Open-Delta Flux-Modulating Consequent Pole Motors

This article proposes a new type of variable-flux permanent magnet (PM) motor, named “open-delta flux-modulating consequent pole motor” (OFCM). The armature winding (
$W_{a}$
) of the proposed OFCM is connected in an open delta, and it also serves as a field winding (
$W_{f}$
) by simultaneously supplying it with three-phase armature current and dc field current. The flux linkage of
$W_{a}$
can be adjusted by changing the field current. The flux-regulation capability and torque characteristics of the OFCM were investigated through finite element analysis (FEA) and experiments on a prototype machine. Using FEA, efficiency maps of the OFCM were also compared to those of a flux-modulating consequent pole motor (FCM) with
$W_{f}$
. The results show that the OFCM without
$W_{f}$
has significantly higher efficiency and maximum torque than the FCM.