Modular Multilevel Converter

This book reports on a comprehensive study on a novel high-power converter, i.e. a Modular Multilevel Converter with Interleaved Half-bridge Submodules (ISM-MMC). It describes in depth its average model, the operating principles, as well as a new control method and a hybrid modulation strategy that help to exploit the benefits of the interleaving scheme. The new power converter is particularly advantageous for high-current applications that require superb quality of input/output waveforms. Moreover, this book reports on a systematic study of the current balancing problem between parallel-connected units that commutate in non-simultaneous fashion. This is a typical issue in interleaved converters, however here it is analyzed for the first time in relation to MMC-based structures. Two control strategies are proposed to cope with this matter.

by Kamran Sharifabadi (Author), Lennart Harnefors (Author), Hans-Peter Nee (Author), Staffan Norrga (Author), Remus Teodorescu (Author)

With the growth of the installed capacity and the proportion of REG, mainly including wind power and PV power generation, the stable operation of REG and AC/DC transmission systems has become a technical bottleneck for the sustainable development of REG. Since 2009, broadband oscillation incidents have occurred frequently in REG and AC/DC transmission systems in China and some foreign countries, resulting in severe consequences such as large-scale tripping-off of REG units, damaging equipments, and an increasing curtailment of wind and PV power generation. However, there are great difficulties and challenges for the analysis and mitigation of broadband oscillation.

With the growth of the installed capacity and the proportion of REG, mainly including wind power and PV power generation, the stable operation of REG and AC/DC transmission systems has become a technical bottleneck for the sustainable development of REG. Since 2009, broadband oscillation incidents have occurred frequently in REG and AC/DC transmission systems in China and some foreign countries, resulting in severe consequences such as large-scale tripping-off of REG units, damaging equipments, and an increasing curtailment of wind and PV power generation. However, there are great difficulties and challenges for the analysis and mitigation of broadband oscillation.