A Comparative Overview of Indirect Field Oriented Control (IFOC) and Deadbeat-Direct Torque and Flux Control (DB-DTFC) for AC Motor Drives

Indirect field oriented control(IFOC)has become a widely adopted solution for AC motor drives.Standard IFOC controls torque and rotor flux linkage via q-and d-axis current.Alternatively,deadbeat-direct torque and flux control(DB-DTFC)has emerged as a promising motor control strategy for the future,which manipulates Volt-sec.vector directly.Air-gap torque and stator flux linkage are decoupled and independently controlled over each switching period.Stator flux linkage is used as a separated degree-of-freedom to manipulate losses dynamically without compromising torque dynamics and torque ripple.In voltage-limited operations,direct selection of Volt-sec.allows DB-DTFC to fully utilize the dc bus voltage and produce fast torque.A single control law is used over a wide speed range.This paper aims to provide a comparative overview of the two motor controls regarding their sensitivity to parameters,current-and voltage-limited operation,loss manipulation,and torque ripple during signal injection.Based on the comparison,the ultimate objective is to demonstrate the opportunities and remaining challenges in DB-DTFC.