A nonlinear observer for DC bus voltage estimation and sensor diagnosis for a battery charger used in automotive systems

This paper describes an observer for the diagnosis of the DC link voltage sensor for an electrical drive composed of a Permanent Magnet Synchronous Machine (PMSM) and a 3H bridge level grid connected inverter. The dynamics of the DC Voltage is function of duty cycles and the phase currents. Then, the observer can be used in a Fault Tolerant Control scheme to detect a DC link voltage sensor fault. The global convergence of the observer is demonstrated and simulation results show the effectiveness of the method. Experimental data processed offline confirm the efficacy of the proposed approach.