Consequences of Flux Gap on Intriguing Features of Modular Stator Inset Permanent Magnet Consequent Pole Synchronous Machine

In this paper a novel Inset Permanent Magnet Consequent Pole Synchronous Machine (IPMCPSM) with H-type modular stator core for higher average torque ( $T_{a}$ ), torque density ( $T_{d}$ ), power density ( $P_{d}$ ) and efficiency ( $\eta$ ) with features of reduced torque ripple ratio ( $T_{r}$ ) and harmonics content in back-EMF ( ${\mathrm {EMF}}_{THD}$ ) are proposed. Detailed static analysis of the proposed IPMCPSM under variable flux gaps at all and alternate stator teeth is investigated. Performance analyses disclose that with variable flux gaps in proposed IPMCPSM, beside improved flux weakening capability due to flux focusing effects, electromagnetic performance is greatly improved. Additionally, due to physical isolation of the adjacent phase modules with modular topology, mutual flux influence is de-coupled that improve phase self-inductance to mitigate the short-circuited current under fault condition whereas mutual flux decoupling mitigates mutual inductance that ultimately improves overall machine fault-tolerant capability. Furthermore, effectiveness of the proposed IPMCPSM with H-type modular stator is elaborated with comparative study of conventional E-core and C-core topologies. Detailed comparative analysis reveals that proposed IPMCPSM suppresses ${EMF}_{THD}$ , improve $\eta $ by 18.9%, diminish $T_{r}$ up to 55% and boost $T_{a}$ and $P_{d}$ maximum up to 2.66, 2.59 times, respectively with enhanced flux focusing effects and fault tolerant capability.