A soft switching resonant converter is disclosed. The converter includes a power switch operable to connect and disconnect a DC link rail node and an output node. A resonant capacitor is coupled with the power switch. An auxiliary leg is coupled with a DC link midpoint node and the output node. An active damper is coupled in series with the resonant capacitor and the output node and is controllable to provide a first resistance of the active damper in a first state and a second resistance of the active damper in a second state, the first resistance having a lower magnitude than the second resistance. A driver controls the damper switch to provide a first resistance during the soft switching operation of the power switch and a second resistance after the soft switching operation of the power switch.

Disclosed is a power converter including a generator configured to generate a sequence of output voltage waveforms, a resonant tank connected to the generator comprising at least one capacitor and at least one inductor, a transformer including a primary side connected in series with said series inductor and, the primary side being configurable to use at least one primary winding tap and a secondary side for connecting to a rectifying circuit for providing a rectified DC voltage to an output load circuit, a first switch and a second switch on the primary side connected to the primary winding, wherein the at least one primary winding is selected by the first switch or the second switch to select a different reflected output voltage by closing the first switch or the second switch.

Unique systems, methods, techniques and apparatuses of zero-voltage transition pulse width modulation resonant converters are disclosed. One exemplary embodiment is a zero-voltage transition PWM resonant converter comprising a DC bus, a first switching device, a second switching device, a resonant tank circuit, an auxiliary circuit having a flying capacitor and a plurality of auxiliary switching devices, and a controller. The controller is structured to control the first switching device, the second switching device, and the plurality of auxiliary switching devices to provide resonant operation of the tank circuit effective to provide a substantially zero voltage condition across the first switching device when turning the first switching device on or off and to provide a substantially zero voltage condition across the second switching device when turning the second switching device on or off.

According to at least one aspect of the disclosure, an inverter is provided comprising an input configured to receive input DC power from a DC source, an output configured to provide output AC power to a load, a plurality of DC rails coupled to the input and configured to receive the input DC power from the DC source, a plurality of switches coupled between the plurality of DC rails and configured to convert the input DC power into the output AC power, each switch of the plurality of switches having a parasitic capacitance, and at least one ZVS network coupled across at least two switches of the plurality of switches, the ZVS network including at least two inductors configured to resonate with the parasitic capacitance of at least one switch of the plurality of switches to provide soft switching of at least one switch of the plurality of switches.

A direct current (DC) to DC power converter includes a first converter for converting a first DC bus voltage into a first high frequency AC voltage and a second converter for converting a second high frequency alternating current (AC) voltage into a second DC bus voltage. The DC to DC converter also includes a resonant circuit for coupling the first bus converter and the second bus converter and a controller for providing switching signals to the first converter and the second converter to operate the power converter in a soft switching mode. The resonant circuit includes a high frequency transformer coupled between the first converter and the second converter and an auxiliary converter coupled in series with a first resonant inductor and the high frequency transformer. The resonant circuit further includes second inductor coupled across a first winding of the high frequency transformer. An auxiliary voltage generated by auxiliary converter is added in series with an output voltage of the first converter.

The invention relates to a method for controlling an inverter and to an inverter a DC/DC stage, which comprises at least one main switch (S2) and a discharge circuit, and with a DC/AC stage. The discharge circuit is formed by a series connection of a bidirectional switching element, which comprises two switches (SA1, SA2), and an inductivity. A device is provided for controlling the switches (SA1, SA2) and is designed such that one switch (SA1, SA2) is activated in an alternating manner and the switch-on time of the switch is determined by the controlling device prior to a switch-off time of the main switch (S2).

A voltage source converter includes a number of valves, the valves including switching elements with anti-parallel diodes provided in a bridge for switching between two states. The bridge is provided in at least one phase leg that stretches between two direct current poles and has at least one midpoint, which is connected to an alternating current terminal. The switching element of at least one valve is a thyristor. The converter further includes a commutation cell associated with the valve, where the commutation cell is controllable to reverse-bias the valve if it is to stop conducting current.

A soft switching resonant converter is disclosed. The converter includes a power switch operable to connect and disconnect a DC link rail node and an output node. A resonant capacitor is coupled with the power switch. An auxiliary leg is coupled with a DC link midpoint node and the output node. An active damper is coupled in series with the resonant capacitor and the output node and is controllable to provide a first resistance of the active damper in a first state and a second resistance of the active damper in a second state, the first resistance having a lower magnitude than the second resistance. A driver controls the damper switch to provide a first resistance during the soft switching operation of the power switch and a second resistance after the soft switching operation of the power switch.

An auxiliary resonant soft-edge pole inverter circuit is provided. The power inverter circuitry may include a first pair of capacitors in parallel with a corresponding pair of main power switching modules, each power switching module comprising a switch and a diode in parallel and sharing a common central node with the first pair of capacitors. The power inverter circuit may further include a first pair of auxiliary switches connected in series with a first pair of inductors, respectively, to generate resonant current from a DC power source, the first pair of inductors also sharing the common central node. The power inverter circuitry may further include a second pair of auxiliary switches connected in series with a second pair of capacitors, respectively, the second pair of auxiliary switches also sharing the common central node, the circuit producing an alternating current output at the common central node.

According to at least one aspect of the disclosure, an inverter is provided comprising an input configured to receive input DC power from a DC source, an output configured to provide output AC power to a load, a plurality of DC rails coupled to the input and configured to receive the input DC power from the DC source, a plurality of switches coupled between the plurality of DC rails and configured to convert the input DC power into the output AC power, each switch of the plurality of switches having a parasitic capacitance, and at least one ZVS network coupled across at least two switches of the plurality of switches, the ZVS network including at least two inductors configured to resonate with the parasitic capacitance of at least one switch of the plurality of switches to provide soft switching of at least one switch of the plurality of switches.