Arc fault protection for more electric aircraft application

Abstract

In aircraft applications, arc faults can be hazardous and could lead to fire. Several recommendations have been made to improve aircraft wiring safety, including the development of arc fault circuit protection for wiring systems. This project focuses on developing an arc fault detection unit (hardware/software) to be included in a Solid-State Power Controller (SSPC) with the ability to differentiate between normal fault current and arc current with the immunity to normal load start-up transients. An arc detection evaluation board by Texas Instruments (TI) – RD 195 is analyzed and a corresponding MATLAB code is developed for the algorithm proposed by them. Firstly, to understand the working of the hardware analog circuits embedded on the board, they were simulated using SIMETRIX/LT-SPICE software and the respective output waveforms were captured. Also, these circuits were tested manually (hardware testing) by sending in a preset signal from signal generator and capturing the corresponding waveforms using oscilloscope. The hardware, software and calculated results were compared and tabulated for simplified understanding of the board. Secondly, a MATLAB code was developed for the given algorithm by TI with few enhancements to improve its sensitivity in distinguishing load transients and arcing cases. The developed MATLAB code is tested with several load current samples collected during arcing, no arcing and load transient scenarios. This report elaborates on the: 1. Arc generation circuit – The hardware setup used to generate arc and collect the current samples to be tested during arcing condition. 2. The hardware analysis of the TI RD-195 arc detection evaluation board. 3. Detailed flowchart of the arc detection algorithm used by TI. 4. Developing and testing of the MATLAB code representing the corresponding algorithm.Bachelor of Engineerin