Peter Bretschneider

Energy management for distribution networks with storage systems — A hierarchical approach

This paper analyses the application of energy storage systems in distribution networks. Typical use cases are structured with respect to an optimal and integrated design of a energy management system. Based on a proposed architecture typical utilization aspects will be discussed and validated. The main emphasize is given to the adaptation of sophisticated optimization algorithms.

New approaches for smart grid requirements: Grid protection and optimization of distribution grid operation

This paper outlines new approaches in the fields of grid protection and optimization of distribution grid operation. The optimization aims to reduce grid losses by setting an optimal power factor at distributed energy resources at lower voltage levels. A Nonlinear programming approach is described modeling the optimization problem and causing high requirements on the mathematical formulation. Due to providing ancillary services by DER the grid protection has to be considered. Distributed generation causes changes in the direction and magnitude of short-circuit current and due to these misinterpretations of measurements at protection devices. An approach for adapting the protection parameters to the state of distributed in-feed is presented. Additionally an outlook on further developments on grid optimization and grid protection is given.

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.

Data Mining zur Analyse der Auswirkungen von Preissignalen auf Haushaltsstromkunden

Zusammenfassung Dieser Beitrag widmet sich der Analyse der Auswirkungen von Preissignalen auf das Verbrauchsverhalten von Haushaltsstromkunden. Er schlägt einen systematischen Auswerteprozess vor, der die Datenvorverarbeitung, verschiedene Aggregationsschritte, die Analyse mit Clusterverfahren (für preisbeeinflusste Typtage bei einzelnen oder aggregierten Haushalten) und die Analyse einzelner Abtastzeitpunkte umfasst. Dieser Auswerteprozess wird auf den Olympic Peninsula Project Datensatz angewendet.

A hierarchical management approach for electrical energy storages in distribution grids

In this paper an approach for optimal management of electrical energy storages in distribution grid with high share of renewable energies is presented. Within this approach a multi stage combination of a Storage Scheduling as a long term optimization and a Storage Dispatch as the short term consideration is applied. For this a reference distribution grid with realistic low voltage level structures is applied. The modeling of this reference grid is presented for several levels of the management approach. By means of currently assumed development data for energy generation from renewable fluctuating sources scenarios for the reference distribution grid are developed and the presented approach is investigated in numerical case studies. In conclusion, results of the model calculations are analyzed.

A contribution to the load forecast of price elastic consumption behaviour

By influencing the demand side by means of price signals (Demand Response) additional flexibility potential in electric supply systems can be provided. However, by influencing the demand side typical consumption patterns of previously unaffected consumers are changed. This will lead to increasing uncertainty in load forecasting. This paper deals with the forecast of load time series in consideration of price-based consumption influence. Additional requirements for load forecasting methods resulting from the price elastic consumption behaviour are analysed in this paper. Furthermore, the model residuals of established model approaches will be analysed to explain the disturbance characteristic caused by the price elasticity. Finally, the impact of the model residuals on the load forecast was investigated.

Optimal management of electrical energy storages for the integration of decentralized fluctuating generation in distribution grids

In this paper an approach for optimal management of electrical energy storages in distribution grids is presented. Thereby, the challenge for distribution grids caused by increasing share of decentralized generation with fluctuating feeding character is especially taken into consideration. A hierarchical approach for operational management of energy storages is presented. For this a reference distribution grid with realistic low voltage level structures is applied. The modeling of this reference grid is presented for the several levels of the management approach. By means of currently assumed development data for energy generation from renewable fluctuating sources scenarios for the reference distribution grid are developed and the presented approach is investigated in numerical case studies. In conclusion, the results of the model calculations are analyzed.

Technical and regulatory challenges for the integration of electric vehicles into the energy system

In this contribution the technical and regulatory challenges for the integration of electric vehicles into the energy system are identified. An investigation on the impact of electric vehicles for the medium voltage and subsequently for the low voltage distribution grid is realized. Therefore a benchmark distribution grid is designed based on existing benchmarks for medium voltage grids. As a result of the following simulation it is necessary to establish a charging management for electric vehicles for a secure integration. After the technical conditions the regulatory framework is considered to analyze whether a charging management operated by the grid operator can be established and how electric vehicles should be integrated into the current role model. Finally an optimization for a charging management operated by an energy retailer under consideration of grid parameters is analyzed.

Prognose für preisbeeinflusstes Verbrauchsverhalten

Zusammenfassung Durch die Beeinflussung des elektrischen Verbrauchs mittels Preiszeitreihen (Demand Response) können zusätzliche Flexibilitätspotentiale für die Energieversorgung erschlossen werden. Durch die Einführung von Demand Response ergeben sich jedoch neue Anforderungen an die Lastprognose. Dieser Beitrag befasst sich mit der Modellierung von preisbeeinflusstem Verbrauchsverhalten (PVV) und stellt einen neuen Prognoseansatz vor.

A Market System Operator as a new role to balance the distribution grid and to coordinate market and grid operations

An approach for an extended market grid operation is introduced in this paper. Therefore a Market System Operator as a new role in the electricity economy is defined and an extended ENTSO-e scheduling system is developed. Additionally a traffic light system for distribution grids is integrated. The special part of renewable energy sources with their specific character is taken into account. The aim is to retain a sustainable and reliable electricity supply system in Germany while and after the energy transition and to keep a free and liberalized electricity market as per specification from EU commission and German government. The approach helps to extend existing procedures without revising existing role models. This strengthens stakeholders and system operators as well as their communication.