Multi-Objective Optimisation of an Active Distribution System using Normalised Normal Constraint Method

An increasing implementation of renewable sources and electric vehicles can be of help in reducing the total operational cost of a power system, affecting power system technical operation. To this end, a multi-objective optimisation method using Normalised Normal Constraint (NNC) is applied in this paper by which two competitive objectives are considered: Minimisation of Active Distribution System (ADS) operational cost and minimisation of ADS power losses. Meanwhile, the uncertain behaviour of wind, photovoltaic units, and arrival and departure time of electric vehicles are considered. The proposed model is a multi-objective problem which comprises two stochastic stages and is simulated under GAMS environment on a modified IEEE 18-bus test system. The results clearly represent the trade-off between economic and technical benefits of the considered ADS. Furthermore, the effect of electric vehicles charging and discharging tariffs on the operational cost of the system are shown.