Abstract: A power electronic building block is provided, including capacitors, switch modules, a busbar arrangement, and at least one AC busbar. Connection points of the at least one AC busbar are arranged symmetrically along a first direction with respect to a plane perpendicularly intersecting the first direction, and the at least one AC busbar includes a hole elongated along the first direction and configured to balance one or more loop inductances between at least one AC external terminal point and the connection points. A modular multilevel converter (MMC) is also provided, including a plurality of converter arms each including at least one sub module formed by the PEBB.

Abstract: A cell (12) comprises a first cell connection terminal (CC1), a second cell connection terminal (CC2), a first series connection of two switches (T1, T2), an energy storage branch (ESB) comprising a capacitor (CC) and a first power link interconnecting the first series connection of two switches (T1, T2) with the energy storage branch (ESB), where the first power link has an inductance (LBB1) that changes based on the current through it. There is also a converter comprising such a cell.

Abstract: A method for estimating at least one leakage inductance of a 3n-phase electrical machine includes performing a first machine investigation scheme and a second machine investigation scheme, the first scheme including ordering a machine drive stage to control one of the 3-phase windings, obtaining a first set of measured currents from the 3-phase winding and processing the first set of measured currents to obtain primary characteristics of an electrical quantity of the electrical machine, the second scheme including ordering the machine drive stage to control all the 3-phase windings using a VSD control model, the controlling involving only controlling a first fundamental subspace of the VSD control model, obtaining a second set of measured currents from all 3-phase windings and processing the second set of measured currents to obtain a leakage inductance estimate and secondary characteristics of the electrical quantity, for which leakage inductance estimate the primary and secondary characteristics match.

Abstract: An AC-to-AC modular multilevel converter (MMC) is configured to be connected between a three-phase AC system and a single-phase AC system. The MMC includes a number of converter arms connected in a ring to allow a circulating current to be circulated in the ring through each of the converter arms. Each converter arm includes series-connected converter cells. Phase terminals are arranged in the ring between the converter arms such that each of the converter arms is separated from neighboring converter arms by at least one of the phase terminals. The phase terminals include respective terminals for each of a first phase, a second phase and a third phase of the three-phase AC system and respective terminals for each of a positive conductor and a negative conductor of the single-phase AC system.

Abstract: An AC-to-AC modular multilevel converter (MMC) is configured to be connected between a three-phase AC system and a single-phase AC system. The MMC includes a number of converter arms connected in a ring to allow a circulating current to be circulated in the ring through each of the converter arms. Each converter arm includes series-connected converter cells. Phase terminals are arranged in the ring between the converter arms such that each of the converter arms is separated from neighboring converter arms by at least one of the phase terminals. The phase terminals include respective terminals for each of a first phase, a second phase and a third phase of the three-phase AC system and respective terminals for each of a positive conductor and a negative conductor of the single-phase AC system.

Abstract: A method of controlling a multi-phase electrical machine by means of a power converter, wherein the method includes: a) controlling the electrical machine by utilizing vector space decomposition, VSD, wherein the controlling involves releasing control of the current of a harmonic while maintaining control of the current of the fundamental, b) measuring phase currents of the electrical machine while the control of the current of the harmonic is released, c) transforming the current measurements using VSD to obtain a current signature of the harmonic, and d) determining whether a fault is present in the electrical machine or the power converter based on a comparison of the current signature with a reference current signature of the harmonic.

Abstract: A method of controlling a multi-phase electrical machine by means of a power converter, wherein the method includes: a) controlling the electrical machine by utilizing vector space decomposition, VSD, wherein the controlling involves releasing control of the current of a harmonic while maintaining control of the current of the fundamental, b) measuring phase currents of the electrical machine while the control of the current of the harmonic is released, c) transforming the current measurements using VSD to obtain a current signature of the harmonic, and d) determining whether a fault is present in the electrical machine or the power converter based on a comparison of the current signature with a reference current signature of the harmonic.

Abstract: It is presented a power converter for converting power between a first high voltage direct current, DC, connection, a second high voltage DC connection and a high voltage alternating current, AC, connection. The power converter comprises: a first phase arrangement comprising a first converter arm, a second converter arm, a third converter arm, a fourth converter arm, a fifth converter arm and a sixth converter arm. The first, second third and fourth converter arms are serially connected in the mentioned order between two terminals of the first high voltage DC connection. The high voltage AC connection is connected between the second converter arm and the third converter arm.

Abstract: It is presented a power converter for converting power between a first high voltage direct current, DC, connection, a second high voltage DC connection and a high voltage alternating current, AC, connection. The power converter comprises: a first phase arrangement comprising a first converter arm, a second converter arm, a third converter arm, a fourth converter arm, a fifth converter arm and a sixth converter arm. The first, second third and fourth converter arms are serially connected in the mentioned order between two terminals of the first high voltage DC connection. The high voltage AC connection is connected between the second converter arm and the third converter arm.