Abstract: A novel phase-shift based modulation strategy is disclosed that enables a DC-DC converter to operate with zero voltage-switching (ZVS) across wide voltage and power range. The converter operates at a fixed fundamental frequency, with the output current controlled based on an amount of phase shift of the fundamental component at the output of an inverter portion of the converter. To achieve soft switching a rectifier portion of the converter is controlled to phase shift the fundamental component of the rectifier voltage observed at a rectifier reference terminal. More specifically, by requiring a phase shift of the voltage at the rectifier terminal relative to the output voltage of the inverter, the inverter current is such that ZVS is achieved. A converter and method are provided to implement DC-DC conversion with soft switching.

Abstract: A DC/DC converter may be formed out of the combination of a first converter that is optimized to transfer energy from a voltage source to a load, and a second converter that receives a control signal derived from the load voltage to regulate the load voltage. The DC/DC converter may be configured as a sigma converter, a delta converter, or a sigma-delta converter. The mode of operation being selected according to the source voltage or the load voltage, either of which may vary over a wide range.

Abstract: A power supply system includes a set of power supply units, each power supply unit arranged electrically in series and defining a common power supply, each power supply unit having a power module and a selective bypass for selectively bypassing the respective power module. The power supply system can meet a power demand.

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: The present disclosure provides a high voltage device built from modular low voltage cells. Each low voltage cell includes a plurality of low voltage semiconductor devices and one or more low voltage passive components. Each cell can be a current-bidirectional two-quadrant switch or a four-quadrant switch. All the cells may be identical and controlled with a delay time in between. Therefore, the total on and off time of the high voltage device can be controlled to reduce the output equivalent dv/dt. The cell's voltage balancing can be achieved through a control algorithm disclosed herein.

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 multilevel converter system is provided. The system includes a converter and a converter controller interfaced with the converter. The converter controller includes a voltage loop, a current loop, and a voltage compensation loop. The voltage loop is configured to receive first and second voltages from the first and second segments of the converter and a reference voltage. The current loop is configured to receive a current output of the converter, a reference current, and a balancing reference current. The voltage compensation loop is configured to receive the first and second voltages and a sign signal. The converter controller is configured to generate first and second pulse-width modulation (PWM) signals using output signals from the current loop and the output compensation signals from the voltage compensation loop. The PWM signals are configured to control the switches of the converter and to balance the first voltage with the second voltage.

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 modular power converter system includes a plurality of active power link modules (APLMs) coupled to each other, each APLM having a plurality of switching devices including first and second switching devices coupled to each other, and at least one first-type energy storage device (ESD) coupled in parallel with both of the first and second switching devices, the first-type ESD configured to induce a first direct current (DC) voltage. The system also includes a plurality of relays coupled to the first-type ESD, and a charge controller coupled to at least one APLM of the plurality of APLMs and coupled to at least one of an electrical power source and a discharge circuit. The charge controller is configured to alternately charge and discharge the first-type ESD in response to a plurality of switching states including switching states of the plurality of switching devices and the plurality of relays.

Abstract: A system including a control system is provided. The control system includes a main drive that receives power from a power source and outputs a variable frequency and a variable amplitude AC voltage. The control system also includes a controller to interface with the main drive and an electric machine. The controller receives one or more electrical signals associated with an operating condition of the electric machine from one or more sensors disposed between the electric machine and the main drive. The controller determines correction information based on the received electrical signals and based on a desired operating condition of the electric machine. The controller transmits the correction information to the main drive. The correction information corresponds to a rotor position of the electric machine or operating commands configured to implement the desired operating condition of the electric machine.

Abstract: A DC/DC converter may be formed out of the combination of a first converter that is optimized to transfer energy from a voltage source to a load, and a second converter that receives a control signal derived from the load voltage to regulate the load voltage. The DC/DC converter may be configured as a sigma converter, a delta converter, or a sigma-delta converter. The mode of operation being selected according to the source voltage or the load voltage, either of which may vary over a wide range.

Abstract: A power supply system includes a set of power supply units, each power supply unit arranged electrically in series and defining a common power supply, each power supply unit having a power module and a selective bypass for selectively bypassing the respective power module. The power supply system can meet a power demand.

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: A system for monitoring a junction temperature of a semiconductor device includes a sensing resistor electrically coupled to a source terminal of the semiconductor device in a gate loop of the semiconductor device. The system includes a detection circuit electrically coupled to the gate loop of the semiconductor device and configured to measure a voltage difference across the sensing resistor. The system also includes an electronic control unit electrically coupled to the gate loop and the detection circuit. The electronic control unit is configured to determine a first gate current peak during a switching process of the semiconductor device, wherein the first gate current peak is determined based on the voltage detected by the detection circuit. The electronic control unit is configured to determine the junction temperature based on the first gate current peak.

Abstract: An energy storage system includes an energy storage device that has a plurality of cells. The energy storage system further includes a string power converter connected in series between the energy storage device and a direct current (DC) bus, and a plurality of cell power converters each connected across a respective one of the energy storage device cells.

Abstract: Systems and methods to improve operation of a modular multilevel converter. Some embodiments include a first upper arm with a first active power link module, which facilitates producing a first portion of a first alternating current electrical power at a base frequency and injecting a first even-order current harmonic of the base frequency in the first upper arm, and a first lower arm with a second active power link module, which facilitates producing a second portion of the first alternating current, in which the first portion of the first alternating current and the second portion of the alternating current are combined to facilitate outputting the first alternating current electrical power at a first alternating current terminal, and injecting the first even-order current harmonic in the first lower arm, in which magnitude of the first even-order current harmonic is zero at the first alternating current terminal.

Abstract: Methods of depositing fluorine-free tungsten by sequential CVD pulses, such as by alternately pulsing a fluorine-free tungsten precursor and hydrogen in cycles of temporally separated pulses, are provided. Some methods involve depositing fluorine-free tungsten by sequential CVD without depositing a tungsten nucleation layer. Methods also include depositing tungsten directly on a substrate surface using alternating pulses of a chlorine-containing tungsten precursor and hydrogen without treating the substrate surface. Methods also include depositing a tungsten layer using a reducing agent and fluorine-free tungsten-containing precursor and depositing bulk tungsten in sequential CVD cycles of alternating pulses of hydrogen and a tungsten-containing precursor.

Abstract: A system for monitoring a junction temperature of a semiconductor device includes a sensing resistor electrically coupled to a source terminal of the semiconductor device in a gate loop of the semiconductor device. The system includes a detection circuit electrically coupled to the gate loop of the semiconductor device and configured to measure a voltage difference across the sensing resistor. The system also includes an electronic control unit electrically coupled to the gate loop and the detection circuit. The electronic control unit is configured to determine a first gate current peak during a switching process of the semiconductor device, wherein the first gate current peak is determined based on the voltage detected by the detection circuit. The electronic control unit is configured to determine the junction temperature based on the first gate current peak.

Abstract: A modular power conversion device includes at least one first-type energy storage device (ESD) configured to induce a first direct current (DC) voltage, and at least one active power link module (APLM) string coupled to the at least one first-type ESD. The at least one APLM string includes a plurality of APLMs coupled to each other. Each APLM of the plurality of APLMs has a plurality of switching devices including a first switching device and a second switching device coupled to each other in electrical series. Each APLM of the plurality of APLMs also has at least one second-type ESD coupled in electrical parallel with both of the first switching device and the second switching device. The at least one second-type ESD is configured to induce a second DC voltage.