A Review of Fixed Switching Frequency Current Control Techniques for Switched Reluctance Machines
Sumedh Dhale, Babak Nahid‐Mobarakeh, Ali Emadi
Abstract
By the virtue of its highly nonlinear magnetic characteristics, the Switched Reluctance Machine (SRM) poses a formidable challenge for digital current regulators operating at a fixed switching frequency. Very fast tracking performance demanded by highly dynamic reference current profiles often surpass the conventional limits on closed-loop bandwidth posed by finite sampling frequency. The non-linear nature of matched disturbance to be compensated by the controller appearing in the form of induced emf grows in significance as a function of operating speed while the varying nature of inductance profile stipulates a need for gain adaptation by the control law in order to maintain consistency in closed-loop dynamic response. In the view of these unique SRM characteristics, the paper presents a detailed theoretical analysis of the widely implemented current control techniques from literature and provides illustrations in the context of their implementation in a digital controller. The analysis presented in this paper can also serve as a foundation for more advanced versions of these control techniques as well as their combinations.