The evaluation method of SEU effect on relay protection devices

With the continuous upgrading of chip processes, the probability of single event upset (SEU) in chips induced by atmospheric neutrons has greatly increased for the relay protection devices (PDs). Incorrect action cases of PDs caused by SEU effects have been frequently reported. Existing studies mainly focus on the occurrence mechanism of the SEU effect in PDs and also consider the potential problems and corresponding solutions. However, the quantitative evaluation of the PDs’ incorrect action rate due to SEU effects is rarely addressed. In fact, the incorrect action of PDs caused by SEU effects is a probabilistic event. To accurately evaluate the reliability of PDs’ action performance, this paper proposes a method for calculating the incorrect action rate considering the SEU effects. Firstly, the SEU effects of the core chips used in PDs and their impact on the overall PDs’ action performance are analyzed. Based on this, the key chips that are sensitive to the PDs’ action performance are identified, considering the SEU effect. Then, a calculation method for evaluating the incorrect action rate of PDs is proposed, taking into account the failure rate of sensitive chips and the fault propagation mechanism between the chips. Finally, the feasibility of the proposed method is verified by comparing the theoretical calculation results with the irradiation test results. This research is important for determining the reliability of PDs and identifying potential issues due to the iterative improvement of the chips.