, and the second expression is in the form of a logarithmic function; parameter values of parameters in the expressions of the arc model are obtained through experimental measurement of the power distribution network, and the parameters comprise parameters in the second expression; substituting the parameter value of each parameter into the expression of the arc model to obtain the arc model; and performing power distribution network arc simulation based on the arc model. According to the invention, the accuracy of power distribution network arc simulation can be improved.

The application discloses a multi-feature fusion-based arc model discrimination method and device and a medium, relates to the field of fault arc detection, and aims to solve the problem of misjudgment in arc discrimination. The parameter region is based on an arc current signal, and dimensioned features and dimensionless features at different frequencies are extracted. The dimensioned features and the dimensionless features at different frequencies are respectively input into a convolutional neural network for training after feature fusion. The dimensioned features and the dimensionless features after fusion are input into the convolutional neural network for training after feature fusion, and a fusion result is obtained to determine whether an arc exists. The high-frequency features (dimensionless features and dimensioned features) at different frequencies are combined, feature fusion is performed in the convolutional neural network layer training process, different feature characteristics are analyzed and obtained from different angles, the diversity and comprehensiveness of the features are reasonably improved, the influence of low-frequency interference in the environment on discrimination is greatly reduced, and the misjudgment rate can be obviously improved.

The application discloses a method, device, equipment and medium for determining an anode sheath length of an arc model. The method comprises the following steps: in the first step, a first arc root radius is determined according to a current density output by a first arc generation model; in the second step, a second arc root radius is determined according to the first arc root radius and a second arc generation model, wherein an input parameter of the second arc generation model comprises a first anode sheath length; and in the third step, the anode sheath length is determined according to the first arc root radius and the second arc root radius. By determining the anode sheath length, the application is beneficial to solving the problem of slow solving speed and non-convergence of arc model simulation calculation, thereby being beneficial to establishing a more accurate arc simulation model.

1. Name of the Design Product: Ice Cream Machine (Arc Model). 2. Use of the Design Product: To make ice cream machines. 3. Design Key Points of the Design Product: Lies in the shape. 4. Picture or Photo Most Indicating the Design Key Points: Perspective view.

The invention relates to the technical field of carbon brush grinding, and discloses a carbon brush precision grinding device which comprises a swing grinding mechanism, a guide dust collection mechanism is arranged at the bottom of the swing grinding mechanism, an X-axis adjusting mechanism is movably arranged on the surface of the guide dust collection mechanism, and a Y-axis adjusting mechanism is arranged at the top of the X-axis adjusting mechanism. And a carbon brush clamping mechanism is arranged at the top of the Y-axis adjusting mechanism. According to the precise grinding device for the carbon brush, through the arrangement of the swing grinding mechanism, the guide dust collection mechanism, the X-axis adjusting mechanism, the Y-axis adjusting mechanism and the carbon brush clamping mechanism, a needed arc model can be simulated through the swing grinding mechanism in the using process, and the precise grinding device is suitable for sliding rings and carbon brushes of different sizes through adjustment of the swing grinding mechanism; compared with a traditional device, the size is reduced, and the grinding efficiency is improved.

The invention relates to the technical field of contact simulation, and provides a contact surface erosion simulation analysis method based on a three-dimensional electric arc, which comprises the following steps: modeling according to the shape of a contact and a modeling area to obtain a three-dimensional electric arc model, determining an electric arc function and a contact movement function in the three-dimensional electric arc model, and performing multi-physical field coupling to obtain a contact surface erosion simulation result. Setting material parameters in the modeling area to obtain a target three-dimensional electric arc model; resolving the target three-dimensional arc model through a solver according to the arc function and the contact movement function to obtain arc change parameters; establishing a three-dimensional contact model, performing parameter configuration and ablation model function setting on the three-dimensional contact model, and performing physical field configuration according to the arc change parameters to obtain a target three-dimensional contact model; and performing solver configuration on the target three-dimensional contact model to obtain contact surface topography parameters, and performing erosion analysis through the contact surface topography parameters. According to the invention, contact erosion caused by the electric arc can be accurately simulated.

The application establishes a short-circuit arc to a potential arc evolution process space-time evolution model, specifically including a short-circuit arc internal space electric field model and a potential arc evolution model with randomness. A large number of ions and electrons exist in the short-circuit arc channel, and the internal electric field of the short-circuit arc model cannot be directly calculated. The application establishes a short-circuit arc internal space electric field model based on a particle swarm algorithm and a simulation charge method to further obtain the short-circuit arc internal space electric field strength. Based on the above short-circuit arc internal electric field model, the short-circuit arc internal space electric field is used as an independent variable of the potential arc development to establish a short-circuit arc to a potential arc evolution model with randomness, and the space form of the potential arc at the evolution time is obtained. The application combines the physical characteristics of the short-circuit arc to the potential arc evolution, realizes the short-circuit arc to the potential arc evolution model based on the existing optimization algorithm, and provides technical support for the potential arc suppression in engineering.

The invention discloses a cable state evaluation method and device and a nonvolatile storage medium. The method comprises the following steps: constructing a fault arc model and a line model corresponding to a target cable; generating a simulation waveform based on the fault arc model and the line model; target fault parameters are determined based on the actual measurement waveform and the simulation waveform of the fault point in the target cable, and the target fault parameters represent index data describing fault characteristics and states; determining waveform characteristics of the fault point according to the target fault parameter; and determining a state evaluation result of the target cable based on the waveform characteristics. The technical problem that cable assessment is not accurate enough due to the fact that early faults, especially transient fault features, of cable equipment are difficult to sensitively capture and accurately assess at present is solved.

The invention relates to a modeling method for a ground fault simulation model of a ship medium-voltage DC system, and the method comprises the steps: building a simulation model of the ship medium-voltage DC system through simulation software, simplifying a generator set, and focusing on the change characteristics of voltage and current on a line in the system; establishing an arc model suitable for the ship medium-voltage direct current system, and analyzing the operation state and voltage and current characteristics of the system when an arcing fault occurs in the system through the arc model; for three different grounding fault types, namely a metallic grounding short-circuit fault, an arcing grounding fault and a high-resistance grounding fault, simulation analysis is carried out respectively, and fault features are extracted. According to the invention, the current characteristics of the medium-voltage DC system when three grounding faults with different resistance values occur are simulated, and a new method is provided for subsequent research.

The invention discloses a broadband conducted electromagnetic interference modeling method for very fast transient overcurrent on a secondary side of an electronic transformer, and belongs to the technical field of electromagnetic compatibility test simulation, and the method comprises the following steps: constructing a multi-arcing model of a GIS isolation switch, which is used for simulating and generating very fast transient overcurrent VFTC; the multi-arcing model is constructed by introducing fracture dynamic capacitance, establishing a segmented arc resistance model and setting arcing and quenching criteria; according to the method, fracture dynamic capacitance is introduced at the fracture of the disconnecting switch, segmented arc resistance models of three stages of pre-breakdown, steady-state combustion and arc quenching are fused, and meanwhile, accurate arcing and arc quenching criteria based on dynamic breakdown voltage and current zero-cross detection are set; the constructed multi-arcing model can highly vividly reproduce the VFTC waveform generated during the operation of the GIS disconnecting switch.

The application relates to a method and device for establishing a single-phase grounding fault arc model. The method comprises: collecting arc data and load data in an arc stage; and establishing an arc model according to the arc data and the load data, which comprises: obtaining an arc starting resistance according to arc current, arc voltage, load current and load voltage in an arc starting stage; obtaining an arc burning resistance according to arc current, arc voltage, load current and load voltage in a steady-state arc burning stage; and obtaining an arc extinguishing resistance according to arc current, arc voltage, load current and load voltage in an arc extinguishing stage. The application establishes the arc model in three stages, i.e., the arc starting stage, the steady-state arc burning stage and the arc extinguishing stage, so that the arc model in each stage is more in line with the arc characteristics of the respective stage, thereby better simulating an actual single-phase grounding fault arc.