Open AccessHybrid converter topologies for dc transmission systems
Author(s) -
Adam Grain Philip,
Alsokhiry Fahad,
Abdelsalam Ibrahim,
Fletcher John,
Xu Lie,
AlTurki Yusuf
Publication year - 2019
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.2018.5100
Subject(s) - converters , capacitor , transient (computer programming) , modular design , topology (electrical circuits) , engineering , ćuk converter , electronic engineering , voltage , matlab , electrical engineering , computer science , operating system
This study presents types 1 and 2 hybrid converters with reduced power circuit complexity compared with the mixed cell modular multilevel converter (MC‐MMC). The type 1 converter is formed by replacing the director switches of the alternate arm converter by high‐voltage (HV) half‐bridge (HB) cells rated for half of the dc‐link voltage. Also, it resembles special case of MC‐MMC, where the entire HB cells of each arm are lumped into a single HV HB cell, with both capacitors of the half‐ and full‐bridge cells are exposed to fundamental current as in the conventional MMC. The upper and lower arms of the type 2 converter resemble a front‐to‐front connection of two three‐phase hybrid cascaded two‐level converters, where the cell capacitors of the three‐phase two‐level converters that act as director switches do not experience fundamental currents. Therefore, the type 2 converter offers compact design compared with type 1 converter and the MC‐MMC. The technical viabilities of the proposed hybrid converters are assessed using simulations, with both converters modelled in MATLAB–Simulink using electromagnetic transient simulation approach, considering normal and transient conditions. Experimental results obtained from single‐phase type 1 converter confirm the practical viability of the proposed converters.