Sensorless Control of Synchronous Machines with DC-Link Voltage Immunity and Adaptation

Position sensorless techniques have implicit dependence on the DC-link voltage sensor which acts as a single point of failure. This work presents a novel position estimation technique that is immune and resilient to the errors in the DC-link voltage measurement. The proposed sensorless scheme is developed within the projection vector framework from the linearized dynamics of the hybrid flux observer. In addition, a DC-link voltage estimation that is independent and decoupled from the position estimation is developed for a potential DC-link voltage sensorless and position sensorless operation capability. The proposed scheme is validated in simulations on a 5.5 kW permanent magnet assisted synchronous reluctance (PM-SyR) machine.