US 12,149,173 B2
Multiphase DC-DC converter and method for controlling a multiphase DC-DC converter
Peter Oehry, Wittenbach (CH); Adrian Immler, Buchs (CH); and Martin Erler, Dornbirn (AT)
Assigned to BRUSA HyPower AG, Sennwald (CH)
Appl. No. 17/761,230
Filed by BRUSA HyPower AG, Sennwald (CH)
PCT Filed Sep. 16, 2020, PCT No. PCT/EP2020/075909
§ 371(c)(1), (2) Date Mar. 17, 2022,
PCT Pub. No. WO2021/053038, PCT Pub. Date Mar. 25, 2021.
Claims priority of application No. 19198468 (EP), filed on Sep. 19, 2019.
Prior Publication US 2022/0368233 A1, Nov. 17, 2022
Int. Cl. H02M 3/158 (2006.01); H02M 1/00 (2006.01); H02M 1/14 (2006.01); H02M 1/44 (2007.01)
CPC H02M 3/1586 (2021.05) [H02M 1/0009 (2021.05); H02M 1/0058 (2021.05); H02M 1/14 (2013.01); H02M 1/44 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A control method for controlling a multiphase DC-DC converter the multiphase DC-DC converter being arranged for exchanging electrical power between an input side, comprising a first input terminal and a second input terminal, and an output side, comprising a first output terminal and a second output terminal, the multiphase DC-DC converter comprising two or more phase circuits,
each phase circuit comprising a switch and an inductor, the switch being arranged to control an inductor current IL through the inductor,
the phase circuit being arranged to generate a phase current contributing to a total current to be delivered to an output side of the multiphase DC-DC converter, the method comprising:
switching two or more of the phase circuits in Boundary Conduction Mode (BCM) to generate interleaved phase current pulses, with a period length T and a turn-on time period ton of the switch;
in at least one of the two or more of the phase circuits being switched, and for successive phases, repeatedly adapting the turn-on time period ton for controlling the length of the pulses of the inductor current IL to minimise a difference from the period length T;
each phase circuit comprising the inductor being connected between the first input terminal and a bridge point, an upper branch switching unit connected between the bridge point and the first output terminal, and the switch with a parallel freewheeling diode being connected between the bridge point and the second input terminal and second output terminal,
the control method comprising the steps of:
determining a number N of phase circuits to be active, N being a positive integer;
determining an initial value for the turn-on time period ton;
determining the period length T;
for at least one of the phase circuits that are to be active:
(A) turning on the switch of the phase circuit, causing an inductor current IL to increase over time, and determining a target turn-on time when the switch shall be turned on a next time;
(B) after the turn-on time period ton, switching off the switch, causing the inductor current
(C) IL to flow through the upper branch switching unit and decrease over time;
(D) after the inductor current IL has returned to zero, at a zero crossing time, turning the switch on again and repeating the steps (A)-(C); and
(E) when repeating the steps (A)-(C), controlling the turn-on time period ton by increasing the turn-on time period ton if the zero crossing time is before the target turn-on time and by decreasing the turn-on time period ton if the zero crossing time is after the target turn-on time.