309 results about "Synchronous rectifier" patented technology

System and method for controlling synchronous rectification. For example, a system for controlling synchronous rectification includes: a first control-signal generator configured to generate a first control signal; a second control-signal generator configured to receive the first control signal for a first switching cycle and generate a second control signal for a second switching cycle based at least in part on the first control signal for the first switching cycle, the first switching cycle preceding the second switching cycle; and a driver configured to receive the first control signal and generate a drive voltage based at least in part on the first control signal; wherein the second control-signal generator is further configured to: process information associated with the first control signal; determine a first time duration when the first control signal remains at a first logic level during the first switching cycle.

A flyback converter to receive an input voltage and provide an output voltage is provided, and may include a transformer having a primary winding and secondary winding, a primary switch coupled to the primary winding, a synchronous rectifier device coupled to the secondary winding, and a secondary side control circuit to turn on the synchronous rectifier device by outputting a control signal at a first amplitude, subsequently modify the control signal to maintain a voltage across the synchronous rectifier device substantially constant until a predicted time that precedes a current in the synchronous rectifier device reaching substantially zero, subsequently turn off the synchronous rectifier device based on the voltage across the synchronous rectifier device reaching substantially zero, and subsequently turn on the synchronous rectifier device by outputting the control signal at a second amplitude, before the primary switch is turned on. The second amplitude is less than the first amplitude.

The present invention provides a control circuit of an isolated power supply and an isolated power supply. A secondary side controller in the control circuit can turn on and off a synchronous rectifier based on a voltage from a secondary side winding, enabling adaptive turn-on and turn-off control of the synchronous rectifier. Specifically, when the voltage from the secondary side winding reaches a second predetermined voltage, an instruction for turning off the synchronous rectifier is provided. The second predetermined voltage is adjusted based on a comparison between a time interval for the previous switching period and a predetermined reference interval. In this way, a delay from a turn-off time of the synchronous rectifier to a turn-on time of a primary transistor switch is substantially maintained at the predetermined reference interval. This prevents cross-conduction of the primary and secondary side circuits, ensuring safe operation of the isolated power supply.

The embodiments of the present disclosure provide a synchronous rectifier module, comprising: a transformer provided with a plurality of secondary windings, a first circuit board and a second circuit board disposed on opposite sides of the transformer, and a first connecting piece electrically connected to the first circuit board and a second connecting piece electrically connected to the second circuit board; the first connecting piece and the second connecting piece comprise current sharing portions connected to the first circuit board and the second circuit board respectively, and inductor portions which penetrate an inductance core side by side to form an output inductor, resistance values of the current sharing portions of the first connecting piece and the second connecting piece being equal or a resistance difference value therebetween being within a preset range. The present disclosure can quickly, accurately and conveniently improve the efficiency and the heat dissipation of the synchronous rectifier module, and achieve a better current sharing effect of the connecting pieces by adjusting the resistance value numerical range of the two connecting pieces.

The invention discloses a topological structure of a single-phase isolation type integrated vehicle-mounted charging system without an electrolytic capacitor and a control method of the topological structure, the system multiplexes a driving motor stator winding on the basis of an open winding driving system of an electric vehicle, and when the system is switched from a driving operation mode to a charging operation mode, the driving motor stator winding is switched to the charging operation mode. An open winding permanent magnet motor driving system is reconstructed into an isolated AC / DC converter without an electrolytic capacitor through a change-over switch, the isolated AC / DC converter comprises a synchronous rectifier, a dual-active-bridge converter and an active filtering device, phase shifting is controlled through matching of transmission power and network side input power, power factor correction is achieved, and power factor correction is achieved through winding inductive current control. According to the vehicle-mounted power battery integrated vehicle-mounted charging system, the inherent secondary power pulsation is filtered out to realize active filtering, and the torque pulsation suppression of a multiplexing motor winding is realized through a magnetic flux balance method, so that the vehicle-mounted power battery integrated vehicle-mounted charging system with an isolation charging characteristic is obtained, the integrated design of a driving charging function is realized, and the reliability and the safety of the integrated charging system are improved.

A magnetic inductive resonance charging circuit includes a resonant network having an inductive secondary coil that converts a magnetic field received from an inductive primary coil into an alternating current (AC) signal and a synchronous rectifier that rectifies the AC signal to generate a direct current (DC) signal for application to a load. The synchronous rectifier includes a variety of configurations for shunting the AC waveform of an AC current source in the event of a fault. For example, a rectifier controller may hold a pair of normally open switches of the rectifier off and a pair of normally closed switches of the rectifier on to shunt the AC current source when an over-voltage, over-current fault condition or an over-temperature fault condition is detected. Configurations are provided for grounding the capacitive electromagnetic interference produced in the chassis of an electric vehicle when the resonant network is unbalanced.

A control circuit and method for an isolated switching-mode converter are disclosed. In the control circuit, in preparation for turning on a primary transistor switch in a primary-side circuit, preferably, a secondary-side controller transmits an inquiry signal to a primary-side controller, and the primary-side controller transmits, after confirming that it has been prepared, a feedback signal to the secondary-side controller to allow the secondary-side controller to confirm that the primary transistor switch has been turned off. After that, the primary-side controller turns on the primary transistor. In other words, in the control circuit and method of the present invention, in preparation for turning on the primary transistor switch, information exchange is conducted between the primary and secondary sides to make sure that the primary transistor switch is turned on after the synchronous rectifier transistor is turned off.

The invention discloses a bidirectional six-switch buck-boost topology circuit and a control method thereof, and belongs to the technical field of power electronics. According to the scheme, two switch tubes and one inductor are additionally arranged on the basis of a four-switch buck-boost circuit, and an input negative electrode and an output negative electrode are separated through the additionally arranged switch tubes and inductor, so that the problem that when different input source outputs are connected in parallel, a negative bus is directly connected to form circulating current is effectively solved; a loop does not need to judge an input and output voltage relation, the duty ratio of a power switch tube is automatically adjusted directly according to the set voltage, current and energy transfer direction, and the boost-buck state of the topology is determined according to the calculation result of the duty ratio, so that the control on the energy transfer direction is realized; the on / off of the synchronous rectifier tube is determined by the magnitude of the output current. By adopting the scheme of the embodiment of the invention, the circulating current problem caused by multi-path input difference can be solved, the topology control difficulty is reduced, and the control error-tolerant rate is improved.

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 invention relates to an LLC resonant soft switching converter based on self-detection synchronous rectification and a control method thereof. The converter comprises an LLC resonance circuit, a secondary transformer with a center tap, a self-detection synchronous rectification circuit, an input filter circuit, an output filter circuit, an LLC resonance control circuit, a primary PFM drive circuit, an optocoupler isolation circuit, an output voltage sampling circuit and an operational amplifier compensation circuit. Switching tubes S1 and S2 in the primary PFM drive circuit adopt high-voltage MOS tubes, secondary synchronous rectifier tubes S3 and S4 adopt low-voltage MOS tubes, output voltage feedback control and secondary synchronous rectifier tube self-detection drive control are adopted, and the resonant soft switching converter with the 240V-300V input voltage range, the constant output of 28V / 300W and the full-load efficiency of 92% is realized. According to the invention, zero-voltage switching-on of the primary switch tube, zero-current switching-off of the secondary synchronous rectifier tube and accurate synchronous rectification control are realized, the loss of the rectifier circuit is reduced, the efficiency of the converter is improved, and the electromagnetic compatibility characteristic of the converter is optimized.

A power converter incorporating a synchronous rectifier implements adaptive turn-off voltage control for fast turn-off of the synchronous rectifier in the continuous conduction mode. In some embodiments, the synchronous rectifier turn off detection threshold is adaptively changed as a function of the detected operation mode of the power converter. In response to detecting the power converter being operated in the continuous conduction mode, the synchronous rectifier turn off detection threshold is set to a voltage value farther away from zero volt as compared to the nominal turn off detection threshold. In this manner, the synchronous rectifier can be turned off earlier while in the continuous conduction mode. When the synchronous rectifier can be turned off quickly, large reverse current or negative current as well as large drain voltage spike at the synchronous rectifier can be avoided. The reliability of the synchronous rectifier and the power converter is improved.

The utility model provides a flyback converter and a primary state detection circuit thereof, in a detection interval, when a drain terminal voltage of a synchronous rectifier is greater than an output voltage, integration is carried out from zero based on a difference value between the drain terminal voltage and the output voltage to obtain a first volt-second integral; the volt-second integral judgment module compares the first volt-second integral with a preset integral threshold value and outputs a first judgment signal; the pulse signal generation module generates a first short pulse signal and a second short pulse signal at the starting moment and the ending moment of a detection interval respectively; the pulse counting module counts pulses based on the first judgment signal, the first short pulse signal and the second short pulse signal and outputs a first count value; the synchronous rectifier driving control module judges that the flyback converter primary stage is in a fault state based on the first count value; and when the flyback converter is in the primary fault state, stopping driving the synchronous rectifier. By means of the arrangement, when the primary stage breaks down, the common phenomenon of the primary stage and the secondary stage can be avoided.

The invention provides a control method for suppressing light-load turn-off stress of a synchronous rectifier tube. The control method comprises the following steps: determining a control module setting end level based on a preset high-level threshold voltage and a control module setting end voltage; receiving a power supply fault signal, and determining a control module data end level based on the power supply fault signal; receiving a clock signal, and determining the driving end level of the control module based on the clock signal; determining a control module output end level based on the control module data end level, the control module driving end level and the control module setting end level so as to generate a PWM closing signal based on the control module output end level; and controlling the main control module to close PWM output at a preset safety moment based on the PWM closing signal, thereby realizing suppression of the turn-off stress of the synchronous rectifier tube. According to the control method and circuit for suppressing the light-load turn-off stress of the synchronous rectifier tube, the power supply fault signal and the clock signal are combined to control the main control module to turn off PWM output at the safe moment, and the stress problem of the synchronous rectifier tube is avoided.

The invention discloses a double-half-bridge direct-current converter integrated structure. Comprising an input direct-current power supply Vin, a first switch tube S1, a second switch tube S2, a third switch tube S3, a fourth switch tube S4, a first resonance unit circuit, a second resonance unit circuit, a transformer T, a first synchronous rectifier tube SR1, a second synchronous rectifier tube SR2, a third synchronous rectifier tube SR3, a fourth synchronous rectifier tube SR4, a first output filter capacitor Co1 and a second output filter capacitor Co2, the transformer T comprises a first primary winding PT1, a second primary winding PT2, a first secondary winding ST1, a second secondary winding ST2, a third secondary winding ST3 and a fourth secondary winding ST4. Full-period work of the transformer winding is achieved, the winding utilization rate is high, the shortest alternating current path, high efficiency and high power density of the winding are achieved, winding loss and the occupied area are effectively reduced, control is easy, reliability is high, and implementation is easy.

The invention belongs to the technical field of planar transformers, and relates to a fractional-turn planar transformer of a matrix type integrated structure and a converter. Comprising M magnetic cores and a PCB (printed circuit board), and each magnetic core is provided with a plurality of layers of primary windings and N sections of secondary windings; a circuit structure is arranged between the secondary winding on the first surface and the secondary winding on the second surface, and a source electrode of a synchronous rectifier tube in the circuit structure is connected with a grounding end of an output capacitor; positive potential ends, back to two output capacitors in the circuit structure, on the first surface and the second surface are connected; according to the planar transformer, the advantages of the fractional turn scheme and the matrix scheme of the existing planar transformer are combined, the defects of the fractional turn scheme and the matrix scheme are suppressed, and the requirements of the market for the high-transformation-ratio transformer on the higher server power supply bus voltage are met.

A battery pack charger having housing including a battery pack interface for removably receiving a battery pack and a power input. The battery pack charger including a hybrid flyback converter having a primary side including a DC-DC half-bridge and a secondary side including a synchronous rectifier. The hybrid flyback converter is electrically connected between the power input and the battery pack interface and is configured to provide charging power from the power input to the battery pack interface.

The invention provides a processing method and device of a synchronous rectification driving circuit and a resonant converter, and relates to a synchronous rectification driving technology, and the method comprises the steps: obtaining a primary side driving signal for a primary side switching tube in a primary side circuit through a main control circuit; and acquiring a driving protection signal corresponding to the corresponding synchronous rectifier tube based on the primary side driving signal for one path of primary side switch tube. And a self-driven driving signal corresponding to the corresponding synchronous rectification tube is obtained through the synchronous rectification driving circuit. Generating a synchronous rectifier tube driving signal according to the driving protection signal and the self-driving signal; and controlling the on and off of the corresponding synchronous rectifier tube according to the synchronous rectifier tube driving signal. According to the method, the synchronous rectifier tube is turned off in time, direct connection of the upper and lower synchronous rectifier tubes of the synchronous rectifier circuit and short circuit of the secondary side of the transformer caused by drive delay turn-off are avoided, and the problem of drive direct connection of the upper and lower tubes of the synchronous rectifier tube is solved.

The invention provides a flyback converter and a control circuit and a control method thereof, and the control circuit comprises a primary side control circuit which is used for controlling the on and off of a main power tube; the secondary side control circuit is used for controlling the switch-on and switch-off of the synchronous rectifier tube so as to control the first time of switch-on of the synchronous rectifier tube before the excitation current of the flyback converter reaches a zero crossing point for the first time and the second time of switch-on of the synchronous rectifier tube after zero crossing of the excitation current, and the secondary side control circuit determines second time according to a preset volt-second reference and the output voltage of the flyback converter. According to the invention, the extra turn-on pulse width of the synchronous rectifier tube is set in a volt-second integration mode, the magnitude of the negative excitation current can be controlled, negative current sampling during zero voltage turn-on is facilitated, and meanwhile, zero voltage turn-on in a full input voltage range can be realized to the greatest extent, so that the system efficiency is improved.

This disclosure presents an embodiment of a power supply device for a submarine data center. One specific embodiment of the power supply device includes a pre-stage voltage regulator / conversion component, a post-stage DC-DC converter component, and a combined protection circuit. The pre-stage voltage regulator / conversion component includes several parallel single-group voltage regulator branches, each branch connected in series with a varistor and a color-coded resistor. A thin-film capacitor is connected in parallel to the output terminal of the pre-stage voltage regulator / conversion component. The post-stage DC-DC converter component, electrically connected to the pre-stage voltage regulator / conversion component, includes at least two sets of full-bridge DC synchronous rectifier circuits. The combined protection circuit includes a pre-stage combined protection circuit, a post-stage active voltage clamping circuit connected in parallel to the output side of the post-stage DC-DC converter component, and a rectifier diode bridge connected between the constant current input port and the pre-stage voltage regulator / conversion component. The pre-stage combined protection circuit is connected in series to the input side of the rectifier diode bridge. By connecting multiple voltage regulator branches in parallel and combining them with the combined protection circuit, ripple is reduced. This embodiment can improve the power supply stability of the power supply device.

A power converter can include: M transformer units, each including primary and secondary windings; M bridge arms, each being is coupled between two input terminals of the power converter to receive a DC input voltage, and each bridge arm comprises a high-side switch, a low-side switch, and a synchronous rectifier coupled in series; where a first terminal of each of the primary windings is coupled to a common node between the high-side switch and the low-side switch in one of the M bridge arms, and a second terminal of each primary winding is coupled together; and where one terminal of each of the secondary windings is coupled to a common node between the low-side switch and the synchronous rectifier in one of the M bridge arms, and the other terminal of each of the secondary windings is coupled to a first output terminal of the power converter.

An electronic rectifier circuit for adaptive gate voltage regulation of a synchronous rectifier field-effect transistor is provided, the electronic rectifier circuit is configured to clamp a drain-source voltage of the SR FET to a first regulation voltage while the SR FET is switched on for less than a threshold time in a current switching cycle, and the electronic rectifier circuit is configured to clamp the Vds of the SR FET to a second regulation voltage while the SR FET is switched on for more than the threshold time in the current switching cycle, the threshold time is configured as a portion of time that the SR FET was switched on in one or more previous switching cycles, and Vreg2 is smaller than Vreg1.

A secondary side controller for an AC-DC converter, the secondary side controller having a single synchronous rectifier sense (SR_SNS) terminal coupled to a synchronous rectifier (SR) of the AC-DC converter, and a voltage divider circuit coupled to the single SR_SNS terminal, the voltage divider circuit configured to provide a signal to a sense circuit. The voltage divider includes an active diode, an internal resistive element, and a switch, wherein the active diode is configured to control the switch to enable or disable the internal resistive element based on a comparison of a voltage at the single SR_SNS terminal to a reference voltage.

The application relates to a critical conduction mode control method of a totem-pole PFC converter, which utilizes energy equivalence to determine the resonance process of inductor current at switching commutation, carries out totem-pole Boost inductor current value estimation, and on this basis, utilizes a current zero-crossing point prediction algorithm to calculate the turn-on and turn-off time to generate corresponding active tube-synchronous rectifier tube commutation dead time T d,f , synchronous rectification conduction time T SR , rectifier tube-active tube commutation dead time T d,r ; the PWM drive signals of high-speed switching tubes Q1 and Q2 are generated by T on , T d,f , T SR , T d,r ; the power frequency drive signals of low-speed switching tubes Q3 and Q4 are generated by comparing the input alternating voltage v ac with a hysteresis comparison loop and 0. The method can effectively get rid of the dependence on a current zero-crossing detection circuit and a current sensor, reduces the cost and improves the system stability.

The application belongs to the technical field of digital signal processing, and particularly discloses a digital signal generation and processing method and system for synchronous rectification, wherein the method comprises the following steps: obtaining the staggered sampling code stream of a synchronous rectification device, and outputting time-aligned voltage and current characteristic values after group delay hard compensation; performing polynomial thermodynamic school correction in combination with discrete shell temperature sampling values; performing physical safety working area boundary checking on the corrected characteristic values, addressing and interpolating output of the target optimal conduction timing value in the irregular lattice space; extracting a feature vector to perform recursive least square prediction, and outputting an overshoot prediction extreme value; performing discrete charge integration in combination with a nonlinear capacitance function, and iteratively outputting a target dead time value based on the charge conservation criterion; and the application has the advantages of accurate control timing, physical boundary safety and dead time self-adaptation.

This application provides a multi-output flyback converter and power supply system, relating to the field of power supply technology. The multi-output flyback converter includes a control module, a transformer, a primary-side switching module, and multiple synchronous rectifier modules. The primary-side switching module is connected to the primary winding of the transformer, and each synchronous rectifier module is connected to each secondary winding of the transformer. Each synchronous rectifier module includes two back-to-back connected switching transistors. The control module is connected to the control terminals of the primary-side switching module, the control terminals of the two switching transistors in each synchronous rectifier module, and the output terminal of each synchronous rectifier module. The control module is used to adjust the duty cycle of the primary-side switching module according to the actual output voltage of the actively regulated output path; and to adjust the duty cycle of the switching transistors in each non-actively regulated output path according to the actual output voltage of each non-actively regulated output path, thereby eliminating cross-regulation between the outputs.

Systems for power conversion, and controllers and methods for operating a power converter. The method includes receiving high-side and low-side primary signals that drive primary transistors of a power converter. The method also includes receiving a combined drain voltage signal for high-side and low-side synchronous rectifier (SR) transistors of the power converter. The method further includes generating a high-side SR signal based on the low-side primary signal and generating a low-side SR signal based on the high-side primary signal. The method also includes determining high-side and low-side body diode conduction times based on the combined drain voltage signal. The method further includes adjusting the high-side SR signal based on the high-side body diode conduction time and adjusting the low-side SR signal based on the low-side body diode conduction time.

To provide a DE class inverter, a DE class synchronous rectifier circuit, and a non-contact power supply system that can perform an ideal and highly efficient operation, even when a load resistance value fluctuates.SOLUTION: An inverter 2 includes a passive circuit 20 between a switching circuit 11 and a load 5 for converting an input impedance Z to output of the switching circuit 11. The passive circuit 20 converts the input impedance Z into a reference impedance Z0 when the load 5 has a predetermined resistance value Rl0, with the input impedance Z being a reference impedance Z0 when switching voltages of a first switching element 12 and a second switching element 13 achieve ZVS and ZVDS during a time length τ of a dead time, and converts the input impedance Z to be within a range in which the switching voltage achieves ZVS during the time length τ of the dead time when the resistance value Rl of the load 5 varies from the predetermined resistance value Rl0.SELECTED DRAWING: Figure 2

The present invention relates to the field of power electronic converter control, aiming to provide a converter and its control method for achieving the optimal efficiency of a hydrogen production system. The converter is connected to a three-phase AC power supply and an electrolytic cell, and is an isolated AC / DC converter composed of two-stage converters, including a three-phase power correction rectifier module and a phase-shifted full-bridge module that are electrically connected in sequence, and an electrolytic capacitor is provided between the two modules; wherein, the three-phase power correction rectifier module is composed of six switching tubes, and the switching tubes are interconnected to form three H-bridge structures; the phase-shifted full-bridge module includes a DC / AC sub-module and an AC / DC sub-module; wherein, the DC / AC sub-module includes a primary H-bridge composed of four switching tubes; the AC / DC sub-module is located on the secondary side of the transformer and includes a synchronous rectifier switching tube and an inductor-capacitor filter circuit, and its output terminal is connected to the electrolytic cell. The present invention has the advantages of low switching loss and wide load voltage regulation range, and can meet the requirements of the hydrogen production system.

The present invention discloses a two-output charging circuit and a method for controlling its auxiliary circuit switch. The two-output charging circuit includes two first-stage switch transistors in the half-bridge inverter circuit generating dead time at changing-over and turn-on, and the second-stage switch transistor being turned off within the dead time. In the present invention, making use of a magnetic core to return from the reverse in its bidirectional magnetization process generates dead time, and controlling the time sequence of the switch device of the post-circuit in the dead time abates the voltage stress of the synchronous rectifier diode and reduces the loss of the absorption circuit of the synchronous rectifier circuit.

The present invention discloses a synchronous rectification method and device, including: Step S1, obtaining the resonant current in the charge control circuit of an LLC resonant converter; Step S2, obtaining the magnetizing current in the charge control circuit of the LLC resonant converter; Step S3, obtaining a drive signal applied to a synchronous rectifier tube according to the resonant current and the magnetizing current. By adopting the technical solution of the present invention, the problem that it is difficult to determine the drive signal of the synchronous rectifier tube in a charge control type resonant converter is solved, and at the same time, the problems that the cost of using a synchronous rectification chip is high and it is difficult to achieve multi-degree-of-freedom phase-shift control are solved.