Powertrain modularity

Gallium nitride (GaN) and silicon carbide (SiC) semiconductors can improve the power converters used in electric vehicles. These devices offer significant advantages due to their ability to operate at high switching frequencies while maintaining high efficiency. This paper presents a comprehensive comparison of modulation techniques for hybrid T-type converters that use SiC and GaN semiconductors. The analysis compares modified sinusoidal pulse-width modulation (M-SPWM), double-signal pulse-width modulation (DSPWM), and carrier-based pulse-width modulation (CB-PWM) techniques in terms of efficiency and DC bus balancing capabilities. The study examines the normalized voltage ripple and losses on the DC bus utilizing MATLAB/Simulink and PLECS. The simulation results indicate that DSPWM and CB-PWM hold promise as viable alternatives to the traditional M-SPWM technique for electric mobility applications, particularly when the power converter operates at high switching frequencies.

This deliverable provides updated specifications and requirements for the electrical, electronic, and thermal management subsystems of the RHODaS powertrain, building on those previously defined. It focuses on the design of a three-level, three-phase modular T-type converter based on SiC and GaN semiconductors, which must be compact to achieve the targeted gravimetric and volumetric power densities when mounted on top of the motor. The document details the converter’s dimensions, the integration of IMD components, and the semiconductor technologies under consideration.

Because commercially available GaN devices currently support only low voltages and currents, the deliverable proposes alternative strategies, such as using prototype GaN packs or parallelising multiple transistors, alongside a roadmap to address future design challenges. It also describes the supervision and monitoring strategies, including cloud-based functions, and defines the specifications for the thermal management system, with attention to environmental conditions and cooling requirements. The report concludes with a consolidated summary of the converter specifications, providing a reference for subsequent development and validation.

This paper presents a new gate-driving profile to mitigate the switching issues caused by high-speed operation of GaN transistors in on-off transitions. The concept consists of modifying the primary PWM signal applied to the GaN transistors to an appropriate voltage profile, which changes the gate-source voltage behaviour in the critical stage of the GaN transitions. The gate-driving concept is evaluated on LTspice, and the results show the reduction of ringing and overshoots when applying the proposal while maintaining tolerable power losses.

During the last 15 years, the automotive domain has been subject to several disruptive transformations, impacting the full supply chain and enabling the uptake of new services and solutions around road-based passenger mobility and freight transportation. Electrification, CCAM, and SDV are leading to a total redesigning of the vehicle and its components, and very equally to a rethinking of how to deliver value. While software is playing a key role for value creation, it strongly relies on innovative mechatronics platforms and smart powertrain and chassis components as foundation for the SDV of the future. Target of this paper is to introduce the results of the three complementary research projects HighScape, EM-TECH, and SmartCorners, with the focus to deliver consistent innovation along the three following pillars: (a) electrified powertrain and chassis components, (b) vehicle platform and highly integrated corner solutions, and (c) novel control algorithms making use of smart components.