179 results about "Space vector" patented technology

The invention discloses a multi-modal data fusion method and system based on a large model, and relates to the technical field of data fusion, and the method comprises the steps: receiving multi-modal data, and carrying out the noise layering filtering and time-space alignment; mapping data to a large model hidden space through each modal lightweight encoder, extracting initial features by using a single-modal pre-training model, and converting the initial features through an adapter to generate a hidden space vector; each modal hidden space vector and a task cue word are received, a fusion feature matrix is dynamically aggregated and generated through a self-attention mechanism and a cross attention mechanism of a large model, and semantic integration of multi-modal information is realized; taking the fusion feature matrix as a soft label, and learning a cross-modal semantic mapping capability through knowledge distillation; the trained model is deployed to the edge through dynamic quantization and pruning optimization, an optimized feature matrix is input into a task-customized lightweight head network, and a final task result is output in combination with multi-modal context information. The method can break through the semantic gap between modals, and improves the fusion efficiency.

The invention discloses a transformer fault diagnosis and root cause positioning method based on a space-time diagram neural network, and relates to the field of transformer fault diagnosis, and the method comprises the steps: S1, carrying out the preprocessing of the structure information and DGA time series data of a transformer, and obtaining a topological network structure diagram and a DGA time series; s2, obtaining a spatial vector based on a message passing mechanism of a graph convolutional network; s3, a time sequence vector is obtained in combination with a Transform encoder and multi-head self-attention; s4, obtaining space-time fusion features; s5, constructing a multi-task prediction head based on the space-time fusion feature, the fault type historical data and the fault root cause; and S6, carrying out fault detection and outputting a corresponding fault type and root cause positioning result. According to the application, the accuracy of fault type identification can be remarkably improved, and accurate positioning of the fault root cause is realized.

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.

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.

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.

The invention provides a display screen dynamic control method and system, and relates to the technical field of data processing, the method comprises the following steps: constructing a space coordinate system comprising a plurality of entity nodes, the entity nodes comprising a display screen preset angular point, a user binocular vision center and a handheld interaction device; analyzing a relative pose relationship among the nodes by calculating a projection dot product of a space vector corresponding to each node; constructing a dynamic topology network based on the relative pose relationship, and synchronously collecting environment illumination intensity, user fixation point coordinates and user pose data; performing time sequence synchronization and Kalman filtering preprocessing on the acquired multi-modal data to obtain an initial feature set; and generating a spatial calibration coefficient according to the distribution characteristics of the dynamic topology network, and performing normalization compensation on the initial feature set through the calibration coefficient to obtain a calibrated multi-modal sensing feature vector. According to the invention, accurate and intelligent dynamic control is realized.

The invention relates to the technical field of network communication, in particular to an intelligent network card data forwarding method and system based on an FPGA, and the method comprises the steps: after the FPGA receives a data stream, firstly extracting a time interval standard deviation of N data packets as a time feature, executing parallel hash operation on a source IP address and a destination IP address, and mapping the source IP address and the destination IP address into three-dimensional coordinates; splicing the time features and the space coordinates into a two-dimensional matrix; a time vector T and a space vector S are separated from the two-dimensional matrix, the time feature similarity is calculated through cosine similarity, the space similarity is calculated through an Euclidean distance normalization algorithm, and affinity is obtained after weighted fusion; the condition that the affinity exceeds a first preset threshold value is used as a triggering condition for micro-flow slice splitting, and a data label is added to the slice; the FPGA intelligent network card implements heterogeneous channel binding based on slice affinity, and the global crossbar switch realizes non-blocking channel switching according to priority. And the slice splitting is triggered according to the affinity threshold, so that the high-speed transmission efficiency is improved.

The invention discloses an overhead line fault diagnosis method, system and device based on space vector conversion and a storage medium, and relates to the technical field of intelligent power distribution, and the method comprises the steps: collecting the normal operation three-phase current data of an overhead power distribution line, and constructing a steady-state feature model; three-phase current data is collected in real time and converted into a space vector sequence, the Euclidean distance between a vector end point and a model center is calculated, and instantaneous offset is extracted. Integrating the offset in a sliding window, calculating a phase rotation rate, generating a multi-dimensional deviation tensor, inputting the multi-dimensional deviation tensor into a fusion function to obtain a misconstruction score, and normalizing the misconstruction score to obtain a misconstruction index; comparing the index with a threshold value, if the index exceeds the threshold value, determining that the disturbance is external transient disturbance, and adjusting the sampling frequency of the current sampling device; according to the method, interference can be effectively identified in a special electromagnetic environment, misjudgment of diagnosis is avoided, maloperation of a protection device is reduced, reclosing operation is guaranteed, and the fault diagnosis accuracy and robustness of a power distribution system are improved.

The invention relates to the technical field of motor control in the intelligent power grid industry, and discloses a space vector control method for a twelve-phase permanent magnet synchronous motor flywheel energy storage system, a control circuit of the flywheel energy storage system relates to power electronic components such as various semiconductor field-effect tubes, and the space vector control method is used for high-precision control of a motor. Comprising the steps of S1, twelve-phase space vector decoupling fault-tolerant control, S2, high-order harmonic energy recovery closed loop, S3, quantum annealing parameter optimization layer, S4, flux linkage adaptive observer network construction and S5, 18-dimensional switching vector table construction. According to the scheme, through multi-reference coordinate system transformation and a redundant phase reconstruction algorithm, rapid fault-tolerant response of the twelve-phase motor during a single-phase or two-phase fault is realized, a current path is dynamically recombined during the fault, a negative-sequence current compensation ring is combined, torque ripple is effectively suppressed, and the reliability of the motor is improved under a high-speed charging and discharging working condition. The harmonic distortion rate is detected in real time through the sliding window FFT, the bandwidth of the controller is adjusted, and the problem that the dynamic response of a traditional fault-tolerant strategy is insufficient is solved.

The invention discloses a three-phase three-wire three-level hybrid modulation switching method and device and a medium, and the method comprises the following steps: obtaining a three-phase sinusoidal modulation wave, and superposing a primary common-mode voltage to obtain a continuous first modulation wave; if the continuous space vector control is executed, comparing the first modulated wave with a carrier wave to form a first duty ratio signal; if the intermittent space vector control is executed, superposing the first modulation wave and a secondary common mode voltage based on a unified coefficient to obtain an intermittent second modulation wave; and according to a specific mode of intermittent space vector modulation, assigning a value to the unified coefficient to obtain a corresponding target intermittent space vector modulation wave. The device and the medium are both used for implementing the method. The method has the beneficial effects that the degree of freedom of the algorithm can be maximized through a PWM unification and coefficient modulation strategy; compared with a traditional mode, the complexity of an algorithm can be effectively reduced, and the reliability of overall code execution can be improved.

This invention relates to a control and testing method for a three-phase current-source rectifier, comprising: obtaining the zero-crossing point of the three-phase input AC voltage using a software phase-locked loop method; initiating outer-loop control calculation at the zero-crossing point to stabilize the output voltage at the target value, with the output value of the outer-loop control serving as the fine-tuning value for the reference in the inner-loop PI closed-loop control; initiating the inner-loop PI closed-loop control, employing a direct current control method to achieve unity power factor; obtaining the αβ-axis space vector control variable through coordinate transformation of the output value of the inner-loop PI closed-loop control, and then obtaining a seven-segment PWM pulse through sector division and switching time calculation, which drives the MOSFETs in the main circuit; and performing detection by a host computer to obtain the change trajectory of key parameters and visualize the data. This invention not only achieves controllable output voltage of the current-source rectifier and simplifies the main circuit, but also improves the correctness of the space vector control algorithm and the reliability of rectifier operation through anti-saturation processing of the αβ-axis parameters in the stationary two-phase coordinate system.

The invention relates to a BIM (Building Information Modeling) data-driven steel member shape measurement method, which specifically comprises the following steps that: on the basis of design data of steel members, a BIM platform establishes overall BIM models of the steel members, and each overall BIM model of the steel members comprises a plurality of member assemblies; setting a laser emission point and a plurality of associated measured points for each component assembly; calibrating space vectors from the laser emission point to different associated measured points, and taking the space vectors as calibration data of the corresponding component assembly; performing field measurement on the component assembly of the actual steel component to obtain actually measured data of the component assembly; and comparing the calibration data with the measured data to obtain a qualification judgment result of the steel member. Compared with the prior art, the method has the advantages that space vector calibration is carried out after the center point of the end face of the component assembly deviates in the direction perpendicular to the end face, it is avoided that other structures shield the steel component, continuous three-dimensional profile data of the end face can be obtained, and the problem of missing measurement of the shape of the steel component is completely eradicated.

Method for operating switching elements (22, 24, 26, 28, 30, 32, 34, 36, 38, 40) of an inverter (12) to which a stator winding of an at least three-phase electric machine (14) is connected, wherein the inverter (12) has at least one series connection of the switching elements (22, 24, 26, 28, 30, 32, 34, 36, 38, 40) for each of the phases (L1, L2, L3, L4, L5) of the electric machine (14) in order to electrically couple the electric machine (14) to a DC link (16) connected to the inverter (12), wherein switching signals for the switching elements are determined by vector control and provided at a clock rate greater than a frequency of a fundamental oscillation of the phase voltages in order to provide respective phase voltages by the inverter (12). is, wherein the switching signals are determined depending on at least one first reference pointer, which is determined bythat, for the switching states of the inverter (12) achievable by the switching elements (22, 24, 26, 28, 30, 32, 34, 36, 38, 40), first voltage state vectors are determined in a corresponding first space vector system using a Fortescue transformation adapted to the number of phases of the electrical machine (14), wherein the first reference vector is determined depending on a superposition of at least two of the first voltage state vectors, wherein, for determining the at least one first reference vector, at least two first voltage state vectors are chosen, one of which is a long first voltage state vector and the other a medium or a short first voltage state vector, and, for superimposing a harmonic of the phase voltage with respect to the frequency of the fundamental oscillation, the switching signals are additionally determined depending on at least one second reference vector.which is coupled to the first reference vector depending on an order number of the harmonics and which is determined by determining second stress state vectors in a corresponding second space vector system, wherein the second reference vector is determined depending on a superposition of at least two of the second stress state vectors and wherein a separate modulation level is determined for the harmonic and a total modulation level is maximized depending on the separate modulation level.

A method is provided for reducing common mode voltages in a system that includes an inverter connected to a motor by a long cable by controlling switches of the inverter to generate voltage vectors that emulate a three-phase sinusoidal waveform by switching between adjacent active vectors and active vectors that are separated by 180 degrees, determining whether a phase angle of the vectors is increasing or decreasing, determining a decision angle within the sector which is a function of a duty cycle offset and a modulation index; and applying duty cycle manipulation rules, including: responding to an increasing phase angle that is less than the decision angle by setting a duty cycle of the adjacent active vectors to a duty cycle high value; and responding to an increasing phase angle that is greater than 60 degrees minus the decision angle by setting the duty cycle to a low value.

The invention discloses a distributed computing task dynamic allocation system based on multi-graphics card collaboration, which relates to the technical field of graphics card collaboration, and comprises a space-time state detection module, a task feature analysis module, a multi-dimensional computing module and a dynamic scheduling decision module, the task feature analysis module is used for analyzing task description of an external task queue and obtaining a space vector and a time vector, and the multi-dimensional calculation module is used for carrying out multi-dimensional analysis on the graphics card according to the graphics card hardware state data, the space vector and the time vector and calculating the graphics card according to the graphics card hardware state data, the space vector and the time vector. Comprising a space resource dimension, a time dimension, cross-graphics card time sequence synchronization and fragment risk analysis to update an alternative graphics card list and a dynamic scheduling decision module, and on the basis of a multi-dimensional calculation module, the qualification that each graphics card can allocate a corresponding task is analyzed.

The invention provides a rapid flexible switching method for a permanent magnet synchronous motor winding reconstruction circuit, and belongs to the technical field of permanent magnet synchronous motor winding reconstruction. In order to solve the problems of surge voltage, impact current, torque drop and even torque interruption generated in a motor winding reconstruction transient state and relatively long transient state reconstruction time in an existing permanent magnet synchronous motor winding reconstruction method, the method comprises the following steps: step 1, in a zero vector interval of space vector pulse width modulation, carrying out space vector pulse width modulation; the permanent magnet synchronous motor winding reconstruction circuit enters a reconstruction transient state; 2, forming three different natural follow current loops of a mode 1, a mode 2 and a mode 3 by utilizing the combination of the switching states of the motor winding, the inverter, the series reconfiguration switch and the parallel reconfiguration switch, and adjusting the length of a zero vector interval required by winding reconfiguration according to the operation condition; and step 3, completing all reconstruction transient states in a zero vector interval of space vector pulse width modulation, and realizing switching of motor winding connection modes.

The application relates to a modulation method and device of a photovoltaic grid-connected inverter, an inverter and a storage medium, the modulation method comprising the following steps: under a preset carrier ratio condition, determining a first voltage vector based on collected direct-current bus voltage and three-phase voltage of the inverter; generating a virtual vector based on a basic voltage vector of a preset two-level inverter space vector diagram to obtain a first virtual vector and a second virtual vector; selecting a target vector from the basic voltage vector and the calculated virtual vector, synthesizing a second voltage vector equivalent to the first voltage vector by using the target vector, determining a target switching sequence corresponding to the second voltage vector; determining the duty cycle corresponding to each kind of vector in the corresponding target vector according to the target switching sequence, and modulating the inverter by using the pulse modulation PWM pulse determined by the corresponding duty cycle. Through the application, the problems of high low-order harmonic content and poor inverter output waveform quality of a two-level inverter synchronous modulation method are solved.

The invention relates to a power prediction control method of a doubly-fed motor converter under a three-phase imbalance condition. The power prediction control method comprises the following steps: step 1, constructing a power prediction model of a three-phase voltage source converter under a three-phase power grid voltage imbalance state; 2, predicting a six-power component change value of the three-phase voltage source converter in the next control period based on the power prediction model; step 3, setting a value function and calculating the action duration of the voltage vector in the next control period by minimizing the function; and 4, realizing power switch control of the three-phase voltage source converter by adopting a space vector pulse width modulation technology. The method has the advantages that the active power, the reactive power and the harmonic components of the three-phase voltage source converter with the alternating-current-to-direct-current conversion function in the doubly-fed motor speed regulation system can be controlled under the condition that the three-phase power grid voltage is unbalanced, and the purpose of improving the efficiency and the control performance of the doubly-fed motor speed regulation system is achieved.

The application discloses a permanent magnet synchronous motor model prediction torque control method based on a hybrid mode optimization. The method first constructs a reference voltage vector through a torque error target function and a discretization prediction model of the permanent magnet synchronous motor, and then designs a hybrid mode optimization algorithm. The algorithm first designs a double-vector mode optimization on the sector boundary of a voltage space vector diagram, and then designs a three-vector optimization mode based on a discrete space vector modulation inside the sector. The optimal synthesized voltage vector obtained by the hybrid mode optimization algorithm is transmitted to a voltage error target function to realize the switching of the two modes, so that the control execution mode and the optimal synthesized voltage vector are determined. The control method disclosed by the application has high freedom to adjust the amplitude and position of the synthesized voltage vector, and thus has high steady-state performance of the control system and fast torque dynamic response in the full speed range.

The invention provides a control method and system for a low-cost five-level rectifier, and the method comprises the steps: obtaining an output voltage and a current value of the low-cost five-level rectifier, and calculating a voltage reference value at a next moment through a model prediction algorithm; performing coordinate transformation on the reference voltage value to obtain a reference voltage vector at the next moment; determining a voltage vector closest to the reference voltage vector as an optimal space vector according to the space vector diagram of the low-cost three-phase five-level rectifier; and on the basis of the optimal space vector, according to a three-phase level combination in the vector, the switch combination state of a common module and each phase independent module of the low-cost five-level rectifier is controlled, and the control target of neutral-point voltage balance and suspension voltage balance is achieved. According to the invention, control of the neutral-point voltage and the floating capacitor voltage is realized.

The invention provides a permanent magnet synchronous motor sensorless control strategy based on an improved phase-locked loop. The method comprises the following steps: constructing a permanent magnet synchronous motor model driven by a three-leg inverter; rotating speed closed-loop and current closed-loop control is adopted, a rotating speed controller and a current controller both adopt proportional-integral controllers, and a modulation strategy is SVPWM (space vector pulse width modulation); building a Luenberger observer model, estimating a back electromotive force by taking the acquired voltage and current as input quantities, and then filtering out higher harmonics in a back electromotive force signal by adopting a synchronous frequency extraction filter; and building a dual high-order phase-locked loop, and finally obtaining rotor position information and rotating speed information of the permanent magnet synchronous motor by compensating a position estimation error of the phase-locked loop (PLL). The method can effectively solve the problem that a phase-locked loop has a large estimation error when the position of the rotor is estimated, reduces steady-state errors of the permanent magnet synchronous motor during acceleration or deceleration operation, filters out higher harmonic components in counter electromotive force, and improves the precision of a permanent magnet synchronous motor control system.

The invention provides a motor harmonic suppression method and system and a storage medium, and relates to the technical field of motor control, and the method comprises the steps: obtaining the multi-phase current of a motor; performing space vector decoupling transformation on the multi-phase current to obtain a current component of a harmonic XY plane; 6 < K-1 > harmonic waves and 6 < K + 1 > harmonic waves of the current component are converted into 6 < K > harmonic waves, and K is a positive integer; performing normalization processing on 6K-1 harmonic waves and 6K + 1 harmonic waves of the current component based on the 6K harmonic waves to realize amplitude reconstruction; performing six-frequency-multiplication rotation angle conversion on the normalized current component to generate a direct current quantity; generating a compensation voltage based on the DC amount; and injecting the compensation voltage into a control loop of the motor to suppress harmonic waves. The method aims to carry out key suppression on 6K-1 harmonic and 6K + 1 harmonic of a harmonic XY plane, the efficiency of a motor control system is improved, and global harmonic suppression of a double Y30 six-phase motor can be realized.

The invention discloses a three-level inverter neutral-point voltage balance control method and system and a vehicle, and the method comprises the steps: determining a target d-axis current based on a requested d-axis current and a neutral-point voltage deviation, and then determining a target q-axis current; carrying out current closed-loop control, carrying out SVPWM (Space Vector Pulse Width Modulation), and outputting positive and negative small vector action time and a sector where a voltage vector is located; pI adjustment is carried out on the neutral-point voltage deviation to obtain a neutral-point voltage compensation value; based on the sector where the voltage vector is located, the capacitance value of the three-level inverter thin-film capacitor and the three-phase current, the neutral-point voltage compensation value is subjected to linearization processing, and a positive and negative small vector action time compensation value is obtained; compensating the positive and negative small vector action time by using the positive and negative small vector action time compensation values; and controlling the operation of the three-level inverter based on the action time of the compensated positive and negative small vectors. According to the invention, the calibration difficulty of the neutral-point voltage PI adjustment parameter can be reduced, and the neutral-point voltage balance controllability can be improved.

The invention discloses a high-speed permanent magnet synchronous motor position identification method, which comprises the following steps of: sampling a, b and c three-phase current of a motor, performing Clarke conversion on the obtained current to obtain alpha-axis and beta-axis current on a two-phase static coordinate system, estimating output voltage of the alpha-axis and beta-axis according to SVPWM (Space Vector Pulse Width Modulation) conduction time calculated in the previous control period, and identifying the position of the high-speed permanent magnet synchronous motor according to the output voltage of the alpha-axis and beta-axis. A position estimation reference quantity is obtained by directly processing current and voltage, the angle and the rotating speed of the position estimation reference quantity can be calculated by using a phase-locked loop, and the position information of the motor is calculated according to the angle and the rotating speed. And the position identification precision under a low carrier frequency ratio is improved.

The invention discloses a beam forming method based on delay Doppler domain channel parameter prediction in a high-speed mobile communication system, and relates to the technical field of wireless communication, in particular to a beam forming method. The invention aims to solve the problem of wave beam mismatch at the future moment caused by CSI aging in high-speed mobile communication. The method comprises the following steps: 1, obtaining a channel response matrix and a power spectrum in a DD domain; 2, obtaining an estimated value of an angle of arrival, Doppler and time delay; 3, obtaining a final cluster set and an adaptive threshold; 4, calculating a space vector; calculating an angle of arrival based on the spatial vector; calculating a cluster direction vector based on the angle of arrival; calculating a sub-modal Doppler center and a sub-modal space vector; calculating sub-modal equivalent gain estimation of each group in each cluster; and 5, obtaining a prediction channel based on the complex gain propulsion prediction of each group in each cluster, and obtaining a prediction beam based on the prediction channel.

Control system (24) for controlling the operation of a multiphase electrical machine (19), comprising: a signal generator (210) configured to generate a number n of duty cycle signals of a pulse width modulation (PWM) scheme as a combination of a continuous PWM scheme and a non-continuous PWM scheme, the combination being based on a value of a mixing coefficient Σ; wherein the signal generator (210) is configured to use each of the duty cycle signals to control the switching of a DC power to a corresponding phase of the multiphase electrical machine (19); wherein the signal generator (210) is configured to use a mixing function to determine a relative weighting of both the continuous PWM scheme and the non-continuous PWM scheme to generate the number n of duty cycle signals;wherein the mixing function is calculated on the basis of a difference between the value of the mixing coefficient γ and two thresholds a1, a2; and wherein the duty cycle signals are generated via the combination of the continuous PWM scheme and the discontinuous PWM scheme, based on the fact that the value of the mixing coefficient γ is greater than or equal to a first threshold a1 and less than a second threshold a2, where the second threshold a2 is greater than the first threshold a1; characterized in that n is an integer greater than 3 and that the mixing function determines the mixing coefficient γ as a function of the modulation index mi and a phase current Is using the following formula: γ(mi,Is)={0.50≤γ; <a10.5×(1−&lgr;−a1a2−a1)a1≤&lgr;<a20a2≤&lgr;<1wobei &lgr; eine Zwischenvariable ist, die definiert ist durch:&lgr;(mi,Is)=b⋅IsIsmax+(1−b)⋅mi,0≤b≤1 where b is a tunable constant and Ismax is the maximum current of the multiphase electric machine (19).;

The application discloses a control method of a current source type converter based on a bidirectional switch, which comprises the following steps: firstly, obtaining a current sector where a three-phase current space vector is located; secondly, sampling three-phase voltages of the current source type converter by using a voltage detection circuit; thirdly, dividing the whole working interval into a main interval and a transition interval according to the three-phase voltage values; fourthly, using the same vector distribution table in the main interval and the transition interval; fifthly, not limiting the type of zero vector in each current sector; sixthly, adopting a two-step commutation mode in the main interval; seventhly, adopting a four-step commutation mode when commutation is performed between two phases with relatively close voltage values in the transition interval; and eighthly, adopting the two-step commutation mode in other cases. The control method can reduce the commutation time of the current source type converter, reduce the common-mode voltage in the transition interval of the converter, and reduce harmonic distortion, so as to guarantee the efficient and reliable operation of the current source type converter system.

Embodiments of the present application disclose a grid-connected inverter control method, device, equipment and storage medium. The grid-connected inverter control method comprises: calculating a grid voltage prediction value in a two-phase stationary coordinate system in a current period according to a grid voltage sample value in the two-phase stationary coordinate system in a previous period, a variation angle of a three-phase grid voltage space vector and a preset numerical relationship; judging whether a grid voltage drop occurs according to a numerical relationship between an absolute value of a difference between the grid voltage sample value in the two-phase stationary coordinate system in the current period and the grid voltage prediction value and a preset voltage value; and controlling the grid-connected inverter according to a judgment result. The technical scheme of the embodiments of the present application is helpful to improve the judgment speed of the grid voltage drop, thereby relieving the problem of the grid voltage drop and improving the adaptability of the grid-connected inverter to the grid voltage drop.

The application relates to a kind of LCL type photovoltaic grid-connected inverter control method and device based on feedforward compensation, method includes obtaining the grid voltage of inverter, calculating the component of grid voltage in two-phase stationary coordinate system, calculating the difference of grid voltage and voltage instruction value, the reference current signal is obtained by PI regulation and coordinate transformation calculation to difference;Obtain the current on the side of inverter, actual current signal is obtained by coordinate transformation;The difference of reference current signal and actual current signal is calculated, input QPR regulator, obtain reference modulation signal;Obtain the capacitance current of inverter, calculate the difference with reference modulation signal, carry out internal damping feedforward compensation based on PFC after gain, recalculate difference, gain to obtain output voltage instruction value;After coordinate transformation to three-phase stationary coordinate system, input space vector pulse unit to obtain SVPWM waveform, input inverter to control.Compared with prior art, the application has the advantages of simple control means, good control effect and the like.