Reliability assessment of hydro dominant systems with diurnal energy management

Abstract

Hydro-electric generation is often energy limited due to insufficient river inflow during dry seasons. This can result in significant adverse impact on long term system adequacy. Most hydro plants are run-of-river types that have small head pond with limited storage capability to manage available energy to follow the demand variation. The opportunity for reliability enhancement of a hydro-dominant system through diurnal water management with the limited storage needs to be properly investigated. This paper presents analytical reliability models of head pond and power generation to recognize energy storage and the magnitude and time-shift of output power to match the diurnal load profile during energy limited periods of the year. The developed models are applied to the IEEE Reliability Test System that is modified to create a hydro dominant system. The impact on system reliability of diurnal energy management and the number plants involved in energy management are investigated in the study.