Kai Wang1,2,3, Haifeng Guo1,2,3,4,5, Aidong Xu1,2,3 and Michael G. Pecht6
1 DepartmentKey Laboratory of Networked Control Systems, Chinese Academy of Sciences, Shenyang 110016, China
2 Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016, China
3 Institutes for Robotics and Intelligent Manufacturing, Chinese Academy of Sciences, Shenyang 110169, China
4 University of Chinese Academy of Sciences, Beijing 100049, China
5 Liaoning Institute of Science and Technology, Benxi 117004, China
6 Center for Advanced Life Cycle Engineering, University of Maryland, College Park, MD 20742, USA
Electromagnetic coils are a key component in a variety of systems and are widely used in many industries. Because their insulation usually fails suddenly and can have catastrophic effects, degradation monitoring of coil insulation systems plays a vital role in avoiding unexpected machine shutdown. The existing insulation degradation monitoring methods are based on assessing the change of coil high-frequency electrical parameter response, whereas the effects of the insulation failure mechanisms are not considered, which leads to inconsistency between experimental results. Therefore, this paper investigates degradation monitoring of coil insulation systems under thermal loading conditions from a creep point of view. Inter-turn insulation creep deformation is identified as a quantitative index to manifest insulation degradation changes at the micro level. A method is developed to map coil high-frequency electrical monitoring parameters to inter-turn insulation creep deformation in order to bridge the gap between the micro-level and macro-level changes during the incipient insulation degradation process. Thermally accelerated tests are performed to validate the developed method. The mapping method helps to determine the physical meaning of coil electrical monitoring parameters and presents opportunities for predictive maintenance of machines that incorporate electromagnetic coils.