Comparison between deterministic and probabilistic approaches in power system security assessment

In many countries today, the introduction of competitive supply and corresponding organizational separation of supply, transmission, and system operation has resulted in more highly stressed operating conditions, more vulnerable networks, and an increased need to identify the security level of the power system in both operating and planning scheme. There are two approaches used to assess the security level. One of them, the deterministic approach, is widely utilized in industry to perform security evaluation of power system operation by providing a basis for determining tradeoffs between security and economy. The other one, the probabilistic approach, can enhance this decision-making process by quantitatively assessing a number of uncertainties. In the thesis, we compare the deterministic approach to a probabilistic one via an overload and low voltage security assessment study to identify secure regions of operation or a secure facility planning for a local area within the IEEE Reliability Test System. The results of this comparison indicate that the probabilistic approach offers several inherent advantages relative to the deterministic approach