Robust Optimization Based Economic Dispatch for Managing System Ramp Requirement

The increasing penetration of renewable generation poses a challenge to the power system operator´s task of balancing demand with generation due to the increased inter-temporal variability and uncertainty from renewables. Recently major system operators have been testing approaches to managing inter-temporal ramping requirement. In this paper we propose a robust optimization based economic dispatch model for ensuring adequate system ramp capability. The proposed model is critically assessed with the ramp product which is currently under consideration by several system operators. We conduct theoretical assessment based on a proposed lack-of-ramp probability (LORP) index and numerical assessment using Monte Carlo simulations. It is shown that compared with the recently proposed industry model, the proposed robust formulation of ramp requirement yields more smoothed generation cost variation and is capable of ensuring lower lack of ramp probability.