Silicon carbide (SiC) power semiconductors are superior to traditional silicon devices due to their higher efficiency and performance, but face challenges related to temperature swings caused by very low thermal capacity, which limits their lifespan. To address this issue, this study proposes control methods to regulate the junction temperature of the SiC devices also referred to as Active Thermal Control (ATC). This approach reduces temperature swings, thereby extending the lifetime of SiC devices. The article examines the practical impact of thermal management implementation. Main goal is to present advantages from system perspective, that can be gained in terms of longer life expectancy by reducing thermal stresses. The benefits were evaluated with three different lifetime models using a high-resolution simulation with a small timestep, that allowed detailed observation of switching behavior and thermal transients at the transistor level. Across all tested models, even a basic temperature management algorithm, implemented without any hardware modifications, resulted in quantifiable improvements.

DC link capacitors in DC/AC inverters can be bulky and expensive. Reducing capacitor size can improve power density and reduce the cost of the inverter. The capacitor size depends on the voltage and current stress experienced by the capacitor in operation. Dimensioning the capacitor current stress for all loads can result in significant oversizing. An optimized dimensioning of the DC link capacitor current stress for a specific load, e.g., the traction machine, and load cycle, e.g., a drive cycle, is presented for a passenger electric vehicle and an electrified heavy-duty truck. The analysis considers two types of traction machines: a permanent magnet synchronous machine (PMSM) and an electrically excited synchronous machine (EESM). Four different DC link designs, two for each application, are evaluated in simulations by considering the capacitor lifetime. Simulation results show that a 25% reduction in capacitor size is possible without negatively affecting the lifetime using the proposed method.

In a 2-level inverter, the DC bus bar links the power module to the DC-link capacitors. During hard switching of the power semiconductor, the stray inductance of the bus bar generates voltage overshoots across the switch and the DC bus. Existing literature primarily investigates the impact of these overshoots on the inverter's electromagnetic emissions. This paper focuses on assessing the effect of voltage overshoots on inverter switching losses through a combination of Double Pulse Test (DPT) simulations, drive cycle simulations, and experimental voltage overshoot analysis. Two bus bar prototypes with a 26% difference in stray inductance were developed for a 2-level inverter. The switching losses of the semiconductor were evaluated over drive cycles, revealing a 0.94% increase in energy losses due to the higher bus bar inductance. In line with that, switch-level DPT results indicated an increase of 1.14%. This suggests that analyzing inverter switching losses through drive cycle simulations is important as voltage spike measurement which shows a considerable amount of switching energy loss. Further, the voltage overshoot analysis reveals a 12% reduction in voltage stress on the switch attributable to stray inductance both in simulation and experiment.

This paper presents a co-simulation approach for an electric vehicle which combines dynamic models of electric machine, inverter, gearbox in PLECS with high fidelity models of driver, autobody, wheel, road and environment in CarMaker. Lumped parameter thermal networks to model heat dissipation in the electric machine and the inverter are also included. The aim is to demonstrate versatility of the co-simulation method in analyzing effects of driver behaviors on thermal performance of electric machine and inverter. Co-simulation results using two simulation tools are compared to those obtained entirely using a single tool. It is observed that performing co-simulation using low fidelity vehicle model results in underestimation of vehicle speed. Further, the impacts of three different driver models on the temperatures of electric machine windings and semiconductor junctions are analyzed. Differences of 30% and 25% in the maximum temperature are observed respectively between an aggressive and a defensive driver.

There is an increasing trend in reducing rare-earth materials due to environmental and cost concerns. It affects design and manufacturing of Permanent Magnet Synchronous Machines (PMSM). Changes in parameters such as size and shape of the magnets will affect requirements as operating efficiency and maximum torque. In this paper, the design of a 250 kW PMSM for a commercial heavy-duty vehicle application is considered in order to evaluate effects of magnets thickness variation on performance and driving cycle efficiency. With this aim, an electromagnetic model is built using Finite Element Method (FEM) and efficiency map computations are carried out to investigate the effects of the magnet variation. System simulations are then implemented in MATLAB/PLECS to evaluate the driving cycle efficiency. Simulation results shown that the reduction of magnet thickness leads to significantly improved operating efficiency with reduction of maximum torque.

A new zero-sequence control technique is presented in this paper in order to eliminate the circulating current flowing in power hardware-in-the-loop test benches for electrical machine emulators. The machine emulator studied in this paper is made up of two three-phase inverters with an inductor connecting their ac-side. Both inverters share the same dc-link allowing circulating flow of the electric energy within this loop in order to emulate the operation of high power machine drives. Unfortunately, common-mode voltage is also freely developed within the loop and creates high circulating currents that act as a disturbance for the control of the inverters. Available control techniques have not managed to completely eliminate this current and common-mode filters are used additionally in order to solve the problem. The proposed zero-sequence control utilizes a modified version of the space vector modulation and reduces the circulating current amplitude up to 2.1% of the phase current, eliminating the need for hardware filters. Simulation results from Matlab/PLECS verify the effectiveness of the developed controller.

This paper presents the design of a high-performance liquid-cooled heatsink for three-phase automotive inverters that attains uniform thermal distribution at the surface of the three power modules. Power modules with SiC-MOSFETs are used in this study and a uniform thermal distribution on the heatsink guarantees equal thermal loading of the semiconductor devices. A comparative study of various cooling plate geometries is made and their effectiveness in meeting the design objectives of low sink-temperature and coolant pressure drop and the highest possible temperature uniformity along the surface of the plate is presented. Plates with straight and wavy fins are compared with designs accommodating rectangular pins and the advantages of each case is shown with the corresponding simulation results. Key design parameters of the cooling plate geometries are optimized with an iterative process, which is presented with selective simulation results of 3D Conjugate Heat Transfer computations for coolant flow rates up to 10 l/min. The final heatsink design accommodates multiple rectangular pins and attains temperature difference of less than 2oC among the three SiC power modules.