Abb Schweiz Ag

Abb Ab

Hitachi Energy Switzerland Ag

Abb Power Grids Switzerland Ag

Kalle Ilves

Nan Chen

Jan Svensson

Theodore Soong

Minos Beniakar

Lennart Harnefors

Muhammad Nawaz

NIck Elliott

Federico Bertoldi

Cicero Da Silveira Postiglione

A converter and a method of operating a converter. The converter comprising a DC link capacitor, an upper arm (S) and a lower arm (S) with switching cells in series, an upper switch (S) and a lower switch (S). The upper switch (S) and the lower switch (S) are connected together and the connection point forming an output voltage terminal (a). The converter comprising further an upper valve component and a lower valve component, which are arranged such that the upper valve component allows current from the center point of the DC link capacitor towards the upper arm and the lower valve component allows current from the lower arm towards center point of the DC link capacitor. A current path through the upper valve component or the lower valve component comprises inductance to form a resonance circuit.

Converter

A voltage source converter is configured to generate a pulse train using two voltage levels. The voltage source converter includes a first converter arm coupled between a junction and a first DC terminal having a first voltage level and a second converter arm coupled between the junction and a second DC terminal having a second voltage level. At least one of the first and second converter arms comprises cells. A string of capacitors is coupled between the first and second DC terminals. A control unit is configured to control a group of cells used in a transition between the first and second voltage levels for commutating a current running through a corresponding one of the first and second converter arms involved in the transition.

Voltage source converter generating a pulse train using two voltage levels

A protection arrangement for a multiphase uninterruptible power supply system including a vacuum circuit breaker connected in series with an inductive element, where the inductive element includes, for every phase, two series-connected magnetically coupled windings separated by a tap point. The protection arrangement includes one first group of protective components per phase, each first group including a first protective component having a first end connected to a link between the vacuum circuit breaker and the inductive element and a second end connected to a corresponding tap point, where at least one protective component in each first group is a surge arrester.

Protection of an inductive element

The present disclosure relates to a semiconductor switch leg S for a Power Electronic (PE) converter (). The switch leg comprises a plurality of parallel connected semiconductor devices Sa-d. Each semiconductor device is connected with a positive conductor a-d+ connecting the semiconductor device to a positive terminal of an energy storing device () of the converter, and a negative conductor a-d-connecting the semiconductor device to a negative terminal of the energy storing device () of the converter, the semiconductor device together with the positive conductor and the negative conductor forming a current path across the energy storing device. The semiconductor switch leg comprises a plurality of magnetic coupling devices-, each magnetic coupling device being arranged between the two current paths of respective two neighbouring semiconductor devices of the plurality of semiconductor devices such that the current path of one of the two semiconductor devices and the current path of the other of the two semiconductor devices pass via the magnetic coupling device, and such that each current path passes via two of said plurality of magnetic coupling devices.

Semiconductor switch with magnetic coupling device

A protection arrangement for an uninterruptible power supply system including at least one vacuum circuit breaker connected in series with an inductive element, the protection arrangement including a first bypass branch and a first grounding branch, the first bypass branch being connected in parallel with the inductive element and including two series-connected protective components of a first type and a bypass branch midpoint between them, where the first grounding branch is connected between the bypass branch midpoint and ground and includes a first grounding surge arrester.

Inductive element protection in a power supply system

A multilevel converter cell includes a first section with a first group of series connected switching units in parallel with a first energy storage element, where a junction between a first and second switching units of the first group of series connected switching units forms one cell connection terminal, a second section with a second group of series connected switching units in parallel with a second energy storage element, where a junction between a third and fourth switching units of the second group of series connected switching units forms another cell connection terminal, and an interconnecting section with a third group of series-connected switching units comprising a fifth, sixth and seventh switching unit, with the fifth and sixth switching units connected in parallel with the first energy storage element and the sixth and seventh switching units connected in parallel with the second energy storage element.

Bipolar double voltage cell and multilevel converter with such a cell

A method is provided for controlling a multilevel converter to balance voltages of submodule energy stores. This balancing involves calculating predicted final voltages of energy stores at the end of a time interval to follow and selecting which submodule of a phase arm to insert or bypass during the time interval based on a comparison of the predicted final voltages of the energy stores. The predicted final voltages are updated in accordance with any selection made of which submodule to insert or bypass during the time interval. A control device and a computer program product are also disclosed. Voltage balancing according to a pre-programmed modulation scheme is possible by means of the disclosed method.

Growing community of inventors

Västerås, Sweden

Kalle Ilves