Improved sliding-mode control for MMC in DC power system
Improved sliding-mode control for MMC in DC power system
复制标题
直流电源系统中MMC改进滑模控制
DOI：
10.1049/iet-rpg.2020.0493
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发表时间：
2020
影响因子：
2.6
通讯作者：
Guan Tianyi
中科院分区：
文献类型：
--
作者：
Li Bin;Xie Yingzhou;Wen Weijie;Guan Tianyi
基于模块化多电平换流器的直流电力系统是一个动态平衡系统，对模块化多电平换流器的控制对于实现有功功率和无功功率的瞬时平衡至关重要。到目前为止，直流电力系统中广泛使用外环、内环和环流控制器的控制架构，这些控制器要求具有良好的动态响应和鲁棒性。然而，基于现有比例积分（PI）控制或传统滑模控制（SMC）的控制器具有不令人满意的性能。因此，在本研究中，提出了一种改进的SMC方法用于内环和环流控制器。与PI控制和常规滑模控制相比，改进滑模控制具有更好的动态响应和鲁棒性，并能有效抑制抖振现象。在电力系统计算机辅助设计/含直流电磁暂态（PSCAD/EMTDC）中建立了四端MMC-DC系统的仿真模型，在此基础上，对PI控制、传统SMC和改进SMC在稳态、功率阶跃大扰动等典型工况下的性能进行了比较，验证了改进SMC的可行性和优越性。
The modular multi‐level converter based direct current (MMC‐DC) power system is a dynamic equilibrium system, and the control of MMC is quite important to realise instantaneous balance of active and reactive power. Until now, the control architecture with outer‐loop, inner‐loop and circulating current controllers is widely used for MMCs in the DC power system, and these controllers are required to have excellent dynamic response and robustness. However, controllers based on existing proportional–integral (PI) control or conventional sliding‐mode control (SMC) have unsatisfactory performances. Therefore, an improved SMC method is proposed in this study for inner‐loop and circulating current controllers. Compared with PI and conventional SMC, the improved SMC has better dynamic response and robustness performance and can suppress chattering phenomenon substantially. The simulation model of a four‐terminal MMC‐DC system is established in power systems computer aided design/electromagnetic transients including DC (PSCAD/EMTDC), based on which, comparison between PI control, conventional SMC and the improved SMC under typical working conditions, e.g. steady state, large disturbances of power step, is conducted, and the feasibility and superiorities of the improved SMC are verified.