Dynamic Risk Assessment
The most common approach to risk assessment for power systems is based on the N-1 principle. Nevertheless, the economic rationale suggests its relaxation in cases where the consequences are relatively minor and exacerbation when they are large. To tackle those issues we investigate an alternative methodology that could provide, a more accurate and realistic risk assessment, as it relies on time-domain analysis. As a result, planning processes based on our methodology could make the power system more secure and cost-efficient at the same time.
This study proposes an alternative operational risk assessment methodology that is based on both probabilities and costs of possible contingencies. The inclusion of probabilistic techniques allows a more accurate inclusion of the weather conditions into operation planning and the utilization of dynamic simulations allows obtaining results of the costs related to contingencies or outages, which are significantly more accurate and realistic than in the case of steady-state analyses. Both techniques, probability estimation and cost calculation combined form the dynamic risk assessment, the research on which was granted by the AXA Research Fund.
The probabilistic upper and lower risk boundaries are introduced to quantify the risk underestimation. The ratio of those limits is used as an accuracy indicator, which – according to the desired level – may help the TSO to identify the required number of contingencies that have to be analysed to assess the risk. Once the dynamic risk assessment is obtained, the design of the remedial actions could be modified in order to reduce the risk value and hence – the operational cost.