Michael Agsten

Utilizing battery electric and plug-in hybrids for smart grid operation techniques

E-Mobility provides a wide potential for diversification of traffic sectors primary energy source. Until now petrol could be seen as the dominating one. The rollout of battery electric vehicles — plug-in-hybrids included — can be supplied by wind, solar, water, and coal and nuclear as the primary energy source. Obviously the rollout is strictly connected to the issue of grid capability to the additional electric load. First investigations show a concentration of charging in the noon and evening hours, which is coincident with common grid load. As a matter of fact there will be an overload on distribution grid devices and voltage dip, especially on low voltages cables, transformers and mid voltage cables. The rate of overload and voltage dip is hardly connected to the amount of supplied electric vehicles as well as to grid topology and galvanic distance between charge points. The following work deals in modeling and optimization basics of the expected electric load “EV” for simulation purposes. An especial architecture for managing EVs with special respect to the German liberalized market will be shown.

An ICT Architecture for Managed Charging of Electric Vehicles in Smart Grid Environments

Growing shortage of fossil resources and an increasing demand of individual mobility worldwide require technology alternatives to existing mobility solutions. Electric vehicles (EVs) as one possible solution have moved into the focus of research and development. To maximize the positive environmental effect of EVs, it is proposed to charge them with respect to the availability of renewable energies. As the number of EVs will grow in the near future, their impact on the power distribution grid is no longer neglectable. Related research shows that unmanaged charging of EVs could result in overload situations or voltage instabilities. To overcome this, methods are proposed to manage the charging process holistically. Herein EVs become substantial elements of intelligent power grids (Smart Grids). As of today, research in the area of Smart Grids focuses mainly on either energy aspects or communication aspects while neglecting the interoperability of energy and communication related aspects. In this paper, an insight into Information and Communication Technology (ICT) aspects with respect to Managed Charging of EVs in Smart Grid environments will be given. Based on the use case of Managed Charging, requirements will be analyzed, results will be derived, and ICT solutions will be proposed with a set of recommendations for Smart Grid architectures.

On the Optimization of the Load of Electric Vehicles

Abstract E-Mobility provides a wide potential for diversification of traffic sectors primary energy source. Until now petrol could be seen as the dominating one. The rollout of battery electric vehicles -plug-in-hybrids included – can be supplied by wind, solar, water, and coal and nuclear as the primary energy source. Mobility of tomorrow could be fully made in Germany. Obviously the rollout is strictly connected to the issue of grid capability to the additional electric load. First investigations show a concentration of charging in the noon and evening hours, which is coincident with common grid load. As a matter of fact there will be an overload on distribution grid devices, especially on low voltages cables, transformers and mid voltage cables. The rate of overload is hardly connected to the amount of supplied electric vehicles as well as to grid topology and galvanic distance between charge points. The following work deals in modelling and optimization of the expected electric load “EV”.

Einfluss Gesteuerten Ladens von Elektrofahrzeugen auf Verteilnetze bei volatiler Windeinspeisung

Zusammenfassung Der vorliegende Aufsatz fasst Erkenntnisse zum Gesteuerten Laden von Elektrofahrzeugen zusammen. Es werden zwei Verfahren gezeigt. Das Wind−2-Vehicle-Verfahren (W2V) ist Beispiel für die Nutzung Gesteuerten Ladens, um einer regenerativen Einspeisung folgenden Bedarf zu realisieren. Das Lokale Lastmanagement (LLM) ist Beispiel, um Informationen aus dem Verteilnetz zu nutzen, um die Ladeleistung von Elektrofahrzeugen zeitlich zu begrenzen. Abstract This work summarizes findings obtained from controlled charging of Electric Vehicles. Two approaches will be explained. The Wind−2-Vehicle method (W2V) is an example for using controlled EV charging in order to create a renewable supply following demand. The Local Load Management (LLM) method is an example for using information from distribution grids to limit the charging power of Electric Vehicles over time.

A continuous DC voltage control function for meshed HVDC grids, and the impact of the underlying future AC grid due to renewable in-feed

This paper discusses the development of a continuous high voltage direct current (HVDC) voltage control function for future meshed HVDC grids. Starting from a state-of-the-art discontinuous voltage droop control, which is used in point-to-point links, a continuously differentiable control function is developed. Using a mathematical description, the control function is transformed to meet the HVDC voltage control strategy for meshed HVDC grids. The control functions stability is discussed and its robustness is shown on an example. The example discusses and compares the current and future characteristics of the underlying AC transmission grid and the impact renewable in-feed has to the control function.

A pan-European-North African HVDC grid for bulk energy transmission — A model-based analysis

The usage of renewable energy is gaining importance due to national and international targets for reduction of CO2 emissions and consumption of fossil fuels and respective renewable energy deployment goals. Due to the volatile nature of renewable energy and regional potentials for generation in remote areas, there is a need for a better integration of generation and load centers in a common transmission infrastructure. This can be done by establishing a meshed HVDC overlay grid for bulk electricity transmission over long distances. Therefore, this paper describes the outlook for renewable energy deployment by 2050 in the North African region, as well as the potential to export renewable energy to Europe. It analyses the existing AC transmission grid infrastructure and explains why a meshed pan-European-North African HVDC overlay grid will solve the transmission requirements for the target year 2050.