283 results about "Three phase inverter" patented technology

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 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 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 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.

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 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.

The invention discloses a new energy automobile power supply detection method and system, and belongs to the technical field of power supply fault detection. The method comprises the following steps: acquiring three-phase voltage of a three-phase inverter, summing absolute values to obtain a three-phase composite signal, segmenting according to a period, dividing each frame into a left signal section and a right signal section, extracting a morphological feature vector to calculate a time domain morphological mismatch value, and constructing a time domain morphological mismatch matrix; fourier transform is carried out on the left signal segment and the right signal segment, a frequency domain form mismatch value is calculated based on the difference between the frequency gravity centers of the fundamental frequency and the non-fundamental frequency, and a frequency domain form mismatch matrix is formed; and further constructing a time domain and frequency domain form mismatch evolution matrix, processing the matrix by using a double-domain collaborative enhancement neural network, and finally outputting a power supply fault score. Through collaborative analysis of the time domain and frequency domain features and evolution matrix construction, the fault detection precision of the new energy automobile power supply is effectively improved.

The invention discloses a three-phase inverter few-sensor model prediction control method and device. The method comprises the following steps: acquiring voltage and current sample data based on a three-phase inverter model prediction control system; aiming at the sample data, constructing and training a neural network; and voltage and current signals are calculated by adopting a neural network, and model prediction control is implemented. According to the designed method, the number of sensors of the three-phase inverter model predictive control system is reduced, and the anti-interference performance of the system is improved.

A kind of multi-line power quality treatment and power flow transfer device and control method, the device includes first regulating module, second regulating module and shared DC bus, first regulating module and second regulating module present upper and lower symmetrical structure;Two regulating module structures are same, and all are three-winding transformer primary winding and medium voltage AC bus connection, the first secondary winding of three-winding transformer is connected with first load through the secondary winding of first series transformer connected in series, the primary winding of first series transformer is connected with the AC end of first three-phase inverter;The AC end of three-phase rectifier is connected with the secondary winding of three-winding transformer;Medium voltage AC bus is connected with second load through the secondary winding of second series transformer connected in series, the primary winding of second series transformer is connected with the AC end of second three-phase inverter.The present application solves the increasingly complex power quality demand of decoupling regulation and mutual aid, multi-working condition in distribution network facing multi-feed line.

The application discloses a stability analysis method of a photovoltaic energy storage micro-grid in an islanding scenario based on system admittance characteristics, and belongs to the technical field of distributed new energy grid-connected power generation. The method comprises the following steps: determining the main circuit filter type and control structure of a three-phase inverter of a power generation unit; establishing a second-order admittance model of the inverter based on a harmonic linearization method; decoupling the second-order admittance model to obtain linear admittance models under positive and negative sequences; establishing the voltage-current relationship at a system point of common coupling based on a node voltage method according to the topological structure of the micro-grid, and obtaining a system admittance matrix; drawing the amplitude-frequency curve and the phase-frequency curve of key items in the system admittance matrix, determining the key characteristic frequency corresponding to the minimum point of the amplitude-frequency curve, and determining the stability of the system according to the positive and negative of the slope of the phase-frequency curve at the key characteristic frequency. The method can accurately analyze the stability of the photovoltaic energy storage micro-grid in the islanding operation scenario.

This invention discloses a dual-variable symmetrical injection modulation method for a two-phase permanent magnet synchronous motor, belonging to the field of motor drive and control technology. The method includes the following steps: S1, setting motor start-up logic and soft-start parameters; S2, generating two-phase orthogonal line voltage commands; S3, dual-variable symmetrical injection; S4, PWM comparator register mapping and output; S5, periodic execution. This method requires no modification to the hardware topology of a standard three-phase voltage source inverter or the addition of additional circuit components, and can be directly deployed on existing mature hardware platforms. This allows the same three-phase inverter to be used to drive both three-phase and two-phase motors, achieving hardware platform reuse and standardization, significantly reducing system development and bill of materials costs, resulting in low hardware cost and strong versatility.

This power conversion device (100) supplies power to a three-phase motor (11) that drives a compressor (10) for compressing a refrigerant. The power conversion device (100) includes: a three-phase inverter (102) having at least six semiconductor switches; and an inverter control unit (102a). The three-phase inverter (102) has a U-phase leg (102U), a V-phase leg (102V), and a W-phase leg (102W). When preheating the refrigerant, the inverter control unit (102a) selects two legs from among the U-phase leg (102U), the V-phase leg (102V), and the W-phase leg (102W). The inverter control unit (102a) carries out control to turn a positive-electrode-side semiconductor switch of a first leg and a negative-electrode-side semiconductor switch of a second leg on and off at the same timings, carries out control to turn a negative-electrode-side semiconductor switch of the first leg and a positive-electrode-side semiconductor switch of the second leg on and off at the same timings, and keeps a positive-electrode-side semiconductor switch and a negative-electrode-side semiconductor switch of a third leg turned off.

Embodiments of the present disclosure relate to circuitry for a three-phase inverter unit, a method for diagnosing a connection state of a three-phase inverter unit, a machine-readable storage medium, a computer program product, and a three-phase inverter. A three-phase inverter unit is connected between the power battery and the electric machine and includes three phases connected to the electric machine. The circuitry includes a diagnostic circuit configured to be connected to a respective phase of three phases; and a controllable power supply circuit configured to be connected to the diagnostic circuit to supply power to the diagnostic circuit, where the diagnostic circuit is further configured to receive different input voltages from respective phases in different connection states of the three phases, and output different output voltages corresponding to the different connection states. According to the circuit system disclosed by the embodiment of the invention, different connection states of three phases of the three-phase inverter unit can be diagnosed by diagnosing different output voltages of the circuit.

This invention relates to a low-current harmonic direct torque control method for a dual three-phase permanent magnet synchronous motor (PMSM), belonging to the field of PMSM control technology. The method is as follows: S1: Establish mathematical models of the fundamental and harmonic subspaces of the dual three-phase PMSM under vector space decoupling, and clarify the voltage vector distribution characteristics of the two subspaces; S2: In the fundamental subspace, design a duty cycle modulation strategy based on the principle of minimizing the error vector, and an improved deadbeat flux linkage torque controller; S3: In the harmonic subspace, design an online learning harmonic canceller, using the least mean square algorithm to update the weight coefficients in real time; S4: Select the D1 vector set as the effective vector of the harmonic subspace and perform sector division; S5: Add the effective voltage vector action time of the fundamental and harmonic subspaces to generate the final switching sequence, which is output to the dual three-phase inverter to effectively suppress torque ripple and harmonic current of the dual three-phase PMSM.

The present application relates to a discontinuous pulse width modulation method and to a three-phase inverter modulation circuit, wherein the discontinuous pulse width modulation method, on one hand, reduces the number of switching actions relative to a traditional SVPWM method, thereby reducing power consumption and improving the working efficiency of the inverter, and on the other hand, greatly increases stability relative to a traditional DPWM method, is capable of stable operation even with a continuously changing modulation ratio, and incorporates two advantages in low power consumption and high stability, the width modulation method provided by the present application likewise does not need to switch between different modulation modes.