Abb Schweiz Ag

Thomas Besselmann

Mehmet Mercangoez

Stefan Almer

Pieder Jörg

Jan Wiik

Alessandro Zanarini

Drazen Dujic

Martin Bruha

Helfried Peyrl

Sture Van De Moortel

Joerg Pieder

Akos Mester

Andrea Cortinovis

Jörg Pieder

Marc-Alexandre Boechat

A thyristor bridge of an electrical converter is connected to at least one DC link and including at least one phase leg for each output phase and each phase leg being composed of two series-connected thyristor arms. The thyristor arms of a thyristor bridge are cyclically switched by: determining an upper bound for a firing angle of a thyristor arm, wherein the upper bound is determined from voltage and current measurements; and determining a firing angle for the thyristor bridge, which firing angle determines a switching time of the thyristor arm, wherein the firing angle is determined, such that it is less or equal to the upper bound.

Current source converter with dynamical firing angle determination

An electrical converter with at least two output phases includes a rectifier and a thyristor-based inverter interconnected by a DC link with an inductor, wherein the thyristor-based inverter includes a half-bridge with at least two half-bridge arms for each output phase of the electrical converter and each arm being provided by a thyristor. A method for switching the electrical converter includes: cyclically switching the thyristors of the inverter, such that at least one time instant, two thyristors of different half-bridge arms are switched on simultaneously, such that a pulse number, which determines at how many time instants thyristors of the inverter are switched during one stator voltage period, is lower than the number of half-bridge arms of the inverter.

Switching an electrical voltage source converter

A system for controlling an electrical drive including the steps of: receiving an input reference value for a first mechanical variable; estimating a second mechanical variable for a predefined time based on a model based on: a first equation for predicting a future state of the drive system a second equation for predicting at least an actual value of the second mechanical variable; and selecting a first future value from development of the second mechanical variable.

Electrical drive system with model predictive control of a mechanical variable

A load commutated converter interconnects an AC power grid with an AC load and comprises a grid-side converter, a DC link and a load-side converter. A method for controlling the load commutated converter comprises: determining a gridside firing angle for the grid-side converter; determining a load-side firing angle for the load-side converter; determining a grid voltage of the AC power grid; modifying the grid-side firing angle and/or the load-side firing angle based on the grid voltage, such that when an undervoltage condition in the AC power grid occurs, the operation of the load commutated converter is adapted to a change in the grid voltage; and applying the grid-side firing angle to the grid-side converter and the load-side firing angle to the load-side converter.

Controlling a load commutated converter during undervoltage

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Birmenstorf, Switzerland

Thomas Besselmann