The integration of renewable local energy generation in single households – turning the household into a “prosumer” – is an important way to support an ecological transition of the electric power system. However, due to the volatile and distributed nature of most renewable energy sources, the power system may face stability problems when integrating a large number of renewables. The paper at hand describes an approach to overcome these shortages in a two-fold manner: First, the effects of the installed renewables shall be limited locally to a group of households – a so-called “energy community”. To do so, all the participating households are using existing self-consumption optimization tools. However, when a household has excess energy which can not be consumed locally, this energy is shared among the other participating households by using a cluster storage device, thus enabling a community self-consumption before feeding into the low-voltage distribution grid. Second, the connected operator may request flexibility from the participating households. For that, additional loads or load sheds are triggered by the requesting grid operator, depending on the current situation in the grid. The households decide autonomously about the amount of granted flexibility, receiving respective financial incentives. This work introduces an energy management concept and a prototypical control infrastructure used for the aforementioned functionalities. In a number of simulations and field tests, the proposed approach was successfully evaluated. The article provides a comprehensive overview of the gained results and the conclusions derived from them.

Electric power systems are currently confronted with a fundamental paradigm change related to its planning and operation, mainly caused by the massive integration of renewables. To allow higher penetration of them within existing grid infrastructures, the “smart grid” makes more efficient use of existing resources by integrating appropriate information technologies. Utilising the benefits of such smart grids, it is necessary to develop new automation architectures and control strategies, as well as corresponding information and communication solutions. This makes it possible to effectively use and manage a large amount of dispersed generators and to utilise their “smart” capabilities. The scalability and openness of automation systems currently used by energy utilities have to be improved significantly for handling a high amount of distributed generators. This will be needed to meet the challenges of missing common and open interfaces, as well as the large number of different protocols. In the work at hand, these shortcomings have been tackled by a conceptual solution for open and interoperable information exchange and engineering of automation applications. The approach is characterised by remote controllable services, a generic communication concept, and a formal application modelling method for distributed energy resource components. Additionally, the specification of an access management scheme for distributed energy resources, taking into account different user roles in the smart grid, allowed for a fine-grained distinction of access rights for use cases and actors. As a concrete result of this work, a generic and open communication underlay for smart grid components was developed, providing a flexible and adaptable infrastructure and supporting future smart grid requirements and roll-out. A proof-of-concept validation of the remote controllable service concept based on this infrastructure has been conducted in appropriate laboratory environments to confirm the main benefits of this approach.

Virtualisation is a concept successfully applied to IT systems. In this work, we analyse how virtualisation approaches, such as edge computing, brokerage and software-defined networking, can be applied in the area of electricity grid management and control systems. Power system information and communications technology is currently subject to significant changes. Networked power grid components including renewable energy units, electric vehicles and heat pumps need to be integrated into grid management systems. We studied how virtualisation techniques can support system operators in increasing an energy and communication system’s dependability and situational awareness, and how manual (mostly field-level) configuration and engineering efforts can be reduced. Starting from a working hypothesis, three concrete use-cases were implemented and the performance enhancements were benchmarked to allow for well-informed answers to the questions above. We took a close look at application-protocol-independent redundancy, grid-based routing and online system integrity control. In these study cases, we found significant improvements could be achieved with virtualisation in terms of reduced engineering effort, better system management and simplification in high-level system architecture, since implementation details are hidden by the virtualisation approach.

Due to changed power consumption patterns, technological advance and deregulation, the appearance of the power grid in the low and medium voltage segment has changed. The spread of heating and cooling with electrical energy and an increase of electric vehicles as well as the broad rollout of photovoltaic systems has a major impact on the peak power demand of modern households and the volatility smart grids have to face. Thus, besides the load impact of the growing population of electric vehicles, modern households are not only consumers of electrical power, but also power producers, so called prosumers. The rising number of prosumers and the limitations of grid capacities lead to an increasingly distributed system of heterogeneous components, which have to be managed and operated with locality and scalability in mind. Virtualisation technologies, particularly known as state of the art in data centre computing, can lead to a paradigm shift needed to meet the growing demands of this evolution. A key issue here is to forward data to the correct data sinks, where data are required in order to keep the grid balanced. This routing process has to be able to react on grid changes in a timely manner, i.e., it must be based on the instantaneous state of the grid. In this paper, we propose a solution based on virtualising the communication infrastructure in the low and medium voltage grid. We evaluate two different approaches. The first approach is based on SDN; an ONOS SDN controller is used to change the behaviour of the communication infrastructure according to information provided by components of the power grid. The second approach uses Coaty and a Mosquitto MQTT broker to deliver messages to the desired endpoint, again based on information from the power grid.

The ever increasing integration of renewable energy resources into the electric energy system gives rise to new challenges on a large scale. New and extended information technology is necessary for controlling the corresponding power grids and their components. The need for advanced control functions and ancillary services provided by distributed energy resources is also increasing. As a response to this trend, this paper addresses the concept of an open and interoperable information technology solution specifically designed for the integration of renewable energy sources into smart grid systems. The concept addresses remote programmable and flexible functions used in resource constrained, distributed energy resources controllers. A generic communication infrastructure as well as an accompanying formal modeling and engineering method for distributed energy applications are introduced. The usage of the proposed concept is illustrated via a representative example.