Normalised Voltage Instability Sensitivity Index A New Concept for Monitoring Voltage Stability in the Control Centre

The increasing penetration of power electronics interfaced generation causes among others a displacement of conventional generation. Conventional generation has an inherent voltage control capability and therefore, these capabilities at the disposal of Transmission System Operators are decreasing. A survey conducted by members of the MIGRATE consortium indeed shows that Transmission System Operators expect voltage stability to be of increased concern for securely operating the power system. It is therefore crucial that control room operators are able to efficiently monitor the voltage stability of their power system, as well as get insights on how changes in load or generation influences the voltage stability. In this work, a new concept for monitoring the voltage stability is proposed. This concept includes a new index, the Normalized Voltage Instability Sensitivity Index N-VISI, and is able to effectively illustrate the impact of generation and load developments on the voltage stability in operational timeframes. Especially the way how different penetration levels of power electronics interfaced generation influence the small disturbance voltage stability can be effectively addressed and visualised. Following the illustration of this new index, high-level guidelines for implementing the N-VISI in the control centre are provided.