Assessment of the Harmonics Influence on the Power Consumption of an Electric Submersible Pump Installation

Round 1

Reviewer 1 Report

The paper needs a lot of improvement, mainly for the clarification of the contribution and its originality. 

the authors should take into account the following comments:

1. You have used the abbreviation ESP for “electric centrifugal pumps » which should be for “electric submersible pump”. Please check this!
2. Paragraph between lines 46 and 57 should be rewritten and revised in a precise manner. I think the authors know the impact of a frequency converter which is considered as a source of voltage harmonics and the harmonics mitigation in the network! There is a huge gap between the causes and the impact. We advise the authors to stay focusing on the used drive.
3. What do you mean by “reactive power losses”
4. The authors should clarify the difference of voltages (Uj) in equations (1) and (2) respectively.
5. The term “power of the source“ is very large. Please precise at each time the kind of power! Active, reactive, or apparent, without taking into account the harmonic terms.
6. Mainly the paper is focusing on the direct calculation of power losses in the studied system and the losses caused by harmonics. However, we could not find any novelty in this study, it is only a simple calculation, it can be related to a project but not a technical paper.
7. In equation (29), the harmonics start from 2, so why the authors have used the term High Harmonics (HH) can you explain this issue! It can be only harmonics!!! Why high harmonics!
8. This paper can be of technical value if the authors can clarify the novelty and the originally brought by their paper.
9. We could not find any new ideas in your paper all the formulations used in the calculation are taken from references!! what is new or original! this cannot be found in your paper.

Author Response

Thank you very much for your comments!

1. We've fixed this mistake

2. The paragraph was reformatted. The mention of harmonic filtering is given for the breadth of coverage of information: harmonics are not only measured and their influence calculated, but there are methods to deal with them.

3. Reactive power loss refers to the reactive power that is lost in equipment for generating magnetic fields. For example, in a transformer, reactive power losses describe losses due to magnetic flux leakage and magnetization losses.
4. Equation (2) has been modified. Losses are calculated through the current calculated according to equation (1), and not through power and voltage, as indicated earlier.
5. We've fixed these notices.

6, 8, 9. This paper is a generalization and addition to the research carried out within the project framework and it has great practical importance in calculating the steady-state modes of electric networks of oil fields. 

The main sources to which we refer in our paper are our publications in conference proceedings.

In this paper, for the first time, a block diagram of the OF ETC is proposed, which defines it as an interconnected set of electrical, electromechanical and hydromechanical subsystems with the emphasizing of controlled and observed parameters in each subsystem. The article contains an original scheme of interaction ETC ESP elements, an original approach to determining the parameters of the submersible motor equivalent circuit according to the catalog load characteristics.

A mathematical dependence of the submersible pump efficiency on the electrical and technological modes parameters has been developed (taking into account that the shape of the efficiency curve differs from a parabola, and the point of maximum flow, as a rule, is shifted from the center of the characteristic and does not always correspond to the nominal flow of the pump). The developed method for calculating power consumption makes it possible to take into account the mutual influence of equipment on power consumption within an oil field when changing the technological process parameters, which was not previously performed. Based on this technique, for the first time, an analysis of the mutual influence of ESP installations within the oil field was carried out and it was revealed that with changes in the parameters of the technological mode recorded at the enterprise, the mutual influence of equipment on the parameters of the electrical mode is insignificant and can be neglected. Also, an original result is the calculation of the ESP power consumption using the developed methodology, on the basis of which an estimate is made of the relative magnitude of losses in the equipment caused by the influence of harmonics.

7. In Russian-language literature, harmonics of the n-th multiplicity relative to the main one are designated by the term "higher harmonics". In general, the terms "harmonics" and "higher harmonics" are equivalent. The term has been corrected, the word "higher" has been deleted.

 

Reviewer 2 Report

1) It is desirable to extend the introduction part and add more recent literature review related to the topic in other chapters, too. For instance:

L. Gevorkov, A. Rassõlkin, A. Kallaste and T. Vaimann, "Simulation Study of a Centrifugal Pumping Plant's Power Consumption at Throttling and Speed Control," 2017 IEEE 58th International Scientific Conference on Power and Electrical Engineering of Riga Technical University (RTUCON), 2017, pp. 1-5

L. Gevorkov and V. Šmídl, "Simulation Model for Efficiency Estimation of Photovoltaic Water Pumping System," 2020 19th International Symposium INFOTEH-JAHORINA (INFOTEH), 2020, pp. 1-5

2) Please try to not leave empty space on pages: 4 and 8

3) In the description to equation (29) please indicate that rCL is a cable line resistance.

All together the paper is good and the topic is quite important.

Author Response

Thank you very much for your comments!

1. The introduction  was reformatted. Your cooments were rather valued!
2.  We've fixed this empty space.
3. We've fixed this fault

Reviewer 3 Report

The article was written well and interesting. A topic well suited to contemporary problems of electricity quality. Table 4, column I current, is probably a mistake. If there is no current, then there is no energy. 

Author Response

Thanks a lot for your comments!

There is no error in table 4. The values ​​"0" in columns 3, 6, 9 mean that the measurements did not reveal the current harmonic. The numbers of the corresponding harmonics for column 3 are presented in column 1, for column 6 - in column 4, for column 9 - in column 7.

Round 2

Reviewer 1 Report

No further comment

Author Response

Thank you very much for your comment

Reviewer 3 Report

In the first review, I slightly noticed that the work is poor. I am surprised at the attempt to save the topic from the students' work. Please see "Power quality" in academic textbooks. They have more interesting examples. 

Author Response

Thank you very much for taking the time to review the paper!

This paper is a generalization and addition to the research carried out within the project framework and it has great practical importance in calculating the steady-state modes of electric networks of oil fields.

In this paper, for the first time, a block diagram of the OF ETC is proposed, which defines it as an interconnected set of electrical, electromechanical and hydromechanical subsystems with the emphasizing of controlled and observed parameters in each subsystem.

The paper contains an original scheme of interaction ETC ESP elements, an original approach to determining the parameters of the submersible motor equivalent circuit according to the catalog load characteristics.

A mathematical dependence of the electric submersible pump (ESP) efficiency on the electrical and technological modes parameters has been developed (taking into account that the shape of the efficiency curve differs from a parabola, and the point of maximum flow, as a rule, is shifted from the center of the characteristic and does not always correspond to the nominal flow of the pump).

The developed method for calculating power consumption makes it possible to take into account the mutual influence of equipment on power consumption within an oil field when changing the technological process parameters, which was not previously performed. Based on this technique, for the first time, an analysis of the mutual influence of ESP installations within the oil field was carried out and it was revealed that with changes in the parameters of the technological mode recorded at the enterprise, the mutual influence of equipment on the parameters of the electrical mode is insignificant and can be neglected.

The final research stage is the assessment of the relative value of the power losses in equipment caused by the influence of harmonics. The result is original, because the developed methodology for calculating power consumption is used to assess the losses value, which includes all the above-mentioned research results. The results of the assessment are of great practical importance for oil producing enterprises (they are used by LLC LUKOIL PERM branch), because on their basis it can be concluded that with a fixed spectrum of harmonic components, the influence of harmonics can be neglected, which, firstly, makes it possible to avoid additional costs for the equipment installation for filtering harmonics, and, secondly, it makes it possible to reduce the cost of organizing monitoring systems (there is no need to constantly monitor the spectrum of harmonic components).

Also we made  minor corrections to Table 4. The measurements were carried out at the outputs of the control station after frequency conversion.

We appreciate your knowledge and desire to improve our research! Thank you for your attention!