<p>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.</p>
Active Q Flux Concept for Sensorless Control of Synchronous Reluctance Machines