oa Power Grid Protection

Due to its inherent short-term dynamic, the power grid is a critical component of the energy system. When a dangerous event occurs in a section of the grid (i.e. a power line or a plant fails), the overall system is subject to the risk of a blackout. The time available to counteract the risk is very short (only a few milliseconds) and there are no tools to ensure the power to a number of selected critical facilities. A way to tackle the blackout risk and to implement a smart management of the remaining part of the grid is a distributed control system with preemptive commands. It's based on the idea, that in case of dangerous events, there will be definetly no time to inform the control center, to make a decision and to send the commands to the active components of the power grid where, finally, they will be executed. The idea consist in the implementation of an intelligent distributed control system that continuously controls the critical components of the power grid. It monitors the operational conditions and evaluates the ability of single components to work well and their probability of an outage. In parallel, the control system continuously imparts preemptive commands to eventually counteract the outages expected on a probabilistic base. The preemptive commands can be defined taking into account the sensitivity to specific outages by different network elements and of course, on the base of a priority rule that preserve the power for the strategic sites. In case of a dangerous event, the monitoring device directly sends messages to all the actuator devices, where the action will be performed only if a preemptive command was previously delivered. This means that the latency of the traditional control chain will be reduced to the latency of communications between monitoring and actuator devices. The first consequence of this policy is that an event, which is potentially the cause for a complete blackout will affect only a limited portion of the grid. The second consequence is , that the control system will choose the network elements that will be involved in the emergency procedure, preserving the strategic plants. The third consequence is that with this kind of control, the power grid goes from a N-1 stable status to another N-1 stable status. The system loses contributions of generation and load, but it keeps its stability and its standard operations.