FPGA-Based Frequency Tracking Strategy with High-Accuracy for Wireless Power Transmission Systems

Round 1

Reviewer 1 Report

 In order to solve the problem of current and voltage phase lag caused by various factors in the WPT system, the paper proposes a frequency tracking method based on an FPGA to accurately track the current and voltage phase differences on the transmitting side. Frequency tracking system and control block diagram are built. The experimental results show that the system always works under the ZVS state. In the range of over-coupling conditions, the output power and transmission efficiency are significantly improved compared with the fixed frequency system. The idea is very interesting and the English is well written. Nevertheless, the theoretical analysis of this article is a little insufficient and the theoretical analysis of this article is a little insufficient.

There are some weak points that must be strengthen or clarify in this paper, some key concerns are given as follows.

 

1. The author should explain in more detail how changes in distance and load affect the WPT system

 

2. According to KVL equations, the input impedance angle (j) is the same with the lead angle (a), and it’s a common sense that ZVS achieves when a>0. In this article, the author proposes a frequency tracking method based on an FPGA to accurately track the current and voltage phase differences on the transmitting side. However, parameter optimization design of WPT system is lacked in this paper.

 

3. The theoretical analysis of voltage phase acquisition is lacked in this paper.

 

4. The author should explain the basis for selection of voltage and current phase difference margin

 

5. The voltage phase angle in Fig.9(b) is written incorrectly, please correct it

 

6. The article lacks pictures of simulation pictures. If possible, please add it.

 

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

-The Frequency tracking control system should be explained more understandable (line 225-272), 

- In fig.8 the coils are not visible enough, 

-In the 4.3. Frequency tracking experiment  due to the large amount of data the main point (essence) cannot be followed. Please improve. 

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

The author describes the “FPGA-Based Frequency Tracking Strategy with High-Accuracy for Wireless Power Transmission Systems”. This paper is quite interesting from a technological point of view. I recommended a minor revision of the manuscript.

The minor suggestion below:

1. The author should rewrite the abstract and give the merit of the work.
2. The language is too poor. The author should recheck the grammatical and typo errors in the manuscript.
3. The figure quality is too poor and the author should improve the quality of the images.
4. What is the main advantage of FPGA?
5. How will the coil distance cause the voltage and current phase differences?

 

 

Author Response

Please see the attachment

Author Response File: Author Response.pdf