Design of a Mechanical Power Circulation Test Rig for a Wind Turbine Gearbox
Round 1
Reviewer 1 Report
The authors propose, construct and test a corresponding a test rig for wind turbines. The test rig is to be used for 5.8 MW turbines. This is a rather large rated capacity and hence a powerful turbine. Such wind turbines are found among the largest land-based turbines or in off-shore wind turbines. The forces involved in such turbines are considerable and hence the test rig needs to be able to apply significant stresses. Hence, this seems not to be a straight forward endeavour.
The authors argue that among the 2 used classes of test rigs (electrical / mechanical) the electrical rigs suffer from high investment cost stemming from the required motors and inverters, while the cheaper mechanical rigs have predetermined levels of torque. Their test rig is a mechanical test rig implementation that allows for adjustable torques.
The paper is overall well-written and of solid quality. Numerous graphics give detailed insight into the construction of the test rigs and the appendices give an extensive description of the experimental parameters.
However, one key point seems to be missing from the exposition. I can not find any comments on the construction costs of neither the test rig, nor of the the competing electrical test rigs. Since the authors claim that the involved costs for comparable electrical rig is the main motivation of using their design, the economical viability needs to be demonstrated more clearly. I would consider this as a prerequisite for publication, since this is the main motivation for the set-up. Otherwise, the technical description seems very sound to me, although i am not a wind turbine engineer and can only broadly comment on their quality.
The interest to the community is hard to judge. The work is surely of some interest to a specialised community. Assesing how novel the paper is within that community is beyond my expertise. However, it is a strongly technical paper that is unlikely to be relevant to anyone else than a wind turbine test engineer. Overall, I think this paper merits publication, but I recommend to at least include one dedicated turbine engineer in the review process to make sure this is suffciently interesting to the specialist community.
Author Response
- Construction cost of test rig
: I have reviewed a number of papers related to the test rig. We haven't found any examples of rig costs in the related papers. This part was not mentioned in this paper and was described as follows.
< Comparison of test rig construction costs >
Unit : ￦ one hundred million won(in Korean won)
|
Electrical power circulation test rig |
Mechanical power circulation test rig |
|
|
Inverter* |
3.7 × 2(set) = 7.4 |
0.8 × 1(set) = 0.8 |
|
Motor* |
5.9 × 2(set) = 11.8 |
1.0 × 1(set) = 1.0 |
|
2 Auxiliary gearboxes ** |
- |
2.2 × 2(set) = 4.4 |
|
Torque-applying device** |
- |
2.6 × 1(set) = 2.6 |
|
Sub-total |
19.2 |
8.8 |
|
Other |
Same cost when constructing test rig |
|
* The basis for calculating the inverter and motor
- The electrical power circulation test rig is 5.8MW based on the rated capacity of the gearbox under test.
- The mechanical power circulation test rig is based on 1MW based on the power consumption applied to the test rig during the tests described in chapter 4.1 of this paper.
(Consider the ratio based on the rated torque of the gearbox for wind power gearbox, 45.2kNm and the maximum torque of the test rig, 50.2kNm)
** The basis for calculating the 2 auxiliary gearboxes and the torque applying device is based on the cost of manufacturing this device.
-Mechanical power circulation test rig construction cost is reduced by 54.1% compared to electrical power circulation test rig.
Author Response File: 
Author Response.docx
Reviewer 2 Report
Congratulations on an interesting idea for a patent and article.
I agree with the authors that the first step in the study is to reducing failure rate is to investigate the performance of the WTGB (i.e., efficiency, noise, vibration, and durability). The reliability of a WTGB, measured in terms of performance and durability, can be evaluated through laboratory tests.
Your research on the development of mechanical power cycle tests tested for gearboxes up to 110 5.8 MW are very expensive for the industry. Further research directions can be developed on the basis of this platform. e.g. regarding the possibility of turbine drive in conditions of variable torque in a system with planetary gear and linear actuators.
I have little attention to the authors, the conclusions lack a description of directions for further work and research.
Author Response
Reviewers' comments:
Reviewer #2
- I have little attention to the authors, the conclusions lack a description of directions for further work and research.
: It is mentioned in the last two sentences of this paper.
Author Response File: Author Response.docx
