Modeling MW-dependent ramp rate in the electricity market

Maintaining certain amount of reserves in the realtime electricity market is an important task to ensure the reliability of the grid operation. The traditional reserve designation method calculates the reserve capability of a resource based on its average ramp rate, which may misrepresent the true reserve capacity of the system. System reliability and economics could be affected by such misrepresentation under certain conditions. This paper proposes an efficient MW-dependent ramp rate reserve model that utilizes the ramp rate of a generator at its energy desired dispatch point (DDP) in calculating reserve, which accurately reflects the true reserve capacity of the system in real time. The proposed model is prototyped in ISO New England's real time market and the solution is demonstrated to be more accurate and efficient, thus improving the market operation's efficiency and reliability.