Impact of load variations on the operating PF of an FCSC converter applied to wave energy systems

Forced Commutated Controlled Series Capacitor (FCSC) converters have been proposed for stand-alone wave energy conversion buoys to increase the system's power transfer capacity by preventing power factor degradation. In this paper, the effects of load changes on the operating characteristics of an FCSC circuit employed in a stand-alone wave energy conversion system are investigated, including a discussion on the effects of the distortion and displacement factors. The circuit is modeled and the impact of load variation on converter behavior is reported. The investigation is based on the development of the state space analysis of the generator-set. Based on the state transition matrix of the system, a model was developed allowing an investigation of the performance of the FCSC converter over a wide range of load variations. Results show that the power factor is mainly dependent on the load resistance and less so on the value of load capacitance.