This paper presents a nonlinear power system stabilizer based on a pointwise min-norm control law and a third order state space mathematical model of the synchronous generator connected through transmission lines to the power system. Commonly, the mathematical model includes transient electromotive force as a state variable that cannot be measured. Therefore, the mathematical model is transformed in a form containing all measurable variables. Furthermore, the control law for the proposed stabilizer also considers voltage regulation. The proposed algorithm has been implemented in a digital control system and its performance experimentally verified on a 83 kVA synchronous generator connected to the power system. Experimental results referring to the change in voltage and mechanical power reference, for disconnection of the transmission line, three phase and two phase short circuit, and forced oscillations are presented and compared to a PSS2A stabilizer. The experimental results show better performance of the excitation system with the proposed stabilizer compared to the system with a conventional PI voltage controller and PSS2A stabilizer. Furthermore, the results show that the proposed stabilizer is robust to system changes in the case of small and large disturbances, as well as near the generator stability limit. (C) 2016 Elsevier B.V. All rights reserved.