Abb Schweiz Ag

Daimler Chrysler Ag

Abb Research Ltd.

Asea Brown Boveri Ag

Tudor Baiatu

Reinhard Fried

Peter Etter

Hans-Jurg Wiesmann

Felix Greuter

Ralf Strumpler

Harm De Roo

Harm deRoo

A busbar system includes a busbar with at least two parallel arranged phase conductors running between a first end and a second end of the busbar and at least two feeders connected onto the busbar, each feeder including contacts for at least some of the phase conductors of the busbar; a first supply line and a second supply line interconnecting the first feeder and the second feeder with a common power supply; wherein a first feeder of the at least two feeders is connected onto the first end of the busbar and a second feeder of the at least two feeders is connected onto the second end of the busbar; wherein each of the first supply line and the second supply line has a higher impedance than the busbar.

Multiple fed busbar system

Charging station

The present invention specifies an arc quenching device having improved current limitation and reduced heat losses, in the case of which a moving contact piece () is not subject to increased erosion and wear. For this purpose, a quenching path according to the invention is provided which takes over an arc from said contact piece () and comprises arc guide rails (), a quenching chamber () and a current-limiting element (). Based on circuit breakers with double interruption, the current-limiting element () is preferably provided between arc guide rails () of a second contact point and provided with a blowing section () for additional magnetic blowing of the arc of the first contact point.

Arc quenching device for circuit breakers

Current limiters, preferably PTC resistors, are used for limiting short-circuit current when connected in series to capacitors and converter valves. Protective devices operating with these PTC resistors are able to work reversibly and respond without arcing. They have a low inductance and can be used in space-saving designs. Protective circuits with such PTC resistors have a low loss, are shake-proof, and can be integrated into an existing cooling circuit. They respond autonomously and enable a flexible application. The PTC resistors preferably are constructed in a meander shape of porous metal foam or a metal braid or fabric and have electrical contact bridges between their resistor tracks. At least 2 resistor tracks that are electrically connected in parallel are arranged at a small distance on top of each other in such a way that partial currents (I1, I2) flow in opposite directions through resistor branches in superposed track areas formed in this manner. The resistor tracks can also be arranged in grooves of a cooling body or may have a circular shape. A compensation resistor for compensating uncompensated marginal areas of these resistor tracks can be provided in serial connection to meander-shaped, parallel connected resistor tracks.

Overcurrent limiter having inductive compensation

PTC thermistors are used in reversible short circuit current limiters, in particular in series connection with electrical valves and/or capacitors. An electrically insulated, thermally conductive insulation or ceramic layer (20) is in contact electrically and with good thermal conduction via a first main surface with a metallic cooling element (25). A second main surface of the ceramic layer (20), opposite the first main surface, is covered with an electrically insulating thermal-conduction layer (21) having a thickness in the range from 10 .mu.m-100 .mu.m. Meandering tracks (16) of the resistive body of the PTC thermistor (5) are pressed between this thermal conduction layer (21) and an electrically insulating, preferably thermally conductive, flexible high-temperature stable polymer film (22). In order to provide pressure, a pressure compensation cushion (23) on which a force (F) orthogonal to the second main surface of the ceramic layer (20) acts, may be provided. The pressure compensation cushion (23) is filled with a dielectric or electrically conductive fluid (24) having a boiling temperature above preferably 150.degree. C. The resistive track (16) may also be embedded in a filled polymer matrix, it being possible for geometrically congruent resistive tracks to be opposite on a ceramic layer.

PTC thermistor and a current limiter device having at least one PTC

A reversible short circuit current limiter which has at least one PTC thermistor connected in parallel with a shunt impedance branch, and is connected in series with at least one capacitor or a capacitor bank of the DC intermediate circuit. The short circuit current limiter may be arranged in the DC intermediate circuit or in the current convertor. A diode may be connected in the reverse-bias direction of a short circuit path in parallel with the PTC thermistor. The shunt impedance branch has a varistor connected in series with an ohmic resistor or a PTC thermistor and, if appropriate, an inductor. Structures of metal-based nonblocking PTC thermistors are specified.

Current limiter device

The electrical resistance element (10) includes a resistance body (3), which is arranged between two plane-parallel, pressurized electrodes (1, 2), has PTC behavior and comprises a polymer matrix and two filler components of electrically conducting particles embedded into the polymer matrix (4). When a short-circuit current occurs, the resistivity of the resistance body (3) changes abruptly above a temperature limit value in a surface layer resting on the electrodes and containing at least a first of the two filler components. A second of the two filler components is selected such that a composite material containing at least the polymer matrix and the second filler component has PTC behavior, with an abruptly changing behavior greater by at least one order of magnitude in comparison with the surface layer. At the same time, this composite material has a resistivity which is lower by at least one order of magnitude than a composite material formed by the polymer matrix and the first filler component. The resistance element has a high nominal current carrying capacity and can limit large short-circuit currents permanently.

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Brugg, Switzerland

Tudor Baiatu