Abstract: A high-voltage DC (HVDC) power system and a method of controlling and protecting the HVDC power system includes a plurality of sending-end (SE) modules coupled in electrical series and a plurality of receiving-end (RE) power converter modules electrically coupled to said plurality of SE modules, the RE modules coupled in a switchyard configuration, the switchyard configuration including a plurality of load branches coupled together in electrical series, each load branch including a branch bypass switch configured to bypass load current around an associated load branch, and a branch protection system.

Abstract: A power converter includes at least one leg including a first string that includes controllable semiconductor switches, a first connecting node, and a second connecting node and that is operatively coupled across a first bus and a second bus. A second string is operatively coupled to the first string via the first connecting node and the second connecting node. The second string includes a plurality of switching modules wherein each of the plurality of switching modules includes a plurality of fully controllable semiconductor switches and at least one energy storage device. The power converter includes a system controller to control activation of the controllable semiconductor switches and switching modules such that a controlled electrical variable is maintained at a first predetermined reference voltage value and the average internal stored energy of the energy storage devices is maintained at a second predetermined reference value.

Abstract: Methods and compositions for synthesizing nucleic acid sequences in an emulsion are provided.

Abstract: A power converter is provided. The power converter includes at least one leg. The at least one leg of the power converter includes a plurality of switching units. The switching units are coupled with each other in a serial fashion. Further, in the power converter, the switching units are selected such that at least two switching units in the power converter have different operating voltages.

Abstract: A method and a high-voltage DC (HVDC) power system are provided. The system includes a plurality of sending-end (SE) modules coupled in electrical series and divided into at least two groups that each operate independently with respect to an electrical ground and a plurality of receiving-end (RE) power converter modules electrically coupled to the plurality of SE modules, the plurality of RE power converter modules including a fast ground-fault detection and control device, the plurality of RE power converter modules including a receiving-end front-end DC-DC converter controller, and an output current damping control.

Abstract: Disclosed is a control and protection device for a low-voltage electrical apparatus, comprising a pedestal and a control and protection module. The control and protection module may be plugged into the pedestal and is replaceable. The pedestal comprises a base and a housing, and is further provided with a moving contact, a static contact, and a current conductor connected to a main circuit current; a control electromagnet operation mechanism for controlling close and open of the moving contact and the static contact according to a control signal, and maintaining a close or open status of the moving contact and the static contact; a manual operation knob providing a control signal for controlling the close and open of the moving contact and the static contact; a control contact connected to the manual operation knob; and a current sensor for detecting a current that flows through the main circuit current conductor and generating a sensing signal.

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 multilevel converter includes at least one phase. Each phase of the multilevel converter includes a direct current (DC) link, a first circuit, a second circuit, and a phase capacitor. The DC link includes a first capacitor, a second capacitor, and a third capacitor situated between the first and second capacitors. The first circuit is electrically coupled to two terminals of the first capacitor. The second circuit is electrically coupled to two terminals of the second capacitor. The phase capacitor is electrically coupled between the first circuit and the second circuit.

Abstract: A multilevel converter includes at least one phase each including several cascaded basic units each including a first switching element, a second switching element, and a separate and electrically isolated DC source (SDCS). The SDCS is electrically coupled between the first switching element and the second switching element in each basic unit. Each of the adjacent pairs of the basic units are electrically crosswise coupled together by electrical coupling of the first switching element of a first basic unit of the two adjacent basic units to the second switching element of a second basic unit of the two adjacent basic units, and electrically coupling the second switching element of the first basic unit to the first switching element of the second basic unit.

Abstract: A power transmission system includes a first unit for carrying out the steps of receiving high voltage direct current (HVDC) power from an HVDC power line, generating an alternating current (AC) component indicative of a status of the first unit, and adding the AC component to the HVDC power line. Further, the power transmission system includes a second unit for carrying out the steps of generating a direct current (DC) voltage to transfer the HVDC power on the HVDC power line, wherein the HVDC power line is coupled between the first unit and the second unit, detecting a presence or an absence of the added AC component in the HVDC power line, and determining the status of the first unit based on the added AC component.

Abstract: Systems and methods for controlling an electrical power supply are provided. One system includes an input configured for receiving voltage measurement signals for the power supply and a controller for one or more electrical phases of the power supply. The controller includes an integrator configured to integrate the received voltage measurement signals and to generate integrated control signals or integrated error signals. The controller is configured to generate an output signal using the integrated control signals or the integrated error signals. The system also includes an output configured to output the output signal to control switching of the power supply.

Abstract: Certain embodiments of the present invention provide a method for controlling Athetis lepigone, which comprises contacting Athetis lepigone with Cry1F protein. Aspects of the present invention can achieve control of Athetis lepigone by enabling plants to produce Cry1F protein in vivo, which can be lethal to Athetis lepigone. In still other instances, the method can control Athetis lepigone throughout the growth period of the plants and provide the plants with a full protection. Additionally, the method, in certain embodiments, can be one or more of stable, complete, simple, convenient, economical, pollution-free or residue-free.

Abstract: Techniques are generally described related to a pedestrian safety system. One example pedestrian safety system may include a sound collector configured to collect an audio signal in an environment of a pedestrian; a processor configured to analyze the collected audio signal to determine whether the audio signal is associated with a vehicle and a distance between the vehicle and the pedestrian; and a notification device configured to notify the pedestrian when the processor determines that the audio signal is associated with the vehicle and the distance is less than a predetermined distance.

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 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 high voltage, high power multi-level drive structure includes a plurality of neutral-point-piloted (NPP) converter cells stacked together. At least one clamping diode is connected to one or many NPP converter cell to provide a neutral-point-pilot-clamped (NPPC) converter structure. Flying capacitors connected to the NPPC converter structure yield a neutral-point-clamped-flying-capacitor converter cell structure.

Abstract: A power transmission system is provided. The power transmission system includes a power source for providing power. The system also includes a power conversion system comprising power converters coupled to receive the power and convert the power to DC power, wherein the power conversion system comprises a plurality of legs each configured for pulse width modulation. The system further includes a controller comprising an analysis module programmed for determining a number of legs for switching for minimizing a cost function based on operating conditions of the power conversion system. The controller also includes a switch control module programmed for using the number of legs determined by the analysis module for generating switching commands for the power conversion system. The system also includes a DC transmission bus coupled to receive the DC power and transmit the DC power.

Abstract: A multilevel converter includes at least one phase. Each phase of the multilevel converter includes a direct current (DC) link, a first circuit, a second circuit, and a phase capacitor. The DC link includes a first capacitor, a second capacitor, and a third capacitor situated between the first and second capacitors. The first circuit is electrically coupled to two terminals of the first capacitor. The second circuit is electrically coupled to two terminals of the second capacitor. The phase capacitor is electrically coupled between the first circuit and the second circuit.

Abstract: A multilevel converter includes at least one phase each including several cascaded basic units each including a first switching element, a second switching element, and a separate and electrically isolated DC source (SDCS). The SDCS is electrically coupled between the first switching element and the second switching element in each basic unit. Each of the adjacent pairs of the basic units are electrically crosswise coupled together by electrical coupling of the first switching element of a first basic unit of the two adjacent basic units to the second switching element of a second basic unit of the two adjacent basic units, and electrically coupling the second switching element of the first basic unit to the first switching element of the second basic unit.

Abstract: A method of reducing radiation dose for a selected organ on a patient in a computed tomography (CT) scan that uses an X-ray source to scan the patient. The method comprises a computer determining a tube start angle for the X-ray source of the CT scan based on a location of the selected organ, a starting location of the X-ray source, a beam width of the CT scan, and a pitch of the CT scan. The starting angle of the X-ray source of the CT scan can then be set based on the determined tube start angle. In some embodiments, the organ location, X-ray starting location, beam width, and pitch are used to determine the number of tube rotations from the X-ray starting location to the organ location. This tube rotation number can be used to determine the tube start angle.