US 12,413,145 B2
Filter capacitance estimation by resonance frequency determination
Vili Väinölä, Espoo (FI); and Jarno Kukkola, Helsinki (FI)
Assigned to ABB Schweiz AG, Baden (CH)
Filed by ABB Schweiz AG, Baden (CH)
Filed on Oct. 3, 2023, as Appl. No. 18/480,066.
Claims priority of application No. 22200134 (EP), filed on Oct. 6, 2022.
Prior Publication US 2024/0128863 A1, Apr. 18, 2024
Int. Cl. H02M 3/158 (2006.01); H02M 1/00 (2006.01); H02M 1/12 (2006.01); H02M 3/00 (2006.01)
CPC H02M 3/015 (2021.05) [H02M 1/0025 (2021.05); H02M 1/126 (2013.01); H02M 3/158 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A method of estimating a quantity dependent on a capacitance (Cf) of an electrical filter connected to an AC side of an electrical converter, the method comprising:
injecting a plurality of frequency components into a voltage reference of the electrical converter, wherein the frequency components have frequencies in a frequency range where at least one of a resonance frequency and an anti-resonance frequency of the electrical filter is expected;
operating the electrical converter with the voltage reference by determining switching commands from the voltage reference and applying the switching commands to the electrical converter;
determining an AC side voltage (uc) and an AC side current (ic) in the AC side of the electrical converter and determining a filter admittance and/or filter impedance from the AC side voltage (uc) and the AC side current (ic) in the AC side of the electrical converter;
determining at least one of a resonance frequency and an anti-resonance frequency of the electrical filter by determining a frequency where a phase angle of the filter admittance and/or filter impedance switches between a negative value and a positive value; and
determining the quantity dependent on the capacitance (Cf) of the electrical filter from the resonance frequency and/or the anti-resonance frequency.