Powertrain modularity

This report specifies the active electronic switches and resistive and reactive passive components, as well as converters' materials such as bus-bars and coolers that will be developed in the RHODaS project.

Based on system and component specifications, a selection matrix is developed and active and passive components to be used on the prototypes are selected, as well as their joining elements, connections and casing.

The report details the results related to the design, fabrication and validation of the compact power modules, including active switches, gate drivers and auxiliary electronics, at a laboratory level conducted as part of the RHODaS project. Thermal degradation and undesirable electrical effects are also studied and presented.

This document describes fault-tolerant control strategies for the SiC/GaN power converter and the eMotor of the RHODaS integrated motor drive (IMD). It outlines control levels within the proposed IMD, details fast response strategies for critical faults managed by the power converter control and defines fault-tolerant control to be implemented by cloud/edge computing for the IMD. The document also addresses potential faults in the power converter and electric motor, discussing feasible fault detection strategies.

This document provides a comprehensive report on the activities related to the experimental validation of lab-scale power converter prototypes. It includes an analysis of the current standards for power converter testing, drawing on publicly available sources and the expertise of RHODaS partners.

The document also proposes a detailed test plan for High Power Converters (HPC), which are based on Low Power Converter modules. This plan encompasses electrical tests for both Low Voltage (LV) and High Voltage (HV) parts, as well as environmental, mechanical, and safety tests. Additionally, the document reports on laboratory tests to verify basic parameters of Low Power Converters (LPC), such as efficiency, distortion, and Common Mode Voltage (CMV).

The analysis highlights the absence of comprehensive standards for inverter testing, necessitating the search for relevant documents from various testing fields. Due to the high voltage levels considered in the DC/AC converter, of at least 1000 VDC Bus, it is necessary the adaptation of research methodologies in cases where direct references are lacking. This process requires substantial knowledge and experience in test systems and application of standards.

The conclusions drawn from these activities are expected to support future design, optimization and recommendations, focusing on further improvements in power converters and the use of standards specifically adapted for them in automotive applications.

The study of multilevel dual-active-bridge (DAB) converters has garnered significant attention in recent years thanks to their advantages with respect to the conventional two-level (2L) DAB; namely, its greater performance and its capability to operate at higher voltage. The analysis of the converter high-frequency inductor current (𝑖LiL) is crucial, for instance, to compute its root mean square (RMS) value, required to estimate the conduction losses in the converter. The mathematical expression of 𝑖LiL is piecewise and multiple variations, i.e., modes, exist depending on the modulation parameter values. This increases the complexity of converter performance analytical study. Thus, a more practical and generalizable expression of 𝑖LiL current is desirable. This paper proposes novel compact analytic expressions for the instantaneous and RMS inductor current in the 2L-NL DAB converter, leveraging binary functions to define the piecewise intervals and to identify the mode as a function of the modulation parameter values. The proposed method paves the way for more simple and computationally efficient DAB performance optimization software tools that allow exploring any given converter structures and modulation strategies.