Design and implementation of a systematically tunable high impedance fault relay

Area of Science:

• Electrical Engineering
• Power Systems Protection

Background:

• High Impedance Faults (HIFs) pose detection challenges in power systems.
• Existing methods struggle with dependability and security, especially under varying feeder conditions.

Purpose of the Study:

• To propose a practical relay algorithm for reliable High Impedance Fault detection.
• To develop a method for determining HIF relay settings that balances dependability and security.
• To enable adaptive tuning of settings based on feeder topology and load.

Main Methods:

• A novel computational algorithm combined with an operational procedure for HIF detection.
• Discrimination based on the analysis of harmonic energy content in current waveforms (existence, steadiness, randomness).
• Implementation of the algorithm on a Digital Signal Processor (DSP).

Main Results:

• The proposed algorithm successfully determines HIF relay settings, maintaining both dependability and security.
• Demonstrated adaptability of settings to changes in feeder topology and load amounts.
• Acceptable security and dependability achieved when validated with field test data and simulation data.

Conclusions:

• The developed relay algorithm offers a practical solution for High Impedance Fault detection.
• The method provides robust performance and can be tuned for dynamic power system environments.
• The DSP implementation facilitates real-time application in power system protection.