259 results about "Analytic expression" patented technology

The present invention relates to the technical field of power transmission conductor galloping, and in particular to a method for solving a conductor galloping trajectory equation of a high-voltage transmission line. The method comprises the following steps: establishing a coordinate system; analyzing a nonlinear motion of any point on a conductor; solving a conductor galloping trajectory equation; solving a torsion angle and an acceleration under an arc length constraint; and carrying out convex optimization on an analytic expression of the torsion angle. According to the present invention, an inter-station RTK differential mode is used, and Beidou observation data analyzed by a monitoring station and Beidou observation data analyzed by a reference station are combined, thereby improving the accuracy of a monitoring result; a finite element analysis method is used to carry out discretization processing on the problem of conductor motion integral, so that conductor displacement can be effectively restored to obtain a good curve fitting effect; and a calculation method for the torsion angle under the limitation of the arc length of the conductor is provided, overcoming the error of calculating a trajectory integral by using the acceleration, and an optimized calculation method is provided.

The invention discloses a single-epoch GNSS-oriented PAR ambiguity precision factor determination method, and relates to the technical field of satellite navigation and positioning. Comprising the following steps: dividing pseudo-range and carrier wave observed quantities in a GNSS double-difference mathematical model into two groups, and constructing a function relationship between a floating point solution # imgabs1 # and a floating point solution # imgabs2 # variance-covariance matrix of an ambiguity vector # imgabs0 #; constructing a single-frequency single-epoch single-system P-ADOP expression and establishing a shrinkage factor k de-inversion transformation analytic expression, and simultaneously obtaining a single-frequency single-epoch single-system GNSS non-inverse transformation P-ADOP approximation formula; and performing analogy derivation on the single-frequency single-epoch single-system non-inverse transformation P-ADOP approximate formula to obtain a single-frequency multi-system or multi-frequency single-epoch GNSS non-inverse transformation P-ADOP general approximate formula. The method has important theoretical value and practical guiding significance for GNSS optimal ambiguity subset rapid selection and positioning and partial ambiguity fixing success rate influence mechanism analysis.

The invention discloses an integral equation general solution method for horizontal bearing characteristics of a pile body composite foundation, which comprises the following steps of: S1, establishing a pile body composite foundation schematic diagram consisting of N (N = n1 * n2) foundation piles and a coordinate system {0, x, y, z} thereof, and dividing the pile body composite foundation schematic diagram into m subunits by taking a pile diameter d as a side length; determining the load resultant force V (y, 0) of the top of each subunit according to the horizontal load H0 of the upper structure borne by the foundation; s2, the pile-soil system is decomposed into semi-infinite space expansion soil and virtual pile units, and stress analysis schematic diagrams of the corresponding units are obtained; obtaining analytic expressions of pile body deflection # imgabs0 # and bending moment # imgabs1 # according to static equilibrium conditions and geometric conditions of the ith (i = 1,..., N) virtual pile unit; and S5, the lateral displacement # imgabs2 # of the extended soil unit at the corresponding position of the ith virtual pile is obtained based on the Mindlin solution, according to the lateral displacement coordination condition of the semi-infinite space extended soil and the virtual pile unit at the corresponding position, an integral control equation of the horizontal bearing characteristic of the pile body composite foundation is established, and then the pile body deflection and the internal force of the pile body composite foundation are obtained.

The invention relates to the field of heat supply network analogue simulation, and particularly discloses a regional heat supply network dynamic simulation method and system, a terminal and a medium, the method comprises the following steps: constructing a hydraulic model semi-analytical expression and a thermal model semi-analytical expression of a pipeline in a regional heat supply network, and according to the pipeline momentum conservation and the node mass conservation, calculating the thermal model semi-analytical expression of the pipeline in the regional heat supply network; constructing semi-analytic coefficient recursive relation linear equations, and respectively calculating semi-analytic coefficients of a hydraulic model semi-analytic expression and a thermal model semi-analytic expression through the two semi-analytic coefficient recursive relation linear equations according to initial conditions and boundary conditions of the pipe section; the calculated semi-analytic coefficient meets the condition that the truncation error is not greater than a truncation error threshold value; and substituting the semi-analytic coefficient into the semi-analytic expression to obtain a semi-analytic calculation result of each pipe section of each pipeline under all time steps. According to the method, non-iterative calculation of the PDAEs is realized, the calculation complexity is reduced, the simulation efficiency is improved, and the solution continuity can be ensured.

A design method of a trust region satellite-borne dual-base interference SAR system is provided, relating to the field of radar measurement. Firstly, error sources of the interference SAR system are classified and analyzed, phase errors caused by image decoherence are calculated according to wave positions, and an analytical expression of baseline-related errors is reserved; a maximum phase error caused by imaging processing and an electronic device are estimated; and a baseline error is estimated. Then, the phase errors and the baseline errors are converted into elevation errors through an elevation fuzzy number, thereby obtaining an analytical expression of the elevation errors and the baseline parameters (length and dip angle). With a relative height measurement accuracy index of the system as an optimization object, a feasible solution interval between the baseline length and the baseline dip angle of the system is solved through a trust region algorithm. A minimum value of the baseline length is corrected according to a flying-around safety distance of a dual-satellite formation. According to the method of the present disclosure, the design of the satellite-borne dual-base interference SAR system can be guided, so that the satellite-borne dual-base interference SAR system is ensured to carry out terrain elevation surveying and mapping tasks with high accuracy and high reliability.

The invention provides a logarithmic terminal sliding mode control method for a nonlinear system, and belongs to the technical field of sliding mode control. According to the invention, a first-order logarithmic terminal sliding mode control strategy and a super-torsion logarithmic terminal sliding mode control strategy are obtained based on a designed logarithmic terminal sliding mode surface, a logarithmic terminal sliding mode cooperative control architecture oriented to a nonlinear system is obtained, multi-objective optimization of buffeting suppression, global rapid convergence and sliding time explicit is realized, and the method is suitable for large-scale popularization and application. The global convergence speed of the system state on the sliding mode surface can be improved while sliding mode control buffeting is weakened, the sliding time of the system state on the sliding mode surface is explicitly given, the strict mathematical correspondence between the controller gain coefficient and the system dynamic performance is determined through the explicit analytical expression of the sliding time parameter, and the system dynamic performance is improved. A quantitative theoretical basis is provided for parameter setting of an industrial field, and the system robustness under a complex working condition is remarkably enhanced.

The invention provides a DCIM-based method for rapidly calculating a green function of a uniaxial anisotropic layered medium and an electromagnetic simulation system. The method comprises the following steps: modeling a uniaxial anisotropic layered medium to be simulated; determining a uniaxial anisotropic dielectric material of each layer, and assigning transverse parameters and longitudinal parameters; determining longitudinal coordinates of field point and source point distribution required to be solved, fitting a uniaxial anisotropic medium Green function spectral domain expression under the field source distribution by using a DCIM method, and solving an analytical expression in a spatial domain by using Somerfeld identical equation properties; solving the size of the electromagnetic field on the plane according to the fitted analytical expression; compared with a direct numerical integration method or a finite element method numerical solution using the Green function, the method has the advantages that the airspace analytical expression corresponding to the field source distributed on the plane is directly fitted, so that the solution of the airspace Green function is greatly accelerated, and the calculation efficiency and the calculation precision are both good in an actual example.

The invention relates to the technical field of power supply and demand interaction, in order to realize efficient and economical power dispatching, a micro-grid master-slave game optimization dispatching method considering user flexible load demand response comprises the following steps: step 1, establishing a micro-grid day-ahead supply and demand interaction scene in which a single micro-grid operator participates with a plurality of users; 2, constructing an MGO leader optimization scheduling model considering the uncertainty of the user response power; step 3, constructing a user follower demand response model taking maximized participation DR income as a target function; 4, converting the chance constraint into a deterministic linear constraint and a second-order cone constraint which can be solved; and 5, solving the MGO and the master-slave game model of each user by adopting an analytic expression solving method. The method is mainly applied to power dispatching occasions.

The embodiment of the invention provides an intelligent reflecting surface coverage enhancement method and device for electric power inspection, and the method comprises the steps: building an intelligent reflecting surface and inspection equipment unified scheduling model, and building a unified scheduling model for a multi-intelligent reflecting surface networking network; deducing a signal interference distribution analytic expression, solving a space measure function of a point process and determining heterogeneous station density based on an interference level; constructing a multi-intelligent reflector networking correlation model, and analyzing a link coupling factor; based on modeling of a link coupling factor, the link performance under the collaborative networking is studied; a cross-domain reconfigurable capability boundary is explored, and a spatial statistical average analysis method for coverage, capacity and mobility performance is innovated; an adjustable intelligent reflecting surface distribution dependence model is provided, and a semi-closed theoretical analysis expression of the user coverage rate is given based on a stochastic geometric tool.

The invention discloses a human body posture intelligent identification method based on a multi-modal micro-motion feature and a Transform network, and the method comprises the steps: deducing micro-Doppler signal mathematical analysis expressions corresponding to different parts of a human body from human body target radar echo modeling; the method comprises the following steps: performing data preprocessing on target echo data acquired by a millimeter wave radar by adopting two-dimensional fast Fourier transform to obtain a one-dimensional spectrum sequence and a two-dimensional Doppler image corresponding to different postures, and respectively sending the one-dimensional spectrum sequence and the two-dimensional Doppler image into a one-dimensional Transform network and a two-dimensional Transform network for feature extraction; and carrying out feature splicing by adopting a multi-modal feature fusion model and outputting a classification result. According to the method, the problems of low recognition rate, poor robustness and the like in the existing human body posture intelligent recognition means can be solved.

The invention discloses a low torsional rigidity design and calculation method for a permanent magnet coupling. According to the method, through the low-torsional-rigidity structural design, transmission of vibration from the driving end to the load end can be effectively reduced, the service life of shafting parts is prolonged, the transmission reliability is improved, and the high practical application value is achieved; besides, according to the magnetic circuit forming characteristics of the drum-type permanent magnet coupling, an equivalent magnetic circuit of the drum-type permanent magnet coupling is constructed based on an equivalent magnetic circuit method, the torque and rigidity analytic expression of the drum-type permanent magnet coupling is deduced by solving the magnetic circuit, and finite element calculation which is long in time consumption and complex in calculation does not need to be carried out. The method can provide important technical support for the initial stage of design, torsional rigidity prediction, vibration reduction and isolation effect evaluation and the like of the drum-type permanent magnet coupler, and has the advantages of simplicity in operation, high adaptability, short calculation time and the like in practical engineering application. The method is a calculation method with engineering practical application value.

Provided are analytical expressions for multi-sample preference sampling distributions. A distillation training approach can be framed as a distribution matching problem with respect to one of these analytical expressions. The distribution matching problem can be solved using various algorithms. For example, a student model can be finetuned via policy distillation techniques. The resulting student model is therefore able to provide the benefits of the multi-sample preference sampling process, including its robustness and ability to align with human preferences, while significantly reducing the computational overhead at inference time.

The invention belongs to the technical field of aircraft structure design, and particularly relates to an aircraft arbitrary space four-bar mechanism parameter optimization method, which comprises the following steps: firstly, determining input conditions or preposed requirements of a four-bar mechanism, secondly, establishing a mathematical model of a four-bar mechanism optimization problem, and then, carrying out derivation and analysis to obtain a four-bar mechanism parameter optimization result. The method comprises the following steps: establishing an analytic expression of parameter variables of the four-bar mechanism and compiling a corresponding calculation program, then carrying out iterative optimization on the parameters of the four-bar mechanism by utilizing an optimization algorithm, and finally outputting an optimization result to obtain an optimal design parameter.

Disclosed are techniques for an AI system with a large language mode (LLM) with improved accuracy and reliability in solving mathematical problems. An initial query is transformed into a template query by replacing the original input values with variables. Multiple prompts are sent to the LLM, each being different from one another, and contextually related to the template query. Multiple results are responsively received from the LLM, each result including an analytical expression to solve the mathematical problem. Each of the expressions is evaluated using a numerical evaluation tool with variables of the expression being assigned a common set of randomly sampled values. A consensus is achieved when the evaluated expressions satisfy a consensus condition, such as when all outputs match consistently over N experiments or trials. After the consensus condition is reached, the original inputs are evaluated with one or more of the expressions, and the solution is output.

The invention relates to the technical field of traveling wave analysis, in particular to an alternating-current power system fault traveling wave analysis method and system, and the method comprises the steps: constructing a fault component network at an alternating-current line fault point according to a fault current component and a fault voltage component at the fault point of an alternating-current power system; according to the fault component network, analyzing current and voltage changes at a fault point by using a Kirchhoff's law, and determining a boundary condition of the fault point; based on the boundary condition of the fault point, solving a mode fault component analytical expression at the fault point of the alternating current line by using phase-mode transformation and an Ohm law; and according to the physical propagation characteristics of the alternating current line and the mode fault component analytical expression, obtaining a fault traveling wave wavefront analytical component at the traveling wave protection installation position by using a Laplace transformation algorithm. According to the method, the wavefront information of the fault traveling wave at the fault point is accurately analyzed by combining the fault component network and the circuit theory, a more reliable basis is provided for fault detection, and the safety and stability of a power system are improved.

The invention belongs to the technical field of resource planning, and particularly relates to a power distribution network distributed resource robust planning method and device based on cluster division, and the method comprises the steps: building a source-storage robust locating and sizing model as an upper model based on cluster division, and setting a target function and constraint conditions thereof; based on cluster planning, constructing an intra-cluster reliability index calculation model as a lower-layer model, and setting a target function; combining the upper-layer model and the lower-layer model to obtain a double-layer joint planning model; aiming at an island operation scene under a cluster division condition, designing a reliability merging optimization method integrated with island operation characteristics, and optimizing the double-layer joint planning model to obtain an analytical expression of a reliability index; and obtaining a joint planning scheme of the distributed resources of the power distribution network by solving the optimized double-layer joint planning model. According to the method, the source load uncertainty and the reliability index are effectively considered, and the economical efficiency, the flexibility and the reliability of power distribution network planning are remarkably improved.

The invention discloses a geometric analytic expression three-dimensional reconstruction method, and relates to the technical field of computer vision and three-dimensional environment perception. According to the method, for an application scene with a target area located in a known space attitude plane, an accurate geometric mapping relation among a navigation coordinate system, a camera coordinate system and an imaging plane is constructed by fusing a visible light image, a single-point distance measurement value and attitude information output by an attitude sensor (such as an IMU); and pixel-level depth estimation is realized by adopting an analytic expression calculation strategy, so that high-precision and low-complexity three-dimensional reconstruction of a coplanar region is completed.

The embodiment of the invention discloses an energy storage converter parameter adaptive adjustment method, and the method comprises the steps: constructing an equivalent circuit of an energy storage converter, and determining an electrical parameter analytical expression of the energy storage converter; processing the electrical parameter analytical expression of the energy storage converter according to a Lyapunov stability criterion, and determining a theoretical power maximum value Pmax; and collecting the output active power P of the energy storage converter in real time, and adjusting the parameters of the energy storage converter according to the comparison relationship between the output active power P and the theoretical power maximum value Pmax. Through accurate modeling, real-time monitoring and self-adaptive adjustment, optimal adjustment of parameters of the energy storage converter is realized, the working efficiency and stability of the energy storage converter are improved, the maintenance cost is reduced, and a powerful guarantee is provided for reliable operation of an energy storage system.

The application discloses a kind of analytic expression probabilistic power flow calculation method, device and storage medium.The application is determined after the mapping relationship between the injection power of node and the operating state of power system by linear power flow model, using first-order polynomial fitting correction method to revise the operating state of power system, make the operating state of the power system after revision be closer to real operating state, according to the mapping relationship between the injection power of node and the operating state of power system after revision, update linear power flow model, carry out analytic expression probabilistic power flow calculation using updated linear power flow model, to effectively improve the accuracy of probabilistic power flow calculation.

The invention relates to the technical field of broadband radar signals, and provides a radar target robust intelligent detection and interference adaptive suppression method and system, and the method comprises the steps: carrying out the decorrelation transformation of received data and a parameter matrix through employing the skew symmetry characteristic of a clutter covariance matrix, and completing the preprocessing of initial data; carrying out correlation calculation estimation under the condition of no target hypothesis and under the condition of target hypothesis, and constructing distance extension target Gradient detection statistics under the condition of a known clutter skew symmetry covariance matrix; constructing a detection statistic lambda of the radar target robust intelligent detection and interference adaptive suppression method; and determining a detection threshold T through theoretical calculation or Monte Carlo simulation according to a preset false alarm probability, comparing the detection statistic lambda with the detection threshold T, and judging whether a distance expansion target exists in the current distance unit to be detected or not according to a comparison result. According to the method, an analytical expression design is adopted, a complex iterative calculation process is avoided, and the operation efficiency is improved.

The invention discloses a PID parameter setting method for suppressing conflict between primary frequency modulation and secondary frequency modulation of a hydroelectric generating set, and belongs to the technical field of hydroelectric generating set adjustment. Comprising the following steps: S1, calculating an initial value of a PID (Proportion Integration Differentiation) parameter according to a water diversion system water flow inertia time constant and a hydroelectric generating set mechanical inertia time constant; s2, taking the PID parameter initial value of the speed regulator as a PID parameter value, solving the root of the characteristic equation in the S1, and calculating a unit power dynamic analytical expression during frequency unit step disturbance according to a Fisher method of a quartic equation; s3, calculating an analytic expression of the hydroelectric generating set power square error integral quantity based on the unit power dynamic analytic expression; and S4, calculating a speed regulator PID parameter formula for suppressing the conflict between the primary frequency modulation and the secondary frequency modulation of the hydroelectric generating set according to the analytic expression of the unit power square error integral quantity and the initial value of the speed regulator PID parameter. The problem that the dynamic process of primary frequency modulation and the dynamic process of secondary frequency modulation conflict is solved, and the adjusting capacity of the hydroelectric generating set can be brought into full play.

The invention discloses a doubly-fed wind turbine generator fault current analysis and controller parameter identification method, a storage medium and equipment, and belongs to the technical field of electric power. The method aims at solving the problems that an existing identification method for the double-fed fan in the fault state is low in identification precision, depends on optimization algorithm performance and is not suitable for practical engineering due to the fact that an identification scene is too ideal. According to the method, firstly, an accurate and detailed doubly-fed fan topology, an RSC controller and an LVRT control strategy are established, and then a detailed doubly-fed fan fault current analytic expression is obtained through derivation of a mathematical model; a reactive support coefficient, a reactive voltage threshold and a maximum current are determined through a voltage drop fault test, then a rotor reactive current reference value is obtained according to a voltage drop value corresponding to a new fault, the reactive support coefficient and the reactive voltage threshold, and a power current reference value is obtained by combining the maximum current. And controller parameters in the RSC controller are identified based on the fault current analytical expression.

The invention discloses an analytical calculation method, system and equipment for transient voltage and current of a power grid fault. The method comprises the following steps: constructing a fault resistance network matrix; calculating a voltage and current initial traveling wave at the fault point by adopting phase-mode transformation at least based on the fault resistance network matrix; constructing a fault component additional network; respectively calculating a first traveling wave refraction and reflection coefficient at a fault point and a second traveling wave refraction and reflection coefficient at a non-fault point in the fault component additional network; respectively acquiring all first traveling wave propagation paths and all second traveling wave propagation paths, and calculating the total propagation time and the total traveling wave refraction and reflection coefficient on each traveling wave propagation path at least based on the first traveling wave refraction and reflection coefficient and the second traveling wave refraction and reflection coefficient; and at least based on the total propagation time and the total traveling wave refraction and reflection coefficient, performing summation and superposition to obtain a fault transient voltage and current analytic expression. According to the method, a reliable theoretical basis can be provided for development of a relay protection and fault positioning technology based on high-frequency transient information.

The invention discloses a method for calculating the diffusion coefficient of an electrode material, which comprises the following steps: establishing a Fick diffusion law-based constant current gap titration (GITT) theoretical model, and describing the concentration distribution of ions in the electrode material; solving a partial differential equation in the GITT theoretical model through Laplace transformation to obtain an analytical expression of ion concentration; obtaining a diffusion coefficient calculation formula suitable for a full time range; verifying the accuracy of the diffusion coefficient calculation formula through numerical simulation; and a concentration-based diffusion coefficient expression is converted into a voltage-based diffusion coefficient expression, so that processing and analysis of experimental data are facilitated. The method for calculating the diffusion coefficient of the electrode material, provided by the invention, is based on a constant current gap titration technology, is suitable for full-range data, extracts experimental data, calculates a voltage difference, selects an optimal formula and generates a visual image through an automatic program, and remarkably improves the calculation precision of the diffusion coefficient and the processing efficiency of the experimental data.

The invention discloses a linear variation stiffness matrix method for suspension bridge space cable forming form finding, relates to the technical field of bridge numerical simulation, and solves the defects of a stiffness matrix in the process of solving the suspension bridge forming form finding through a segmented catenary method. The method comprises the steps that a suspension bridge is simplified into a space cable system composed of a main span, a side span and an anchor span, and the main span, the side span and the anchor span are sequentially subjected to a bridge forming and shape finding process; the linear change stiffness matrix solved in the bridge forming and shape finding process of the main span is used for representing the linear relation between the displacement change of the control point and the initial force change of the main cable; according to the method, an analytical expression of a linear change stiffness matrix is deduced, and an efficient iterative algorithm is established. According to the algorithm, the initial force correction is directly calculated according to the displacement error of the control point in each iteration.

The invention relates to an off-axis three-reflector system design method and system based on a vector aberration theory. The method comprises the following steps: determining the focal length of an off-axis three-reflector system; determining the distance between the mirrors and the distance between the three reflectors and the image surface; according to the design requirements of the coaxial three-reflector system, calculating the curvature radiuses and quadric surface coefficients of the three reflectors; calculating the pupil radius of the pupil off-axis front three-reflector system according to the relationship between the pupil radius before and after the pupil off-axis and the pupil eccentric vector, and determining a wave aberration expression of the pupil off-axis rear three-reflector system; based on a paraxial ray tracing method and a vector aberration theory, establishing analytic expressions of a visual axis error, an increased coma error and an increased astigmatic aberration on a primary imaging surface about an inclination amount and an eccentricity amount; by taking optical axis error, coma error minimization and astigmatic aberration minimization as constraint conditions, optimally solving inclination amounts and eccentricity amounts of the three reflectors; structural parameters of the three-mirror system are optimized through optical simulation software. The efficient and reliable design method and system are achieved.

The invention belongs to the technical field of rub-impact force calculation, and discloses a blade-coating casing normal rub-impact force calculation method considering a heat-wear effect. Based on a one-dimensional unsteady state heat conduction theory, analytic expressions of temperature rise and linear thermal expansion of the blade and the casing are respectively established, and instantaneous temperature change in each contact process is considered. Secondly, physical modeling of various abrasion mechanisms (such as cutting type abrasion, adhesive abrasion and microcrack abrasion) is introduced, and the influence of coating gap changes on the contact force is effectively captured; in addition, the composite stiffness characteristics of the casing coating and the supporting structure are further integrated, so that the rub-impact force calculation can cover the response characteristics under different structural stiffness conditions. Through finite element comparison and experimental verification, the calculation method disclosed by the invention shows relatively high precision in the aspects of predicting thermal deformation, contact force and wear trend, and provides powerful support for subsequent rub-impact fault diagnosis and structural design.

The invention provides a new energy grid-connected short-circuit current and peak value calculation method considering a voltage drop transient state, and belongs to the field of new energy grid-connected system short-circuit current calculation. According to the method, a topological structure and electrical parameters of the doubly-fed wind power generation system are imported, an electromagnetic differential equation is established, a fault voltage initial value expression is deduced, a matrix equation is constructed to solve a node voltage initial value and a loop current derivative initial value, an equivalent attenuation time constant after a fault is calculated, and an approximate analytical expression of a node voltage drop process is established. And calculating a fault point short-circuit current peak value and a double-fed fan short-circuit current peak value. According to the new energy grid-connected short-circuit current and peak value calculation method considering the voltage drop transient state, full-time-domain iterative calculation is avoided, calculation precision and convergence are both considered, the method is suitable for a doubly-fed wind power generation system, and important reference can be provided for equipment type selection and protection setting calculation.

The invention discloses a full-power type wind turbine generator fault occurrence moment current analysis method and related equipment, and the method comprises the steps: obtaining control parameters and operation parameters of a full-power type wind turbine generator, and when low-voltage fault ride-through is detected, substituting the control parameters and the operation parameters into a fault ride-through controller model, fault current partition logic is combined to obtain fault current analytic expressions corresponding to different fault state intervals, and then the current instruction data are substituted into the fault current analytic expressions under the corresponding fault state intervals, so that current analysis is carried out through the fault current analytic expressions and a closed-loop transfer function, and fault current analysis is carried out through the fault current analytic expressions and the closed-loop transfer function. And obtaining the fault current at the fault occurrence moment of the full-power wind turbine generator. According to the scheme, the control strategy of the active and reactive current during low voltage ride through is analyzed, and the current analysis formula of the fault occurrence moment corresponding to each fault current partition is obtained by combining different fault current partitions, so that the fault current of the unit fault occurrence moment is obtained based on the current analysis formula.

A double-lane millimeter wave vehicle networking safety transmission method, system, device and medium based on STAR-RIS, the method comprising: constructing a STAR-RIS assisted double-lane millimeter wave vehicle networking communication scene; based on the propagation characteristics of millimeter wave signals, combining the channel fading characteristics under the conditions of line-of-sight and non-line-of-sight transmission and the transmission and reflection functions of STAR-RIS, calculating the channel gain of the cascaded channel of the STAR-RIS assisted link; based on the random geometry theory, respectively calculating the probability density functions of the associated distances of the direct link, the STAR-RIS reflection link and the STAR-RIS transmission link; constructing a dynamic link association strategy supporting ternary selection; establishing a signal-to-interference-and-noise ratio model under three association modes; combining the physical layer security performance index definition, calculating the closed-form analytical expressions of the connection interruption probability and the secrecy interruption probability, and verifying the security gain of STAR-RIS; the present application has the advantages of effectively overcoming the half-space coverage blind area of the traditional reflective RIS, and improving the link connection reliability and physical layer safety transmission performance under the double-lane complex shielding environment.