Deadbeat direct torque and flux control of IPMSM drives using a minimum time ramp trajectory method at voltage and current limits

This paper presents the voltage- and current-limited operation of an interior permanent magnet synchronous machine (IPMSM) using deadbeat direct torque and flux control (DB-DTFC). A commanded air-gap torque and stator flux can be achieved by the end of each pulsewidth modulation (PWM) period using DB-DTFC. However, it may take several PWM periods to achieve a desired air-gap torque that is physically infeasible in one step due to voltage limits. In that case, the torque and flux command trajectories operating over multiple periods can be developed to achieve deadbeat torque and flux response for every PWM period. The torque and flux command trajectories can be developed in different shapes depending on desired objectives. In this paper, a minimum-time ramp trajectory method is proposed to achieve both simple real-time implementation and fast and stable transient dynamics of IPMSM drives. Simulation and experimental results for the minimum-time ramp trajectory method for an IPMSM drive are presented.