A 250kW transverse-laminated Synchronous Reluctance motor

Throughout the last 15 years, synchronous reluctance (SyR) motor drives have been presented as a competitive alternative to induction motor (IM) drives in many variable speed applications, at least in the small power range. Very few examples of SyR motors above the 100 Nm torque size are present in the literature. The main advantage of the SyR motor lays in the absence of rotor Joule losses that permits to obtain a continuous torque that is higher than the one of an IM of the same size. The paper presents a 250 kW, 1000 rpm synchronous reluctance motor for industrial applications and its performance comparison with an induction motor with identical stator. The rotor of the SyR motor has been purposely designed to fit the stator and housing of the IM competitor. The experimental comparison of the two motors is presented, on a regenerative test bench where one the two motors under test can load the competitor and vice-versa. The results of the experimental tests confirm the assumption that the SyR motor gives more torque and then more power in continuous operation at rated windings temperature. However, the IM maintains a certain advantage in terms of flux-weakening capability that means a larger constant-power speed range.