Analysis of Wind Ramping Product Formulations in a Ramp-constrained Power Grid

Abstract

Flexible ramping products are designed to compensate the variability and uncertainty of load and intermittent generation. Since their market implementation by the California Independent System Operator (CAISO) and Midcontinent System Operator (MISO), flexible ramping products have garnered much attention. However, it is still unclear how to best formulate wind power plants' participation in the ramping requirement. This paper investigates different wind ramping product formulations and increasing wind power penetration in the context of a security-constrained unit commitment (SCUC) model. We demonstrate that the ramping model that captures both the intra-and inter-temporal output ramp capability of individual wind power plants reflects the true ramp contribution of the wind fleet. With increasing wind penetration, wind generation curtailments can support the grid's ramping needs. In addition, we found that increased wind penetration has the potential of lowering ramping and production costs. Numerical case studies performed on the TAMU 2000bus synthetic network support the findings. , Flexible ramp-down capacity provided by unit at time interval , Flexible ramp-down capacity provided by wind power plant at time interval , Flexible ramp-up capacity provided by unit at time interval , Flexible ramp-up capacity provided by wind power plant at time interval System level load-shedding penalty at time , Generation output for unit at time interval ̅ , Maximum available generation output for unit in time interval , Generation output of unit in its block k at time , Total generation injection at bus in time interval , Wind power output for unit w at time ,