Xiaoming Yu1, Peng Wang1, Jun Wang1, Zhijun Chen1, Ke Zhang1, Duicheng Zhao2, Jiapeng Shen2, Chuyang Wang2,*, Li Zhang2
Energy Engineering, Vol.123, No.6, 2026, DOI:10.32604/ee.2026.073475
- 27 May 2026
Abstract Electrolytic capacitors in Modular Multilevel Converter-based Unified Power Flow Controllers (MMC-UPFC) are prone to parameter degradation, significantly affecting system reliability. Accurate identification of their degradation parameters—capacitance (C) and equivalent series resistance (ESR)—is essential for equipment health management. This study proposes a non-intrusive degradation parameter identification method for electrolytic capacitors in MMC-UPFC full-bridge submodules based on digital twin technology and an improved intelligent optimization algorithm. First, the degradation mechanism of electrolytic capacitors under long-term operational conditions is systematically analyzed. Second, a high-fidelity digital twin model integrating the main circuit, sampling circuit, and modulation circuit of the… More >