Abstract: A voltage source converter based high-voltage direct-current (HVDC) transmission system includes a voltage source converter (VSC)-based power converter channel. The VSC-based power converter channel includes an AC-DC converter and a DC-AC inverter electrically coupled to the AC-DC converter. The AC-DC converter and a DC-AC inverter include at least one gas tube switching device coupled in electrical anti-parallel with a respective gas tube diode. The VSC-based power converter channel includes a commutating circuit communicatively coupled to one or more of the at least one gas tube switching devices. The commutating circuit is configured to “switch on” a respective one of the one or more gas tube switching devices during a first portion of an operational cycle and “switch off” the respective one of the one or more gas tube switching devices during a second portion of the operational cycle.

Abstract: A controller for controlling a power converter is described. The controller includes an input configured to receive at least one grid feedback signal, a filter, and an output. The filter is configured to receive the at least one grid feedback signal and generate an output signal that does not deviate by more than a predefined amount from the at least one grid feedback signal. The output is configured to provide a voltage command signal to the power converter that is based at least partially on the output signal.

Abstract: A device for converting direct voltage from an electrochemical store or a fuel cell to alternating voltage, includes a two-stage design having a single DC/DC converter stage for generating an intermediate circuit voltage from the output voltage of the electrochemical store or the fuel cell, which converter stage converts, in particular raises, the direct voltage in a wide input voltage range directly to an intermediate circuit voltage with which a DC/AC converter stage can be operated to generate the alternating voltage. The single DC/AC converter stage generates the alternating voltage from the intermediate circuit voltage. The invention further relates to a method for actuating a device for converting direct voltage from a store or energy generator into alternating voltage for feeding into a supply network.

Abstract: The present invention concerns a projection system for providing a distributed manifestation within an environment. The projection system includes a data generator for generating a plurality of data sets of associated state data and spatial coordinate data. The projection system also includes a projector in communication with the data generator for receiving the data sets. The projector is provided with a signal generating module for generating a plurality of electromagnetic signals, and a projecting module for projecting each of the electromagnetic signals towards a target location within the environment. The projection system also includes a plurality of receiving units distributed within the environment, each receiving unit having a receiver for receiving one of the electromagnetic signals when the receiving unit is positioned in the corresponding target location, each receiving unit being adapted to perform a change of state in response to the state data.

Abstract: We describe a modular adjustable power factor renewable energy inverter system. The system comprises a plurality of inverter modules having a switched capacitor across its ac power output, a power measurement system coupled to a communication interface, and a power factor controller to control switching of the capacitor. A system controller receives power data from each inverter module, sums the net level of ac power from each inverter, determines a number of said capacitors to switch based on the sum, and sends control data to an appropriate number of the inverter modules to switch the determined number of capacitors into/out of said parallel connection across their respective ac power outputs.

Abstract: In discharging a smoothing capacitor connected to DC sides of first and second switching circuits, a DC-DC converter is first turned on to charge a battery for an auxiliary, thereby discharging the smoothing capacitor. Therefore, an electric charge of the smoothing capacitor can be effectively utilized to the maximum. When the voltage of the smoothing capacitor detected by a voltage detector is reduced to a predetermined value or less, and as a result the DC-DC converter is brought into an inoperable state, electric charge of the smoothing capacitor is consumed by at least one of a motor/generator and an LC filter connected to AC sides of the first and second switching circuits by driving at least one of the first and second switching circuits. Therefore, the smoothing capacitor can be completely discharged without need for a special discharging circuit.

Abstract: Embodiments of the invention provide for circuits for driving LEDs with consistently good illumination and superior efficiency at lower cost and suitable for use with cheaper LEDs or with LEDs having wide component parameter tolerances over wide operating voltages and temperature variations. Circuits disclosed may be, but need not be, embodied on a single semiconductor chip.

Abstract: A ferrite core of the invention is useful for reducing the power loss of Ni--Cu--Zn ferrites, and so for particle accelerators, and power transformers. This core comprises a ferrite magnetic material containing as major components 47 to 50 mol % of iron oxide calculated as Fe.sub.2 O.sub.3, 10 to 25 mol % of nickel oxide calculated as NiO, 2 to 15 mol % of copper oxide calculated as CuO and 15 to 35 mol % of zinc oxide calculated as ZnO, and further containing as subordinate components 0.05 to 1.5 wt % of cobalt oxide calculated as CoO, 0.05 to 0.8 wt % of tungsten oxide calculated as WO.sub.3 and 0.03 to 0.5 wt % of bismuth oxide calculated as Bi.sub.2 O.sub.3, all based on the major components. Consequently, there is achieved a ferrite core having a power loss at 100.degree. C. of up to 210 kW/m.sup.3, and a power loss at 25.degree. C. of up to 140 kW/m.sup.3, as measured at f.multidot.Bm product=25 kTHz (f=1 to 10 MHz).

Abstract: An electric power generating apparatus that is powered primarily by the emission of electrically charged particles from radio-active materials enclosed in an evacuated vessel of glass or the like. An arrangement of reflecting electrodes causes a beam of particles to switch back and forth at a high frequency between two collecting electrodes that are connected to a resonating tuned primary circuit consisting of an inductor with resonating capacitor. The reflecting electrodes are energized in the proper phase relationship to the collecting electrodes to insure sustained oscillation by means of a secondary winding coupled inductively to the primary winding and connected to the reflecting electrodes. Power may be drawn from the circuit at a stepped down voltage from a power take-off winding that is coupled to the primary winding.

Abstract: A circuit arrangement for applying low frequency high voltage waveforms across a load and which includes low and high voltage circuits. The low voltage circuit includes a sinusoidal signal generator for producing a low voltage electrical waveform, and a transmitter circuit having first and second light emitting diode circuits by which first and second light signals are generated which are transmitted to the high voltage circuit by respective fibre optic light guides. The high voltage circuit includes first and second high voltage d.c. supplies and first and second triode valves.