Abstract: An efficient control method for an isolated multilevel DC/DC resonant converter achieves a wide output voltage range with a narrow device switching frequency range, relative to the output voltage range and the device switching frequency range of the prior art. At any given time, a control circuit selects one of three different modulation schemes to operate the primary-side switching devices of the resonant converter based on at least one of output voltage, output current, input signal, and one or more external control signals. Together with a selected device switching frequency, the three modulation schemes generate different voltage waveforms to a primary-side transformer, which are coupled to the secondary-side to provide different output voltages.

Abstract: A bidirectional DC-DC converter with three or more ports is described along with a method of operation thereof. The converter utilizes a common transformer for all ports and allows for power transfer from any port to any or all of the remaining ports. The converter may utilize a controller which implements variable-frequency control, delay-time control, and/or phase-delay control to achieve power transfer as desired between the converter ports. In some cases, power transfer between ports can operate similar to a series-resonant converter or a dual active bridge converter.

Abstract: A bidirectional DC-DC converter with three or more ports is described along with a method of operation thereof. The converter utilizes a common transformer for all ports and allows for power transfer from any port to any or all of the remaining ports. The converter may utilize a controller which implements variable-frequency control, delay-time control, and/or phase-delay control to achieve power transfer as desired between the converter ports. In some cases, power transfer between ports can operate similar to a series-resonant converter or a dual active bridge converter.

Abstract: A circuit technique substantially reduces the switching losses in an AC-DC power conversion system caused by turn-on characteristics of a main switch and the reverse-recovery characteristic of a rectifier. The losses are reduced by using an active soft-switching cell having a series inductor, a series capacitor, a main switch, a rectifier switch, and an auxiliary switch. The reverse-recovery related losses are reduced by the series inductor connected between the main and rectifier switches to control the rate of current change in the body diode of the rectifier switch during its turn-off. The main switch, the rectifier switch, and the auxiliary switch operate under zero-voltage switching (ZVS) conditions.

Abstract: A circuit technique substantially reduces the switching losses in an AC-DC power conversion system caused by turn-on characteristics of a main switch and the reverse-recovery characteristic of a rectifier. The losses are reduced by using an active soft-switching cell having a series inductor, a series capacitor, a main switch, a rectifier switch, and an auxiliary switch. The reverse-recovery related losses are reduced by the series inductor connected between the main and rectifier switches to control the rate of current change in the body diode of the rectifier switch during its turn-off. The main switch, the rectifier switch, and the auxiliary switch operate under zero-voltage switching (ZVS) conditions.

Abstract: An AC-DC power conversion system provides extended voltage gain characteristic by virtue of controlling a duty cycle of operation associated with the desired input-to-output gain. The AC-DC power conversion system includes an AC-stage, first and second inductors, first and second voltage-doubler stages, a totem-pole rectifier stage, and a DC-stage coupled across the totem-pole rectifier stage. Each voltage-doubler stage includes a first terminal, a second terminal, and a third terminal, wherein a first terminal of the AC-stage is coupled by the first inductor to the first terminal of each voltage-doubler stage and by the second inductor to the third terminal of each voltage-doubler stage. The totem-pole rectifier stage includes first and second terminals coupled, respectively, to the second terminal of the first voltage-doubler stage and the second terminal of the second voltage-doubler stage.

Abstract: A boost rectifier that operates with a single-phase input voltage includes (i) an input stage receiving the single-phase input voltage and including first and second input filter capacitors, (ii) a switching converter stage coupled to the input stage and including a rectification circuit and an inductor circuit, series-connected first and second switches providing a common terminal therebetween, and a phase output capacitor, (iii) an output stage that transfers energy stored in the phase output capacitor to an output load, (iv) a decoupling stage that provides high-impedance decoupling between the switching converter stage and the output stage, and (v) a control circuit configured to operate the first and second switches according to an output signal of a non-linear compensation circuit that combines a feedforward signal derived from both the input and output voltages of the boost rectifier with an output voltage feedback control signal.

Abstract: An AC-DC power conversion system provides extended voltage gain characteristic by virtue of controlling a duty cycle of operation associated with the desired input-to-output gain. The AC-DC power conversion system includes an AC-stage, first and second inductors, first and second voltage-doubler stages, a totem-pole rectifier stage, and a DC-stage coupled across the totem-pole rectifier stage. Each voltage-doubler stage includes a first terminal, a second terminal, and a third terminal, wherein a first terminal of the AC-stage is coupled by the first inductor to the first terminal of each voltage-doubler stage and by the second inductor to the third terminal of each voltage-doubler stage. The totem-pole rectifier stage includes first and second terminals coupled, respectively, to the second terminal of the first voltage-doubler stage and the second terminal of the second voltage-doubler stage.

Abstract: An efficient control method for an isolated multilevel DC/DC resonant converter achieves a wide output voltage range with a narrow device switching frequency range, relative to the output voltage range and the device switching frequency range of the prior art. At any given time, a control circuit selects one of three different modulation schemes to operate the primary-side switching devices of the resonant converter based on at least one of output voltage, output current, input signal, and one or more external control signals. Together with a selected device switching frequency, the three modulation schemes generate different voltage waveforms to a primary-side transformer, which are coupled to the secondary-side to provide different output voltages.

Abstract: A three-level modulation for an isolated multilevel DC/DC resonant converter offers output voltage regulation capability with fixed switching frequency and achieves high efficiency along with soft-switching of the power switches. The three-level modulation enables current balance in all power devices, therefore, realizes better thermal performance and longer circuit life. An efficient control method that combines the three-level modulation with conventional frequency modulation achieves a wide output voltage range with a narrow switching frequency range. At any given time, a control circuit selects one of two different modulation schemes to operate the primary-side switches of the resonant converter based on an output voltage, or to one or more external control signals. Together with a selected device switching frequency and duty cycles, the two modulation schemes generate different voltage waveforms to a primary-side transformer, which are coupled to the secondary-side to provide different output voltages.

Abstract: A three-level modulation for an isolated multilevel DC/DC resonant converter offers output voltage regulation capability with fixed switching frequency and achieves high efficiency along with soft-switching of the power switches. The three-level modulation enables current balance in all power devices, therefore, realizes better thermal performance and longer circuit life. An efficient control method that combines the three-level modulation with conventional frequency modulation achieves a wide output voltage range with a narrow switching frequency range. At any given time, a control circuit selects one of two different modulation schemes to operate the primary-side switches of the resonant converter based on an output voltage, or to one or more external control signals. Together with a selected device switching frequency and duty cycles, the two modulation schemes generate different voltage waveforms to a primary-side transformer, which are coupled to the secondary-side to provide different output voltages.

Abstract: A power supply includes power modules. Each of the power modules includes an input stage and an output stage. The input stage generates an intermediate voltage, and the output stage outputs a DC supply voltage according to the intermediate voltage. The input stages are controlled with at least one first common control signal having a common duty cycle, and the output stages are controlled with at least one second common control signal having a common duty cycle.

Abstract: A power supply includes power modules. Each of the power modules includes an input stage configured to convert an input voltage into an intermediate voltage, and an output stage configured to output a DC supply voltage according to the intermediate voltage. Input terminals of the input stages in the plurality of power modules are electrically connected in series, and the input stages are configured to be controlled with at least one first common control signal having a common duty cycle. Output terminals of the output stages in the plurality of power modules are electrically connected in parallel, and the output stages are configured to be controlled with at least one second common control signal having a common duty cycle. A method of supplying power is also disclosed herein.

Abstract: A power supply includes power modules. Each of the power modules includes an input stage and an output stage. The input stage generates an intermediate voltage, and the output stage outputs a DC supply voltage according to the intermediate voltage. The input stages are controlled with at least one first common control signal having a common duty cycle, and the output stages are controlled with at least one second common control signal having a common duty cycle.

Abstract: A power supply includes power modules. Each of the power modules includes an input stage configured to convert an input voltage into an intermediate voltage, and an output stage configured to output a DC supply voltage according to the intermediate voltage. Input terminals of the input stages in the plurality of power modules are electrically connected in series, and the input stages are configured to be controlled with at least one first common control signal having a common duty cycle. Output terminals of the output stages in the plurality of power modules are electrically connected in parallel, and the output stages are configured to be controlled with at least one second common control signal having a common duty cycle. A method of supplying power is also disclosed herein.

Abstract: A power module, which is connected to a power source, includes a rectifying unit, a filtering unit and an inverter. The rectifying unit has three legs. The filtering unit is connected to the rectifying unit, and the inverter is connected to the filtering unit. One of the three legs has two switching elements connected in series, and another one of the three legs has two rectifying elements connected in series. In addition, a power conversion apparatus including the power module is also disclosed.

Abstract: A multi-level voltage converter includes a multi-point converter circuit and at least one full bridge inverter circuit. The multi-point converter circuit is configured for converting a DC voltage into an intermediate multi-level voltage. The full bridge inverter circuit is electrically connected in series with the multi-point converter circuit and configured for receiving the intermediate multi-level voltage to generate a multi-level output voltage corresponding to a single phase output.

Abstract: A multi-level voltage converter includes a multi-point converter circuit and at least one full bridge inverter circuit. The multi-point converter circuit is configured for converting a DC voltage into an intermediate multi-level voltage. The full bridge inverter circuit is electrically connected in series with the multi-point converter circuit and configured for receiving the intermediate multi-level voltage to generate a multi-level output voltage corresponding to a single phase output.

Abstract: A power apparatus includes power modules. Each of the power modules includes an input transformer and power cell units. The input transformer has at least one primary winding and a plurality of secondary windings, and the primary winding is electrically connected to an AC power source. The power cell units are connected in series with one phase output line to a multi-phase load, in which the power cell units are electrically connected to the secondary windings, respectively.

Abstract: A power module, which is connected to a power source, includes a rectifying unit, a filtering unit and an inverter. The rectifying unit has three legs. The filtering unit is connected to the rectifying unit, and the inverter is connected to the filtering unit. One of the three legs has two switching elements connected in series, and another one of the three legs has two rectifying elements connected in series. In addition, a power conversion apparatus including the power module is also disclosed.