18 results about "Mixed potential" patented technology

The invention discloses an AC / DC hybrid micro-grid large signal stability improving method and device based on a super capacitor integral droop control strategy and a medium, and belongs to the technical field of power electronic technology and AC / DC hybrid micro-grid system.The AC / DC hybrid micro-grid large signal stability improving method comprises the steps that a super capacitor is connected to a DC bus in parallel, and the super capacitor and a VSC work cooperatively; the supercapacitor employs integral droop control to manage the discharge rate, and the VSC employs voltage-current droop control. And establishing a large-signal nonlinear model of the system and performing stability analysis by using a mixed potential function theory. According to the invention, a voltage source converter adopting traditional U-I droop control and a super capacitor adopting integral droop control work cooperatively: when large disturbances such as constant power load sudden change occur, SC controls a high-frequency component required by instantaneous compensation power through ID by virtue of a quick response characteristic of the SC; and the VSC responds to smooth change of load power and provides low-frequency power support through U-I droop control.

The invention is suitable for the field of gas sensor detection, and provides a mixed potential type ammonia gas sensor and a preparation method thereof. The mixed potential type ammonia gas sensor comprises a layered nickel silicate sensitive electrode, a reference electrode and a solid electrolyte, the layered nickel silicate sensitive electrode and the reference electrode are positioned on the surface of the solid electrolyte; the layered nickel silicate sensitive electrode is prepared from three kinds of layered nickel silicate electrode slurry with different morphologies. According to the invention, the layered nickel silicate is used as the sensitive electrode, so that the response value to ammonia gas is obviously improved at room temperature; compared with an existing most advanced mixed potential type ammonia gas sensor, the high-temperature mixed potential type ammonia gas sensor has the advantage that the low-concentration response to ammonia gas can be remarkably improved at room temperature compared with other high-temperature mixed potential type ammonia gas sensors.

The invention discloses a large signal stability analysis method for a dual-power-supply cascaded power electronic transformer, which relates to the technical field of power electronics and comprises the following steps: establishing a state space averaging model of the dual-power-supply cascaded power electronic transformer; according to the state space averaging model of the dual-power-supply cascaded power electronic transformer, constructing a mixed potential function of the dual-power-supply cascaded power electronic transformer; and performing analysis based on the mixed potential function of the dual-power-supply cascaded power electronic transformer in combination with a large signal stability criterion to obtain a large signal stability analysis result of the dual-power-supply cascaded power electronic transformer. According to the method, the stability domain of the dual-power-supply cascaded power electronic transformer in large disturbance scenes such as voltage sag and power abrupt change can be analyzed, and the influence of alternating current system parameters, power electronic transformer hardware parameters and controller parameters on the stability domain can be analyzed accordingly.

The present invention discloses a method for testing the surface roughness of silicon-based solar cells based on molecular dynamics simulation. The method uses the "deposit" command in the Lammps software to deposit SiH3 molecules onto a smooth crystalline silicon substrate. The "deposit" command in the molecular dynamics simulation serves as a loading tool. According to Newton's second law, the velocities of the atoms that make up the molecules change after deposition, and the forces between the atoms cause the SiH3 molecules to grow on the crystalline silicon, resulting in the growth of a hydrogenated amorphous silicon film on the crystalline silicon. A mixed potential function is used to describe the atomic-to-atomic interactions between the crystalline silicon and the SiH3 molecules. This method, based on the open-source software Lammps and the visualization tool Ovito, combines the roughness formula with the visualization results to calculate the surface roughness of hydrogenated amorphous silicon films grown on crystalline silicon, providing theoretical guidance for the conditions required for practical film production.

The present invention relates to a method for measuring the coefficient of restitution of nano-sphere particle collision based on molecular dynamics, comprising: establishing two nano-sphere Al2O3 particle models using OVITO software; placing a nitrogen molecule model, an oxygen molecule model, and the two particle models in a simulation box to form a simulation object system, and importing the LAMMPS software; using comb3 and lj / cut mixed potential; setting simulation parameters, performing molecular dynamics simulation, obtaining parameter data during the movement of the particle model, and observing the deformation of the particle model during the collision process; post-processing the parameter data to obtain a force-displacement curve of the particle model, judging the collision occurrence and end time of the particle model, and determining the collision velocity of the particle model and the separation velocity during rebound, and calculating the collision coefficient of restitution of the particle model based on the velocity changes before and after the collision. The present invention overcomes the limitations of traditional methods and improves measurement accuracy.

A multi-electrode sensor array includes a substrate and n test couples on the substrate, wherein n is an integer of 2 or greater. Each test couple includes a pseudo-reference electrode and a sensing electrode including a material capable of oxidizing or reducing a gas of interest. A solid electrolyte layer that is common to and continuous over the n test couples may cover at least a portion of each pseudo-reference electrode and at least a portion of each sensing electrode. At least one of the n test couples may include an initial test couple and one or more duplicates thereof connected in electrical series, and a mixed potential may be measured across the electrical series. When multiple electrodes having different electrocatalytic activities are combined in the array of n test couples, mixed potential data from the array may be mathematically processed to accurately measure gas concentrations in a mixed-gas environment. The electrodes may be designed and arranged to increase the selectivity and sensitivity of the multi-electrode sensor array.

The invention provides a grid-following type grid-connected converter low voltage ride-through stability control method under a weak power grid condition, and belongs to the technical field of grid-connected converter low voltage ride-through stability control. A grid-following type grid-connected converter system equivalent model under a weak power grid is established based on a grid-following type three-phase two-level grid-connected converter system topology; a transient stability criterion of the following grid type grid-connected converter system under the weak power grid is obtained by combining a mixed potential function theory; and according to a transient stability criterion, an active current and reactive current reference value calculation formula capable of transmitting the maximum active power to the power grid on the premise of meeting stability is obtained, and comparison verification is carried out by adopting a traditional low voltage ride through control method, so that stable grid connection of the new energy power generation unit during the voltage drop period of the power grid is ensured.

The present disclosure belongs to the technical field of hydrogen production by water electrolysis, and provides a hydrogen evolution electrode damage quantification and positioning method based on a reverse voltage plateau period, wherein the quantification method comprises: determining an electrolytic tank shutdown event and synchronously collecting electrolytic tank parameter data; based on the electrolytic tank parameter data, extracting single-cell characteristic parameters of a mixed potential plateau period; constructing an electrode damage equivalent model, and inputting the characteristic parameters to calculate single-cell damage equivalents. The present disclosure proposes and establishes a quantitative mapping relationship between the "reverse voltage plateau duration T" and the "electrode corrosion damage amount", and realizes online, quantitative and spatial positioning evaluation of internal damage of an alkaline electrolytic tank based on the same.

This invention provides a method for simulating the irradiation response of Ti-Al-Nb-Zr-Mo pentagonal alloys based on a hybrid potential function, belonging to the technical field of potential function development for irradiation damage simulation of metallic materials. This method aims to solve the problems of existing potential functions failing to accurately describe high-energy collisions and the lack of smoothness at the connection points of hybrid potential functions. The solution includes: obtaining pure metal parameters to generate an initial embedded atom-based potential function; introducing a Ziegler-Bissack-Littmark potential function to describe short-range interactions; using spline functions to smoothly connect the two potential functions, ensuring the continuity of function values ​​and first derivatives at the connection points by solving boundary conditions; and finally generating a hybrid potential function file compatible with molecular dynamics software. This invention, by smoothly connecting short-range and medium-to-long-range potential functions, can accurately describe the full range of atomic interactions, avoid energy jumps in the simulation, and improve the accuracy of irradiation damage simulation.

The invention discloses an MMC virtual resistance regulation and control method, system and device and a medium, and the method comprises the steps: setting an operation environment of a modular multilevel converter (MMC) in a mountain area power distribution network, carrying out the equivalent combination of the electrical parameters of an AC side and a bridge arm, and building an average simplified model suitable for large disturbance analysis; analyzing an energy relationship between non-energy storage and energy storage elements by applying a mixed potential function theory, and constructing a large interference stability criterion; a virtual resistance variable is introduced to a direct current side, equivalent power consumption is converted into a d-axis active current adjusting variable according to an alternating current and direct current side power balance relation, an adjusted current reference value is generated, and a stable control scheme is formed; the virtual resistance is incorporated into stability criteria, boundary constraints meeting stability conditions are deduced in combination with typical disturbance (such as voltage drop and load abrupt change) characteristics of a mountainous area, and the value range and the setting value of the virtual resistance are determined. According to the invention, the transient stability and the power supply reliability of the MMC in the weak mountainous area power distribution network are obviously improved.

The application discloses a Van der Waals heterostructure potential field simulation method and device, and belongs to the technical field of quantum and molecular simulation. The method comprises the following steps: obtaining a first data set and a first parameter set corresponding to the first data set; training an MLP based on the first data set and the first parameter set, wherein the MLP is used for simulating the in-layer potential energy of the Van der Waals heterostructure; obtaining a second data set and a second parameter set corresponding to the second data set; fitting an anisotropic interlayer potential energy function ILP based on the second data set and the second parameter set, wherein the ILP is used for simulating the interlayer potential energy of the Van der Waals heterostructure; fitting the ILP based on the many-body effect to obtain a transition state ILP; and obtaining a first function based on the MLP and the transition state ILP, wherein the first function is used for simulating the transition state mixed potential energy of the in-layer-to-interlayer interaction of the Van der Waals heterostructure. The method can realize the simulation of the mixed force field of the Van der Waals interface while taking into account the calculation accuracy and efficiency.

The application relates to the technical field of steel metallurgy, in particular to a molecular dynamics analysis method for iron-based melt structure sensitivity and viscosity fluctuation under sulfur content disturbance, which comprises the following steps: constructing an Fe-C-Ti-S four-component iron-based melt atomic model; constructing a full-atomic cubic supercell model with a total number of atoms not less than 16000; setting the atomic mass as 55.845 g / mol, 12.011 g / mol, 47.867 g / mol and 32.065 g / mol respectively for Fe, C, Ti and S atoms; establishing a mixed potential function; simulating the Fe-C-Ti-S iron-based melt through molecular dynamics; calculating melt structure parameters; and calculating melt viscosity; the application can accurately describe the multi-body interaction and structure evolution characteristics among the Fe, C, Ti and S four-component elements, and realizes reliable simulation and prediction of the melt viscosity.

The application relates to the technical field of steel metallurgy, in particular to a molecular dynamics analysis method for Mn-regulated short-range ordered structure and viscosity response of an iron-based melt, which is used in a system with C content of 4.4wt%-4.8wt%, Ti content of 0.05wt%-0.2wt% and Mn content of 0.1wt%-0.5wt%, and comprises the following steps: constructing an Fe-C-Ti-Mn quaternary iron-based melt atomic model, establishing a mixed potential function, simulating the Fe-C-Ti-Mn iron-based melt through molecular dynamics, calculating melt structure parameters, and calculating melt viscosity; the application establishes a mixed potential function system suitable for the Fe-C-Ti-Mn quaternary iron-based melt, realizes high-precision modeling of a multi-component complex melt system through coupling and parameter optimization of the mixed potential function, systematically analyzes the influence law of Mn content change on the short-range ordered structure of the melt, and establishes a quantitative relationship between the Mn content and microstructure evolution.

This invention relates to the field of iron and steel metallurgy, and more particularly to a molecular dynamics modeling method for predicting the viscosity of blast furnace hot metal, specifically for blast furnace hot metal composition systems with a C content of 4wt%–5wt%, a Ti content of 0.01wt%–0.2wt%, and a Si content of 0.01wt%–0.5wt%. The method includes constructing a Fe-C-Ti-Si quaternary iron-based melt atomic model, using a hybrid / overlay mixing potential function to describe the interaction forces of all atoms within the system, performing molecular dynamics simulations of the Fe-C-Ti-Si iron-based melt, analyzing the microstructure characteristics of the obtained Fe-C-Ti-Si iron-based melt using molecular dynamics simulations, and calculating the melt viscosity. This invention can accurately describe the many-body interactions and structural evolution characteristics among the quaternary components Fe, C, Ti, and Si, achieving reliable simulation and prediction of melt viscosity.

The present disclosure relates to a kind of AC-DC hybrid micro-grid system stability determination method and device.Wherein, the method includes: establishing the equivalent model of the AC-DC hybrid micro-grid system under synchronous rotation dq coordinate system;Based on mixed potential function theory, generate the nonlinear model of the AC-DC hybrid micro-grid system;The steady-state operating point of the AC-DC hybrid micro-grid system is generated, and the steady-state operating point is generated according to the large signal stability criterion of the AC-DC hybrid micro-grid system;The large signal stability criterion is limited to the amplitude processing based on the preset reference current limiting value, and the stability determination of the AC-DC hybrid micro-grid system is completed based on the large signal stability criterion containing current limiting amplitude.The reference current limiting value of the converter current inner loop is limited in the present disclosure, and the large signal stability criterion is optimized, so that the accuracy and practicability of stability criterion are further improved.

The present invention relates to the technical field of direct current (DC) microgrid systems, and in particular to a method for analyzing the stability of a DC microgrid system based on an SOFC. Specifically, the method comprises the following steps: establishing a DC microgrid equivalent model based on the DC microgrid system; applying the mixed potential function theory based on the DC microgrid equivalent model to establish a mixed potential function of the system, then converting the mixed potential function into a unified expression of the mixed potential function, and finally deriving a system stability condition based on the third stability theorem; constructing a large-disturbance stability criterion function of the DC microgrid system based on the system stability condition and a control loop expression obtained by adopting a double-closed-loop control strategy for an SOFC converter and a lithium battery pack converter; and performing a stability analysis on the DC microgrid system based on the large-disturbance stability criterion function of the DC microgrid system. Through the above steps, the stability boundary of a large load disturbance can be calculated, thereby accurately and effectively performing a stability analysis on the DC microgrid system.

The application provides a DC micro-grid large signal stability boundary analysis method and system based on an equivalent remodeling circuit, comprising the following steps: S1: constructing a controller equivalent circuit based on a DC micro-grid control strategy; wherein the controller equivalent circuit comprises an inertia loop equivalent circuit, a voltage loop equivalent circuit and a current loop equivalent circuit; S2: constructing an equivalent circuit model of the DC micro-grid based on the constructed controller equivalent circuit; constructing a global mixed potential function of the system based on the constructed system equivalent circuit model; and S3: performing DC micro-grid large signal stability analysis based on the constructed global mixed potential function.

The invention relates to a reaction force field construction method, system and equipment for molecular dynamics simulation, belongs to the technical field of computational chemistry and material simulation, and solves the problems that in the prior art, a reaction force field construction method is insufficient in physical precision when describing short-range strong repulsion among atoms; and the efficiency is low when parameterization is carried out on a high-precision physical model. Comprising the steps of obtaining a first principle potential energy data set in a preset atom short distance range based on a target multi-body atom group; wherein elements in the first principle potential energy data set are distance vectors and multi-body interaction potential energy corresponding to the distance vectors; training a selected machine learning model on the basis of the first principle potential energy data set to obtain a potential energy agent model, and then obtaining an optimal short-range potential function by adopting Bayesian optimization on the basis of a selected potential function; and based on the optimal short-range potential function and the potential function of the reference reaction force field, a mixed potential function of the target multi-body atomic group is obtained, and construction of the reaction force field is completed.