Experimental Investigation of Typical Mechanical Faults in 10 kV Vacuum Circuit Breakers and Multimodal Signal Analysis

A 10 kV vacuum circuit breaker mechanical fault simulation platform was constructed to acquire multimodal signals, including transient voltage and current, driving current, and vibration, under fault scenarios such as spring fatigue, bolt loosening, and linkage jamming. From the transient voltage and current waveforms, features such as oscillation duration, peak value, chopping current, total harmonic distortion, and transient arc impedance were extracted to analyze the influence of different mechanical faults on arc evolution. Efficient signal decomposition methods, including empirical mode decomposition, were employed to enhance time–frequency resolution and robustness against disturbances. Comparative analysis of the extracted features revealed electro–mechanical coupling mechanisms: spring fatigue reduces opening speed and enhances high-frequency oscillation responses; bolt loosening extends oscillation duration and increases signal instability; linkage jamming results in delayed mechanical response and intensified abnormal oscillations. These findings provide both data support and characteristic analysis methods for non-intrusive diagnosis of mechanical faults in vacuum circuit breakers.