A theory of control in state space is applied to an electrotechnical process associating an asynchronous motor and a static convertor. The object is to realise current regulation for an induction machine. The process is inherently nonlinear and a classic regulator cannot ensure the same performances over all the operating range. A mathematical model of the process to be controlled is presented and a compensator determined. An observer and the desired regulation are chosen through the imposition of the system dynamics in a closed loop.