Ananalysis for net power characterization of a proton exchange membrane fuel cell (PEMFC) system is developed with Ballard 1.2-kW Nexa power module. A net power control (NPC) strategy based on the linear matrix inequality (LMI) approach is proposed to achieve optimal oxygen excess ratio (OER). The H-infinity suboptimal control problem is solved by LMI and the simulations are carried out under different conditional tests. The results verify that the proposed strategy can track the optimal OER trajectory and reduce the parasitic power as the running process of electrical vehicle is simulated. The comparisons testify that the NPC has better robust performance and less settling time in the presence of large disturbances and environmental noises. Therefore, the proposed strategy will provide a novel approach to increase the net power for the PEMFC system.