186 results about "Space vector modulation" patented technology

The present invention provides a wind power off-grid hydrogen production power supply topology and control method without a step-down transformer, including: obtaining wind speed data, using a wavelet threshold algorithm for denoising, predicting power based on an LSTM-GRU hybrid neural network, and extracting power fluctuation characteristics through multi-scale entropy analysis; obtaining load data, using Kalman filtering and recursive least squares to establish an impedance model, and extracting dynamic characteristics in combination with Hilbert transform; using a differential evolution algorithm for multi-objective optimization to generate an optimal switching sequence and power allocation strategy; achieving system control through space vector modulation, balanced control, soft switch control and harmonic compensation; achieving state estimation and disturbance suppression based on a sliding mode observer and a nonlinear observer; and achieving fault diagnosis and protection using a deep belief network. The present invention improves system efficiency and reliability and improves dynamic performance.

The invention relates to the technical field of motors, in particular to a space vector modulation method of a five-phase series end winding permanent magnet synchronous motor, which comprises the following steps of: drawing voltage vector distribution; dividing a maximum modulation domain; obtaining a three-dimensional space modulation domain and a two-dimensional space modulation domain, obtaining a basic voltage vector adjacent to a sub-tetrahedron where each reference voltage vector is located and a duty ratio of the basic voltage vector, and judging whether each reference voltage vector is over-modulated or not; performing overmodulation on each reference voltage vector in the three-dimensional space modulation domain and the two-dimensional space modulation domain; if the duty ratio of the upper bridge arm is larger than 1, a double-sampling-period modulation strategy is adopted for modulation; and the switch sequence is centrally symmetrical and then input to a five-phase six-bridge arm series end winding inverter. According to the method provided by the invention, the reference voltage can be tracked with relatively high precision, the harmonic current and the zero-sequence current can be effectively suppressed, and the method has relatively high DC bus voltage utilization rate.

The invention provides a three-phase SVPWM grid-connected inverter harmonic control method based on an improved particle swarm algorithm, and relates to the field of grid-connected control. On the basis of double closed-loop control of a three-phase SVPWM grid-connected inverter, a main circuit topological structure of the grid-connected inverter is firstly provided, and a mathematical model of the grid-connected inverter is determined; then determining a double-closed-loop control strategy based on space vector modulation according to the mathematical model; and aiming at a voltage outer loop and a current inner loop of the double-closed-loop control strategy, an improved particle swarm optimization algorithm is adopted to optimize PI parameters. According to the improved inertia weight, the minimum value, the maximum value and the fitness function of the inertia weight are comprehensively considered, a harmonic suppression performance index is added to the fitness function, and the improved particle swarm optimization algorithm enhances the global search capability and the accurate search capability, so that the probability of falling into a locally optimal solution is reduced. According to the control method, the grid-connected process of the grid-connected inverter can be more stable, the anti-interference capability is enhanced, the static error is reduced, and the electric energy quality is improved.

The invention discloses a permanent magnet synchronous motor high-performance prediction control method based on a sliding-mode observer, and the method comprises the steps: S1, collecting the position and mechanical angular velocity information of a rotor, collecting the three-phase voltage and current data of a permanent magnet synchronous motor, and converting the three-phase voltage and current data into the voltage and current of a motor stator under a two-phase rotating coordinate system; s2, constructing a speed ring sliding-mode observer, estimating electrical and mechanical parameter perturbation interference and load torque interference on line, designing a rotating speed ring deadbeat prediction controller, outputting reference current at the next moment, and setting the amplitude limit of the output reference current; s3, a current loop sliding mode observer is constructed, electrical parameter perturbation interference is estimated online, a current loop prediction controller is designed in combination with the dead-beat prediction control principle, and voltage at the next moment is output; and S4, carrying out amplitude limiting modulation on the output voltage, obtaining a voltage under a static coordinate system through Park inverse transformation according to the voltage after amplitude limiting modulation, and outputting a switching signal to a three-phase inverter by combining a two-level space vector modulation module to drive the permanent magnet synchronous motor to operate.

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 discloses a flux linkage tracking full-speed-domain high-precision predictive current control method for a permanent magnet synchronous motor, and the method comprises the steps: sampling a phase current signal, a position signal and a speed signal of the permanent magnet synchronous motor, and obtaining a dq sampling current through coordinate transformation; calculating a predicted current according to the established tracking discrete model; the sinusoidal variation characteristic and the dynamic transient characteristic of the resistance voltage drop are accurately considered in the current prediction and reference voltage calculation stage, and the resistance voltage drop is accurately represented through accurate feed-forward compensation of predicted current and reference voltage; a driving signal of the inverter is obtained through coordinate transformation and space vector modulation, and full-speed-domain high-precision fast-response current prediction control over the permanent magnet motor is achieved. According to the method, the current flow steady state control error caused by the model error is reduced, the current control precision and the dynamic response performance of the permanent magnet synchronous motor in the full-speed domain are effectively improved, and a high-precision model basis is provided for high-precision position-free control and parameter online identification.

The invention relates to the technical field of motor control, and particularly provides a control method and system suitable for a one-way running motor of a two-wheeled electric vehicle. The method aims to solve the problems of unstable motor operation and insufficient reliability caused by torque pulsation in the prior art. The method comprises the following steps: executing off-line identification of motor parameters to obtain initialized parameters; multi-source operation state signals are collected, and a vehicle working condition judgment result is obtained through fusion analysis; performing fault diagnosis and grading evaluation to form a fault-tolerant instruction; dynamic dead zone compensation and self-adaptive overmodulation are implemented by combining the parameters and the working conditions, and an optimization control instruction is output; generating a PWM driving signal through space vector modulation; and responding to the fault-tolerant instruction, and fusing a sensorless algorithm and a health sensor signal to realize degraded operation. According to the invention, the smoothness and efficiency of motor operation and the fault-tolerant capability of the system are effectively improved.

The invention discloses a model-free control method for a driving motor of a deep-sea robot. The model-free control method comprises the following steps: acquiring the position, rotating speed and bus voltage of the motor and phase currents of different stator modules; acquiring a rotating speed sampling value to predict the rotating speed and rotating speed ring disturbance at the next moment; acquiring a rotating speed instruction, calculating an electromagnetic torque instruction by combining the rotating speed and a rotating speed loop disturbance prediction value, converting the electromagnetic torque instruction into a current instruction, and averagely distributing the current instruction to each stator module; injecting current into the d axis, and acquiring a current sampling value to predict current and current loop disturbance at the next moment; obtaining a current instruction and calculating a voltage instruction by combining the predicted values of the current and the current loop disturbance; obtaining a gradient function for an adaptive adjustment system and adaptively adjusting a coefficient based on a finite time gradient descent method; and S3, based on the voltage instruction in the step S3, generating a PWM pulse signal through coordinate transformation and space vector modulation, and driving each stator module inverter to control the operation of the motor.

The invention relates to a method for improving the grid-connected stability of a grid-forming type inverter based on inductive current feedforward and coupling enhancement, and belongs to the technical field of inverter control. The method comprises the following steps: measuring inverter port voltage and filter inductive current, and calculating output active power and reactive power; calculating a port voltage reference value according to the amplitude and phase angle reference of the port voltage generated by the active controller and the reactive controller respectively; and taking the port voltage as a feedback value of the voltage regulator, and subtracting the feedback value from the port voltage reference value to serve as the input of the voltage regulator. And then adding the feedforward inductive current to the output of the voltage regulator to obtain a current reference value, and subtracting the inductive current from the current reference value to serve as the input of the current regulator. And finally, the output of the current regulator is added with the feedforward port voltage and combined with the cross-coupling enhanced voltage to obtain a modulation signal, and the modulation signal is subjected to space vector modulation to generate a driving signal so as to control the inverter. According to the method, on the premise that hardware cost and software complexity are not increased, the stable operation capacity of the grid-forming inverter under the strong power grid working condition is improved.

Embodiments of the present disclosure relate to a method, device and medium for reducing noise of a motor, the motor being a permanent magnet synchronous motor based on vector control, the method comprising performing interruptions on the motor at a first frequency and a second frequency, respectively, based on a predetermined timing sequence; when the interruption is executed on the second frequency, performing filtering processing on a vector control PWM duty ratio signal of the motor by using a multi-order weighted sliding mean filter so as to filter out a high-frequency harmonic component; performing compensation of the target phase compensation amount on the rotor angle of the motor when the interruption is performed on the first frequency; and performing space vector modulation on the interrupted output of the vector control PWM duty cycle signal of the motor, thereby obtaining the PWM duty cycle signal for reducing the noise of the motor.

The invention relates to the technical field of voice recognition and intelligent household electrical appliance control, in particular to an induction cooker control method based on voice recognition, which comprises the following steps: synchronously acquiring a voice signal and a lip motion signal, and generating multi-modal sensing data through timestamp alignment; performing cross-modal anti-noise processing on the data, and outputting a fusion feature tensor fusing acoustic and visual features; semantic analysis and danger instruction recognition are executed, and a risk filtering control instruction containing temperature / fire parameters is generated; calling a thermodynamic dynamic model to calculate a power control parameter based on the instruction parameter; converting a power parameter into a space vector modulation waveform to drive a load circuit, and synchronously collecting the pot bottom temperature; and triggering an anti-noise process and thermodynamic model parameter updating according to the deviation between the actual temperature and the target temperature. Noise interference is reduced through multi-modal signal cross validation, dangerous instructions are intercepted in combination with knowledge graph constraints, the noise suppression capability and the temperature control precision are continuously optimized, and the safety and reliability of voice control in a complex environment are improved.

The invention discloses an LC filtering type permanent magnet motor system prediction flux linkage control method and system and a medium, and belongs to the field of power electronics and power transmission. State variables of an LC filtering type permanent magnet motor system at the k moment are sampled, a discrete state-space equation of the system is established by adopting a zero-order retainer method, and a stator flux linkage vector prediction model is established; obtaining a stator flux linkage vector reference by using the electromagnetic torque reference and the parameters of the permanent magnet motor; constructing a loss function, and solving an inverter optimal control vector reference considering the system voltage constraint; park inverse transformation is referred to for the optimal control vector of the inverter, control pulses are generated through space vector modulation and act on an inverter switching tube, and LC filtering type permanent magnet motor system predictive flux linkage control is completed. According to the method, common control of the torque and the flux linkage can be realized only by controlling the stator flux linkage vector, and excellent torque flux linkage control performance can be obtained without any design parameter.

The invention provides a permanent magnet motor continuous set model-free predictive control method based on Bayesian optimization, and relates to the field of permanent magnet synchronous motor control. The method comprises the following steps: acquiring a hyper-local model and an extended state observer; determining the bandwidth and the input gain as optimization variables, and obtaining a training set and a test set for Bayesian optimization; joint probability distribution of the training set and the test set is calculated through a kernel function, and a prediction mean value and a prediction variance of optimization variables are determined; an optimization variable combination is screened based on the expected value collection function, and the bandwidth and the input gain are updated based on the optimization variable combination; based on the updated extended state observer and the hyper-local model, calculating the reference voltage of the next control period by using a dead-beat control principle; the reference voltage is decomposed into basic voltage vectors through space vector modulation, and the switching sequence of the basic voltage vectors is executed according to the minimum switching times to drive the permanent magnet motor. The method is not affected by motor parameter changes, and the current prediction control steady-state performance can be improved.

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.

The invention relates to the field of motor driving, in particular to a permanent magnet motor low-stagnation data driving prediction control method, system and product, and the method comprises the following steps: S1, obtaining the sampling data of a motor stator, and constructing a data driving model; s2, judging whether the sampling data is stagnated or not; s3, performing data component optimization on the sampling data; s4, when the stagnation does not occur, using the sampling data to update the data driving model; s5, performing Park conversion on the update current # imgabs0 # and # imgabs1 # output in the step S3 or the step S4; s6-S7, updating the data driving model by using the current # imgabs2 # subjected to Park conversion in the step S5, wherein the current # imgabs2 # is subjected to Park conversion in the step S5; s8, carrying out super localization on the predicted current; s9-S10, designing a control equation, and performing space vector modulation to output null control pulses; and ineffective components in the sampled data are deeply excavated and utilized, so that the stagnation phenomenon is reduced, and the current control quality is improved.

The invention relates to the technical field of generator control, and discloses an intelligent vehicle-mounted high-power self-generating control method and system. The method comprises the following steps: acquiring operating parameters of a generator set, performing high-precision digital processing, realizing constant-rotating-speed control through cooperation of multiple controllers based on a rotating-speed fluctuation characteristic value, performing power factor correction through coordinate transformation and active rectification to obtain a direct-current bus voltage, performing precise voltage stabilization by adopting a multi-phase interleaving converter, and outputting the direct-current bus voltage. And finally, outputting a high-quality three-phase alternating-current power supply through space vector modulation and closed-loop feedback control. The technical problems in the prior art that the power supply quality control capability is insufficient, the intelligent level is low, the environmental adaptability is poor, the load adaptability is limited, and the maneuverability is limited are solved.

The invention provides an SVG current adjustment method and system of a photovoltaic power station, and belongs to the technical field of SVG current adjustment. The method comprises the following steps: acquiring a current signal and a voltage signal based on a transformer deployed by SVG; calculating the current deviation, and analyzing the voltage fluctuation condition based on the collected voltage signal to predict the operation state of the power grid; selecting an SVG current adjustment strategy according to the calculated current deviation and the predicted power grid operation state; generating a corresponding adjustment instruction by using the selected SVG current adjustment strategy; and according to the adjustment instruction, controlling the switching action of a power device of the SVG so as to adjust the output current of the SVG. According to the invention, through various SVG current adjustment strategies, the method can adapt to working conditions and current deviation so as to ensure the stability and accuracy of SVG output current; through feedforward decoupling control and a space vector modulation technology, rapid and stable execution of an instruction is ensured, power consumption is reduced, and service life attenuation of equipment is inhibited.

The invention belongs to the technical field of motor driving control, and discloses a space vector modulation strategy method for a permanent magnet synchronous motor, which comprises the following steps of: searching a region division and vector arrangement table by using regions in which Vlp and V are positioned to obtain an optimal vector sequence, and arranging vectors based on a principle of eliminating a peak of a CMV and minimizing switching operation times; and finally, calculating the duty ratio of a plurality of effective voltage vectors used for synthesizing the next period according to the amplitude-second balance principle. Compared with a control strategy that only one effective vector or two adjacent effective vectors are used in each control period, the virtual vector synthesized by the method is the same as the reference vector, and common-mode voltage spikes can be eliminated by the method; compared with NSPWM and AZPWM, the method has the advantages that area division and vector sorting are reasonably arranged, so that the switching action times are minimized, the switching loss is reduced, and the inverter efficiency is improved.

The invention provides a method for reducing input current harmonic distortion of a Vienna rectifier of an electric vehicle charging module. Belongs to the technical field of power electronic switching, and comprises the following steps: comparing an actual DC voltage with a reference DC voltage, calculating an error signal, and processing the calculated error signal through a voltage regulator to generate a reference voltage; and generating a three-phase current reference signal according to the phase and the amplitude of the power grid voltage. Through the technical scheme of the invention, the low-order current harmonic of the source side current can be selectively eliminated without depending on current / voltage conversion, a phase-locked loop or a space vector modulation module, so that the calculation requirement is remarkably reduced; due to the fact that the calculation requirement is obviously reduced, the transient response speed of the method is higher.

The invention discloses a motor torque ripple suppression method based on integral proportion and quasi-proportional resonance control, and belongs to the technical field of motor control, and the method comprises the following steps: S1, obtaining the actual position of a motor rotor through the sampling of a sensor, and calculating the rotating speed n of the motor rotor; s2, the difference between the current rotating speed and the target rotating speed is obtained, and idref and iqref needed by current control are obtained through an integral proportion and quasi-proportional resonance comprehensive controller; and S3, performing subtraction between the idref and the id and between the iqref and the iq, obtaining uq and ud through a PI controller, inputting the uq and ud into a space vector modulation module after inverse Park conversion, and outputting a PWM control signal to control the motor. According to the invention, the torque pulsation with known frequency can be effectively inhibited, the speed pulsation is reduced by about 82%, and the stability of a speed ring is obviously improved; the response speed is obviously improved, and the aim of optimization design is achieved.

A multi-source inverter (MSI) topology features significant advantages over conventional MSI converters such as NPC-based and T-Type-based topologies, including a lower number of switching devices, higher efficiency, and better thermal distribution of switching devices. A space vector modulation (SVM) scheme for MSI topologies presented herein and for conventional MSI topologies uses three or four adjacent vectors to generate a reference voltage vector, resulting in lower voltage and current total harmonic distortion (THD) at the MSI output, a lower switching frequency, and increased efficiency relative to conventional MSI modulation. Embodiments are suitable for use in electric vehicles and energy storage systems.

The invention provides an autonomous synchronous network construction control method for parallel operation of a network construction type energy storage converter. The method comprises the following steps: collecting a grid-connected point voltage and a grid-side current of the energy storage converter; performing active power adjustment according to the grid-connected point voltage, the grid-side current and an active power instruction to obtain an output voltage phase; determining an adjustment deviation according to the grid-side current, the energy storage filter parameter, the first voltage instruction and the second voltage instruction; adjusting the adjustment deviation to obtain a virtual internal potential amplitude; and according to the virtual internal potential amplitude, the output voltage phase, the grid-connected point voltage and the grid-side current, voltage regulation, current regulation, coordinate system transformation and space vector modulation are carried out in sequence, and a driving signal required by control of the grid-forming type energy storage converter is generated. According to the method provided by the invention, the output voltage is adjusted by depending on the output capability of the energy storage converter, and the voltage adjusting capability is improved while the stable operation of the energy storage converter is maintained.

The invention provides a vehicle differential steering control method based on motor modulation, terminal equipment and a storage medium. The problems that in the prior art, the response speed is low, the control precision is low, and complex road condition changes are difficult to adapt are solved. Comprising the following steps: periodically acquiring real-time rotating speed signals of left and right wheel motors, and averaging the real-time rotating speed signals through a moving average filtering algorithm; and comparing the average rotating speed data of the left and right wheels, and judging whether the vehicle tends to turn leftwards or rightwards or not. Calculating the expected steering radius and the current linear speed according to a differential control algorithm, determining the due rotating speed difference of left and right wheels, and adjusting the rotating speed of the motor. Factors such as an Ackerman steering geometric model, a road adhesion coefficient and a side slip angle are introduced, and calculation of the steering radius is optimized. A three-phase driving signal is generated through space vector modulation, the on-off state of a three-phase inverter is controlled, and accurate speed control is achieved.

The invention relates to a model-free predictive current control method and system for a permanent magnet synchronous motor based on a least square method, and the method comprises the steps: building a first-order hyper-local model of the permanent magnet synchronous motor through a hyper-local model principle, and estimating an unknown part and a disturbance part in the hyper-local model through employing the least square method; and finally, generating a switching signal of an inverter through space vector modulation (SVPWM) so as to control the motor. Compared with traditional model prediction control, the control effect of the method does not depend on motor parameters, phase current THD can be reduced, dq-axis current ripples are reduced, and high robustness and anti-interference performance are achieved.

The invention discloses a three-phase energy storage converter dynamic parameter modulation method and a related device thereof, and the method comprises the steps: configuring a modulation strategy of a grid side 3-1MC matrix converter as a current space vector modulation strategy, configuring a modulation strategy of a DC side H bridge as a phase shift modulation strategy, introducing a modulation duty ratio coefficient # imgabs0 # as a modulation parameter, and carrying out the phase shift modulation of the DC side H bridge; the modulation parameters are reduced to modulate a duty ratio coefficient # imgabs 1 # and an input reference current phase # imgabs 2 #, and the technical problems that in an existing modulation method of the AC-DC matrix converter, the modulation parameters are too many, all the parameters are difficult to coordinate through closed-loop control, no parameter can be used for closed-loop control, and meanwhile coordination control over the primary side and the secondary side is difficult to achieve are solved. On the basis, the waveform of a switching signal of the grid-side 3-1MC matrix converter is improved, so that during voltage commutation and current commutation of the grid-side 3-1MC matrix converter, power switch tubes connected in parallel with body diodes with opposite current directions in the grid-side 3-1MC matrix converter are kept on, and the soft switching characteristic of the power switch tubes is realized.

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.

The invention discloses a power angle active control-based fault recovery overcurrent suppression method for a network construction converter, and belongs to the technical field of power electronic control. The method comprises the following steps: acquiring a power actual value and a power reference value of the network construction converter in real time, and acquiring a power error value; performing amplitude limiting with the upper limit value being 0 on the power error value to obtain an amplitude limiting result; multiplying the obtained amplitude limiting result by a proportional gain coefficient to obtain an adjustment value of a phase angle after the fault is cleared; and obtaining an original phase angle value generated in an active power control loop of the network construction converter, adding the adjustment value and the original phase angle value to obtain an actual phase angle value of the network construction converter, and performing closed-loop control and space vector modulation of the network construction converter by using the actual phase angle value to obtain the network construction converter. And completing fault recovery over-current suppression of the network construction converter. According to the invention, the original control architecture of the network construction converter is reserved, and the overcurrent problem in the fault recovery stage is effectively suppressed while the transient voltage source output capability of the network construction converter is maintained.

The invention discloses a current-limiting control method based on a network-forming static var generator. The current-limiting control method comprises the following steps: inputting an external direct-current voltage, stabilizing the voltage by a capacitor, and then outputting the voltage to an inverter bridge; the inverter bridge generates controllable alternating current through space vector modulation; the inductive filter filters high-frequency harmonic output end voltage; the terminal voltage amplitude and phase are monitored in real time, and current-limiting control is triggered based on the phase deviation between the voltage and the virtual internal potential when the voltage of the power grid drops; the terminal voltage interacts with ideal power grid voltage at a common coupling point through power grid impedance to generate PCC voltage; pCC voltage and output current are detected, and instantaneous power is calculated; the power signal is filtered and de-noised and then a modulation instruction is generated by the current-limiting controller and is fed back to the inverter bridge to form a closed loop. The reactive power supporting voltage is injected preferentially, the voltage drop amplitude is remarkably reduced, the inertia damping supporting capacity of the system is enhanced, power grid fault recovery is accelerated, and meanwhile the voltage instability problem caused by a traditional current limiting strategy is avoided.

The invention relates to a space vector modulation method based on a single-phase parallel current source inverter, and the method comprises the following steps: 1, constructing a single-phase parallel current source inverter circuit, and dividing all current vectors of the single-phase parallel current source inverter according to different amplitudes of output current Iw; 2, analyzing the influence of the small-current vector redundant switching state on the direct current, and constructing a small-current vector switching state selection strategy; 3, analyzing the influence of the zero-current vector redundant switching state on the direct current, and constructing a zero-current vector switching state selection strategy; and step 4, in each sampling period, synthesizing a reference current vector Iref by two static current vectors which are closest to each other according to an ampere-second balance principle, collecting a power grid voltage us and direct currents i1-i4 at the same time, and selecting a redundant switch state according to the strategies in the step 2 and the step 3 to realize the current balance of the direct current bridge arm. According to the invention, the waveform quality of the grid-connected current can be improved.

This invention relates to the field of inverter technology, and particularly to a heterogeneous power device hybrid inverter and its space vector modulation method. The heterogeneous power device hybrid inverter provided in this invention includes a first constant current source, a second constant current source, a main power inverter module, a secondary power inverter module, and a capacitive reactance module. The first constant current source is connected to the main power inverter module to provide current to the main power inverter module. The main power inverter module includes multiple silicon-based insulated-gate bipolar transistors (SBMTs) as main switching transistors, and the main power inverter module is connected to the capacitive reactance module. The second constant current source is connected to the secondary power inverter module to provide current to the secondary power inverter module. The secondary power inverter module includes multiple silicon carbide-based metal-oxide-semiconductor field-effect transistors (MOSFETs) as secondary switching transistors, and the secondary power inverter module is connected to the capacitive reactance module. The heterogeneous power device hybrid inverter and its space vector modulation method provided by this invention can balance high inverter frequency and low switching losses.