公开(公告)号：EP3519837A1

公开(公告)日：2019-08-07

申请号：EP17776996.5

申请日：2017-09-25

Applicant: ABB Schweiz AG

Inventor： ROHR, Eduardo ,  AL-HOKAYEM, Peter ,  BAECHLE, Mathias

IPC: G01R27/16 ,  G01R19/25

Abstract: 1. A method for estimating an equivalent impedance ( Z eq ) of a power grid (18) comprises: measuring a plurality of measurement values of a generator voltage ( V gen ) and a generator current ( I gen ) of at least one generator (12) connected to the power grid (18); generating a performance index ( J ) from the plurality of measurement values, the performance index being a function of the measurement values and the grid impedance ( Z eq ); and determining an equivalent impedance ( Z eq ) as the grid impedance, which minimizes the performance index ( J ).

公开(公告)号：EP3320609A1

公开(公告)日：2018-05-16

申请号：EP16736468.6

申请日：2016-07-08

Applicant: ABB Schweiz AG

Inventor： ROHR, Eduardo ,  AL-HOKAYEM, Peter ,  GEYER, Tobias

IPC: H02M1/12 ,  H02M7/217 ,  H02M7/5387 ,  H02M1/00

CPC classification number: H02M1/12 ,  H02M7/217 ,  H02M7/53873 ,  H02M2001/0012 ,  H02M2001/0038

Abstract: A method for operating an electrical converter including: determining an optimized pulse pattern from a fundamental voltage reference for the electrical converter, wherein the optimized pulse pattern is determined from a first lookup table and includes discrete voltage amplitude values changing at predefined switching instants; determining a harmonic content reference from the fundamental voltage reference based on a second lookup table, wherein the harmonic content reference is a harmonic current reference determined from the frequency spectrum of a current of the electrical converter or the harmonic content reference is a filtered voltage reference determined by applying a first order frequency filter to a voltage, which current or voltage is generated, when the optimized pulse pattern is applied to the electrical converter; determining a harmonic content error from the harmonic content reference by subtracting an estimated output voltage and/or estimated output current of the electrical converter from the harmonic content reference; modifying the optimized pulse pattern by timeshifting switching instants such that the fundamental voltage reference is tracked and the harmonic content error is corrected by the timeshifted switching instants; applying the modified optimized pulse pattern to semiconductor switches of the electrical converter.