An adaptive reclosing scheme for flexible DC grid based on residual voltage S-transformation

Area of Science:

• Electrical Engineering
• Power Systems

Background:

• Traditional automatic reclosing schemes struggle with accurate fault identification, risking reclosing onto permanent faults and causing system instability.
• Existing methods lack precision in determining fault arc extinction moments, hindering rapid power restoration.
• Secondary impacts from reclosing onto permanent faults pose a significant threat to power transmission system stability.

Purpose of the Study:

• To develop an innovative adaptive reclosing scheme for power transmission systems.
• To accurately identify fault nature and precisely determine fault arc extinction moments.
• To enhance the safety and reliability of power transmission systems by preventing secondary fault impacts.

Main Methods:

• Proposes an adaptive reclosing scheme utilizing the S-transform of residual voltage.
• Applies electrostatic induction principles to calculate induced voltage before and after fault arc extinction.
• Enhances residual voltage abrupt change characteristics using sum of amplitude squares and mean values.

Main Results:

• The proposed scheme accurately identifies fault nature and precisely determines the arc extinction moment.
• Simulation experiments demonstrate shortened reclosing times for transient faults compared to traditional schemes.
• The method effectively prevents secondary fault impacts caused by reclosing onto permanent faults.

Conclusions:

• The adaptive reclosing scheme offers high convenience and practicality without requiring additional control measures.
• This innovative approach accelerates power supply restoration and significantly improves the safety and stability of power transmission systems.
• The S-transform-based method provides a reliable solution for modern power system protection and operation.