This paper presents an extended form of Feedback Linearisation Control (FBLC), which is tested in a non-ideal buck converter in Continuous-conduction Mode (CCM). The FBLC is often used in power electronics to control a non-linear system, due to its advantageous properties. The application of the error integrator shows better steady-state and transient properties, such as a decrease of inrush current. The linearised system has been controlled by the pole placement and the technique is illustrated through an example and simulated via Matlab. The results have been compared by using a classical PID controller, allowing the benefits of FBLC to be highlighted.