Preliminary analysis of existing control systems for power supply infrastructure
The first task is dedicated to the definition of requirements for architectural patterns including both the power system and the control structures to be studied. The identification of scenarios is mainly driven by requirements from emerging applications, even if known problems of existing applications may also provide relevant inputs. Therefore a preliminary analysis of the existing control systems, of the typology of data and the temporal evolution of the processes they implement is performed at the beginning, by exploiting published material and partners’ experience.
Current control systems are based on a combination of local and centralised (or hierarchical) control, being implemented on SCADA systems. The combination of sensors, evaluation unit and actuators, on top of a hierarchical communication architecture allow different control objectives to be reached, such as voltage and frequency control by management of the electrical loads (shedding) and generation units. Some control loops have long deadlines (compared to the communication latency), while others require reaction within several periods of the 50 Hz power cycle. In current situations, some local control algorithms require no communication, while the centralised approaches require several roundtrip transmissions; hence, they make use of dedicated (expensive) communication lines if the communication latency of the centralised approach is not sufficiently short (e.g. for SPS -special protection systems- and WAMS -wide area measurement systems-).
In this task several of these centralised and hierarchical control loops will be analysed as they are typically deployed in existing situations. This analysis will include type and size of data that is exchanged, hardware, software and communication technology that is used, control algorithms, timing information (deadlines, latency, jitter), as well as a preliminary analysis of the effects of failures in each of these components on the application (FMEA - failure mode and effect analysis). This analysis should provide sufficient information to allow the modelling of dependencies of the electric power system on the information infrastructure to be started in task 1.3.