Patents
Literature
Patsnap Eureka AI that helps you search prior art, draft patents, and assess FTO risks, powered by patent and scientific literature data.

828 results about "Voltage vector" patented technology

Method and system for cooperatively suppressing common-mode voltage and current harmonics of coupled three-level inverter

The present invention provides a method for cooperatively suppressing a common-mode voltage and current harmonics of coupled three-level inverters, comprising: based on amplitude and phase angle of reference voltage vector, determining sector and region in which the reference voltage vector is located; selecting four basic voltage vectors with low common-mode voltage amplitudes to synthesize the reference voltage vector; writing volt-second balance equation based on selected basic voltage vectors, and calculating duty cycles thereof; and based on sector and region in which reference voltage vector is located, set value of voltage difference across capacitors on direct current side, and actual value of voltage difference across capacitors on direct current side, (1) updating duty cycles of basic voltage vectors, to realize separate control of capacitor voltage; and (2) designing and converting switching sequence into PWM drive signal of power switch, to control the coupled three-level inverter to operate.
Owner:SHANDONG JIANZHU UNIV

Frequency conversion vector control method of digital energy-saving pump station

The invention discloses a frequency conversion vector control method for a digital energy-saving pump station, which belongs to the technical field of vector control and comprises the following steps: constructing a coupling vector model, simulating the running states of a pump unit under different working conditions through a virtual test signal, and automatically correcting the coupling vector model; operating data of a pump set are collected in real time, an operating situation feature set is constructed, predictive vector control is carried out, an optimal voltage vector sequence is generated, and meanwhile load fluctuation of a pipe network is predicted; demand pre-judgment is carried out on the starting and stopping time and the action amplitude of the anti-backflow device, a bidirectional disturbance suppression mechanism is constructed, current vector parameters are pre-adjusted, and calculus correction is carried out based on deviation judgment; when multiple pumps operate in parallel, the instantaneous operation efficiency point of the pump set is calculated in real time, the efficiency change trend is predicted, a load distribution scheme is generated, the comprehensive energy efficiency is evaluated, energy efficiency self-optimization is carried out, the comprehensive energy efficiency of the system is improved, and control experience reuse is achieved.
Owner:SHANGHAI PANDA MACHINEGRP CO LTD

Parallel three-level converter model prediction control method and system

The invention relates to the technical field of parallel three-level converter control, and provides a parallel three-level converter model prediction control method and system, and the method comprises the steps: enabling a parallel three-level converter to be modeled as a series connection of an equivalent voltage source and an equivalent filter inductor according to the Thevenin theorem, enabling the parallel three-level converter to be equivalent to a five-level converter, and enabling the parallel three-level converter to be connected in parallel; a three-layer optimization control strategy is adopted; in the first layer, a candidate vector closest to a reference voltage vector is selected as an optimal five-level basic vector so as to track a parallel total output current; in the second layer, a redundant five-level voltage vector is selected to balance the neutral-point voltage; and in the third layer, selecting the candidate switching state which enables the circulating current suppression value function to be the minimum as the optimal redundant three-level switching state so as to suppress the circulating current. The method can effectively reduce output current harmonics under low switching frequency, and balance of neutral-point voltage and effective suppression of circulating current are realized to ensure safe and stable operation of a parallel converter system.
Owner:SHANDONG UNIV

Newton iteration method vector optimization-based three-level ANPC converter model prediction control method and device

The invention discloses a three-level ANPC converter model prediction control method and device based on Newton iteration method vector optimization, and belongs to the technical field of converter control, and the method comprises the steps: building a mathematical model of a three-level ANPC converter under a three-phase static coordinate system based on the Kirchhoff theorem; performing forward Euler discretization on the mathematical model of the three-level ANPC converter to obtain a current prediction equation model; establishing a cost function according to the control target; performing online search on the optimal voltage vector according to a cost function; voltage vector synthesis is carried out, voltage vectors selected when the optimal voltage vector falls in 36 different small sectors, a voltage vector action sequence and action time distribution are obtained through calculation, and then the action time of a pair of redundant positive and negative small vectors in the voltage vectors is adjusted to carry out neutral point potential balance control. According to the invention, rapid optimal voltage vector search and three-level ANPC converter output current and neutral point potential control are realized.
Owner:INST OF ELECTRICAL ENG CHINESE ACAD OF SCI

A method for active harmonic suppression and optimization of water electrolysis hydrogen production rectifier transformer

The application discloses a kind of water electrolysis hydrogen production rectifier transformer harmonic active inhibition optimization method, comprising the following steps: constructing rectifier circuit, rectifier circuit includes switch tube, the voltage vector and zero vector of switch tube output are combined, and combined output voltage vector is obtained;The harmonic amplitude is obtained by processing combined output voltage vector, Levy tangent flight strategy and confidence domain variation strategy are introduced in black-winged kite optimization algorithm to construct improved dynamic search algorithm, the total harmonic distortion is obtained by iterative calculation of harmonic amplitude by improved dynamic search algorithm, i.e. optimal switch tube combination, the switch tube of rectifier circuit is adjusted by optimal switch tube combination, and the total harmonic distortion of rectifier circuit is reduced.The optimal switch tube combination of rectifier circuit is iteratively calculated by improved dynamic search algorithm in the application, effectively reduces resource consumption, and processing speed is accelerated, and the efficiency and accuracy of electrolytic water hydrogen production rectifier are improved.
Owner:江西变压器科技股份有限公司 +2

Power distribution network fault section rapid calibration method based on feeder terminal

The invention provides a power distribution network fault section rapid calibration method based on a feeder terminal. According to the method, power distribution network line electrical quantity and distributed power supply output information are collected in real time through a feeder terminal and preprocessed, then fault transient signals are processed through complete set empirical mode decomposition of mean value self-adaptive noise, and intrinsic mode components are obtained to judge fault types. Thirdly, fault section preliminary positioning is carried out, and an approximate area is determined according to a positive sequence voltage vector for a symmetric short-circuit fault, a negative sequence voltage vector for an asymmetric short-circuit fault and a zero sequence current amplitude for a single-phase earth fault; then accurate calibration is carried out, a single-phase earth fault is judged through a filter and correlation coefficients, and short circuit and broken line faults are calibrated through a model or an intelligent algorithm in combination with line topology and electrical parameters. And finally, establishing a target function containing a penalty term, converting the target function into a Markov decision process, solving through an approximate dynamic programming algorithm, realizing rapid and accurate calibration of a fault section, and improving the power supply reliability of the power distribution network.
Owner:HEBI POWER SUPPLY OF HENAN ELECTRIC POWERCORP

Direct current brushless motor control method and system based on current prediction

The invention relates to the technical field of motor control, discloses a direct current brushless motor control method and system based on current prediction, and aims to solve the problems of large torque ripple, low efficiency and poor stability caused by current loop lag in the prior art. The method comprises the following steps: acquiring a motor operation state signal in real time; determining a sector and an electrical angular velocity based on the rotor position and the rotational speed; inputting related parameters into the mixed current prediction model to obtain a three-phase current prediction value of the next period; a prediction error is calculated in combination with a current instruction, and an optimal voltage vector enabling a cost function to be minimum is solved through a model prediction control algorithm; and finally, a space vector pulse width modulation signal is generated to drive an inverter. According to the method, advanced control is realized by fusing a physical model and a data-driven prediction mechanism, the torque ripple is remarkably reduced, and the energy efficiency and robustness are improved.
Owner:LOUDI CHUANGWEIDA ELECTRICAL APPLIANCE CO LTD

Modularized multi-level converter multi-objective optimization method, system and device based on model predictive control and space vector modulation and medium

The invention is suitable for the technical field of flexible power distribution of a power system, and discloses a modular multilevel converter multi-objective optimization method, system and device based on model predictive control and space vector modulation, and a medium. Obtaining an output current reference value and a circulating current reference value; obtaining a reference voltage vector based on the output voltage reference value, and screening out a plurality of groups of redundant voltage vector sequences through a space vector diagram; performing performance evaluation through rolling optimization by combining each redundant voltage vector sequence with a multi-target cost function to obtain an optimal voltage vector sequence; and on the basis of the optimal voltage vector sequence and the corresponding duty ratio, a switching signal for driving each sub-module switching device of the MMC is generated, and multi-target cooperative control is realized. The three targets of reference output current tracking, circulating current suppression and sub-module capacitor voltage balance are met, and the dynamic response capability, efficiency and reliability of MMC system operation are comprehensively improved.
Owner:GUIZHOU POWER GRID CO LTD

Field weakening method of permanent magnet synchronous motor finite control set model predictive control system based on expected fundamental wave voltage closed loop

The invention discloses a flux weakening method of a permanent magnet synchronous motor finite control set model prediction control system based on an expected fundamental wave voltage closed loop, and belongs to the technical field of permanent magnet synchronous motor speed regulation control. According to the method, the problems of voltage saturation and poor robustness of a finite control set model prediction control system in a weak magnetic region are solved. According to the method, one-step delay compensation is carried out on the stator current, the stator current predicted value predicted through delay compensation is substituted into the voltage vector model under current vector dead beat control, and the compensated voltage vector reference value can be calculated. And an expected fundamental wave voltage vector is calculated based on the compensated voltage vector reference value, and finally the expected fundamental wave voltage vector is used as feedback of closed-loop flux-weakening control, so that maximum voltage control can be realized, and voltage saturation of a flux-weakening area is avoided. The method provided by the invention has better current dynamic performance, faster acceleration time and better robustness. The method can be applied to field weakening control of the permanent magnet synchronous motor.
Owner:NORTH CHINA ELECTRIC POWER UNIV

Coordinated optimization method and system of distributed power flow controller, and medium

The invention relates to the technical field of flexible power transmission of a power system, in particular to a coordinated optimization method and system of a distributed power flow controller and a medium, and the method comprises the steps: building a layered equivalent coupling model of the distributed power flow controller; taking minimization of the total loss of the flexible power transmission system as an optimization target, and performing global optimization on a parallel side output voltage vector and a series side injection voltage vector of the distributed power flow controller by using a layered equivalent coupling model to obtain an optimal coordinated optimization control strategy; obtaining a target control parameter in a target control mode according to the optimal coordination optimization control strategy; and according to the target control parameter and the real-time voltage and current data of the power transmission line, calculating a voltage compensation amount needing to be injected into the flexible power transmission system, and according to the voltage compensation amount, carrying out coordinated optimization control on the power flow of the power transmission line. According to the method, the parallel side and the series side of the distributed power flow controller are coordinated and optimized by establishing the layered equivalent coupling model, so that the voltage stability and power flow equilibrium distribution of the flexible power transmission system are effectively improved.
Owner:STATE GRID ZHEJIANG ELECTRIC POWER CO LTD

Permanent magnet motor model prediction control method and system based on triangular discrete space

The invention discloses a permanent magnet motor model prediction control method and system based on a triangular discrete space, and the method proposes a voltage vector discretization strategy based on a regular triangle, generates as many as 6 * 4 < n-1 > virtual voltage vectors through n times of iterative segmentation, and carries out the current prediction at a next moment through the virtual voltage vectors. And finally, screening out an optimal voltage vector by taking the minimum cost function value as a target, and using the optimal voltage vector for motor control. Besides, on the basis of virtual voltage vectors constructed by relying on midpoints of a regular triangle, under the enlightenment of exploring a specific geometrical relationship between the virtual voltage vector constructed in each layer of iterative segmentation process and the optimal voltage vector, efficient optimal voltage vector search is realized, the number of voltage vectors for online evaluation is effectively reduced, and the efficiency of online evaluation is improved. Therefore, the calculation burden is greatly reduced. According to the technical scheme, accurate control over the permanent magnet motor can be ensured, current harmonics of the motor can be effectively reduced, and thrust fluctuation is reduced.
Owner:HUNAN UNIV OF SCI & TECH

Phase delay error suppression method for midpoint current sensor of T-type three-level inverter

The invention provides a phase delay error suppression method for a midpoint current sensor of a T-type three-level inverter, and the method comprises the steps: determining a sector and a sub-region where a target voltage vector is located according to the input target voltage vector, selecting a basic voltage vector for synthesis according to the sub-region where the target voltage vector is located, calculating the action time of the voltage vector, and calculating the phase delay error of the midpoint current sensor of the T-type three-level inverter. The switching time of the seven-segment switch is determined, so that a seven-segment PWM switching signal is generated; judging whether the target voltage vector is located in an unobservable area according to the action time of the basic voltage vector; if yes, maintaining the original seven-segment PWM switching signal to send waves; otherwise, adjusting the seven-segment PWM switching signal, and compensating the observable voltage vector which does not meet the minimum sampling time by shifting the PWM signal to obtain a plurality of stable current sampling windows; and phase delay error compensation of the reconstructed three-phase current is realized according to the relationship between the sampling currents. According to the method, the distortion of the reconstruction current is improved, so that the precision of the three-phase reconstruction current is effectively improved.
Owner:ZHENGZHOU UNIVERSITY OF LIGHT INDUSTRY

Double-fan air conditioner and control method for single inverter and double motors of double-fan air conditioner

The invention discloses a double-fan air conditioner and a single-inverter and double-motor control method thereof. The control method comprises the steps that three-phase currents of a master motor and a slave motor which are the same in type and connected to the same inverter are collected, Park conversion is conducted to obtain d-axis components and q-axis components, and the observation angular frequency of the master motor is obtained through a position observer; calculating error angles of the master motor and the slave motor, controlling errors of the error angles through feedback, outputting a product of a motor speed difference reference value and the error angles, and obtaining a d-axis component compensation value idcomp through PI control; inputting a main motor angular frequency reference value in a speed control loop, outputting d-axis and q-axis component reference values of the current of the main motor, and compensating the d-axis component reference value of the current of the main motor with idcomp to obtain a final d-axis component reference value of the current of the main motor; and inputting the q-axis component reference value and the q-axis component reference value into a current control loop, generating a duty ratio signal of pulse width modulation, and controlling a master motor and a slave motor to rotate a voltage vector. According to the invention, through d-axis current injection compensation, system stability is realized.
Owner:GREE ELECTRIC APPLIANCE INC OF ZHUHAI

Electrical impedance imaging method and device based on hybrid excitation and program product

The invention relates to the field of intelligent medical treatment, in particular to an electrical impedance imaging method and device based on mixed excitation and a program product. Comprising the steps that an initial current vector and an initial boundary voltage vector of mixed excitation are obtained, the mixed excitation comprises L kinds of excitation, and L is a natural number larger than 1; performing weighted fusion on the L excitation initial current vectors to obtain a mixed excitation current vector, and performing weighted fusion on the L excitation initial boundary voltages to obtain a mixed excitation voltage; performing electrical impedance imaging optimization function calculation based on the mixed excitation current vector and the mixed excitation voltage to obtain conductivity change; the optimization function is used for carrying out regularization calculation on regional potential distribution and conductivity variation based on the mixed excitation current vector and the mixed excitation voltage; an electrical impedance distribution image is generated based on the conductivity change. According to the invention, the resolution of EIT imaging is improved, and the method has good clinical value.
Owner:FOURTH MILITARY MEDICAL UNIVERSITY

Control method and device of permanent magnet synchronous motor, electronic equipment and storage medium

The invention provides a permanent magnet synchronous motor control method and device, electronic equipment and a storage medium. The method comprises the following steps: acquiring a sampling rotor electrical angular velocity of the permanent magnet synchronous motor, and determining a first shaft current instruction based on the sampling rotor electrical angular velocity; determining a reference voltage vector according to the first axis current instruction and a preset second axis current instruction; synthesizing a reference voltage vector by using the first preset number of non-zero vectors and the second preset number of zero vectors; determining a candidate voltage vector set by adjusting the number of voltage vectors acting in the control period and the acting time of each voltage vector; constructing a cost function based on the current error, the current harmonic and the switching frequency, and determining an optimal voltage vector combination and action time from the candidate voltage vector set according to the cost function; and determining a driving signal of each switching tube of the inverter based on the optimal voltage vector combination and the action time, and controlling the permanent magnet synchronous motor based on the driving signals.
Owner:NORTH CHINA ELECTRIC POWER UNIV +2

Three-level SNPC inverter model-free strong-robustness predictive control method and system

The invention relates to the field of three-level inverters, and particularly discloses a model-free strong-robustness predictive control method and system for a three-level SNPC inverter, and the method comprises the steps: carrying out the real-time sampling and coordinate transformation of the inverter, and obtaining the current and voltage components under a two-phase static coordinate system; establishing a hyper-local model, enabling the system parameter deviation and the external disturbance to be uniformly equivalent to lumped disturbance, and designing a full-order sliding-mode observer for real-time estimation; calculating a reference voltage vector based on the disturbance estimation value and the extrapolated reference current; and an optimal double-vector combination is selected through space vector optimization, action time is solved, redundant small vectors are selected according to midpoint voltage deviation, and PWM driving signals are generated. According to the method, excellent current tracking performance and low harmonic distortion can still be kept under the conditions of parameter mismatch and working condition change, meanwhile, neutral-point potential balance on the direct-current side is achieved, and the method has the advantages of being small in calculation amount, high in robustness, easy to achieve in engineering and the like.
Owner:SHANDONG UNIV

Single-stage interconnection converter port power distribution method based on multilayer space vector modulation strategy

The invention discloses a single-stage interconnection converter port power distribution method based on a multilayer space vector modulation strategy. The method comprises the following steps: firstly, obtaining a single-stage interconnection converter alternating current side reference voltage vector through an energy management strategy, a power control loop and a current and voltage double closed loop of a hybrid alternating current and direct current micro-grid; then, the single-stage interconnection converter is subjected to equivalent decoupling modeling to form four virtual two-level converters, a four-layer space vector diagram is obtained, scaling factors for decomposing reference voltage vectors are calculated according to given reference power, and therefore the two reference voltage vectors on the alternating current side are decomposed into four independent voltage vectors; and synthesizing the four voltage vectors in a four-layer space vector diagram to obtain the duty ratio of each phase of the four two-level converters so as to obtain the switching sequence of the single-stage interconnection converter.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA

High-robustness deadbeat predictive current control method

The invention discloses a high-robustness deadbeat predictive current control method which is suitable for current control of a dual three-phase permanent magnet motor driving system, and belongs to the technical field of permanent magnet motor control. The method mainly comprises the following steps: reconstructing a motor mathematical model by adopting a space vector decoupling matrix and Park transformation to obtain a motor voltage equation under a dqxy axis; designing a linear expansion state observer; a reference value of an output voltage vector is obtained in combination with deadbeat predictive current control; time delay in the digital control system is calculated, and angle delay is compensated; and designing a closed-loop Smith predictor for compensating a time delay link to complete high-robustness dead-beat predictive current control of the dual three-phase permanent magnet motor. The current loop design in the method does not depend on motor parameters, and the method has high parameter change robustness. By introducing the closed-loop Smith predictor, large delay of the system can be effectively compensated, and high-precision current tracking is realized under low switching frequency.
Owner:ZHEJIANG UNIV

Motor vibration noise control method and system based on modal resonance frequency prediction

PendingCN121863928AImprovement of electromagnetic vibration noiseavoid balanceElectronic commutation motor controlElectric motor controlNoise controlVoltage vector
The invention provides a motor vibration noise control method and system based on modal resonance frequency prediction, and belongs to the field of motor control. The method comprises the following steps: acquiring each order of intrinsic mode frequency of the permanent magnet motor; a cost function parameter, a current constraint condition and a control target are set, and a model prediction control method is adopted to drive an inverter to operate, specifically, the current operation state quantity of the permanent magnet motor is collected; predicting a state response in a future finite time domain based on the operation state quantity; constructing a value function, and evaluating and optimizing a state change result; and selecting an optimal voltage vector, generating a pulse signal to drive an inverter to execute, obtaining a motor high-frequency electromagnetic force wave distribution condition, comparing the motor high-frequency electromagnetic force wave distribution condition with the intrinsic mode frequency of the permanent magnet motor, and optimizing an optimal voltage vector selection logic. The problems that harmonic waves are concentrated and resonance is easily caused by a fixed switching frequency modulation method in the prior art, and a passive suppression method is high in cost and poor in flexibility are solved.
Owner:SHANDONG UNIV +1

Parallel power supply system large disturbance stability analysis method considering coupling

The invention belongs to the field of inverter transient synchronous stability analysis, and discloses a coupling-considered parallel power supply system large disturbance stability analysis method, and the topological structure of a parallel power supply system comprises a network-constructing inverter, a network-following inverter, a line impedance and a power grid. The method specifically comprises the following steps: simplifying a topological structure of the parallel power supply system, constructing an equivalent circuit mathematical model of the parallel power supply system, and constructing a voltage vector expression at a common bus for analyzing a coupling interaction relationship between a network-constructing inverter and a network-following inverter; based on the control block diagram of the network-constructing type inverter, constructing a network-constructing type control ring mathematical model in the large-disturbance transient process of the network-constructing type inverter; the method solves the problems that in the prior art, the coupling influence of a grid-forming inverter and a grid-following inverter parallel power supply system is not considered sufficiently, and the transient stability under large disturbance is difficult to analyze accurately.
Owner:SOUTHEAST UNIV

Optimized virtual vector modulation strategy of T-type three-level inverter

The invention discloses an optimized virtual vector modulation strategy of a T-type three-level inverter, which is characterized in that a sector is re-divided based on the virtual vector modulation strategy, a synthesis mode of a virtual vector is optimized, a low-amplitude common-mode voltage vector is adopted to synthesize the virtual vector, on one hand, common-mode voltage generated by the inverter can be inhibited, and on the other hand, the common-mode voltage generated by the inverter can be inhibited; and on the other hand, the optimized modulation method does not influence the neutral point potential, the smoothness of the direct output voltage of the inverter is improved, the voltage quality is improved, and the method has the advantages of low harmonic content of the output current and the like. In addition, the method solves the problems of inverter output voltage distortion, common-mode voltage spike and the like caused by a dead zone effect through a voltage vector compensation method, and has guiding significance for improving the reliability of a photovoltaic system and a micro-grid system.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA

Power system short-circuit parameter prediction method, system and device based on space-time relevance and storage medium

The invention relates to the technical field of power grid safety evaluation, in particular to a power system short-circuit parameter prediction method, system and device based on time-space relevance and a storage medium. A multi-dimensional state vector including a node voltage vector, a branch current vector, a short-circuit impedance matrix, spatial position information and a time feature vector is constructed, and a space-time correlation feature vector including a time-dimensional feature, a spatial-dimensional feature, a space-time coupling feature and a state feature is extracted. Wavelet transform, Fourier analysis and graph theory analysis are adopted to identify a parameter change rule and a propagation effect. A multi-level prediction model of a statistical prediction layer, a deep learning layer and a fusion layer is constructed, and comprehensive description of dynamic characteristics of short-circuit parameters is realized through spatio-temporal feature fusion. A staged training strategy is adopted, and comprises the steps of establishing a basic model through offline training, updating parameters in real time through online learning, and quantifying uncertainty through a probability prediction framework. And a prediction correction mechanism and a reliability evaluation system are established, and a complete prediction-evaluation-correction closed loop is formed.
Owner:GUIZHOU POWER GRID CO LTD

Improved multi-vector combined model predictive control method and device for permanent magnet synchronous motor

The invention discloses an improved multi-vector combined model predictive control method and device for a permanent magnet synchronous motor. The method comprises the following steps: acquiring a three-phase current of each sampling period, and converting the three-phase current into a d-axis current and a q-axis current; performing one-beat delay compensation on the current, predicting a reference voltage of a next beat, and judging a sector where the reference voltage is located; selecting a corresponding voltage vector output combination in the reconstructed voltage vector selection table by combining the sector and the previous period zero vector; solving a cost function only containing voltage vectors and action time by using the KKT theorem, and calculating the action time of each voltage vector; and generating a pulse signal according to the action time for driving the output of an inverter of the permanent magnet synchronous motor. According to the method, the advantages of fast dynamic response, easy processing of multiple constraints and the like of model prediction control are maintained, and meanwhile, lower calculation complexity, fixed switching frequency and higher reliability are realized, so that the comprehensive performance of a permanent magnet synchronous motor control system is improved.
Owner:ZHEJIANG SCI-TECH UNIV

Spherical simplex robust unscented Kalman filter, PWM rectifier control method and device

The invention discloses a spherical simplex robust unscented Kalman filter and a PWM (Pulse Width Modulation) rectifier control method and device, which are characterized in that (2n + 1) Sigma points in standard unscented Kalman filtering are replaced by (n + 2) simplex vertexes which are symmetrically distributed on a unit hyper-sphere, so that the calculation complexity is remarkably reduced. A covariance matrix and a state quantity are dynamically adjusted in combination with a corrected observation noise covariance matrix and an adaptive factor adjustment mechanism, so that the estimation precision of the filter on the lumped disturbance quantity is remarkably improved, and the robustness and the tracking performance of the system on non-Gaussian noise and abnormal observation values are enhanced. And estimating the lumped disturbance quantity of the system in real time through spherical simplex robust unscented Kalman filtering, introducing the lumped disturbance quantity into a cost function for optimization solution, and selecting an optimal voltage vector to control the on-off state of the rectifier. According to the invention, the total harmonic distortion rate of the output current and the voltage fluctuation of the direct-current bus are obviously reduced under the steady-state condition, and higher response speed and stronger anti-interference capability can be shown under the dynamic working condition.
Owner:CHINA UNIV OF MINING & TECH

High-order analysis power flow and carbon flow tracking method based on full-pure embedding

The invention relates to a high-order analysis power flow and carbon flow tracking method based on full-pure embedding, and the method comprises the specific steps: introducing a complex embedding parameter s, constructing a node voltage vector, an injection power vector and a tracking matrix in a power grid power flow equation into an analysis power series and an analysis power series of the complex embedding parameter s based on the analysis continuation characteristic of full-pure embedding, solving a node voltage initial value when the power grid is in a basic operation state by adopting a Newton-Raphson method; calculating a zero-order line active power vector based on the node voltage initial value, and constructing a zero-order distribution matrix representing a power distribution relation in a basic operation state of the power grid; solving a zero-order power flow tracking matrix based on the zero-order line active power vector and the zero-order power distribution matrix; calculating node indirect total carbon emission based on the zero-order power flow tracking matrix; and replacing the power distribution matrix, the node outflow power and the power flow direction matrix in the zero-order power distribution matrix with power series expansion of corresponding variables.
Owner:FUJIAN AGRI & FORESTRY UNIV

Permanent magnet motor current prediction control method and device

The invention discloses a current prediction control method and device for a permanent magnet motor, and the method achieves the real-time prediction of a voltage error caused by a dead zone and other non-ideal factors through the powerful nonlinear fitting capability of a feedforward neural network in combination with the learning of historical current time sequence characteristics. And the prediction error is further fed forward and compensated to a future current prediction model to improve the accuracy of current prediction, so that the cost function evaluation is more accurate, the optimal voltage vector is selected, and the steady-state current error and the low-speed torque ripple are effectively inhibited. In this way, precise control over the current of the motor is achieved, and the control precision and operation stability of the driving system are comprehensively improved.
Owner:NINGBO STAR MATERIALS HI TECH

Online synchronous vector monitoring device and method for electrical parameter complex field of distribution transformer

The embodiment of the invention discloses a distribution transformer electrical parameter complex field on-line synchronous vector monitoring device and method, and the device comprises a high-precision synchronous vector measurement and collection module and a controller, and the high-precision synchronous vector measurement and collection module is connected with the controller. The high-precision synchronous vector measurement and acquisition module is used for being connected with a neutral line at the low-voltage side of the distribution transformer to be measured and a three-phase line at an outlet, and is used for measuring and synchronously acquiring a zero-sequence voltage vector and a neutral line current vector at the low-voltage side of the distribution transformer to be measured. The controller is used for determining the short-circuit complex impedance of the distribution transformer to be measured according to the zero-sequence voltage vector and the neutral current vector, so as to determine the load loss and the short-circuit voltage of the distribution transformer to be measured according to the short-circuit complex impedance, namely, the zero-sequence voltage vector and the neutral current vector are simply and synchronously measured on the low-voltage side of the distribution transformer. Therefore, on-line monitoring of short-circuit complex impedance and electrical parameters can be realized, and problems in the prior art are solved.
Owner:YUNNAN POWER GRID CO LTD ELECTRIC POWER RES INST

Fuel cell membrane electrode voltage distribution test method and system

The invention relates to the technical field of fuel cell membrane electrode voltage distribution testing, in particular to a fuel cell membrane electrode voltage distribution testing method and system, and the method comprises the steps: arranging a potential sensor array, and synchronously collecting an original voltage vector through the potential sensor array in the loading operation process of a fuel cell; a reference electrode is arranged in the non-reaction area, a stable reference signal is applied to the reference electrode, and a feedback signal of the reference electrode is collected after preset stable time is delayed; carrying out difference calculation on the feedback signal and the stable reference signal to obtain a system measurement drift distance; and performing joint calibration on the original voltage vector according to the system measurement drift amount and the spatial continuity constraint of the membrane electrode voltage distribution to obtain the voltage distribution vector of the fuel cell membrane electrode. And the authenticity and reliability of the voltage distribution data in the long-period test process of the fuel cell are ensured by continuously compensating the drift of the measurement precision.
Owner:DALIAN JINGYU TECHNOLOGY CO LTD

Matrix decomposition device and method based on memristor cross array

The invention relates to a matrix decomposition device and method based on a memristor cross array, which are suitable for efficient hardware implementation of singular value decomposition (SVD), the memristor cross array receives a conductance value mapped by a Grubrum matrix constructed by a to-be-decomposed matrix and a bit line input voltage converted by a bit line column vector, and outputs a corresponding current; converting the corresponding current into a voltage vector; performing normalization processing on the voltage vector to obtain a normalized vector; judging whether convergence occurs or not; performing normalization processing on the steady-state voltage vector to obtain a final output vector; and according to the final output vector, main characteristic values are extracted based on a first normalization circuit, and main singular values and corresponding singular matrixes are calculated. Compared with the prior art, the high parallel computing characteristic of the memristor cross array is utilized, efficient operation and hardware acceleration of matrix decomposition are achieved, the method has the advantages of being low in power consumption, high in speed and good in expansibility, and the method is suitable for application scenes such as artificial intelligence, signal processing and large-scale matrix operation.
Owner:SOUTHEAST UNIV

Sampling noise compensation-based model-free predictive current control system and method for LCL grid-connected inverter

The invention belongs to the technical field of electronic power, and particularly relates to an LCL grid-connected inverter model-free predictive current control system and method based on sampling noise compensation, and the system comprises an inverter main circuit, an LCL filter and a controller. The controller is configured to firstly calculate a current gradient and a voltage gradient according to a collected system operation signal; then, a second-order generalized integrator is used for conducting accurate compensation on sampling noise contained in the gradient; and finally, executing a model-free predictive control algorithm based on the compensated gradient, and preferably selecting an optimal voltage vector through a multi-objective value function integrating inverter side current, capacitor voltage and network side current. According to the method, sampling noise interference is effectively suppressed, the control precision and the anti-interference capability of the system are improved, and stable and efficient operation of the LCL grid-connected inverter can be realized without additional damping.
Owner:ANHUI UNIV