Line start synchronous reluctance motor with improved power factor for agriculture electric pump applications

Abstract

Line start synchronous reluctance motor (LSRM) is more efficient than the existing induction motor (IM). However, the power factor is a major concern in LSRM. The power factor of the LSRM depends on the saliency ratio. To increase the saliency ratio, either d-axis inductance (Ld) has to be improved, or q-axis inductance (Lq) reduced. Here, q-axis inductance is decreased by making the minimal or negligible flux variation in the q-axis. Initially, the rotor geometry has been optimized employing an optimization algorithm. Then, finite element analysis is adopted to predict the capability of the designed rotors. Stress analysis has been carried out for both axial and radial rotor structures to verify the mechanical robustness. The fabrication steps such as folding, stacking and screwing, wire cut, die-casting and milling process of both the rotor structures are explained in detail. Further, both the machines are tested with the centrifugal pump. From the test results, it is observed that the proposed rotor structure provides a higher power factor.