Coordinated Control Strategy for Fault-Blocking of Modular Multilevel Converter in Hybrid Cascaded Ultra High Voltage Direct Current Transmission Systems Based on Protection Signal
- Resource Type
- Conference
- Authors
- Cheng, Haotian; Shen, Jiangming; Liu, Zhongping; Ye, Hai; Liu, Hulin; Han, Jun; Zheng, Xiaodong; Tai, Nengling
- Source
- 2023 5th Asia Energy and Electrical Engineering Symposium (AEEES) Energy and Electrical Engineering Symposium (AEEES), 2023 5th Asia. :578-586 Mar, 2023
- Subject
- Power, Energy and Industry Applications
Fault diagnosis
Surge protection
Rectifiers
Optimal control
Switches
High-voltage techniques
Receivers
HC-UHVDC
overcurrent and overvoltage
control strategy
protection signal
- Language
For the abnormal phenomenon of non-faulty MMC after fault MMC blocking in Hybrid Cascaded Ultra High Voltage Direct Current (HC-UHVDC) transmission system, a coordinated control strategy based on control signals is proposed. The mechanism of overcurrent and overvoltage in non-fault MMC was analyzed. Additional current was added in the LCC rectifier control to suppress overcurrent and overvoltage. DC voltage is out of control when the MMC master station is fault-blocked. To solve this problem, an optimal control strategy is adopted to convert the slaver station to the new master station. The scheme is based on the protection signal to identify the fault converter station. After the converter station is blocked, the system can be safely and effectively restored to the stable state.