Open AccessEfficient and accurate hybrid model of modular multilevel converters for large MTDC systems
Author(s) -
Yu Siqi,
Zhang Shuqing,
Wei Yingdong,
Zhu Yanan,
Sun Yubo
Publication year - 2018
Publication title -
iet generation, transmission and distribution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.92
H-Index - 110
eISSN - 1751-8695
pISSN - 1751-8687
DOI - 10.1049/iet-gtd.2017.0756
Subject(s) - thévenin's theorem , converters , modular design , control theory (sociology) , voltage , computer science , electronic engineering , topology (electrical circuits) , equivalent circuit , engineering , electrical engineering , artificial intelligence , control (management) , operating system
Modular multilevel converters (MMCs) play a critical role in the future energy Internet pattern. Therefore, proper models for the simulation of complex systems with multiple MMCs are required. This study proposes a simplified equivalent model (SEM) based on the implicit trapezoidal method and Thevenin equivalent. The model can accurately simulate arm voltages of the MMC and is thus capable of simulating system‐level transients after faults and disturbances, circulating currents and subsynchronous oscillation components. Subsequently, a hybrid model combining SEM and a detailed equivalent model (DEM) is built to improve the overall simulation speed in scenarios where submodule‐level transients are mixed with system‐level ones. Finally, this study notes that the major difference between DEM and SEM results only from the voltage‐balancing cycle. An experiential formula is given to regulate SEM when the voltage‐balancing cycle is large, where the difference may become obvious/insufferable.