Experimental and numerical investigation of resistive load impact on oscillating water column wave energy converter integrated with a parabolic breakwater

The performance of an oscillating water column wave energy converter with a parabolic breakwater was investigated by Ding et al. [1] and Mayon et al. [2] using numerical and experimental methods. Building on their work, this study examines the effects of resistive load on the Wave-to-Wire (WTW) conversion process. A time-domain numerical model for the WTW energy conversion process was developed, in which an energy capture chamber, an impulse turbine, a three-phase permanent magnet synchronous generator, and an adjustable resistive load were included. The model achieved bidirectional coupling between the turbine, generator, and resistive load, facilitating comprehensive simulation of the entire dynamic process. The turbine operating mode transitioned from high-torque, low-speed mode, to low-torque, high-speed mode with increasing resistive load. The resistive load influences the energy conversion process between the turbine and generator. The power duty cycle is introduced as a new variable for assessing the continuous operating capability of the generator. An increase in resistive load significantly enhances its performance. The bidirectional turbine improves the power generation capacity of the system compared with the unidirectional turbine, with a 43 % power increment when the resistive load is 5 Ω. This increase in power was positively correlated with the resistive load.