Willi Horenkamp

Charging optimization due to a fuzzy feedback controlled charging algorithm

A part of the worldwide CO2 Emission can be reduced by changing the mobility to electric vehicles and charge them with renewable energy. Renewable energy sources are often decentralized and local and can be a part of smart buildings. To maximize the efficiency a self-consumption of this energy is desirable. The main focus of this paper is to find a controlling algorithm for charging stations, which balance the renewable feed in and the charging power under respecting the EV-user habits. A fuzzy-based control algorithm shows good results in a simulation. To evaluate the fuzzy algorithm for controlling charging algorithm it is implemented on a charging algorithm development environment. After a measurement of an uncontrolled (UC) and a controlled (CC) charging cycle, a changed charging curve is evaluated. The founded data show also positive impact of the charging controller to the power grid.

Estimation of the costs due to renewable energies for a transmission system operator

By nature the generation from renewable energies sources is not performed on demand, but on offer. This yields the need of converting the energy to the actual demand. In Germany the execution of this process is obliged to the four transmission system operators. In this paper the occurring costs of the process of purchasing and transmitting renewable energies in Germany are analyzed for sample control areas. These costs include the expenses for additive required control power as well as the expenses caused by the special balancing group for renewable energies. During the operation of this balancing group accrue costs for balancing energy and as a result of trading transactions at electricity markets. Through this paper, the main question of the sensitivity of these costs from parameters in the observed control area is addressed.

Testing environment for Vehicle to Grid (V2G) applications for investigating a voltage stability support method

The rise of renewable energies on the one hand and the rise of electric cars on the other hand, requires expensive expansion projects of the low voltage network in many cases. With the help of alternative approaches, such as Vehicle to Grid (V2G) applications, the expansion actions can be circumvented. In this paper the problem of voltage stability is described in the low-voltage network. Some possible solutions for solving the problem are presented. A countermeasure in this case represents a DC fast charging station that supports the voltage stability with the help of a V2G application using a reactive power control. The problem is investigated by simulating a low voltage network of a rural area. Afterwards a testing and development environment is presented, which helps to verify the designed algorithms on prototypes and to verify conformity with technical regulations and standards. The technical implementation of the testing environment is described in particular.

Having a Cutting Point - Testing and Development Environment at TU Dortmund University

This paper presents the technology and testing platform for interoperable e-mobility, infrastructure and power grids at TU Dortmund University. That environment allows to emulate several power grid states and to analyse the behaviour of charging station and EV regarding to both electrical and ICT aspects. Using this technology platform we developed an alternative method for Residual Current Detection with DC components in electrical vehicle charging. Standard methods are not very well suited for these requirements, because they are very expensive and need a manual reset. The method which is presented in this paper detects the fault current by using an AC/DC summation current transformer in the electric vehicle. The fault current is announced by a fault state. A control unit in the charging station detects the fault state which is transmitted by using the control pilot. The cut-off is done by the already existing charging contactor which is included in the charging station. The fault state is transmitted by using the control pilot. The here presented protection method has a comparable security level to typically used protection devices. It allows cost savings by a factor up to 50. It can be used also for cut-off by detecting an isolation failure.

Ladeinfrastrukturen für die Netzintegration von Elektrofahrzeugen

Zusammenfassung Zukünftig werden neben Dezentralen Energieumwandlungsanlagen (DEA) vermehrt auch Elektrofahrzeuge an das Niederspannungsnetz angeschlossen. In Zusammenhang mit der Netzintegration wird auch die Bereitstellung von Systemdienstleistungen diskutiert. Damit verbunden ist die Forderung, dass beim Laden der Fahrzeuge als auch bei einer Rückspeisung elektrischer Energie die Versorgungsqualität, Versorgungszuverlässigkeit und Sicherheit des Netzes nicht beeinträchtigt wird. Ein intelligentes Lademanagement ist vor dem Hintergrund eines Smart Grid unabdingbar. Abstract Beside renewable energy sources also the integration of electric vehicles has to be considered for future low voltage grids. Related to this, the application of electric vehicles for ancillary services is discussed. In order to charge the vehicles or to feed-back electricity to the grid, it is necessary to assure the quality, reliability and security of the system. An intelligent load management system is mandatory to realize these smart grid applications.