Risk Evaluation for Hybrid Excitation Compulsator

In the field of compulsators, hybrid excitation concepts have been verified through the development of several hybrid excitation prototypes. Although there are some advantages associated with the hybrid excitation compulsator in comparison with the traditional electrical excitation topology compulsator, some drawbacks still exist, which may lead to demagnetization of the permanent magnets and therefore affect the performance and operational safety of such compulsators. For practical applications, the risk of demagnetization needs to be assessed, measurements need to be taken, and design parameters need to be refined. The problem is critical during discharge, with many factors associated with dictating the demagnetizing of these compulsators. In particular, the demagnetizing magnetic strength, temperature rise, and stress effects were analyzed. The temperature distribution in the compensation shield caused by eddy-current losses was simulated. During discharge of a permanent magnet, the location of temperature sources is important. The impact stress imposed on the permanent magnets was simulated and safety characteristics were evaluated.