306 results about "Zero voltage" patented technology

The invention discloses a TCM-mode-based Si-SiC hybrid power multi-phase staggered H-bridge converter structure and a control method thereof, according to the scheme, a three-phase staggered parallel topology of a two-phase low-frequency Si-IGBT bridge arm and a one-phase high-frequency SiC-MOSFET bridge arm is adopted, and a TCM control strategy is combined, so that zero voltage switching (ZVS) of a Si device is successfully realized, the switching loss is remarkably reduced, and the switching efficiency is improved. The system efficiency is greatly improved; and meanwhile, through pilot frequency interleaving and ripple compensation technologies, total output current ripples are greatly reduced, and optimal balance between system performance and manufacturing cost is realized while the power capacity of the converter is remarkably expanded and the dynamic response speed and the output electric energy quality are improved.

The invention provides a zero-voltage ride-through control method for a self-synchronizing voltage source doubly-fed wind turbine generator, which comprises the following steps that: when the self-synchronizing voltage source doubly-fed wind turbine generator is in a transient state, a grid-side converter adopts vector control, and a rotor-side converter adopts additional virtual impedance and annular current limiting; the transient overcurrent of the grid-side converter and the rotor-side converter can be effectively suppressed, so that the continuous operation capability of the wind turbine generator in the zero-voltage ride-through period can be maintained; meanwhile, by improving the transient capacity and the transient reactive current amplitude of the converter, the transient voltage supporting capacity of the wind turbine generator during the zero voltage ride-through period can be effectively provided; when the self-synchronizing voltage source doubly-fed wind turbine generator set is in a transient state, overvoltage of direct-current bus voltage is limited by a Chopper circuit, active-priority current amplitude limiting control is adopted by a grid-side converter, parameters of a current inner ring PI controller of a rotor-side converter are optimized, energy balance of a direct-current side can be achieved in the zero-voltage ride-through period, and stability of the direct-current bus voltage is maintained.

Disclosed is a system for zero voltage switching in a power converter with a first half-bridge and a second half-bridge. The first half-bridge has a first set of transistors and output inductor. The second half-bridge has a second set of transistors and auxiliary inductor. A current sensing means measures, at switching cycle scale, average and maximum current values of output inductor and average, minimum and maximum current values of auxiliary inductor. A voltage sensing means measures input and output voltages of first and second half-bridge. A controller is configured to compute dead times of pulse width modulation control signal of second half-bridge, generate pulse width modulation control signal of second half-bridge and to adapt dead times of first half-bridge.

The invention discloses a detection device and a detection system for harmonic oscillator capacitors of a hemispherical resonator gyroscope, and relates to the technical field of capacitor detection, the detection device comprises a signal detection circuit, a modulation compensation circuit, a differential amplification circuit and a control circuit, the signal detection circuit is connected with the output ends of the two harmonic oscillator capacitors; the modulation compensation circuit is correspondingly connected with two input ends of the signal detection circuit; the differential amplification circuit is correspondingly connected with two output ends of the signal detection circuit; the control circuit is configured to output modulation voltage to the two input ends of the modulation compensation circuit according to a voltage signal of the output end of the differential amplification circuit, and zero setting is carried out on voltage at the connecting positions of the two output ends of the modulation compensation circuit and the two input ends of the signal detection circuit. According to the invention, the modulation compensation circuit is adopted to enable the output ends of the two harmonic oscillator capacitors to work near zero voltage, the circuit has the characteristics of ultrahigh linearity, extremely low temperature drift, rapidness and stability, errors caused by power supply drift can be eliminated, and the detection precision is improved.

The invention discloses a half-bridge ZVS Buck-Boost converter and a control method thereof, and belongs to the technical field of power converters, the half-bridge ZVS Buck-Boost converter comprises a primary side conversion module, a voltage transformation module and a secondary side conversion module, and the primary side conversion module, the voltage transformation module and the secondary side conversion module are connected in sequence; the primary side conversion module comprises a first bridge arm, a second bridge arm, a first inductor and a bidirectional switch, the first bridge arm and the second bridge arm are connected in parallel, a bridge arm midpoint of the first bridge arm is connected with a first end of the first inductor, a second end of the first inductor is connected with a first end of the voltage transformation module, and a second end of the voltage transformation module is connected with a second end of the voltage transformation module. The second end of the voltage transformation module is connected with the bridge arm midpoint of the second bridge arm, the bridge arm midpoint of the first bridge arm is connected with the first end of the bidirectional switch, and the second end of the bidirectional switch is connected with the bridge arm midpoint of the second bridge arm. According to the invention, zero-voltage switching-on of the half-bridge circuit switching tube in a full-input, full-output and full-load range under a constant switching frequency can be realized.

The invention relates to the field of electronic power, particularly discloses a bridge resonant converter based on forward and reverse shock coordination of double transformers, and belongs to the technical field of power electronic conversion. Aiming at the problems of over-high peak current, high magnetic core saturation risk, remarkable switching loss and the like of a traditional LLC resonant converter under the requirements of a wide load range and high power density, the invention provides the following innovative schemes: a dual-transformer forward and reverse excitation collaborative structure, a zero voltage switching (ZVS) driving technology and resonant network parameter optimization.

The invention relates to the technical field of electric energy conversion, and discloses a high-frequency resonant topology-driven isolation power conversion system, which comprises a power conversion circuit, a driving unit, a feature sensing unit and a logic regulation and control unit, and is characterized in that the logic regulation and control unit extracts a parasitic ringing extreme point of a voltage evolution waveform in dead time; a charge release balance point is determined by calculating an arithmetic mean value of the first wave crest and the first wave trough, and high-frequency parasitic parameter interference is stripped; and predicting a time domain window of a return-to-zero potential based on a charge release balance point, performing phase compensation on a driving pulse in the time domain window according to a voltage waveform second derivative feature, and locking the starting moment of a switching tube at a zero voltage point. Interference of high-frequency distribution electromagnetic parameters on conduction judgment is eliminated, and soft switching self-healing in a full-load domain is achieved.

The invention discloses a control method, and particularly relates to an energy storage power converter self-adaptive control method based on digital twinning, which comprises the following steps: step 1, digital twinning model synchronization and state sensing; step 2, multi-target collaborative optimization based on prediction; and step 3, optimizing instruction issuing and physical system execution. Through real-time prediction and optimization of the digital twinborn model, it is ensured that the power switch tube always works in a zero-voltage switching state, switching loss is effectively reduced, and overall efficiency is improved. Dynamic thermal balance management is realized by combining thermal model prediction, local overheating is avoided, the service life of devices is prolonged, and the reliability of long-term operation of the system is enhanced.

The invention discloses a trapezoidal wave current soft switching method of an interleaving DC-DC converter, which is used for a two-phase interleaving bidirectional DC-DC converter based on a coupling inductor and a multi-phase interleaving converter thereof, and is characterized in that an inductive current adopts a trapezoidal wave mode, so that the converter works in an approximate critical conduction mode; a fixed switching frequency control or hybrid control method is adopted, so that the device can work in a Buck mode and can also work in a Boost mode. The method for realizing the soft switching is characterized in that the parasitic capacitance or the external resonant capacitor of the switching tube is discharged to be zero under the resonance action of the inductor and the capacitor in the dead zone time when the upper bridge arm switch and the lower bridge arm switch are alternately switched on, so that the zero-voltage switching-on of all the switching tubes is realized. And each phase current sharing control is adopted in the multi-phase interleaving parallel topological structure. According to the invention, the problems of large current peak value and high turn-off loss of a traditional triangular wave current mode are solved, the output ripple current is reduced, a soft switching method is provided, the switching loss is reduced, and the conversion efficiency of the converter is improved.

Techniques for valley detection in flyback power converters. In an example, circuitry implementing the techniques is configured to detect a positive slew at the onset of the leakage reset portion of the switching terminal signal, and to blank out the leakage reset portion. The circuitry is also configured to detect a negative slew of the leakage ringing portion of the switching terminal signal, and to blank out any false valley detections that occur during the leakage ringing portion. The blanking periods may be fixed or variable. The circuitry may also be configured to discern the difference between a true valley that reaches zero voltage within the magnetizing ringing portion and a false valley within the leakage ringing portion.

The application provides a driving method of an inverter bridge, a driving circuit, a servo driver and a motor device. In the driving method of the inverter bridge, voltage vector output time and dead time are set, so that a power switch tube of a jth bridge arm is kept in a conduction state in two adjacent voltage vector output times before switching, the power switch tubes kept in the conduction state are changed in turn and staggeredly, in each dead time, two other power switch tubes kept in the conduction state in a previous voltage vector output time are switched off, the corresponding switching bridge arm and winding complete resonance work, the end voltage of the power switch tube to be turned on is clamped to zero potential, zero voltage conduction is realized, a soft switching mode is formed, and the switching loss is reduced and the power conversion efficiency is improved.

The invention discloses a high-power-density modular B2G converter soft switching control method, system and device and a medium, and belongs to the technical field of converter control, and the method comprises the steps: constructing a two-stage converter topological structure; a frequency conversion and phase shift mixed soft start strategy is introduced, and soft start is carried out on the two-stage converter topological structure; according to the current transmission direction of the two-stage converter topological structure, selecting a control strategy according to the current transmission direction; soft switching control operation is carried out on a front-stage unit and a rear-stage unit in the two-stage converter topological structure, so that zero-voltage switching-on of an auxiliary switching tube is realized and the zero-voltage switching-on is maintained; an auxiliary resonance circuit is introduced, zero-voltage switching-on of a high-frequency bridge arm switching tube and an auxiliary switching tube is achieved through two times of resonance, and a rear-stage unit is designed to be an isolated bidirectional symmetrical CLLLC resonance type converter topology to be matched with closed-loop frequency adjustment; during soft start, a frequency conversion and phase shift mixed strategy is adopted, system energy is smoothly established through phase shift control, and starting current impact is restrained.

The application provides a circuit control method and a circuit control device thereof, which are applied to a hybrid flyback circuit. The method comprises the following steps: determining a collection time point according to the alternating time length of the conduction of a first MOS switch and a second MOS switch on the main side of the hybrid flyback circuit and a preset time coefficient; collecting a midpoint voltage between the first MOS switch and the second MOS switch according to the collection time point to obtain a first voltage signal; and adjusting a field excitation negative current in the hybrid flyback circuit according to a comparison result of the first voltage signal and a preset voltage value, so that the field excitation negative current meets the zero-voltage turn-on of a primary measurement switch of the hybrid flyback circuit.

Provided is a current resonance type switching power supply device with a simple configuration that has a wide variable range of output voltage and can also achieve ZVS of the main switching element. 【Solution means】The switching power supply device 38 includes a ZVS auxiliary circuit 40 formed by a series circuit of an auxiliary diode 42, an auxiliary inductor 44, and an auxiliary DC power supply 46, which is connected in parallel across both ends of the main switching element 14(2). The switching control circuit 36 determines first and second on-times ton1 and ton2 based on the control voltage Vs of the output by the error amplification circuit 34, and provides a dead time Td to turn on and off the main switching elements 14(1) and 14(2) complementarily. When the first on-time ton1 is ton1 ≧ Tk, control of the first operation mode is performed to set the second on-time ton2 to ton2 = ton1. When the first on-time ton1 becomes ton1 < Tk, control of the second operation mode is performed to set the second on-time ton2 to ton2 > ton1.

The invention discloses a bidirectional DC-AC converter control method considering a soft switching condition and current optimization. According to the invention, the switching loss of the converter is reduced by optimizing the phase shift angle and the switching condition of the converter, and the energy transmission efficiency is optimized by minimizing the effective value of the current, so that the performance of the whole sodium battery energy storage system is improved. Specifically, based on the relation between the excitation inductance Lm and the current effective value Iprms, the phase shift angle of the converter is accurately controlled, the current transmission efficiency is optimized, and it is ensured that the zero-voltage switching condition of a primary side bridge arm and a secondary side bridge arm can be achieved in the working process, so that the loss of the converter is remarkably reduced, and the energy conversion efficiency is improved.

A circuit is disclosed. The circuit includes a transformer having a primary winding extending between a first terminal and a second terminal, and further including a secondary winding extending between a third terminal and a first output terminal; a first switch having a first gate terminal, a first source terminal and a first drain terminal, the first drain terminal coupled to the second terminal and the first source terminal coupled to a power source; a second switch having a second gate terminal, a second source terminal and a second drain terminal, the second source terminal coupled to the second terminal, and the second drain terminal coupled to the power source; and a third switch having a third gate terminal, a third source terminal and a third drain terminal, the third source terminal coupled to the third terminal and the third drain terminal coupled to a second output terminal.

The invention provides a multi-resonant switched capacitor efficient cooperative operation method suitable for battery active equalization, and the method comprises the steps: building a zero-voltage soft switching realization condition model of a single-module resonant unit, and determining the amplitude constraint and direction constraint of a soft switching current needed by a switching tube for realizing zero-voltage switching; based on topology, identifying current paths of the half bridges located at the top layer, the middle layer and the bottom layer in the soft switching transient process, and determining a mathematical relationship between the soft switching current of each layer of half bridge and the current of each resonant cavity; respectively establishing equivalent circuit models at switching moments for the top-layer half-bridge, the middle-layer half-bridge and the bottom-layer half-bridge, and solving to obtain each initial current value of the corresponding junction capacitor voltage at the switching moments; and substituting each initial current value obtained by solving into the established constraint condition, and drawing an operation parameter boundary of the topology capable of realizing soft switching in all working modes. According to the invention, by determining the operation boundaries of all half-bridge soft switches of the multi-resonant switched capacitor structure, the switching loss is reduced, and the operation efficiency is improved.

Methods for switching the power source supplying an alternating current (AC) electrical load from a first AC power supply to a second AC power supply comprising: (a) determining, during a time period, the zero voltage crossings of at the first and second AC power supplies; (b) estimating for a future time period, based on information obtained in said determining step (a), the times at which a series of future current zero-crossings of said AC load and at least the current zero-crossing of the second power supply; (c) based on said estimating step (b), determining whether during said future time period the time of said zero-crossing of said load current and the zero-crossing of the second power supply are within about 0.1 microseconds of each other; and (d) for a time period during which said zero crossings are estimated to be within 0.1 microseconds of each other, switching said load to said second power supply at said time at which said zero crossings are estimated to be within 0.1 microseconds of each other, wherein said switching: (i) uses a solid-state switching system and microprocessor-based control system for actuating said solid-state switching circuit; and (ii) accounts for any known actuation delay between the actuation signal from said microprocessor and the occurrence of said switching.

The utility model relates to the technical field of converters, in particular to a DAB converter adopting a bidirectional switch tap inductor, which comprises a primary side structure and a secondary side structure. The primary side structure comprises a direct current power supply Uin, an input capacitor Cin, a first power switch tube S1, a second power switch tube S2, a third power switch tube S3, a fourth power switch tube S4, a high-frequency inductor L, an excitation inductor Lm, a bidirectional switch tap inductor Lt and a transformer T; and the secondary side structure comprises a load resistor RL, an output capacitor Cout, a fifth power switch tube S5, a sixth power switch tube S6, a seventh power switch tube S7 and an eighth power switch tube S8. According to the converter, equivalent magnetization inductance is changed through bidirectional switch tap inductance, equivalent magnetization current is increased, zero-voltage switching-on is realized, switching loss is reduced, and the conversion efficiency is improved. When the input voltage and the output load are suddenly changed, good dynamic response capability is maintained, and zero-voltage switching operation is realized in a wide load and wide battery voltage change range.

The utility model discloses a composite switch control circuit of a charging pile relay, which relates to the technical field of electronic circuits, and is characterized in that a first relay K1 is connected in series with a second relay K2, the second relay K2 is connected in parallel with a thyristor Q1, the thyristor Q1 is connected in parallel with an output optocoupler U1, and the thyristor Q1 can be driven by the output optocoupler U1. The method comprises the following steps: ensuring that closing and opening of a thyristor Q1 are executed at a zero voltage position, enabling an output optocoupler U1 to have a zero cross trigger function, in a charging process, firstly closing a first relay K1, secondly controlling whether the thyristor Q1 starts to be switched on or not through the output optocoupler U1 to supply power to a rear stage, and finally controlling closing of a second relay K2, when charging is completed, firstly opening the second relay K2, and then opening the second relay K2 through the output optocoupler U1 to supply power to the rear stage. And secondly, the thyristor Q1 is switched off, and then the first relay K1 is controlled to be switched off, so that arcing and adhesion phenomena caused by switching-on and switching-off of the relays under the on-load condition are finally avoided, and the probability of damage to contacts of the relays is reduced.

The application discloses an improved double-vector model prediction permanent magnet synchronous motor flux linkage control method. Firstly, the first optimal voltage vector, two adjacent effective voltage vectors and a zero voltage vector are taken as the candidate voltage vectors of the second optimal voltage vector, the global optimal voltage vector combination is obtained through the second optimal voltage vector selection table and the selection rule, instead of only selecting the first optimal voltage vector and the second optimal voltage vector as the local optimal voltage vector combination of the zero voltage vector, so as to reduce the stator flux linkage ripple; then, a new duty cycle calculation method is proposed by defining the stator flux linkage deviation factor, and the calculation burden of the system is reduced. Compared with the traditional duty cycle model prediction flux linkage control algorithm, the application improves the local optimality of the optimal voltage vector combination obtained in the control method, the larger stator flux linkage ripple and other defects.

The invention discloses a direct current conversion device, a control method thereof and an optical storage system, and relates to the technical field of switching power supplies. Comprising a push-pull resonance circuit, a photovoltaic input circuit and an energy storage input circuit. The push-pull resonant circuit is adopted as a unified energy conversion core, and photovoltaic input and energy storage input share key components such as a transformer, a resonant network and a switching tube, so that a single-stage structure replaces independent multi-stage converters in a traditional scheme, the system architecture is simplified, and the size, the weight and the cost are reduced. Through the resonant soft switching technology, the switching tube works under the condition of zero voltage or zero current, the switching loss is reduced, and high-efficiency energy transmission is realized. Meanwhile, a third switching circuit of a photovoltaic end is specially used for tracking the maximum power point, and an energy storage end independently controls charging and discharging through a bidirectional circuit, so that the photovoltaic energy collection efficiency is guaranteed, and flexible scheduling and smooth fluctuation of power are realized.

The invention discloses a full-direct-current offshore wind power system zero-voltage ride-through method, equipment and a medium, and relates to the field of full-direct-current offshore wind power. The objective of the invention is to solve the problem that a receiving-end converter station cannot transmit power when a land AC power grid breaks down. When the high-voltage direct-current voltage of the offshore direct-current transformer exceeds the first preset threshold value, the medium-voltage direct-current voltage control of the offshore direct-current transformer is switched to the high-voltage direct-current voltage control, so that the offshore direct-current transformer absorbs power from a high-voltage direct-current link; when the medium-voltage direct-current voltage of the fan direct-current transformer exceeds a second preset threshold value, the fan direct-current transformer is switched from low-voltage direct-current voltage control to medium-voltage direct-current voltage control, so that the fan direct-current transformer can absorb power from the low-voltage direct-current voltage side through a fan grid-side direct-current transformer; and when the low-voltage direct-current voltage of the offshore direct-current transformer exceeds a third preset threshold value, the brake resistor is activated to dissipate surplus power until the low-voltage direct-current voltage is lower than a fourth preset threshold value.

The invention discloses a solid-state power controller resonance mode zero-voltage switching-on method based on variable inductance, belongs to the technical field of power electronic conversion, and aims to solve the problems that when a solid-state power controller is started, the peak stress of a device is large, the heat dissipation requirement is large, and the load adaptability is poor. The circuit comprises a resonant network, a main loop power tube and an auxiliary power tube, wherein the resonant network consists of a variable resonant inductor and a pre-charging capacitor; a variable resonant inductor is used for performing parameter matching on different resistive, inductive and capacitive loads to control a resonant mode to be in a critical damping state, so that a pre-charging capacitor discharges in a fastest non-oscillation manner to realize zero-voltage switching on of a main power tube and zero-current switching on and off of an auxiliary power tube; a resonant cavity energy recovery device is arranged to transmit resonant energy to a load. The circuit significantly reduces peak stress when a main loop device is started, reduces switching loss of an auxiliary loop device, recovers resonance energy to a load end, reduces heat dissipation requirements, adapts to load scenes with different properties, and is suitable for the field of high power and high reliability.

This invention discloses a method, system, medium, and product for optimizing the peak current of a dual active bridge extended phase-shift converter, belonging to the field of power electronics control. The method involves: obtaining the voltage conversion ratio and internal / external phase-shift duty cycles of the dual active bridge converter; constructing an inductor current peak function under extended phase-shift modulation, a penalized power balance equation, and a zero-voltage turn-on inequality constraint; initializing a particle swarm with the internal / external phase-shift duty cycles as particle positions; constructing a fitness function based on the minimum current peak value and constraints; iteratively solving for the optimal phase-shift parameters using a particle swarm optimization algorithm; and dynamically adjusting the constraint penalty weights based on the particle violation ratio during iteration; finally, generating a modulation signal based on the optimal phase-shift parameters to control the switching transistors, completing the optimization. By implementing this invention, the problem of poor convergence stability of existing optimization algorithms under wide operating conditions can be solved.

The biasing of one or more field plates of a high electron mobility transistor (a HEMT) with a non-zero voltage to thereby affect the electric field profile of the HEMT. The non-zero voltage may be a constant DC voltage, or perhaps may be a voltage that changes over time. The use of a non-zero voltage allows for greater ability to regulate and reduce the electric field occurring in the semiconductor channel region, especially at the field plate. Further, when the electric field occurring at the field plate is reduced, the overall size of the HEMT can also be reduced as compared to applying a zero voltage to the field plate. Alternatively, or in addition, applying a non-zero voltage to the field plate allows the voltage levels handled by the HEMT to be increased as compared to simply grounding the field plate.

Methods for switching the power source supplying an alternating current (AC) electrical load from a first AC power supply to a second AC power supply comprising: (a) determining, during a time period, the zero voltage crossings of at the first and second AC power supplies; (b) estimating for a future time period, based on information obtained in said determining step (a), the times at which a series of future current zero-crossings of said AC load and at least the current zero-crossing of the second power supply; (c) based on said estimating step (b), determining whether during said future time period the time of said zero-crossing of said load current and the zero-crossing of the second power supply are within about 0.1 microseconds of each other; and (d) for a time period during which said zero crossings are estimated to be within 0.1 microseconds of each other, switching said load to said second power supply at said time at which said zero crossings are estimated to be within 0.1 microseconds of each other, wherein said switching: (i) uses a solid-state switching system and microprocessor-based control system for actuating said solid-state switching circuit; and (ii) accounts for any known actuation delay between the actuation signal from said microprocessor and the occurrence of said switching.

The application belongs to the technical field of switching power supply, and an auxiliary circuit is added between two branches of a traditional two-phase Dickson converter; in a dead time when all main power tubes are closed, the auxiliary circuit can transfer the charge of one branch to another branch, realizes zero-voltage turn-on of all main power tubes, and reduces switching loss.

The invention discloses a multi-output switching power supply and a control method thereof. A first output loop in the multi-output switching power supply comprises a first synchronous rectifier tube and a first output switching tube; a first feedback signal is obtained according to the output feedback signal of the first output loop, and a second feedback signal is obtained according to the output feedback signal of at least one of the other output loops; a zero-voltage conduction pulse signal is generated according to the second feedback signal to conduct a first synchronous rectifier tube, so that a negative current is generated on a main power tube in the input loop; a first output control signal synchronous with a zero voltage conduction pulse signal is generated according to the first feedback signal and the zero voltage conduction pulse signal so as to control the on-off state of the first output switch tube; according to the invention, the synchronization between the first output switch tube and the main power tube can be realized without adopting a complex synchronization signal generation circuit, the control is simple, and the cost is low.

The invention discloses a wireless electric energy transmission system based on impedance self-adjustment and an efficiency improvement method thereof, and belongs to the technical field of wireless electric energy transmission. The system comprises a DC voltage source, an inversion module, a primary side compensation network, an integrated coupling mechanism, a secondary side compensation network, a rectification module, a filter capacitor and a load. The integrated coupling mechanism integrates the primary side compensation inductor, the secondary side compensation inductor and the coupling coil into a whole to form a self-adjusting variable inductor changing along with an air gap. Then, based on a second-generation non-dominated sorting genetic algorithm, multi-objective optimization is carried out on compensation capacitance and input voltage, and optimal parameters are determined under detuning degree constraint by taking minimization of output voltage fluctuation and total loss of the system as objectives; constant voltage output is achieved through phase shift control, and all-working-condition zero-voltage switching is achieved. The device does not need additional variable impedance elements, has the advantages of being simple in structure, stable in control, high in efficiency, high in air gap fluctuation resistance and the like, and is suitable for air gap dynamic change scenes such as wireless charging of automatic guided vehicles and electric vehicles.