Emobility Project
Within the electronics development department, Krebs' engineers design and manufacture the hardware and software for the charging systems and define the interfaces for systems and components. This includes the construction of measurement systems, the test environment, and test vehicles for test scenarios to evaluate the software and hardware. In addition, a bidirectional DC-DC converter for the charging system of electric vehicles with the option of feeding energy back into the low-voltage grid was developed and manufactured.
Project partners
The integration of renewable energies, which are primarily installed in the distribution grid, presents new challenges for electrical grids. In particular, the connection of smaller photovoltaic systems at the low-voltage level can lead to feed-in situations into the higher-level grid level if the photovoltaic systems generate more electricity than is consumed in that grid section. Historically, the design of lines, transformers, switchgear, and protection systems in electrical grids was not planned for such load situations. This can lead to voltage instabilities, violations of the permissible voltage range, phase asymmetries, utilization or overloading of permissible equipment capacities, and even the necessary curtailment of local renewable feed-in (EinsMan - feed-in management according to Section 14 of the Renewable Energy Sources Act (EEG)). Just some of the resulting negative effects are an increase in grid losses, a reduction in voltage quality due to uncontrolled, volatile renewable feed-ins, a deterioration in supply security due to the increasing complexity of the supply structure, and the economic damage caused by the EinsMan (uncontrolled manipulation). In addition, the proportion of electric vehicles, which are primarily charged in the low-voltage grid, is expected to increase sharply in the coming years. These currently uncontrolled loads place an additional strain on the supply infrastructure. Therefore, intelligent charging management while maintaining constant grid capacities is essential. The controlled, intelligent charging of electric vehicles opens up further potential that can go far beyond the use of 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 the provision of 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 in order to be able to exploit this potential in the future. Technical enhancements to hardware and software are necessary, which are to be developed in the planned project. By developing the necessary products (e.g. bidirectional onboard charging system and communications unit), the project will make a direct contribution to the system integration of renewable energies, as the vehicle battery storage charging can be explicitly coordinated with the availability of renewable energies. Local feed-in-oriented utilization in electromobility will result in a significant improvement in energy efficiency and a reduction in CO2 emissions in the mobility sector, which represents a significant contribution to climate protection. The distribution and installation of grid-friendly charging electronics in electric vehicles and DC charging stations will lead to an improvement in the charging infrastructure at the location, a prerequisite for the widespread adoption of electric vehicles. The targeted technological developments are not aimed solely at private transport; rather, they provide the basis for scaled-up deployment in the electrification of local public transport, where charging power and battery capacity are significantly higher. Furthermore, the increasing use and rollout of electric vehicles charged with renewable electricity and offering new grid services will contribute to significantly reducing greenhouse gas emissions, particulate matter, and ambient noise, particularly road traffic noise in urban areas.
