Sensorless standstill commissioning of synchronous reluctance machines with automatic tuning

This paper deals with the sensorless selfcommissioning of synchronous reluctance motors at standstill. Previous work demonstrated that the injection of high test voltage pulses can be successfully used to determine the flux linkage maps of the Synchronous Reluctance machine without position transducer and with no need of rotor locking. In this work, the tuning aspects of the above self-commissioning technique are analyzed for making it self-tuning. A method for detecting unwanted rotor movement during the test is introduced and used to assess the test’s end and to maximize the id, iq area of inspection. Furthermore, the paper analyzes a number of theoretical and practical implementation issues, first mathematically and then in experiments. The effects of possible error sources are evaluated, including imprecise estimation of the stator resistance and of the inverter voltage distortion, and iron loss. Experimental results are presented for three Synchronous Reluctance motor prototypes.