Switching Signals Based Condition Monitoring for Submodule Capacitors in Modular Multilevel Converters

Autor: Zhi Geng, Minxiao Han, Guangyang Zhou
Rok vydání: 2021
Předmět:
Zdroj: IEEE Transactions on Circuits and Systems II: Express Briefs. 68:2017-2021
ISSN: 1558-3791
1549-7747
DOI: 10.1109/tcsii.2020.3040428
Popis: The capacitors are one of the most important com- ponents in modular multilevel converter (MMC). Due to the large numbers of capacitors applied in MMC, the primary technical challenge about the capacitors is reliability. To identify the abnormal capacitors and improve the performance of MMCs, the capacitor condition monitoring strategy is proposed in this brief. In the monitoring algorithm, the relationship of the capacitances in an arm is deduced. The actual and nominal sums of switching signals for submodules (SM) are used to estimate the capacitances. Furthermore, a compensation for dead time is added to enhance the monitoring accuracy. The proposed condition monitoring algorithm not only simplifies the calculation of capacitances with high accuracy, but also has no adverse influence on the normal operation of MMCs. The feasibility of the proposed strategy is verified by the simulation results in MATLAB/Simulink.
Databáze: OpenAIRE