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This work presents an experimental study of a hybrid T-type converter using wide-bandgap (WBG) devices, combining the low switching losses of gallium nitride (GaN) with the high-voltage capability of silicon carbide (SiC). Furthermore, an adaptive level-shift algorithm is introduced, enabling operation in both two- and three-level modes, improving fault tolerance and current capability. Experimental validation demonstrates high efficiency, minimal EMI impact at high switching frequencies, and improved THD, confirming the converter as a robust solution for high-performance applications.

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.

Permanent magnet synchronous machines (PMSMs) are still the first choice for use in electric vehicles, due to their unparalleledefficiency and power density. However, they suffer from an inherently limited speed range. As field weakening or the addition of amechanical gearbox deteriorates the efficiency of the drive, it is suggested in this paper to equip the drive with reconfigurationswitches, giving rise to a so-called e-gear. The switches—which are implemented by means of mechanical relays—allow to change the winding connection of the electric machine from a series to a parallel connection and hence to double its efficient speed range.Simulations and experimental results on a 4-kW axial-flux PMSM confirm the feasibility of the concept and prove that the reconfiguration can be conducted in less than 35 ms.

This paper presents a fast and accurate state-space model for synchronous machines taking into consideration the machine geometry, material non-linearities and core losses. The model is first constructed by storing the solutions of multiple static finite element (FE) simulations into lookup-tables (LUTs) to express the stator flux linkages as functions of the state variables, i.e., the winding currents and the rotor position. Different approaches are discussed to include the core loss into the model. A novel approach is presented for constructing a pre-computed LUT for the core loss as a function of the state variables and their time derivatives so that the loss can be directly interpolated when time-stepping the state-space model. The Simulink implementation of the proposed core-loss model shows a good match with time-stepping FE results with a 120-fold speedup in computation. In addition, comparison against calorimetric loss measurements for a 150-kVA machine operating under both sinusoidal and pulse-width modulated voltage supplies is presented to validate the model accuracy.

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.

The 'fit for 55' package is a set of legislative proposals introduced by the European Union in July and December 2021 to achieve the European Climate Law objectives of climate neutrality by 2050 and a 55% reduction in net greenhouse gas (GHG) emissions by 2030, compared to 1990 levels. It includes 13 interlinked proposals to revise existing EU climate and energy laws and six new legislative proposals. The package covers various sectors, including transport, energy, and land use, and aims to accelerate emissions reductions through measures such as the EU emissions trading system (ETS), the Effort-sharing Regulation, and the Land Use, Land-Use Change, and Forestry (LULUCF) sector. Key initiatives include stricter CO2 emission standards for new cars, the inclusion of maritime and road transport in the EU ETS, and the promotion of renewable energy and energy efficiency.

Modern Smart Grids are complex systems incorporating physical components like distributed energy resources and storage, along with cyber components for advanced control, networking, and monitoring. This study proposes an integrated methodology for risk prioritization and failure mode classification into low, moderate and high-risk faults using Grey Relational Analysis (GRA) together with Failure Mode and Effects Analysis (FMEA) and Deep Learning algorithms. The results demonstrate that, especially in complex systems like Smart Microgrids, the proposed method more accurately captures the coupling relationships between failure modes compared to the conventional FMEA method.

Hairpin windings are often applied in propulsion motors of electrical vehicles. There are several reasons supporting the technology. In mass production, hairpin winding work can be effectively automated, rectangular conductors offer a high copper space factor, a relatively simple structure and improved thermal management capability. However, due to additional AC losses generated at higher operating speed, there is a risk of local hot spots within the stator slot region, which might lead to overheating risk and insulation damage. There is also a growing interest to produce higher and higher specific power machines. Therefore, a new cooling concept is proposed that further improves the thermal management of the hairpin winding and allows to increase the specific power of the machine. The proposed method is based on direct oil cooling (DOC) through the channel of the hollow conductor. Special inlets and outlets in each hairpin coil are arranged. Comparison of the proposed cooling arrangement with the traditional cooling of machine with hairpin winding is provided by applying finite element method (FEM).

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.

In this document it details the work carried out in the HEFT project with regards to the objective of improving SiC-based drive control to reduce powertrain losses and improve EV range. The following issues will be covered:
1. Online variable switching frequency control strategy to optimize drive operation and reduce inverter and motor losses.
2. Optimal flux operation point to increase motor efficiency.
3. Improved powertrain thermal management strategy.
 

All these control aspects will be used in both A+B segment motor and C+D+E segment motor, as control strategy is the same for both motors that will be designed in HEFT project (only some parameters’ tunning need to be modified). Therefore, as use case, A+B segment motor has been selected, because this motor has already been designed. However, some preliminary results regarding C+D+E segment motor are also shown in this deliverable (this motor is still under development) to show that the proposed control strategy is valid for any IPMSM.