0885-8993 (c) 2018 IEEE. Personal use is permitted, but republication/redistribution requires IEEE permission. See http://www.ieee.org/publications_standards/publications/rights/index.html for more information. This article has been accepted for publication in a future issue of this journal, but has not been fully edited. Content may change prior to final publication. Citation information: DOI 10.1109/TPEL.2018.2836866, IEEE Transactions on Power Electronics TPEL-Reg-2017-10-2026 1 Abstract—In this paper, a new deadbeat-direct current control (DB-DCC) method is proposed in which two adjacent active- voltage-vectors (AVVs) with one zero-voltage-vector (ZVV) are applied to an interior permanent-magnet synchronous motor in each control cycle. In this method, by considering the sign of the error between stator-current components and their corresponding reference values, two AVVs are selected. Then, the changes of stator-current components due to applying these AVVs are formulated. At the next step, duty-cycles of these AVVs are calculated such that deadbeat control of the stator-current components is achieved. To improve the efficiency of the proposed DB-DCC method, reference stator-current components are adjusted based on the principle of maximum-torque-per- ampere while the ZVV is selected such that the minimum switching transition occurs in each control cycle. Performance of the proposed method are assessed in MATLAB software and in practice where the results indicate that the proposed method reduces the stator-current total harmonic distortion in the steady-state and improves the dynamic response of the motor in the transient-state. Performance of the proposed DB-DCC method is compared with recent model predictive-current controllers (MPCCs) and deadbeat controllers where it is observed that by adopting the proposed method a superior performance is achieved. Index Terms—Deadbeat control, direct current control, duty- cycle control, permanent-magnet synchronous motor drives, total harmonic distortion. I. INTRODUCTION ODAY permanent-magnet synchronous motors (PMSMs) are receiving more attention in industry applications due to the merits of high torque inertia ratio, high efficiency, and high reliability [1-3]. Field-oriented control (FOC), also referred to vector control (VC), is the most famous method adopted to control PMSMs. By adopting FOC Manuscript received October 23, 2017; revised December 22, 2017 and February 20, 2018; accepted April 30, 2018. R. Sharifian Dastjerdi, M. A. Abbasian, and H. Saghafi are with the Department of Electronic Engineering, Faculty of Engineering, Isfahan branch, Islamic Azad University, Isfahan, Iran (e-mails: re.sharifian@khuisf.ac.ir, m.abbasian@khuisf.ac.ir, h.saghafi@khuisf.ac.ir). M. H. Vafaie was with University of Isfahan, Isfahan, Iran. He is now with the Department of Electrical and Biomedical Engineering, Ragheb Isfahani Higher Education Institute, Isfahan, Iran (e-mail: mh.vafaie@eng.ui.ac.ir). 1 Corresponding author at: Department of Electronic Engineering, Faculty of Engineering, Isfahan Branch, Islamic Azad University, Isfahan, Iran. Tel.: +983135002616; Fax: +983135354057. method, high performance control of d-axis and q-axis current components in an arbitrary reference frame becomes possible [4-5]. In conventional FOC method, proportional-integral (PI) controllers are used to regulate the motor currents; hence, dynamic response of the motor is restricted by the bandwidth of these current controllers. Furthermore, steady-state performance of FOC method is highly dependent to fine tuning of the PI controller gains [6]. In order to improve the performance of the motor, various control methods like model reference adaptive system (MRAS) [7], deadbeat (DB) control [8]-[14], finite control set- model predictive control (FCS-MPC) [15]-[17], etc., are proposed in recent decade where DB controllers are one of the most flexible control methods among them. As mentioned in [18], DB controllers have a very fast dynamic response; hence, these controllers are preferable for high performance applications where obtaining a fast dynamic response is of essence. In DB controllers, the mathematical model of the motor is adopted to predict the future behavior of the controlled variables and then the control process is performed in a manner that the actual value of the controlled variables reaches their corresponding values at the end of the control cycle. In other words, control system forces the error to zero at the end of the control cycle. Various DB controllers are proposed in recent decades with the objective of improving the steady-state and transient-state performances of direct torque control (DTC) and direct current control (DCC) methods; e.g., in [19], a DB-direct torque and flux control (DB-DTFC) method is proposed in which the torque error and stator-flux error are forced to zero at the end of the control cycle. In this method, at first, motor is modeled in the rotor reference frame and then a set of two equations is constructed to find the optimal voltage vector. To avoid rotary coordinate transformation and reduce the computational complexity of DB controller proposed in [19], an advanced DB-DTFC is proposed in [20] where DB control of stator-flux and torque is realized in the stationary reference frame; therefore, no decoupling and no rotary coordinate transformation are required. In DB controllers, the stator-flux and torque can be controlled simultaneously in an independent manner; hence, various control objectives can be considered in these controllers [21]-[23]; e.g., in [23], a deadbeat direct power Performance Improvement of Permanent- Magnet Synchronous Motor Using a New Deadbeat-Direct Current Controller Reza Sharifian Dastjerdi, Mohammad Ali Abbasian 1 , Hadi Saghafi, and Mohammad Hossein Vafaie T