Optimal dispatching method based on actual ramp rates of power generation units for minimising load demand response time

Abstract

This study proposes a method to determine optimal load demand changes of power generation units, in order to complete a total load demand change for power grids in the minimum response time. The main feature is to exploit the information of actual ramp rates, which are the maximum changing speeds of generated powers in practice from power generation units. The proposed method is composed of two steps. First, actual ramp rates are estimated from historical data based on the piece-wise linear representations of generated powers. Second, optimal values of load demand changes are determined based on the solutions to an optimisation problem minimising the response time. A main challenge is on the uncertainties of estimated actual ramp rates and their effects on the response time. This challenge is resolved by exploiting Bayesian estimators to yield posterior probability distributions of the estimated actual ramp rates, from which the optimal response time and its confidence interval are obtained. Numerical examples are provided to support the proposed method and compare with existing methods.