Energy consumption has increased dramatically with the growth of the global economy, 1 resulting in increasing social concern over environmental matters. 2 The emergence and utilization of low-carbon and renewable energy is becoming the focus of energy development. In response to this situation, attention has been directed toward the oceans. 3,4 Wave energy is a major type of marine energy, with total reserves theoretically totaling approximately 3 billion kW. A third of this amount can be developed by technology, and the theoretical electric production is approximately 8000 TWh/y. 5 Different types of wave energy converters have been given considerable practical use to develop and utilize wave energy. The converters can be classified according to their structure, as oscillating-water column, pendulum, contraction wave channel, and raft types. 6

This study analyzes the hydrodynamic performance and application of a pitching float-type wave energy conversion device under complex sea conditions in the South China Sea. Potential flow theory and ANSYS-AQWA software are used to establish a method for analyzing hydrodynamic performance in both time and frequency domains, as well as the various factors that influence hydrodynamic performance. The frequency domain characteristics of the conversion device are explored, as well as the time-domain characteristics when exposed to regular and irregular waves. The results show that the frequency domain of hydrodynamic performance conforms to the requirements of an offshore mobile platform. A mooring point that is closer to the center of mass leads to improved stability of the conversion device. The angle arrangement of the anchor-chain mooring method fully conforms to safety requirements. When the wave direction is 45°, the conversion device is highly stressed and its movement is the most strenuous; however, the device can operate safely and stably under all working conditions. These results provide a significant reference for expanding the wave-energy capture range and the hydrodynamic performance of floating wave-energy conversion devices.