A scaled point absorber wave energy converter with advanced control system was tested at a large wave flume for obtaining datasets that will be used for designing the WEC power take-off (PTO). To help achieve the testing goal, an analytical model to describe the input and output behavior of the WEC system was developed. The analytical model consists of two parts: a hydro-mechanical part that describes the wave-body interaction of the WEC, and an electromechanical part that describes the WEC PTO dynamics. System identification analyses were used in conjunction with experimental datasets to derive model parameters. A set of regular and irregular wave cases were designed and selected for developing multiple power generation performance curves for three different tuning variables: spring stiffness, PTO damping and spring pretension force. The analyses of the performance curves for selecting optimal performance and cost balance are described in details.