US 12,237,761 B2
Optimizing pulse patterns with Bernoulli polynomials
Tobias Geyer, Ennetbaden (CH); and Hendrik du Toit Mouton, Stellenbosch (ZA)
Assigned to ABB Schweiz AG, Baden (CH)
Appl. No. 17/908,159
Filed by ABB Schweiz AG, Baden (CH)
PCT Filed Jan. 28, 2021, PCT No. PCT/EP2021/052010
§ 371(c)(1), (2) Date Aug. 30, 2022,
PCT Pub. No. WO2021/175518, PCT Pub. Date Sep. 10, 2021.
Claims priority of application No. 20160674 (EP), filed on Mar. 3, 2020.
Prior Publication US 2023/0155481 A1, May 18, 2023
Int. Cl. H02M 1/12 (2006.01); H02M 7/483 (2007.01)
CPC H02M 1/12 (2013.01) [H02M 7/483 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A method for controlling an electrical converter, the electrical converter converting an input voltage (vin) into a multi-level output voltage (vout), the method comprising:
determining an optimized pulse pattern (u(x));
determining switching states from the optimized pulse pattern (u(x)); and
applying the switching states to semiconductor switches of the electrical converter, such that the multi-level output voltage (vout) is generated,
wherein the optimized pulse pattern (u(x)) comprises a plurality of switching transitions (Δu), each switching transition (Δui) implementing, at least in part, a transition between two different levels of the multi-level output voltage (vout), at a switching angle (xi),
wherein the optimized pulse pattern (u(x)) is determined by optimizing a cost function,
wherein the cost function J(x)=ΔuTA(x)Δu is a cost matrix A(x), which is multiplied from both sides with a vector Δu composed of the plurality of switching transitions (Δui), and
wherein each entry of the cost matrix A(x) depends on fourth order Bernoulli polynomials into which the switching angles (xi) are input.