Online Monitoring Method for Piezoelectric Capacitive Voltage Transformer Based on PHM Model

Piezoelectric capacitive voltage transformers are susceptible to environmental factors in high-precision voltage measurement in power systems, leading to issues such as capacitance parameter drift and insulation resistance degradation, which result in maintenance blind spots and high costs associated with regular power outage inspections. To address these issues, this paper proposes an online monitoring strategy for piezoelectric capacitive voltage transformer based on a PHM model. This strategy combines self-disturbance-resistant control methods to dynamically observe multi-source disturbances in the transformer’s operation through an extended state observer, and converts the total system disturbance (including potential faults) into observable temporal feature quantities. Simultaneously, through the self-disturbance-resistant disturbance compensation mechanism, measurement errors caused by parameter drift are corrected online. Simulation verification demonstrates that the observer can accurately track disturbance and fault trajectories even under strong noise conditions.