Tension–speed control for transformer insulation-layer winding based on Hamiltonian theory

Abstract

During the winding process of transformer insulation layers, strong nonlinear coupling between tension and speed makes the system highly sensitive to external disturbances. This paper presents a tension–speed coordinated control strategy based on feedback dissipative Hamiltonian theory. A nonlinear dynamic model incorporating the unwind roller, rewind roller, and swing-arm mechanism is developed, and the total system energy is formulated through a Hamiltonian energy function. Using the energy shaping and dissipation assignment, an outer-loop feedback controller is designed to achieve stable decoupled control under multiple operating conditions. To further improve robustness and dynamic performance under uncertain disturbances, an inner-loop control algorithm combining a nonlinear disturbance observer and command-filtered backstepping control is introduced for real-time disturbance compensation. Simulations and physical winding experiments were conducted at a rated speed of 60 r/min for three reference tensions (20 N, 30 N, and 50 N) under ±5 r/min speed-step disturbances. Results show that, compared with conventional cascaded proportional–integral–derivative (PID) control, the proposed method reduces tension overshoot from 3.1 to 1.4 N, steady-state error from ±2.0 to ±0.5 N, and response time from 0.45 to 0.29 seconds, achieving about 35% improvement in dynamic performance. Further comparison with a nonlinear proportional–integral–derivative (NPID) controller demonstrates roughly a 50% reduction in overshoot and a 45% improvement in steady-state accuracy. Overall, the proposed Hamiltonian-based control approach provides high precision, strong robustness, and excellent real-time performance for industrial transformer insulation-layer winding systems.