Impact of Power-Sharing Capability to Inter-Turn Short Circuits in Multiphase Synchronous Drives

This article presents an advanced modeling framework for inter-turn short circuits (ITSCs) in segmented permanent magnet synchronous machines (PMSMs), with a focus on highly coupled segmentation (HCS) and multisector segmentation (MSS) winding architectures. As electric traction systems increasingly demand compactness and reliability—especially in aeronautics, electric vehicles, and renewable energy—ITSCs remain a critical failure mode, often leading to severe short-circuit currents and potential system collapse. While multiphase systems enhance fault tolerance for open-circuit faults, ITSCs pose unique challenges due to their propensity to propagate within motor windings.
The study introduces a model that systematically analyzes ITSC faults in PMSMs operating under power-sharing conditions. Validated through experimental data from a dedicated laboratory test bench, the model demonstrates a strong alignment with real-world observations. A key innovation is the decoupling of intrinsic motor behavior (e.g., torque production and magnetic flux control) from the impact of power-sharing strategies, revealing how short-circuit currents are influenced by both resistive and inductive terms highly dependent on the segmentation technology.
Comparative analysis highlights that MSS configurations exhibit greater sensitivity to power-sharing variations than HCS. This sensitivity stems from disparities in magnetic coupling: minimal in HCS but pronounced in MSS, where differential inductances significantly affect short-circuit currents. The findings underscore that while HCS maintains stability under power-sharing adjustments, MSS requires careful control to mitigate fault propagation risks.
The model’s predictive capabilities—spanning speed, short-circuit resistance, and differential current variations—provide actionable insights for designing fault-tolerant, power-sharing-capable drives. This work advances the understanding of ITSC dynamics in segmented PMSMs, offering a robust foundation for optimizing motor resilience in high-reliability applications.