US 12,483,159 B2
Controller for controlling a balancer circuit
Sebastian Pedro Rosado, Nuremberg (DE); Zhaohui Wang, Shenzhen (CN); and Francisco Daniel Freijedo Fernández, Nuremberg (DE)
Assigned to Huawei Technologies Co., Ltd., Shenzhen (CN)
Filed by HUAWEI TECHNOLOGIES CO., LTD., Shenzhen (CN)
Filed on Nov. 29, 2023, as Appl. No. 18/523,588.
Application 18/523,588 is a continuation of application No. PCT/EP2021/082422, filed on Nov. 22, 2021.
Prior Publication US 2024/0097550 A1, Mar. 21, 2024
Int. Cl. H02M 7/487 (2007.01); H02M 1/00 (2006.01); H02M 7/483 (2007.01)
CPC H02M 7/487 (2013.01) [H02M 1/0003 (2021.05); H02M 1/0012 (2021.05); H02M 1/0022 (2021.05); H02M 7/483 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A controller for controlling a balancer circuit, the controller being configured to:
determine a difference value between a first direct current (DC) link voltage value across a first DC link of a power converter and a second DC link voltage value across a second DC link of the power converter;
determine a phase-angle and a magnitude of the difference value for an integer harmonic of a predetermined grid frequency;
provide a switching signal for switching between the first DC link and the second DC link based on the phase-angle and the magnitude;
control a mid-point current at a mid-point terminal of the power converter in terms of magnitude and direction based on the switching signal; and
determine a sign for the switching based on the phase-angle of the difference value,
wherein the controller comprises a current control loop configured to control the mid-point current based on the sign and the magnitude of the difference value,
wherein the controller is further configured to:
determine a current control reference value for the current control loop based on the magnitude of the difference value and a measurement value of a converter current processed by the power converter;
determine the current control reference value based on a linear relationship with the measurement value of the converter current within a predetermined range of the measurement value of the converter current; and
set the current control reference value to a predefined value when the measurement value of the converter current is within a range above the predetermined range of the measurement value of the converter current,
wherein the first DC link comprises a first DC link capacitor and the controller is configured to receive a measurement value of a voltage across the first DC link capacitor as the first DC link voltage value,
wherein the second DC link comprises a second DC link capacitor and the controller is configured to receive a measurement value of a voltage across the second DC link capacitor as the second DC link voltage value, and
wherein the balancer circuit comprises:
a first switch configured to switch the first DC link of the power converter based on the switching signal; and
a second switch configured to switch the second DC link of the power converter based on the switching signal.