83 results about "Power electronics converters" patented technology

The application discloses a kind of three-phase rectifier multiple switch tube open-circuit fault diagnosis methods based on voltage deviation, belong to power electronic converter fault diagnosis technical field.Method includes: obtaining relevant signal for diagnosis;According to three-phase voltage, three-phase current, three-phase inductance value, three-phase equivalent resistance value and switching period, the actual value of three-phase line voltage is calculated;According to DC voltage and the duty cycle of switch tube on three-phase bridge arm, the expected value of three-phase line voltage is calculated;Difference is obtained between the expected value and actual value of three-phase line voltage;The deviation value of three-phase line voltage is compared with first preset threshold and second preset threshold, to determine the polarity of the deviation value of three-phase line voltage;Wherein, first preset threshold is less than second preset threshold;The polarity of the deviation value of three-phase line voltage is combined with voltage phase, to determine fault switch tube.The application can quickly diagnose for various situations of multiple switch tube fault, including single switch fault, two switch tubes in succession fault, two switch tubes simultaneous fault.

This invention discloses a data-driven intelligent operation and maintenance method for vehicle-to-grid (V2G-Vehicle-Storage) systems. The method collects real-time operating status data of heterogeneous power electronic converters and performs data preprocessing. Based on the preprocessed data, standardized input is generated and fed into a pre-built and trained fault identification model based on a convolutional neural network, outputting fault type identification results. Based on the fault type identification results, fault classification, fault item confirmation, fault cause analysis, and automatic generation of fault handling solutions are performed. This invention's technical solution optimizes the problems of lagging operation and maintenance diagnosis and high false alarm rates under current conditions through deep learning algorithms, realizing a data-driven end-to-end process of system fault diagnosis, location, analysis, and operation and maintenance, ensuring the safe operation of the system.

The application relates to the technical field of power electronic converter control, and provides a three-port flyback DC-AC converter, characterized in that the three-port flyback DC-AC converter comprises a flyback circuit, a power frequency reverse bridge, an AC-DC converter and a CL filter which are sequentially connected in cascade; the AC-DC converter is an AC-DC three-winding flyback converter which can realize power factor correction function, and is realized through active device multiplexing and magnetic component multiplexing, and comprises a flyback transformer T 2, excitation inductance L f , output switch Q 3, Q 4; the modulation method is to calculate instantaneous output power P o , judge the operation mode of the system, and respectively perform active modulation, reactive modulation or mixed modulation, so that the power factor is adjusted through the modulation method.

The application discloses a kind of adaptive compensation method and related device for three-phase current imbalance and harmonic, belong to power system technical field;The method is based on the instantaneous reactive power theory and the quick separation and instruction generation of fundamental wave positive sequence component and unbalance compensation component of sliding discrete fourier transform;Multi-objective model predictive current control with embedded repeated learning correction mechanism to achieve high-precision tracking of compensation current instruction and system circulation suppression;Multi-objective weight factor online dynamic adjustment mechanism based on fuzzy reasoning, according to the adaptive balance between the control emphasis of tracking accuracy, circulation suppression and switching loss according to the real-time operating state of the system;And, adaptive closed-loop management architecture based on the above module cooperation, drive active power electronic converter to generate compensation current, realize the comprehensive management of three-phase imbalance and harmonic and global optimization of system performance.

The application discloses a modulation and power balance method of a hybrid cascaded H-bridge inverter and an extended topology system, belongs to the technical field of power electronic converters, and core comprises the following steps: constructing a thirteen-level basic topology with a DC side voltage ratio of 1:1:2:2, which is cascaded by two low-voltage H-bridge units and two high-voltage H-bridge units; adopting a hybrid modulation strategy, the high-voltage unit works at a fundamental frequency by using a staircase wave modulation to reduce loss, and the low-voltage unit uses an improved carrier phase-shifted PWM modulation based on a reconstructed laminated triangular carrier to eliminate reverse circulating current and improve the equivalent switching frequency; the high-voltage unit driving signals are cyclically exchanged with 1 / 4 output voltage period as a rotation period, so that power self-balance is realized; and a general extended topology scheme is provided, which is cascaded by n high-voltage modules and k low-voltage modules, avoids level loss under the constraint of k≥m, and can use the modulation and power balance logic of the basic topology.

This invention relates to the field of power electronic converter control technology and discloses a method and apparatus for judging the transient stability of a hybrid system with a grid-connected converter. The method includes constructing an equivalent model of the hybrid system comprising a grid-connected converter and a network-connected converter, wherein a virtual impedance is connected in series in the branch of the network-connected converter; constructing a Lyapunov energy function based on the equivalent model, wherein the independent variables include the power angle and phase-locked loop frequency of the grid-connected converter, and the power angle, frequency, and voltage amplitude of the network-connected converter; determining the stability domain boundary of the hybrid system using the Lassel invariant set principle when the derivative of the energy function with respect to time is less than or equal to 0; calculating the critical range of the virtual impedance based on the changing trend of the stability domain boundary, and determining the target value of the virtual impedance to maintain the transient stability of the hybrid system. The above method achieves quantitative judgment and parameter tuning of the transient stability of the hybrid system.

The application discloses a wide input range high-gain three-port DC-DC converter, and belongs to the field of power electronic converters. The converter is provided with three ports of a fuel cell FC, a storage battery Bat and a resistance load R, the FC port to the Bat port is a four-switch Buck-Boost converter, the wide input range of the FC is realized, and a switch capacitor unit composed of a switch tube, a capacitor and a diode is combined, the on-off of the switch tube is controlled, the connection mode of the inductor and the capacitor in the circuit and the on-off state of the diode are changed, and therefore the voltage gain of the FC port to the R port and the Bat port to the R port is improved. The application has the advantages of wide input range, high voltage gain, high integration degree and high stability, and is suitable for a new energy hybrid power generation system of fuel cells, photovoltaic cells and the like.

The present invention pertains to a power electronic converter, such as an inverter or converter, for an electric application such as a motor drive, electrolyzer or charger. The power electronic converter includes a DC link and an active front end (AFE) connected to grid via a filter and a grid board with a first inrush relay with a resistive device. The resistive device may be a resistor, more specifically an NTC resistor or a PTC thermistor. The grid board further includes a second inrush relay, wherein at least one of the inrush relays is controlled to engage or disengage during startup phase of the power electronic converter and during abnormal grid voltage conditions, such that the DC link is charged via the resistive device or by bypassing the resistive device, and such that the AFE is provided for boosting the DC link voltage to a save level and under controlled conditions. The invention also pertains to an electric motor drive according and a method for operating a power electronic converter.

The application provides a DC voltage dynamic VSG frequency coupling impedance modeling and stability analysis method, and relates to the technical field of power electronic converter control. The method comprises the following steps: constructing a two-stage VSG system topology; establishing a front-stage DC voltage control model and a rear-stage VSG power control model; based on a harmonic linearization method, establishing a small-signal model considering the mirror frequency effect; deducing a conductance matrix and an impedance matrix containing a DC voltage coupling term; and verifying the system stability through a generalized Nyquist criterion and time domain simulation. The application fuses the DC voltage dynamic and the mirror frequency effect, accurately represents the frequency coupling characteristics of the VSG, avoids the calculation deviation of the traditional model, improves the stability analysis precision, is suitable for new energy power generation, AC / DC microgrid and other scenes, and has important engineering application value.

The application discloses an AC-AC converter and a control method thereof, and belongs to the technical field of power electronic converters. The application comprises the following steps: sampling a first AC power, the maximum amplitude of which is L phase, the second maximum amplitude of which is M phase, and the minimum amplitude of which is S phase; setting the switching frequency of a primary side conversion unit as a resonance frequency, setting the switching phase shift duty cycle of the primary side conversion unit according to the S phase voltage and the M phase voltage; and determining the switching drive logic of a secondary side conversion unit according to the switching drive logic of the primary side conversion unit. The application realizes the AC-AC conversion with high efficiency, high power density and bidirectional energy flow by means of easy-to-implement open-loop operation, and greatly reduces the complexity of control and sampling.

This invention discloses a method and system for arc suppression in distribution networks using distributed power electronic equipment in coordination. The method includes... n Distributed installation on the feeder of the distribution network i A power electronic device is connected to the medium-voltage side of the distribution network via a power electronic converter and then connected to the distribution network's ground loop via a zero-sequence channel. When the distribution network is in steady-state operation and there is a three-phase ground parameter imbalance, at least one power electronic device is controlled to output a compensation current into the distribution network. When a single-phase ground fault occurs, it will... i The power electronic equipment is grouped into a current support group and a voltage clamping unit, which switch to current arc suppression mode and voltage clamping mode respectively. When the single-phase ground fault disappears, the power electronic equipment exits the coordinated arc suppression mode and switches back to steady-state operation mode. This invention achieves stable and reliable suppression of arcs from single-phase ground faults.

This invention relates to the field of spacecraft power technology, and in particular to a space power system with controllable power flow and its control method. It includes a spacecraft primary bus, a power electronic converter with controllable power flow, an energy storage unit, a logic control unit, a load, and a power distribution switch. The positive terminal of the spacecraft primary bus is connected to one end of the power distribution switch and one input terminal of the power electronic converter with controllable power flow. One end of the load is connected to the other end of the power distribution switch. The other input terminal of the power electronic converter with controllable power flow is connected to the other end of the load and the negative terminal of the spacecraft primary bus. The input terminal of the energy storage unit is connected to the output terminal of the power electronic converter with controllable power flow. The logic control unit is used to collect the voltage at the positive and negative terminals of the spacecraft primary bus and the current of the load. This invention features high power density, fast dynamic response, simple circuit structure, and avoids severe electromagnetic interference.

This invention discloses a hybrid synchronization control method and system for a grid-connected energy storage converter that considers active power point tracking, belonging to the field of power electronic converter control technology. The method includes: determining a grid fault when the grid positive-sequence voltage exceeds the start-up threshold range; implementing voltage droop control for reactive power and calculating reactive power in real time; calculating a target reference value for active power based on voltage droop depth and reactive power priority support constraints; calculating a target value for AC q-axis capacitor voltage based on the target reference value for active power to adjust the output power; when the grid positive-sequence voltage recovers to the start-up threshold range, restoring the target reference value for active power to the pre-fault active power target value, and synchronously restoring the target value for AC q-axis capacitor voltage; during the recovery process, real-time tracking of the grid phase is achieved through output power until the grid stabilizes and hybrid synchronization control is completed. This invention accelerates phase angle tracking speed after voltage surges and improves transient stability.

The application relates to the technical field of power electronic converters, and discloses a heat dissipation device of a power electronic converter, which comprises a converter shell, a fan, an air outlet adjusting assembly, a temperature sensor and a controller; the converter shell is provided with a containing cavity for placing electronic components; the converter shell is provided with a heat dissipation opening and an air inlet opening which are communicated with the containing cavity; the fan is arranged on the outer side of the converter shell, and the blowing opening of the fan is communicated with the containing cavity through the air inlet opening; the air outlet adjusting assembly is arranged at the position where the heat dissipation opening is connected with the converter shell and is used for adjusting the opening degree of the heat dissipation opening; the temperature sensor is arranged in the containing cavity and is used for detecting the temperature and transmitting the temperature data to the controller; and the controller is electrically connected with the temperature sensor and the air outlet adjusting assembly and is used for controlling the air outlet adjusting assembly according to the temperature data. The heat dissipation device of the power electronic converter does not need to frequently switch the fan, can effectively maintain the internal temperature of the converter shell in a proper range, and prolongs the service life of the electronic components.

This invention relates to the field of power electronic converter technology, and discloses an asymmetric magnetic integrated transformer with multi-rail concurrent output and its design method. The structure includes a three-dimensional cross-shaped shared magnetic core and asymmetric spatially distributed windings. The design method of the magnetic integrated transformer includes: S1: designing the winding spatial layout based on the characteristics of multiple voltage rails with the same power; S2: extracting the full-order inductance matrix based on the unit current excitation condition; S3: deriving the analytical expression of the multi-port equivalent leakage inductance; S4: matching the multi-rail concurrent LLC resonant topology parameters. This invention improves the magnetic flux distribution under multi-port concurrent operation, suppresses local magnetic flux density concentration, and improves the space utilization and power density of magnetic components.

The application provides an auxiliary resonant converter pole inverter unit and method, which can be applied to the field of power electronic converters. The auxiliary resonant converter pole inverter unit comprises: a configuration configured to control the second main switch tube and the second auxiliary switch tube to be turned on, and the first main switch tube and the first auxiliary switch tube to be turned off in a first time period, so as to turn on a path passing through the second split capacitor, the turn-on channel of the second auxiliary switch tube, the parasitic diode of the first auxiliary switch tube, the resonant inductor, the turn-on channel of the second main switch tube, and returning to the second split capacitor, and a path passing through the positive electrode of the output voltage, the first split capacitor, the turn-on channel of the second auxiliary switch tube, the parasitic diode of the first auxiliary switch tube, the turn-on channel of the second main switch tube, and the negative electrode of the output voltage. By controlling the second auxiliary switch tube to be turned on when the second main switch tube maintains a turn-on state, the voltage deviation generated by the first split capacitor and the second split capacitor in operation is compensated, and the reliability is improved.

The application discloses a transient midpoint potential collaborative suppression method suitable for a network-constructed three-level T-type inverter and belongs to the technical field of power electronic converter control. In view of the problem that the three-level T-type inverter is prone to midpoint potential deviation in the process of grid frequency disturbance in a wind storage network-constructed scene, the application comprises the following steps: a low-frequency coupling model is established, in which active disturbance is transmitted to midpoint potential through d-axis current and midpoint current; event-triggered logic with hysteresis characteristics is constructed according to frequency deviation; a power shaping link is arranged at a source end, active instructions in an event window are subjected to second-order shaping, amplitude limiting and change rate constraint processing; a zero sequence extended state observer is arranged at a terminal side, online estimation is conducted on the generalized disturbance of a midpoint channel, and an additional compensation quantity is generated through a zero sequence port; and the source end power shaping and the terminal side zero sequence extended state observer are collaboratively put into the same event window, so that low-frequency disturbance entering the midpoint channel is weakened and the cumulative deviation of the midpoint potential is suppressed. The application can effectively reduce the midpoint potential peak value, suppress low-frequency energy accumulation, reduce transient peak current stress, and improve the operation safety and control stability of the network-constructed three-level converter under strong disturbance working conditions.

The application discloses a current sampling current compensation differential mode active EMI filter and system, and belongs to the field of active EMI filters, and comprises: an injection circuit, an input end of which is connected with a DC bus, and a connection point is located between a LISN and a bus support capacitor; a current limiting auxiliary inductor, which is connected in series on the DC bus and is located between the LISN and the bus support capacitor; a sampling circuit, which is used for sampling an EMI interference source current between the LISN and a bridge arm of a power electronic converter, and performing integral processing on a corresponding induced voltage to obtain a voltage signal; a signal processing circuit, which is used for eliminating a DC bias in the voltage signal and adjusting the voltage signal to be matched with a phase, so as to obtain an injection voltage; and a power amplification circuit, which is used for performing power amplification on the injection voltage to obtain an injection current, and the injection circuit is used for converting the injection current into an injection current matched with the phase, and injecting the injection current into the DC bus to realize DC side differential mode EMI suppression. The application can improve the insertion loss and improve the suppression effect of the DC side differential mode EMI.

This invention relates to a symmetrical voltage doubler type high-gain DC-DC boost converter, belonging to the technical field of power electronic converters. It solves the problem that traditional symmetrical converters cannot simultaneously achieve simple circuit structure, high boost capability, and electromagnetic interference immunity. This invention combines capacitors, diodes, and coupled inductors in a specific connection method of symmetrical interleaved parallel connection and magnetic integration to form an integrated, miniaturized high-gain conversion unit, balancing structural simplification and performance optimization. This invention is primarily applied in DC power conversion applications with high boost ratios.

The application provides a network configuration type control method of a static synchronous compensator, belongs to the field of power electronic converter control, and aims to solve the problems of large calculation coupling interference between a DC side voltage and a grid voltage angular frequency, insufficient inner voltage amplitude smoothness and insufficient flexible reactive power compensation in the existing network configuration type control of the static synchronous compensator. The control method core comprises an angular frequency calculation branch and an inner voltage amplitude calculation branch: the angular frequency calculation branch realizes fast and stable control of the DC side voltage through a fast proportional differential controller, and is matched with a decoupling control to reduce the coupling interference of the DC side voltage; the inner voltage amplitude calculation branch adopts a reactive power controller with droop characteristics and inertia characteristics, takes the grid connection point voltage as a feedback signal, dynamically adjusts the inner voltage amplitude of the static synchronous compensator to improve the smoothness, and thus improves the stability and flexibility of the system.

This invention relates to the field of power electronic converter control technology, specifically to a fault ride-through control method for a hybrid grid system, comprising: S1: calculating the corresponding reference frequency and reference voltage amplitude based on point of common coupling data; S2: calculating the corresponding active power reference value and reactive power reference value for each GFL converter using reverse droop control; S3: calculating the additional reactive power required for each GFL converter and updating the reactive power reference value for each GFL converter; S4: calculating the corresponding reference frequency and reference voltage for each GFM converter using direct droop control; S5: designing a current loop to generate a modulation control signal to drive the operation of the corresponding GFL converter; S6: designing voltage and current loops to generate modulation control signals to drive the operation of the corresponding GFM converter. This invention can meet the needs of power systems with a high proportion of renewable energy sources in scenarios such as fault ride-through optimization, stable operation control, relay protection configuration, and power grid planning and design.

This invention belongs to the field of power electronic converter technology, specifically disclosing a direct optimization model predictive control method and system for an MMC-STATCOM system. The method includes: calculating the differential-mode voltage and common-mode voltage between the upper and lower arms of each phase; injecting third harmonic voltage into the upper and lower arms of each phase to obtain the upper and lower arm voltages of the newly added third voltage component for each phase; based on the obtained upper and lower arm voltages of the newly added third voltage component, determining the number of sub-modules to be engaged in each phase's upper and lower arms using a nearest-level approximation modulation strategy; sorting the sub-modules according to the capacitor voltage of each sub-module in the arm; and determining the engaged sub-modules for each arm according to the current direction. This invention, while maintaining the discrete control structure, achieves direct injection of third harmonic voltage under the MPC framework, exhibiting higher real-time performance and scalability.

This invention discloses a broadband oscillation suppression method for grid-connected energy storage systems, belonging to the field of power electronic converter control technology. This method acquires grid-connected voltage and current signals in real time, analyzes the oscillation energy of each sub-band using a sliding window FFT, and when broadband oscillation is detected, uses the center frequency of the sub-band with the largest oscillation energy as the target frequency. It identifies the grid impedance and converter impedance online and calculates the impedance ratio. Then, based on the impedance ratio magnitude, it adaptively adjusts the virtual impedance parameters to reshape the converter impedance characteristics and suppress oscillation. This invention uses the "sub-band with the largest oscillation energy" as the trigger condition to avoid full-band scanning and uses the "impedance ratio magnitude" as the adaptive update variable. It can suppress broadband oscillations of 2.5Hz to 1000Hz within 30ms, is suitable for extremely weak power grids with SCR < 1.5, and consumes less than 3% of DSP computing power.

This utility model relates to a multi-source system comprising a motor (M) of the type including a rotor and a stator (1), the stator (1) comprising a plurality of windings (10, 11, 12) made of turns of isolated conductive material, each winding (10, 11, 12) comprising a plurality of independently powered coils (100, 101, 102), wherein the system further comprises a plurality of DC power supplies and a plurality of power electronic converters associated with the different coils (100, 101, 102) of the motor (M), each power supply supplying power to one or more power electronic converters, and each power supply being connected to at least one coil (100, 101, 102) of each winding (10, 11, 12) of the motor (M).

This invention discloses a hybrid modulation method for a four-switch Buck-Boost converter, relating to the field of power electronic converter control technology. Specifically, it includes: acquiring the converter's load state parameters and comparing them with a switching threshold determined based on a loss balance point. When the load is greater than or equal to the threshold, a four-segment modulation mode is used; when the load is less than the threshold, a five-segment modulation mode is used. In the five-segment modulation mode, when the inductor current drops to zero, the third switch is turned off and the fourth switch is turned on to enter a zero-current holding stage. After this stage, the second and third switches are turned on to establish a reverse current. This aims to eliminate free circulating current when the load is less than the threshold, reducing conduction losses and copper losses while ensuring zero-voltage turn-on, thereby improving converter operating efficiency.

The invention relates to a power electronic converter, such as an inverter or converter, for electrical applications, such as motor drives, electrolyzers or chargers. The power electronic converter includes a DC link and an active front end (AFE) connected to a grid via a filter and a grid plate. The grid plate has a first surge relay. The first surge relay has a resistive device. The resistive device may be a resistor, more specifically an NTC resistor or a PTC thermistor. The power grid plate further comprises a second surge relay. During a start-up phase of the power electronic converter and during abnormal grid voltage conditions, the at least one surge relay is controlled to turn on or off such that the DC link is charged via or bypassing the resistive device, and the AFE is used to boost the voltage of the DC link to a safety level and in a controlled condition. The invention also relates to an electric motor drive and to a method for operating a power electronic converter.

This invention belongs to the field of power electronic converter technology and discloses an automatic current-sharing high-gain boost converter and its application in photovoltaic charging devices. This automatic current-sharing high-gain boost converter employs two different voltage multiplier units, inserted at the midpoint of the bridge arm of a two-phase interleaved parallel circuit, and then cascaded with a half-wave rectifier circuit. This ensures that each inductor discharge circuit contains (m+n+1) diodes, thereby automatically achieving inductor current sharing. Furthermore, it achieves a voltage gain of 2(m+n+1) / (1-D) with a relatively small number of components, and features low switching transistor voltage stress, low diode voltage stress, low input current ripple, and common ground drive for all switching transistors. The boost requirements can be flexibly met by freely matching the number of switched capacitors n and m in the boost unit.

This invention belongs to the field of power electronic converter technology, specifically disclosing a parallel system of a full-bridge T-type LLC converter and a wide-gain-range interleaved current sharing method. The system includes: two-phase parallel-connected LLC converters, each phase LLC converter including an input capacitor, a T-type full-bridge primary side structure, a resonant cavity, a transformer, and a secondary side structure connected in sequence; the T-type full-bridge primary side structure includes: an upper half-bridge composed of four switching transistors Q1-Q4 and a lower half-bridge composed of switching transistors Q5-Q8; by introducing a T-type full-bridge structure, this invention can effectively improve the output gain range and achieve interleaved current sharing control under a wide output gain range.

The application discloses a kind of based on converter ripple communication's collaborative noise masking secure communication method and system, applied to including at least two power electronic converters and the power transmission line connected to its power electronic system;Source converter superimposes information signal in power control loop, and forms information carrier in power transmission line by pulse width modulation;Sink converter synchronously superimposes collaborative noise signal in power control loop, and injects collaborative noise carrier with the same frequency as information carrier in power transmission line, so that information carrier and collaborative noise carrier are superimposed to form hybrid carrier on power transmission line;Sink converter constructs noise transfer characteristic estimation model using collaborative noise signal injected by itself, and carries out collaborative noise carrier component elimination processing to recover information carrier;The application does not need to add new communication line or special encryption hardware, and can realize the improvement of power electronic system communication security.

This invention proposes a collaborative control method and system based on a hybrid power electronic transformer, belonging to the field of active distribution network operation and control technology. The method includes the following steps: configuring the topology of the hybrid power electronic transformer; continuous-layer global optimization to construct an equivalent model of the hybrid power electronic transformer, ignoring the physical discrete constraints of the equipment, defining continuous decision variables and decision vectors, and introducing a comprehensive objective function with a hierarchical penalty mechanism; executing an improved whale optimization algorithm to optimize the comprehensive objective function, outputting a globally optimal continuous vector as the theoretically optimal electrical operating state of the hybrid power electronic transformer; establishing a linear superposition relationship between the ideal total turns ratio target value output by continuous optimization and the compensation turns ratio provided by the mechanical tap and the power electronic converter based on the hybrid power electronic transformer topology; constructing and calculating the feasible region of the electronic capacity constraint of the power electronic converter; and combining the feasible region to execute a minimum action decision based on inertia maintenance.