Asea Brown Boveri Ag

Asea Brown Boveri Inc.

Bjorn Odegard

Jochen Rees

Horst Gruning

Herbert Stemmler

Philippe Maibach

Peter Steimer

Sven Klaka

Thomas Keller

Alexander Klett

A semiconductor component including a housing for a semiconductor substrate, an anode, a cathode, an annular gate electrode flange, which laterally protrudes from the housing and concentrically surrounds the housing, and an annular auxiliary cathode flange, which protrudes from the housing and makes contact with the cathode.

Gate controlled thyristor driven with low-inductance

A converter circuit arrangement is specified having a rectifier, an intermediate circuit and an invertor connected thereto. In order to protect the circuit against failures and overvoltage, a protection circuit which comprises, in particular, varistors is connected between the two partial rectifiers of the rectifier.

Converter circuit arrangement with protection circuit

An a.c. machine (7) with, connected in parallel thereto, a capacitor bank (CR, CS, CT), which are fed by a converter (1-4) with a d.c. intermediate circuit, form a resonant system which is excited by the rectangular current of an inverter (4) of the converter. In this case, there is superimposition of the fundamentals and the normal harmonics in the machine voltage and in the machine current of an additional harmonic with the frequency of the resonance point. In the lower speed range of the a.c. machine (7), this excitation is eliminated by an optimum operating sequence of current gaps, which are generated inside a current block by means of a quenching circuit (3). Current gaps are generated at the start and end of each current block for the purpose of damping the 11th and 13th harmonic, and in the middle of the current block for the purpose of damping the 7th harmonic. A turn-on angle basic value signal (.alpha..sub.M) is modified by a turn-on angle differential signal (.DELTA..alpha..sub.M) for the purpose of damping the 5th harmonic, in particular an exciting or available harmonic being controlled to 0 or in the vicinity of 0.

Process and device for eliminating or reducing harmonics and/or

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Turgi, Switzerland

Bjorn Odegard