Abstract:
PROBLEM TO BE SOLVED: To provide a system and method for storing electric energy in the form of thermal energy.SOLUTION: A thermoelectric energy storage system comprises a working fluid circuit for circulating a working fluid through a heat exchanger 16 and a thermal storage medium circuit for circulating a thermal storage medium, the thermal storage medium circuit having at least one hot storage tank 24, one intermediate temperature storage tank 22 and one cold storage tank 20 connected together via the heat exchanger 16. A part of the storage medium is redirected to or from the intermediate storage tank from or to the hot or cold storage tank, joining another part which flows directly between the cold and hot storage tank.
Abstract:
PROBLEM TO BE SOLVED: To provide a converter with fast control response, in particular with fast torque response and low harmonic distortion.SOLUTION: A converter 12 for an electrical system 10 is controlled in such a way that switching sequences for the converter 12 that have been determined with respect to a certain first optimization goal are modified in a second step. In the second step, the switching sequence may be optimized further by correcting a flux error that may be the result of certain assumptions on which the first optimization of the switching sequence is based.
Abstract:
PROBLEM TO BE SOLVED: To provide a device with an overvoltage protection function and a test method of a high voltage system to which a surge arrester is connected capable of preventing damage of the surge arrester when testing the high voltage system.SOLUTION: A device with an overvoltage protection function has a varistor 5, and is connected to a high potential of a circuit device 2 via a first line 30 by a first connection part 7, and a second connection part 8 is connected to the ground via a second line 10. The device with the overvoltage protection function has further impedance 17, the impedance 17 is connected between the second connection part 8 and the ground when testing a high voltage system. Corresponding lines 10, 30 are intercepted by a switching device 11, a first line 30 and/or a second line 10 are/is first intercepted, and then the impedance 17 is inserted therein. When test voltage is added to the circuit device 2, voltage of the varistor 5 is lower than the added test voltage, and an overload of the varistor 5 is prevented.