Daimler Chrysler Ag

Abb Research Ltd.

Asea Brown Boveri Ag

Abb Daimler-benz Transportation (technology) Gmbh

Ingo Herbst

Gernot Enzensberger

Stefan Umbricht

Nicholas De Kock

Walter Grossman

Ralf-Dieter Pietsch

Urs Meyer

A method and apparatus for protecting a high-performance power converter. The high-performance power converter comprises a mains power converter, which converts an alternating voltage from a mains power supply into a direct voltage and supplies the direct voltage to an intermediate direct voltage circuit. The intermediate direct voltage circuit is equipped with an intermediate circuit capacitor, and includes a second power converter which converts the direct voltage from the intermediate direct voltage circuit into an alternating voltage, whereby each of the mains power converter and the second power converter is set up as a bridge circuit and each contains a number of IGBTs (Insulated Gate Bipolar Transistors) arranged in pairs in bridge arms. Protection against destruction is achieved in that, when a destructive discharge of the intermediate circuit capacitor via one of the bridge arms, which has become unintentionally continuously conductive, other bridge arms in the power converters are specifically switched through by way of a relief break-through in order to limit the destruction.

Method for protecting a high-performance power converter and a

Converter modules have a busbar system for a plurality of power semiconductor switches or, preferably, IGBT power semiconductor modules (IPMs). The power semiconductor switches are arranged in pairs, facing one another or facing away from one another, close together and parallel. In accordance with exemplary embodiments, alternating current is fed in one or two phases via bridge circuits composed of two or four power semiconductor switches.

Converter modules having a busbar system for power semiconductor switches

A partial-discharge measuring device (3) which detects partial discharges in a gas-insulated, metal-enclosed, high-voltage system. The device includes an annular-gap antenna (6) arranged on the inner surface of the metal enclosure (1), a coaxial measuring cable (7) guided to a measuring instrument, and a tapering adaptor conductor (8) which connects the annular-gap antenna (6) and the coaxial measuring cable (7). The annular gap (9) of the antenna is determined by a plate-shaped electrode (10) which is inserted in an electrically insulated fashion into an opening (5), provided for a flanged attachment (4) in the metal enclosure (1). The adaptor conductor (8) includes an inner conductor, which supports the electrode (10), and is guided onto the shielded conductor (14) of the measuring cable (7), and an outer conductor which is guided onto the shield (15) of the measuring cable (7). The flanged attachment (4) tapers in the shape of a funnel between the opening (5) and the flange (16), and forms with its inner surface a first portion of the outer conductor. The partial-discharge measuring device (3) is of a simple and compact design and can be produced economically. In the UHF region, which is important for an accurate measurement of partial discharges, its transfer function exhibits at frequencies between 300 MHz and 1.8 GHz a portion which is high and flat. The measuring accuracy and sensitivity of the partial-discharge measuring device (3) are therefore particularly high in this frequency region.

Partial-discharge measuring device

This high-voltage installation has a metallic enclosure (1) which is filled with insulating gas and surrounds voltage-carrying active parts. In addition, it has at least one at least partial protective coating (7, 9, 10) either on the internal surface of the enclosure (1) or on the external surface over the active parts, or at least one at least partial protective coating (7, 9, 10) both on the internal surface of the enclosure (1) and on the external surface of the active parts. It is intended to provide a high-voltage installation in which free electrons are also reliably removed from the insulating gaps and in which partial discharges generated by free particles are reduced to noncritical values of intensity. This is achieved in that the at least one protective coating (7, 9, 10) is doped with at least one fullerene which absorbs free electrons. Protective coatings which have a surface of vapor-deposited fullerene are also particularly suitable.

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Greifensee, Switzerland

Ingo Herbst