A protection method for multi-terminal HVDC system based on fuzzy approach.

Area of Science:

• Electrical Engineering
• Power Systems
• Control Systems

Background:

• Voltage Source Converter (VSC)-based Multi-Terminal High Voltage Direct Current (MT-HVDC) systems are crucial for modern power grids.
• Effective fault detection and localization are essential for the reliability and stability of these systems.
• Existing methods may require complex communication infrastructure or extensive measurements.

Purpose of the Study:

• To develop a robust and efficient fault detection, identification, and localization method for VSC-MT-HVDC systems.
• To propose a system utilizing only rectifier-end measurements, eliminating the need for communication links.
• To implement a Fuzzy Inference System (FIS)-based approach for enhanced system protection.

Main Methods:

• A Fuzzy Inference System (FIS) comprising three modules (FIS-1, FIS-2, FIS-3) was developed.
• FIS-1 detects AC or DC segment faults; FIS-2 identifies the faulty section; FIS-3 recognizes the faulty pole.
• The method relies solely on rectifier-end voltage and current signal measurements.

Main Results:

• The proposed FIS-based method enables rapid fault detection within the MT-HVDC system.
• The system successfully identifies the specific fault location and the faulty pole.
• The method was validated in a simulated MT-HVDC system using MATLAB.

Conclusions:

• The FIS-based fault detection method offers a simple, effective, and implementable solution for VSC-MT-HVDC systems.
• Utilizing rectifier-end measurements simplifies protection strategies and reduces reliance on communication.
• This approach enhances the overall security and operational efficiency of MT-HVDC grids.