In this paper, a torque observation method based on linear parameter varying (LPV) approach is proposed for a wound rotor synchronous machine (WRSM) used in Electric Vehicle (EV) car (mainly used in Renault ZOE car). The machine is modelled with the consideration of model uncertainties in both the magnetic behavior and the machine resistance. The uncertainties of the magnetic behavior come mainly from the saturation effect of the inductance and are viewed as extra state variables of the system. Then by treating the derivatives of the magnetic uncertainties as states and disturbance variables, the machine model in state space form is formulated as an LPV system or an equivalent nonlinear time-dependent system. State observability and unknown input observability are studied. Finally, a robust LPV observer is designed to estimate the flux and eventually the torque of the machine. Both simulation and experimental results are illustrated on a benchmark of EV propulsion to show the effectiveness of the proposed observer.