Economic dispatch in grid-connected and heat network-connected CHP microgrids with storage systems and responsive loads considering reliability and uncertainties

Abstract

Combined heat and power microgrids (CHP MGs) are energy efficient solutions for simultaneous supply of electric and thermal demand in a neighborhood and play a very important role in sustainable cities and societies MGs have energy management systems (EMSs) that aim to minimise their operation cost and include two modules; unit commitment module that determines commitment status of generating units and schedule of storage systems and dynamic economic load dispatch (DELD) module that determines the schedule of committed units and storage systems In this research, DELD in grid-connected and heat network-connected MGs with CHP units, boilers, microturbines, photovoltaic (PV) and wind units, electric and thermal storage systems, adjustable electric and thermal demand is formulated as a mixed-integer linear problem, while the reliability of the MG as well as uncertainties of PV and wind power, electric and thermal demand have been considered Monte Carlo Simulation and stochastic method is used to model the uncertainties In order to have a convex model in which the achievement of the global optimum is guaranteed, the non-convex feasible operating region (FOR) of CHP units is transformed into two convex feasible operating regions Moreover, effect of grid and heat network on MG operation and the sensitivity of MG operation cost to electricity and heat price are investigated The results show the effect of reliability and uncertainties on dispatch of resources and MG operation cost The results show that for the studied MG, with consideration of reliability, the operation cost increases by 14%, while.89, 10% of the cost is for Expected energy not supplied (EENS) cost and the remaining 90% is for other MG costs.