Relay protection devices that use advanced integrated circuits are increasingly exposed to soft errors caused by atmospheric neutrons and α particles. This work presents a fault injection method that uses radiation transport simulations to evaluate the soft error response of a commercial line protection device. Geant4 simulations of atmospheric neutrons and package α sources were used to estimate single-event upset rates and obtain the spatial distributions of single-bit and multi-bit upsets in on-chip memory. These data define the number, type, and location of bit flips injected by a host and agent software framework running on the target device without hardware modification. Tests on an NSR-3611 relay protection device showed that only about 4.7% of the total 830 injected faults lead to observable malfunctions, defined as erroneous outputs or execution interruptions. Multi-bit upsets caused by α particles are more likely to generate erroneous outputs than to stop execution. The approach provides a low-cost and repeatable method to emulate safety-relevant failure modes and guide the hardening of relay protection systems.
Yu et al. (Sun,) studied this question.