电力系统保护与控制2025，Vol.53Issue(10)：1-12,12.DOI:10.19783/j.cnki.pspc.241034
一种模块化多电平直流变压器的欠阻尼振荡抑制策略
Underdamped oscillation suppression strategy for modular multilevel DC transformers
摘要
Abstract
The modular multilevel DC transformer(MMDCT)exhibits underdamped characteristics because of the primary side series-connected submodule capacitors,arm inductors and parasitic resistors.This often leads to frequent and persistent underdamped oscillations in actual operation,posing challenges to the safe and reliable operation of the system.To address this issue,an equivalent circulating current model of the primary side of the MMDCT is first established,revealing the mechanism behind the occurrence of underdamped oscillations.Second,a small correction angle is introduced to adjust the circulating current suppression voltage every half switching cycle,which actively controls the circulating current's variation trend and effectively enhances the internal damping of the system,thus suppressing the underdamped oscillations in the transient process.A power feedforward-capacitor voltage and circulating current dual-loop control strategy is adopted.With proper parameter design,the system ensures good dynamic response performance in various scenarios and operating conditions.Finally,the effectiveness of the proposed control strategy in mitigating the underdamped characteristics of the MMDCT is verified through simulations and experiments.关键词
模块化多电平直流变压器/欠阻尼振荡/振荡抑制/动态响应性能Key words
modular multilevel DC transformer/underdamped oscillation/oscillation suppression/dynamic response performance引用本文复制引用
李政,孙毅超,鄢寅宇,杨熊,季振东,吕丹..一种模块化多电平直流变压器的欠阻尼振荡抑制策略[J].电力系统保护与控制,2025,53(10):1-12,12.基金项目
This work is supported by the National Natural Science Foundation of China(No.52277188). 国家自然科学基金项目资助(52277188) （No.52277188）
