In this work, Sliding-Mode Control (SMC) is employed in a cascade scheme in order to perform the maximum power point tracking (MPPT) of a permanent magnet synchronous generator (PMSG) based wind energy conversion system (WECS). In addition, SMC is used on the DC-AC power converter to achieve a suitable energy conversion and also the integration to a distribution network. Firstly, the WECS scheme is defined with a wind turbine generator (WTG) connected to an uncontrolled AC-DC rectifier, a controlled DC-DC chopper and a controlled DC-AC three-phase voltage source inverter. Then, the employed cascade scheme for each controlled power converter is detailed. SMC is achieved by using the space state representation of the converters. Finally, WECS performance is analyzed on different wind speeds and load profiles. The results are exposed remarking proper dynamic and steady-state responses.