A Novel Model Predictive Direct Torque Control Method for Improving Steady-State Performance of the Synchronous Reluctance Motor

Abstract

Due to the particularity of the synchronous reluctance motor (SynRM) structure, a novel high-performance model predictive torque control (MPTC) method was proposed to reduce the high torque ripple and improve the performance and efficiency of the motor. First, the precise parameters of the SynRM reflecting the magnetic saturation characteristics were calculated using finite element analysis (FEA) data, and the torque and flux linkage maximum torque per ampere (MTPA) trajectory was derived by considering the saturation characteristics. Then, an MPTC model of a SynRM with duty cycle control was established, the MTPA trajectory stored in a look-up table was introduced into the control model, and the duration of the active voltage vector in one control cycle was calculated by evaluating the torque error. Finally, an experimental platform based on a SynRM prototype was built, and various performance comparison experiments were carried out for the proposed MPTC method. The experimental results show that the proposed method could reduce the torque ripple of the motor, the performance of the motor was significantly improved under various working conditions, and its correctness and effectiveness were verified.

Direct Model Predictive Control of Synchronous Reluctance Motor Drives

“…The maximum torque per ampere (MTPA) trajectory is evaluated offline [23] and stored as a 2D LUT, and it is represented in Fig. 4.…”

Automated QFT-Based PI Tuning for Speed Control of SynRM Drive with Analytical Selection of QFT Control Specifications

“…The transfer functions derived in Equations ( 5)-( 7) can be used for the PI controller tuning procedure, provided that there is no change in parametric variations in the above equations. However, due to the simultaneous effect of I d and I q with the cross-magnetization effect on L q and L d , variations occur in the magnitudes of the stator inductances [7]. Furthermore, the value of V d changes which in turn changes the value of K rτ for different operating points.…”

“…These advantages of SynRMs encourage their use in various small and medium-sized power applications, such as in fans, pumps, elevators, etc. However, due to their peculiar rotor structure and the high nonlinearity in rotor flux linkages caused by cross-magnetization currents, the speed control strategies of these SynRMs need to be more robust in nature [7].…”

“…However, the QFT procedure is yet to be implemented for SynRMs. The modeling of the motor used for control design in [7,20] is realized using experimental data. Thus, an analytical approach is needed to model the SynRMs.…”