High Torque/Ampere Direct Torque Control of Switched Reluctance Motor Drives

Direct flux and torque (DFTC) scheme is introduced for switched reluctance motors (SRMs) to minimize the inherent output torque ripples. In DTFC voltage vectors are chosen in such a way that the stator flux is kept constant, making it very sensitive to working condition. However, in SRM phases are independently excited, resulting in a nonlinear flux trajectory. In this paper, a new direct torque control (DTC) scheme is proposed, where sector boundaries are redesigned, and alternative optimized voltage vectors are selected. The proposed control technique also makes stator flux less sensitive to the working condition. This allows the phase to de-energize faster than the conventional DFTC, along with achieving high torque/ampere ratio with reduced ripples in torque. To show the effectiveness of the proposed DTC scheme over the conventional DTFC scheme simulation studies for the same operating conditions is carried out using Matlab/Simulink environment.