Inrush Current Control of High Power Density DC–DC Converter

Round 1

Reviewer 1 Report

In this paper is presented the design of a 2KW-54V DC-DC converter, which incorporates an inrush current limiter.

The part on the introduction referred to the inrush current control is short, it must be enlarged adding recent developments.

There are some grammar mistakes like the expressions "[10].so, " in line 59 and "the Bulk" in line 79, and words like "indictor" in line 86 along the paper, thus a strict grammar revision must be carried out.

The organization of the paper which begins in line "97" can be considered as another paragraph.

The math variables named in text must present the same format as in the equations. The variable thold in line 125.

It is not necessary to use the dot after figure mentions, as in line 36 "Figure 1.", this is repeated along the paper.

Figure 4 is not appropriately introduced based on its relevance to the work.

The quality of the figures where there are presented circuits schemes must be improved.

For Figures 11 and 12, another graph must be added to show the detailed simulation waveforms of the inrush current of the system with and without the limiter.

Figures 14 and 15, it must be improved due that the current signals cannot be observed adequately. It can be by considering two graphs per Figure, or adding the left vertical axe to voltage, and the right vertical axe for current, for example.

The proposal of the paper is comparable with the UCC28950 soft starter function?

Figures 17 and 18 must be adjusted vertically to observed the signals clearly. It can be considered the same limits for vertical and horizontal axes, in order to show the results appropriately.

In Figure 20 can not be observed the start process, as Figure 19 does.

In Figure 21 the limits must be changed in order to observe the ripple of the signals.

The distribution of the losses shown in Figure 25 must be described more in detail.

There is not Figure 22.

The improvement of 99.6% to 99.7% in the power factor is not a strong argument for the expression in line 390-391, I think that this expression must be rewritten showing the obtained results.

 

Author Response

 

Reviewer report#1

 

 

 

Dear professor Dr

First of all, we want to express our thanks and gratitude for the constructive comments and discussions to improve the quality of our manuscript significantly.

 

 

 

 

• Comments and Suggestions for Authors and answers

In this paper is presented the design of a 2KW-54V DC-DC converter, which incorporates an inrush current limiter.

 

Comment#1

• The part on the introduction referred to the inrush current control is short, it must be enlarged adding recent developments.

 

Answer:

 

Change was done as follow:

• Introduction part about inrush current control circuit was organized to three paragraph not only one to explain:

1. The phenomena of the inrush current.
2. The previous work and the different methods used to reduce this current in practical industrial applications.

• This part was extended as refer in the manuscript from line 79 to line 108.
• Another references were used and added in the manuscript in order to extend the explanation of this part.

 

 

 

Comment#2

• There are some grammar mistakes like the expressions "[10].so, " in line 59 and "the Bulk" in line 79, and words like "indictor" in line 86 along the paper, thus a strict grammar revision must be carried out.

 

Answer:

 

Change was done as follow:

(Line 59 grammar mistake was solved refer to the manuscript)

(Line 79 grammar mistake was solved refer to the manuscript)

(Line 86 problem in word “indictor” was changed to Inductor refer to the manuscript)

(Extensive writing editing and another more grammars revision and correction was carried out refer to manuscript)

 

 

 

 

Comment#3

• The organization of the paper which begins in line "97" can be considered as another paragraph.

 

Answer:

 

Change was done as follow:

 This paragraph” First, simulation of the complete designed converter is performed” was organized as a new paragraph as refer in the manuscript line:116.

• Numbering was changed due to adding new paragraphs in the introduction part.

 

 

 

 

 

Comment#4

• The math variables named in text must present the same format as in the equations. The variable thold in line 125.

 

Answer:

 

Change was done as follow:

Math variable (t_hold) was presented with the same format in text and equation as refer in the manuscript lines:143 and 145, also this was applied for all variables name in all the equations and texts refer to the manuscript.

 

 

 

Comment#5

• It is not necessary to use the dot after figure mentions, as in line 36 "Figure 1.", this is repeated along the paper.

 

Answer:

 

Change was done as follow:

Mistake of using the dot after figure mentions was corrected as referred to the manuscript line No: 36, also for all the figures mentions in the manuscript.

 

Comment#6

• Figure 4 is not appropriately introduced based on its relevance to the work.

 

Answer:

 

Mistake was solved as follow:

• Figure 4 in the manuscript line:181 was changed for increasing its quality and resolution, also the important two waveforms (I_drain and V_GS) from the circuit were pointed in the schematic to represent the characteristic of the proposed circuit and the principle operation of our proposed controller.
• In order to clear relevance between the schematic circuit and the simulation results Figures 11 and 14 with detailed explanations were added to the manuscript as refer in lines 330 and 352 respectively, and paragraph at line:320:329 for figure 11 description, paragraph line: 344:351 for figure 14 description.

Comment#7

• The quality of the figures where there are presented circuits schemes must be improved.

 

Answer:

 

Change was done as follow:

change in circuit schematics and simulation results in order to increase quality and provide more details and parameters in circuits schematics and waveform was done as refer in the manuscript figures 1,2,3,4,5,8,9, 12, and 13.

 

Comment#8

• For Figures 11 and 12, another graph must be added to show the detailed simulation waveform of the inrush current of the system with and without the limiter.

 

Answer:

 

Another zoomed graph was added as follow:

• Figures 12 and 13 changed to two graph in each figure in order to clear observing the detailed simulation result at the point of the inrush current, where the current at the initial power application period (Max. overshoot) was zoomed and showed in the manuscript lines No:341 and343.
• For figures 12 and 13, we measured large time portion of the current waveform because we want clearly observe two values from this figure, First value, is the maximum inrush current at initial power application to the converter, the second value is the maximum current which draw in the DC-DC converter primary side at steady state operation which is about 8.20A and must be the same with the both cases, based on this current we can know the Iinrushpeak (assumed to be not more than 9A) which is the most important factor in our circuit design.

 

 

Comment#9

• Figures 14 and 15, it must be improved due that the current signals cannot be observed adequately. It can be by considering two graphs per Figure, or adding the left vertical axis to voltage, and the right vertical axis for current, for example.

 

Answer:

Change was done as follow:

• Figures 14 and 15 numbering changed to 15 and 16 due to adding a new figure to the manuscript.
• Both figures considered as two graphs one for voltage at the top and the other for current at the bottom side, resolution and fonts was improved and ZVS point is also pointed in the voltage waveform at the point of switching time for the both switches QA, QC in the converter primary two legs as referred in the manuscript lines:358 and 360

 

 

 

 

Comment#10

 

• The proposal of the paper is comparable with the UCC28950 soft starter function?

 

Answer:

 

1. Soft starter is a technique used to reduce the inrush current of the converters by controlling the duty cycle of the converter switches in the starting time period usually (10ms as given in datasheet of UCC28950 IC) in order to slowly charging of the input capacitance and reduce the inrush current. So, in this technique Inrush current also can be limit at the required value by choosing the soft starter time and then calculating the biasing resistance and capacitance using equations (1) and (2) given in the IC data sheet page 18.

                                               Link to UCC28950IC data sheet (Cross Ref)

2. Our proposal is also based on controlling the slew rate of the input capacitance charging in order to reduce the inrush current to the required value but without changing in the controller duty cycle. In this technique controlling of the slew rate occurred by controlling the gate charge characteristics of the MOSFET switch as explained in the manuscript.

 

• From 1 and 2, we can observe that:

 

1. UCC28950 soft starter also can be used to reduce the inrush current (4 A) looks like our proposal by appropriate choosing of the soft starter time and biasing resistance and capacitance of the soft starter pin in the UCC28950 IC.
2. UCC28950 soft starter is an analog technique only, but our circuit can be used with analog and digital converters.

 

 

 

Comment#11

• Figures 17 and 18 must be adjusted vertically to observed the signals clearly. It can be considered the same limits for vertical and horizontal axes, in order to show the results appropriately.

 

Answer:

 

In order to clearly observing the experimental results, the following changes have been done:

• Figures 17 and 18 numbering changed to 18 and 19 in manuscript lines:394 and 396.
• Figure 19 was changed with one more clear to observe the result well.
• In the manuscript lines 386-393, the detailed explanation of the experimental results of the current waveform was provided, in order to clearly observing the difference between two experimental result curves.

 

The following is the reason why there is a difference between current shape in figures in our manuscript:

 

• The most important value we want to show from these waveforms is the maximum value of the current at initial power application which was measured and mentioned at each curve bottom side. Also, waveform shape in both cases is not the same because the technique used to limit the inrush current may cause small change in waveform shape during the operation process to limit this current.
• The time scale for each waveform was different because there is some delay in starting of the current in case of using inrush current control circuit because this technique is depending on controlling the slew rate of the charging curve of the input capacitance to DC-DC converter as depicted in the new added figure 11 in manuscript line:330, which shows comparative between the slew rate of the input voltage to DC-DC converter with and without the using of the inrush current circuit.

 

• We measured this inrush current in lap as follow:

 

• inrush current is related to the high dv/dt occurred due to the input bulk capacitance charging rate at initial power application to the power supply, so for exact experiment measurement of this harmful current and in order to simulate the practical case in which this power supply used to supply any telecom device by connecting it directly to the supply mains (220V,50&60Hz) in our environment, in our lab we applied 220V at once to the input of the power supply (PFC stage input) and measure these currents for input of the PFC stage and DC-DC converter more than 5 times to be sure from the exactly inrush current and to design our proposed inrush current control circuit. During 5-times of measurement, switch and diode of the boost converter in PFC stage was damaged and changed more times because the PFC board from Infineon designed only for experiment purpose (mentioned in the designed PDF report of this board as in ref [43] in page No:4 section1.1) and didn’t have enough protection for the practical industrial use, so for using this board, 220V must be gradually applied to this circuit not at once, in this case we can’t get exact result for the inrush current.
• Practically, clear Observing of such these currents in lab is not easy because it’s occurred at very small period at the initial power application to the power supply circuit and need from us to extend the power supply circuit design to include more protections during measurement.
• in the future work we will consider to extend our work to design more protection circuits for the PFC and DC-DC converter.

Comment#12

• In Figure 20 cannot be observed the start process, as Figure 19 does.

 

 

Answer:

 

Mistake was solved as follow:

• In order to clearly observe the start process in the current waveform, curve was changed with another curve have one-time division more to the left side which clearly show that the start process of the PFC stage current waveform with inrush current control circuit, we adjust the measurement set in our scope to measure Max Value and it is appear in the bottom side of the figure in all current waveforms.
• Figure No:21 at the manuscript line 405.

 

 

Comment#13

• In Figure 21 the limits must be changed in order to observe the ripple of the signals.

 

Answer:

 

Limits was changed as follow:

• In my design consideration of DC-DC converter, output filter capacitance value was designed to limit the output voltage ripple peak to be less than 200mV, in order to show this experiment result clearly in the output voltage waveform, for the same time period, the voltage limit changed as shown in Figure 23 at the manuscript line:419, which is clearly shows the ripple voltage, also using measurement set in Teledyne Scope mean value and peak to peak ripple value of the output voltage had been measured which shows that the ripple peak to peak is about 35mV which is less than designed value(200mV)
• Also, output voltage regulation of the designed converter was added with different loading as refer in the manuscript figure 24 in the manuscript line:427.

 

 

 

Comment#14

• The distribution of the losses shown in Figure 25 must be described more in detail.

 

Answer:

Change was done as follow:

The paragraph which describe and explain the power supply power losses distribution was extended to explain the power losses and the reason of it for each component in the DC-DC converter stage as refer in the manuscript lines from 451-462.

 

 

 

Comment#15

• There is not Figure 22.

 

Answer:

Change was done as follow:

numbering of figures was changed to correct this mistake.

 

Comment#16

• The improvement of 99.6% to 99.7% in the power factor is not a strong argument for the expression in line 390-391, I think that this expression must be rewritten showing the obtained results.

 

Answer:

 

Exactly you are right professor, thanks a lot, “it is not strong argument”, in this part, just we try to prove that connecting of our proposed inrush current controlling circuit didn’t effect on the performance of the PFC stage by showing the no-change or reducing in power factor by using the proposed circuit, so this paragraph has been written again to introduce this in the manuscript lines 436, 437.

Author Response File: Author Response.pdf

Reviewer 2 Report

In this paper, a complete mathematical design of the main components of 2KW,54V  DC-DC converter stage is presented. A simple inrush current controlling circuit to eliminate the high inrush current which generated due to high input capacitor at the input side of the DC-DC converter is proposed in the front of 2KW, 54V DC-DC converter stage. Sever suggestions are as follows.

1. The quality of the article should be improved. Especially the subscript of the variable.
2. Because the major contribution is the inrush current controlling circuit, more waveform for voltages and currents in Fig. 4 should be provide to improve the readability of the circuit. Iinrush and Idrain should be pointed in Fig. 4.
3. The experimental result like Fig. 5 at the startup of the converter should be provided to check the operation of inrush current controlling circuit.
4. Why does the inrush current controlling circuit improve the PFC stage performance by reducing the total reactive power consumption?
5. The description of the symbols in the equations should be more clear, such as Tsmin, CHB, etc.

Author Response

Reviewer Report#2

 

Dear professor Dr

First of all, we want to express our thanks and gratitude for the constructive comments and discussions to improve the quality of our manuscript significantly.

 

 

 

 

Comments and Suggestions for Authors

1. In this paper, a complete mathematical design of the main components of 2KW,54V DC-DC converter stage is presented. A simple inrush current controlling circuit to eliminate the high inrush current which generated due to high input capacitor at the input side of the DC-DC converter is proposed in the front of 2KW, 54V DC-DC converter stage. Sever suggestions are as follows.

 

Comment#1

1. The quality of the article should be improved. Especially the subscript of the variable.

 

Answer:

 

Change was done as follow:

1. Paper quality especially schematic circuits, figures quality and resolution, equations variables and the subscript of the variables was checked and improved as refer in the manuscript.

 

 

2. Language and comprehensive editing for the writing mistakes in all manuscript lines was done, also, more description paragraphs and experimental results about the data analysis (losses distribution in Lines:452to 462, Voltage ripple components in Lines:413 to 420, voltage regulation in Lines: 422 to 428) were added to the manuscript.

 

 

 

3. In order to clearly presented my simulation and experiment results, change in results waveforms quality to be more clear and readable in figures (1,2,3,4,9,10, 12,13,15,16), also more waveforms (Figures 11 and 14 in simulation part& Figures 23 and 24 in experimental part) were added to the manuscript.

 

 

 

 

 

Comment#2

 

 

1. Because the major contribution is the inrush current controlling circuit, more waveform for voltages and currents in Fig. 4 should be provide to improve the readability of the circuit. Iinrush and I drain should be pointed in Fig. 4.

 

Answer:

 

 

Figure 4 Improved, and in simulation results, Figures 11 and 14 added to the manuscript

 

• Schematic circuit quality in Figure 4, Line No:181 was improved and the Idrain and VGS of the MOSFET was pointed in the circuit, for inrush current, can’t point it in the circuit because it is not exactly waveform of the circuit, but inrush current (defined as the overshoot which occurred in the input current of the DC-DC converter stage due to high dv/dt of the input bulk capacitance. Also can be obtained from the drain current waveform because the return current component of DC-DC converter equally to the drain current as shown in the figure 4), so inrush current is the value of the input converter current at the initial power application to the power supply circuit.

 

 

• The mean principle of the operation of this circuit is to control the slew rate of the charging time of the input capacitance to the DC-DC converter stage in order to reduce the high dv/dt and so on reduce the inrush current, therefore, voltage charging characteristics of the input capacitance to the DC-DC converter was measured as refer in the manuscript in figure 11, line No:330 , which show the increasing in the slew rate value of the charging voltage of the input capacitance to reduce the inrush current value at initial power application to the controlling circuit.

 

 

 

• Figure 14, line No:353 contain the VGS and Idrain current at the same figure in order to explain and show the important operation points in the curve looks like the MOSFET protection section where the zener diode will breakdown, also the Miller platu voltage(Vplt) in which the drain current and inrush current of the circuit will limited to the safe limit. Description of this figure also added in the manuscript line No:345-352

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1. The experimental result like Fig. 5 at the startup of the converter should be provided to check the operation of inrush current controlling circuit.

 

Answer:

In order to clear observing the operation of the proposed control circuit the following change was done:

 

VGS versus Idrain of the proposed technique

 

 

• in order to check the operation of the inrush current controlling circuit, as shown in the above curve, MOSFET characteristics of VGS and Idrain was obtained from the simulation results and this curve was added to the manuscript as refer in manuscript line 353, figure No:14, also the details explains about the important operation points in this figure was explained in the manuscript paragraph from lines 345 to 352.

 

• From this char’s we can notice:
• [1] The gate source plateau voltage required for desired peak drain current (Inrush current) about 4.25V as calculated from equation (4) in the manuscript line 207.
• [2] The peak drain current which related to the peak inrush current about 6.40A as shown in the simulation results in Figure 13 in the manuscript line 343.
• [3] The protection area of the MOSFET when the zener diode was break downed before the break down voltage of the used MOSFET(30V) in order to protect the MOSFET from the high input voltage applied from the PFC stage to the DC-DC converter stage.

 

 

• In simulation process, we didn’t assume or neglect any parameter of the MOSFET switch used in our work, all parameters were obtained from the chosen switch datasheet (STMelectronics company switch based on the reference [39] in the manuscript) to obtain exact and closest result to the practical circuit (Experimental) operation characteristics.

 

 

• Handling looks like this curve in experimental results can’t be done 100%. In the experimental environment, only the constant voltage part of the VGS and constant current part of the Idrain can be observed using the scope in our lab, but the important part of the curve at the beginning where the principle of the circuit operation will take place during controlling of the inrush current can’t be handled in the experiment environment, this is due to:

 

• Controlling of the inrush current occurred so fast in very small period of the circuit operation time at the initial power application to the power supply, and require special type of scopes to exactly observing this response. So, in order to save time and cost we first, simulate our designed converter and the proposed inrush current controlling circuit using simulation software to observe these characteristics and then we performed the proposed tested circuit in the experimental environment.

 

 

• [1]. Sathishkumar, P., T. N. V. Krishna, Muhammad Adil Khan, Kamran Zeb, and Hee-Je "Digital soft start implementation for minimizing start up transients in high power DAB-IBDC converter." Energies 11, no. 4 (2018): 956.
• [2]. Bukhari, Syed Sabir Hussain, Shahid Atiq, and Byung-il Kwon. "Elimination of the inrush current phenomenon associated with single-phase offline UPS systems." Energies 9, no. 2 (2016): 96.
• [3]. Eleni Manousaka. DC-DC Buck Converter with Inrush Current Limiter. Master Thesis. faculty of applied sciences TU delft, October 2013.

 

Previous three references present a different control techniques used in reducing the inrush current of the different types of the converter circuits Ref [1] also due to the difficulty to observe the exact technique char’s during the operation of reducing the inrush current, simulation software used first in order to enhance the principle of the circuit operation then experimental results only shows the voltage and current waveforms of the input /output side of the converter. Ref [2] presented a technique about elimination of the inrush current for power supply UPS system, in [2] char’s also with and without proposed technique was tested using simulation software and in experimental results only presented the current with and without using the proposed technique. In [3] the author presented a technique using MOSFET switch in order to reduce the inrush current of the 250W DC-DC Buck converter, also in [3] experimental results didn’t handle the exact result 100% so the author used Multisim software in order to obtain the chars of the circuit technique.

 

 

• As I mentioned in the manuscript this inrush current controlling circuit was designed to work with any converter type (analog or digital). So, we already started to digitilize the controller of the power supply two stages using DSP MCU from TEXAS INSTRUMENTS, we will consider this point in the future work by extending our lap and circuit measurements to include this experimental characteristic as well as simulation characteristics in our future work.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1. Why does the inrush current controlling circuit improve the PFC stage performance by reducing the total reactive power consumption?

 

Answer:

 

There are two reasons for the reducing of the power supply reactive power:

 

1. Charging control circuit which designed to protect the MOSFET in the proposed controlling circuit from the high output voltage of the PFC stage, this protection circuit contain capacitance (C₁=100uF), connected in parallel with the output side of the PFC converter. This capacitance works also as reactive power compensation which supply some of the reactive power required during the converter operation, causing that the total reactive power absorbing from the AC input power supply will be reduced.

 

 

2. Most of the absorbed circuit reactive power consumed at the converter starting operation due to the high starting current, and high phase shift between voltage and current waveforms. therefore, controlling this current to reduce the inrush current of the AC-DC power supply two stages, leads also to reduce the total reactive power consumption at the starting period of the AC-DC power supply.

 

 

 

 

1. The description of the symbols in the equations should be more clear, such as Tsmin, CHB, etc.

 

Answer:

 

Change have been done as follow:

• Clear Description of the equation symbols and how we calculated it in our work was clearly represented in the manuscript after each equation.
• T_smin, CHB description and how we can get each value have been added to the manuscript lines No: from 251 to 254.

 

 

 

Author Response File: Author Response.pdf

Reviewer 3 Report

Dear authors, the theme is interesting and actual. The number of references is appropriate. In general, you need to improve your English. You need to uniformize the space between the values and units. You need to put the punctuation in the equations. You need to uniformize the text for the achromous, for example, “power factor correction (PFC)” and “Electromagnetic Interference (EMI)”, because you have one with capital letters. When referring figures in the text do not put punctuation after the number. I will describe some mistakes that I detect in the paper:

 - In line 22, change “Phase shift zero” to “phase shift zero”;

 - In line 40, change “High input power” to “high input power”;

 - In line 41, change “shaft between two waveforms” to “shift between them”;

 - In line 59, change “side [10].so, one” to “side [10]. So, one”;

 - In line 62 you have “dual half bridge” and in line 64 you have “Dual-half-bridge”, you need to uniformize;

 - In line 64 you have “Phase-Shift” and in line 92 you have “Phase shift”, you need to uniformize;

 - In line 76, change “1KW” to “1 kW”. Sometimes you confuse the K (Kelvin);

 - In line 79, change “the Bulk” to “The Bulk”;

 - In line 91, change “In this paper;” to “In this paper,”;

 - In line 92, you have space between the value and the unit (2 kW), you need to uniformized in paper;

 - In line 105, you do not have end punctuation in the figure legend;

 - In line 106, you need to put capital letters in subsubsection;

 - In line 112, you have the references in two lines, put it on one line;

 - In line 114, in figure 2 the lines are not aligned;

 - In line 115, change “schematic” to “Schematic”;

 - In line 124, you need to put capital letters in subsubsection;

 - In line 128, put the description in one paragraph;

 - In line 133, you need to put capital letters in this subsubsection and next;

 - In line 140, change “inrush” to “Inrush” and put punctuation;

 - In line 160, change “Voltage as shown in equ (2)” to “voltage as shown in (2)”;

- In line 162, change the text resolution in figure 4;

 - In line 172, change “Cgs, So Cgd” to “Cgs. So Cgd”;

 - In line 177, change “Figure 5. When” to “Figure 5 when”;

 - In line 183, change “Where gf” to “where gf”;

 - In line 192, change “Where” to “where” and put it on start line;

 - In line 200, change “value of This current” to “value of this current”;

 - In line 200, change “Iinrush” to “Inrush”;

 - In line 209, change “MOSFET. also, we” to “MOSFET. Also, we”;

 - In line 215, in table 1 you need to start the table head in capital letters and change “Iinrush” to “Inrush”;

 - In line 225, change “Where” to “where”, and you do not have punctuation in the end of the paragraph;

 - In line 235, put the description in one paragraph;

 - In line 240, the paragraph is confusing;

 - In line 245, you need to put the description in one paragraph;

 - In line 260, change “Control” to “control”;

 - In line 270, you do not have end punctuation in the figure legend;

 - In line 275, change “sensed. to” to “sensed. To”;

 - In line 283, you need to start the table head in capital letters;

 - In line 283, inside the table 2 change “Output Indictor” to “Output Inductor”;

 - In line 292, you do not have end punctuation in the figure legend and you need to start the phrase with a capital letter;

 - In line 297, 305 and 307, you do not have end punctuation in the figure legend;

 - In line 305, you do not have end punctuation in the figure legend;

 - In line 308, change “Figure 13. shows the Gate Charging” to “Figure 13 shows the gate charging”;

 - In line 313, you do not have end punctuation in the figure legend and you need to start the phrase with a capital letter;

 - In line 318 and 320, you need to start the phrase with a capital letter;

 - In line 322, change “The Complete” to “The complete”;

 - In line 337, change “2.5KW” to “2.5 kW”;

 - In line 343, change “Figure 17 and 18. Shows” to “Figure 17 and 18 shows”;

 - In line 349, 354 and 356, you need to start the phrase with a capital letter;

 - In line 350, change “Figure 19 and 20. Shows” to “Figure 19 and 20 shows”;

 - In line 362, you forget to finish the figure legend;

 - In line 372 and 382, you do not have end punctuation in the figure legend;

 - In line 375, you do not have end punctuation in the figure legend and you need to change “propsed” to “proposed”;

 - In line 399, change “passive elements. phase shifted” to “passive elements. Phase shifted”.

Author Response

 

 

Reviewer report#3

 

 

Dear professor Dr,

First of all, we want to express our thanks and gratitude for the constructive comments and discussions to improve the quality of our manuscript significantly.

 

 

 

 

Comments and Suggestions for Authors

Dear authors, the theme is interesting and actual. The number of references is appropriate. In general, you need to improve your English. You need to uniformed the space between the values and units. You need to put the punctuation in the equations. You need to uniformed the text for the achromous, for example, “power factor correction (PFC)” and “Electromagnetic Interference (EMI)”, because you have one with capital letters. When referring figures in the text do not put punctuation after the number. I will describe some mistakes that I detect in the paper:

• In line 22, change “Phase shift zero” to “phase shift zero”;

(change have been done refer to the manuscript line No:22)

 

 

• In line 40, change “High input power” to “high input power”;

(change have been done refer to the manuscript line No:40)

 

 

• In line 41, change “shaft between two waveforms” to “shift between them”;

(change have been done refer to the manuscript line No:41)

 

• In line 59, change “side [10].so, one” to “side [10]. So, one”;

(change have been done refer to the manuscript line No:59)

 

 

• In line 62 you have “dual half bridge” and in line 64 you have “Dual-half-bridge”, you need to uniformed;

(dual half bridge in lines 62 and 64 was uniformed as refer in the manuscript)

 

 

• In line 64 you have “Phase-Shift” and in line 92 you have “Phase shift”, you need to uniformed;

(phase shift in lines 64 and 110 was uniformed as refer in the manuscript)

Line No. changed due to adding new paragraphs in the introduction part from line 79 to 108.

 

 

• In line 76, change “1KW” to “1 kW”. Sometimes you confuse the K (Kelvin);

(change have been done refer to the manuscript line No:76)

Kilo was changed to be small letter also, in order to uniformed all texts, all the spaces between values and units were removed (1kW, 400V, 25uH ….and so on)

 

 

• In line 79, change “the Bulk” to “The Bulk”;

(change have been done refer to the manuscript line No:79)

 

 

 

• In line 91, change “In this paper;” to “In this paper,”;

(change have been done refer to the manuscript line No:109)

 

 

• In line 92, you have space between the value and the unit (2 kW), you need to uniformed in paper;

(change have been done where the space between the value and the unit was removed as refer in the manuscript lines 12 and 110)

 

 

• In line 105, you do not have end punctuation in the figure legend;

(change have been done refer to the manuscript line No:124)

All figures legend has been checked and end punctuation was added

 

 

 

• In line 106, you need to put capital letters in sub subsection;

(change have been done refer to the manuscript line No:125)

 

 

 

• In line 112, you have the references in two lines, put it on one line;

(change have been done refer to the manuscript line No:131)

 

 

• In line 114, in figure 2 the lines are not aligned;

(change have been done refer to the manuscript line No:132)

 

 

 

• In line 115, change “schematic” to “Schematic”;

(change have been done refer to the manuscript line No:133)

 

 

 

• In line 124, you need to put capital letters in sub subsection;

(change have been done refer to the manuscript line No:142)

 

 

 

• In line 128, put the description in one paragraph;

(change have been done refer to the paragraph in manuscript lines 146, 147)

• In line 133, you need to put capital letters in this subsubsection and next;

(change have been done refer to the paper line No:149)

All subsections arranged again to be capital letters.

 

 

 

• In line 140, change “inrush” to “Inrush” and put punctuation;

(change have been done refer to the manuscript line No:163)

 

 

 

• In line 160, change “Voltage as shown in equ (2)” to “voltage as shown in (2)”;

(change have been done refer to the manuscript line No:179)

 

 

 

• In line 162, change the text resolution in figure 4;

(Text resolution was improved, Text font was increased and more details related to circuit characteristics was introduced in the figure as refer to the manuscript line 181)

 

 

 

• In line 172, change “Cgs, So Cgd” to “Cgs. So Cgd”;

(change have been done refer to the manuscript line No:191)

 

 

 

• In line 177, change “Figure 5. When” to “Figure 5 when”;

(change have been done refer to the manuscript line No:197)

 

• In line 183, change “Where gf” to “where gf”;

(change have been done refer to the manuscript line No: 203)

 

 

 

• In line 192, change “Where” to “where” and put it on start line;

(change have been done refer to the manuscript line No:212)

 

 

 

• In line 200, change “value of This current” to “value of this current”;

(change have been done refer to the manuscript line No:220)

 

 

• In line 200, change “Iinrush” to “Inrush”;

(change have been done refer to the manuscript line No:220)

 

 

 

 

• In line 209, change “MOSFET. also, we” to “MOSFET. Also, we”;

(change have been done refer to the manuscript line No:229)

 

 

 

• In line 215, in table 1 you need to start the table head in capital letters and change “Iinrush” to “Inrush”;

(change have been done refer to the manuscript Table.1 in the line No: 236)

 

 

 

 

• In line 225, change “Where” to “where”, and you do not have punctuation in the end of the paragraph;

(punctuation was added and change have been done refer to the manuscript line No: 245)

 

 

 

• In line 235, put the description in one paragraph;

(change have been done refer to the paragraph in the manuscript lines from 251-254)

 

 

• In line 240, the paragraph is confusing;

(In order to obtain the ZVS condition we need to exhaust the energy from the parasitic capacitance of the switches and transformer winding in the primary side, this can be occurred by connect a device with appropriate value to absorb this energy such as the resonant inductor so (Inductors (L_r and L_lk) energy must exhaust the capacitance energy in the primary side))

 

(I changed the paragraph arrangement to be more clear as refer to the manuscript lines from 261-265)

 

 

• In line 245, you need to put the description in one paragraph;

(change have been done refer to the manuscript line 267 and L_LK was removed from this paragraph because it is defined in the previous paragraph in line No:263)

 

 

 

 

• In line 260, change “Control” to “control”;

(change have been done refer to the manuscript line No:281)

 

 

 

 

• In line 270, you do not have end punctuation in the figure legend;

(change have been done refer to the manuscript line No:290)

 

 

• In line 275, change “sensed. to” to “sensed. To”;

(change have been done refer to the manuscript line No:295)

 

 

 

 

 

• In line 283, you need to start the table head in capital letters;

(change have been done refer to the manuscript table 2 in the line No:303)

 

 

 

 

• In line 283, inside the table 2 change “Output Indictor” to “Output Inductor”;

(change have been done refer to the manuscript line No:303 inside the table 2)

 

 

 

 

• In line 292, you do not have end punctuation in the figure legend and you need to start the phrase with a capital letter;

(change have been done refer to the manuscript line No:312)

 

 

 

• In line 297, 305 and 307, you do not have end punctuation in the figure legend;

(changes have been done refer to the manuscript lines 318, 341 and343)

 

 

 

 

 

• In line 305, you do not have end punctuation in the figure legend;

(change have been done refer to the manuscript line No:341)

 

 

 

 

 

• In line 308, change “Figure 13. shows the Gate Charging” to “Figure 13 shows the gate charging”;

(change have been done refer to the manuscript line No:345)

a new curve was added to the figure and paragraph description in the manuscript lines:345 to 352 was changed.

 

 

 

• In line 313, you do not have end punctuation in the figure legend and you need to start the phrase with a capital letter;

(change have been done refer to the manuscript line No:354)

 

 

 

 

• In line 318 and 320, you need to start the phrase with a capital letter;

(change have been done refer to the manuscript lines 358 and 360)

 

• In line 322, change “The Complete” to “The complete”;

(change have been done refer to the manuscript line No:363)

 

 

 

• In line 337, change “2.5KW” to “2.5 kW”;

(change have been done refer to the manuscript line No:381 and there is no space between the value and the unit as mentioned previously in this report and this is uniformed for all manuscript)

 

 

 

 

• In line 343, change “Figure 17 and 18. Shows” to “Figure 17 and 18 shows”;

(change have been done refer to the manuscript line No:386)

 

 

 

 

• In line 349, 354 and 356, you need to start the phrase with a capital letter;

(DC-DC is the start of the phrase and it was capitalized for all figures legend in the manuscript lines 395, 397 and 404)

 

 

 

• In line 350, change “Figure 19 and 20. Shows” to “Figure 19 and 20 shows”;

(change have been done refer to the manuscript line No:398)

 

 

 

 

 

• In line 362, you forget to finish the figure legend;

(change have been done refer to the figure 22 in the manuscript line No:411)

 

 

 

 

• In line 372 and 382, you do not have end punctuation in the figure legend;

(change have been done refer to the manuscript lines 439 and 442)

 

 

 

• In line 375, you do not have end punctuation in the figure legend and you need to change “propsed” to “proposed”;

(change have been done refer to the manuscript line No:442)

 

 

 

• In line 399, change “passive elements. phase shifted” to “passive elements. Phase shifted”.

(change have been done refer to the paper line No:476)

 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

In the introduction, I think that recent proposals in the literature must be added, due that the more recent proposal is from 2013, this is to show the relevance of the work.
Also, it must be added some lines which present the advantages of the use of MOSFETS to the control of the inrush current, this because there are presented some techniques but not the advantages of the last one.

Line 112 indicates the proposal of a circuit, but there are no clear contributions about the existing works. Thus it must be added some lines to explain why the proposal is a new contribution.

In line 115 is commented that the proposal complies with the standard IEC61000 but in work, there is not more information, so it must be added a paragraph in the results which validates this argument.

The quality of the figures in the work must be improved. I think that figures must be in the same or similar format, i.e. appropriate font size, same style, vertical-horizontal scale, among others. This because some figures present a huge font (e.g. Fig. 3), others a small font (e.g. Fig. 6), higher horizontal scale (e.g. Fig. 1.)

 

 

Author Response

Review#1 second round

 

 

 

Dear professor Dr

First of all, we want to express again our thanks and gratitude for the constructive comments and discussions to improve the quality of our manuscript significantly.

 

Comments and Suggestions for Authors

• [1] In the introduction, I think that recent proposals in the literature must be added, due that the more recent proposal is from 2013, this is to show the relevance of the work. Also, it must be added some lines which present the advantages of the use of MOSFETS to the control of the inrush current, this because there are presented some techniques but not the advantages of the last one.

 

Change was done as follow:

 

• In introduction part:

 

1. Literature review of the inrush current was extended in to 4-paragraphes in the manuscript lines No: (79-115) in order to add advantages of using MOSFET switch in our proposal in the manuscript lines No: (106-115).

 

2. More recent references about current controlling using the gate charge transfer characteristics of the MOSFET switches were added to the manuscript lines No: (600-609) as following:

 

[1] Dias, Agnaldo Vieira, José Antenor Pomilio, and Saulo Finco. A current limiting switch for applications in 600 space power systems. In 2017 IEEE Southern Power Electronics Conference (SPEC), 4 Dec 2017, pp. 1-6.

 

[2] Fuengwarodsakul, Nisai H. Battery management system with active inrush current control for Li-ion 603 battery in light electric vehicles. Electrical Engineering. 2016, 98, pp. 17-27.

 

[3] Musumeci, S. Gate charge control of high-voltage Silicon-Carbide (SiC) MOSFET in power converter 605 applications. In 2015 International Conference on Clean Electrical Power (ICCEP), 16 Jun 2015, pp. 709-715.

 

[4] Marroqui, David, Ausias Garrigos, Jose M. Blanes, and Roberto Gutierrez. Photovoltaic-Driven SiC MOSFET Circuit Breaker with Latching and Current Limiting Capability. Energies. 2019, 12, 4585.

 

 

• [2] Line 112 indicates the proposal of a circuit, but there are no clear contributions about the existing works. Thus it must be added some lines to explain why the proposal is a new contribution.

 

Change was done as follow:

 

• Paragraph about the Main advantages of our proposal was added in the manuscript lines 121:126.

 

 

• [3] In line 115 is commented that the proposal complies with the standard IEC61000 but in work, there is not more information, so it must be added a paragraph in the results which validates this argument.

 

Change was done as follow:

• The following first table shows the standard codes numbers for the different limitations in design of the power supply.

 

• The most important parameter for our design (DC-DC) converter stage is the limitation of the voltage fluctuation in the load side with different loading condition which is must be not more than 3.3% of the load voltage as shown in the following second table.

 

• One writing mistake in the manuscript Line No:115 was corrected, which Standard code in the manuscript for the limitation for the output voltage of the power supply was corrected to IEC61000-3-3, not IEC61000-3-2.

 

• From the Load voltage& power characteristics in the manuscript figure 24, it is noticed that the maximum change for the load voltage is not more than 1V ( ) which is less than the standard limit value (3.3%) as shown in the above second table.

 

• In the manuscript lines 439-440 paragraph was extended in order to validate this argument.

 

• Reference [48] for the standard IEC61000 has been added to the manuscript. Also attached in this report as shown in the following figures.

 

• [4] The quality of the figures in the work must be improved. I think that figures must be in the same or similar format, i.e. appropriate font size, same style, vertical-horizontal scale, among others. This because some figures present a huge font (e.g. Fig. 3), others a small font (e.g. Fig. 6), higher horizontal scale (e.g. Fig. 1.)

 

Change was done as follow:

 

• [1]. All figures which represent schematics and characteristics were considered in the same format, same font in text, same style and same lines width as refer in the manuscript:

 

• Figure 1 in the manuscript line No: 136
• Figure 2 in the manuscript line No: 145
• Figure 3 in the manuscript line No: 174
• Figure 4 in the manuscript line No: 193

drew with the same format and font style, which represent the proposed circuit implementation in the PSIM software.  

• Figure 5 in the manuscript line No: 195
• Figure 6 in the manuscript line No: 199
• Figure 8 in the manuscript line No: 301

 

• [2]. For the simulation results, also all figures considered with the same format same fonts, style and line width, also for voltages and current waveforms, in order to compare and clear observe the difference with and without using the proposed circuit, the same vertical-horizontal scale has been considered as refer in the manuscript:

 

• Figure 9 in the manuscript line No: 324
• Figure 10 in the manuscript line No: 330
• Figure 11 in the manuscript line No: 342

 X-scale was increased to be all the running period looks like the power curve in the figure 9

• Figure 12 in the manuscript line No: 354
• Figure 13 in the manuscript line No: 356

considered to be with the same scale with figure 12 in order to clear observe the difference of the current with and without proposed circuit.

• Figure 14 in the manuscript line No: 366
• Figure 15 in the manuscript line No: 371
• Figure 16 in the manuscript line No: 373

 

• [3]. For the experimental results the figures readjusted again which the main results scope figures were added to the manuscript without any zoom or change in dimensions in order to increase the resolution of the figures.

Author Response File: Author Response.pdf

Reviewer 3 Report

Dear authors, the paper is ready to publish. I only suggest improving the resolution of the images.

Author Response

Reviewer report#3

 

 

Dear professor Dr

First of all, we want to express again our thanks and gratitude for the constructive comments and discussions to improve the quality of our manuscript significantly.

 

 

Comments and Suggestions for Authors and answers

 

Dear authors, the paper is ready to publish. I only suggest improving the resolution of the images.

Change was done as follow:

 

• [1]. All figures which represent schematics and characteristics were considered in the same format, same font in text, same style and same lines width as refer in the manuscript:

 

• Figure 1 in the manuscript line No: 136
• Figure 2 in the manuscript line No: 145
• Figure 3 in the manuscript line No: 174
• Figure 4 in the manuscript line No: 193

drew with the same format and font style, which represent the proposed circuit implementation in the PSIM software. 

• Figure 5 in the manuscript line No: 195
• Figure 6 in the manuscript line No: 199
• Figure 8 in the manuscript line No: 301

 

• [2]. For the simulation results, also all figures considered with the same format same fonts, style and line width, also for voltages and current waveforms, in order to compare and clear observe the difference with and without using the proposed circuit, the same vertical-horizontal scale has been considered as refer in the manuscript:

 

• Figure 9 in the manuscript line No: 324
• Figure 10 in the manuscript line No: 330
• Figure 11 in the manuscript line No: 342

 X-scale was increased to be all the running period looks like the power curve in the figure 9

• Figure 12 in the manuscript line No: 354
• Figure 13 in the manuscript line No: 356

considered to be with the same scale with figure 12 in order to clear observe the difference of the current with and without proposed circuit.

• Figure 14 in the manuscript line No: 366
• Figure 15 in the manuscript line No: 371
• Figure 16 in the manuscript line No: 373

 

• [3]. For the experimental results the figures readjusted again which the main results scope figures were added to the manuscript without any zoom or change in dimensions in order to increase the resolution of the figures.

 

Author Response File: Author Response.pdf