Improved Deadbeat Direct Torque Control of Interior Permanent Magnet Synchronous Motor with Flux Linkage Reference Correction

This paper adopts a deadbeat-direct torque control (DB-DTC) algorithm in interior permanent magnet synchronous motor (IPMSM), which is realized by combining the deadbeat predictive control algorithm with space vector pulse-width modulation (SVPWM). In order to achieve both the smooth torque and flux linkage responses in just one sample time period, control voltage vectors are derived and the limited solutions under SVPWM are classified. Then, to further improve the torque dynamic response when a large torque reference is added, the flux linkage reference is corrected by using maximum-torque-per-flux-linkage (MTPF), which is derived based on maximum-torque-per-current (MTPA). As an addition to the system, a cascade closed-loop flux linkage observer is then developed based on the current and voltage model of flux linkage. In the end, the entire system achieves a constant switching frequency and is verified to be accurate via simulations.