Stability Analysis of Active Front End and Permanent Magnet Synchronous Generator With Back EMF-Based Sensorless Control for DC Marine Vessels

This paper studies the influence of sensorless control on the permanent magnet synchronous generator (PMSG) and pulse width modulation (PWM) converter (active front end rectifier, AFE) system for dc marine vessels. Back EMF-based sensorless control is adopted in this paper because the minimum speed of PMSG in a dc marine vessel is enough for obtaining a sufficient back EMF signal. Firstly, the output impedance of 'PMSG+AFE' system with a typical topology and controller is deduced by small-signal analysis. The stability analysis with constant power load (CPL) is analyzed, including the influence of sensorless control bandwidth on PMSG with a significant per-unit impedance value. Since the inductance parameter affects both the current control and sensorless control, the influence of error in the estimated inductance parameter on the stability of 'PMSG+AFE' system is analyzed. To verify the proposed impedance model, output impedance is measured in the simulation and experiment. The stability analysis with the proposed impedance model and load impedance of CPL is provided in Matlab, and simulation results and experimental measurements are given to verify the analysis.