S-Transform-Based Fault Detection Algorithm for Distance Protection on FPGA

Abstract

With the replacements of coal and nuclear plants with renewable energy sources such as Type-3 and Type-4 wind turbines and photovoltaic system, the fault current levels of the electrical power system become lower. This leads to a weakened ability of the commercial distance relays to detect fault currents. Therefore, new fault detection algorithms have been developed based on different approaches with the intention of raising the ability to detect faults under different circumstances. Among them, Stockwell Transform has been proved to be a useful tool to determine the occurrence of faults. This thesis presents an FPGA implementation of one of the newly developed S-Transform-based fault detection system on Zynq device. The conceptual methods of building an IEC communication interface to connect the system to an RTDS are investigated.
The algorithm on hardware is implemented in fixed-point representation, fully parameterized, and fully pipelined with the operation frequency at 100MHz. The final implementation is able to provide the result within 570ns. The hardware implementation of the S-Transform-based fault detection system is tested with simulations proving it can perform identically with the MATLAB model of itself.