Research on Multi-Dimensional MTPA Control for Five-Phase Interior Permanent Magnet Synchronous Motor
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe submitted manuscript proposes a multi-dimensional Maximum Torque Per Ampere (MTPA) control strategy based on virtual signal injection (VSI) for five-phase interior permanent magnet synchronous motors (FP-IPMSMs). The target of this work is to improve current utilization and torque output below base speed by utilizing both fundamental and third harmonic torque contributions. I have the following comments that may improve the overall quality of the manuscript.
- In the paper, the modeling part has many assumptions, e.g., negligible eddy currents and saturation, ignoring slotting effects. These assumptions should be justified, and their impact should be discussed in the text for high-performance practical motors.
- The authors are encouraged to add hardware details, for example, controller specifications, sampling rates, and inverter characteristics, in the revised manuscript.
- The authors claim a torque tracking error of below 5%; more systematic error analysis across different load/speed conditions could strengthen the claim of the method's robustness.
- Why is the proposed method not applied to different motor topologies, like surface-mounted PMSMs, or non-salient pole types?
- Many of the figures in the paper lack proper annotations. Sometimes, the plots don’t always specify units or axes, which makes it difficult to follow.
- The authors are suggested to make a comparison of the proposed method against other MTPA strategies. In particular, the classic lookup-table and online perturbation methods.
- A few typos in the paper need to the fixed in the revised paper.
- The English language at some places needs correction in terms of grammatical mistakes. Try to get it reviewed by a native speaker.
- A few typos in the paper need to the fixed in the revised paper.
- The English language at some places needs correction in terms of grammatical mistakes. Try to get it reviewed by a native speaker.
Author Response
Comment-1.In the paper, the modeling part has many assumptions, e.g., negligible eddy currents and saturation, ignoring slotting effects. These assumptions should be justified, and their impact should be discussed in the text for high-performance practical motors.
Reply-1: The assumptions in the modeling part of this paper, such as ignoring eddy current and saturation, and ignoring slotting effect, are reasonable and fully discussed, and professional understanding is relatively common. Their influence should not be discussed in this paper, because they do not affect the analysis of the motor and are of little significance.
Comment-2.The authors are encouraged to add hardware details, for example, controller specifications, sampling rates, and inverter characteristics, in the revised manuscript.
Reply-2: Details of the relevant hardware, such as controller specifications, sampling rates and inverter characteristics, have been added to the revised manuscript.
Comment-3.The authors claim a torque tracking error of below 5%; more systematic error analysis across different load/speed conditions could strengthen the claim of the method's robustness.
Reply-3: The torque tracking error of less than 5% is obtained under different load/speed conditions, which is sufficient to demonstrate the robustness of the method.
Comment-4.Why is the proposed method not applied to different motor topologies, like surface-mounted PMSMs, or non-salient pole types?
Reply-4: The method proposed in this paper is based on the model of salient pole motor. Because the model of salient pole motor is different from that of non-salient pole motor, the proposed algorithm cannot be applied to the topology of non-salient pole motor, but it can be applied to other polyphase salient pole motor structures.
Comment-5.Many of the figures in the paper lack proper annotations. Sometimes, the plots don’t always specify units or axes, which makes it difficult to follow.
Reply-5: Appropriate notes (units or axes) have been added to many of the figures in this paper in the newly revised version to facilitate reading and understanding the presentation of the paper.
Comment-6.The authors are suggested to make a comparison of the proposed method against other MTPA strategies. In particular, the classic lookup-table and online perturbation methods.
Reply-6: The classical table search method and online perturbation method are generally used for common non-convex motors, but the salient pole motor discussed in this paper is not suitable for the classical algorithm, if introduced, it will increase a lot of computation and some incomputable quantities, but the control algorithm discussed in this paper is sufficient.
Comment-7.A few typos in the paper need to the fixed in the revised paper.
Reply-7: Several typos in the paper have been corrected in the revised paper.
Comment-8.The English language at some places needs correction in terms of grammatical mistakes. Try to get it reviewed by a native speaker.
Reply-8: Some grammatical errors in the English language have been corrected in the new revised version of the paper, and native English speakers have given suggestions for corrections.
Reviewer 2 Report
Comments and Suggestions for AuthorsThe paper is written on the hot topic of improving the output torque-to-current ratio of a five-phase synchronous motor with internal permanent magnets (FP-IPMSM). The authors propose a multidimensional maximum torque per amp control strategy based on virtual signal injection. A mathematical model of FP-IPMSM containing the third harmonic is derived and a two-plane vector control is constructed.
The paper is recommended for publication after a slight revision of the caption to Figure 2.
On Figure 2 (Schematic stator current waveform after injecting the third harmonic) it is not indicated what colour the curves with and without the third harmonic are. For example, it should be stated:
Figure 2: Schematic stator current waveform after injecting the third harmonic.
The curve of blue colour corresponds to the oscillogram of stator current without the third harmonic, The curve of red colour corresponds to the oscillogram of stator current with the third harmonic.
Author Response
Comment-1. The paper is recommended for publication after a slight revision of the caption to Figure 2.
Reply-1: The title of Figure 2 has been modified in the new revision.
Comment-2. On Figure 2 (Schematic stator current waveform after injecting the third harmonic) it is not indicated what colour the curves with and without the third harmonic are. For example, it should be stated:
Reply-2: In the newly revised version, relevant explanations have been added to the problem of the color of the third harmonic and the curve without the third harmonic in Figure 2 (schematic diagram of the stator current waveform after injecting the third harmonic).
Comment-3.Figure 2: Schematic stator current waveform after injecting the third harmonic.
Reply-3: In the newly revised version, the schematic diagram of the stator current waveform after injecting the third harmonic in Figure 2 has been modified.
Comment-4.The curve of blue colour corresponds to the oscillogram of stator current without the third harmonic, The curve of red colour corresponds to the oscillogram of stator current with the third harmonic.
Reply-4: Indeed, the blue curve corresponds to the stator current waveform without third harmonics, and the red curve corresponds to the stator current waveform with third harmonics, and appropriate instructions have been added in the newly revised version.
Reviewer 3 Report
Comments and Suggestions for AuthorsThe Abstract of the paper is adequate.
The Introduction chapter reviews high quality references in the related topic.
Fig. 4 and Fig. 5: please replace the kanji text from these figures for more readability.
In several figures (four) in mentioned the CBPWM abbreviation, what kind of Pulse Width Modulation means this? It's not mentioned in the paper plain text.
Fig. 9 - Fig. 16: these figures seems to be only simulation results for the reader, since no any clear details presented about the concrete experiments. For example, block diagram of the digital control system, picture of the digital control system used, details about the PWM converter used, what kind of software technology has been used for implementation, real-time experiments, etc.
Only a picture of the motor with its load is given (fig. 8).
Please convince the reader about the authors real-time measurements and experiments.
Major revision is recommended.
Author Response
Comment-1.Fig. 4 and Fig. 5: please replace the kanji text from these figures for more readability.
Reply-1: The Chinese characters in Figure 4 and Figure 5 have been replaced in the newly revised version.
Comment-2.In several figures (four) in mentioned the CBPWM abbreviation, what kind of Pulse Width Modulation means this? It's not mentioned in the paper plain text.
Reply-2: The abbreviation CBPWM, which means Carrier-Based Pulse Width Modulation, is mentioned in several figures (4), and an explanation has been added in the newly revised version.
Comment-3. Fig. 9 - Fig. 16: these figures seems to be only simulation results for the reader, since no any clear details presented about the concrete experiments. For example, block diagram of the digital control system, picture of the digital control system used, details about the PWM converter used, what kind of software technology has been used for implementation, real-time experiments, etc.
Reply-3: The simulation results in FIG. 9-16 are mainly to support the effectiveness and feasibility of the model and algorithm, and the relevant results are sufficient to support the conclusion. The block diagram of the digital control system and the picture of the digital control system used in the paper, as well as the detailed information of the PWM converter used, what kind of software technology is adopted, these information have been revised in the new revised version.
Comment-4.Only a picture of the motor with its load is given (fig. 8).
Reply-4: The picture of the motor and its load in Figure 8 is a physical representation of all the platforms and study objects.
Comment-5.Please convince the reader about the authors real-time measurements and experiments.
Reply-5: The main innovative design of this paper is the modeling and control strategy design of the five-phase salient pole motor. Relevant simulation experiments have been sufficiently explained and verified, and real-time measurement and experiments have been added as far as possible in the new revised version.
Reviewer 4 Report
Comments and Suggestions for AuthorsPlease follow the recommendations in the attached file
Comments for author File: 
Comments.pdf
Author Response
Comment-1.- In line 11, please place the acronym “MTPA” just after “maximum torque per ampere” instead of after “control strategy”.
Reply-1: The newly revised version has put the acronym "MTPA" after "maximum torque per ampere"
Comment-2.- In line 14, please use lowercase letters on “Control Strategy Based” like it was made in line 11.
Reply-2: The changes have been completed in the new revision version.
Comment-3.- In line 23, please use only one variable to define the saliency ratio, otherwise, define the variables for the d-axis and q-axis inductances.
Reply-3: The changes have been completed in the new revision version.
Comment-4.- The acronym “VSI” (Virtual Signal Injection) was defined in line 11, please use it instead of writing the whole phrase (lines 62, 83, 87, 95, 318, 322, 387, 402, 432, 462, 545, 548, 575, 576, and 594).
Reply-4: The changes have been completed in the new revision version.
Comment-5.- In lines 105-106 it is established that only the fundamental and 3rd harmonic components are used. Please support this assumption. Which is the highest amplitude of the harmonics that are not considered. Which percentage represents this amplitude compared to the fundamental harmonic to justify that it is neglected?
Reply-5: The changes have been completed in the new revision version.
Comment-6.- In Eq. (4) please indicate the angle between parenthesis: “(3??),(3(??−?)),(3(??−2?)),(3(??−3?)), (3(??−4?))”. Also, in Eqs. (7), (10), (11), (12), (13), (33), (34), and everywhere it is needed.
Reply-6: The changes have been completed in the new revision version.
Comment-7.- In Eq. (5), please write "12" instead of "/2".
Reply-7: The changes have been completed in the new revision version.
Comment-8.- In Figures 4 and 5, there are Chinese symbols. Please write the correspondent equations.
Reply-8: The changes have been completed in the new revision version.
Comment-9.- In page 490 it is written “Hz Hz” instead of “Hz”.
Reply-9: The changes have been completed in the new revision version.
Comment-10.- Please ensure all the variables are defined when presenting the equations.
Reply-10: The changes have been completed in the new revision version.
Comment-11.- In the Reference section, commonly, the journals’ names are written in italics, while the conferences’ names are not. Please verify the format with the Editorial Committee.
Reply-11: The changes have been completed in the new revision version.
Comment-12.- Please add 2 or 3 more up-to-date references; if possible, consider the Journal Energies.
Reply-12: The changes have been completed in the new revision version.
Round 2
Reviewer 3 Report
Comments and Suggestions for AuthorsThe paper looks appropriate for journal publication.
