Ecole Polytechnique Federale De Lausanne

Alstom Technology Limited

European Organization for Nuclear Research

Ecole Polytechnique Féderale De Lausanne (epfl)

Alfred Rufer

Sylvain Lemofouet

Reinhard Joho

Oliver Drubel

Martin Veenstra

Daniel Favrat

Jean-Jacques Simond

Jean-Paul Burnet

Philippe Barrade

Claude Fahrni

Frederick Bordry

A device for supplying power to a load, requiring both a pre-determined supply of electrical power and high power for short durations of the operating cycle of the load, where the operating cycle is repeated. The power supply device includes a connection to an electrical grid, an AC voltage transformation circuit, a voltage rectification means and a plurality of DC/DC converters mounted in series to terminals of the load. Each of the DC/DC converters has a storage capacitor mounted in parallel to it and at least one of the DC/DC converters is supplied directly by the voltage rectification means. At least another one of the DC/DC converters is not supplied directly by the voltage rectification means. The power supply device may compensate for losses in the power supply device and load, and may substantially continually and uniformly balance voltages at terminals of the storage capacitors.

Device for feeding a charge including integrated energy storage

Multistage hydraulic systems and methods for converting the potential energy of a pressurized gas, particularly air, into mechanical work when operating in motor, and for producing compressed gas from the mechanical work of the rotating shaft when rotating when operating in compressor mode, by performing a successive expansion/compression of the said gas. Each of the systems comprises: a multistage Compression-Expansion Unit made of several hydraulic Compression-Expansion Modules having different capacity and integrating a gas/liquid separating heat exchanger, designed to convert pressure power into a hydraulic power and vice-versa, by performing an essentially isothermal compression/expansion of the gas; a single stage or multistage, direct or indirect, external forced-air Heat Exchanger for maintaining the active liquid at ambient temperature; and a multi-circuit, multi-displacement Hydraulic Motor/Pump for converting hydraulic power into mechanical power and vice-versa.

Multistage hydraulic gas compression/expansion systems and methods

Different types of energy storage systems are described, in particular hydro-pneumatic storage systems. In one, energy is stored by compressing gas in a chamber () with a liquid piston and released by gas expansion. A spray head or grid at the top of the chamber () supplies liquid as a shower through the gas being compressed or expanding in the cylinder () to maintain an isothermal condition. In another, energy is stored from an array of solar cells connected to an array of supercapacitors forming an auxiliary storage, and a main energy storage device such as a hydro-pneumatic storage system, for supply to an AC or DC network. The efficiency is improved by connecting the solar cells via the array of supercapacitors to the AC or DC network. An immersed hydro-pneumatic storage device for off-shore/on-shore power generation systems comprises a cylinder that is immersed in a liquid mass, wherein energy is stored by compressing gas with a liquid piston and energy is released by gas expansion. The mass of liquid maintains an isothermal condition in the cylinder during compression and expansion.

Energy storage systems

A generator having electronic circuit breakers as circuit breakers, whereby circuits comprising thyristors, IGBT elements and/or GTO thyristors are used, and whereby the circuit breakers are integrated into the generator, preferably in that the circuit breakers are distributed on parallel winding branches of the stator. Such power electronics can also be used for switching generators having a power above 50 MV with very short switching times of a few milliseconds.

Generator with integrated powerswitch

The present invention relates to a method and to a device for adapting the alternating current generated by a generator () and the alternating voltage generated by a generator () to a grid (), whereby the generator () has at least one excitation coil (). The power fed into the grid () can be flexibly adapted while entailing low switching losses in that a static frequency converter () is employed for the adaptation between the generator () and the grid (), and in that, in order to control the power fed into the grid (), means () are provided with which, on the one hand, the strength of the excitation field generated by the at least one excitation coil () is regulated and, on the other hand, the phase angle between the frequency converter voltage and the generator or grid voltage is appropriately controlled.

Frequency converter for high-speed generators

Growing community of inventors

Villars-sous-Yens, Switzerland

Alfred Rufer