In a specialist article in the magazine “ElektronikPraxis” Finepower and HARTU jointly explain the advantages of inductors made of iron powder alloys in the increasingly important charging technology of electric vehicles.
Larger batteries require more charging power – in the same space
Reiner Nowitzki, head of the Finepower development team, highlights the trends in battery technology and the following requirements for chargers: With increasing demands on the range of electric cars, the capacity of the batteries must increase. Consequently, the performance of the chargers must be increased in order to fully “refuel” in a limited time window. Since there is always lack of space in the car, so the power density of the loader must increase significantly to pack more “kilowatts” in the same volume.
Fortunately, new power semiconductors made of materials such as gallium nitride (GaN) or silicon carbide (SiC) today allow the use of other and better circuit topologies with reduced losses at higher switching frequencies. With simultaneous optimization of the system components, significantly higher power densities can be achieved than just a few years ago.
Iron powder alloys increase the power density of inductors
One of the core components of chargers is the storage choke of the PFC* stage. Accordingly, the potential for optimization with correct material selection and dimensioning of this inductance is correspondingly high. In order to increase the power density, both the rms value of the current and the switching frequency of the PFC stage must be increased. As explained by HARTU’s Christoph Kammenhuber, iron powder cores allow the best compromise between high current carrying capacity and low core losses. And with different alloys, e.g. MANIFLUX series from HARTU, the material properties of the cores can be perfectly adapted to the respective application.