A New Parallel Hybrid Excitation Machine: Permanent-Magnet/Variable-Reluctance Machine With Bidirectional Field-Regulating Capability

This paper presents a new topology of parallel hybrid excitation machine (PHEM), which integrates permanent-magnet synchronous motor (PMSM) and variable-reluctance machine, namely, doubly salient electromagnetic machine (DSEM), and provides a solution to better field-regulating capability. The configuration and the operation principle of the proposed PHEM are introduced. The combination criterion and design consideration are discussed. The performances of the two axial sections (PMSM and DSEM) are studied by 2-D finite-element analysis (FEA), respectively, to achieve reasonable integration. The field and voltage regulation capability of the PHEM is further investigated by 3-D FEA. A prototype PHEM is designed, manufactured, and tested. The measured results verify structural validity and finite-element predictions. The loss is predicted, and the measurement of short-circuit current illustrates the capacity of deexcitation at fault. The results confirm that the PHEM achieves effective power superposition of two different brushless machines. Bidirectional field-regulating capability facilitates a wide field regulating range of 6.5:1 under no load.