Abstract: The present disclosure provides a three-phase AC/DC converter aiming for low input current harmonic. The converter includes an input stage for receiving a three-phase AC input voltage, an output stage for at least one load, and one or more switching conversion stages, each stage including a plurality of half bridge modules. The switches in each module operate with a substantially fixed 50% duty cycle and are connected in a specific pattern to couple a DC-link and a neutral node of the input voltage. The AC/DC converter further includes one or more controllers adapted to vary the switching frequency of the switches in the switching conversion stages based on at least one of load voltage, load current, input voltage, and DC-link voltage. The converter can also include one or more decoupling stages, such as, inductive components adapted to decouple the output stage from the switching conversion stages.

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 power converter and a control method thereof are provided. The power converter includes a primary side switching circuit, a secondary side switching circuit, a transformer, and a control circuit. The primary side switching circuit includes a first set of switches. The secondary side switching circuit includes a second set of switches. The transformer is coupled between the primary side switching circuit and the secondary side switching circuit. The control circuit is configured to control power transfer between the primary side switching circuit and the secondary side switching circuit by controlling the first and second sets of switches. The control circuit is adapted to enable and disable the first and second sets of switches in an enabling duration and a disabling duration respectively and alternatively.

Abstract: The present disclosure provides a three-phase AC/DC converter aiming for low input current harmonic. The converter includes an input stage for receiving a three-phase AC input voltage, an output stage for at least one load, and one or more switching conversion stages, each stage including a plurality of half bridge modules. The switches in each module operate with a substantially fixed 50% duty cycle and are connected in a specific pattern to couple a DC-link and a neutral node of the input voltage. The AC/DC converter further includes one or more controllers adapted to vary the switching frequency of the switches in the switching conversion stages based on at least one of load voltage, load current, input voltage, and DC-link voltage. The converter can also include one or more decoupling stages, such as, inductive components adapted to decouple the output stage from the switching conversion stages.

Abstract: A power converter and a control method thereof are provided. The power converter includes a primary side switching circuit, a secondary side switching circuit, a transformer, and a control circuit. The primary side switching circuit includes a first set of switches. The secondary side switching circuit includes a second set of switches. The transformer is coupled between the primary side switching circuit and the secondary side switching circuit. The control circuit is configured to control power transfer between the primary side switching circuit and the secondary side switching circuit by controlling the first and second sets of switches. The control circuit is adapted to enable and disable the first and second sets of switches in an enabling duration and a disabling duration respectively and alternatively.

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: The present disclosure provides a three-phase AC/DC converter aiming for low input current harmonic. The converter includes an input stage for receiving a three-phase AC input voltage, an output stage for at least one load, and one or more switching conversion stages, each stage including a plurality of half bridge modules. The switches in each module operate with a substantially fixed 50% duty cycle and are connected in a specific pattern to couple a DC-link and a neutral node of the input voltage. The AC/DC converter further includes one or more controllers adapted to vary the switching frequency of the switches in the switching conversion stages based on at least one of load voltage, load current, input voltage, and DC-link voltage. The converter can also include one or more decoupling stages, such as, inductive components adapted to decouple the output stage from the switching conversion stages.

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 power converter and a control method thereof are provided. The power converter includes a primary side switching circuit, a secondary side switching circuit, a transformer, and a control circuit. The primary side switching circuit includes a first set of switches. The secondary side switching circuit includes a second set of switches. The transformer is coupled between the primary side switching circuit and the secondary side switching circuit. The control circuit is configured to control power transfer between the primary side switching circuit and the secondary side switching circuit by controlling the first and second sets of switches. The control circuit is adapted to enable and disable the first and second sets of switches in an enabling duration and a disabling duration respectively and alternatively.

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: 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 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 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: A power converter and a control method thereof are provided. The power converter includes a primary side switching circuit, a secondary side switching circuit, a transformer, and a control circuit. The primary side switching circuit includes a first set of switches. The secondary side switching circuit includes a second set of switches. The transformer is coupled between the primary side switching circuit and the secondary side switching circuit. The control circuit is configured to control power transfer between the primary side switching circuit and the secondary side switching circuit by controlling the first and second sets of switches. The control circuit is adapted to enable and disable the first and second sets of switches in an enabling duration and a disabling duration respectively and alternatively.

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: The present disclosure provides a three-phase AC/DC converter aiming for low input current harmonic. The converter includes an input stage for receiving a three-phase AC input voltage, an output stage for at least one load, and one or more switching conversion stages, each stage including a plurality of half bridge modules. The switches in each module operate with a substantially fixed 50% duty cycle and are connected in a specific pattern to couple a DC-link and a neutral node of the input voltage. The AC/DC converter further includes one or more controllers adapted to vary the switching frequency of the switches in the switching conversion stages based on at least one of load voltage, load current, input voltage, and DC-link voltage. The converter can also include one or more decoupling stages, such as, inductive components adapted to decouple the output stage from the switching conversion stages.

Abstract: A microwave generator includes a power supply, an output circuit, a feedback oscillator, a pulse controller, a signal combination circuit and a semiconductor amplifier. The power supply converts input voltage and input current into output voltage and output current. The output circuit generates a microwave signal to an output terminal of the microwave generator and a feedback signal according to the microwave signal. The feedback oscillator generates an oscillation signal according to the feedback signal. According to a reference signal, the pulse controller generates a pulse signal. According to the oscillation signal and pulse signal, the signal combination circuit generates a control signal. The semiconductor amplifier generates and adjusts an amplified signal according to the control signal. The output circuit generates the microwave signal according to the amplified signal. The output current is adjusted according to the amplified signal.

Abstract: A microwave generator includes a power supply, an output circuit, a feedback oscillator, a pulse controller, a signal combination circuit and a semiconductor amplifier. The power supply converts input voltage and input current into output voltage and output current. The output circuit generates a microwave signal to an output terminal of the microwave generator and a feedback signal according to the microwave signal. The feedback oscillator generates an oscillation signal according to the feedback signal. According to a reference signal, the pulse controller generates a pulse signal. According to the oscillation signal and pulse signal, the signal combination circuit generates a control signal. The semiconductor amplifier generates and adjusts an amplified signal according to the control signal. The output circuit generates the microwave signal according to the amplified signal. The output current is adjusted according to the amplified signal.

Abstract: A bidirectional buck-boost converter includes at least one soft-switching cell to reduce switching losses by providing soft-switching of all semiconductor devices. A soft-switching cell comprises an active switch coupled in series with an inductor, a two-winding transformer, and a reset-voltage circuit. The soft-switching cells enable the buck and boost rectifiers to turn off with a controlled turn-off rate of their current to minimize their reverse-recovery losses, the power-controlling buck and boost switch to turn on with zero-voltage switching (ZVS), and the switch of the soft-switching cell to turn off with zero-current switching (ZCS).