Abstract
This paper proposes a new scheme to use active flux on q-axis for
sensorless control of synchronous reluctance machines (SynRM).
Conventionally, “Active Flux” on d-axis is adopted to convert a
salient pole machine into a fictitious non-salient pole machine.
However, the injected d-axis flux can deteriorate high frequency
injection (HFI) sensorless control performance or even run the system
into unstable region at low speed. This paper demonstrates active flux
on q-axis can support back-EMF sensorless control at high speed and
improve low speed HFI performance substantially. A seamless transition
from HFI sensorless method to back-EMF voltage method is attained after
adopting the proposed active q flux. Experiment results are used to
validate the proposed method.