Abstract

Synchronous Reluctance (SynRel) machines are extensively used in high efficiency speed control applications. Magnetic saturation has an important effect on the dynamic performance of the SynRel machine. This phenomenon causes a non-linear relationship between the current and the magnetic flux linkage of each phase of the electromechanical converter. This non-linearity and the rotor anisotropy, greatly affects the inductances waveform as a function of the rotor angular position, far from the sine wave considered by the classical linear approach. In this paper, the variations of the inductances produced by both the saturation and the rotor anisotropy are investigated. To characterize the inductances, a two-dimensional planar finite element model of a transverse laminated, two pole pairs, 40 kW, SynRel machine is implemented using the open source software Finite Element Method Magnetics (FEMM). A SynRel model in natural coordinates and an online parameter correction technique are proposed, allowing to study and analyse the dynamic performance of the machine under saturated conditions. A case study is presented to observe the effect of saturation on the machine’s variables when using a predictive control drive based on Direct Torque Control (DTC) principles. The results demonstrate that the proposed SynRel machine’s model in conjunction with the online parameters correction method are capable of adequately incorporating the magnetic saturation in transient studies.