Enabling Convex Energy Bids for Flexible Ramp Product via Smart Local Automation

Electricity markets, for the purpose of dispatch, approximate non-linear generator dynamics by a constant ramp rate R MW/10 min. The scalar R enables generator serving entity (GSE) to submit convex energy bids. Given the high penetration of renewable energy resources in US utilities, particularly California and Mid-West Independent System Operators (ISO), hard-to-predict wind ramps within the operating hour necessitate frequent ramping of generators, also known as load-following. A generator’s non-linear energy conversion dynamics varies widely over the operating hour. Consequently, the assumption of a constant rate R is often violated under fast changing operating conditions. In this paper, we propose a smart local automation on a non-linear energy conversion model of a coal-fired steam turbine. The proposed controller enables an improved and a near-linear dynamic response, ensuring fulfillment of convex bids.