Emobility Project
Within electronics development, Krebs' engineers design and manufacture the hardware and software for charging systems and define the interfaces for systems and components. This includes the construction of measurement systems, test environments, and prototypes for test scenarios to evaluate the software and hardware. Furthermore, a bidirectional DC-DC converter for electric vehicle charging systems, capable of feeding energy back into the low-voltage grid, was developed and manufactured.
Project partners
The integration of renewable energy sources, primarily installed in the distribution network, presents new challenges for electrical grids. In particular, connecting smaller photovoltaic systems at the low-voltage level can lead to feed-in to the higher-level grid if the photovoltaic systems generate more electricity than is consumed in that section of the network. Historically, the design of lines, transformers, switchgear, and protective devices in electrical grids was not intended for such load conditions. This can result in voltage instabilities, violations of permissible voltage bands, phase imbalances, utilization or overload of permissible equipment capacities, and ultimately, the necessary curtailment of local renewable energy feed-in (feed-in management according to Section 14 of the Renewable Energy Sources Act (EEG)). Some of the resulting negative effects include increased grid losses, reduced voltage quality due to uncontrolled, volatile renewable energy generation, a deterioration in supply security due to the increasing complexity of the supply structure, and the economic damage caused by load management. Furthermore, a significant increase in the proportion of electric vehicles, primarily charged in the low-voltage grid, is expected in the coming years. These currently uncontrolled loads represent an additional burden on the supply infrastructure. Therefore, intelligent load management is essential while maintaining grid capacity. Controlled, intelligent charging of electric vehicles opens up further potential that extends far beyond simply using the vehicles as controlled loads. The location and control strategy of charging stations can contribute to counteracting voltage and grid quality problems and reducing grid losses. Modern power electronics are already capable of providing active reactive power for voltage support, phase-selective power control for phase balancing, or providing distortion reactive power to improve local voltage quality. The power electronics installed in electric vehicles or DC charging stations must be adapted and expanded accordingly to unlock this potential in the future. Technical enhancements to both hardware and software are necessary and will be developed within the planned project. By developing the necessary products (e.g., a bidirectional onboard charging system and communication unit), the project will make a direct contribution to the integration of renewable energies into the system, as the charging of vehicle batteries can be explicitly aligned with the availability of renewable energy. Local, grid-connected charging in electromobility will result in a significant improvement in energy efficiency and a reduction in CO2 emissions in the mobility sector, making a substantial contribution to climate protection. The widespread adoption and installation of grid-supportive charging electronics in electric vehicles and DC charging stations will improve the charging infrastructure at each location, a prerequisite for the widespread adoption of electric vehicles. The targeted technological developments are not solely aimed at private transport; rather, they provide the basis for scaled-up deployment in the electrification of public transport, where charging power and battery capacity are many times higher. Furthermore, the increasing use and rollout of electric vehicles charged with renewable electricity and offering new grid services will contribute to a significant reduction in greenhouse gas emissions, particulate matter, and environmental noise, particularly road traffic noise in urban areas.
