Novel Design Method in Wireless Charger for SS Topology with Current/Voltage Self-Limitation Function

Round 1

Reviewer 1 Report

The paper presents the wireless power transfer resonance compensation method based on the series–series topology with a self-limitation function that achieves fault tolerance without additional components when the secondary circuit is in a short and open state.  The proposed topology has a self-limitation function that limits the voltage–ampere output. The proposed design method divides the primary inductance into a magnetizing inductance Lm and a virtual leakage inductance. The primary side capacitor resonates with the leakage inductance. The proposed topology operates with zero voltage switching (ZVS) over the entire load range. ZVS has the advantage of a reduced  turn-on loss under MOSFET switching what increases the efficiency.

In Figure 2 we can see the capacitor Cr. In the equation (7) there is the capacitor Cp (primary). Figure 3 presents something similar to Bode plots of the conventional resonance design in the SS topology. Figure 3 presents the Bode plots of the proposed design method. The authors write:

“(16)–(18) give the primary current Ip, output current Io, and output voltage Uo, respectively. As indicated by (17) and (18), the output current and output voltage have complex components, which shows nonlinear output characteristics.

In (17), the smaller the load resistance becomes, the more the real part converges, and the imaginary part becomes zero. In (18), the larger the load resistance becomes, the more the imaginary part converges, and the real part becomes zero”.

But there are not the equations (16) – (18) in the paper.

Figure 7 presents loosely coupled transformer 3D model, but we cannot find in the paper the schema of 3 layer primary coil.

The Funding section is funny and shows how the paper was untidily prepared.

The paper could be interesting but is very badly written and in its current state cannot be published.

Author Response

Please see the attachment.

Reviewer 2 Report

The problem intended to solve is explicitly highlighted. The proposed method is implemented and tested experimentally with clear contribution. References are appropriate. However, it is good to reference a 2021/2022 paper and do capitalise the first letters of the abbreviated words, throughout the paper. Minor formatting errors in the Table.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

In the paper the Authors propose a wireless charger with self-limitation of current and voltage. The idea consist in using a series LC resonance not for the total inductance of the primary windings as most often used, but for the leakage inductance only. The paper is mostly understandable, however there are several issues that must be improved before publication. In particular, due to missing crucial equations it was not possible to evaluate the whole manuscript.

 

1. The theoretical description must be improved. In the present form it is chaotic and not clear. Besides some of the equations are missing or misplaced:

-        what is the role of eqs. (4) and (5) in the context of the considered design?

-        Eq. (6) and Line 138: “The self-inductance Lp can be divided into Lm and Llkp” – what is the aim of introducing this in the conventional design? This should be rather introduced later when considering the proposed design.

-        Equations (10)-(15) are slightly misplaced,

-        Equations (16)-(18) are missing, therefore it is impossible to evaluate some parts of the manuscript,

-        Equations (19)-(21) appear suddenly below text which is not related with them.

 

2. Some fragments seem corrupted or strange, e.g.

-        Line 117: “converter to ... voltage”,

-        Line 148,

-        Line 226: “approximated approximately”.

 

3. Table 1 – were the parameter values assumed or calculated or measured?

 

4. Line 150, Figures 3b, 4b, Line 224: Incorrect use of “phasor” (“phasor graph”, “phase is close to zero”). Probably this should be “phase angle”.

 

5. Figures 3, 4: Is R the same as RL? If yes use RL, if not explain what is R.

 

6. Line 188-189, Line 259: What do you mean by “complex components” and “nonlinear output characteristics” or “non-linear changes”? Nonlinearity is usually related with nonlinear components and their UI characteristics. But in this case we have linear circuit (at least between the inverter and rectifier).

 

7. Minor remarks:

 -        Lines 163-4: “As illustrated in Fig. 3, …. the primary current rapidly increase” – Figure 3 concerns voltage, so this implication is not visible in Figure 3,

-        Figures 5, 9, 10, 11, 12, 13 are illegible – they are too small,

-        Figure 13: the legend is not necessary,

-        All abbreviations should be explained when used first time (e.g. LCT, FHA).

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The "bugs" were removed.

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

The Authors have improved the manuscript compared to the previous version. The crucial issue was adding the missing equations and clarify some fragments. This was done, although not fully. I still think some equations should be located better. In the present shape they are thrown in groups between paragraphs instead of introducing them step by step, which would be easier for readers. This is especially visible for equations (19)-(21), but also (10)-(15) and (16)-(18) could be better introduced into the manuscript. Also Eq. (22) should be checked for a typo (white rectangle). There are some typos throughout the manuscript.

Author Response

Please see the attachment.

Author Response File: Author Response.docx