Power Electronics for Electromobility, Photovoltaics and Storage Systems

Thanks to our many years of experience in the development of customer-specific power electronics in the field of photovoltaic and storage systems, we identify the right specifications and system designs together with our customers and partners in terms of electrical parameters, mission profiles and climatic conditions. To implement compact and efficient power electronics, we use the latest semiconductor generations (silicon, silicon carbide and hybrids) and implement fast-switching designs with the appropriate circuit topologies. Various dimensioning tools assist us with the component selection and the subsequent realization of the schematics and layouts for the printed circuit boards. After the external production, our technicians and engineers assemble the electrical devices accordingly and carry out the commissioning of the converter stages. With the integration of customer-specific or specially developed cooling systems and housing, the prototypes or pre-series developments are electrically and thermally measured in our laboratories according to the recent device-specific standards.

In addition to the actual power electronics concept, the peripheral components of the assembly, connection and cooling technologies are increasingly coming to the fore of our research and development activities. Technological advances in these areas will significantly increase the power density and power-to-weight ratio in the future. With our extensive knowhow – from the optimization of the module layout, through double-pulse measurements to determine the switching losses or fiber-optic temperature measurements during semiconductor operation up to the optimal heat sink connection – we can support our customers and partners starting with the selection of the most suitable semiconductor module. To ensure that the resulting power loss can be dissipated in a targeted manner, we draw on internal expertise at Fraunhofer ISE so that we can implement optimal heat-sink concepts for the given application, e.g., with heat pipes or composite materials. During the development process, we focus on the cost-effectiveness of our power electronics design. If possible, we use standard printed circuit board technologies over a wide power range. The partial use of copper rails and the stacked structure of circuit boards help us to achieve very high-power densities.

The design and dimensioning of inductive charging systems for electromobility requires a wide range of expertise. From the constructive development of the inductive transmitters and their electromagnetic considerations to the design and simulation of the electrical resonance circuits and the associated circuit topologies, we are able to set up inductive energy transmission systems with a power of up to 40 kW, commission them and conduct appropriate laboratory and field tests.

In addition, we develop compact and highly efficient conductive charging infrastructure for the stationary sector with power output of up to 350 kW already today and even more in the future. Taking the device-specific standards into account, we implement innovative power electronic designs up to the pilot series.

To ensure that the components of electric vehicles are supplied appropriately with their respective current and voltage forms, multiple power converters are required. In developing the corresponding power electronics, the focus is on power density and power volume, combined with the economic efficiency.

In addition to the use of fast-switching semiconductors to reduce the volume of passive components, we identify optimal circuit topologies and security concepts for each application. We pay special attention to the necessary galvanic isolation, implementing it with the maximum efficiency. Furthermore, we are well-versed in the use of fluid cooling for power electronic systems.

Due to the transformation of our energy system, the existing rotating synchronous generators, which are largely responsible for the stability and formation of our power grid today, will be increasingly replaced by corresponding power electronic converters in the future. Innovative approaches to grid control and grid integration will help continue to ensure stability in a converter-dominated grid. In our department, we research and develop grid-supporting and grid-forming control algorithms for power electronic systems. A wide range of well-known development tools (Mathcad©, MATLAB/Simulink®, Octave, PLECS®, etc.) are available for developing the control technology. We also carry out the specific implementation and commissioning of the developed control technology on our various hardware-related development platforms as well as in our self-developed power electronics.

Every project begins with an idea and the subsequent concept development or a feasibility study. With our experts, we identify the circuit topologies that are suitable for the application, dimension the corresponding main components, and carry out a simulative evaluation of the system.

Likewise, the analysis, characterization and modification of existing power electronic converters and systems belong to our scope of activities. In particular, the characterization of charging infrastructure and drive converters can be performed in our unique laboratory infrastructure.

Through training courses, seminars, or lectures, we transfer our know-how in the fields of electric mobility and the grid integration of power electronics to interested professionals.