This paper presents a 4 kW GaN-based galvanically isolated bidirectional DC/DC converter suitable for on-board auxiliary power supply systems, interconnecting the HV battery with the LV power system. To enable the trend towards higher levels of electrification, a second LV level of 48 V is introduced to supply the high-power consumers, relieving the 12 V grid on the one hand and/or avoiding using additional costly isolated converters connected to the HV batteries on the other. The built converter prototypes aim to ...

Magnetic devices are an important part of electronic converters. They can be used to control some properties of the converters. There are three different control methods using an auxiliary bias-winding. In the presented paper, the impact of the implementation of the auxiliary bias-winding was studied for mixed biasing. Seven different designs were investigated in small signal measurements and 3D-FEM-simulations. The results were proven by calculated results of equivalent diagram circuits, which have been developed. ...

Almost all power electronic converters require magnetic devices and some properties of the converters can be controlled with magnetics. New magnetic materials enable implementation of magnetic control of converters also in high switching frequency applications. The presented paper gives an overview about controllability of magnetic devices in theory and practice, simulation approaches and examples. The focus is on electrically controllable magnetic devices. This means that an additional control winding is wound on ...

The design and construction of a 500VA microinverter for photovoltaic applications is presented. The developed microinverter is capable of operating as a standalone AC voltage source for small loads or, alternatively, as a grid-parallel system. Possible applications are therefore small off-grid installations as well as installations where space constraints do not allow enough modules to be combined to use string inverters. The design of the microinverter is based on a two stage concept. Two alternative topologies for ...

Controllable inductors can be realized by introducing auxiliary windings into the device that partially saturate the core and allow variation of the inductance value. This can be used to achieve zero-voltage switching in a DC/DC converter over a wide load range while at the same time the weight of the inductor is reduced. In this paper the possible size and weight reduction and the influence on the efficiency is calculated and compared to other solutions. The results are verified in a prototype.

In the course of decarbonization, interconnected systems will have to be prepared for recurring situations during which they are fed by mostly inverter-based generation. Today, the stabilizing influence of the rotating masses directly coupled to the grid via synchronous generators on every frequency change is essential. The inherent immediate reaction of synchronous generators on voltage-angle changes and frequency variations is called instantaneous reserve. During dynamic situations such as load or generation changes ...

Im Zuge der Dekarbonisierung müssen Verbundsysteme auf wiederkehrende Situationen vorbereitet werden, während derer sie vor allem aus Wechselrichtern gespeist werden. Der stabilisierende Einfluss der durch Synchrongeneratoren direkt an das Netz gekoppelten Schwungmassen auf jede Frequenzveränderung ist heute unverzichtbar. Die inhärente Sofortreaktion von Synchronmaschinen auf Spannungswinkeländerungen und Frequenzbewegungen heißt Momentanreserve. Wenn sich Verbrauch oder Erzeugung dynamisch ändern, und besonders ...

This paper presents an Interleaved Buck Converter with Coupled Inductors as a DC-Bias Current Source for Controllable Magnetic Devices, the modular interleaved Buck system supplies a low-ripple current for the auxiliary DC-bias winding of a controllable inductor with different biasing winding disposition in relationship with the main operating flux of the inductor. A 4-phase interleaved Buck converter system was built and inductance measurements where made for different operating current values of the DC-bias and the ...