Fault diagnosis and bounce reduction of electromagnetic actuators require one to obtain the electromechanical transient characteristics (ETCs) in real-time. ETCs can be measured by sensors, but due to their large size and intrusiveness, the approach has its limitations. Acquiring ETCs through finite element method (FEM) could be an alternative, except that FEM is known to be time consuming. In contrast, real-time measurement of coil current is not subjected to these restrictions, yet, it has not been properly utilized for calculating ETCs. In this regard, this paper analyzes the source of the armature kinetic energy, and thus proposes a model based on energy conservation (ECM), describing the relationship between the mechanical and electrical characteristics. Based on the model, ETCs can be calculated from coil current, moving part mass, and the static counterforce. To exemplify the effectiveness of the procedure, an electromagnetic contactor is considered, and the results obtained using the ECM are found fairly consistent with that obtained using sensors. The merit of the proposed ECM lies in its non-intrusive nature and its ability to circumvent the time-consuming FEM in calculating ETCs.

This article presents a paradigm shift in the evaluation of electronic product reliability, a cornerstone in mitigating risks inherent in electrical systems. The accuracy of reliability assessments hinges critically on degradation models, which frame the landscape of analysis. However, the ubiquitous Arrhenius model, despite its merits, encounters limitations in broad temperature applicability, deviating from empirical data beyond a critical threshold. The elusive identification of this threshold challenges, as degradation tests are both time consuming and resource-intensive. Furthermore, the Arrhenius approach struggles with complex data from progressive stress accelerated degradation tests, where nonconstant stress patterns emerge. To address these shortcomings, this groundbreaking study delves into the microscopic mysteries of metal spring stress relaxation, uncovering the fundamental nature of this phenomenon. From this microscopic perspective, this article introduces a novel degradation model, grounded firmly in the error function. The results from exhaustive constant and progressive stress accelerated degradation tests validate the superiority of the proposed model, surpassing the empirical Arrhenius formula in accuracy and reliability. This triumph stems from this model's meticulous consideration of the microscopic dynamics of stress relaxation, offering a more precise and robust framework for electronic reliability analysis.

Degradation models are central to the lifetime prediction of electromagnetic relays. Coefficients of degradation models under accelerated degradation test (ADTs) can be obtained experimentally, and it is customary to map these coefficients back to those describing the actual degradation by the so-called Arrhenius model. However, for some components, such as springs in electromagnetic relays, the Arrhenius model is only appropriate over a certain ADT temperature range, which implies inaccurate mapping outside that range. On this point, an error function model (EFM) is proposed to overcome the shortcomings of the Arrhenius model. EFM is derived from the average vibration energy of the crystal, which is further related to temperature alongside some constants. The empirical part of the paper compares the proposed EFM to the Arrhenius model for the ADT of 28-V–2-A electromagnetic relays. The results show that EFM is superior in describing the temperature characteristics of coefficients in the degradation model. Through mechanism consistency checking, EFM is also shown to be a better option than the Arrhenius model. Moving beyond the case of electromagnetic relays, EFM is thought to have better applicability in the degradation models of capacitors and rubbers.