347 results about "Three phase inverter" patented technology

The invention provides a three-phase inverter direct current side electric leakage fault type discrimination method and electronic equipment, and the method comprises the steps: carrying out the frequency spectrum time sequence characteristic analysis of the residual current of the alternating current side of a three-phase inverter, and analyzing the change of the amplitude of the residual current along with the time under different frequencies; the fault type of the direct current side electric leakage of the inverter can be known; by performing continuous energy monitoring on the residual current signal of the inverter, real-time current monitoring on the inverter is realized, and sudden change of the fault type of electric leakage or instantaneous electric leakage can be well monitored and distinguished. Aiming at the specific characteristics of the harmonic component of the leakage current of the inverter, different frequency spectrum characteristics of the leakage current under different fault types are determined, the electric leakage fault type discrimination method based on harmonic time-frequency characteristic extraction is provided on the basis, the specific fault type of the inverter can be discriminated under various working conditions, the position of the electric leakage fault is further positioned, and the reliability of the inverter is improved. The problem of inaccurate electric leakage fault type judgment and positioning in the current engineering application is solved.

The invention discloses a modeling method of a fractional order LC type three-phase inverter, and relates to the technical field of modeling and control of power electronic converters. On the basis of a traditional integer order LC type three-phase inverter, an integer order LC type filter in the inverter is replaced by a fractional order LC type filter, so that a new fractional order inverter topology is constructed. On the basis of the topology, mathematical models under a three-phase static abc coordinate system and a two-phase rotating dq coordinate system are constructed. Based on the mathematical model, a voltage and current double-closed-loop decoupling control strategy of the fractional order LC type three-phase inverter is deduced. In addition, a traditional virtual synchronous generator control link is replaced by an FOVSG control link, and the stability of the FOVSG control link is analyzed through a small signal model. According to the invention, dynamic decoupling can be effectively realized according to the order of the fractional order LC filter. In addition, an adjustable order is introduced in the FOVSG control link, and the performance of the inverter is improved under different control requirements.

The invention discloses a multi-line electric energy quality management and power flow transfer device and a control method, the device comprises a first regulation and control module, a second regulation and control module and a shared direct current bus, and the first regulation and control module and the second regulation and control module are of a vertically symmetrical structure; the two regulation and control modules are the same in structure, a primary winding of a three-winding transformer is connected with a medium-voltage alternating-current bus, a wire outlet end of a first secondary winding of the three-winding transformer is connected with a first load through a secondary winding of a first series transformer which is connected in series, and a primary winding of the first series transformer is connected with an alternating-current end of a first three-phase inverter; a wire outlet end of a second secondary winding of the three-winding transformer is connected with an alternating current end of the three-phase rectifier; the medium-voltage alternating-current bus is connected with a second load through a secondary winding of a second series transformer which is connected in series, and a primary winding of the second series transformer is connected with the alternating-current end of the second three-phase inverter. According to the invention, the increasingly complicated power quality requirements under multiple working conditions in the power distribution network facing multi-feeder decoupling regulation and control and mutual assistance are met.

The invention discloses a balance bridge arm control method and device of a three-phase inverter. The balance bridge arm control method comprises the following steps: acquiring an upper bus voltage, a lower bus voltage and an actual current of an inductor in real time; calculating a voltage difference value between the upper bus voltage and the lower bus voltage, and performing low-pass filtering processing on the voltage difference value; determining capacitance current of an upper bus capacitor and / or a lower bus capacitor according to the upper bus voltage and / or the lower bus voltage, and performing low-pass filtering processing on the capacitance current; calculating the reference current of the inductor according to the voltage difference value after the low-pass filtering processing and the capacitance current after the low-pass filtering processing; and controlling two switch tubes of the balance bridge arm according to the actual current and the reference current of the inductor. According to the technical scheme, the balance bridge arm can control potential balance of the neutral point of the direct-current bus and can restrain voltage ripples of a bus capacitor.

The invention relates to the technical field of new energy grid connection, in particular to a new energy grid-connected inverter system based on a double-stator synchronous motor interface, which comprises a three-phase inverter and a double-stator synchronous motor, the double-stator synchronous motor comprises a first stator, a rotor and a second stator. Planar air gaps exist between the rotor and the first stator and between the rotor and the second stator. The rotor comprises a first rotor and a second rotor which are rigidly connected, the first rotor is axially adjacent to the first stator, the second rotor is axially adjacent to the second stator, and a magnetic isolation ring is arranged between the first rotor and the second rotor; each of the first stator and the second stator comprises a stator core and an armature winding, the first rotor comprises a first rotor core, an excitation winding and a starting winding, and the second rotor comprises a second rotor core and a permanent magnet. According to the invention, the double-stator configuration can realize voltage transformation and frequency conversion functions, and can solve the problems of reduced power grid inertia, insufficient short-circuit capacity, aggravated broadband oscillation risk and the like caused by grid connection of large-scale new energy through power electronic equipment.

The invention discloses a topology circuit of an isolated single-phase integrated vehicle-mounted charging system for an electric vehicle and a control method of the topology circuit. The topology circuit comprises an open-winding permanent magnet synchronous motor, a dual three-phase inverter, a power battery pack, a bus capacitor, a high-frequency transformer, a winding change-over switch K1, a winding change-over switch K2 and a bus change-over switch G1, through switching of the winding change-over switch K1, the winding change-over switch K2 and the bus change-over switch G1, the system works in a driving mode or a charging mode, and the system is controlled in combination with a driving control method and a charging control method. According to the invention, electrical isolation of the integrated vehicle-mounted charging system is realized without adding extra power devices and industrial frequency transformers, and the reliability and safety of charging are improved.

The invention discloses a permanent magnet synchronous motor multi-resistor current sampling method and a motor control system. The permanent magnet synchronous motor controls a three-phase inverter based on an SVPWM strategy, and successively samples two phases to be sampled in each control period. The sampling method comprises the following steps: judging whether a sampling window of a to-be-sampled short phase is smaller than first minimum sampling time or not; if yes, prolonging the conduction time of the short-phase lower bridge arm to the first minimum sampling time, and enabling the direction of the voltage synthesis vector obtained after prolonging to be unchanged; judging whether the sampling window of the to-be-sampled long phase is smaller than second minimum sampling time or not; if yes, the conduction time of the long-phase lower bridge arm is shifted rightwards; and successively collecting short-phase current and long-phase current in the current control period, and calculating three-phase current according to the short-phase current and the long-phase current. The maximum duty ratio of the upper bridge arm of the to-be-sampled two phases can be increased as much as possible by scaling and adjusting the proportion of the first sampled short phase and combining with the PWM waveform phase shift of the second sampled long phase, so that the maximum output capability of the motor is improved.

The invention discloses a grid-connected three-phase LCL inverter parameter monitoring method for digital twinning modeling. The method comprises the following steps: acquiring actual measurement data of a grid-connected three-phase LCL inverter; and according to actual measurement data, performing iterative optimization on monitoring parameter sets of a digital twin model of the grid-connected three-phase LCL inverter based on an adaptive particle swarm algorithm, including: operating the digital twin model under each monitoring parameter set to obtain corresponding multiple groups of model output data, and calculating a corresponding error objective function, taking the monitoring parameter set corresponding to the minimum target function value as an optimal monitoring parameter set; if an error objective function value responding to the optimal monitoring parameter set is smaller than a function threshold value, outputting the error objective function value as a final optimal monitoring parameter set, and performing subsequent parameter monitoring; and otherwise, iteration optimization is continued. And high-precision calibration of the digital twin model and the real inverter is realized, so that key parameters which are difficult to directly measure or high in measurement cost in the real inverter are calculated in real time.

The invention discloses a novel high-frequency three-phase H-bridge inversion parallel re-topology and a modulation method thereof, each phase in a three-phase inverter adopts one or more parallel single-phase full-bridge topologies, and each single-phase full-bridge topology comprises a direct-current bus part, an MOS module part, a differential-mode inductor part and a common-mode rejection part; the direct current bus part is a bus capacitor plate, the MOS module part is a full-bridge circuit, the differential mode inductor part comprises two differential mode inductors, and the common mode rejection part comprises a common mode inductor. A unipolar frequency doubling and carrier phase shift PWM (Pulse Width Modulation) mode is adopted, each full-bridge topology adopts unipolar frequency doubling modulation, modulation wave phase shift modulation is adopted between the full-bridge topologies, the phase difference is 360 / N, and N is the number of full-bridge circuits connected in parallel. According to the scheme, the purpose of increasing the output power, the switching frequency and the level number can be achieved.

The invention provides a motor protection circuit, a motor power supply system and electronic equipment, and belongs to the technical field of electronics. The motor protection circuit comprises an on-off control circuit; the on-off control circuit is connected with a three-phase inverter and a motor, and is used for disconnecting at least two phase current output ends of the three-phase inverter and the motor under the condition that the three-phase inverter has a control fault, so that an electrical connection loop does not exist between the three-phase inverter and the motor. The back electromotive force current generated by the motor due to the back electromotive force is effectively prevented from recharging through the three-phase inverter, and the problem that the three-phase inverter, the battery pack and other devices connected with the motor are damaged due to the back electromotive force current is solved.

The invention provides a virtual inertia adaptive control method, device and system, and relates to the technical field of inverter system control. The method comprises the following steps: calculating a reference current value according to a power reference value and an actual output voltage; calculating a current deviation value according to the reference current value and the actual output current value; outputting the current deviation value to an adaptive resonance controller to obtain a compensation control voltage signal; inputting the compensation control signal to an AHO virtual oscillator to obtain a reference value of the output voltage of the inverter; and controlling the output of the three-phase inverter circuit according to the reference value of the inverter output voltage. Wherein the adaptive resonance controller carries out adaptive control through the proportional parameter and the proportional resonance inertial parameter. The virtual inertia output can be dynamically adjusted according to the real-time requirement of the system, the overshoot phenomenon caused by power oscillation is effectively suppressed while the frequency stability is met, and the capacity of the system for resisting sudden load change and frequency disturbance is enhanced.

The utility model relates to the field of photovoltaic power generation energy management technology, in particular to an energy management system for a household photovoltaic power station, which comprises a distribution box with a built-in household load; the three-phase inverter is connected to the distribution box, and the three-phase inverter is connected in series with a photovoltaic module and converts direct current generated by the photovoltaic module into alternating current; an energy gateway which is connected with the distribution box and monitors the real-time electric quantity input of the photovoltaic module; and the load controller is connected to the distribution box, and the load controller is connected with an electric load and adjusts the power of the electric load. According to the invention, the zero-feed network construction of the household photovoltaic power station is realized, and the utilization rate of photovoltaic power generation is improved.

The invention relates to a three-phase power dynamic distribution method, a three-phase inverter and a control unit for the three-phase inverter. The method comprises the following steps: S1, obtaining an inversion power parameter value of each phase, obtaining an electric meter power parameter value of each phase, and obtaining a rated power parameter value of the inverter; s2, calculating the overload power of each phase according to the inverter power parameter value, the ammeter power parameter value and the rated power parameter value, and then generating the overload state of each phase according to the overload power of each phase; and S3, according to the inversion power parameter value of each phase, the rated power parameter value of the inverter and the overload state of each phase, obtaining the power amplitude limiting value of the current overload state. According to the scheme provided by the invention, the distribution result with lower overload power and higher power balance degree of each phase is calculated on the premise of meeting the maximum utilization of the power, and the negative influence caused by long-term overload of a certain phase can be remarkably reduced.

The invention discloses a permanent magnet synchronous motor nonlinear integral compound control method based on a novel reaching law. The method comprises the following steps: detecting a motor rotating speed omega and position angle information theta; calculating a rotating speed deviation e; transforming to obtain id and iq; calculating a nonlinear integral sliding mode surface s and a novel reaching law to observe a motor rotating speed omega and a load torque TL; calculating an output current given value iq *; performing Park inverse transformation to obtain u alpha and u beta; and performing voltage space vector pulse width modulation to obtain three switching signals of a three-phase inverter, and controlling the permanent magnet synchronous motor. According to the permanent magnet synchronous motor control method, the load disturbance observer and the nonlinear integral sliding mode controller are combined to construct the novel composite sliding mode controller, unknown disturbance can be estimated and compensated timely and accurately, the degree of dependence on high gain is effectively reduced, and the robustness of dealing with the unknown disturbance is remarkably improved.

A three-phase wireless electric energy transmission device disclosed by the present invention comprises a three-phase inverter, a three-phase switch capacitor, a coil magnetic field coupling structure and a rectifier, the coil magnetic field coupling structure comprises a primary coil and a secondary coil which are arranged in mirror symmetry, the primary coil is provided with two layers, each layer comprises a three-phase coil, each phase coil occupies a 120-degree angle range of the circumference, and the rectifier is connected with the primary coil and the secondary coil. The two layers of coils form a staggered angle, each phase of switched capacitor of the three-phase switched capacitor comprises a first capacitor branch and a second capacitor branch which are arranged in parallel, the first capacitor branch is provided with a first capacitor, and the second capacitor branch comprises a second capacitor and a switch module which are arranged in series; the switch module adjusts the equivalent capacitance value of the second capacitor branch through the duty ratio and adjusts the transmission power of the three-phase wireless power transmission device. The invention further discloses a load power adjusting method of the three-phase wireless power transmission device, the transmission efficiency can be kept unchanged within the adjusting range, and soft switching can be achieved within the adjusting range.

The invention discloses an island detection method and device for a three-phase inverter grid-connected system, and belongs to the technical field of island detection. The method comprises the following steps: applying reactive disturbance current to reactive target current of an inverter; wherein the reactive disturbance current periodically changes at the disturbance frequency; obtaining frequency information of the three-phase voltage of the common connection point, and extracting a disturbance component periodically changing by a disturbance frequency in the frequency information; calculating an accumulated value of the absolute value of the disturbance component in a sliding time window with a preset duration, and taking the accumulated value as an island characteristic quantity; wherein the window trailing edge of the sliding time window is the current moment, and the preset duration is greater than or equal to a disturbance period corresponding to the disturbance frequency; and when the island characteristic quantity is greater than a preset threshold value, determining that island operation occurs. The embodiment of the invention provides a universal detection method suitable for identification of various islands, and comprehensive identification of the operation condition of the islands can be realized.

The invention discloses a permanent magnet motor direct torque control method and system based on model prediction and a medium, and belongs to the technical field of permanent magnet synchronous motor control. According to the permanent magnet synchronous motor direct torque control method based on model prediction, two-phase current of a permanent magnet synchronous motor is processed by constructing a Clarke transformation model, a flux linkage and torque model, a voltage vector optimization model, a switching time calculation model, a cost function minimization model and a three-phase inverter control model, a space voltage vector is determined, and the direct torque of the permanent magnet synchronous motor is obtained. And switching action information of a switching tube is obtained and is used for controlling bus voltage to be input into the permanent magnet synchronous motor, so that the permanent magnet synchronous motor is driven, and direct torque control of the permanent magnet synchronous motor based on model prediction is completed, and therefore, the switching state of a switch can be controlled to be optimal, and torque pulsation is effectively reduced; therefore, the system operation efficiency is effectively improved, the system stability is improved, the switching loss is reduced, and the scheme is scientific, reasonable and feasible.

The invention belongs to the technical field of power electronics, and particularly relates to a model prediction control method and a T-type three-level three-phase inverter device thereof. The invention provides a model prediction current amplitude limiting control method for a T-type three-level three-phase inverter under an unbalanced power grid based on four-vector synthesis space vector pulse width modulation. A reference voltage is obtained through model prediction, after the reference voltage is obtained, based on a space vector pulse width modulation strategy, a vector synthesis mode is adopted, a voltage vector is divided into 36 sectors according to different switching states, a switching state corresponding to the generated reference voltage is obtained through a four-vector synthesis mode, and a fixed switching frequency is obtained; and a multi-target cost function is established according to a reference voltage and a direct-current side capacitor voltage difference, a resultant vector is symmetrically distributed through a time inverse proportion function, finally, the output current of the inverter is controlled to be kept at a low harmonic distortion rate under balanced and unbalanced working conditions and is effectively limited within a specified range, and meanwhile, the direct-current side neutral-point potential is kept balanced.

The invention discloses a split-phase anti-countercurrent control method and system for a three-phase inverter. The method comprises the following steps: acquiring output power, load power and grid-connected power of each phase of the three-phase inverter in real time; for each phase, calculating the difference between the load power and the output power, if the difference is less than or equal to 0, judging that the phase has countercurrent, and performing corresponding split-phase control; and if the difference is greater than 0, judging that the phase has a countercurrent trend, and carrying out corresponding split-phase control.

The invention relates to the technical field of motor control, in particular to a three-phase brushless direct-current fan control system based on an MCU and an FOC, which comprises a sampling module, an MCU control module, a PWM driving module, an interruption module and a control protection module, and is characterized in that the sampling module is used for converting an analog signal into a digital signal and inputting the digital signal into the MCU control module; the MCU control module is used for executing an FOC algorithm to generate PWM waves; the PWM driving module is used for controlling the three-phase inverter according to the generated PWM waves; the interrupt module is used for realizing main algorithm execution operation and state machine switching of the MCU control module; and the control protection module is used for monitoring the state of the control system in real time and executing corresponding protection measures when a fault occurs. Therefore, the problems that an existing control system is large in torque pulsation, high in noise and low in efficiency, and an existing FOC technology is high in cost, large in resource occupation and the like are solved.

A rechargeable battery device for providing three-phase alternating current independently of location is achieved. It comprises a housing providing for a three-phase alternating current output. One or more rechargeable battery packs, at least one bidirectional three-phase inverter as well as one or more common mode filters are accommodated in the housing. The housing incorporates one or more heatsinks with a heat-dissipating surface. The energy density of the rechargeable battery device corresponding to the gross capacity of the one or more rechargeable battery packs in relation to the residual weight of the rechargeable battery device is at least 0.1 kWh / kg, wherein the residual weight corresponds to a total weight of the rechargeable battery device minus a weight of the one or more rechargeable battery packs.

The invention belongs to the technical field of inverters, and mainly provides a three-phase inverter midpoint potential control method and device based on a feed-forward neural network, in the embodiment of the invention, real-time characteristic parameters of a three-phase inverter are obtained, and the real-time characteristic parameters are input into a target feed-forward neural network model obtained through pre-training, so that the midpoint potential of the three-phase inverter is controlled. The method comprises the following steps: firstly, obtaining a midpoint potential offset predicted value output by a target feedforward neural network model, then adjusting a modulation parameter of SVPWM modulation according to the midpoint potential offset predicted value, and finally, outputting a PWM signal for controlling an inverter switching device based on the adjusted modulation parameter to drive a three-phase inverter. The active balance of the neutral-point potential of the three-phase inverter bus based on the feedforward neural network and combined with SVPWM modulation is realized, and the technical problems that the neutral-point potential of the three-phase inverter bus is unbalanced and easy to deviate are solved.

An exemplary Cascaded H-bridge or Modular Multilevel Converter / Inverter are disclosed that employ a H-bridge cell or half-bridge cell that includes a linking switch additionally employed between two H-bridge cells, i cell and i+1 cell, to allow a parallel number of cells to operate together. Each of the H-bridge cells includes the standard four switches and additionally the linking switch between two H-bridge cells. The system can beneficially have improved system conversion efficiency due to better DC energy source utilizations, e.g., for improved efficiency of converters that convert DC energy to AC energy. The cascading H-bridge cells (or half-bridge cells) can be configured as a charge pump converter, bidirectional 3-phase inverter, among other topologies.

A power converter configured to supply power from one of an AC power grid or an energy storage device to an air conditioning system, the power converter including a positive DC line and a negative DC line; a first leg extending between the positive DC line and the negative DC line, the first leg including a first switch and a second switch; a second leg extending between the positive DC line and the negative DC line, the second leg including a third switch and a fourth switch; a third leg extending between the positive DC line and the negative DC line, the third leg including a fifth switch and a sixth switch; wherein the first leg, second and third leg are part of a three-phase inverter package; the AC power grid connected to a junction between the third switch and the fourth switch; and a controller.

The invention relates to the technical field of power electronics, in particular to a rapid modeling method and system for a direct-current micro-grid converter, and the method comprises the steps: carrying out the harmonic component fitting of a switching function of a discontinuous converter based on the Fourier series in a triangular form, and generating a fitting switching model; according to the fitting switch model, obtaining a photovoltaic improved time domain model by using a maximum power point tracking algorithm; utilizing the fitting switch model to construct an energy storage improved time domain model; a bipolar switching function is defined according to the three-phase inverter circuit topology, and an inverter improved time domain model is obtained based on the bipolar switching function; and integrating the photovoltaic improved time-domain model, the energy storage improved time-domain model and the inverter improved time-domain model into a DC micro-grid architecture, and constructing an optical storage DC micro-grid joint simulation model. According to the method, the switching function of the discontinuous converter is fitted through the Fourier series based on the triangular form, so that rapid and accurate modeling of the DC micro-grid converter is realized, and technical support is provided for safe and stable operation of the micro-grid.

The invention discloses a controllable three-phase AC power capacitor reliability test circuit, method and system, and the circuit comprises a first DC voltage source, a second DC voltage source, a three-phase inverter, a first transformer, a second transformer, a third transformer, a first inductor, a second inductor, and a third inductor. The output end of the first DC voltage source is connected with the input end of the three-phase inverter, and the three-phase inverter is connected with the first end of the first to-be-tested capacitor, the first end of the second to-be-tested capacitor and the first end of the third to-be-tested capacitor through the first transformer, the second transformer and the third transformer. The second ends of the first to-be-measured capacitor, the second to-be-measured capacitor and the third to-be-measured capacitor are connected to the positive electrode of the second direct-current voltage source through the first inductor, the second inductor and the third inductor respectively, and the negative electrode of the second direct-current voltage source is connected with the negative electrode of the first direct-current voltage source. The method is low in cost, low in energy consumption and convenient to control.

This inverter control device: switches, in each carrier cycle, the state of a three-phase inverter among four kinds of use vectors such that the number of switching times is minimized; switches one basic space vector included in the four kinds of use vectors to a different basic space vector every 60-degree electrical angle; and switches a zero vector, which is used at the first timing of each carrier cycle, between two kinds of zero vectors every 60-degree electrical angle. When six electrical angles per one cycle of the inverter at the time of basic space vector switching are regarded as 0, 60, 120, 180, 240, and 300 degrees, six electrical angles per one cycle of the inverter at the time of zero vector switching become the angles obtained by adding, to the six electrical angles at the time of the basic space vector switching, the same prescribed angle of not less than 15 degrees but less than 45 degrees.

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 provides a control method and system of a single-stage isolation resonance type three-phase inverter. The control method comprises the following steps: dividing a power frequency period into a plurality of intervals; in each interval, a complete power transmission period is divided into a plurality of independent switching periods, and each switching period is divided into a plurality of stages through a direct current side voltage vihf and an alternating current side voltage vohf; carrying out Fourier decomposition on the voltage at the two ends of the resonant cavity in each switching period to obtain a fundamental component, calculating an expression of transmission power through a vector analysis method, and designing resonance parameters and switching frequency according to system requirements; and determining modulation signals of the direct current side and the alternating current side in each switching period based on the square wave duty ratio of the direct current side, the external phase shift angle of the alternating current and direct current side, the power factor angle of the alternating current side and the voltage phase. According to the invention, decoupling control of active power and reactive power at the AC side can be realized, and the control complexity of the system is reduced; accurate control of active power and reactive power of the AC side is realized, and the four-quadrant operation capability of the system is improved.

The invention discloses a three-phase inverter open-circuit fault diagnosis method based on deep transfer learning. The three-phase inverter open-circuit fault diagnosis method comprises the following steps: step 100, collecting a sample set 1 with a label in a source domain; collecting a sample set 2 with labels in the target domain and a sample set 3 without labels in the target domain; step 200, constructing a convolutional neural network model for fault diagnosis, and training the model by using a sample set 1 of a source domain to obtain a pre-training model alpha; step 300, constructing a fault diagnosis model based on transfer learning on the basis of the pre-training model alpha, and training the model by using a sample set 2 of a target domain to obtain a transfer model beta; step 400, using the migration model beta to predict unlabeled samples in the unlabeled sample set 3 to generate a pseudo label, and using a consistency regularization technology to smooth a pseudo label prediction result for subsequent training of the migration model beta to obtain a final optimization model gamma; and step 500, inputting to-be-detected three-phase inverter data into the model gamma, and outputting a predicted health state. Through the method, the problem of insufficient target domain samples is solved, and the diagnosis accuracy is improved.