Tobias Linnenberg

A market-based multi-agent-system for decentralized power and grid control

Due to an increasingly decentralized fashion of electricity generation from fluctuating, renewable energy sources, new control concepts have to be found to manage a multitude of distributed energy conversion plants and to minimize the amount of power reserve needed. The basic implementation of the ‘DEcentralized MArket Based POwer Control System’ (DEMAPOS) presented in this article applies a market-based, decentralized control of generators and consumers of electrical energy. The control as well as a power system simulation needed for system testing were designed, implemented and validated. The developed, agent-based control communicates via web services with the power system simulation which relies on real-world data. Results from various test runs demonstrate the huge potential of this control strategy.

Unified Energy Agents as a Base for the Systematic Development of Future Energy Grids

The need for the application of software agents and agent-technologies in highly diversified future energy grids is widely accepted today. Nevertheless, the very general concept of the agent paradigm still leads to misunderstandings and to the fact that agents are meant and utilized for very different tasks. Accordingly, the approaches that were presented in the Smart Gird area have major weaknesses in terms of comparability and a subsequently large-scale use. We claim that the introduction of a unified definition of an Energy Agent will help to create a coherent picture that can accelerate further discussions and the conversion of the energy supply. Considering a development cycle that consists of modeling and implementation, simulation, test-bed application and the deployment to real systems, we present here our definition of an Energy Agent that takes into account the law of conservation of energy. Further, we present a classification of Energy Agents according to their sophistication and integration level and outline the need for individual but standardized energetic option models.

Structure and classification of unified energy agents as a base for the systematic development of future energy grids

The ongoing conversion of our energy supply encounters a great interest of many different market players that were originally located in different industries. As a consequence, a vast amount of proprietary solutions for smart energy applications is flooding the market. This tends to be rather a problem than part of the solution for the systematic development of future energy grids. Here, the absence of necessary unifications and standards blocks further developments that would enable the creation of novel, market-driven and hybrid control solutions for various types of technical systems. To overcome these problems, we present in this article our notion and the definition of a unified autonomous software entity that we call Energy Agent. Based on the energy conservation law and a generalized energy option model, we claim that our Energy Agent approach has the capabilities to enable cross domain interactions between different types of energy systems and networks. Further we will outline a systematic development process for Energy Agents that considers implementation, simulation, test-bed application and a real on-site usage. By taking into account these development stages, we expect to concurrently develop a novel laboratory that enables to competitively test and validate new and hybrid control solutions before they are applied in real systems.

Analysis of potential instabilities in agent-based smart grid control systems

While the amount of electricity generated from small scale, distributed, renewable energy sources rises, the imminent risk of a system collapse induced by a tailspin of control elements is counteracted by a raise in control complexity. As decentralized controls are a viable solution for distributed and complex problems many systems envisioned to tackle tomorrows challenges of our electricity grid are agent based networks. The complexity of such systems makes them difficult to analyze and hard to handle. One of the major problems coming with decentralized control solutions are stability problems resulting in oscillations of the controlled systems. In this paper we discuss disturbances in smart grids resulting in system instabilities and present a possible solution for predicting and handling this type of problems.

Cross-Domain Energy Savings by Means of Unified Energy Agents

Abstract This chapter presents a novel approach to dynamic resource allocation in hybrid energy grid scenarios, called energy-agents . This concept allows the easy control of inter-domain energy exchanges, such as heat generation from electricity or gas, the production of gas from electricity, or vice versa, based on the first law of thermodynamics. In a first hardware and software implementation, we were able to showcase the functionality and usability of this approach, enabling the developers of smart grid solutions to use the same code throughout the entire development process. This reusability will help to keep down development time and costs. On top of this, we were able to realize energy and cost savings by dynamically allocating the energy sources, as required by the consumer processes.

Energiesysteme und das Paradigma des Agenten

Das Paradigma des Agenten findet zunehmend Anwendung in hochdynamischen und komplexen Bereichen, welche koordinierte oder koordinierende Prozesse erfordern. In diesem Beitrag werden neue Anforderungen an die Systeme der Energieversorgung und des Netzbetriebes vorgestellt und diskutiert, inwieweit das Agenten-Paradigma diesen gerecht werden kann.

Einheitliches und durchgängiges Engineering von Steuerungslösungen für hybride Energiesysteme und -netze mittels Energie-Agenten

Zusammenfassung Im Rahmen des vom BMWi geförderten Projekts Agent.HyGrid werden vereinheitlichte Energie-Agenten als Steuerungslösung für hybride Energiesysteme und -netze entwickelt und auf ihre Anwendbarkeit hin untersucht. Hierbei werden sowohl vereinheitlichte Daten- und Verhaltensmodelle entwickelt als auch ein Referenz- und Entwicklungsprozess entworfen. Mit diesem durchgehenden Entwicklungsprozess soll die Anwendung der Energie-Agenten, angefangen von der Planungs- und Simulationsphase bis hin zum realen Einsatz im physischen Vor-Ort-System, ermöglicht werden. Als Energie-Agent wird dabei grundsätzlich ein autonomes, dezentral operierendes Software-System verstanden, das unabhängig von der Sparte bzw. vom Energieträger auf mehreren Ebenen eines Energie-Verteilnetzes eingesetzt werden kann. Durch die Kombination unterschiedlicher Energieträger sollen insbesondere volatile Energieerzeugungsanlagen, wie Windkraft- und Solaranlagen, besser ins Energienetz integriert werden. Die Herausforderungen des Projekts liegen vor allem in der vereinheitlichten Modellierung unterschiedlicher Energieträger und -umwandlungsanlagen sowie in der Überbrückung der Lücke zwischen Simulation und der realen Anwendung vor Ort. Dieser Artikel stellt die bisherigen Erkenntnisse in Hinblick auf die Anwendung des Entwicklungsprozesses und des einheitlichen Datenmodells dar.

Design, implementation and testing of multi- energy infrastructures the multi agent way in Agent.HyGrid

Due to a high penetration by renewables and a strong trend towards decentralization, future energy grids exhibit an increasingly emergent behavior. As a consequence new engineering approaches, based on decentralized decision making, have been proposed. The Agent.HyGrid project provides a framework for the design, development and testing of energy infrastructures. However, in contrast to other approaches it allows the designer to consider all kinds of energy, not only electrical power but also, e.g., gas or heat. It was shown in small-scale scenarios, that the developed software artifacts were reusable in on-site systems. This avoids the redundancy, which is otherwise created by re-implementing the software for different systems. By closing the gap between simulation environments, hybrid hard- and software test-beds and real on-site applications, the Agent.HyGrid project intends to demonstrate that such systematic and seamless software development processes and the according tool chain are already viable today.

Stability Analysis of an Agent-Based Smart Grid Control Marketplace

Abstract While coupling locally dispersed producers and consumers to large distributed networks comes with different socio-economic advantages as increase in production, higher market adaptability and higher resource efficiency, an immanent disadvantage is the accompanying raise in control complexity. Distributed agent-based control approaches are envisioned as a solution for managing distributed and complex production, supply, and infrastructure networks. Nevertheless they are difficult to be analyzed and hard to be handled. The major challenges coming with distributed control solutions may be found in the field of stability problems such as oscillatory network conditions potentially leading to network collapses. In this paper a general modeling and stability analysis approach for networked nodes is presented and applied on a marketplace of an agent-based smart grid system to distribute an energy demand between producers. Finally the analytical results are evaluated on a smart grid simulation.