47results about How to "Avoid iterative calculations" patented technology

The invention relates to a method for dynamically controlling the furnace temperature of a heating furnace based on time sensitivity. The method comprises the following steps: (1) dynamically calculating the minimum in-furnace time of a plate blank according to the in-furnace position and discharging rhythm of the plate blank, the heating capacity of the heating furnace and the movement information maximum value of a stepping beam; (2) retrieving the specific heat capacity of the heat conductivity of the plate blank according to the actual in-furnace temperature of the plate blank to obtain physical plate blank parameters corresponding to the actual temperature of the plate blank; (3) calculating average physical parameters of the plate blank in each section; (4) predicting the temperature of the plate blank reaching the section end, and calculating the furnace temperature sensitivity of the plate blank; (5) calculating the maximum temperature rise rate of the plate blank under the condition of different furnace temperatures according to the thermal expansion coefficient, stress and elastic modulus of the plate blank; (6) establishing an optimum furnace temperature setting target function, and then controlling the furnace temperature according to the optimum furnace temperature setting target function, wherein the constraint condition is an equivalence relation established according to the steps (4, 5 and 6). According to the method, the temperature rise rate of the furnace temperature can be dynamically controlled, so that over-heating or insufficient soaking of the plate blank is avoided.

The invention relates to a linear real-time estimation method of a conductivity resistance-capacitance network parameter, belonging to the technical field of solution conductivity soft measurement. The method is characterized by comprising the following steps of: converting the measurement of solution conductivity into the parameter estimation of an equivalent resistance-capacitance network: on the basis of a mathematical model between a square wave excitation signal, a response direct-current voltage signal and two resistance and capacitance parameters of the equivalent resistance-capacitance network, carrying out multi-element polynomial fitting on the non-linear model off line; adopting an alternating-current square wave excitation resistance-capacitance network of various frequencies by taking the existence of various uncertainties into account during on-line measurement; meanwhile, establishing an over-determined equation set by utilizing the off line fitted multi-element polynomial model; and obtaining the real-time estimation of a resistance-capacitance parameter through a Gauss elimination finite step arithmetic operation and a radical operation of quartic equation solvingon the basis of linear least square principle. The method has the advantages of higher estimation speed and stronger anti-jamming capability and is suitable for the on-line real-time accurate measurement of the conductivity industry.

The invention discloses a method for evaluating the overturning risk of a train crossing a bridge based on the vibration mode superposition method, which includes: establishing the motion equation of the vehicle system, establishing the bridge system motion equation based on the vibration mode superposition method, establishing a simplified wheel-rail contact model, establishing The overall motion equation of the vehicle-bridge system. Based on the simplified wheel-rail contact model, the iterative calculation of the wheel-rail interaction force is avoided, which provides a basis for the motion equation of the combined vehicle system and bridge system; the overall motion equation of the vehicle-bridge system avoids the separate iterative solution of the motion of the vehicle system and bridge system The equation realizes the synchronous solution of vehicle and bridge response, and improves the calculation efficiency of vehicle-bridge system response. The invention effectively reduces the calculation amount of the response analysis of the train-bridge system under the action of transverse wind, and can quickly evaluate the overturning risk of the train crossing the bridge.

The invention discloses a hypersonic speed super-combustion stamping engine real-time model. A simplified shock wave angle calculation method is adopted for the real-time model; an aircraft forebody and a super-combustion stamping engine air inlet are further regarded as an integrally-coupled forebody / air inlet; air flow in an isolation segment is regarded as uniform cross-section friction pipe flow; the volume effect of a combustion chamber is considered, and the combustion chamber is regarded as a cavity; an engine tailpipe and an aircraft afterbody are integrally coupled, and flow of fuel gas in the coupled body is regarded as variable cross section friction pipe flow; accordingly a combustion chamber outlet parameter is represented by a first-order ordinary differential equation based on a volume dynamic principle. The invention further discloses a simulation method of a hypersonic speed super-combustion stamping engine and a control law design method, compared with the prior art, the dynamic process of the hypersonic speed super-combustion stamping engine can be accurately reflected, a solution is easy to obtain, and the real-time property is better.

The invention discloses a discrete-state event-driven simulation method for power electronics hybrid system simulation. Based on the hybrid characteristics of power electronics systems, simulation methods are respectively designed for continuous states and discrete events coexisting in power electronics systems. The simulation The method includes: a flexible adaptive algorithm with variable order and step size, and an event-driven mechanism that automatically triggers simulation calculations by discrete events; the continuous state is described by the state variable method, and discrete events are defined as the trigger source of simulation calculations. The discrete-state event-driven simulation method for power electronic hybrid system simulation disclosed by the invention solves the problems of large amount of calculation and time-consuming simulation of complex power electronic systems under the premise of ensuring accuracy.

The invention discloses a method for assessing the life of a modular multilevel converter, comprising the following steps: reading the annual temperature data of the natural environment in which the MMC operates and the power data injected into the MMC; analyzing and calculating the IGBT and Diode currents of the MMC sub-modules The average value and effective value; calculate the average power loss P in the fundamental frequency period of the MMC sub-module IGBT and Diode loss,T and P loss,D ;Use the Foster network model to calculate the average temperature rise T of the semiconductor device in the operating frequency cycle ja , to obtain the value T of the average junction temperature of the IGBT module (IGBTmodules, IGBTs, including IGBT and Diode) j ; According to the IGBTs average junction temperature correction and fitting calculation IGBTs loss; calculate the maximum value of the operating frequency cycle junction temperature, and count the annual fundamental frequency junction temperature cycle; statistics the annual low-frequency junction temperature fluctuation information; use the Bayerer life model to calculate semiconductor devices Number of failure cycles N of fundamental frequency and low frequency f , combined with the operating conditions to obtain the MMC life. The invention can reliably predict the life of the MMC, can effectively improve the calculation speed of prediction by obtaining the analytical expressions of the current and the junction temperature, and has the characteristics of engineering practicality and the like.

The invention provides an oil deposit well pattern and injection-production scheme optimum design method based on a balanced water drive idea. The method comprises the steps of 1, collecting and arranging block geological and development related data; 2, setting optimizing related parameters, and completing the well pattern and injection-production optimization preparation work; 3, adopting an oildeposit engineering method, predicting the displacement condition on each direction under current well location and injection-production parameters and performing quantitative evaluation; 4, adoptinga global random search algorithm, optimizing and generating novel well location / injection-production parameters, and predicting and evaluating the displacement condition in each injection-productiondirection under novel well location injection-production parameters; 5, arranging the optimization result, forming a well pattern injection-production design scheme, and performing on-site implementation. According to the method, the water drive development index calculation method built on the basis of the oil deposit engineering idea is combined with the optimization theory, the global random search algorithm is adopted for automatic solving, the calculation efficiency is ensured while the well pattern and injection-production scheme matched with the actual oil deposit is obtained, and the oil deposit recovery efficiency is improved.

Provided are a method for simulation modeling of a variable crown elevation tailwater tunnel water turbine regulating system and a model. The method comprises a step 1) of establishing a water turbine speed regulator mathematical model which comprises a water turbine speed regulator, namely a proportion integration differentiation (PID) regulator model, and an electrical-hydraulic servo system model; a step 2) of establishing a water turbine mathematical model; a step 3) of establishing a water conveyance system mathematical model, which concretely comprises the steps of performing segment handling on a water conveyance system, taking a water turbine as the boundary to divide the whole water conveyance system into a pressurized water conveyance system and a variable crown elevation tailwater system; respectively performing pressurized water conveyance system modeling and variable crown elevation tailwater system modeling; and obtaining a mathematical model of a whole water conveyance system according to the two mathematical models; and a step 4) of obtaining a simulation model of the whole variable crown elevation tailwater tunnel water turbine regulating system by combination with the water turbine speed regulator mathematical model established in the step 1), the water turbine mathematical model established in the step 2) and the water conveyance system mathematical model established in the step 3). The model established according to the method is small in calculated amount, the accuracy is high, and the stability is good.

The present invention provides a method and system for locating the sound source of an equipment failure. The collected equipment sound signal is used as the signal to be analyzed, the signal to be analyzed is subjected to Fourier transform, and the fast spectral kurtosis index of the signal to be analyzed is calculated according to the transformation result. The fast spectrum kurtosis index determines the result of fault feature frequency selection; calculates the cross-spectrum matrix and the delay sum guide response according to the fault feature frequency selection result and the signal to be analyzed, and obtains the delay sum beamforming imaging result of fault frequency selection; the delay sum And the beamforming imaging results are input into the trained two-channel convolutional neural network to obtain the location information of the fault sound source. The invention has the advantages of good real-time performance, high positioning accuracy, strong generalization ability and the like.