Fault Severity Estimation Method for Mechanical Parts in Circuit Breakers Based on Vibration Analysis

How to effectively identify the fault severity for mechanical parts in high-voltage (HV) circuit breakers (CBs) is an unsolved issue so far. To address this issue, this paper proposes a fault severity identification method using morphological characteristics of chaotic attractor of CB vibration signal. First, in order to accurately extract the weak fault features for the early fault mechanical parts, the vibration signals are firstly divided into several sub-signals according to the CB's operation sequence. Then we propose an adaptive signal decomposition method for separating the mode components from the divided sub-signals. Finally, the chaotic attractor of the mode component is reconstructed and the fault severity of mechanical part is diagnosed by the morphological characteristics of the attractor. The experimental results of two different types of CBs show that the chaotic attractor is highly sensitive to the severity of fault, and that the shape of the attractors in normal and faulty states is significantly different. The shape of the attractor varies with the aggravation of the fault severity. This method could provide a new way to identify the fault severity for mechanical partsin HVCB. © 2021, Electrical Technology Press Co. Ltd. All right reserved.