Modeling, analysis, simulation and real-time hardware in-the-loop implementation of hybrid/electric vehicles’ powertrain

Abstract

This thesis investigates modeling, analysis and simulation of propulsion system in HEVs/EVs with particular emphasis on transient modeling. To achieve that, a novel complete simulation model on PSIM platform has been performed; proved worthy on two commercially existing cars in the market, namely Chevy Volt and Nissan Leaf. This was done using real data obtained from the Oak Ridge National Laboratory and the Environmental Protection Agency (EPA). Another milestone is that the simulation results have been validated experimentally in real-time through using Hardware in-the Loop (HIL) technology. In this thesis, the main focus is to develop a versatile generic approach based on transient analysis of HEVs/EVs propulsion powertrain. Moreover, evaluates the power train performance when incorporated with new futuristic innovative components. For example, a new proposed two-speed transmission system developed by inMotive corporation that can be applied to most of electrified vehicles. Further, wide band gap (WBG) devices such as GaN semiconductors and SiC devices have been integrated in the system, one at a time. A comparison study in terms of total power losses and efficiency calculations at different temperatures and switching frequencies due to using each of them has been accomplished. This approach is not only considering the system dynamics through controlling different state variables, but also implementing a daily real driving cycle to emulate exactly the same real driving environment. For a sound design, the developed model, which has low computational intensity, is utilized to determine the proper sizing and later the dynamic behavior of the main components such as battery, DC-DC converter, DC-AC converter and electrical motor. To prove the versatility of the developed model, it was tried on permanent magnet based cars (Chevy Volt and Nissan Leaf) and futuristic high performance induction motors (Audi eTron), a thorough investigation of the performance of three different topologies of induction motors; singly-fed induction motor (SFIM), doubly-fed induction motor (DFIM), and cascaded doubly-fed induction motor (CDFIM) has been conducted. This performance comparison is supported by a comprehensive finite element analysis and cost assessment to obtain the best candidate to be used in HEVs/EVs applications.