US 11,894,782 B2
Pulse Width Modulation method for Cascaded H-bridge converter
Jianxiong Yu, Shanghai (CN); Jiajie Duan, Shanghai (CN); Qiang Chen, Shanghai (CN); Han Li, Shanghai (CN); and Cheng Luo, Shanghai (CN)
Assigned to SANTAK ELECTRONIC (SHENZHEN) CO., LTD., Shenzhen (CN)
Filed by SANTAK ELECTRONIC (SHENZHEN) CO., LTD., Shenzhen (CN)
Filed on Sep. 14, 2022, as Appl. No. 17/932,062.
Claims priority of application No. 202111080594.8 (CN), filed on Sep. 15, 2021.
Prior Publication US 2023/0077401 A1, Mar. 16, 2023
Int. Cl. H02M 7/217 (2006.01); H02M 7/493 (2007.01); H02M 7/00 (2006.01); H02M 1/00 (2006.01); H02M 1/32 (2007.01); H02M 7/483 (2007.01); H02M 7/5395 (2006.01); H02M 3/335 (2006.01); H02M 7/48 (2007.01)
CPC H02M 7/493 (2013.01) [H02M 1/0058 (2021.05); H02M 1/325 (2021.05); H02M 7/003 (2013.01); H02M 7/217 (2013.01); H02M 7/4835 (2021.05); H02M 7/5395 (2013.01); H02M 1/007 (2021.05); H02M 1/0054 (2021.05); H02M 1/327 (2021.05); H02M 3/33573 (2021.05); H02M 7/4807 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A Pulse Width Modulation (PWM) method for a Cascaded H-bridge (CHB) converter, wherein each phase of the CHB converter connected to a three-phase AC power supply is provided with n CHB rectifier circuits, where n is greater than 1, and each CHB rectifier circuit is provided with a first AC input terminal, a second AC input terminal, a positive DC output terminal, a negative DC output terminal, four power transistors connected to form a H-bridge structure, and a DC bus capacitor,
the PWM method comprising the steps of:
S1, generating a pair of sinusoidal signals with a phase difference of 180 degrees as a first reference waveform and a second reference waveform, and generating n carrier signals having sequentially decreasing levels and equal amplitudes to correspond to the n H-bridge rectifier circuits, respectively, wherein the levels of the n carrier signals are cascaded to fill the amplitude of a unipolar voltage half cycle of the reference waveform; and
S2, determining PWM signals for controlling the corresponding H-bridge rectifier circuits based on each reference waveform and each of the n carrier signals, and controlling, by n groups of the PWM signals, the power transistors in the n H-bridge rectifier circuits to switch on and off.