International Journal of Power Electronics and Drive Systems (IJPEDS) Vol. 15, No. 1, March 2024, pp. 19~26 ISSN: 2088-8694, DOI: 10.11591/ijpeds.v15.i1.pp19-26  19 Journal homepage: http://ijpeds.iaescore.com Improvised direct torque control of a permanent magnet synchronous motor Berhanu Deggefa Lemma 1 , Srinivasan Pradabane 2 , Tole Sutikno 3,4 1 Department of Electrical Engineering, Dire Dawa University, Dire Dawa, Ethiopia 2 Department of Electrical Engineering, National Institute of Technology Warangal, Telangana, India 3 Master Program of Electrical Engineering, Faculty of Industrial Technology, Universitas Ahmad Dahlan, Yogyakarta, Indonesia 4 Embedded Systems and Power Electronics Research Group, Yogyakarta, Indonesia Article Info ABSTRACT Article history: Received Sep 18, 2023 Revised Oct 5, 2023 Accepted Oct 23, 2023 Permanent magnet synchronous motor (PMSM) is widely used in different applications because of their different key operation features. But despite having important key features, PMSM suffers from torque ripple when simple control techniques like direct torque control (DTC) are employed. Several approaches have been raised by many researchers to lessen the ripple when DTC is used for controlling the PMSM drive. In this work, duty ratio-optimized DTC control, which has the same simplicity as conventional DTC (CDTC), and delay compensation for input signal prediction are proposed. In the proposed system, to determine the duty ratio, slope manipulation was made by considering the minimization of torque error and forcing the developed torque to be equal to the reference torque at the end of the span. An online slope determination approach was employed to compute the duty ratio. MATLAB 2021b is used for simulation purposes. The dynamics and steady-state performance of the proposed scheme were tested for both variable-load and variable-speed operations. In addition, the harmonic performance and ratio of harmonic power loss to total active power loss of the motor were evaluated. In general, the proposed scheme performs effectively in reducing steady-state ripple and harmonic. Keywords: Direct torque control Duty ratio PMSM Slope Switching time Torque ripple This is an open access article under the CC BY-SA license. Corresponding Author: Berhanu Deggefa Lemma Department of Electrical Engineering, Dire Dawa University Dire Dawa, Ethiopia Email: bezakiyya@gmail.com, berhanu.deggefa@ddu.edu.et 1. INTRODUCTION Permanent magnet synchronous motor (PMSM) has gained universal acceptance for any application due to its performance. Even though [1] and [2] suggested improving PMSM performance through design modification. In this work, flux performance and weight optimization were forwarded. The characteristic improvement is tested by changing the shape of the magnet and rotor. As PMSM is suitable for continuous duty operation, fault-tolerant inverter topologies and fault detection approaches were recommended to have a reliable system [3]–[6]. For PMSM operating at high temperatures and high loads, the effect of ripple on the motor and supply component is significant. According to [7], adding model parameters to the control algorithm and signal processing is recommended to reduce the thermal effect. The parameters of the motor are changing nonlinearly with temperature and load current. The nonlinear control system is proposed to include the nonlinear nature of a control system for PMSM in [8]. The nonlinearity due to magnetic saturation in the operation and performance of PMSM is considered in [9].