Fuel consumption minimisation of a microgrid

A cost optimisation scheme for a microgrid is presented. Prior to the optimisation of the microgrid itself, several power sharing schemes between two generators are compared. Then, the fuel minimisation of a small power system with a variety of power sources is discussed. The optimisation of a small power system has important differences with respect to a large system which falls into the traditional economic dispatch problem. Among the most important differences may be the presence of a local heat demand which adds another dimension to the problem. The small power system considered in this paper is a microgrid that consists of two reciprocating gas engines, a combined heat and power plant, a photovoltaic array and a wind generator. The optimisation is aimed at reducing the fuel consumption rate of the system, constrained to fulfil the local energy demand (both electrical and thermal) plus a certain minimum power reserve and penalised for any heat produced in excess of demand. The solution of the optimisation problem strongly supports the concept of having a dedicated communication infrastructure between the power sources.