Control Parameters Optimization of Accumulator in Hydraulic Power Take-Off System for Eccentric Rotating Wave Energy Converter

Round 1

Reviewer 1 Report

The use of English in the article is adequate. However, my main and great concern is that the PTO description lacks clarity. In this sense, the paper could greatly benefit from a more comprehensive, clear and detailed description of Fig 2.  This is fundamental because this WEC concept has evolved with very different kind of generators along the years.

Besides, there are some further smaller points that could be addressed: 

- The introduction states that the "controlability of DD is a challenge and an hydraulic PTO overcomes ..."

This sentence, as such, goes against all the development path of modern robotics. Authors may wish to reformulate it.

-The article presents a scaled model 1:5 . It is a bit confusing which tests do they take with this model because it is stated that they have one accumulator but that they check the PTO.

- Fig 3 lacks details such as the exact type of generator, motor, gear box, and the purpose of the tank.

-The type of control reminded me of that applied in Point absorbers with linear generators. Maybe you could compare with it

Maria-Arenas, A.; Garrido, A.J.; Rusu, E.; Garrido, I. Control Strategies Applied to Wave Energy Converters: State of the Art. Energies 2019, 12, 3115. https://doi.org/10.3390/en12163115

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

The presented paper deals with an interesting study on ERWEC systems. On my opinion some improvements  should be introduced in the paper.

First of all, the quality of the figures should be increased (especially figure 5), and in some parts of the text something seams missing (e.g. at pag. 8).

Secondly, did the authors consider to use an ERWEC system mathematical model to optimize control parameter? This should be useful to reduce experimental sets.

Thirdly, the authors should include in the paper some explanation of the optimization procedure with GA (for example the objective function and the weight for each parameter, etc.).

Fourthly, the optimal parameters, should be tested in different inputs conditions. Did the authors do these tests?

Author Response

Please see the attachment.

Author Response File: Author Response.pdf