Open AccessUniform carrier‐based PWM method for three‐phase three‐level three‐wire and four‐wire converter system with neutral‐point balancing
Author(s) -
Zhang Zhi,
Zhu Zuhong,
Hu Bihua,
Tang Xiao,
Liu Chang,
Wang Zhiping
Publication year - 2020
Publication title -
iet power electronics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.637
H-Index - 77
eISSN - 1755-4543
pISSN - 1755-4535
DOI - 10.1049/iet-pel.2020.0160
Subject(s) - pulse width modulation , control theory (sociology) , offset (computer science) , voltage , three phase , modulation (music) , computer science , phase (matter) , point (geometry) , current (fluid) , engineering , electrical engineering , control (management) , mathematics , physics , acoustics , geometry , quantum mechanics , artificial intelligence , programming language
In this study, a simple carrier‐based pulse‐width modulation (CBPWM) method is proposed for a three‐phase three‐level neutral‐point‐clamped converter with neutral‐point (NP) balancing, which can be applied to three‐phase three‐wire (TPTW) and three‐phase four‐wire (TPFW) converter systems simultaneously. First, the effect of each switching state for the NP potential in TPTW and TPFW systems is analysed in detail, and a newly NP control strategy by reconstructing the switching state and adjusting the corresponding duration time is deduced for all operation conditions, it only needs to add the offset voltage to the modulation reference voltage to guarantee the NP balance and is easy to implement. Then, under all operating conditions, the mathematical model of NP current is derived and analysed to evaluate the low‐frequency voltage oscillation in the NP. Finally, the effectiveness and feasibility of the proposed CBPWM strategy are verified by the experimental results based on a 12 kVA laboratory prototype.