632 results about "Soft switching" patented technology

The invention relates to the technical field of flexible direct-current power transmission, in particular to a centralized local energy storage modular multilevel converter MMC-CLES topology which comprises three phase units, each phase unit comprises an upper bridge arm and a lower bridge arm, and each upper bridge arm and each lower bridge arm comprise a bridge arm reactor arranged at one end, close to a power grid, of the bridge arm; a plurality of identical sub-modules SM which are connected to a power grid through a bridge arm reactor; the upper bridge arm and the lower bridge arm form a symmetrical structure; an energy storage sub-module is arranged at the position where the three-phase unit is directly connected with the direct-current bus. According to the invention, the control system is simplified, and the hardware cost and the control complexity are reduced. Voltage stress and current stress are smaller, higher power can be borne, and the high-power capacitor is suitable for being applied to high-power occasions. And moreover, due to the symmetrical layout, the control method is relatively simple, soft switching can be realized, and the power divider can be used as a multi-port component unit.

The invention discloses a single-stage bidirectional power conversion topological structure capable of realizing wide-range soft switching and a control method of the single-stage bidirectional power conversion topological structure. In-bridge and inter-bridge phase shift control of a double-half-bridge circuit and a high-frequency switch matrix provides a basis for realizing soft switching of all power tubes; the switching frequency is adjusted in real time according to the magnitude of the port voltage, soft switching within a wide voltage change range is achieved, the current of a bridge arm connected with the primary side of the second transformer is the sum of the primary side current of the second transformer and the current of an inductor connected in parallel with the second transformer, and the inductance value of the inductor connected in parallel with the primary side of the second transformer is designed. The current of the bridge arm connected with the primary side of the second transformer can be effectively changed, so that the soft switching implementation range of the switching tube of the bridge arm connected with the primary side of the second transformer in a wide power transmission range can be expanded.

The invention discloses a multi-objective optimization method and system for dual active bridge circuit expansion phase shift modulation, and the method comprises the steps: calculating a voltage matching ratio, and determining an external phase shift angle ratio based on a difference value between an output voltage and an output voltage reference value; according to the voltage matching ratio and the external phase shift angle ratio, obtaining an internal phase shift angle ratio of the primary side full bridge through an offline lookup table; calculating the maximum transmission power of the dual-active bridge converter, and determining a current working mode from the six preset working modes based on the size relationship between the inner phase shift angle ratio and the outer phase shift angle ratio; generating an optimal modulation strategy through a multi-objective optimization algorithm by taking the current effective value and the current peak value as optimization objectives and combining the voltage matching ratio and the periodic parameters of the current working mode; and generating a trigger signal of each switch tube of the dual-active bridge converter. Through six-mode working area division, complete differential algorithm boundary constraint and off-line-on-line collaborative optimization, the contradiction between the current stress and the soft switching range of the converter under extended phase shift modulation is solved.

The invention discloses a flexible interconnected power distribution network active-reactive optimization method considering electric energy quality requirements, and belongs to the technical field of power distribution network optimization operation. The invention aims to provide the active-reactive optimization method for the flexible interconnected power distribution network considering the electric energy quality demand, which simultaneously optimizes the voltage deviation, feeder balance and network loss of the power distribution network through various control means such as soft switching power regulation participation response. The method comprises the following steps: proposing a flexible interconnection system power quality demand subjective and objective weighting evaluation method through calculation of a flexible interconnection system day-ahead index time sequence value, and proposing a flexible interconnection power distribution network active-reactive power optimization model considering a node comprehensive weight through coordinated operation of a traditional network side resource and an intelligent soft switch. According to the invention, the active-reactive optimization method of the flexible interconnection power distribution network considering the power quality demand is analyzed, the effective cooperation of the flexible interconnection device and the controllable network side resource regulation and control is explored, and the influence on the voltage deviation, feeder balance and network loss of the power distribution network is optimized by multiple control means at the same time; and reference is expected to be provided for guiding optimal scheduling of the flexible interconnected power distribution network.

The invention provides a modulation and control method of a bridge arm multiplexing type FSBB-CLLLC bidirectional converter, belongs to the technical field of power electronics, and solves the problems that the modulation method of the bridge arm multiplexing type FSBB-CLLLC converter is not clear, the working principle is not clear, and the efficiency is reduced due to the fact that soft switching implementation is complex. The main circuit topology is divided into different bridge arms; different working modes of the converter during forward and reverse operation are researched by combining a bridge arm phase shift angle and a duty ratio; researching and solving the relationship between the inductive current and the phase shift angle of the converter by combining a modulation method and a soft switching condition, and establishing a three-dimensional table; according to different input and output voltage requirements, the duty ratio is determined, the optimal phase shift angle is determined after table look-up, and full-switching tube soft switching of the FSBB-CLLLC converter under voltage stabilization control is achieved.

The invention discloses a control method, a control device and a switching power supply, the control method is applied to a three-phase converter, and the control method comprises the following steps in a time interval: a sampling signal acquisition step: acquiring a first sampling signal representing the state of each phase, the state can represent the size relation of the maximum average switching current absolute value of each phase of bridge arm; in the working mode selection step, the working mode of the corresponding phase bridge arm is selected according to the first sampling signal of each phase, and when the maximum average switching current absolute value represented by the first sampling signal is maximum, the corresponding phase bridge arm works in a clamping mode; when the maximum average switching current absolute value represented by the first sampling signal is centered, the corresponding phase bridge arm works in a CRM mode; and when the maximum average switching current absolute value represented by the first sampling signal is minimum, the corresponding phase bridge arm works in a TCM mode. According to the invention, soft switching conditions can be provided for the three bridge arms of the three-phase converter.

The invention discloses a soft switching modulation method and system for minimum current stress in a full power range. The system comprises an expansion phase shift optimization unit, an in-loop direct power control unit and a cooperative control unit. The in-loop direct power control unit is used for obtaining dynamic correction power, the expansion phase shift optimization unit is used for generating a phase shift ratio combination [D1, D2] which simultaneously meets the minimum current stress and the ZVS condition, and the cooperative control unit generates a PWM driving signal according to the generated phase shift ratio combination [D1, D2] to achieve soft switching control. According to the invention, the problem of current stress minimization in a wide voltage range can be effectively solved, the problem of ZVS loss in a light-load working condition can be prevented, and a load / voltage sudden change condition can be coped with in time; through the design of the ZVS boundary guarantee, the method is especially suitable for scenes needing wide voltage range efficient energy transmission, such as new energy grid connection and electric vehicle charging.

The utility model provides a single-stage wide-input soft switching resonant power supply conversion device. The single-stage wide-input soft switching resonant power supply conversion device is characterized by comprising a Buck-Boost circuit and an LLC circuit, the Buck-Boost circuit comprises a switching tube Q1 and a switching tube Q2, and one switching tube Q2 is multiplexed as a lower tube of the LLC circuit. The single-stage wide-input soft switching resonant power supply conversion device is small in stress, has obvious advantages in thermal design and efficiency, and is more convenient for product development in practical application.

The invention discloses a soft switching HERIC non-isolated inverter and a modulation method thereof, and belongs to the technical field of inverters, the inverter comprises a bridge arm circuit, a clamping circuit, a resonance circuit, a voltage stabilizing circuit and a filter circuit, the resonant circuit comprises a first auxiliary switch tube, a second auxiliary switch tube, a third auxiliary switch tube, a fourth auxiliary switch tube, a first resonant inductor, a second resonant inductor, a first resonant capacitor and a second resonant capacitor; all high-frequency switches realize zero-current turn-on and turn-off at the same-direction stage of the voltage and the current of the power grid through the resonance circuit; all the high-frequency switches also realize zero-current switching on and switching off in the voltage and current reverse phase of the power grid; according to the modulation method, unipolar PWM modulation is adopted, the grid-connected current harmonic distortion rate is reduced, the grid-connected electric energy quality is improved, and the application value and prospect are huge.

The invention relates to an external phase shift angle determination method and system, a frequency conversion phase shift control method and a chip, and the method comprises the steps: obtaining an external phase shift angle based on a general solution of a time domain differential equation of a resonant inductor current and a resonant capacitor voltage of a DBSRC equivalent circuit and the symmetry of the DBSRC equivalent circuit; determining a first current value of the resonant inductor at the first moment and a second current value of the resonant inductor at the second moment; based on the first current value when the primary bridge circuit meets the ZVS soft switching requirement, obtaining a first relational expression of the external phase shift angle about the input voltage and the output voltage of the DBSRC and the switching frequency of the switching tube; based on a second current value when the secondary-side bridge circuit meets the ZVS soft switching requirement, obtaining a second relational expression of the external phase shift angle with respect to the input voltage, the output voltage and the switching frequency; according to the first relational expression, the second relational expression and the steady-state voltage value of the output end of the DBSRC, the expression of the external phase shift angle about the switching frequency, the steady-state voltage value and the input voltage is determined; the scheme is simple, the accuracy is high, and the portability is high.

The invention discloses an IGBT full-bridge series inverter power supply control system, which relates to the technical field of inverter power supplies and comprises an inverter output module, the inverter output module inverts direct-current electric energy accessed by a power supply module, and when the detected electric energy is larger than a first voltage threshold value or smaller than a second voltage threshold value, the inverter output module outputs the inverted electric energy. The intelligent control module controls the soft switching module to carry out zero-voltage and zero-current soft switching-on processing on a switching element which is not switched on in the inversion output module, the terminal voltage change rate of the switching element in a switched-off state is reduced, zero-voltage soft switching-off is carried out, and when the detected electric energy is smaller than a first voltage threshold value or a second voltage threshold value, the soft switching-off is carried out. The soft switch module cooperates with the auxiliary capacitor module to carry out half-bridge inversion and carries out output compensation or enlarges the output voltage range through the electric energy output by the series compensation module and the inversion control module. According to the IGBT full-bridge series inverter power supply control system, the switching loss can be reduced, the electric energy conversion efficiency and the power supply precision are improved, and the power supply voltage range is enlarged.

The invention provides a simulation method and system with controllable split-phase voltage drop time difference, and relates to the technical field of electric power testing, and the method comprises the steps: adjusting voltage through a three-phase voltage regulator, employing a bidirectional silicon controlled rectifier and IGBT hybrid switch structure to achieve voltage drop, collecting and processing a three-phase voltage signal through a digital signal processor, and extracting zero crossing point information; and a control pulse signal with phase compensation is generated, the conduction time sequence of the switch element is controlled to realize soft switching, and the industrial computer receives and processes the signal and displays a voltage drop waveform. The split-phase voltage drop time difference can be accurately controlled, and the simulation precision and the system reliability are improved.

The invention discloses a wireless electric energy transmission system based on a semi-active rectifier, which comprises an input power supply Vin, a transmitting side inverter unit, a transmitting side compensation circuit, a transmitting coil Lp, a receiving coil Ls, a receiving side compensation circuit, a receiving side semi-active rectifier and a load RL, one active bridge arm of the full-bridge active rectifier is replaced by a passive bridge arm which is composed of two diodes and does not need to be controlled, soft switching of all switching tubes on the receiving side is guaranteed while rectifier control is simplified, and a secondary side resonance current zero crossing point sampling circuit is simplified by utilizing the passive rectification characteristic of the passive bridge arm. The designed output voltage control and secondary side resonance current zero crossing point detection circuit is simple, convenient to control and easy to implement, and has a good application prospect.

The invention provides a soft switching control method, device and system of a converter and a readable storage medium, and the method comprises the steps: calculating a first modulation parameter of the converter, and generating a plurality of first target driving signals based on the first modulation parameter, so as to control the connection or disconnection of a corresponding first target switching tube through each first target driving signal, the closed-loop control of the output voltage and the input current of the converter is realized; calculating a second modulation parameter of the converter after closed-loop control based on the first modulation parameter; wherein one of the first modulation parameter and the second modulation parameter is a modulation ratio, and the other one is a phase shift ratio; generating a plurality of second target driving signals based on the second modulation parameter; wherein the driving signal corresponding to the modulation ratio is used for controlling each switching tube of the matrix circuit to be switched on or switched off, and the driving signal corresponding to the phase shift ratio is used for controlling each switching tube of the full-bridge circuit to be switched on or switched off. By implementing the scheme of the invention, soft switching of all switching tubes within a full voltage range and a full load range can be realized.

The invention discloses a half-bridge driving circuit and method in a multi-level topology based on an FPGA (Field Programmable Gate Array), the half-bridge driving circuit comprises an MCU (Microprogrammed Control Unit), an FPGA logic circuit and a signal isolation circuit, the FPGA logic circuit gathers fault signals of other circuits in a complete machine, when other circuits fail, the circuit is notified to carry out shutdown operation, and when the other circuits fail, the FPGA logic circuit does not fail, the signal isolation circuit does not fail. In the process of switching on to switching off and the process of switching off to switching on, a transition state that switching-on voltage and switching-off voltage are invalid exists in a period of time, impact in the state switching process is solved, soft switching-off of an outer tube and an inner tube of a power main device in the multi-level topology from outside to inside is achieved in case of a fault, and soft switching-off of the outer tube and the inner tube of the power main device in the multi-level topology is achieved. The gate driver has the advantages that the gate driver is simple in structure, combinational logic and complex sequential logic functions can be realized at low cost, the signal isolation circuit is used for controlling conversion and isolation of PWM (pulse-width modulation) pulse to voltage required by gate control signals of a power device of a main circuit, peak voltage limitation and inner and outer tube switching time sequences are realized, various faults can be monitored, and fault protection can be safely implemented.

The invention discloses a multi-motor dynamic synchronous regulation and control method based on virtual line shaft state feedback, and the method comprises the steps: constructing a multi-motor virtual line shaft control model, setting an expected traction torque value through the output of a virtual main shaft, and setting each physical motor as a following motor; according to the collected state data of each motor, performing joint probability modeling on the state and disturbance of each motor by adopting a preset modeling method, and generating an estimated mean value and a covariance of each motor state; designing a nonsingular terminal sliding mode surface and calculating a control signal; setting a soft saturation buffer area range, constructing a soft switching function, carrying out buffer correction on the control signal, and outputting a corrected control signal; and synchronous control of multi-motor traction output is realized according to the correction control signal. According to the multi-motor dynamic synchronous regulation and control method, the synchronous stability, the anti-interference capability and the output smoothness in a complex dynamic environment can be improved.

The present invention discloses a method for siting and sizing a flexible soft switch of a distribution network based on mixed second-order cone programming, including: acquiring interconnected flexible distribution system data; establishing and optimizing, based on the interconnected flexible distribution system data and an interconnected flexible distribution system constraint, a flexible soft switch siting and sizing model with a minimal daily comprehensive operation cost as an objective; and acquiring an optimal flexible soft switch siting and sizing solution by using combination of an improved sparrow algorithm and second-order cone programming to solve. The present invention is both reliable and economic.

The present application provides an on-board charger and a control method thereof. Since the transformer side of the AC / AC conversion circuit is connected to the AC side of the AC / DC conversion circuit via a transformer, the on-board charger has a single-stage structure. Furthermore, since the instantaneous sampling value of the grid-side current is equal to its instantaneous reference value when stable, and the instantaneous reference value of the grid-side current is determined by the phase of the instantaneous sampling value of the grid-side voltage and the reference peak value of the grid-side current, the on-board charger has a PFC function. Furthermore, since the battery-side charging power can be indirectly controlled by controlling the grid-side current, the on-board charger has a battery-side voltage and current control function. Furthermore, since phase shift control is performed on the two conversion circuits, and the phase shift control enables soft switching of the power devices in the two conversion circuits, and the single-stage structure reduces the current flowing through the devices, efficiency is improved. Therefore, the single-stage structure efficiently implements the PFC and battery-side voltage and current control functions of the two-stage isolated on-board charger.

The invention discloses a control method and system for a single-stage three-port V2G charging device, and relates to the technical field of charging pile converters, and the method comprises the steps: constructing a structure of a three-port converter, and obtaining a working mode of the converter; a phase shift control mode is adopted between the ports and between the two bridge arms of the full-bridge circuit; bidirectional power flow of energy between a power grid and a new energy automobile battery is completed, and multifunctional charging and discharging management is achieved. The converter is of a single-stage structure and has high power density, and flexible and bidirectional power exchange between alternating current and direct current ports can be achieved without a two-stage structure. In order to improve the efficiency of the converter, a phase shift angle is calculated by taking power as a constraint condition and taking current stress and soft switching as optimization targets, a three-port converter optimization modulation strategy which is suitable for the topology and takes a wide soft switching range and low current stress into account is designed, and efficient and reliable operation of the converter in three working modes of V2G, G2V and H2L can be realized.

The invention belongs to the technical field of power electronics, and discloses a global efficiency optimization-based four-switch Buck-Boost + LLC integrated topology modulation method, which comprises the following steps of: determining an optimal working point under a specified working condition point through three constraint conditions of gain, soft switching and loss according to three degrees of freedom, namely two duty ratios d1 and d2 and a phase shift angle phi; and pulse width modulation and phase shift modulation are carried out on the integrated topology. Correspondingly, the invention provides a controller which is used for executing the specific steps of the modulation method of the four-switch Buck-Boost + LLC integrated topology based on global efficiency optimization in the invention. According to the modulation strategy provided by the invention, the loss of the four-switch Buck-Boost + LLC integrated topology in a wide input range can be reduced while soft switching in a full-load range is ensured, and an external circuit does not need to be additionally arranged, so that the integrated topology has high power density and high efficiency.

The invention discloses a power distribution network-micro-grid coordinated optimization scheduling method and device, a medium and equipment in the technical field of intelligent power grids, and aims to solve the problems of low response speed, limited adjustment capability and insufficient intelligence in the prior art. The method comprises the following steps: acquiring a pre-constructed optimal scheduling model based on dynamic networking and electricity price excitation; and solving the optimal scheduling model based on dynamic networking and electricity price excitation based on the safe operation parameters of the target power distribution network, the safe operation parameters of the micro-grid and an electricity price excitation strategy of the micro-grid, and generating an optimal scheduling scheme. Through organic combination of intelligent soft switching, dynamic networking and an electricity price incentive mechanism, the efficient, intelligent and reliable power distribution network-microgrid coordinated optimization scheduling method is provided, the defects of the prior art in the aspects of response speed, adjusting capacity and intelligent level are overcome, and the method has remarkable technical innovation and practical application value.

The invention discloses a bidirectional vehicle-mounted charging circuit and a circuit control method. The topology comprises a front-stage totem-pole bridgeless PFC and a rear-stage bidirectional CLLC converter; the bidirectional totem-pole bridgeless PFC converter is connected with a 220V single-phase power grid; the rear-stage bidirectional CLLC converter is connected with the bidirectional totem-pole bridgeless PFC converter; the forward resonance link and the reverse resonance link of the rear-stage bidirectional CLLC converter are the same so that soft switching can be achieved conveniently, and the rear-stage bidirectional CLLC converter is finally connected with the power battery of the electric vehicle and is combined with the front-stage totem-pole bridgeless PFC to charge the power battery. According to the invention, the vehicle-mounted charging circuit has G2V and V2G functions, the output voltage range is adjustable in a range of 300V-500V, and the applicability and the safety are improved.

The invention relates to a self-adaptive driving control method suitable for an H-bridge circuit. The method comprises the following steps: firstly, performing turn-off driving, and loading a target turn-off driving signal to a gate end of a target turn-off power tube based on turn-off information of the current target turn-off power tube so as to drive the target turn-off power tube to be gradually turned off based on the target turn-off driving signal; and when the turn-off information of the target turn-off power tube is at least in a pre-turn-off state, performing turn-on driving on a target turn-on power tube in the target turn-on bridge circuit tube group, and loading a target turn-on driving signal to the gate end of the current target turn-on power tube based on the turn-on state of the current target turn-on power tube so as to turn off the target turn-off power tube. And driving the current target conduction power tube to be gradually conducted based on the target conduction driving signal. Soft switching of the power tube in the H-bridge circuit is controlled, the working efficiency of the H-bridge circuit is improved, meanwhile, self-excitation resonance of the H-bridge circuit is prevented, and the dead time can change along with changes of external application conditions.

The invention relates to the field of active equalization of a series lithium ion battery pack, in particular to an equalization topological structure of a DC-DC multi-winding flyback battery equalization topological unit. Comprising an inversion unit, a multi-winding transformer and M battery equalization topology units. The voltage of the battery pack is used for supplementing electric energy to the under-voltage battery after passing through the converter, so that the aim of equalization is fulfilled. Compared with the existing flyback equalization technology, the switching frequency is improved to ultrahigh frequency of 10MHz, the equalization response speed is greatly improved, and meanwhile, the soft switching technology is adopted, so that the full-control switches are switched on in a zero-voltage manner, and the diodes are switched off in a zero-current manner. Along with the improvement of the switching frequency, the passive device can be reduced into a small-capacity patch package, for example, a planar air-core transformer can be adopted as a transformer, so that the power density is effectively improved. The circuit has the advantages of simple and reliable structure, fast response capability, few passive devices, small circuit loss, strong expansibility and stable output of direct current.

The invention discloses an excitation inductance design method for guaranteeing soft switching of a CLLC resonant converter, and the method comprises the steps: carrying out the qualitative analysis of a dead-zone equivalent circuit of the CLLC resonant converter, and carrying out the Laplace coordinate transformation. And according to the constant frequency analysis principle of the CLLC resonant converter, obtaining the electric quantity values of the capacitor and the inductor at the dead zone moment. And obtaining a resonance current time domain expression in a dead zone period by adopting a mesh current method. And calculating the period of the resonance current according to the parasitic capacitance values of the primary and secondary side switching tubes. And calculating the discharge time of the parasitic capacitor by considering the electric quantity of the capacitor. And calculating the excitation inductance value required when the resonance current just drops to zero when the dead time is ended. Soft switching of the resonant converter can be effectively guaranteed, the amplitude of the resonant current is reduced, the efficiency of the resonant converter is improved, and the universality is high.

The invention discloses a single-stage AC-DC converter soft switching modulation method based on frequency conversion, and belongs to the field of electronic power, and the method comprises the steps: selecting a full-bridge part of a single-stage AC-DC converter as a modulation mode of dual PWM and phase shift; circuit parameters, such as high-frequency frequency, inductance and the like, of rated working conditions are designed, and soft switching of all switches is achieved; and frequency conversion is adopted in a power frequency period, so that the maximum current ripple is reduced, and the efficiency is improved. Soft switching is realized through circuit parameters and a modulation method, and ripple minimization on the basis of soft switching is realized through a frequency conversion strategy; according to the method, control is simple, independent decoupling control for maintaining output power, alternating current sine output and bus voltage stability is achieved, and for application occasions pursuing high efficiency and high power density, the switching loss can be effectively reduced, the efficiency of the converter is improved, and meanwhile the operation stability and control accuracy of the converter are improved.

The invention discloses a high-efficiency single-stage bidirectional power conversion topological structure capable of realizing full-range soft switching and a control method of the high-efficiency single-stage bidirectional power conversion topological structure. In a single-stage bidirectional power conversion topology formed by double half bridges and a switch matrix, a controlled current source connected in parallel with a primary side of a second transformer is designed; the current on a bridge arm connected with the primary side of the second transformer can be effectively changed, so that the soft switching range of a switching tube on the bridge arm in a wide power transmission range is widened, and full-range soft switching in a power frequency period can be realized in any load range; the controlled current source is designed to only work before and after the switching moment of the primary side switching tube of the second transformer, the current stress of the switching tube can be effectively reduced, and meanwhile, the loss of the additional controlled current source is very small. According to the invention, the working range of the soft switching is widened, the additional loss caused by the soft switching is greatly reduced, higher efficiency and higher power density can be realized, and the cost advantage is realized.

The invention discloses an intelligent soft switching and multilayer electro-hydrogen hybrid energy storage two-stage space-time decoupling configuration method and system. The method comprises the following steps: inputting basic data and initializing network basic parameters; in the first stage of constructing the two-stage MEH-SOP model, the power / capacity of each device of the MEH is optimally configured on the basis of annual 8760h time sequence operation simulation considering time-of-use electricity price; constructing a second stage of the two-stage MEH-SOP model, extracting typical scenes of MEH full-year high-power charging / discharging and power distribution network full-year voltage serious out-of-limit, and optimally configuring SOP multi-port capacity; and solving the constructed two-stage MEH-SOP model, and outputting an optimal configuration result. According to the invention, a multi-level energy storage system covering from the day to the week is constructed, and the multi-port SOP direct current side is connected in a modularized manner, so that the structural flexibility and the operation flexibility of the power distribution network are remarkably enhanced.

The invention provides a modulation mode switching synchronous rectification soft switching buck type constant voltage power supply which comprises an input filter circuit, a power inductor L1, an output filter circuit, a main switch tube Q1, a synchronous rectification tube Q2 and a control circuit. The left end of the power inductor L1 is connected to the source electrode of the main switch tube Q1 and the drain electrode of the synchronous rectifier tube Q2, the right end of the power inductor L1 is connected to the positive electrode of the output capacitor, the drain electrode of the main switch tube Q1 is connected to the positive electrode of the input capacitor, and the source electrode of the synchronous rectifier tube Q2 is connected to a reference ground through a power inductor current sampling resistor RS1; and the control circuit respectively controls the on-off states of the main switch tube Q1 and the synchronous rectifier tube Q2 so as to realize zero-voltage conduction of the synchronous rectifier tube Q2. Through the characteristics of different modulation modes, light-load and heavy-load modulation mode switching and synchronous rectifier tube soft switching are realized, and the loss of the switching power supply under different conditions is reduced.

The application discloses a single-stage bidirectional power conversion topology structure capable of realizing wide-range soft switching and a control method thereof. The bridge-in and bridge-between phase shift control of a double half-bridge circuit and a high-frequency switch matrix provides a basis for realizing soft switching of all power tubes. The soft switching of a wide voltage variation range is realized by real-time adjustment of a switching frequency according to the size of a port voltage. The bridge arm current connected with the primary side of a second transformer is the sum of the primary side current of the second transformer and the inductance current connected with the primary side of the second transformer in parallel. By designing the inductance value of the parallel inductance connected with the primary side of the second transformer, the bridge arm current connected with the primary side of the second transformer can be effectively changed, so that the soft switching realization range of the switching tube of the bridge arm connected with the primary side of the second transformer under the wide power transmission range can be expanded.