TITLE:
Research on the Topology and Control Scheme of an Innovative Modular Multilevel Converter
AUTHORS:
Daixiang Zhu, Ming Ding
KEYWORDS:
Sub-Modular; Modular Multilevel Converter; Fundamental Switching Modulation; Topology; CAPACITOR Voltage Balancing
JOURNAL NAME:
Energy and Power Engineering,
Vol.5 No.4B,
November
21,
2013
ABSTRACT: This paper presents a new modular multilevel converter
(MMC) topology. Compared to conventional multilevel converters, MMC has much
lower switching frequency (50 Hz) resulting in lower switching losses, and
consequently, lower total losses of the transmission system. The fundamental
concept and the applied control scheme are introduced in detail. A modified
multilevel fundamental switching modulation scheme adopting the multicarrier pulse width modulation concept is
presented. A capacitor voltage balancing technique is proposed. With the
established simulation model of the 11-level MMC, the modulation and balancing
strategy presented are confirmed by MATLAB/SIMULINK simulations. The multicarrier pulse width modulation
converter strategy enhances the fundamental output voltage and reduces total
harmonic distortion. This new type of converter is suitable for
high-voltage drive systems and power system applications such as high voltage
dc (HVDC) transmission, reactive power compensation equipment and so on.