Testbed usage for architectural patterns
In order to deploy distributed control systems (to optimise power quality, cost, energy loss, …), a robust ICT infrastructure is required, partially based on fault-tolerant middleware that exploits the redundancy and diversity in heterogeneous communication networks. Given the dynamic nature of e.g. the Autonomous Electricity Networks application, this information infrastructure needs to support not only static configurations, but also modifications during the application’s execution (e.g. due to switching of generators and loads in the distributed generation application, the components that need to communicate will vary in time, and hence, the logical communication topology has to follow accordingly). This requires resource discovery and overlay networks, e.g. as deployed by peer-to-peer networks. Typically, such an overlay network consists of nodes that have knowledge of a subset of other nodes in the group with whom they communicate. Such network is self-organising into a graph in which nodes of equal functionality are close to each other. This can be achieved by comparing XML description files, describing the status of distributed generators. It illustrates that generators of the same type and generators within the same grid segment are close to each other in the logical network. The main properties of an overlay network are that it is scalable, self-organising and distributed: global properties are achieved through local interactions. Furthermore, they degrade gracefully in the advent of failures, restore automatically after repair and can cope with dynamic environments. It allows construction of a communication structure that requires little configuration, yet allows the implementation of distributed algorithms for the control and coordination of the nodes it contains, as well as for the aggregation of measured data. Furthermore, some phenomena require a control action within a few cycles, while others have seconds or even minutes of reaction time.
Critical attack processes will be simulated, and robust ICT infrastructures – and other architectural concepts from WP 4 – will be deployed and their effects on the control applications will be evaluated, also from a dependability perspective.