With increasing penetration of renewable energy, uncertainty challenges ISOs to keep power balance in real-time. As ramping issues draw public... Show moreWith increasing penetration of renewable energy, uncertainty challenges ISOs to keep power balance in real-time. As ramping issues draw public attention, many ISOs have instituted flexible ramping products to ensure ramping reserve at generation side. However, not all the ramping reserves are deliverable when a transmission line is already congested. In the real-time market, if an uncertain load estimation is known at peak time t+10mins previously, SCUC/SCED is able to spare transmission reserve by changing the dispatch at time t with additional uncertain load constraints at t. To spare transmission reserve under uncertainty, this research proposes an uncertain load estimation to generate an estimated uncertain load and uncertainty constraints at t+10 in SCUC/SCED: with the help of a stochastic optimization model, uncertainties are quantified as a random actual load y and utilized in a modified stochastic model for undeliverable ramping reserve issues; once the optimal total system generation x is obtained, treated as an estimated uncertain load, uncertainty constraints are added at t+10mins in SCUC/SCED to obtain a secure dispatch at t. Therefore, transmission ramping reserve is ensured by a change in dispatch at t. Numerical results show that this design enhances the economy and scalability of power systems. In addition, scalability analysis proves it works for any scale of power systems with multiple local peak loads. M.S. in Electrical Engineering, December 2016 Show less