IEEE standards for oscillating machines to advance direct-drive wave energy generators

The objective of this paper is to present the need for IEEE standards for oscillating machines employed in wave energy generators. Due to the oscillating motion of ocean waves, the wave energy generator profiles are highly non-periodic and stochastic. Currently there are no IEEE or IEC standards for these types of oscillating machines, and thus critical questions remain unanswered such as the nameplate ratings and efficiencies that should be targeted for cost effective operation. Oscillating operation in an ocean environment is presented in the paper including real-world speed, torque, and output power testing data from an ocean wave energy generator. Related standards are discussed to illustrate that the duty types are not suitable to describe and represent the oscillating motion of wave energy generators. The paper concludes with an example utility-scale wave energy converter (WEC) design including the demanding cyclic operating conditions, and then presents required standards.