280 results about "Transient temperature" patented technology

The invention relates to the technical field of field data acquisition, in particular to an on-line temperature self-compensation calibration method and circuit for a force measurement transmitter. The calibration method comprises the steps that a working strain gauge and a temperature compensation gauge are synchronously excited through a two-way precision constant current source, the working strain gauge and the temperature compensation gauge are consistent in material parameter and are located in the same temperature field, and output current values of the two-way precision constant current source are equal and are controlled by a high-precision reference voltage source and a sampling resistor in a closed-loop mode. According to the invention, differential signals of the working strain gauge and the temperature compensation gauge are decoupled in real time through double-path precise constant-current source excitation and synchronous ADC acquisition technologies, gradient compensation is carried out on the temperature change rate in combination with a dynamic weighting algorithm, a lag error of traditional fixed coefficient compensation in a transient temperature field is effectively eliminated, and the accuracy of temperature compensation is improved. And online self-compensation of the temperature drift of the strain gauge is realized.

The invention relates to wide-range multi-component sensor calibration equipment and a wide-range multi-component sensor calibration method. The method comprises the following steps: firstly, checking equipment parts and setting a target temperature range and a compensation model of each temperature interval; then, dynamic temperature control is started, jig deformation is monitored in real time, a transient temperature gradient suppression technology is applied, multi-physical-quantity calibration is executed, and a compensation measurement value is output; then setting multi-environment coupling calibration test conditions to simulate actual working conditions, and monitoring and recording calibration data of each physical quantity; and finally, calculating a calibration error by combining a calibration result and a reference standard value. According to the process, by precisely setting parameters and combining dynamic control, real-time monitoring and multi-physical-quantity calibration, the transient temperature gradient influence is effectively inhibited, and the measurement precision of the sensor in a complex environment is ensured; the temperature control performance is improved through the micro soaking film and the intelligent temperature control strategy, the actual working condition is simulated through multi-environment coupling testing, the accuracy and reliability of the calibration result are remarkably improved through compensation and error calculation, and guarantee is provided for precise application of the sensor.

The invention discloses a PID temperature control system and method for a semiconductor etching machine, and relates to the field of temperature control, and the system comprises a coupling relation construction module, a temperature sensing confidence module, a decoupling compensation module, a coupling relation dynamic updating module, and a transient temperature change control module. According to the invention, by constructing the coupling relation matrix and the inverse matrix thereof, decoupling control of multi-area temperature control is realized, cross interference is effectively suppressed, and the temperature control precision is improved. And a multi-point temperature measurement fusion and anti-interference algorithm is introduced, so that the temperature measurement accuracy and the system robustness are enhanced. A response residual vector is associated with a control vector, and a coupling matrix is dynamically optimized, so that the system has self-learning and model self-adaption capabilities and adapts to working condition changes. And a transient temperature change quick response mechanism is set, so that the control priority can be improved and the PID parameters can be adjusted when the temperature changes suddenly, the response speed and the control stability of the system to abnormal temperature change are remarkably improved, and the thermal uniformity and the process consistency in the etching process are ensured.

The invention discloses a cable hot-spot temperature identification method and device, terminal equipment and a storage medium. The method comprises the following steps: acquiring a steady-state temperature field reduced-order model, a cable surface temperature monitoring value and a ground surface temperature monitoring value of a power distribution network cable; obtaining an initial equivalent current based on a preset parameter space; taking the initial equivalent current as input, repeatedly executing an equivalent current iteration adjustment operation through a cable surface temperature monitoring value and a steady-state temperature field reduced-order model, stopping executing the equivalent current iteration adjustment operation when residual data is smaller than a residual threshold or the number of iterations is equal to an iteration threshold, and outputting a final iteration equivalent current; and inputting the iterative equivalent current and the surface temperature monitoring value into the steady-state temperature field reduced-order model to obtain a cable internal transient temperature field reconstruction result of the power distribution network cable. According to the invention, cable current changing in real time does not need to be monitored, the internal temperature field of the cable can be reconstructed only by monitoring the surface temperature of the cable, and the simulation accuracy of the cable temperature field is improved.

The invention discloses a new energy access lower harbor area transformer insulation performance and service life evaluation method, which comprises the following steps: firstly, establishing a wind and light storage AC / DC hybrid micro-grid equivalent simulation model, and quantifying a composite action mechanism of new energy fluctuation and harmonic characteristics on dynamic loss and hot-spot temperature rise of a transformer; analyzing a harmonic loss mechanism of the transformer in different operation modes; secondly, constructing a quay crane and field crane operation simulation model, and analyzing the harmonic characteristics of bridge crane equipment and the influence of the harmonic characteristics on the harmonic distortion rate of the power distribution network; then, on the basis of the data, a transformer hot-spot temperature dynamic calculation model is established in combination with bidirectional power flow characteristics; and finally, calculating transient temperature distribution of the transformer through a flow field-temperature field coupling method, and constructing a multi-physical field coupled insulation aging rate model to realize evaluation of the residual life of the transformer. The method solves the problem that the traditional method cannot quantify the bidirectional power flow and harmonic wave composite aging effect.

The invention discloses a method and a system for rapidly calculating a transient temperature field and a stress field of a key component of an engine, the transient temperature and the transient stress can be calculated through an algebraic relationship of a small number of variables, the calculation speed is greatly improved, the response of the temperature and the stress can be rapidly calculated under different parameter changes, and the calculation accuracy is improved. In addition, the undetermined coefficients of the rapid calculation model are obtained by fitting historical data and do not depend on accurate geometric or boundary condition description, so that the modeling process is greatly simplified, only a small number of coefficients and formulas are needed, and the modeling efficiency is greatly improved. And the data volume is extremely small, so that the method is suitable for being used on network transmission or embedded equipment, and the storage space and the data transmission pressure are greatly reduced.

The invention discloses a reclosing locking method and system based on winding hot-spot temperature fitting, and relates to the technical field of power transformer dynamic stability assessment, and the method comprises the steps: determining a target transformer, collecting parameters, building a winding current calculation model, calculating steady-state and short-circuit current waveforms, and carrying out the winding temperature rise test of the transformer, the method comprises the following steps: measuring a steady-state temperature rise value, constructing and correcting an electromagnetic heat flow coupling model, generating steady-state and transient-state temperature field data of a winding, constructing a target function of a winding hot-spot temperature, fitting simulation data by utilizing an optimization algorithm, obtaining a fitting function, calculating a winding stress value under a short-circuit working condition in real time, and comparing the winding stress value with a dynamically adjusted stress limit value, so as to obtain a winding stress value. Alarm and locking reclosing are triggered according to the result, and intelligent protection of the transformer is achieved. According to the invention, through accurate parameter acquisition, model establishment, temperature field simulation, hot-spot temperature fitting and stress calculation, real-time monitoring and intelligent protection of the transformer winding under the short-circuit working condition are realized.

The invention discloses a shaft operation state intelligent prediction method based on a hybrid deep learning framework, and belongs to the field of petroleum engineering oil-gas field development engineering, and the method comprises the following steps: building a geological sequestration shaft transient temperature-pressure coupling mathematical model, and carrying out the numerical solution; constructing a double sequence feature database covering CO2 injection and leakage working conditions; adopting a parallel architecture to process the double sequence features to construct an improved double attention network; the method comprises the following steps: establishing a hybrid deep learning framework DT-DANet by coupling an improved double attention network and a time fusion Transform; and carrying out collaborative optimization training on the hybrid deep learning framework by adopting a composite loss function, wherein the output of the framework is a wellbore pressure profile, a temperature profile and phase state distribution under different time steps. According to the method, high-precision prediction of shaft multi-parameter dynamic evolution in the CO2 geological storage process is realized.

The invention discloses a method for quickly calculating transient thermal stress of a ceramic radome along a flight path, which comprises the following steps of: determining calculation input which comprises an aerodynamic thermal environment of the ceramic radome and a to-be-evaluated structure scheme; setting a circumferential discrete strategy of the ceramic radome to determine a plurality of meridian planes of the ceramic radome; constructing an aerodynamic thermal environment interpolation model, and determining a meridian plane where aerodynamic heating of the ceramic antenna housing is most strict in the whole flight process; constructing a two-dimensional feature structure model for transient heat transfer and thermal stress analysis of the ceramic radome, and determining an outer contour line of the two-dimensional feature structure model; constructing an axial thermal response calculation interval of the ceramic radome and performing interpolation calculation to obtain aerodynamic thermal environment parameters of the outer contour line at each flight moment; performing heat transfer calculation grid division on the two-dimensional feature structure model, and calculating structure transient temperature distribution of the two-dimensional feature structure model; calculating the temperature gradient of the structure based on the transient temperature distribution of the structure; and calculating transient thermal stress distribution of the ceramic radome by using the structural temperature gradient.

The invention discloses a Foster network model-based cable transient temperature prediction method and a related device. The method comprises the steps of obtaining target cable basic data, actual operation power data, actual environment temperature data and heat dissipation boundary conditions of a target cable; constructing a cable simulation model based on the basic data of the target cable; controlling the cable simulation model to perform transient simulation according to the actual operation power data, the actual environment temperature data and the heat dissipation boundary conditions to obtain a target simulation temperature curve; a target Foster network model is constructed; performing transient temperature prediction through the target Foster network model to obtain a target prediction temperature curve; target model precision is determined according to the target simulation temperature curve and the target prediction temperature curve; and when the target model precision is greater than the preset precision, determining the transient temperature of the target cable according to the target predicted temperature curve. By adopting the embodiment of the invention, the prediction error of the transient temperature is reduced.

The invention discloses a synchronous reluctance motor magnetothermal coupling rapid calculation method based on a dynamic thermal network, and belongs to the technical field of motors. Comprising the following steps: calculating motor loss by adopting a finite element electromagnetic field model, and calculating a convective heat transfer coefficient by adopting a finite element fluid field model; constructing a three-dimensional thermal network comprising conduction, contact, convection thermal resistance, thermal capacity and a heat source, and solving to obtain an average temperature and a boundary temperature of component nodes; constructing a sub-domain temperature field calculation model of the heat source component, and calculating temperature distribution in combination with boundary conditions; introducing average temperature compensation thermal resistance and carrying out dynamic correction; carrying out magnetothermal coupling iteration, and updating the loss and the temperature until the precision is met; and introducing maximum temperature compensation thermal resistance into the thermal network, and solving to obtain an average temperature and a maximum temperature transient temperature rise curve of each component. Based on the technical means of combining electromagnetic field and fluid field finite element simulation with thermal network and subdomain temperature field calculation, efficient calculation of magnetothermal coupling of the synchronous reluctance motor is achieved.

The invention relates to the technical field of aero-engine tests, and discloses a temperature distortion test device and a design method thereof. An annular space between the inner casing and the inner casing forms a mixing space; the connecting assemblies are connected with the outer casing, and part of the connecting assemblies form a conveying assembly; a first input port is formed in one side wall surface of an injection part of the conveying assembly, and a second input port is formed in the other side wall surface; the gas conveying pipeline is connected with the connecting part; according to the invention, the response speed of the control valve is relatively high, so that the gas conveying pipeline can sensitively convey high-temperature gas flow, transient temperature distortion of the temperature distortion test device can be realized, and in addition, the comprehensive distortion effect can be greatly improved in a downstream and countercurrent combined mode; performance indexes of the temperature distortion test device meet test requirements of transient temperature distortion, so that the temperature distortion test device can realize transient temperature distortion by adopting a high-temperature airflow injection mode.

The invention provides an automatic chemical reaction monitoring device and method. An automatic chemical reaction monitoring device comprises a chemical reaction unit, a temperature and pressure monitoring unit, a data processing unit, a video recording control unit and a synchronous clock unit, data are collected in real time through a high-precision temperature and pressure sensor, and a dynamic threshold value calculation module generates a self-adaptive threshold value based on a reference value and data fluctuation characteristics; the temperature and pressure combined trigger module identifies the jump characteristics and triggers video recording, and the synchronous clock unit realizes millisecond-level time synchronization of multi-source data. The method comprises the steps of reagent injection, temperature and pressure monitoring, dynamic threshold calculation, jump identification triggering, data synchronous recording and the like. The embodiment shows that the device can accurately capture transient temperature and pressure changes of the chemical reaction, the anti-interference capacity is remarkably improved compared with traditional fixed threshold triggering, and the device is suitable for chemical reaction mechanism research and industrial process control needing to monitor temperature and pressure coupling changes in real time.

The invention provides a temperature rise determination method for gas insulated power transmission equipment, and the method comprises the steps: obtaining a two-dimensional multi-section model corresponding to the gas insulated power transmission equipment composed of a plurality of standard sections based on the structure parameters of the gas insulated power transmission equipment; based on the two-dimensional multi-section model, establishing a two-dimensional multi-section field-circuit coupling model through a Kirchhoff voltage and current equation and an electromagnetic field control equation; through the two-dimensional multi-section field-circuit coupling model, eddy current field distribution and ohmic loss of the gas-insulated power transmission equipment can be rapidly determined. Taking the ohmic loss as heat source excitation of a heat flow coupling field control equation, and solving through a finite volume method to obtain radial temperature rise in the gas insulated power transmission equipment; evaluating the thermal stability of the gas-insulated power transmission equipment by combining the temperature rise of the interior of the gas-insulated power transmission equipment along the axial direction under different working conditions; according to the technical scheme, the accuracy and efficiency of transient temperature rise analysis of the gas insulated power transmission equipment can be effectively improved.

The invention discloses a temperature control system and method of a micro-fluidic chip, and relates to the technical field of micro-fluidic temperature control, and the method comprises the following steps: in the manufacturing process of the micro-fluidic chip, embedding topological insulator nanowires into a substrate in a directional arrangement mode to form a pre-locking array, and meanwhile, generating an anisotropic heat conduction network under the continuous action of a sound-magnetic field, a topological vortex invariant is calculated, and a heat conduction weight coefficient is generated; arranging a fluorescent layer on the surface of a micro-reaction cavity of the anisotropic heat conduction network, collecting a fluorescence lifetime attenuation curve in real time, and calculating a transient temperature value and a temperature change rate according to a heat conduction constraint variation model and a heat conduction weight system; nonlinear feed-forward compensation power is calculated according to the transient temperature value and the temperature change rate, feedback compensation power is calculated in combination with a deviation field of the target temperature and the real-time temperature, and a compensation power instruction is generated; according to the method, the thermal pilot frequency domain filtering function is constructed through the compensation power instruction, so that the uniformity and response speed of thermal response are improved.

The invention discloses a method for constructing an unsteady thermal stress analytical model of a through silicon via, which belongs to the technical field of microelectronics and comprises the following steps of: establishing a transient thermal conduction equation and a temperature field boundary condition of the through silicon via; solving the transient heat conduction equation to obtain a transient temperature field analytical model, and obtaining transient temperature field distribution according to the transient temperature field analytical model; establishing an equilibrium equation and a mechanical boundary condition based on a working environment of the through silicon via, and determining a displacement field of the through silicon via and a basic form of a stress field analytical model according to the equilibrium equation and the transient temperature field analytical model; coupling the transient temperature field and the transient stress field according to the mechanical boundary condition and the basic form of the displacement field and stress field analytical model to obtain an unsteady thermal stress analytical model; and obtaining the unsteady thermal stress according to the unsteady thermal stress analytical model. According to the method, the problem that temperature field distribution and thermal stress change along with time are not considered in a thermal stress analysis model is solved, and real-time prediction of thermal stress distribution in the silicon through hole is realized.

The invention belongs to the field of data science and machine learning, and constructs a prediction system fusing a convolutional neural network (CNN), a long-short-term memory network (LSTM), a seasonal autoregressive integral moving average model (SARIMAX) and a data-driven modeling method in order to solve the problem of battery temperature prediction. The system focuses on analyzing transient temperature change during fast charging of the battery and a temperature evolution rule caused by aging, an exclusive data feature extraction and fusion strategy is formulated for different working conditions, and model parameters are optimized. Key performance indexes such as prediction accuracy, model robustness and working condition adaptability are remarkably improved, and the method has a wide application prospect and an important practical value in thermal management of the battery of the electric vehicle.

The invention discloses a rapid design method and system for a turbine blade, electronic equipment and a storage medium, and the rapid design method comprises the steps: firstly, obtaining boundary conditions of a gas side and a cold air side of the turbine blade in an actual working environment based on flow heat exchange test data, and then constructing a heat exchange boundary model based on the boundary conditions; according to the method, temperature field calculation becomes a pure solid heat conduction problem, and only depends on known boundary conditions and material attributes, so that a heat exchange boundary model can be directly applied to a blade three-dimensional model for transient temperature field calculation, and CFD simulation calculation needing iterative solution is replaced; by means of the method, the most time-consuming flow field solving and flow thermal coupling iteration link in the whole analysis process is thoroughly eliminated, the calculation efficiency is remarkably improved while the calculation precision is guaranteed, a thermal-force coupling chain is cut off through decoupling calculation of the transient temperature field and the transient stress field, and the calculation efficiency is further improved.

The invention discloses an experimental device and method for positioning and artificially manufacturing fractures in a borehole and expanding the fractures. The experimental device comprises a tubular column carrier unit, and a positioning anchoring system, a mechanical fracture forming pretreatment system, a thermal shock fracturing system and a control terminal which are integrated on the tubular column carrier unit. The positioning anchoring system is used for detecting the well wall and locking the target depth and direction; the mechanical crack-making pretreatment system is used for cutting at the locking position to form an initial physical gap; the thermal shock fracturing system presets a thermal stress field through a heating assembly, and utilizes a cold shock assembly to spray low-temperature fluid to generate transient temperature difference stress to induce cracks to crack from notches and expand. And the control terminal controls the action time sequence of each system. According to the method, through the mode of mechanical drilling and thermal coupling, fixed-point and directional accurate fracture forming in a borehole is achieved, the generated fracture shape is close to that of a natural fracture, and the problems that a traditional method is inaccurate in positioning, uncontrollable in shape and large in damage to the whole sample are solved.

The invention relates to the technical field of refrigeration air conditioners and automatic control, in particular to a fixed frequency compressor group control energy regulation system based on outdoor temperature and humidity coupling, which comprises a data acquisition unit, a reheating demand judgment unit and an anti-icing protection control unit, a data acquisition unit acquires outdoor temperature and humidity coupling data and return air temperature data of all compressors through an outdoor temperature and humidity sensor and a return air temperature sensor, and a reheating demand judgment unit implements temperature feedforward control based on outdoor temperature and humidity and sets an adjustable limit level to constrain the input proportion of the compressors. When the compressors are fully input and the humidity exceeds the standard, the moisture content of indoor, target and outdoor air is calculated, the reheating requirement is judged by combining the transient temperature when the integral speed of the cooling and dehumidification PID controller and the adjustable limiting level and the floating gear are adjusted according to the moisture content, and the anti-icing protection control unit periodically monitors the return air temperature and takes measures. The problems that temperature and humidity control of a traditional system is not coordinated, and anti-icing protection is not accurate are solved.

The invention relates to the technical field of non-contact temperature measurement, in particular to a transient temperature field measurement method, system and device and a medium, and the transient temperature field measurement method comprises the steps: synchronously collecting an original spectral signal and an original grayscale image of a transient temperature field; discretization processing is carried out on the corrected spectrum, a theoretical radiation spectrum corresponding to each temperature element is obtained, an image gray value-radiation brightness mapping relation is established, and temperature element weight initial distribution is obtained; optimizing by using an optimal solution algorithm to obtain an optimal temperature primitive weight; and inverting the temperature field by using the optimal temperature primitive weight and the histogram of the original grayscale image to obtain a final fusion image of the transient temperature field. According to the method, the dynamic reconstruction of the two-dimensional temperature field of the explosion fireball is realized by constructing the temperature primitive model and combining nonlinear least square optimization and image mapping of the image detector, and the problems of large single-point inversion error and low spatial resolution of the transient high-temperature field are solved.

The invention relates to the technical field of temperature early warning, and discloses a JP cabinet bus connection point temperature early warning method and device, and the method comprises the steps: collecting the voltage drop time sequence data of a JP cabinet bus connection point, and carrying out the wavelet packet decomposition of the voltage drop time sequence data, and obtaining a conduction characteristic coefficient; performing contact resistance prediction based on the conduction characteristic coefficient to obtain a contact resistance value, and calculating a transient temperature rise characteristic value based on the contact resistance value; a temperature early warning threshold value is calculated based on the transient temperature rise characteristic value and the current change rate, and a temperature early warning signal is generated based on the temperature early warning threshold value, the change characteristics of the contact interface conduction state on different time scales can be effectively captured, and compared with a simple time domain analysis method, the time domain analysis method has the advantage that the accuracy is high. The identification precision and the anti-interference capability of the weak signal change are improved, the problem of insufficient adaptability of a fixed threshold value method under a dynamic load condition is effectively solved, and the accuracy of temperature early warning is further improved.

The invention relates to the technical field of power supply or power distribution circuit devices of power systems, and discloses a power distribution loop self-reset state control system based on thermal parameter feedback, which comprises a thermal parameter acquisition module used for acquiring a physical heat dissipation temperature sequence of a power supply node after tripping; the historical load mapping module is used for calculating a closing transient temperature rise estimated value according to the load characteristic data within 24 hours before tripping and generating a dynamic correction value of a heat dissipation slope judgment boundary; the logic arbitration module is used for calculating the deviation degree of the heat dissipation slope of the double-window sampling sequence and judging whether the deviation degree is converged into a heat dissipation slope judgment boundary updated according to the dynamic correction amount or not; according to the invention, through a closed loop arbitration mechanism of a heat dissipation characteristic slope, a physical heat dissipation steady state inflection point is identified, a maloperation risk caused by environment thermal resistance drift and closing inrush current impact is eliminated, and power supply continuity is guaranteed.

The invention belongs to the technical field of thermal equipment monitoring, and particularly relates to a boiler wall surface stress monitoring system and method based on reverse heat conduction calculation. The problem that a traditional monitoring method is slow in response and large in error under the rapid variable working condition is solved. Boiler wall surface temperature data are collected in real time through a high dynamic response temperature sensor array, and after smooth processing is conducted through a Savitzky-Golay filter, a three-dimensional transient temperature field is reconstructed through a finite volume method and a space propulsion method. And further, thermal stress and pressure stress are calculated in combination with material parameters, and equivalent stress is obtained by adopting a von-Mises criterion. The system realizes a grading early warning mechanism, can automatically adjust boiler operation parameters according to the stress overrun degree, forms a monitoring-evaluation-control closed loop, and provides technical guarantee for safe operation of the boiler.

The invention relates to the technical field of detection, in particular to a lithium battery tab welding quality detection method and device.The method comprises the steps that non-contact electromagnetic excitation is applied to a lithium battery tab welding area, vibration signals and temperature signals are collected, an original vibration data set is mapped to a continuous space on the surface of a tab, and a curvature distribution diagram is generated; converting the curvature distribution map into a feature point set comprising a cluster structure, calculating a centroid coordinate and divergence of each cluster in the cluster structure, and generating a defect feature vector; constructing a defect type model according to the defect feature vector, and combining the transient temperature set with an output result of the defect type model to generate a heat effect feature vector; and performing multi-layer perceptron neural network processing on the heat effect feature vector to generate an evaluation result including the quality grade of the welding point. Complex defect types can be distinguished, the quality grade can be accurately evaluated, and the defects that an existing machine learning method is insufficient in feature extraction and low in classification precision are overcome.

The invention relates to the technical field of laser manufacturing and intelligent manufacturing, in particular to a residual stress and deformation prediction method for a laser directional energy deposition TA15 alloy component, and the method comprises the following steps: constructing a thermal-metallurgical-mechanical multi-physics field coupling model; firstly, a transient temperature field model comprehensively considering heat conduction, convection and radiation effects in the laser directional energy deposition process is established based on the Fourier heat conduction theory; then, a metallurgical model is established based on the phase change principle, finally, a multi-stage phase change kinetic model is established, and diffusion control type and non-diffusion type transformation mechanisms are considered at the same time; a phase change kinetic model is introduced into a sequentially coupled thermal-mechanical framework, so that multi-scale integrated prediction from microstructure evolution to macroscopic stress distribution is realized; and a theoretical basis is provided for microstructure regulation and control and residual stress optimization of the TA15 alloy LDED process.

The invention relates to an equivalent modeling establishment method for a winding in a slot of an outer rotor permanent magnet synchronous motor. The method comprises the following steps: S1, obtaining winding parameters of the outer rotor permanent magnet synchronous motor; s2, performing equivalent treatment on copper, air, insulation and enameled wires existing in a single winding; s3, calculating a single equivalent heat conductivity coefficient; s4, stacking according to the single winding in the S2, and calculating the equivalent heat conductivity coefficient of the whole slot winding; and S5, carrying out equivalence on the equivalent heat conductivity coefficient of the whole slot winding obtained in the step S4 and slot insulation again to obtain an equivalent slot heat conductivity coefficient of the whole model, and completing equivalent modeling of the winding in the slot of the permanent magnet synchronous motor. The method has the advantages that materials, including copper, insulation, air, enameled wires and the like, of the winding in the groove are equivalent to the variable-heat-conductivity-coefficient conductor, the heat conductivity coefficient and the heat flux density of the equivalent model are calculated, and meanwhile, the three-dimensional temperature field global simulation model is established, so that the transient temperature field distribution of the outer rotor permanent magnet synchronous motor is more accurate.

The invention belongs to the technical field of power semiconductor devices. The invention provides a SiC MOSFET surge current transient electrothermal coupling failure modeling method. A real packaging three-dimensional structure model is established, and material parameters are defined; dividing grids, constructing a current and solid heat transfer module, applying surge waveform data and realizing real-time coupling; carrying out transient solution to obtain temperature data, extracting a hot spot area and comparing thermodynamic critical parameters of the material; and establishing a multi-class failure mechanism model, and outputting a failure prediction result and reliability evaluation. The method is high in structural reduction degree, transient temperature rise and hot spot distribution can be accurately simulated, the problems that modeling is not accurate, transient electrothermal coupling analysis is lacked and a real failure mode cannot be reflected in the prior art are solved, the failure position, mode and threshold value can be accurately predicted, the method is suitable for reliability evaluation under the multi-surge condition, and the method is suitable for popularization and application. And the method has engineering application value and research significance.

The invention belongs to the technical field of high-efficiency rectifier thermal management, and provides a SiC device-based high-efficiency rectifier thermal management method, which comprises the following steps of: acquiring temperature distribution of a SiC device in a high-efficiency rectifier under a full-load condition, and acquiring a transient temperature rise area and a steady temperature rise area by analyzing a temperature change range; the global voltage and the local voltage of the SiC device are collected, whether a global avalanche phenomenon occurs or not is judged by comparing the change rate of the global voltage with a typical value, if yes, a thermal-electric coupling coefficient is calculated through the local voltage and the temperature, an avalanche breakdown source candidate grid area is extracted, and a local avalanche origin point is positioned; determining the specific position of an avalanche breakdown origin point; and outputting a space overlapping degree according to the thermal-electric coupling coefficient and the space overlapping proportion, judging whether transient temperature rise is caused by an avalanche breakdown phenomenon, and if the transient temperature rise is caused by avalanche breakdown, triggering avalanche breakdown protection optimization.

The invention discloses a test method for a strain clamp, and the method comprises the steps: carrying out the crimping and drainage plate assembly of the strain clamp, and fastening a bolt on a drainage plate to a preset initial torque value through a digital display torque wrench; measuring the contact resistance of a drainage plate of the strain clamp; arranging a T-shaped thermocouple at a monitoring point position of the strain clamp; sequentially applying currents with different percent calculated current-carrying capacities to the strain clamp through a large current generator, and recording transient temperature rise data corresponding to each monitoring point position; and measuring the contact resistance and transient temperature rise data under different bolt torques under the current of each percentage calculation current-carrying capacity. According to the invention, the actual working state of the strain clamp under different drainage plate assembly conditions can be simulated, the bolt torque of the strain clamp is taken as an independent variable, the contact resistance between the drainage plates under different torques is measured, and the overall temperature distribution of the clamp is measured through the temperature measurement probe, so that the test accuracy is improved. Therefore, real-time measurement of three kinds of data of bolt torque, contact resistance and wire clamp temperature rise is realized.