Year: 2025
Type: article
Abstract: The modular multilevel matrix converter (M3C) can perform AC/AC conversion directly. However, M3C operation often requires a pre-charging process, which can be challenging due to the need for fast pre-charging with low inrush current. To address the issue, a closed-loop fast pre-charging strategy is proposed that utilizes an improved nearest level modulation (NLM) based on a quick-sorting algorithm for M3C. By improving the current limiting resistor and the number of Sub-Modules (SMs) inserted into the NLM, we achieve a reduction in inrush current when connected to the grid, and unlock the control algorithm, respectively. This paper presents the relationship between the current-limiting resistor, the pre-charging current, and the pre-charging time. Reactive power compensation is applied on the AC grid during the pre-charging process to ensure stability. Furthermore, the balanced control of capacitor voltage is employed to achieve synchronized and coordinated growth of capacitor voltages in SMs using a quick-sorting algorithm based on NLM. The simulation and experimental results demonstrate the effectiveness of this approach, making it suitable for M3C with a high number of SMs.
Source: Energies
DOI: 10.3390/en18112895
Authors: Rufei He, Yikai Li, Yumin Peng, Yiming Ma, Fanqi Huang, Hailong Li, Wei Luo
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,137
Funder: China Southern Power Grid
OpenAlex ID: W4410960424