Improving electric power generation of a standalone wave energy converter via optimal electric load control

TL;DR

This paper develops a coupled model and optimization routine to enhance electric power generation of a wave energy converter by tuning the electric load based on sea state conditions, demonstrating significant improvements under irregular waves.

Contribution

It introduces a comprehensive coupled fluid-mechanical-electric model and an optimization method for electric load tuning, improving power output of wave energy converters in varying sea states.

Findings

Power generation significantly improved under irregular waves.

Optimal resistive load varies with sea state conditions.

The model accurately predicts electric response of the converter.

Abstract

This paper aims to investigate electric dynamics and improve electric power generation of an isolated wave energy converter that uses a linear permanent magnet generator as the power take-off system, excited by regular or irregular waves. This is of significant concern when considering actual operating conditions of an offshore wave energy converter, where the device will encounter different sea states and its electric load needs to be tuned on a sea-state-to-sea-state basis. To that end, a fully coupled fluid-mechanical-electric-magnetic-electronic mathematical model and an optimization routine are developed. This proposed time-domain wave-to-wire model is used to simulate the hydrodynamic and electric response of a wave energy converter connected to specific electric loads and also used in an optimization routine that searches optimal resistive load value for a wave energy converter under specific sea states. Sample results are presented for a point-absorber type wave energy converter, showing that the electric power generation of a device under irregular waves can be significantly improved. Keywords: wave energy converter, wave power system, wave-to-wire model, linear permanent magnet generator, electric load optimization.