Analysis of Power System Flexibility Considering Power System Ramp Rate

Driven by environmental issues and energy security, the global energy environment is evolving toward sustainability and carbon emissions reduction. The International Energy Agency's 2021 World Energy Outlook highlights the importance of clean energy innovation and increased adoption of renewable energy to achieve climate goals. As renewable energy sources become increasingly integrated with the existing grid, the variability of renewable energy poses challenges to grid stability. Existing flexibility indicators such as loss of load expectation, expected energy not served, and insufficient ramping resource expectation are not sufficient to evaluate short-term load changes and determine system flexibility from limited information. In this paper, a new approach is introduced to calculate the ramping performance probability of individual generators using data from those generators. The ramping performance probabilities of individual generators are represented by a probability density function, which is then convolved to produce a comprehensive power system flexibility index in the form of a cumulative distribution function. Data from the generators allows for the evaluation of the system's ability to respond to load fluctuations.