70 results about "Arc model" patented technology

The invention relates to an automatic switching system from a geographical wiring diagram of a distribution network to a single line diagram; the system comprises a vector drawing tool of a single line diagram of a distribution network, which faces to a graphic object; the system also comprises a point arc model data structure, a breadth-first ergodic topology algorithm, an electrical primitive layout based on labyrinth algorithm, and elimination of primitive or line overlapping and intersection. A distribution network model based on CIM is proposed on the basis of geographic information of the distribution network by combining the vector drawing tool of the single line diagram of the distribution network, and automatic switching from the geographical wiring diagram of the distribution network to the single line diagram is realized according to the geographical wiring diagram of a distribution network to a single line diagram among geographical wiring diagram equipment by the labyrinthalgorithm and the method of eliminating overlapping and intersection method, thereby greatly reducing the working load of maintenance personnel of the single line diagram, eliminating the hidden trouble of inconsistence of data and diagram and improving the working efficiency of distribution departments and reliability of a power system in the practical application.

The invention discloses a parameterized sizing method for a turbine blade mould cavity. The parameterized sizing method comprises the following steps of: measuring an existing turbine blade to obtain a measurement model; performing registering positioning and precise registering on a computer-aided design (CAD) model and the corresponding measurement model to obtain geometric characteristic parameters of two-dimensional sections of the measurement model and the CAD model on the same height and calculating deformation vectors of the two-dimensional sections; conversely adjusting the deformation vectors and representing a middle arc model of a blade shape by using a cubic polynomial curve; then restoring the mould cavity; and repeatedly establishing at least four blade shape sections of the mould cavity at any height and finally reconstructing an entity of the mould cavity. By the parameterized sizing method, the product yield of the turbine blades is increased greatly and the period and the frequency of mould trail are reduced; and the parameterized sizing method has the characteristics of short design period, high precision and high efficiency.

The invention relates to a high-pressure gas breaker breaking performance assessment method and system. The method comprises the following steps of: carrying out magnet dynamic simulation on an arcing process of a high-pressure gas breaker to obtain total arc voltage and arc current before the arc current crosses zero; extracting model parameters of a preset zero area arc model; taking the total arc voltage and the arc current as initial conditions to solve past-arc current under the action of transient recovery voltage on the basis of the zero area arc model; judging whether the high-pressure gas breaker causes thermal breakdown or not in the breaking process according to change trend of the past-arc current; obtaining pressure intensity distribution and temperature distribution in an arc extinction chamber under the action of the past-arc current through magnet dynamic simulation, comparing field intensity, caused by the action of the transient recovery voltage, at each point of the arc extinction chamber, corresponding temperature and critical breakdown field intensity, and assessing the probability of electric breakdown in the arc extinction chamber. By adoption of the method and system provided by the invention, the comprehensive assessment for the past-arc thermal breakdown and electric breakdown characteristics of the high-pressure gas breaker is realized.

The invention provides a series fault arc detection device based on a convolutional neural network. The series fault arc detection device comprises a line current signal acquisition unit, a data processing unit, a fault arc model construction unit and a result output unit. The line current signal acquisition unit acquires and converts arc current data; the data processing unit arranges the arc current data into a current sample data set; and after an arc current database is established, a sample training set and a sample test set are formed. The fault arc detection model construction unit carries out normalization processing on the samples and constructs a series fault arc detection model based on a convolutional neural network for training and testing to obtain a trained series fault arcdetection model. The result output unit acquires arc current data to be detected and imports the arc current data to be detected into the trained series fault arc detection model to determine whetherthe arc current data to be detected are series fault arcs. The series fault arc detection device and method have the characteristics of strong generalization ability, high detection accuracy, low misjudgment rate and the like.

The invention discloses a vehicle-network model construction method for vehicle automatic passing neutral section of multiple unit, including the following steps: step 1, dividing a passing neutral section transient process of a long marshal multiple unit; step 2, obtaining a vehicle-network coupling distribution according to the transient process divided the step 1; step 3, constructing a vehicle-network system topological structure of different parts according to the vehicle-network coupling distribution result obtained in step 2; step 4, fitting an arc phenomenon during the occurrence of each transient process by the arc model according to the topological structure obtained in step 3. According to the vehicle-network model construction method for vehicle automatic passing neutral section of multiple unit, the capacitive coupling between the contact line, the neutral line and the vehicle body is considered, the vehicle-network coupling between the contact line and the neutral line cross section in the neutral section is also considered in detail, and an accurate overvoltage can be obtained.

The invention relates to a two-dimensional blade modeling method for directly controlling channel, and belongs to the technical field of aviation impeller machine design. A two-dimensional blade modeling method for directly controlling channel is provided for two-dimensional spanwise section modeling of blades of an axial-flow aero-engine fan and a compressor part, the method comprises steps of constructing a suction surface and an edge area molded line by utilizing a conventional multi-arc model, and calculating and adjusting a channel width distribution rule from the channel flow characteristic; by taking the suction surface as a reference, superposing the channel thickness to construct a part of pressure surface; and then complementing the rest of the pressure surfaces by using a cubiccurve to complete the two-dimensional blade profile construction. According to the method, the problem of irregular distribution of a plurality of sections of channel areas in a blade modeling methodof a median camber line + thickness is solved; the flexibility of channel area control is improved; the design efficiency of two-dimensional blade profiles in the compressor and the fan is improved; the channel diffusion capability can be directly evaluated, and the circulation performance of the designed blade profile is pre-judged.

The invention provides an arc modeling method for the high-resistance ground fault of a power transmission line. According to the method, a saturation current definite value IS and a reference voltage definite value UT are set according to the voltage level of a line, and the current iF of an arc branch is acquired. The arc voltage ua is calculated according to the formula ua=sgn(iF)*UT |n(|iF|/IS+1). After that, the fault point voltage is together established by the arc voltage in serial connection with a fixed grounding resistor RF. The above method is provided based on the Thompson principle for describing the air discharge essence, and the arc current is expressed based on the directional motion of a large number of electrons. Meanwhile, the function relationship between the arc voltage and the current is established based on the coupling relationship between the electric field and the electron avalanche motion in the arc space. In this way, a high-resistance ground fault arc model is established. According to the technical scheme of the invention, the physical nature of the air discharge of the arc fault is fully exploited. Therefore, the defect that a conventional arc differential equation is complex in computation and hard to directly apply can be overcome. The method is simple in computation and high in modeling accuracy, thereby having an important practical value in the field of subsequent high-resistance ground fault protection, control and ranging techniques.

The invention discloses a method and device for detecting overvoltage of a circuit breaker under multiple lightning strokes, and the method comprises the steps of collecting the data of equipment in astation, building a lightning invasion wave simulation model of a line-transformer substation in an electromagnetic transient program according to the data of the equipment in the station, the circuit breaker being simulated through a Cassie arc model; and acquiring lightning overvoltage of the circuit breaker in real time by adopting a multiple lightning counterattack tower and a shielding failure wire in the simulation model. According to the invention, the problems that the overvoltage of the circuit breaker under multiple lightning strokes is difficult to simulate and the simulation result is inaccurate are solved.

The invention discloses a method for recognizing sizes of pantograph-catenary current collection arcing. The method comprises the following steps of: obtaining data set pictures and generating the data set pictures into a training set and a test set; establishing an arcing model, wherein the arcing model is a convolutional neural network model; training the arcing model by utilizing pictures of the training set, and adjusting and optimizing model parameters to obtain an optimized arcing model; and recognizing pictures of the test set by utilizing the optimized arcing model. According to the method, pantograph-catenary current collection arcing pictures are classified and the sizes of arcing are judged by adoption of the arcing model, so that when being compared with existing methods, the method is capable of greatly decreasing the parameter amount and calculated amount during the training, and saving the consumption of resources and time; and meanwhile, through network deepening, relatively high correctness is ensured, so that the sizes of pantograph-catenary current collection arcing are automatically recognized and the method is adapted to practical industrial application.

The invention relates to an early-warning method for an arcing fault of an AC circuit breaker. The early-warning method is used for early warning by acquiring a dynamic arcing model of the AC circuit breaker. The method comprises the following steps of 1) dividing arcing process of the AC circuit breaker into three steps in continuous time, wherein the three steps comprise a prebreakdown step, an arcing step and an arc failure step; 2) respectively acquiring step arcing models corresponding to the prebreakdown step, the arcing step and the arc failure step; 3) combining all step arcing models according to continuous time to finally acquire the dynamic arcing model of the AC circuit breaker; and 4) performing arcing fault early-warning of the circuit breaker according to the dynamic arcing model of the AC circuit breaker. Compared with the prior art, the method has the advantages of technological support and the like, and is more coincide with and conforms to an actual condition.

The invention relates to a high-frequency arc modeling method for a circuit breaker, and belongs to the technical field of power system protection and fault monitoring. According to the method, a three-section type arc whole process model is built according to changes of arc currents at different moments. A pre-arcing stage is represented by using a conventional time-varying resistor model; a steady-state arcing stage is represented by using a settable fixed resistance value; and an arcing stage is represented by using a Mayr arc model. The arc modeling method provided by the invention can provide a theoretical basis for arcing fault early warning and identification of the circuit breaker.

The invention discloses a single-phase arc high-resistance ground fault location method for wind farm current collection lines. The method includes measuring the fault phase voltage, phase current, and zero sequence current after 20ms failure of the protection installation place of a current collection line outlet of a wind farm as input; solving the fault current of each fan branch based on the principle of equipartition; fitting with the fault branch current by utilizing the zero sequence current at the current collection line outlet of the wind farm; solving the voltage drop of the fault branches by combining a logarithmic arc model; writing a time domain voltage loop equation between the current collection line outlet and a grounding point based on the topological structure of the current collection line; assuming a fault section initial value, and adopting a damped least square method to perform nonlinear fitting solution on a range finding equation; piecewise calculating fault distances; and finishing searching when the calculated fault distance value is located at the assumed fault section so that the calculated fault distance value at this moment is a range finding results. The method can be directly applied to standard configuration fault recorders of transformer stations without installing new measurement equipment, so that the method is low in cost and fast in algorithm convergence speed.

A data processing method for error correction of logarithmic arc model simulation data is disclosed. A logarithmic arc model simulation data sequence P (V, I) with one cycle is obtained. The arc voltage Vmax and- Vmax is the data demarcation point, and P (V, I) is divided into two 1/2 periodic data sequences. By choosing appropriate correction parameters, the correction equation is established asfollows: L: Varc=f (Iarc) to V'arc=f (I'arc), and a new data sequence P '(V', I ') is obtained. The corrected data P '(V', I ') have the same characteristics as the real recorded data V-I curve is more close to the external characteristics, which provides data support for the subsequent research of arc grounding fault; the invention aims at solving the problem that the simulation waveform of the logarithmic arc model uarc=sgn (iarc) UTln (| iarc | /IS+1) can not characterize the measured arc V. The simulation waveform of the logarithmic arc model uarc=sgn (iarc) UTln (| iarc | /IS+1) can not represent the measured arc V. I phase angle difference problem, the corrected data has more close to the actual arc external characteristics, improve the accuracy of the logarithmic arc model simulation data.

The invention discloses a high-speed rail train-network model construction method considering multi-train pantograph-catenary vibration off-line arcing. The method comprises the following steps that 1, acquiring train-network coupling distribution of multiple motor train units when the multiple motor train units run on the same or adjacent power supply arms; 2, constructing a vehicle-network topology according to the vehicle-network coupling distribution; 3, introducing a combined model of the Habedank equivalent arc model and a switch into the arcing bow head position of the motor train unitin the train-network topology to obtain a train-network model considering the bow-network vibration offline arcing situation of overlapping of multiple train occurrence time periods; 4, calculating parameters of the vehicle-network model, and simulating the vehicle-network model to carry out electromagnetic transient analysis of simultaneous pantograph arcing of multiple vehicles. According to themodel constructed by the invention, the actual capacitive coupling between the contact network and the vehicle body and between the contact network and the vehicle roof high-voltage cable is increased, and the situation that multiple vehicles simultaneously generate bow net vibration off-line arcing is also considered; and an accurate data source and a theoretical research basis are provided forsolving the electromagnetic transient overvoltage problem of the high-speed rail at present.

The invention discloses a power distribution network primary and secondary fusion intelligent switch high-frequency conduction interference test simulation method. The method comprises the following step of S1, modeling and simulating through simulation software, establishing a 10kV power distribution system simulation model, considering several operating conditions which can generate high-frequency interference signals, simulating an over-voltage and a high-frequency interference generated by faults or operations, and establishing a switching action arcing model. The invention relates to theelectromagnetic compatibility test simulation technology field. By using the power distribution network primary and secondary fusion intelligent switch high-frequency conduction interference test simulation method, a system simulation model and a tested equipment model are combined to simulate the generation, propagation and effect processes of a high frequency interference signal. And simultaneously, a stray parameter loop is added in a loop so that a condition that a complicated electromagnetic environment and the interference of the high-frequency signal often make a switch generate a delayaction or even maloperation and refuse to operate when a control loop is installed near equipment can be avoided, thereby, the stable operation of the power distribution network is ensured.

The present application discloses a cassie-Mayr arc model simulation method, including: through the finite element simulation software to establish the MHD arc simulation, to determine the arc dissipation power and arc voltage, arc current in a fixed medium; Assuming that the cassier arc model and the mayr arc model are two non-linear arc resistances, the relationship between the arc resistance and the proportional coefficient is established; Build cassie with pscad software- Mayr arc model, and establish the relation function of arc resistance and arc voltage and proportion coefficient; The simulation parameters are selected, and the arc is simulated according to the relation function of the arc resistance and the arc voltage and the proportion coefficient. By combining the cassie arc model and the mayr arc model according to a certain proportion, the application can accurately simulate the characteristics of the arc in the vicinity of the large current region and the current zero region, establish an arc model with wide application range, simple model and high simulation precision, and improve the simulation efficiency and precision.

The invention provides a continuous casting machine roller array curve design device and method. The device comprises a display input unit, a calculation unit, an interpolation unit, a modeling unit, an obtaining unit and a roller arranging unit. The display input unit is used for inputting bending straightening conditions and design parameters and displaying roller array curves and key point and interpolation point coordinate values. The calculation unit calculates outer arc and inner arc key point and interpolation point coordinates in a mixed bending straightening mode. The interpolation unit performs interpolation among the key points. The modeling unit builds a continuous casting machine outer arc and inner arc models according to the key point and interpolation point coordinates calculated by the calculation unit. The obtaining unit obtains mixed coefficients according to the models and the roller mounting accuracy to obtain outer arc and inner arc key point and interpolation point coordinate values. The roller arranging unit arranges rollers on the continuous casting machine outer and inner arcs according to space between rollers to obtain coordinates of the centers of all the rollers to obtain the continuous casting machine roller array curve. By means of the device and the method, stress of the rollers is reduced effectively, and the mounting accuracy requirement is met.

The invention discloses a power distribution network overvoltage fault type intelligent identification method and a fault identification unit, and belongs to the technical field of overvoltage fault identification. A power distribution network overvoltage fault type intelligent identification method comprises the following steps: establishing a single-phase arc light grounding fault simulation model of a neutral ungrounded system based on a Cassie arc model, and simulating to obtain a three-phase voltage and current oscillogram before and after single-phase grounding before and after a fault; by collecting three-phase voltage, open triangular voltage and primary side neutral point current of a voltage transformer, 11 fault types of metal grounding, arc grounding, medium resistance grounding, high resistance grounding, under/overvoltage, PT disconnection and resonance of different frequencies are identified, the fault type of the system is judged, early warning and suppression are carried out on the degree of harm, and the system reliability is improved. And a movable fault type intelligent fault identification unit is established for the erected cable, so that the device is stable in movement and convenient to disassemble, and can move on the high-voltage cable to carry out multi-point detection so as to realize accurate identification of a fault position.

The invention discloses an analysis method for a distribution network successive fault coupling propagation mechanism, and the method comprises the steps of 1, selecting a high-voltage power transmission line with a multi-feeder successive fault, and collecting the related parameters of the high-voltage power transmission line; 2, establishing a high-voltage side simulation model, and establishinga high-voltage side simulation model feeder line according to related parameters of the high-voltage power transmission line; 3, connecting an arc model to the feeder line, recording a simulation result of the arc model, and comparing the simulation result with an actual recording waveform and a sequence record. A simulation model is built through ATP-EMTP simulation software, and by selecting and improving an arc model, a simulation result is conveniently compared with an actual recording waveform and an event sequence record, and feedback improvement is carried out on the established simulation model and parameter setting according to the comparison, so that the development process of a system instable ground fault is analyzed, and a general rule of a fault coupling propagation mechanism can be given.

The invention discloses a simulation method and device for a single-pole grounding fault arc model. The method is applied to a true bipolar flexible direct current system, in the method, a primary arc theory and a secondary arc theory are combined, an arc model is constructed, the dynamic change characteristics of a fault arc are simulated in PSCAD through fault branch arc current and arc voltage, and the dynamic change characteristics comprise the nonlinear characteristic and the self-extinguishing characteristic. According to the application, the arc current and the arc voltage are taken as the input quantity of the arc model, the arc resistance is calculated and output through the arc model, and is fed back to the fault branch as the resistance value of the nonlinear resistor, so that the arc resistance values of different stages are simulated, and the simulation of the arc self-extinguishing characteristic is realized; the non-linear characteristic of the arc is embodied by the arc current and the arc voltage. The extinguishing moment of the arc is obtained according to an actual application scene in the simulation process, and the unipolar grounding fault arc characteristics of the true bipolar flexible direct current system can be simulated more truly.