An Open-Loop Starting Procedure for Sensorless Control of Synchronous Reluctance Motors

This paper presents the development and test of an open-loop start-up procedure for synchronous reluctance motor drives, designed to match the polynomial torque-speed profile of a pump application. The integration of this procedure with a flux-observer allows for relatively easy sensorless operation in those applications that do not require steady-state operation at low or null speed. In particular, the paper focuses on the design of the open-loop control references in order to achieve the maximum acceleration performance and the concerns for a smooth and safe switching towards the closed-loop observer. Real-time simulation and experimental results are presented to prove for the effectiveness of the method.