Power Electronics for Electromobility, Photovoltaics and Storage Systems

In the field of power electronics for electromobility, photovoltaic and storage systems, we combine our extensive know-how with a unique laboratory infrastructure. Within our research projects, we are continuously working on increasing the power density and power-to-weight ratio, and consequently the integration density of power electronic systems. In addition, we specialize in the development of customer-specific solutions of up to 350 kW for electromobility, photovoltaic and storage systems. We develop efficient and multifunctional converters for all types of on and off-grid applications.

The increasing demand for sustainable, efficient, and emission-free mobility requires a wide range of power electronic systems. Highly efficient and high-power converters are necessary for mobile as well as the stationary applications, so that the driving range can be increased and charging times can be reduced. Our broad expertise and our state-of-the-art laboratory infrastructure enable us to develop highly efficient and compact power electronic systems right up to pre-series. We work together with original equipment manufacturers (OEMs), their suppliers, and manufacturers of charging infrastructure to realize innovative and individual solutions for power electronic systems.

Our R&D-Services in the field of »Power Electronics for Electromobility, Photovoltaics and Storage Systems« include:

Compact, Efficient and Customized Converter Systems

Kompakte, effiziente und kundenspezifische Umrichtersysteme
© Fraunhofer ISE
Battery inverter which, due to its modular design, can be used for industrial storage between 125 kW and 2000 kW.

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.


Innovative Assembly, Connections, and Cooling Concepts

Technology demonstrator of a 70 kVA PV inverter
© Fraunhofer ISE
Technology prototype of a 70 kVA PV inverter with optimized design and cooling technology.

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.

Inductive and Conductive High-power Charging Infrastructure

Prototype of an induction coil for wireless energy transfer.

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.

Highly Efficient and Compact Converters for Vehicle Integration

Fuel cell range extender with an output of 4 x 1.25 kW.

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.

Innovative Control Algorithms for Grid Integration of Power Electronics

© Fraunhofer ISE
Predictive control of switched 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.

Simulations and Studies on Power Electronic Converters for Electromobility, PV and Storage Systems

Simulation of the efficiency of a DC/DC converter with integrated control.

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.

More Information on this Research Topic

Research Project


High Power Inductive – Automated, Wireless Fast-Charging Technology for Autonomous Mobile Robots and Industrial Trucks

Research Project


Development of Vehicle-Integrated Photovoltaics for On-Board Charging of Electric Utility Vehicles



Hybrid Lithium-Ion Battery Storage Solution with 1500 V Systems Technology, Innovative Thermal Management and Optimizing Operation Management

Research Project


Reliable Power Converter for the Provision of Renewable Energy

R&D Infrastructure

Center for Power Electronics and Sustainable Grids