A general decentralized control scheme for medium-/high-voltage cascaded STATCOM

• Main Authors: Hou, Xiaochao, Sun, Yao, Han, Hua, Liu, Zhangjie, Su, Mei, Wang, Benfei, Zhang, Xin
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2020
• Subjects: Engineering::Electrical and electronic engineering; Cascaded STATCOM; Decentralized Control
• Online Access: https://hdl.handle.net/10356/141494
• Institution: Nanyang Technological University

This study presents a general decentralized control scheme for cascaded H-bridge inverter-based static compensators in medium-/high-voltage power network. The H-bridge modules are controlled in a decentralized manner without a central controller and each module makes decisions based on individual local controller. The local controller includes two parts: First, a Q-ω boost control is introduced to share reactive power equally; and second, a scalable P-V control is established for balancing dc-link voltage of inverters. The proposed scheme can achieve frequency synchronization autonomously, and thus has advantages of improved reliability, scalability, and decreased costs. Moreover, an improved decentralized control is also proposed to adapt the grid-side dynamics when contingencies will occur. The system stability conditions are derived, and the feasibility of the proposed method is verified by simulation results.