A Robust Wound-Rotor Synchro Design With a Compensation Winding for Fault-Tolerant Operation

Wound-Rotor (WR) synchros are critical components in aerospace and industrial applications, yet their accuracy is highly susceptible to mechanical and electrical faults. This paper introduces a novel and robust WR synchro design incorporating a short-circuited compensation winding (SCCW) to enhance fault tolerance and overall reliability of WR synchros. A key advantage of this technique is its universality: as an add-on solution, the SCCW can be integrated into various WR topologies (including radial-flux, axial-flux, and linear types) without requiring core redesign, regardless of pole or slot count. The proposed SCCW is specifically designed to mitigate the detrimental effects of rotor eccentricities, short-circuit faults, and particularly the leakage flux from the associated Rotary Transformer (RT). The performance of this fault-tolerant design was comprehensively evaluated through 3-D Time-Stepping Finite Element Analysis (TSFEA). In the presence of the RT, results demonstrate the SCCW's effectiveness; for instance, under a 50% static eccentricity fault, the proposed design reduced the Average Absolute Position Error (AAPE) by 94%. To validate the analysis, a prototype of the proposed sensor was fabricated and experimentally tested. The experimental measurements are in good agreement with the 3-D TSFEA results, confirming the validity of the findings.