106 results about "Zero voltage switching" 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.

A two-transistor flyback topology in which a portion of leakage inductance energy in the transformer is extracted and used to obtain zero voltage switching on both switching elements in any operating conditions, and in which a third low power switch eliminates parasitic oscillations and allows an operation at a determined frequency. In this topology, there are no switching losses and there are no spikes or glitches in any switching node, eliminating the need for snubbers. This topology is an “ideal two transistor flyback topology.”

The invention discloses an extended double-side asymmetric phase shift modulation method for a dual-active bridge converter, and belongs to the technical field of isolated high-frequency power conversion in a power electronic technology. According to the symmetric phase shift modulation method, under the condition that the voltage conversion ratio is not matched, the zero voltage switching range of a switching tube is small, the light load efficiency is low, and variable abrupt change can occur during mode switching to cause the uncontrollable oscillation problem of inductive current. The invention provides an extended double-side asymmetric phase shift modulation method for a dual-active bridge converter in a wide voltage range. A multi-objective optimization scheme is established based on the provided modulation method, and an approximation method is provided to solve a full power range analytical solution. A smooth switching method between modes is realized, and uncontrollable oscillation of inductive current can be effectively avoided. And the conversion efficiency in a full-power range is improved.

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 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.

An example apparatus can include one or more of a transformer, a primary circuit electrically coupled to the transformer, and a first auxiliary circuit and a second auxiliary circuit, wherein the primary circuit includes a first bridge leg having a first pair of switches and a second bridge leg having a second pair of switches, the first auxiliary circuit is electrically coupled to the first bridge leg of the primary circuit, the second auxiliary circuit is electrically coupled to the second bridge leg of the primary circuit, wherein each auxiliary circuit is configured to store energy when one switch of a respective pair of switches is on and the other switch of the respective pair of switches is off, and provide the stored energy to recharge all attached capacitances in the respective bridge leg when both switches of the respective pair of switches are off.

The application discloses a resonant converter optimization method and system based on an fmincon function, which first determines transformer ratio and maximum and minimum values of converter output voltage DC gain; then converts an LLC resonant converter into an equivalent circuit, and deduces the converter output voltage DC gain as a first constraint condition; and establishes a converter loss model according to the equivalent circuit; analyzes the condition for realizing ZVS (Zero Voltage Switching) of a switching tube as a second constraint condition; finally, an optimization design function fmincon is called to perform optimization design on the resonant converter parameters. The loop power consumption of the converter is taken as an evaluation index for the resonant converter parameter design, the output voltage DC gain and the condition for realizing ZVS of the switching tube are taken as constraint conditions, the LLC resonant converter parameters are comprehensively evaluated, the LLC resonant converter parameters are obtained, which make all indexes of the converter reach the best balance, and the overall performance of the converter is effectively improved.

The application discloses a multi-path weak coupling wide voltage output DC-DC converter based on zero voltage switching, which comprises a direct current input power supply V in and N output branches, wherein N is a positive integer and N is greater than or equal to 2; the multi-path weak coupling wide voltage output DC-DC converter can realize good cross regulation among output ports by using a small number of elements, can realize both step-up output and step-down output, can meet different voltage demands, has a wide output voltage range, is easy to realize zero voltage switching, and thus can ensure high system efficiency; the multi-path output voltages can be respectively adjusted by independent control variables, and the cross coupling effect among the multiple output ports is effectively reduced.

According to one embodiment, a power amplifier includes a plurality of switches and an output tank network. One or more of the switches are configured to generate one or more first intermediate waveforms having one or more first fundamental frequency components, and one or more of the switches are configured to generate one or more second intermediate waveforms by chopping the one or more first intermediate waveforms with controllable timing. The second intermediate waveforms have one or more second fundamental frequency components that are controllably reduced from those of the one or more first intermediate waveforms. The output tank network is configured to filter the one or more second intermediate waveforms to provide an output waveform to a load, the output waveform having one or more third fundamental frequency components. In some cases, all switches achieve zero voltage switching under different power and load conditions with resistive and reactive loads.

The utility model discloses a resonant LLC switching power supply converter and a zero-voltage switch control circuit thereof, and the converter comprises a first switch module, a second switch module, a third switch module, a fourth switch module, a first capacitor module, a second capacitor module, a third capacitor module, an inductor module, and an isolation module. The zero-voltage switch control circuit comprises a reference voltage module, a current detection module, a first control module and a second control module, and the reference voltage module, the current detection module, the first control module and the second control module work cooperatively. The switching loss of the first switching module and the second switching module of the resonant LLC switching power supply converter is dynamically controlled and greatly reduced.

The application provides a mixed control LLC series resonant converter dead-time control method, which respectively calculates the current of phase leading and lagging bridge arm switch time and the shortest dead-time required for realizing ZVS (zero voltage switching), and uses a parameter fitting method to simplify the calculation amount, and controls the dead-time of two bridge arm switches in real time on an embedded controller. The application considers the different dead-time required for realizing zero voltage switching of the two bridge arm switches of the primary side of the mixed control LLC series resonant converter, and controls in real time, so that the primary side switch loses zero voltage switching due to working condition change is prevented, and the reverse conduction time of the switch is reduced as much as possible, and the loss is reduced. The application has good application effect in the mixed control LLC series resonant converter with high frequency and wide gain range.

A protection circuit of a resonant converter including first and second switches, where the protection circuit comprises: a comparator configured to (i) compare a direct current (DC) link voltage of the resonant converter with a voltage across both ends of one of the first or second switches and (ii) output one or more signals based on the comparison, and a microcomputer configured to detect whether zero voltage switching is performed, based on the one or more output signals from the comparator.

A system includes four primary side switches of a primary bridge of a dual active bridge (DAB) converter; four secondary side switches of a secondary bridge of the DAB converter; and a control circuit configured to operate the DAB converter in a first mode in which all of the four secondary side switches operate under zero voltage switching (ZVS) and less than all of the four primary side switches operate under ZVS; and in response to a thermal condition, operating the DAB converter in a second mode in which less than all of the four secondary side switches operate at the ZVS and all of the four primary side switches operate at the ZVS. A method includes operating a control circuit of an operating system to implement a first mode and a second mode. In some embodiments, the control circuit switches between a first mode and a second mode based on one or more thermal conditions.

A non-isolated DC-to-DC switching hybrid converter is implemented using a cross-coupled series-capacitor quadruple step-down buck converter topology. In some embodiments, the DC-to-DC switching hybrid converter includes a switched-capacitor converter circuit and incorporates a zero-voltage switching network to implement soft switching and a coupled inductor to realize a fixed step-down ratio. The hybrid converter is capable of supporting a high step-down ratio (such as 8:1) while providing high efficiency. In other embodiments, the DC-to-DC switching hybrid converter incorporates a transformer in place of the coupled inductor to further increase the step-down ratio.

Zero voltage switching with a secondary switch (e.g., a synchronous rectifier) is described herein. The method allows a secondary side controller to calculate a required secondary switch hold time. By measuring a forward pin voltage when the primary switch is conducting, the required secondary switch hold time may be determined without the need for primary to secondary communication.

The present invention discloses a control current and method for a zero-voltage switch, which utilizes a secondary-side feedback switching power supply auxiliary winding in combination with a PMOS tube to achieve the zero-voltage start-up function of the switching power supply. Compared with the existing technology, the circuit is relatively simple and has fewer circuit components, which is conducive to reducing the size of the charger and adapter.

The embodiment of the invention provides a flyback conversion circuit, a control method thereof and a control chip. The flyback conversion circuit comprises a primary side unit, a secondary side unit and an auxiliary unit, the primary side unit comprises a main switch tube and a primary side winding, the first end of the primary side winding is electrically connected with a power supply, the second end of the primary side winding is electrically connected with the first end of the main switch tube, and the second end of the main switch tube is electrically connected with reference ground; the secondary side unit comprises a secondary side winding; the auxiliary unit comprises an auxiliary switch tube, a first capacitor and an auxiliary winding; the first end of the auxiliary winding is electrically connected with the first end of the first capacitor, the second end of the first capacitor is electrically connected with the first end of the auxiliary switch tube, and the second end of the auxiliary switch tube is electrically connected with the second end of the auxiliary winding; the second end of the auxiliary winding is electrically connected with the reference ground; the second end of the primary winding, the first end of the auxiliary winding and the first end of the secondary winding are dotted terminals. The flyback conversion circuit can realize zero-voltage switching in different working modes, so that the working efficiency is improved.

The invention relates to an active clamping flyback converter and a control method thereof, and belongs to the field of flyback converters. According to the active clamping flyback converter, voltage stabilization of output voltage is achieved through a double-closed-loop control structure composed of a peak current mode loop and a dead time control loop, and the peak current mode loop is used for controlling the conduction time of a main switching tube. And the dead time control loop is used for detecting whether the active clamping flyback converter realizes a soft switching function or not. A double-loop control loop of a peak current mode and a dead time control mode is adopted, the problem that when the active clamping flyback converter is in light load, zero voltage switching is difficult to achieve in the first switching period, and additional loss is caused is solved, the cost of circuit design is effectively reduced, the occupied size is reduced, and the integration level is improved.

A switching mode power supply with zero voltage switching is discussed. It adopts a first secondary signal generator and a second secondary signal generator to control a secondary switch circuit to be turned on once again after a current freewheeling process is over.

The invention relates to the technical field of wireless charging, in particular to a wireless charging control system and method based on soft switching, and the system comprises a data collection module which scans load identification information through a near field communication unit, and a parameter calculation module which calculates a frequency control instruction and the number of parallel modules according to a pre-stored voltage gain mapping relation. The control signal generation module is used for generating a PWM driving signal, the power transmission module comprises a single-tube inverter circuit and a magnetic coupling structure, and the soft switching monitoring module is used for collecting voltage and current waveforms of a switching tube and judging a soft switching state. Through a modularized closed-loop control architecture, the voltage sine of a switching tube is attenuated to zero by using a resonance network in the turn-off stage of an MOSFET, so that a zero-voltage switching condition is realized, the switching loss and thermal stress are effectively reduced, the system efficiency is improved, and power expansion is supported.

The utility model relates to the technical field of semiconductor device especially is a kind of GaN device zero-voltage switch control device, including zero-voltage switch control circuit board and GaN chip main part, zero-voltage switch control circuit board upper end fixed mounting has GaN chip main part, zero-voltage switch control circuit board inside plug-in installation has wiring terminal, wiring terminal includes compression type wiring terminal shell, compression type wiring terminal shell bottom end is fixedly connected with pin, compression type wiring terminal shell inside spiral connection has screwing pressure subassembly, compression type wiring terminal shell inside installation has moving assembly, compression type wiring terminal shell inside fixedly connected with guide tube, compression type wiring terminal shell inside slidingly connected with moving plate, in the utility model, device has realized to the three-dimensional wrapping formula fixing of wire, anti-skid groove on pressure disc and anti-rotation groove on pressure block can effectively suppress the radial displacement and radial rotation of wire under high-frequency vibration environment, prevent wire from sliding from wiring terminal.

A controller for a power converter includes a primary controller and a secondary controller. The primary controller is coupled to a primary winding of the energy transfer element and a primary switch of the power converter. The secondary controller is coupled to a secondary winding of the energy transfer element and a secondary switch, e.g., a synchronous rectifier, of the power converter. The secondary controller has a synchronous rectifier control / drive circuit, a control logic circuit, and a cross conduction detector circuit. Cross conduction is when the primary switch turns on when the secondary switch is active. The cross-conduction detector circuit produces a Disable SR signal when cross conduction event detected. The cross-conduction detector circuit detects zero voltage switching cross conduction event and a minimum conduction period cross conduction event. The SR drive circuit disables the synchronous rectifier in response to receiving the Disable SR signal.

A method comprises: in an onboard charger of an electric vehicle, providing i) a direct current (DC) to DC stage including a dual-active bridge, and ii) a DC link capacitor having a DC bus voltage; and dynamically regulating the DC bus voltage to improve zero voltage switching (ZVS) in the onboard charger.

The invention discloses a magnetic switch zero-current connection auxiliary circuit for reducing switching loss of a pulse generator. The magnetic switch zero-current connection auxiliary circuit comprises a magnetic switch MS, a load RL, an energy storage capacitor Cdc, a direct-current input voltage source Vdc and a driving switch. The single saturable magnetic core is used for achieving current phase regulation and control, a complex topological structure is replaced, the system architecture is simplified, the waveform rising edge is steeped, and waveform distortion is small. According to the invention, the slope of a voltage falling edge is directly optimized through driving resistance adjustment, and zero voltage switching (ZVS) is realized under the condition that an auxiliary resonance circuit or a high-frequency driving chip is not needed. A matching mechanism of the magnetic core saturation threshold value and the load voltage is established, and the soft switching adaptability in a wide load range is ensured. The magnetic switch zero-current connection auxiliary circuit provided by the invention has strong load adaptability, and shows excellent switching loss reduction capability in a range from light load to heavy load.

A method comprises: providing, in an onboard charger of an electric vehicle, a direct current (DC) to DC stage including a dual-active bridge having switches arranged in multiple legs, each of the multiple legs controlled by a corresponding one of pulse width modulation (PWM) signals; and dynamically modulating the PWM signals to improve zero voltage switching (ZVS) in the onboard charger.

A half-bridge flyback converter and a control method thereof. The half-bridge flyback converter includes a first transistor, a second transistor and a third transistor, wherein the first transistor, the second transistor and the third transistor are used to constitute a half-bridge circuit. The first transistor is turned on to generate a negative circulating current to achieve zero voltage switching of the second transistor. The second transistor is turned on to excite a transformer. The third transistor is turned on in a demagnetization period of the transformer to generate an output voltage. The actual size of the first transistor is smaller than the actual size of the third transistor.

The present invention discloses a circuit adaptive zero-voltage switching control method based on electroluminescence of a switching tube, an electroluminescence detection circuit and its module structure. The adaptive zero-voltage switching control method uses the electroluminescence effect to detect the switching state and autonomously control the gate switch of the device. The method effectively realizes adaptive zero-voltage switching operation under both steady-state and transient load conditions. The detection circuit uses two signal receiving and amplifying components in a differential mode to improve the signal-to-noise ratio of the electroluminescence detection circuit with ultra-high amplification gain. The first silicon photomultiplier tube of the first signal receiving and amplifying component is placed close to the bare chip of the switching tube to be detected in the embedded printed circuit board power module, and is used to sense the electroluminescence of the bare chip of the switching tube; the second silicon photomultiplier tube of the second signal receiving and amplifying component is located outside the electroluminescence transmission area to eliminate potential noise caused by ambient light and electromagnetic interference.

The application discloses a continuous mode bridgeless power factor correction circuit and a control method thereof, which comprises an alternating voltage source AC, a diode D1, a diode D2, a main switch Q1, a main switch Q2, an output capacitor C1, a positive half cycle control circuit and a negative half cycle control circuit. In the application, the freewheeling diode is reversely biased before the main switch is turned on, and the current is transferred to the control circuit auxiliary super-fast diode branch. The body diode of the freewheeling diode has no reverse current when the main switch is turned on, and can work at high frequency. Through proper dead zone setting, the freewheeling diode can realize zero voltage switching. The control circuit only works for a short time, the control method is simple, the average power is small, and the cost is low.

Systems and methods for operating a wireless power transfer device are described. A circuit can generate a first signal that indicates a voltage at a node between a first high-side (HS) transistor and a first low-side (LS) transistor in a switching converter falling below ground. The circuit can delay a gate-source voltage of a second LS transistor in the switching converter to generate a second signal. The circuit can merge the first signal and the second signal to generate a third signal. A controller can use the third signal to trigger a rising edge of a command signal to turn on the first LS transistor at a specific time. The first LS transistor being turned on at the specific time reduces a diode conduction time of a body diode of the first LS transistor.

The invention relates to dual active bridge parameter estimation for control configuration. Systems and methods for operating a dual active bridge (DAB) converter include a transformer flowing a current through the DAB converter; measuring the current; determining a leakage inductance of the transformer based on the measured current; and determining a control scheme for operating the DAB converter based on the leakage inductance of the transformer. In some embodiments, determining the leakage inductance includes determining a slot resistance of the transformer. In some embodiments, the control scheme includes a gain scheduling, zero voltage switching scheme, or both, where the control scheme is different from a nominal control scheme based on nominal leakage inductance and improves power conversion efficiency or accuracy of the output voltage compared to the nominal control scheme.