Abb Schweiz Ag

Abb Technology Ltd

Liwei Wang

Alireza Nami

Frans Dijkhuizen

Jiaqi Liang

Ola Jeppsson

Åke Öberg

Filippo Chimento

Jian Qin

A multilevel converter converting between AC and DC includes a phase leg having a first and a second phase arm, the first phase arm being connected between a first pole having a first potential and a first AC terminal and the second phase arm being connected between the first AC terminal and a second potential, where the phase arms include half-bridge and full-bridge cells, where each cell includes at least one energy storage element for providing the voltage contribution and cell switching units with cell switches and anti-parallel diodes for controlling the voltage contribution, where the full-bridge cells include a bypass switch controllable to bypass the corresponding energy storage element, and when a phase-to-ground fault occurs the cell switches are blocked and the bypass switches activated with a delay in relation to the blocking.

Multilevel converter with reduced AC fault handling rating

A multilevel converter converting between AC and DC includes a phase arm with a number of cells between a DC pole and an AC terminal, the cells include at least one hybrid full bridge cell including a first cell connection terminal for coupling to the DC pole, a second cell connection terminal for coupling to the AC terminal, an energy storage element having a positive and a negative end, a first group of series connected semiconducting units in parallel with the energy storage element, where a junction between these forms one cell connection terminal, and a second group of series connected semiconducting units in parallel with the energy storage element and including a third semiconducting unit and a fourth semiconducting unit consisting of a number of unidirectional conducting elements including at least one unidirectional conducting element, where a junction between these forms a further cell connection terminal.

Multilevel converter with hybrid full-bridge cells

It is presented a converter cell () arranged to be used in a high voltage multilevel converter. The converter cell comprises: an energy storage element () and a plurality of switching elements (S, . . . , S). The plurality of switching elements comprises at least one thyristor (S; S) and a plurality of transistors (S, S, S; S, S, S). Each one of the at least one thyristor (S; S) is provided in a position for a switching element in the converter cell where, during normal operation of the converter cell, the at least one thyristor is in a continuous conducting state. This reduces the power losses of the converter cell. A corresponding multilevel converter and a method are also presented.

Converter cell with reduced power losses, high voltage multilevel converter and associated method

A mechanical switch in the form of a bypass switch assembly is arranged between two electrical conductors (busbars) and stays open during normal operation. When a cell fault happens, the fault and bypass information is transmitted to an actuator (acting as a trigger circuit) which activates inter alia a gas generator producing huge volume of gas in a very short time. The gas pressure pushes a movable member to bridge the two electrical conductors with ultrafast speed.

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Kelowna, Canada

Liwei Wang