Modeling, Design, and Validation of Magnetic Hysteresis Motors

The use of hysteresis motors nowadays is limited to few niche-focused applications. Nevertheless, their intrinsic features make them ideal for next-generation high-speed machinery. Hysteresis motors are highly nonlinear and their behavior is heavily influenced by the initial magnetization state of the rotor active part. As such, the exploitation of hysteresis machine technology requires a reliable method to assess the torque capability, both numerically and experimentally. This paper proposes a finite-element model for the design of hysteresis motors. In this tool, rotor hysteresis is described through the vector generalization of the Jiles-Atherton model. For validation purposes, a prototype is defined based on a specific application. The torque of this prototype is experimentally characterized for different electrical loadings and rotor speeds. Subsequently, this output is measured after rotor magnetization at different levels. It is demonstrated that the initial condition of the rotor active part can be exploited in synchronous conditions to improve the machine output torque.

I. Introduction

Magnetic hysteresis machines have a simple structure with a conventional multiphase stator winding and a solid or laminated rotor made of semihard magnetic material (SHMM). In literature, hysteresis machines are regarded as self-starting motors and able to produce uniform torque from standstill to synchronous speed, accelerate, and synchronize high-inertia loads [1]. In addition, magnetic hysteresis can be exploited in controllable clutches and couplers [2].