Open AccessDC‐link capacitor voltage balance strategy of independent double three‐phase common bus five‐level NPC/H‐bridge inverter based on finite control set
Author(s) -
Wei Wang,
Guangsen Wang
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.2019.1131
Subject(s) - voltage , control theory (sociology) , inverter , capacitor , capacitance , h bridge , three phase , computer science , engineering , electrical engineering , control (management) , physics , electrode , quantum mechanics , artificial intelligence
This study aims at the DC‐link capacitor voltage imbalance problem of independent double three‐phase common bus five‐level neutral point‐clamped/H‐bridge inverter, which is applied to an electromagnetic launch system under instant high‐power and high‐current conditions. First, the traditional method of voltage balance strategy based on redundant vectors is described, and the key factors leading to the DC‐link capacitor voltage fluctuation is analysed in detail. Second, the objective function is constructed to predict the variation trend of DC‐link capacitance voltage difference. Third, an optimised voltage balance strategy is proposed. At first, the optimised strategy calculates the variation trends of the voltage difference for all three‐phase switch vector combinations. Then, the results make up a voltage balance finite control set. At last, compare the results in the set to select the vector combination corresponding to the minimum variation for output. Finally, tested by the semi‐physical real‐time simulation platform, and the proposed optimised voltage balance strategy is verified effective for improving DC‐link capacitor voltage imbalance and inhibiting the voltage difference fluctuation.