Multi-Physical field coupling effects on reflective Fiber-Optic voltage Sensor: Modeling and quantitative error mechanism analysis

• Developed a multiphysics-coupled FOVS modeling approach. • Clarified thermal drift and vibration error mechanisms. • Proposed an error model predicting < 2 %. • Validated model accuracy by simulation and experiment. • Supports adaptive compensation for real applications. Reflective fiber-optic voltage sensor (RFOVS) based on the inverse piezoelectric effect provide intrinsic insulation and wideband response, making them well-suited for high-voltage measurements in harsh environments. However, their accuracy is considerably compromised by environmental disturbances. This study reveals that temperature fluctuations cause bidirectional, cumulative output drift through thermal expansion and piezoelectric coefficient variations, while mechanical vibration introduces sinusoidal fluctuations proportional to acceleration amplitude and synchronized with stress frequency. A quantitative error model incorporating temperature ramp rate and stress amplitude is established and validated, achieving prediction errors below 5% under extreme conditions and under 2% in typical scenarios. These results advance the understanding of multi-physics coupling mechanisms and offer a practical compensation framework to enhance RFOVS reliability in demanding applications such as railway traction systems and smart grid substations.