Martin Stötzer

Multi-criteria optimization of an energy storage system within a Virtual Power Plant architecture

This work aims to design the optimal energy storage capacity for Virtual Power Plant (VPP) architecture with a high degree of penetration of Renewable Energy Sources (RES). In order to achieve this target a multi-criteria analysis was performed. Economical issues as well as the reliability of the VPP are the main criteria taken into consideration. Sensitivity analyses were conducted to evaluating the robustness of the obtained results.

Power quality measurements of electric vehicles in the low voltage power grid

In this contribution power quality measurements of electric vehicles (EVs) will be presented. In the coming years EVs will become a more relevant asset in the power system. Due to infrastructural reasons and typical usage the EVs will be mainly connected to the low voltage power grid. That includes charging and - in case of vehicle-to-grid concepts — discharging processes with different power levels. The investigation of different kinds of EVs considers voltage drops, harmonics and power factors that allow for scaling up the impact on the power system. To interpret the results common standards and technical requirements are taken into account that describes the connection of loads as well as generators to the grid.

Concept and potential of electric vehicle fleet management for ancillary service provision

Security of supply is one of the main drivers of power system planning and operation. The upcoming integration of renewable generation, mainly in the low and medium voltage grid, will lead to the development of new system designs and new components. In addition to lowering the CO2 emissions in the transportation sector, electric vehicles (EV) will take part in system balancing in terms of directly influencing the charging and the discharging process to integrate renewable generation. Sufficient data from both the EV users and the infrastructure are necessary in order to forecast the time dependent potential that can be provided to the market. This paper considers a fleet management tool that generates the basic data for estimating the ancillary services potential of EVs in the German power system. Models, investigation methodology, computation results and results of a sensitivity analysis are shown and discussed in this paper, as well.

Smart grid in critical situations. Do we need some standards for this? A german perspective

The power system is changing rapidly due to the wide integration of renewable energy sources. In order to ensure a secure energy supply in the future power system (smart grid) the current laws, rules and standards concerning measures in critical system states to save or re-establish the system need to be examined. In this paper the authors provide a definition of critical states in the electric power system and describe measures to react in critical states or to prevent system instability based on current rules in Europe and Germany. The study aims to identify the demand for standardization in this area.

Demand side integration — A potential analysis for the German power system

One of the most important challenges todays transmission systems operators is the full integration of renewable energy sources into the grid. Already the current power system with the present amount of renewable generation sometimes reaches the limit of balancing stability as well as capacity of the power network. Due to changing weather conditions the load gradients today and those expected in the future require additional options to ensure high security of supply. Demand side integration (DSI) provides a high potential for power system balancing. In the case of high renewable generation the load can be shifted to these times. In this contribution the authors will show the methodology to estimate the DSI potential in the case of Germany and provide information about the present potential of DSI.

Communication interface requirements during critical situations in a Smart Grid

The power system is changing rapidly also due to the wide integration of renewable energy sources, mostly in the distribution grid. In order to ensure a secure energy supply today and especially in the future power system (Smart Grid) the current laws, rules and standards need to be examined concerning measures in critical system states to save or re-establish the system. In this paper the authors justify the standardization demand focusing on the expanded data exchange between TSO and DSO and propose a common communication concept according to IEC 61968/70.

Wandlung von Primärenergie in Nutzenergie

Zur Gewinnung der Nutzenergie, die entweder als Strom, Warme oder mechanische Energie abgesetzt wird, sind traditionell Verbrennungsprozesse unter Einsatz von Primarenergie wie Kohle, Ol, Gas und Kernenergie erforderlich. Der Umwandlungsprozess ist sehr aufwandig. Die vielseitigste verwendbare Nutzenergie ist der Strom. Der Umwandlungswirkungsgrad ist direkt mit dem CO2-Ausstos verbunden. Der Umwandlungswirkungsgrad ist zzt. nur mit maximal 50% zu veranschlagen, so dass alle zukunftigen Verbesserungen in der Kraftwerkstechnik eine Erhohung auf uber 50% anstreben, was durch eine kombinierte Nutzung mit der entstehenden thermischen Warme erreicht werden kann (Kraft-Warme-Kopplung). Der Verbesserung des Wirkungsgrades wirkt der notwendige, erhohte Aufwand fur die Rauchgasreinigung bis hin zur CO2Reduzierung entgegen. In den letzten Jahren hat die Bedeutung der erneuerbaren Energien am deutschen Energiemix durch die Energiewende deutlich zugenommen.

Business concept for distributed generation in the Swiss energy market

This paper contributes to the discussion about the future integration of Smart Grids in the existing energy supply system on a mostly economical and regulatory point of view. One of the main issues in this case is the increasing costs due to grid enhancements under regulated grid tariffs. On the one side a concept based on an integrative customer oriented approach is described and the new roles of the involved stakeholders in a decentralised network are discussed. On the other hand a simulation is presented to calculate the minimum energy costs based on a nonlinear constraint optimization in the context of a high amount of decentralised generation using different scenarios.