Direct Torque Control of A Segmented Switched Reluctance Motor for BSG in HEVs

This paper proposes a novel direct torque control (DTC) of a segmented-rotor switched reluctance motor (SSRM) for belt-driven starter/generator (BSG) in hybrid electric vehicles (HEVs). First, the initial design of this SSRM is given according to the specifications of BSG. The stator of the SSRM consists of two types of poles, i.e., exciting and auxiliary poles, and the rotor contains a series of discrete segments. Then, a novel nonlinear modeling method for DTC is presented. The torque-balanced method, Fourier model, and cubic spline interpolation method are employed to describe the nonlinear characteristics of the SSRM. Finally, simulation and experiments of DTC and current chopping control (CCC) methods are carried out and compared based on the modeling method. It is found that DTC can greatly reduce the torque ripple and the amplitude of flux linkage under DTC can be well controlled around the given value. Besides, the torque curves obtained from the DTC with and without the rotor clamping device basically agree well with each other.