公开(公告)号：US09651603B2

公开(公告)日：2017-05-16

申请号：US15100575

申请日：2014-11-27

Applicant: ABB Schweiz AG

Inventor： Mario Schweizer ,  Roman Grinberg

IPC: G01R31/02 ,  H02M1/088 ,  H02M7/483 ,  G01R31/40

CPC classification number: G01R31/028 ,  G01R31/40 ,  H02M1/088 ,  H02M7/483 ,  H02M2001/0006 ,  H02M2007/4835

Abstract: A method and arrangement for determining a capacitor degradation parameter associated with the degree of degradation of a cell capacitor in a converter cell of a power converter including a plurality of identical converter cells, including redundant converter cells, which converter cell, prior to determining the capacitor degradation parameter, has been bypassed. The method includes a) obtaining a measurement parameter value associated with discharging of the cell capacitor, forming a dc-link, from a measurement start voltage level at a measurement start time to a measurement end voltage level at a measurement end time, and b) determining a value of the capacitor degradation parameter based on the measurement parameter value.