A Coupled-Inductor Dc Breaker with STFT-Based Arc Detection

Abstract

This paper demonstrates the use of a coupled-inductor dc breaker to isolate the load from the source in case of a shunt fault as well as a slowly developing series arc fault. The design of the breaker allows it to automatically stop conducting in case of a sudden change in output current. The breaker can be designed to ensure that it does not misidentify a desired step change in load current as a fault. In addition a Texas Instruments digital signal processor is used to implement a short-time Fourier transform that continuously analyzes the load current. Based on the frequency content of the signal, the DSP is able to detect a sustained arc and signal the breaker to open. A simulation to demonstrate this concept is included in the paper along with an implementation of the short-time Fourier transform on an experimental setup.