Analysis of pulsation concentration effect related to sorting-algorithm-based voltage-balancing strategy in an MMC system

A capacitor voltage self‐balancing method of modular multilevel converters based on switching state matrix construction

“…Research on capacitor voltage balancing strategies in recent years mainly includes four categories [5] 1. The first category refers to capacitor voltage balancing strategies based on submodule capacitor voltage sort-ing algorithms [6], including conventional bubble sorting algorithm [7], quick sorting algorithm [8][9][10], grouping sorting algorithm [11][12][13][14], and other optimized sorting algorithms [15][16][17][18]. These studies mainly focus on improving sorting efficiency and reducing switching frequency, whereas sacrificing capacitor voltage balancing effects to some extent.…”

“…Given the cascade structure topology of MMC, capacitors in the DC link are distributed in submodules; thus the capacitor voltage balance control consumes lots of computing resources and reducing converter system reliability, especially for a large number of submodules. Research on capacitor voltage balancing strategies in recent years mainly includes four categories [5] The first category refers to capacitor voltage balancing strategies based on submodule capacitor voltage sorting algorithms [6], including conventional bubble sorting algorithm [7], quick sorting algorithm [8–10], grouping sorting algorithm [11–14], and other optimized sorting algorithms [15–18]. These studies mainly focus on improving sorting efficiency and reducing switching frequency, whereas sacrificing capacitor voltage balancing effects to some extent.…”