59 results about "Physical Concepts" patented technology

The invention discloses a micro-grid short-term load forecasting method based on the EMD-KELM-EKF, and belongs to the technical field of intelligent power grids. The method includes the steps of firstly, preprocessing micro-grid history load data, enabling the preprocessed micro-grid history load data to serve as a training sample, and extracting the load attribute of the training sample; secondly, determining a combined forecasting model based on the EMD-KELM-EKF and parameter initial values of the combined forecasting model; thirdly, optimally selecting parameters of the combined forecasting model through a particle swarm optimization algorithm; fourthly, substituting a test sample into the combined forecasting model based on the EMD-KELM-EKF with determined parameters to obtain a forecasting result. The method is clear in physical concept and thought, and provides the theoretical foundation for micro-grid short-term load forecasting, and calculation is easy and convenient; according to the method, by means of the implementation pattern of combining offline parameter optimization with online forecasting, the forecasting result is good in stability, and optimal dispatching can be easily conducted on micro-grids.

The invention discloses a method for measuring parameters of a permanent magnet synchronous motor and belongs to the field of motor parameter measurement. The method includes utilizing the A phase no-load counter EMF (Electromotive Force) of a motor and the electric angular velocity of the motor to obtain a permanent magnet flux linkage, utilizing the wave form of the A phase no-load counter EMF and a position sensor to read the corresponding electric angular positions of the 90-degree angle and 0-degree angle of a motor rotor, changing the connection type of a stator winding, and utilizing the alternating voltage, current and frequency to respectively obtain corresponding direct-axis inductance and quadrature-axis inductance. The apparatus used in the method are conventional apparatus and the method has the advantages of clear physical concept, easy operation, high measurement accuracy and the like.

The invention discloses a magnetic core loss separation calculating method. The method includes the following steps: under the condition of the given magnetic flux density variable quantity, , forming a magnet loss construction separation equation set to separate magnetic hysteresis loss from vortex loss by using loss data of any two working points with different frequency under sinusoidal excitation, simulating corresponding relation of resistance rate of magnetic core materials and frequency of the magnetic core materials through a linear interpolation method, and gathering the additional vortex loss of the rest loss to a classical conduction vortex loss. The magnetic core loss separation calculating method has the advantages of being clear in physical concepts, simple in separation calculation process, capable of effectively separating loss components of the magnetic core without dependence on a special instrument, and being widely applied to simulation software to simulate size of loss of the magnetic core materials in power electronic application under different frequency and magnetic induction intensity.

The invention provides a method for distinguishing lightning stroke and non-lightning stroke faults of a transmission line. According to the characteristics of fault traveling wave current on a transmission line lead, the wave tail time of faults traveling wave current is compared with a threshold value to identify lightning stroke and non-lightning stroke faults. The method has a very clear physical concept and has good practicality.

The invention discloses a channel modeling method and parameter matching method based on non-uniform scatterer distribution, which belongs to the technical field of wireless communication. The invention based on the improved channel model realizes and introduces two physical concepts such as a scattering probability and a effective scatterer, comprehensively describes a propagation characteristic in various specific environments accurately and flexibly, conveniently estimates a mobile communication environment of a macro cell, a microcell and the like accurately and flexibly, and effectively improves accuracy of an electromagnetic signal wave arrival angle, a wave arrival time, a Doppler effect and other channel parameter. The invention based on the established channel model, according to a channel information of receiving end, according to the channel state reasonably distributes an antenna and power resource, thereby effectively reaching the maximum vaue of the channel in the condition of no-increase channel bandwidth, and improving the resource utilization efficiency of the channel.

The invention discloses a method for distinguishing the stability of a tunnel at different construction stages. According to the method, a new concept, namely a surrounding rock yield volume ratio, capable of reflecting the tunnel surrounding rock engineering mechanical characteristics and influence of tunnel excavation and supporting effects is provided, the mechanical characteristic, which is anexcavated tunnel deformation gradually developing process, namely a surrounding rock stress gradually releasing process, is utilized, the variation curve of the surrounding rock yield volume ratio along with a surrounding rock stress release rate after the tunnel excavation at a certain construction stage is established, and the stability of the tunnel at that construction stage can be determinedby utilizing the mutation characteristics of the curve. The method has the advantages of clear and simple physical concept, convenience in use, reliable result and the like, and is suitable for popularization and application in construction safety management of engineering under highway tunnels, railway tunnels, hydraulic tunnels, municipal tunnels and the like.

The invention discloses a structural extraction method and system of positional information based on a semantic position model. The method includes establishing a positional basic concept ontology, a positional physical concept ontology based on the semantic position model and filling ontology instance; classifying the positional basic concept ontology and the positional physical concept ontology to establish corresponding positional structure concept ontologies; automatically mapping the location structuring concept ontologies to generate rule classes, each rule class corresponds to one positional physical concept ontology and is inheriting and greedy; instantiating all the rule classes to generate rule objects, and to finally generate rule sets; classifying the rule sets, re-classifying them into a plurality of rule groups to form a rule retrieval dependency graph; further establishing a reverse retrival between the concept ontology and the rules of each rule group; matching positional descriptive graphs by using a rule matching algorithm to match and finish structuring extraction of positional information.

The invention provides an HVDC (high voltage direct current transmission) system wide area distributed and cooperative control method based on a convex polyhedron theory. The HVDC system wide area distributed and cooperative control method based on the convex polyhedron theory includes following steps: building an HVDC system model, and performing linear treatment on the HVDC system model; using a wide area distributed and cooperative controller to control the HVDC system model; confirming satisfaction conditions of stable running of a closed dynamitic linear output feedback control system; designing a wide area distributed and cooperative controller based on the convex polyhedron theory. The HVDC system wide area distributed and cooperative control method based on the convex polyhedron theory has the advantages of being clear in mathematical and physical concept, high in calculation speed, strong in adaptability and the like, not only is suitable for wide area damping coordinated control of an HVDC system, but also can be used in design of multiple FACTS coordination controllers and coordination control of other damping controllers, and has a wide application prospect.

The embodiment of the invention discloses a method and a device for judging the oscillation damping ratio polarity of a generator speed regulating system. Starting with an occurrence mechanism of a small disturbance fluctuation process of a generator set, the invention discloses a relation between the damping ratio of the generator speed regulating system and an important variable in the small disturbance process, thereby being capable of judging the oscillation damping ratio polarity of the generator speed regulating system quickly, simply and conveniently, not only having an intuitive physical concept, but also being easy to calculate in formula, and being convenient for visually judging whether the speed regulating system provides positive damping to suppress low-frequency oscillation or provides negative damping to intensify power oscillation in the low-frequency oscillating process.

The invention discloses a method for obtaining a proton single-particle effect cross section of a device. The method comprises a step of carrying out heavy ion single-particle effect experiment on thedevice to obtain heavy ion single-particle effect cross-section experimental data, a step of fitting the experimental data by using a Weibull function and obtaining a fitted heavy ion single-particleeffect cross-section function, a step of constructing a device structure including a plurality of metal wiring layers, calculating the nuclear reaction of protons with energy E and a material by using Monte Carlo particle transport simulation, generating secondary particle probability p(EP,L) with LET as L at a device silicon region, and further calculating an integral probability function P(EP,L), and a step of integrating a product of the heavy ion single-particle effect cross-section function and a proton integral probability function and calculating the proton single-particle effect crosssection of the device. According to the method, the evaluation of the ability of the device to resist the proton single particle can be achieved, and the method has the characteristics of clear physical concept and high accuracy of a data result.

The invention discloses a method for calculating magnetic core loss of a Boost converter. Under the condition of determining a change quantity of magnetic flux density when a duty ratio D is equal to 0.5, by analyzing a working principle of a Boost converter circuit, a relational expression among magnetic hysteresis loss, eddy current loss and the duty ratio is established, and a magnetic core loss change law of a magnetic core when the duty ratio of the Boost converter is changed is predicted. The method has the advantages that a physical concept is clear; a calculation process is simple; and the loss of a magnetic core material in an output inductor of the Boost converter under the condition of different duty ratios can be effectively predicted.

The invention discloses an assessment method and system for the voltage supporting capability of a multi-DC-feed AC power grid, and the method enables the voltage supporting capability of the multi-DC-feed AC power grid to be reflected by the capability of simultaneous increase of active power of an AC system for supporting a multi-DC power transmission line. Through the setting of an incidence matrix for the increase of a current constant value of the multi-DC power transmission line, the margin between the maximum value of the increase of DC power and a rated value is calculated, thereby forming quantitative indexes for the assessment of the voltage supporting capability of the multi-DC-feed AC power grid. The method and system are clear in physical concepts, is high in adaptability, and is good in prospects of popularization and application.

The invention discloses a low order circulation suppression method for modular multilevel converters. The method comprises the steps that according to capacitance voltage values udcui and udcli of a certain phase upper and lower bridge arm module collected in the k-1th and k-2 th sampling time, a sub-module capacitance voltage prediction value for the calculation of the k th time is obtained; estimated values of common and differential modulus components, as shown in the description, of the sub-module capacitance voltage of the phase are calculated, and an actual common mode current icm of the phase is calculated; a reference value of the common modulus current component of the phase, as shown in the description, is calculated, and a common modulus modulation ratio m'cm of the phace with the total DC voltage control capability is calculated; a common modulus modulation ratio of the phase m'cm_C with the low order circulation suppression capability sets the different value between the complimented common modulus modulation ratio m'cm_C and differential modulus modulation ratio mdm as the actual modulation signal of the upper bridge arm of the phase; the sum value between the complimented common modulus modulation ratio m'cm and the differential modulus modulation ratio mdm is set as the actual modulation signal of the lower bridge arm of the phase. The low order circulation suppression method for the modular multilevel converters achieves the suppression of broadband circulation ripple wave, the method is simple and convenient to implement, the physical concept is clear, and the engineering application value is high.

The invention discloses a non-inertial counter-gravity measurement device and an application method. A non-inertial counter-gravity technology belongs to the property that the motion of a kinetic system relative to a static system is called a convected motion in theoretical mechanics, and is characterized in that: the non-inertial counter-gravity technology is inapplicable to the Newton's law. In short, the nature of gravity is a force like all forces, and the gravity is applied to a certain specific mechanical system structure by a technical method to realize the force nature, and forms a system of concurrent forces with acting forces to apply work. The measurement device can measure counter-gravity values of a resultant force of the system of concurrent forces at each point in 90 degrees. The physical concept of the counter-gravity value is that: the counter-gravity value makes an object similarly weightless, namely, if the acting forces are unchanged, the gravity is increased, and on the contrary, if the gravity is unchanged, the acting forces are reduced. Therefore, energy saving and consumption reduction similarly in a weightlessness mode are realized.

The invention discloses a method for rapidly evaluating the maximum wind power permeability under consideration of a frequency accumulation effect. The method comprises the following steps that firstly, according to the polymerization of topological structure of a power grid, a generator and a speed regulator parameter, an average system frequency response model of a wind power grid-connected electric power system is established; a frequency safety stability margin index is calculated on the basis of the frequency accumulation effect; and the quantitative function relation between the wind power permeability level and the safety margin index is established by combining the frequency response characteristic and the safety margin index constraint, so that the frequency safety state and the maximum wind power permeability level of the wind power grid-connected electric power system can be quickly and effectively predicted. The frequency safety and stability margin index is provided by theinvention, the physical concept is clear, and the dynamic safety state of the system frequency can be objectively reflected, the frequency safety state and the maximum wind power permeability of thewind power grid-connected electric power system can be quickly and effectively predicted, and the method has important significance in guaranteeing safe and stable operation of the system.

The invention discloses a separation barrel sea surface floating oil recovery device. The device comprises a floating body sucking disc, a seawater floating oil pipe, a sucking pump, a seawater floating oil collection barrel, a seawater discharge valve, floating oil discharge valves, a floating oil collection barrel and the like, wherein one end of the seawater floating oil pipe is connected with the sucking disc, and the other end of the seawater floating oil pipe is connected with the sucking pump; the seawater floating oil collection barrel is provided with a first-stage floating oil discharge valve, a second-stage floating oil discharge valve and a third-stage floating oil discharge valve; the floating oil collection barrel is arranged below a floating oil discharge port; and the bottom of the seawater floating oil collection barrel is provided with the seawater discharge valve. Compared with the prior art, the device has a simple structure and certain popularization space, and is clear in physical concept, low in cost, obvious in seawater floating oil separation effect, high in floating oil purification degree, convenient to use and overhaul, energy-saving, environment-friendly, and suitable for separating and recovering sea surface floating oil.

The invention discloses a medium-and-long-term electricity market safety checking and model establishing method, device and equipment. The method comprises the steps of obtaining a load prediction deviation; obtaining a predicted completion rate deviation; establishing a target optimization function according to the obtained load prediction deviation and prediction completion rate deviation; constructing a constraint item; and establishing a medium-and-long-term electricity market safety check model according to the target optimization function and the constraint term. According to the schemeof the invention, since load prediction deviation is the most important factor causing transaction completion rate deviation, so the influence of the load prediction deviation is considered. The target optimization function is established according to the load prediction deviation and the prediction completion rate deviation, the medium-and-long-term power market safety check model is establishedin combination with the constraint term, safety check is performed based on the model, and the safety check effect can be improved. The method is clear in physical concept, is closely combined with the current security check and transaction execution business, and has a significant effect on improving the feasibility of medium and long term power market security check.

The invention provides a power transmission line wind-deviation fault intelligent identification method. A fractal theory is utilized to perform fault time traveling wave current waveform similarity comparison so that power transmission line wind-deviation fault intelligent identification is realized. The method comprises the following steps: power transmission line current online monitoring data are acquired, and fault time traveling wave current data are extracted; fractal dimension of the traveling wave current data at each fault time is calculated; and the fractal dimension is analyzed and an identification result is outputted. Compared with methods in the prior art, the method is intelligible in physical concept and clear in judgment thinking so that whether a traveling wave current signal is a signal of a lightning stroke power transmission line lightning wire and a tower pole can be effectively identified.

The invention provides a calculating method for a long-and-short pile combined support structure. When the long-and-short pile combined support structure is designed, for a local unit model which is located at the selected weakest and most dangerous section and contains N

piles, the soil pressure at the part above the pile bottoms of short support piles is jointly borne by long support piles and the short support piles, and the soil pressure at the part below the pile bottoms of the short support piles is completely borne by the long support piles independently; 2N

boundary conditions are formed by presuming that the bending moment and shearing force at the pile bottom of each pile are zero, N

boundary conditions are formed by presuming that the bending moment at the pile top of each pile is zero, N<p-1> boundary conditions are formed by presuming that the pile topes of all the piles are equal in displacement, one boundary condition is formed by presuming that top beams in the local unit model are in a balanced state, and then all the boundary conditions are combined to form 4N

boundary conditions; and a local unit model control equation set based on the elastic resistance method theory is solved through a shooting algorithm based on the Broyden method iteration, and thus the displacement, rotating angle, bending moment and shearing force of a pile body of each support pile are obtained. According to the calculating method, the concept of the local unit model is provided, and only the most dangerous area needs to be calculated; the design safety is achieved, and meanwhile, the spatial effect of the combined action of the long-and-short pile combined structure can be considered, so that the physical concept is clear, and calculation is simple; and the shooting algorithm based on the Broyden method iteration is not sensitive to the setting of an initial value, the convergence speed is high, and the stability is good.

The invention relates to a method for evaluating the reliability of information transmission of an active power distribution network by considering secondary equipment influence, and belongs to the technical field of the reliability evaluation of a power distribution network. The invention provides an analysis and calculation method for evaluating the reliability of the active power distribution network by considering the secondary equipment influence. The method comprises the following steps of acquiring a fault rate and a repair rate of a terminal acquisition device, an information transmission system and a control main station on the basis of the engineering practice of the active power distribution network, and obtaining the correct transmission probability of the information in the active power distribution network between the terminal acquisition device and the control main station; establishing an area connection matrix and a fault judging matrix, and classifying load points on the basis of the area connection matrix and the fault judging matrix; and finally evaluating the influence of a primary equipment fault in each area on the reliability of each load point, thereby obtaining the fault rate of the load point as well as the reliability index of annual power failure time. The calculation process is clear in physical concept, and the influence of secondary equipment on the reliability of the active power distribution network can be effectively and quantitatively evaluated.

The invention discloses a minimal zero-sequence component compensation control method for a three-phase bridge-type DVR in the technical field of control of the power system. The method adopts the technical scheme that the each-phase voltage phasor and the zero-sequence component of the output voltage of the DVR are determined; the load reference voltage locus circle and the each-phase limit offset voltage locus circle are established; the each-phase compensated load voltage locus phase range and the zero-sequence output voltage during the same-phase compensation are determined; and the minimum state of the zero-sequence component is searched from the same-phase compensating position through minute angular deflection, and the corresponding DVR each-phase output offset voltage is calculated, so that the minimum zero-sequence compensating control in the three-phase system including the zero-sequence component is realized. The invention has the characteristics of definite physical concept, clear thought and simple and convenient calculation and is suitable for the minimum zero-sequence compensating control of the bridge-type structure DVR.

The invention discloses an adjustable inertial spinning top and belongs to the spinning top technical field. The adjustable inertial spinning top comprises a spinning top rotation shaft, a spinning top frame which is slidingly fixed on the spinning top rotation shaft through a sliding structure and a plurality of balancing rings with different diameters, wherein the balancing rings are movably arranged on the spinning top frame. According to the adjustable inertial spinning top of the invention, the balancing rings with different diameters are arranged on the spinning top frame, so that the centroid of the spinning top frame can be adjusted through the balancing rings, and the position of the spinning top frame on the spinning top rotation shaft can be adjusted through the sliding structure, and therefore, the centroid of the whole spinning top can realize a plurality kinds of rotation inertial, and better rotation ability and attack ability can be realized; the spinning top has a plurality of physical characteristics, so that a user only need to by one such spinning top of the invention, and the economic burden of the user can be decreased; and kids can comprehend physical concepts such as mass and inertia in inertial adjustment, and can have very enjoyable and educational experiences, and the growth of knowledge can be realized in playing.

The invention discloses a method for calculating magnetic core loss of a Flyback converter. Under the condition of determining a magnetic flux density change quantity when a duty ratio D is equal to 0.5, a working principle of a circuit of the Flyback converter is analyzed, and a relationship among magnetic hysteresis loss, eddy current loss and the duty ratio is established, so that a magnetic core loss change law of a magnetic core during change of the duty ratio of the Flyback converter is predicted. The method is clear in physical concept and simple in calculation process, and can effectively predict loss values of a magnetic core material in an output inductor of the Flyback converter under the condition of different duty ratios.

The invention discloses a pinhole diffraction analysis method based on the waveguide effect in a point diffraction interferometer and solves a problem of difficulty in realizing both acceleration of the calculation speed of the diffraction light field and accurate analysis on interaction of the light fields of a pinhole wall and in the hole. The method comprises steps that a pinhole is taken as the cylindrical waveguide to handle the conduction effect for the light field, specific steps are as follows, firstly, field distribution of a guided mode matching the incident light field at a rear endsurface of the pinhole is acquired by solving Maxwell's equations, secondly, near-far field transform based on the field equivalence principle is utilized to acquire the diffraction light field at afinite distance from the pinhole from the light field at the rear end surface of the pinhole, and lastly, properties of the diffraction wavefront are acquired by analyzing non-radial components of thediffraction light field. The method is advantaged in that physical concepts and theoretical support are provided by pinhole diffraction analysis based on the electromagnetic field numerical method, and the method is of great significance to accurate analysis the pinhole diffraction wavefront.