Abstract: A power converter is presented. The power converter includes at least one leg, the at least one leg includes a first string, where the first string includes a plurality of controllable semiconductor switches, a first connecting node, and a second connecting node, and where the first string is operatively coupled across a first bus and a second bus. Furthermore, the at least one leg includes a second string operatively coupled to the first string via the first connecting node and the second connecting node, where the second string includes a plurality of switching units. A method for power conversion is also presented.

Abstract: A system and method for series connecting electronic power devices are disclosed. In one embodiment, a switching device system includes a first upper arm electrically coupled to a first lower arm and a second upper arm electrically coupled to a second lower arm. Each of the arms include a plurality of low voltage sub-modules connected in series and each plurality of low voltage sub-modules includes an auxiliary switching device, a series switching device, and a capacitor. Each plurality of low voltage sub-modules is configured to be sequentially switched using the auxiliary switching device and the series switching device separately in the upper arms and the respective lower arms to control change in voltage over time (dV/dt) while selectively blocking a desired high voltage. Further, a capacitor voltage balancing (sorting or rotating) algorithm may be used to actively balance voltage across each plurality of low voltage sub-modules.

Abstract: A multi-level DC-DC converter includes an input side to receive a DC power having an input voltage and current, an output side to provide power to a load at a desired output voltage and current, and a plurality of tranformer-isolated DC-DC converters connected between the input and output sides, with the tranformer-isolated DC-DC converters being connected in series on one side and connected in parallel on another side. Each of the tranformer isolated DC-DC converters further includes a power transformer having a primary winding and a secondary winding, and a plurality of switching devices each selectively operable in one of an On state and an Off state. Operating the switching devices in a complementary On state and Off state alternately at a controlled switching frequency provides for engaging the tranformer isolated DC-DC converter and operating the switching devices in a simultaneously On state bypasses the transformer isolated DC-DC converter.

Abstract: A hybrid HVDC converter system includes at least one alternating current (AC) conduit, at least one transformer coupled to said at least one AC conduit, and at least one direct current (DC) conduit. The hybrid HVDC converter system also includes at least one capacitor commutated converter (CCC) configured to convert AC voltages and AC currents to a DC voltage and DC current. The at least one CCC is coupled to the at least one AC conduit through the at least one transformer. The hybrid HVDC converter system further includes at least one self-commutated converter (SCC) configured to convert AC voltages and AC currents to a regulated DC voltage and DC current. The at least one SCC includes at least one AC/DC stage and at least one DC/DC stage coupled to the at least one AC/DC stage.

Abstract: A power converter includes at least one leg with a first string including a plurality of controllable semiconductor switches, a first connecting node, and a second connecting node, wherein the first string is operatively coupled across a first bus and a second bus. The at least one leg also includes a second string operatively coupled to the first string via the first connecting node and the second connecting node, wherein the second string includes a plurality of switching units. The first string includes a first branch and a second branch, wherein the second branch is operatively coupled to the first branch via a third connecting node and the third connecting node is coupled to a ground connection.

Abstract: A multi-phase electronic power transformer includes a set of primary windings, wherein each primary winding is configured to couple with an input voltage. The transformer includes a pair of primary switching devices that includes a first primary switching device coupled to a first end of each primary winding and a second primary switching device coupled to a second end of each primary winding distinct from the first end of each primary winding. The transformer includes a set of secondary windings, wherein each secondary winding is configured to inductively couple with a respective primary winding and to output a voltage. The transformer includes a pair of secondary switching devices that includes a first secondary switching device coupled to a first end of each secondary winding and a second secondary switching device coupled to a second end of each secondary winding distinct from the first end of the each secondary winding.

Abstract: A method for use in reducing an inductance of a circuit including a commutation loop defined at least in part by a source conductor and a return conductor between a first component and a second component is described. The method includes disposing a conductive inductance reducer within the commutation loop. The conductive inductance reducer includes an electrically conductive material and an insulator.

Abstract: A circuit breaker device includes plural bridges conductively coupled parallel to each other between plural terminals that are configured to be conductively coupled with a power source and a load. The bridges include first and second outer bridges each having plural switches and at least an impedance bridge. The switches of the first and second outer bridges are configured to be closed to conduct electric current between the power source and the load and at least one switch in each of the first and second outer bridges are configured to be opened while at least one other switch in each of the first and second outer bridges are configured to remain closed to prevent conduction of the electric current between the power source and the load and to direct the electric current into the impedance bridge.

Abstract: A direct current (DC) transmission and distribution (T&D) system includes a plurality of DC-to-DC converter devices defining a plurality of isolatable portions of the DC T&D system. The DC T&D system also includes a DC T&D control system coupled to the DC-to-DC converter devices. The DC T&D control system includes a plurality of current sensors. At least one of the current sensors is positioned at one of the DC-to-DC converter devices. The current sensor is configured to transmit signals representative of a value of DC electric current transmission through the DC-to-DC converter device. The DC T&D control system also includes a plurality of processors. At least one processor is coupled to the current sensor and the DC-to-DC converter device. The processor is configured to regulate DC current transmission through the DC-to-DC converter device as a function of the value of DC current transmission through the DC-to-DC converter device.

Abstract: A power system for a marine ship includes a plurality of protection zones, wherein at least two protection zones are coupled to each other via at least one bus-tie converter. Each of the protection zones includes a plurality of direct current (DC) buses and a plurality of power converters. The bus-tie converter includes at least two converter legs coupled by at least one inductor. Each converter leg includes a first branch connected with a snubber circuit by an intermediate switching device. The first branch includes two outer switching devices and at least one inner switching device connected between the two outer switching devices. The snubber circuit includes a combination of a diode, a resistor and a capacitor. A controller controls the operation of the plurality of power converters and the at least one bus-tie converter.

Abstract: A system and method for series connecting electronic power devices are disclosed. In one embodiment, a switching device system includes a first upper arm electrically coupled to a first lower arm and a second upper arm electrically coupled to a second lower arm. Each of the arms include a plurality of low voltage sub-modules connected in series and each plurality of low voltage sub-modules includes an auxiliary switching device, a series switching device, and a capacitor. Each plurality of low voltage sub-modules is configured to be sequentially switched using the auxiliary switching device and the series switching device separately in the upper arms and the respective lower arms to control change in voltage over time (dV/dt) while selectively blocking a desired high voltage. Further, a capacitor voltage balancing (sorting or rotating) algorithm may be used to actively balance voltage across each plurality of low voltage sub-modules.

Abstract: A multi-level DC-DC converter includes an input side to receive a DC power having an input voltage and current, an output side to provide power to a load at a desired output voltage and current, and a plurality of tranformer-isolated DC-DC converters connected between the input and output sides, with the tranformer-isolated DC-DC converters being connected in series on one side and connected in parallel on another side. Each of the tranformer isolated DC-DC converters further includes a power transformer having a primary winding and a secondary winding, and a plurality of switching devices each selectively operable in one of an On state and an Off state. Operating the switching devices in a complementary On state and Off state alternately at a controlled switching frequency provides for engaging the tranformer isolated DC-DC converter and operating the switching devices in a simultaneously On state bypasses the transformer isolated DC-DC converter.

Abstract: A power system for a marine ship includes a plurality of protection zones, wherein at least two protection zones are coupled to each other via at least one bus-tie converter. Each of the protection zones includes a plurality of direct current (DC) buses; wherein DC buses which do not have same DC voltage are coupled to each other via at least one DC to DC converter. Furthermore, at least one energy source is coupled to at least one DC bus via a power electronic converter.

Abstract: A hybrid HVDC converter system includes at least one alternating current (AC) conduit, at least one transformer coupled to said at least one AC conduit, and at least one direct current (DC) conduit. The hybrid HVDC converter system also includes at least one capacitor commutated converter (CCC) configured to convert AC voltages and AC currents to a DC voltage and DC current. The at least one CCC is coupled to the at least one AC conduit through the at least one transformer. The hybrid HVDC converter system further includes at least one self-commutated converter (SCC) configured to convert AC voltages and AC currents to a regulated DC voltage and DC current. The at least one SCC includes at least one AC/DC stage and at least one DC/DC stage coupled to the at least one AC/DC stage.

Abstract: An electric power conversion system is coupled to a high voltage direct current (HVDC) transmission system. The electric power conversion system includes a plurality of power conversion modules. At least one of the power conversion modules includes at least one power converter coupled to at least one DC power terminal. The power conversion module also includes at least one isolation device coupled to the at least one power converter. The at least one power converter and the at least one isolation device at least partially define an isolatable portion of the electric power conversion system. The at least one isolation device is configured to remove the isolatable portion from service. The at least one power converter is configured to decrease electric current transmission through the isolatable portion prior to opening the at least one isolation device.

Abstract: A power converter module is provided. The power converter module includes a first converter leg and a second converter leg. The first converter leg includes a first switching unit and a second switching unit coupled in series. The second switching unit is disposed in a reverse orientation with respect to an orientation of the first switching unit. The second converter leg includes a third switching unit and a diode coupled in series. The third switching unit is disposed in a reverse orientation with respect to the orientation of the first switching unit. The power converter also includes a first energy storage device operatively coupled between the first converter leg and the second converter leg. The power converter module further includes a second energy storage device operatively coupled between the first converter leg and the second converter leg.

Abstract: A direct current (DC) transmission and distribution (T&D) system includes a plurality of DC-to-DC converter devices defining a plurality of isolatable portions of the DC T&D system. The DC T&D system also includes a DC T&D control system coupled to the DC-to-DC converter devices. The DC T&D control system includes a plurality of current sensors. At least one of the current sensors is positioned at one of the DC-to-DC converter devices. The current sensor is configured to transmit signals representative of a value of DC electric current transmission through the DC-to-DC converter device. The DC T&D control system also includes a plurality of processors. At least one processor is coupled to the current sensor and the DC-to-DC converter device. The processor is configured to regulate DC current transmission through the DC-to-DC converter device as a function of the value of DC current transmission through the DC-to-DC converter device.

Abstract: A power converter includes at least one leg with a first string including a plurality of controllable semiconductor switches, a first connecting node, and a second connecting node, wherein the first string is operatively coupled across a first bus and a second bus. The at least one leg also includes a second string operatively coupled to the first string via the first connecting node and the second connecting node, wherein the second string includes a plurality of switching units. The first string includes a first branch and a second branch, wherein the second branch is operatively coupled to the first branch via a third connecting node and the third connecting node is coupled to a ground connection.

Abstract: A power converter is presented. The power converter includes at least one leg, the at least one leg includes a first string, where the first string includes a plurality of controllable semiconductor switches, a first connecting node, and a second connecting node, and where the first string is operatively coupled across a first bus and a second bus. Furthermore, the at least one leg includes a second string operatively coupled to the first string via the first connecting node and the second connecting node, where the second string includes a plurality of switching units. A method for power conversion is also presented.

Abstract: An AC-AC Converter for an AC source which in one embodiment has a first rectifier section rectifying the AC source into a first pulsed DC link voltage signal and a high frequency modulating section coupled to the first pulsed DC link voltage signal and producing a high frequency AC voltage signal. A high frequency transformer is coupled to the high frequency AC voltage signal producing a transformed high frequency AC signal. There is a second rectifier section coupled to the transformed high frequency AC signal and producing a second pulsed DC voltage signal and an unfolder section coupled to the second pulsed DC voltage signal and producing an output AC signal.