Synchronous Reluctance Motor Parameter and State Estimation Using Extended Kalman Filter and Current Derivative Measurement

The synchronous reluctance motor is becoming a very attractive alternative to the AC induction machine. This is due to the lack of rare-earth metals in their construction and a higher efficiency, which was brought about by recent progress in rotor design. However, in order to achieve an efficient and low-cost operation of the synchronous reluctance motor drive, an adaptive sensorless algorithm should be utilized to cope with machine non-linearities. This paper describes an adaptive observer, which can provide an estimation of rotor position and speed, as well as core loss and inductance parameters. A modified PWM switching scheme and a current derivative measurement method are proposed, together with an extended Kalman Filter design. Experimental results are shown to demonstrate method performance and feasibility.