Thermal analysis of switched reluctance motor with direct in-winding cooling system

Demand for compact high torque/power density electric machines necessitates the choice of an effective cooling system. The focus of this paper is to compare the steady-state thermal analysis of a naturally air-cooled conventional 8/6 SRM to the same motor with direct in-winding cooling system. The goal is to determine how much torque increase can be achieved by using direct cooling in the windings slots. The results show that the direct cooling of the winding guarantees lower temperature in the windings by 50% at a given operating point, although the winding slot volume is reduced by 25%. This means current density limit increases with direct winding cooling, hence improving the torque/power density of the machine

Temperature estimation of switched reluctance machines using thermal impulse response technique

Identifying the hot spots in an electrical machine is a critical step in the electromagnetic design process. Failure of this diagnosis can result in significant damages to the machine. However, a detailed thermal analysis of an electric machine can be extremely time consuming. Therefore, a new approach called Thermal Impulse Response (TIR) modelling is proposed to estimate the temperature of various parts in an electric machine. Use of TIR modelling will improve the simulation time significantly. Simulation and experimental results are carried to support the proposed method

Comprehensive Report on Design and Development of a 100-kW DSSRM

Switched reluctance machines (SRMs) are low cost and fault tolerant alternatives for traction applications. Due to their relatively low torque density and high torque ripple, these machines have not been used in commercialized electrified power trains yet. The double-stator magnetic configuration, where a segmental rotor shared between two stators, is proven to have superior torque density, lower acoustic noise, and torque pulsation. The double-stator SRM (DSSRM) has a high potential of being the next generation of traction motors since it combines the advantages of permanent magnet-free machines, such as low cost and independence from supply chain issues associated with rare metals, while providing high torque and power densities. This paper introduces the complete design process of a 100-kW DSSRM including electromagnetic, structural, thermal, and system level design. The performance of the developed DSSRM is verified with the experimental data. This paper presents overall study of DSSRM and describes merits of DSSRM drive system