  Citation: Ibrahim, M.; Rassõlkin, A.; Vaimann, T.; Kallaste, A. Overview on Digital Twin for Autonomous Electrical Vehicles Propulsion Drive System. Sustainability 2022, 14, 601. https://doi.org/10.3390/ su14020601 Academic Editors: J. C. Hernandez and Thanikanti Sudhakar Babu Received: 25 November 2021 Accepted: 4 January 2022 Published: 6 January 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). sustainability Review Overview on Digital Twin for Autonomous Electrical Vehicles Propulsion Drive System Mahmoud Ibrahim * , Anton Rassõlkin , Toomas Vaimann and Ants Kallaste Department of Electrical Power Engineering and Mechatronics, Tallinn University of Technology, 19086 Tallinn, Estonia; anton.rassolkin@taltech.ee (A.R.); toomas.vaimann@taltech.ee (T.V.); ants.kallaste@taltech.ee (A.K.) * Correspondence: mahmoh@taltech.ee Abstract: The significant progress in the electric automotive industry brought a higher need for new technological innovations. Digital Twin (DT) is one of the hottest trends of the fourth industrial revolution. It allows representing physical assets under various operating conditions in a low-cost and zero-risk environment. DTs are used in many different fields from aerospace to healthcare. However, one of the perspective applications of such technology is the automotive industry. This paper presents an overview of the implementation of DT technology in electric vehicles (EV) propulsion drive systems. A general review of DT technology is supplemented with main applications analysis and comparison between different simulation technologies. Primary attention is given to the adaptation of DT technology for EV propulsion drive systems. Keywords: electric vehicle propulsion drive system; digital twin; hardware in the loop; real-time simulation 1. Introduction Considerable values have been brought to the entire industry over the last decades due to digital manufacturing. Through virtually represented factories, resources, work- forces, and skills, etc., digital manufacturing builds models and simulates product and process development. The remarkable progress in communication and information tech- nologies has advanced the development of manufacturing widely [1]. Computer-aided technologies, including Computer-Aided Design (CAD), Computer-Aided Engineering (CAE), Computer-Aided Manufacturing (CAM), Finite Element Analysis (FEA), Product Data Management (PDM), etc., are quickly developing and playing a vitally critical role in the modern industry [2,3]. Advanced data analytics and the Internet of Things (IoT) connectivity have increased the volume of data usable from manufacturing, healthcare, and smart city environments [4]. IoT environment, coupled with data analytics, provides an essential resource for predictive maintenance, fault detection, the future health of man- ufacturing processes, and smart city developments [5]. Digital Twin (DT) can overcome integration between IoT and data analytics through its ability to create connected physi- cal and virtual models. A DT environment enables high-speed and real-time simulation analysis accurately [6]. This review highlights DT as a trending technology in different applications and sectors as it is ongoingly discussed in the following sections. A deductive comparison between different simulation technologies over time is discussed in Section 1.1. Different existing and prospective applications of DT are presented in Section 1.2. In Section 1.3, varieties of DT software and platforms and their specific applications are discussed. DT for AEV propulsion drive system as the main review topic is extensively discussed in Section 2. A comparative analysis between Hardware in loop HIL and DT simulations for AEV propulsion drive systems is discussed in Sections 2.2 and 2.3, respectively. Figure 1 provides an illustrative diagram of the Introduction section’s content. Sustainability 2022, 14, 601. https://doi.org/10.3390/su14020601 https://www.mdpi.com/journal/sustainability