Role of Modular Multilevel Converters in The Power System

This chapter examines the role of modular multilevel converters in the power transmission systems and power quality improvement. High‐voltage direct current (HVDC) systems are the preferred choice over a high‐voltage AC (HVAC) transmission system for the long distance power transmission. The MMCs can be used as a series and shunt compensator to compensate the reactive power and grid unbalance in the case of power quality improvement. The static synchronous compensator (STATCOM) and unified power quality conditioner (UPQC) are the most popular power quality improvement devices. There are several MMC‐HVDC configurations such as monopolar and bipolar systems in the symmetrical and asymmetrical layouts are available to realize the two‐terminal and multi‐terminal HVDC system. The two‐terminal MMC‐based HVDC system is also referred to as a symmetrical monopolar MMC‐based HVDC system. The symmetrical monopolar configuration has one converter at the sending‐end and one converter at the receiving‐end station.