Synthesis of advanced Switched Reluctance Machine topologies using microscopic force density analysis

Despite considerable progress in development of power electronic-based control of electromechanical energy converters (EMEC), relative small changes have been observed in the magnetic design of EMECs. A physically insightful understanding of mechanism of electromagnetic force generation can shed light into the process of design and control of EMECs, thereby creating new opportunities for EMEC performance enhancement. This paper starts with interpretation of Korteweg-Helmholtz force density formula and categorizes different factors which contribute to force generation in an EMEC. Switched reluctance machine (SRM) is chosen as the subject of present study; different approaches of improving force generation are identified and summarized as rules for topology synthesis. Through iterations of topology synthesis with aim at enhanced torque output, a novel hybrid airgap SRM topology is derived. Quantitative as well as qualitative analysis are conducted toward proposed topologies. Based on evaluations of steady state performance and variety of and performance indices, short flux path hybrid airgap SRM outperforms the other proposed topologies, hence proves the effectiveness of synthesis rules and process.