14results about How to "Promote engineering application" patented technology

This invention discloses a highly generalizable method for diagnosing open-circuit faults in multi-transistor converters of motor drive systems. This method addresses open-circuit faults in power devices caused by overcurrent surges, poor heat dissipation, and other factors, preventing damage to the motor and power grid equipment caused by output current distortion and increased torque ripple. The method analyzes the retention characteristics of the positive and negative regions of the three-phase stator current under steady-state operating conditions to construct a fault location function, and combines auxiliary variables to accurately distinguish between single-power and dual-power device open-circuit faults. This invention enables rapid location and accurate identification of complex open-circuit faults such as those in opposite phases on the same side or in opposite phases on opposite sides. It offers advantages such as high diagnostic accuracy, strong ability to distinguish mixed faults, and non-invasiveness, making it suitable for motor drive systems with high requirements for operational reliability and fault tolerance.

The application discloses a variable working condition cross-component causal coupling modeling and fault diagnosis method and device, and relates to the technical field of rotating machinery fault diagnosis. The method comprises the following steps: collecting and preprocessing multi-component signals under variable rotating speed working conditions of a rotating machinery; based on multivariate Granger causal modeling, prior information and dynamic disturbance information are fused to construct a dynamic causal diagram; a double-view structure of a main view of the dynamic causal diagram and an auxiliary view of a correlation diagram is constructed, multi-scale coupling features are extracted through a multi-order spectrum filter and an attention mechanism, a symmetric InfoNCE contrast learning loss and a supervised classification loss are combined to optimize and train a model, and fault classification is realized. The device is correspondingly provided with signal acquisition, dynamic causal diagram construction, feature fusion, model training and fault prediction modules. The application improves the accuracy of fault feature representation and the robustness of diagnosis under variable working conditions, is suitable for complex industrial scenes with multi-component coupling and frequent rotating speed switching, and has strong engineering practicability.

This invention provides a method for determining the stability of simply supported and fixed beams. The method includes: establishing a system of equilibrium differential equations for an elastic beam and determining the simply supported boundary conditions; performing numerical integration based on the equilibrium differential equations and the simply supported boundary conditions to obtain the shapes and corresponding parameter information of all simply supported and fixed beams; measuring the actual arc length and actual support distance of the simply supported and fixed beam to be determined; determining the corresponding moment-rotation curve based on the actual arc length, actual support distance, and the shapes and corresponding parameter information of all simply supported and fixed beams obtained from numerical integration, and determining the critical value of the fixed-end rotation angle based on the moment-rotation angle curve; measuring the actual value of the fixed-end rotation angle of the simply supported and fixed beam to be determined, and determining the stability of the simply supported and fixed beam to be determined based on the relationship between the actual value of the fixed-end rotation angle and the critical value of the fixed-end rotation angle. This invention solves the technical problem of complex and computationally intensive stability determination processes for simply supported and fixed beams in the prior art.

The present application belongs to the technical field of power supply and distribution. A parallel three-level inverter modulation method, system, product, medium and equipment are proposed, which equivalent double parallel three-level inverters as a whole five-level inverter, inject zero sequence components to the initial three-phase reference signal to obtain the reference signal, identify the resultant vector through rounding and remainder operation, and then adjust the reference signal according to the sum of the three-phase state of the initial resultant vector to output a five-segment switching sequence, and then decompose the equivalent five-level reference signal into two sets of three-level reference signals, allocate the reference signals by dividing the half-carrier period and compare them with the triangular carrier to obtain a three-level vector sequence combination. The present application realizes the comprehensive optimization of common-mode voltage, zero-sequence circulating current and output current ripple, avoids complex sector judgment and duty cycle calculation, and reduces the implementation complexity and computational burden.

This invention relates to the field of turbomachinery technology, and provides a geometric construction method and system for a two-dimensional blade profile in tandem, comprising: using the pressure surface profile of the front row of blades as a reference, at the starting point... P End point of front pressure surface T PS An arc length coordinate system is established between the points, and a channel width function is defined. The channel generation segment profile of the rear blade suction surface is generated by offsetting along the outer side of the normal at each point. A free-form segment profile is then constructed that smoothly connects to the channel generation segment, resulting in the complete rear blade suction surface. Subsequently, the rear pressure surface profile is generated by offsetting along the inner side of the suction surface normal according to a preset thickness distribution function, and smooth leading and trailing edge connection curves are constructed respectively, completing the two-dimensional airfoil structure of the rear blade. This invention combines the slit channel width distribution with the rear blade suction surface generation process, ensuring the geometric continuity of the channel segment while improving the freedom, parameterization, and geometric adjustability of the airfoil design, facilitating aerodynamic design, optimization design, and engineering applications.

This invention relates to the field of weld defect type identification technology. Existing weld defect detection methods fail to achieve intelligent and efficient detection due to the diverse types of weld defects. This invention provides a low-cost self-learning neural network design method for ultrasonic detection of weld defects. It performs high-dimensional spatial domain feature representation on the initial one-dimensional ultrasonic signal, enriches the feature expression of weld defect data, selects the feature domain with better performance, constructs an adaptive scaling network for weld defect detection, and uses a multi-objective, training-free network search and evaluation method to iteratively search and evaluate candidate networks for weld defect detection, obtaining a balanced solution on both network classification accuracy and parameter quantity. Ultimately, it achieves the selection of a weld defect type detection network with superior overall performance without any training.

This invention relates to the field of aero-engine technology and discloses a Simpack-based method for analyzing the misalignment vibration of aero-engine blades with bosses. While ensuring analytical accuracy, it improves computational efficiency by simplifying the modeling process and establishes a clear mapping relationship between parameters and responses, thus providing reliable technical support for vibration control of aero-engine bladed disk systems. The method includes the following steps: establishing finite element modal analysis models of all boss blades and disks, and performing free modal calculations; using Simpack modal condensation to establish blade-disk reduced flexible body models of all boss blades and disks, and then assembling them to form a complete blade-disk coupled dynamic analysis model of the aero-engine; subsequently, simulating the frictional vibration reduction effect between boss blades by establishing pre-compressed spring damping units or custom nonlinear spring units between the bosses of adjacent boss blades; and simulating the interference fit relationship between bosses by using the spring pre-compression amount.

The present application relates to the field of remote sensing hydrological monitoring and river dynamics parameter inversion, and specifically discloses a river flow estimation method for remote sensing water body extraction and river width inversion, which utilizes the complementarity of synthetic aperture radar images and multispectral optical images to construct a water body extraction process of adaptive threshold segmentation on the SAR side and a water body extraction process on the optical side; after obtaining the water body area of the target river section, the average river width is calculated by using the water body area-center line length ratio to weaken the local width measurement error caused by boundary sawtooth and mixed pixels; then, the observed flow is used to calibrate the power function model to form a flow inversion model for new images; and according to the rule of overlapping optical images first on the same day and SAR images for filling in missing data, time series fusion is realized to obtain all-weather and continuous flow estimation results. The present application reduces the dependence on ground stations and hydraulic facilities, and is suitable for flood warning, water resource allocation and river dynamic monitoring.

The application provides a stress adjustment system and method for a steel-concrete joint of a hybrid tower wind turbine, wherein the system comprises: a load acquisition module for setting a composite sensing network to acquire stress characteristics of the steel-concrete joint; a data processing and decision module for preprocessing the stress characteristics to obtain real characteristics, inverting stress values of each adjustment point based on a mapping relationship database of operating loads and stress distributions constructed through a finite element mechanics model, and comparing the stress values with a preset threshold to calculate a target tensioning force; a prestress control execution module for independently adjusting the stress of each adjustment point using a distributed tensioning device based on the target tensioning force; and a feedback calibration module for monitoring the adjustment result and triggering calibration. The application effectively offsets dynamic stress concentration at the joint, reduces the risk of concrete cracking and steel-concrete separation, and significantly improves the operation safety of the hybrid tower structure.

This invention discloses a battery box, including a cover and a box body. The cover includes a first cover shell upright plate, a second cover shell upright plate, and a cover shell flat plate, which are welded together to form the cover shell. A thin aluminum plate is placed inside the cover shell and the box body. Open-cell aluminum foam is filled between the thin aluminum plate, the steel plate, and the cover shell. A battery pack is installed inside the box body. Outer edges are welded to the upper part of the steel plate, the lower part of the first cover shell upright plate, and the second cover shell upright plate, and round holes are provided on the outer edges. Each connecting screw connects the cover and the box body through the corresponding round holes. A heat insulation layer is added to the cover and the box body. The heat insulation layer is composed of a thin aluminum plate bonded to polyurethane foam. This ensures reliable operation of the battery box. The energy absorption capacity of the open-cell aluminum foam mainly depends on its density ρ. f Thickness t f Its mechanical properties. In order to fully absorb the energy of the explosion of flammable gas in the battery box, a corresponding analytical process is provided to select open-cell aluminum foam with appropriate parameters.

This application relates to an integrated fiber optic dual-parameter monitoring system for seawater metal-air batteries, its monitoring method, and its application, belonging to the field of battery monitoring technology. The monitoring system of this application includes a seawater metal-air battery cell, an integrated fiber optic sensing unit, and a spectral demodulation module. The seawater metal-air battery cell includes an oxygen reduction cathode, which comprises an electrode composite substrate and a catalyst layer loaded on the electrode composite substrate. The integrated fiber optic sensing unit includes a single optical fiber, on which a first fiber Bragg grating and a second fiber Bragg grating are sequentially arranged along the axial direction. The spectral demodulation module is optically connected to the optical fiber and is used to receive and analyze the wavelength signal of the reflected light. The monitoring system provided in this application utilizes a single optical fiber to achieve simultaneous monitoring and cross-sensitivity decoupling of stress and temperature dual parameters, and has advantages such as compact structure, low cost, and high measurement accuracy. It can be applied to the health status assessment and failure early warning of seawater metal-air batteries.

The application provides a frame-embedded preform integrated weaving method and a preform. The weaving method comprises the following steps: providing a frame; connecting one end of N layers of warp yarns with a loom, winding the other end of the warp yarns around the front end of the frame, folding the other end of the warp yarns, connecting the other end of the warp yarns with the loom, and forming 2N layers of warp yarns on the frame; layering the warp yarns, wefting according to a selected fabric structure, and weaving to a selected preform structure size; separating the 2N layers of warp yarns into upper and lower parts, then making the rear end of the frame pass between the upper and lower parts of the warp yarns, and continuing to weave the end fabric; disconnecting the warp yarns, connecting a frame pressing plate with the frame, clamping the preform, and obtaining a frame-embedded preform. The method realizes the integration of the frame and the preform, reduces the deformation of the fabric caused by the inconsistent tension during assembly, effectively improves the strength of the preform, clamps the warp and weft yarns of the preform wound on the frame firmly by the frame pressing plate, and reduces the possibility that the preform is detached from the frame.

The application discloses an ISAR image adaptive quantization method based on histogram entropy, and belongs to the technical field of radars. An M*N dimension ISAR amplitude floating-point data matrix model in units of dB is firstly constructed; then a quantization boundary value coordinate axis of the ISAR image quantization is constructed; then the optimal upper and lower quantization boundaries of the ISAR amplitude data are obtained; finally, the optimal quantization image is obtained by quantization based on the obtained upper and lower quantization boundaries. The application uses the entropy of the ISAR image as an evaluation index of adaptive quantization, has universal applicability, and reduces the problem of non-uniform quantization of different targets, different resolutions and different signal-to-noise ratio environments during ISAR imaging. By using the histogram entropy of the ISAR image, the calculation amount of the entropy operation of the whole image is avoided, and only the histogram needs to be quantized, so that the operation scale of the two-dimensional image is reduced to the scale of the quantization order W, and the engineering application of real-time processing is more favorable. The histogram entropy can be used for different quantization bit numbers.

The application discloses a kind of calculation methods of temporal displacement of underlying shield tunnel upheaval when foundation pit excavation causes, comprising the following steps: (1) the related size of foundation pit and underlying shield tunnel and relative position relationship are clear, establish coordinate system, construct calculation analysis model;(2) considering the characteristics of soil consolidation deformation in tunnel-soil interaction process, equivalent to elastic half-space foundation model, equivalent to Euler-Bernoulli beam of shield tunnel is placed in elastic half-space inside, combined with Terzaghi-Rendulic three-dimensional consolidation theory, using the deformation coupling condition of tunnel and soil, the temporal solution of underlying shield tunnel upheaval displacement caused by foundation pit excavation is obtained.The application does not need to determine the ground reaction coefficient or soil shear layer parameters, avoids the problem that these parameters are complex and difficult to obtain accurately in two-stage method;Fully consider the characteristics of soil consolidation deformation, can more reasonably and accurately predict the upheaval displacement size of underlying shield tunnel caused by foundation pit excavation and its development process with time.