Optimal operation of CCHP microgrids with multiple shiftable loads in different auxiliary heating source systems

Abstract

This paper studies the optimal operation of integrated system from the perspective of the demand side load shifting, aims at adapting to the unbalance between energy demand and supply in the combined cooling, heating and power (CCHP) microgrid. A shiftable electrical load model is proposed, which combined with the time-of-use (TOU) price strategy and environmental benefits of solar and wind power. Based on the TOU price strategy, the shiftable load models are established according to the user’s room temperature comfort demand and the allowable fluctuation range of the domestic hot water’s temperature, respectively. Then the optimization model is constructed, which takes into account factors such as economy and environment, and solved by a CPLEX solver. Finally, in order to deeply study the influence of TOU price on the system, the influences of heating/cooling and electrical load shift on the CCHP microgrids with different auxiliary heating sources are studied. The results show that the influence of Shiftable loads in the system using an electric boiler as an auxiliary heating source is significantly better than using a gas boiler; the proposed shiftable load models can reduce the operational cost by up to 17.02%; and have better effect than the existing one that only considers TOU.