Ariane Sutor

A Virtual Laboratory for Micro-Grid information and communication infrastructures

Testing smart grid information and communication (ICT) infrastructures is imperative to ensure that they meet industry requirements and standards and do not compromise the grid reliability. Within the micro-grid, this requires identifying and testing ICT infrastructures for communication between distributed energy resources, building, substations, etc. To evaluate various ICT infrastructures for micro-grid deployment, this work introduces the Virtual Micro-Grid Laboratory (VMGL) and provides a preliminary analysis of Long-Term Evolution (LTE) as a micro-grid communication infrastructure.

Variability management of safety and reliability models: an intermediate model towards systematic reuse of component fault trees

Reuse of fault trees helps in reducing costs and effort when conducting Fault Tree Analyses (FTAs) for a set of similar systems. Some approaches have been proposed for the systematic reuse of fault trees along with the development of a product line of systems. Nevertheless, these approaches are not longer effective when FTAs are performed after systems have been put into operation. This is mainly due to the lack of product line information required to make fault trees reusable. The model proposed in this paper is a step towards systematically reusing fault trees in the aforementioned context. It acts as an intermediate model between the specification of a system and its corresponding Component Fault Tree (CFT). In particular, it abstracts from the implementation details of a CFT, allowing the integration of variability inherent of product line systems as well as the one obtained from performing fault tree analyses incrementally over time. The model is part of a systematic reuse approach.

Smart Grid Information Exchange – Securing the Smart Grid from the Ground

The Smart Grid is based on information exchange between various stakeholders using open communication technologies to control the physical electric grid through the information grid. Protection against cyber attacks is essential to ensure a reliable operation of the Smart Grid. This challenge is addressed by various regulatory, standardization, and research activities. After giving an overview of the security demand of a Smart Grid, existing and appearing standardization activities are described. Moreover, an overview is given about potential roles in Smart Grid environments, which have been analyzed in the context of an EIT ICT Labs questionnaire.

Component fault tree analysis resolves complexity: dependability confirmation for a railway brake system

In 2006 Siemens Transportation systems had to obtain an operating license for the brake system of a newly developed train. Therefore a safety analysis for the brake system had to be performed to show that the probability of a failure of the brakes is sufficiently small, less than specified limits. The safety analysis was performed by Siemens Corporate Technology. The probability of a failure of the brake system was calculated using hierarchical fault tree analysis. The large number of different combinations of subsystems contributing to failure scenarios was managed by a specially developed program for automatic generation of combinatorial fault trees. The most important result was the proof of the quantitative safety targets of the brake system to the regulating body.

Application of a Reliability Model to Gas Turbine Design

The most important attribute of a product is quality. Quality influences the economics of an investment but also the economics of the manufacturer and can be a break point to the manufacturer’s prosperity. Consciously but often subconsciously quality is “just” expected and can therefore be seen as a straight measure of customer satisfaction — in the Kano-terminology quality is a “Must Have” parameter. In the power industry quality is generally being expressed and measured in RAMS (Reliability, Availability, Maintainability and Safety). For the development of new power generation equipment like gas turbines the targets are being laid out very early in the project. Since the development of gas turbine components can be a multi year undertaking it is paramount that the targets contain this element of future customer expectations. This ultimately drives the design team to challenge the technical boundaries — a gas turbine parameter that is satisfactory in today’s market environment might not be pleasing anymore in tomorrow’s changing environment. This is not only valid for the engines thermal performance but also for its reliability and availability. Siemens industrial gas turbines and components are therefore being developed with “Reliability Centered Design” in mind. This report describes the application of a predictive reliability engineering methodology to the development of new gas turbine components and how it influenced the design team’s decision making. The reliability analysis and prognosis is based on a predictive fault tree model with supporting Markov models to address consecutive failures or failure probabilities of stand by equipment. It has been validated with field data. While observation data retrieved from operational engines are being used for direct improvements of existing turbine designs the model based approach has its merits in supporting new designs by considering design or system alternatives. Further more it provides the sensitivities of the reliability of the gas turbine with respect to the components’ reliabilities. The model comprises the core engine but also the auxiliary systems within the package. This paper has been jointly prepared by the industrial gas turbine design team located in Lincoln (UK) and Finspang (Sweden) as well as Siemens reliability engineering team from Corporate Technology in Munich (Germany).Copyright