This paper is about a modelling and an optimisation of an electromechanical drive system. The device consists of a DC source, a power converter, a linear actuator and its load. The aim of the system is to drive a load along a linear displacement. The two main objectives are to reduce the actuator volume and the copper losses, which are contrary objectives. Here, we present an analytical modelling of the system and afterwards an optimisation of the linear actuator main dimensions in order to carry out the previous objectives.