Mandatory regulations are published worldwide for the efficiency of line-operated electric motors. Compact single-phase induction motors (SPIMs) will not be spared in terms of effectiveness and efficiency, as new restrictions are set to be implemented no later than July 2023. As a result, the efficiency of capacitor-run SPIMs will be required to exceed (now) normal values and meet the standards of the IE3 performance class. Less consideration has been given to the influence of rotors bar form on SPIM performance and starting capabilities. It is a key topic that has been investigated by a recent study concerning the rotor squirrel-cage layouts with eight distinct bar forms, published on MDPI academic container.
The study is entitled “Effect of Rotor Bars Shape on the Single-Phase Induction Motors Performance: An Analysis toward Their Efficiency Improvement”, Energies 2022, with authors Chasiotis, I.D., Karnavas, Y.L., Scuiller, F.
The already published research works investigated several design, control, and manufacturing aspects. Nevertheless, less attention has been devoted to the study of the rotor bar’s shape impact, both on the SPIMs’ efficiency and starting capability. This gap is filled in this work by examining rotor squirrel-cage configurations with eight different bar shapes for the case of a four-pole/1.0 HP capacitor-run SPIM. A sensitivity analysis, which involves the simultaneous variation of the bar’s cross-sectional area, run-capacitor value, and auxiliary to main winding turns ratio, is performed. The motor’s electromagnetic behavior is estimated through finite element analysis. Through the acquired results, useful directions toward the SPIMs’ efficiency enhancement are provided, while simultaneously conclusions—not found elsewhere—are drawn concerning performance quantities, such as the motor’s starting current, currents shift angle, particular losses and breakdown torque.
The stator and rotor core of the SPIM are composed of thin laminae of electrical metals. The squirrel-cage of the rotor is manufactured of a conducting alloy by die casting. Because of its inexpensive cost, aluminium alloy is more commonly used in the fabrication of tiny SPIMs, and it provides for greater freedom in the design of the bar.