Co-Rotational Auto-Resistance Mechanism and Load-Adaptive Recommended Switching Timing Strategy for Dual-State Operation of Single-End Segmented Rotor Induction Machines

Modern intermittent electromechanical drive systems demand reliable heavy-load startup capability, while conventional squirrel-cage induction machines suffer from an inherent trade-off between high starting torque and severe transient inrush current. The single-end segmented rotor induction machine adopts a dual-state operating mechanism to effectively alleviate this contradiction. However, existing studies mainly focus on static electromagnetic performance verification, and load-adaptive recommended switching timing for dynamic operating scenarios remains insufficiently explored, restricting its practical engineering application. This paper addresses this research gap by investigating load-matched switching timing strategies for the proposed dual-state machine. Theoretical modeling of the dual-state operating principle and multi-branch equivalent circuit is performed, combined with finite element simulations and prototype experiments to characterize transient startup and state-transition behaviors at different switching instants and variable loads. The results confirm that the proposed machine reduces startup inrush current by nearly 30% and improves the starting torque multiple by 20% compared with conventional counterparts, based on equivalent-circuit and finite-element analyses. Verified switching rules indicate that pre-synchronization switching best balances light-load transients, whereas under heavy load the winding should be switched as early as the current constraint permits, since delayed switching neither reduces the surge nor shortens startup. This work provides a feasible technical basis for the high-reliability engineering deployment of segmented rotor induction machines in intermittent heavy-load drive systems.