Ralf Mosshammer

Rapid control prototyping platform for networked smart grid systems

With the progress of the smart grid development and the prototyping of active control solutions supporting grid operation in the presence of a large amount of distributed generators, a design methodology for networked smart grid systems is required. This paper proposes an approach for fast system simulation and emulation-supported prototyping. A distinct tool, the Simulation Message Bus, accompanies the development of distributed controllers for power distribution grids from concept to field application. With this, the idea of an integrated development tool chain as it is known e.g. in the semiconductor or car industry is brought to the energy domain.

Loose coupling architecture for co-simulation of heterogeneous components

Co-simulation of different domains is the method of choice if specialised tools exist for each domain and no monolithic solution is available. Motivated by the need for simulation and emulation of networked smart grid systems with interlinked controller, communication and power hardware components, this paper proposes a solution for loose coupling of heterogeneous components (i.e. continuous and time-triggered subsystems). The focus is on a lightweight message bus, allowing multiple simulators to exchange the same messages like in the real system. The architecture allows fast configuration and easy switching between emulated and real-world components. The solution is applied and verified in the context of a Smart Grid application. Photovoltaic inverters in a distribution grid are coordinated with a central onload tap change transformer in order to keep the grid voltages within the limits set by operation rules.

Java embedded storage for time series and meta data in Smart Grids

We present a Java-based embedded data store for edge-to-cloud storage optimized for Smart Grid time-series measurements. The key performance indicators expected of applications and operators of a Smart Grid monitoring and control system - frequent readouts, immutability, statistical indicators - are optimally supported. Furthermore, the data store is tailored for operation on platforms with limited storage and processing resources. We show that our implementation is superior to state of the art and off-the-shelf solutions in data retrieval time and needed storage size.

Grid watch dog: a stream reasoning approach for lightweight SCADA functionality in low-voltage grids

The advent of distributed energy resources in conjunction with recent developments in the context of smart embedded devices has fostered the increased integration of intelligent generators and prosumers into the energy system. As a consequence, previously passively operated grids have become highly dynamic environments, which require active monitoring and control. To allow for such monitoring and control, grid operators require lightweight SCADA-like functionality that can be flexibly adapted to dynamic grid contexts and is suitable for resource-constrained embedded systems. Grid Watch Dog enables system operators to create monitoring and control rules for low-voltage field devices on the fly, and to immediately deploy them in the field. The system combines a stream reasoner on field devices with an intuitive user interface for creating and managing rules. Grid Watch Dog has been implemented as a proof of concept in a smart grid testbed and we demonstrate its application in the context of monitoring a battery energy storage system.

Reactive Operation: A Framework for Event Driven Low Voltage Grid Operation

This proposal presents a prototypical realization of the “Reactive Operations” concept. The core feature of the “reactive operations” is to present an operator only with information in case this information is required by the operator to identify unsuitable system behavior (e.g. if faults occur) and to bundle the presented information event specific. This contrasts conventional supervisory control and data acquisition (SCADA) systems which constantly present an operator with specific system information.

Semantic annotation engine for smart grid applications

The advance of Smart Grid concepts towards lower-voltage layers of the electricity grid connects an enormous number of devices, many of them through legacy automation protocols, to back-end IT systems. With many of these devices giving little or no indication as to the semantics of their data, it is customary to manually engineer this information, which is cumbersome, costly and prone to errors. In this paper, we follow the web of things approach to introduce a smart aggregation layer device which allows for easy annotation of data with URIs tying into well-established ontologies, thus abstracting from technical addressing schemes. We present an annotation engine that can interlink actors of different sophistication levels in a light-weight messaging scheme, distributing data between operative algorithms, communication applications and operator interfaces. We present results of an ongoing field deployment of this approach in Austrian Smart Grids model regions.