294 results about "Time constant" patented technology

The invention discloses a cross-system fault diagnosis method and system combined with multi-dimensional anomaly detection, and relates to the technical field of fault diagnos.The method comprises the steps that a graph neural network with a liquid time constant network unit as a node is constructed through a dynamic topology dependency relationship and a multi-dimensional key performance index flow; each unit describes state evolution through a coupled ordinary differential equation system, and a liquid state time constant can be adaptively adjusted. A time back propagation algorithm is adopted to train a model to learn a normal behavior track contour reference, and anomaly is detected through a dynamic time warping distance. And determining a fault propagation path and a root cause through anti-fact intervention and forward integral solution. And generating an optimal diagnosis action sequence in a liquid graph neural network simulation environment, and calculating a reward value based on execution efficiency, accuracy and a repair effect to carry out strategy optimization. The abnormal detection accuracy and the root cause positioning precision are improved, the fault repair time is shortened, the operation and maintenance cost is reduced, and an intelligent fault diagnosis solution is provided for a complex information technology system.

The invention discloses a thermal error prediction method for a spindle system of a high-speed precision machine tool under an inclined working condition, and develops a comprehensive thermal error compensation method for the spindle system of the high-speed precision machine tool running under the inclined working condition by utilizing error mechanism analysis. The thermal error is modeled as an exponential function which depends on the steady-state thermal error, the time constant of the thermal error balance process and the working time, derivation of the exponential function is supported by error mechanism analysis, and the exponential function is used for accurately identifying the time constant of the steady-state thermal error and the time constant of the thermal error balance process through thermal-structural interaction. Influences of inclined working conditions are incorporated into a quasi-static mechanical model of the bearing, and the problems of bearing heating and changes of axial and radial rigidity are solved. The invention further discloses a thermal error compensation system.

The invention provides a multi-mode control method and system for a brushless doubly-fed motor, and relates to the technical field of motor control, and the method comprises the steps: extracting torque-rotating speed slopes and dynamic response time constants of two points based on a steady-state working point of a current mode and an expected working point of a target switching mode, and constructing a linear correction function; fusing an output value of the linear correction function with an optimization result to generate a modal transition compensation coefficient, and injecting the compensation coefficient into a rotor side voltage control ring based on a feedforward control channel to generate an anti-disturbance dynamic compensation control strategy; and for a non-smooth adjustment item in the dynamic compensation control strategy, performing smoothing processing on a discontinuous boundary of a control quantity by adopting a subgradient projection algorithm, verifying continuous conductivity of a control curved surface in combination with a Lyapunov stability criterion, and generating a final control instruction. According to the invention, adaptive smooth switching control of the brushless doubly-fed motor can be realized.

The invention relates to the technical field of industrial process automation control, and discloses an intelligent adjusting method for an industrial waste liquid low-temperature evaporation process, which comprises the following steps of: superposing pressure step test excitation to a vacuum adjusting valve, synchronously acquiring temperature response data flow, calculating absolute error integral and SIAE and reply time characteristics of a response curve, and calculating the temperature response data flow according to the absolute error integral and SIAE and reply time characteristics of the response curve; substituting into an inverse model to solve an equivalent process gain and a time constant of the controlled object; based on the internal model control principle, PID controller parameters are dynamically calculated and updated through the calculated gain and the time constant, a control law is reconstructed to generate an execution instruction, and the problem of control divergence of a non-linear time-varying object under model mismatch is solved through active energy feature identification and a pole assignment mechanism; decoupling control and self-adaptive adjustment of fluid viscosity sudden change and equipment scaling are achieved, and the stability and control precision of the system are improved.

The invention discloses a boiler reheater wall temperature prediction method and system, an overtemperature early warning method and system and a medium, and belongs to the technical field of safe operation of a boiler heating surface, and the method comprises the steps: collecting historical operation data, and carrying out the preprocessing; adopting a kernel principal component analysis (KPCA) algorithm to carry out screening and dimension reduction on the original variables, and selecting the first m principal component variables as model input; the method comprises the following steps: capturing short-term time data characteristics by using a closed continuous time constant (CFC) neural network, capturing a long-term dependency relationship in combination with a neural network (KAN) based on a Coriolgov-Arnold representation theorem, and constructing a CFC-KAN-based boiler reheater wall temperature prediction model; and training the optimization model, and then predicting the wall temperature prediction value of the boiler reheater. According to the method, the wall temperature of the boiler reheater can be accurately predicted, and a decision basis is provided for overtemperature early warning.

The invention discloses a server energy-saving system and method based on a lag compensation type dynamic thermal impedance model, and relates to the field of server energy saving.By collecting operation data of a server hardware bottom layer in real time, a multi-dimensional thermal-computing force coupling time sequence atlas is constructed, and based on the multi-dimensional thermal-computing force coupling time sequence atlas, a dynamic thermal impedance model is established. Calculating a heat conduction time constant of hardware in a current environment; establishing a lag compensation type dynamic thermal impedance model based on the heat conduction time constant; constructing a thermodynamic phase space according to operation data; analyzing a noise reduction evolution trajectory in combination with the lag compensation type dynamic thermal impedance model; the method comprises the steps of generating a weighted thermal resonance state vector, activating an adaptive gain MPC predictive damping scheduling strategy based on the weighted thermal resonance state vector, constructing and solving a dynamic weighted multi-objective optimization function, generating an optimal damping scheduling instruction, and thoroughly solving the fan asthma phenomenon that the fan PWM duty ratio fluctuates substantially in a sine mode under the constant computing power load.

The invention relates to the technical field of power system stability control, in particular to a new energy station transient voltage and frequency coordination stability control method, which comprises the following steps of: analyzing a transient energy evolution rule of an equivalent synchronous motor and stored energy by constructing an alternating current and direct current hybrid dynamic model and fusing with multi-time scale characteristics; based on dynamic weight matrix optimization and a multi-target coordination control strategy, self-adaptive balance of power distribution is realized; a nonlinear feedback algorithm and a real-time compensation mechanism are designed in combination with the Lyapunov theory, and voltage frequency fluctuation in a disturbance scene is suppressed; establishing a multivariable cooperative control architecture, and dynamically adjusting a power adjustment priority and an inertia time constant through coupling iterative optimization of a source storage cooperative strategy to realize adaptive compensation of a transient energy propagation path; according to the method, the dynamic stability and the anti-interference capability of the new energy station under transient impact are remarkably improved, and safe operation of a high-proportion new energy power grid is guaranteed.

The invention provides a power electronic component thermal resistance transient overload test method and system, and the method comprises the following steps: building a test platform, carrying out the initialization calibration of a test environment, and enabling the test platform to be integrated with a power drive module; the high-frequency sampling and dynamic adjusting technology is adopted, temperature, voltage and current data are collected at the sampling rate not lower than 10 kHz, the sampling interval is adjusted according to the thermal time constant, the advanced sensor and calibration technology is combined, coupling changes of temperature and electrical parameters are accurately captured, and the testing precision is improved; meanwhile, by means of a hardware synchronous clock and a rapid data processing technology, full-time tracking of rapid fluctuation of thermal resistance in the transient overload process is achieved, key characteristic parameters such as a thermal resistance peak value and response time are accurately extracted, and a reliable basis is provided for performance evaluation of components; in addition, various transient power waveforms and combinations thereof are supported, abundant transient overload working conditions are preset, a complex overload scene is simulated, and the practicability and reliability of the test are enhanced.

The invention relates to a rigid spacecraft attitude control method and system based on finite time constraint, and belongs to the technical field of spacecraft attitude control. Comprising the following steps: respectively constructing a spacecraft attitude control system model and a finite time convergence performance function containing a preset time constant; according to the finite time convergence performance function, dynamic attitude constraint is applied to the system state of the spacecraft attitude control system model; converting the attitude constraint into differential homeomorphic mapping of an unconstrained space; obtaining an error conversion variable according to differential homeomorphic mapping; and designing a virtual control law and constructing an error compensation module according to the error conversion variable, and designing an actual control input law according to the virtual control law and the error compensation module. According to the method, rapid convergence of the spacecraft attitude within the preset time is ensured, the dynamic response precision of the spacecraft in the rapid attitude maneuver process is remarkably improved, the control period delay is effectively avoided, and the power consumption is reduced.

The invention discloses a complex medium controllable source electromagnetic multi-parameter three-dimensional inversion method and system, and the method comprises the steps: carrying out the three-dimensional space discretization of an exploration region, and carrying out the multi-time iteration inversion of a discrete exploration region through initializing a multi-parameter geologic model based on a multi-parameter inversion target function, and obtaining a multi-parameter three-dimensional inversion result; wherein the multi-parameter inversion objective function comprises a data fitting constraint, a model constraint and a cross gradient constraint, and the multi-parameter model comprises resistivity, magnetic conductivity, a charging rate, a frequency correlation coefficient and a time constant; and a hexahedral mesh discrete calculation region is adopted in inversion, and a finite element linear equation set is obtained through a vector finite element method, so that multi-parameter three-dimensional forward modeling calculation is realized. According to the method, the induced polarization effect and the magnetic conductivity influence are considered at the same time, multi-parameter three-dimensional inversion is achieved, the application precision and reliability of the controllable source electromagnetic method under the complex geological condition are remarkably improved, and rich geophysical basis is provided.

The invention discloses a multi-modal robot control method and system based on space-time fusion and a liquid neural network. The method comprises the following steps: collecting asynchronous time sequence data of a multi-source heterogeneous sensor, and establishing a unified reference clock and time grid; through a neural phase-locked loop and soft-DTW, learnable synchronization is realized, and an alignment sequence, confidence and a residual error are output; after modal feature coding, fusion features are formed through confidence-gated layered space-time cross attention; a nominal control instruction is generated by the liquid neural network of the self-adaptive time constant; and the command is optimized and corrected in combination with CLF / CBF and QP, and a safe and feasible control command is output. According to the method, uncertainty caused by asynchronization, shielding and the like is effectively inhibited, the path deviation and the collision rate are remarkably reduced, and high precision, high robustness and provable safety are kept in a dynamic unstructured environment.

The invention discloses a first-order linear active disturbance rejection controller parameter setting method based on a phase margin method, and the method comprises the following steps: S1, obtaining simplified first-order inertia delay object parameters through an open-loop step response curve on site, and the simplified first-order inertia delay object parameters comprise the steady-state gain K, the inertia time constant T and the delay time tau of a controlled object; and S2, discussing and setting parameters of the controller according to conditions according to the ratio theta of the delay time tau of the controlled object to the inertia constant T. According to the first-order linear active-disturbance-rejection controller parameter setting method based on the phase angle margin method, the phase angle margin of the first-order linear active-disturbance-rejection controller is subjected to theoretical analysis, and the phase angle margin of the first-order linear active-disturbance-rejection controller and a closed-loop stable system of a controlled object is directly configured; and therefore, the problem of overshoot in parameter setting of the linear active disturbance rejection controller can be solved.

The invention relates to the technical field of industrial automation control and dynamic simulation, and discloses a centralized control console and 3D model linkage virtual-real simulation system, which comprises a control signal sampling interface, a load response modulation unit, a dynamic model evolution unit and a virtual-real closed-loop feedback unit, the load response modulation unit performs energy consumption weight accumulation on all the virtual controlled objects in transient action to generate a global time scaling factor so as to correct an inertia time constant of the system in real time; the dynamic model evolution unit introduces a hard limiting boundary by using an amplitude limiting link and calculates a process variable; the virtual-real closed-loop feedback unit extracts a control deviation signal and drives a physical instrument to generate a nonlinear damping action, and by establishing a global load modulation model based on energy constraint, a discrete control system spontaneously emerges a nonlinear hysteresis characteristic conforming to physical energy conservation under the low calculation power condition without complex fluid network solution.

The invention provides a PI-GAN-based MMT-PMSLM dynamic performance modeling optimization method, equipment and a medium, and the method comprises the steps: building an MMT-PMSLM dynamic response performance analysis model based on thrust performance, mechanical and electrical time constants, motor constants and thrust bandwidth based on the requirement of a linear servo system for high dynamic performance; based on the performance analysis model, constructing an MMT-PMSLM dynamic performance prediction model based on PI-GAN; and performing iterative optimization on the dynamic performance prediction model through a dream optimization DOA algorithm to generate optimized structure parameters. The dynamic performance modeling optimization method disclosed by the invention has the characteristics of high precision, strong generalization ability and interpretability, so that the result of optimizing the motor structure by the algorithm has high reliability.

The invention belongs to the field of electrical engineering, and relates to a dry-type transformer capacity rapid assessment method and system based on a two-section short-time small current, and the method comprises the steps: inputting a first section of small current I1 to a winding of a transformer, and collecting the winding temperature data T (t) 1 of the first section until a steady state is reached; under the condition that the power supply is not interrupted, the current is directly increased to a second section of small current I2, and the winding temperature data T (t) 2 of the second section is continuously collected until the stable state is reached again; fitting the winding temperature data T (t) 1 and T (t) 2, and outputting an index model and index model parameters; inputting the index model parameters into a power function model related to the load rate, and outputting power function model parameters; setting the load rate to be 100%, and calculating to obtain a temperature rise stable value and a time constant under the 100% rated current Ie of the transformer; and based on the GB / T1094.12 standard, comparing the average temperature rise of the winding with the maximum allowable temperature rise value, and evaluating the actual capacity and bearing capacity of the transformer. The device has the effects of saving energy, reducing consumption and improving efficiency.

The invention discloses a thermal working time lag process ADRC design method with time lag robustness. The thermal working time lag process ADRC design method comprises the steps that 1, a transfer function model of a first-order inertia time lag process of a thermal process is established; step 2, establishing a time-delay ADRC structure based on model information driving; 3, obtaining a proportional gain with expected closed-loop dynamic representation and a corresponding observer bandwidth setting rule through low-frequency approximation; step 4, scaling control parameters of the ADRC system according to the transfer function model established in the step 1, and setting default adjustment parameters of proportional gain and observation bandwidth; 5, carrying out equivalent two-degree-of-freedom conversion on the closed-loop system, analyzing the nominal stability of the ADRC system based on a double-track method, and obtaining a nominal stability domain of the control parameters; and step 6, in the nominal stability domain obtained in the step 4, according to the regularization rule of the ADRC scaling parameter and the demand of comprehensive robustness, obtaining the time constant of the low-pass filter in the compensation channel by establishing a monotonically decreasing amplitude curve of the time-delay ADRC open-loop Bode diagram.

A method for characterizing oxide defects in semiconductor devices is described. Based on time-resolved SILC data, a total number of active oxide defects and each defect's characteristics can be determined for a deeply-scaled FET device. The discrete changes in leakage current correspond to switching of a single defect. A Bayesian-inspired algorithm is utilized to extract distinct current levels and experimental data is quantized into these extracted current levels by filtering noise. The evolution of current levels corresponds to a Markov chain. The defect currents are extracted by clustering transition probabilities and absolute differences in current levels using an affinity propagation algorithm. A maximum likelihood estimator is developed to extract a base leakage current. Lastly, defect currents are used to reconstruct the experimental data and its deconvolution into activity of individual defects provides the respective time constants.

Disclosed is an integrated energy system optimized dispatching method based on a variable time constant gradient algorithm. A Markov decision making process model is established based on an economic dispatching characteristic of an integrated energy system first, and a target optimization function is established. Then, a neural network is established and trained by applying a double-delay depth deterministic strategy gradient algorithm, effective experience is determined before updating a target network, and a variable time constant is set according to a reward value of a current round and a reward value of the last round of soft update. Finally, a trained intelligent agent is used for intra-day dispatching of the integrated energy system, so as to realize optimal economic cost operation of the integrated energy system.

The invention discloses a new energy grid-connected system transient stability evaluation method based on a normal type, and relates to the technical field of stable operation of a power system, and the method comprises the steps: building a full-order model of a new energy equipment grid-connected system, and dividing fast and slow variables according to the time constant of each state variable; performing perturbation on the full-order model based on a singular perturbation method to obtain a singular perturbation system, and obtaining a simplified model of the new energy equipment grid-connected system based on the singular perturbation system; performing linear and nonlinear transformation on the simplified model based on a regular method to obtain stability manifold estimation near a dominant unstable equilibrium point of the system, and further obtaining stability domain boundary estimation; and the transient stability of the system is judged by comparing the fault trajectory after the fault is removed with the stability domain boundary estimation. According to the method, the full-process automation from system modeling to stability judgment is realized, the accuracy and efficiency of evaluation are improved, and the complexity and nonlinear characteristics of the new energy equipment grid-connected system can be effectively processed.

The invention discloses a VSG coordinated control method and device based on improved self-adaption and feed-forward compensation, and the method comprises the steps: building a model of a VSG optical storage grid-connected system, and analyzing a power angle characteristic and a frequency oscillation curve; introducing an arc tangent function to optimize a traditional adaptive control strategy, and smoothly adjusting rotational inertia and a damping coefficient; a feed-forward compensation control strategy is added, an active compensation expression and a rotor motion equation are established, a compensation coefficient and a filtering time constant are set in a coordinated mode, and configuration of a small-signal model change zero-pole pair of an active power reference value under disturbance is reconstructed; adjusting virtual rotational inertia and a damping coefficient based on the optimized adaptive control strategy, and correcting a power reference value in advance by predicting frequency fluctuation based on a feed-forward compensation control strategy; according to the method, power overshoot and frequency change deviation are effectively suppressed, smooth adjustment of rotational inertia and VSG dynamic performance optimization are realized, and the system response speed and stability are enhanced.

The invention discloses a doubly-fed wind turbine generator control parameter optimization method based on the lowest point of the frequency of a power system under low voltage ride through, and the method comprises the steps: 1, considering the influence of a wind speed, a pitch angle and a rotating speed on a capture coefficient, and solving the capture power; 2, providing a virtual synchronous machine control strategy for active compensation of the wind turbine generator, solving a transfer function between the rotating speed of the wind turbine generator and the system frequency, and deducing a power frequency response transfer function of the wind turbine generator; 3, solving the equivalent inertia time constant of the wind turbine generator based on the transfer function, considering the influence of different working conditions of the wind turbine generator in low voltage ride through, performing weighted calculation on the equivalent inertia time constant of the system, and quantifying the power frequency response characteristics of the wind turbine generator in different working conditions; 4, solving a frequency variation based on a system equivalent inertia time constant and a power frequency response characteristic; and 5, solving system trajectory sensitivity, constructing a Hessian matrix based on the sensitivity, solving a parameter optimal value by an interior point method, and raising a frequency lowest point. The calculation accuracy of the frequency variation of the power system 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 network construction type converter control parameter setting method for improving the active supporting capability, and the method comprises the steps: firstly inputting the known output active power limit of a to-be-solved network construction type converter; inputting a step disturbance amplitude, a damping coefficient initial value 0.1, a damping coefficient maximum value, a damping coefficient search number and an inertia time constant set by the to-be-solved grid-constructing converter; secondly, according to a closed-loop transfer function formula of output active power and grid-connected point angular frequency of the network construction type converter, obtaining an active output response function of the network construction type converter; and finally, calculating the damping ratio, response time and adjustment time of the active power output by the grid-forming converter, and obtaining a damping coefficient parameter range by combining the requirement of the national standard GB / T 38983.1-2020 on the active frequency modulation capability of the virtual synchronous machine. The method can be used as a support basis for the control parameter design of the network-constructing converter, the active support capability of the network-constructing converter is improved, and the safe and stable operation of a power system is ensured.

The invention discloses an intelligent self-adaptive injection flow regulation and control system for geological storage. The system comprises a sensor module, a data processing module, an execution mechanism module and a self-adaptive algorithm module, the sensor modules are distributed in an injection well and a surrounding monitoring well and are used for acquiring pressure, temperature and flow data in real time; the data processing module performs normalization processing on the monitoring data and extracts dynamic characteristics; the adaptive algorithm module integrates a multi-parameter coupling regulation and control model constructed by fuzzy PID and an LSTM neural network, predicts the trend of a seepage field and generates a regulation and control instruction; the execution mechanism module adjusts an electric control valve group and a variable-frequency injection pump according to instructions, so that the error between an actual injection curve and a target parameter curve is smaller than 5%. All the modules form a closed-loop control system through an industrial Internet of Things platform, the LSTM neural network updates weight parameters every 30 minutes, and a fuzzy PID controls an integral time constant to be automatically adjusted. The system is suitable for geological storage of CO2, accurate regulation and control of the injection flow can be achieved, and the leakage risk and the injection energy consumption are reduced.

The invention discloses a vibration test and state monitoring method and system for an in-operation high-voltage circuit breaker, and the method comprises the steps: carrying out the energy propagation time sequence test of a multi-measurement-point vibration signal, constructing an energy flow direction topological graph, and precisely positioning a vibration source region through energy ratio analysis and path backtracking; acquiring a response time constant by adopting an impact response attenuation test, and converting a vibration source into a fault space positioning coordinate through space grid division and rate matching; a frequency-space mapping relation is established based on a fault position, and vibration characteristics are comprehensively described through peak frequency time sequence tracking and nonlinear component identification such as frequency multiplication, modulation and transient state; performing dispersion analysis on the continuous action impact peak value to form an action consistency deviation, and fusing a nonlinear feature set to quantitatively evaluate the mechanical degradation degree; the grading test density is generated according to the degradation state, the time period test unit is determined, the state grading test benchmark is established to realize mechanical state grade judgment, and the equipment operation reliability and the monitoring efficiency are improved.

The invention relates to a frequency converter dynamic performance optimization control method, and belongs to the technical field of power electronics. The method comprises the steps that frequency converter operation and device characteristic signals and external working condition correlation signals are collected in real time and integrated into a multi-dimensional operation data set, an analysis model is built, and a mapping relation is preset; extracting transient characteristics of a device switch, calculating a dynamic impedance parameter based on a mapping relation, and matching a parameter self-tuning rule base to generate a current loop proportionality coefficient, an integral time constant and a modulation wave duty ratio correction; a rotating speed and current double-loop fusion framework is built, the weight of an outer loop is dynamically adjusted according to rotating speed deviation and load sudden change, an inner loop adopts an adaptive reaching law and disturbance compensation, and a cooperative control instruction is generated through inter-loop interaction; monitoring instruction execution data to form feedback, correcting a model mapping relation and optimizing control parameters. The dynamic response precision of the frequency converter under complex working conditions is improved, the anti-disturbance capability is enhanced, and meanwhile, the device operation loss and the manual debugging cost are reduced.

This numerical control device comprises a distance control unit, a filter unit, a determination unit, and a setting unit. The distance control unit controls the distance between a first object and a second object to be close to a target distance. The filter unit filters a signal indicating the distance. The determination unit determines, on the basis of the target distance, a time constant obtained from the relationship between the distance and an output signal from a distance sensor that measures the distance. The setting unit sets a time constant of the filter to the time constant determined by the determination unit.

The invention relates to the technical field of motor control, and discloses an induction motor rotor time constant adaptive control method, system and device, and the method comprises the steps: determining a rotor time constant estimation value based on the reactive power deviation of a model reference adaptive system; determining a rotor resistance estimation value according to the rotor time constant estimation value and a rotor inductance parameter value obtained in real time; performing low-pass filtering on the rotor resistance estimation value to generate a filtering value; updating a rotor time constant feed-forward value based on the rotor inductance parameter value and the filtering value; and based on the rotor time constant feedforward value, optimizing a convergence process of the rotor time constant estimation value so as to perform indirect vector control of the induction motor. The method has the beneficial effect that the convergence speed and robustness of adaptive identification of the rotor time constant are improved.

The invention relates to a high-voltage SF6 circuit breaker asymmetric short-circuit current breaking result prediction method, equipment and a medium. The method comprises the following steps: acquiring a plurality of groups of arc voltage and arc current test data obtained by performing a T100a test on a target circuit breaker under a first time constant; based on the test data, establishing a black box arc model, and fitting to obtain arc dissipation power and arc time constant corresponding to each group of test data through numerical solution and parameter optimization algorithms, thereby obtaining an on-off critical value; fitting is carried out in an arc breaking critical parameter fitting model, and values of a first parameter, a second parameter, a third parameter and a fourth parameter are determined; and obtaining a predicted value of an on-off value under the working condition through an arc on-off critical parameter fitting model, if the predicted value is greater than an on-off critical value, determining that on-off is successful, otherwise, determining that on-off is failed. Compared with the prior art, the method has the advantages of high accuracy, high practicability, simple process and the like.

The invention discloses a speed loop two-degree-of-freedom PI control method and device based on feedforward and a medium, and relates to the technical field of speed loop control methods.According to the method, on the premise that the bandwidth of an inner current loop is higher than that of a speed loop, a PI feedback steady state is adopted, and a disturbance observer is used for load disturbance estimation and compensation; feedforward forming is introduced to a given side, a'given-output 'closed loop is shaped into a first-order or critical damping second-order target model, and a disturbance observer time constant, a target bandwidth and a sampling period are systematically set. The device is composed of an error acquisition module, a PI feedback module, a disturbance observation module, a feed-forward forming module and an execution interface module. According to the scheme, under the condition that hardware is not changed, rapid low-overshoot tracking is achieved, the anti-interference performance is not weakened, parameters can be reused, and the method is suitable for servo scenes such as numerical control, robots and stabilized platforms.