Vehicle Design

Traction inverters play a crucial role in the growing industry of electric vehicles. On the one hand, the traction inverter design is quite challenging and needs to pursue key design goals including high efficiency, high reliability, high power density, and low weight and cost. On the other hand, a modular and scalable design methodology to cover a wide range of vehicles is highly desirable. This article explores the optimal or near-optimal design configuration of the multilevel neutral-point-clamped legs of traction inverters for three use cases: an electric motorcycle, an electric passenger car, and an electric truck. The design is based on the use of an array of switching cells. The optimal configuration and operation of the switching cells are obtained through a weighted objective function in terms of efficiency, reliability, and simplicity. The design optimization results illustrate the modularity, scalability, and suitability of the used design approach, where a single module fits all applications, and the available degrees of freedom enable the adaptation of the design to the application and operating conditions, to maximize its efficiency and reliability.

The Horizon Europe HighScape project will explore the feasibility of a family of highly efficient power electronics (PE) components and systems for Battery Electric Vehicles (BEVs), including integrated traction inverters, onboard chargers (OBCs), DC-DC converters, and electric drives for auxiliaries and chassis actuators. 

In the work leading to this deliverable, the HighScape component providers and developers, focusing on the adoption of Wide Bandgap (WBG) based PE devices, have been generating the detailed simulation models of the respective components and systems (i.e., traction motor and traction inverter, OBCs, DC-DC converters, drives for Heating, Ventilation, and Air Conditioning (HVAC), and high voltage levelling suspension systems, and thermal systems for PE components/the whole vehicle), with a coverage of their parametrisation involving a wide range of BEV applications targeted in the project. The models enable model-based component and system design at the electrical, electronic, thermal and control levels. The components and systems models have been assembled into a vehicle simulation toolchain, for the rapid assessment of the implications of component design at the vehicle level, including considerations of thermal aspects. Due to the associated computational effort, the component models have been converted into surrogate models, such as Functional Mock-up Units (FMU) before their inclusion in the BEV simulation model. The definition, benefits and limitations of such surrogate models are discussed in the document.