Dispatch of wind-thermal power system containing heat storage units with fast ramping capabilities

Abstract

Wind energy is beneficial both economically and environmentally, while its utilization levels are still far from satisfactory and has plenty of room to be improved. One way to achieve this is to make use of the heat storage in some of the thermal generators to obtain fast ramping capabilities, so that they can catch up with the fluctuating and intermittent wind energy. Output characteristics of such thermal units are distinguished from conventional ones in that their ramping rates are dynamic and with memory, thus new models of system dispatch need to be established. In this paper, we present a mixed integer linear formulation with decisions of thermal unit heat usage for the dispatch of wind-thermal power systems containing heat storage units, and network security constraints of power balance and transmission limits are considered. Numerical tests are performed for a 3-bus system and the IEEE 30-bus system by using CPLEX, and results show that additional ramping capabilities from heat storage units lead to substantial improvements in wind power utilization.