Implementation issues and performance evaluation of deadbeat-direct torque and flux control drives

Despite many advances in deadbeat, direct torque and flux control (DB-DTFC) drives, practical implementation and evaluation challenges remain. Unlike field oriented control drives with current vector inner loops embedded, DB-DTFC drives utilize flux linkage estimates and inverse torque models to directly calculate Volt.-sec vectors, which yield significant difference in implementation and evaluation processes. Moreover, deadbeat controllers can only be formulated in the discrete time domain, which requires estimating states at the next sample instant and a clear events timing sequence between each sample instant. This paper is dedicated to presenting detailed implementation and evaluation approaches for DB-DTFC drives, with particular foci on processor events timing, discrete time current/flux observers tuning and evaluation, closed-loop DB-DTFC control law implementation, and feasible Volt-sec ranges to achieve deadbeat responses. Based on experimental results on induction machines and permanent magnet synchronous machines, this paper contributes to a systematic procedure for implementation of DB-DTFC.