Time‐Varying Reliability Assessment of SPCU Electronics Under Mission Profile Uncertainties

ABSTRACT The satellite power control unit (SPCU) is a vital component within spacecraft power management systems, ensuring precise regulation of bus voltage and current. Its operational reliability is pivotal to maintaining the overall stability of the spacecraft's power system. However, conventional reliability assessment methods, which primarily rely on stress proportionality, often result in substantial inaccuracies, limiting their effectiveness in accurately evaluating component reliability. While existing studies have incorporated mission profile considerations into reliability assessment frameworks, they generally neglect the intrinsic uncertainties associated with performance degradation. Therefore, this paper proposes a novel time‐varying reliability assessment framework for SPCU components that simultaneously accounts for mission profile uncertainty and degradation effects. This methodology comprises the following steps: (1) analysis of component failure mechanisms and sources of mission profile uncertainty; (2) construction of a hybrid reliability assessment model that combines Kriging surrogate modeling with multi‐physics simulations; and (3) execution of a time‐varying reliability analysis for SPCU components. A case study further validates the rationality and feasibility of the proposed framework in comparison with conventional methods.