Principle of Arc Fault Detection for Solid State Power Controller

Solid state power controllers (SSPC) are semiconductor devices that control electrical power (voltage and/or current) supplied to a load. They perform supervisory and diagnostic functions in order to prevent overload conditions and short circuits. There are several basic types of solid state power controllers. SSPC controllers are designed to switch both AC and DC voltages. The SSPC is increasingly used in avionics systems primarily due to the emergence of the All Electrical Aircraft. Here we present the main differences between the SSPC and a relay associated to a circuit breaker. As the need for electric power has increased significantly and as the demand will be even higher in the future, then a need to protect the equipment against arc fault is becoming a major issue for safety in aviation. In this paper we present a microprocessor based SSPC which is able to detect the presence of an electrical arc in a circuit. We also describe a multi-algorithm detection architecture and we show how it is possible with this architecture to detect around 75 percent of arc faults occurring in a circuit. The results are obtained using a test bench described in this article.