High-performance Sensorless Control Strategy of High-speed Maglev Based on Nonlinear Extended State Observer and Improved Phase Lock Loop

This paper proposes a high-performance sensorless control strategy of high-speed maglev based on nonlinear extended state observer and improved phase lock loop (PLL). A NESO with fast convergence speed and strong anti-disturbance ability is proposed to observe the back electromotive force. A Lyapunov function is designed to prove that the NESO can converge to the equilibrium point in a finite time. A disturbance estimation and compensation term is added to the conventional PLL to achieve zero steady-state error tracking when subjecting to a frequency ramp input. Simulation results show that the angle observation error is less than 0.033 rad at 50 km/h and less than 0.1 rad at 600km/h.