Abstract: The invention relates to a method for controlling the voltage and power of several HF inverters (2), connected in parallel at the output, of an electrically isolated inverter assembly as well as for distributing the load to these HF inverters (2) each consisting of at least one DC-DC converter (3), one intermediate circuit (4) and one DC-AC converter (5), with a command variable (Ui?) being formed for each HF inverter (2) so as to preset a nominal value for control of an intermediate-circuit voltage (UZKi) at the intermediate circuit (4) of the HF inverter (2). The load of each HF inverter (2) is determined by a control unit (13) by measuring the current or power required, an internal resistance of the HF inverter (2) is simulated via which internal resistance a virtual voltage drop (UVR) is caused which depends on the load determined and is used for controlling the voltage (UZKi) of the intermediate circuit (4) so as to produce a purposive change in the output voltage of each HF inverter (2).
Type:
Grant
Filed:
July 17, 2007
Date of Patent:
December 28, 2010
Assignee:
Fronius International GmbH
Inventors:
Christian Angerer, Hannes Heigl, Harald Kreuzer
Abstract: A turbomachine for low-temperature applications has a housing, a rotor shaft disposed in the housing, an impeller disposed on one shaft end of the rotor shaft, to which a cold gas is applied, and an electrical machine integrated into the housing. During operation of the turbomachine, a cold zone (K) forms within the housing, in the impeller-side end, and a warm zone (W) forms at the end facing away from the impeller. The housing has at least two compressed gas connectors for a compressed gas, of which one connector is disposed in the cold zone (K), and the other is disposed in the warm zone (W). A control device establishes the flow-through direction for the compressed gas based on temperatures in the cold and warm zones, and controls valve devices on the compressed gas connectors accordingly.
Abstract: A laundry bag is provided that is comprised of an open end and a closed end having an excess of material therebetween. Also provided on the laundry bag are a loop and a drawstring. A sliding device is attached to the drawstring to allow opening and closing the bag. To assure that the proper amount of clothing is placed inside the bag, the laundry bag hangs from a support structure, by the provided loop and drawstring, in a folded manner. The open end of the bag is exposed for inserting clothing therein. Hanging the laundry bag in this folded position forms a front compartment that has an available laundry receiving volume of about 15% to 55%, and a rear compartment so that clothing can expand therein during the drying cycle.
Abstract: The invention relates to an aqueous solution or dispersion with high shellac content. The aqueous shellac solution or dispersion is characterized in that it has a pH value of 2 to 4.2, and contains: 1 to 60% wt. shellac; 0.1 to 3% wt. of at least one water-soluble film former; 0.1 to 1% wt. of at least acid-resistant gel former; and water bringing the total to 100% wt. In accordance with the invention, the solution is produced by the following method: particle-shaped shellac is added to an aqueous solution and homogenized by stirring at 10 to 1500 rev/min., at a temperature of 5 to 20° C. The aqueous solution has a pH value of 2 to 4.2 and contains at least one water-soluble film former and at least one acid-resistant gel former. The shellac solution or dispersion can be used in the paint and varnish industry, the food industry and in cosmetics.