© Mesago | Uwe Mühlhäußer
PCIM Europe
https://pcim.mesago.com/events/de.html
Hall 5, booth 300
PCIM Europe, the leading trade fair and conference for power electronics, will be held in Nuremberg from 11 - 13 May 2024.
Fraunhofer IZM will be presenting its entire range of services from in the realm of power electronics at PCIM – covering everything from system design and packaging technologies for power electronics up to reliability aspects and cooling concepts.
On-board chargers (OBC) are indispensable in modern EVs. Fraunhofer IZM is developing an innovative bidirectional 22 kW system based on planar inductors and transformers to minimize production costs. The OBC performs worldwide in 3 and 1-phase grids for a very wide input voltage range and can be toggled for 400 V and 800 V batteries. Thereby an efficiency of over 97 % is achieved in a volume of 3 liters.
As part of the European project "HiEFFICIENT," the use of novel and high-performance semiconductors, known as wide-bandgap semiconductors, is being investigated for the next generation of electric vehicles. The project aims to develop an efficient integrated charging unit for electric vehicles with a power of 22 kW.
For on-board chargers in electric vehicles, galvanic isolation between the power supply network and the vehicle battery is required. By using gallium nitride semiconductors (GaN), switching frequencies in the megahertz range can be achieved, allowing for a reduction in volume through smaller magnetic components. For galvanic isolation and voltage transfer, a Sine-Amplitude-Converter (SAC) is used, which has an LLC topology in terms of circuitry.
The conversion of automobiles from conventional combustion engines to electric drives represents an enormous challenge for the automotive industry. In addition to high efficiency and low weight, costs are of particular importance in high unit volumes.
In an on-board charger for electromobility, besides a DC-DC converter that provides galvanic isolation from the HV vehicle grid, there is a so-called power factor correction converter (PFC) used as the interface to the public supply grid. It ensures purely sinusoidal fundamental currents (50/60Hz) on the input side.
A particularly bulky and cost-intensive component here is the PFC inductor, which has to absorb the voltage difference between the voltage in the supply network (230V/50Hz) and the DC voltage in the DC link (800VDC) and at the same time carry the full load current (32A for 3-phase 22kW units).
Advantages / characteristics
General issues
Inverter issues
The existing microclimate in enclosures is an elementary key point in the investigation of defects that are attributed to moisture. Currently, there are hardly any reliable statements on the microclimatic conditions in enclosures.
In the “RoDosH“ project the local microclimate in packages and housing of power electronic applications was investigated to derive effective local loading conditions. The focus was on temperature, humidity and loading conditions. The microclimate that is created in the housing during the application cannot be directly taken from the global mission profile. The aim of the project was to determine the relevant influence factors for humidity that diffuses into power electronics housings.
Autonomous electric vehicles draw power from two sources: a high-voltage battery and, additionally, a conventional 12-volt battery that supplies the vehicle when idling or in high load situations while driving. Safety-critical systems such as brakes and steering can therefore be connected to two sources of power. But what happens when one of these has a fault – a short circuit, for example? In order to safeguard against total failure and thereby a potentially dangerous situation, researchers from the Fraunhofer Institute for Reliability and Microintegration IZM have joined with partners on the HiBord project to develop an electronic disconnect device that is able to isolate any such faults in vehicle electrical systems. This module has already been successfully tested in a BMW i3.
Fraunhofer IZM introduces a package alternative to commercially available PCB-based Power CSPs: a mold-embedded power die, addressing power electronics packages requirements as good thermal conduction to bottom and also to top; high thermal mass on top for Wide Band Gap short circuit capability and low production cost. Major difference to PCB-based single chip packages is the use of an isotropic isolating material.
Fraunhofer Institute for Reliability and Microintegration IZM