Open-Circuit Fault-Tolerant Control of a Six-Phase Asymmetric Permanent Magnet Synchronous Motor Drive System
Round 1
Reviewer 1 Report
1- The English language of the text should be improved.
2- The present verbs should be used in the Abstract.
3- There are some edition errors and mistakes that should be revised.
4- The paper is well organized. Also, comparing the simulation results with an actual test system is another advantage of this study. However, the Abstract should be revised to highlight the contributions and novelties.
5- Addressing some quantitative findings and the advantages of the study in the abstract are suggested.
6- Adding a nomenclature is suggested.
7- The literature review should be improved. Recent relevant papers should be cited and reviewed.
8- Adding a flowchart showing the step-by-step procedures for implementing the proposed method is suggested.
9- The changes in id in Fig. 12c should be discussed in detail Why this occurs?
1- [1], [2], … have been given besides the sub-figures. Why? They should be revised.
Author Response
Dear reviewer:
Thank you for your decision an constructive comments on my manuscript.we have carefully considered the suggestion of reviewer and make some changes.we have tried our best to improve and made some changes in the manuscript.
The yellow part that has been revised according to your comments. Revision notes,point-to-point, are given as follows:
1- The English language of the text should be improved.
The article has been fully improved in English by native speakers.
2- The present verbs should be used in the Abstract.
The tense of the sentences in the summary has been changed into the present tense.
3-There are some edition errors and mistakes that should be revised.
The article was edited to use latex studio and format errors which have been corrected.
4-The paper is well organized. Also, comparing the simulation results with an actual test system is another advantage of this study. However, the Abstract should be revised to highlight the contributions and novelties.
Thank you for your suggestion and the last part of the summary was amended:
Finally, the PMSM drive system principle prototype was tested. By comparing the waveforms of output torque and current of each phase before and after fault tolerance, it can be seen that the large torque fluctuation (5%) before fault tolerance was suppressed to 2% and smoothed out. The effectiveness of fault tolerance control was verified.
5-Addressing some quantitative findings and the advantages of the study in the abstract are suggested.
We agree with you and some quantitative findings and the advantages of the study in the abstract have been involved both in abstract and the article content.
6-Adding a nomenclature is suggested.
We agree with you that a nomenclature should be involved. Due to space limitations, only a small amount of nomenclature is shown.
7-The literature review should be improved. Recent relevant papers should be cited and reviewed.
Recent relevant papers had be cited and reviewed such follows:
Zhang Z, Wu Y, Su H, Sun Q. Research on Open-circuit Fault Tolerant Control of Six-phase Permanent Magnet Synchronous Machine Based on Fifth Harmonic Current Injection. Journal of Electrical Machines and Systems, Chinese Electrotechnical Society (English), 2022,3:06
Lv K, Dong X Zhu C , Research on Fault-Tolerant Operation Strategy of Permanent Magnet Synchronous Motor with Common DC Bus Open Winding Phase-Breaking Fault, Energies,2022, 15
Le, Duc Dung and Hong, Sihyeong and Lee, Dong Choon. Fault detection and tolerant control for flying-capacitor modular multilevel converters feeding induction motor drives, Journal of Power Electronics. 2022,22(06):947-958
Xue qing Wang，Zheng Wang, Zhixian Xu. A Hybrid Direct Torque Control Scheme for DualThree-phase PMSM Drives with Improved Operation Performance, IEEE Transactions on Power Electronics, 2018,pp(2):1-1
Zhang, L, Dong, C, Wang, Y, Han, S.Research on Fault-Tolerant Field-Oriented Control of a Five-Phase Permanent Magnet Motor Based on Disturbance Adaption, Energies,2022, 15
Xueqing Wang, Zheng Wang, Zhixian Xu, Jiangbiao He, Wenxiang Zhao. Diagnosis and Tolerance of Common Electrical Faults in T-Type Three-Level Inverters Fed Dual Three-Phase PMSM Drives", IEEE Transactions on Power Electronics, 2020
Luo Yixiao, Liu Chunhua. Pre- and Post-Fault Tolerant Operation of a Six-Phase PMSM Motor Using FCS-MPC Without Controller Reconfiguration. IEEE Transactions on Vehicular Technology.2018
Yixiao Luo, Chunhua Liu.Model Predictive Control for a Six-Phase PMSM Motor With a Reduced Dimension Cost Function,IEEE Transactions on Industrial,Electronics, 2019,pp(99)1-1
8-Adding a flowchart showing the step-by-step procedures for implementing the proposed method is suggested.
We agree with you but can we not use flowcharts？
9- The changes in id in Fig. 12c should be discussed in detail Why this occurs?
The following contents have been added to the article:
The IGBT drive signal of the bridge arm of phase A is removed at time T. As can be seen from the figure, the current of phase A becomes zero after 0.3s. Phase B and phase C own the same amplitude and complementary waveforms. Phase D, E and F waveforms have different degrees of amplitude and phase changes, and large torque fluctuations occurs.
According to the Figure 12(b) and Figure 12(c), it can be seen that lower current harmonics are obtained after voltage compensation is applied. At the same time, the sinusoidal and zero-current waveforms of the A-phase currents alternate and the torque remain smooth at all times, while the currents in phase D & E start to change in the opposite direction to each other, which is achieved by the missing bus voltage balancing capability of the three inverters, A,B & C, which is compensated by the three-phase D, E & F sound inverter during fault tolerance. At the same time, after the fault occurred, the original large torque fluctuations were suppressed and smoothed out due to the applied fault-tolerant control, and the test results verified the effectiveness of the fault-tolerant control.
10- [1], [2], … have been given besides the sub-figures. Why? They should be revised.
The [1], [2], …had been removed.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Dear authors,
Please give some simulation results considering open circuit faults in different places (different switches).
Please discuss the neutral voltage.
How can the system detect fault type or any fault occurrence?
Let's assume the motor is rotating a fan load. would your method be successful?
Author Response
Dear reviewer:
Thank you for your decision an constructive comments on my manuscript.we have carefully considered the suggestion of reviewer and make some changes.we have tried our best to improve and made some changes in the manuscript.
The yellow part that has been revised according to your comments. Revision notes,point-to-point, are given as follows:
1-Please give some simulation results considering open circuit faults in different places (different switches).
It can be seen from the content of the article that different phases of the open circuit have similar conclusions in lines.
Meanwhile, the open-circuit fault tolerance scheme based on equations, from (9) to (24), can be applied in any phase, while in the case of a two-phase open-circuit fault, the voltage of the faulty phase can still be compensated by other normal phases.
2-Please discuss the neutral voltage.
The following questions regarding the discussion of neutral point voltages are included in the paper:
Each switching tube is subjected to half of the DC voltage when the neutral point voltage of the three-level inverter is balanced. Whereas, the switching tubes are subjected to unequal voltages when the phase is missed. When an open-circuit fault occurs in one phase, whether the neutral point is isolated or not and how the neutral point is connected also correspond to different reduced-dimensional decoupling transformation matrices. This paper is an asymmetrical six-phase PMSM with two windings of a six-phase motor with isolated neutral operating independently. The two windings differs from each other by 30 degrees. In this case, both windings have their own constraints after a phase loss fault, i.e. the total current of phase A, B & C is zero and the total current of phase D, E & F is zero.
3-How can the system detect fault type or any fault occurrence?
The following questions regarding the discussion of neutral point voltages are included in the paper:
The fault indication variable for phase loss faults in the drive system can be derived according to the VSD theory and the constraints on the post-fault current. The system can determine that the fault indication variable exceeds the threshold value to lock out the phase loss fault and thus implement fault-tolerant control.
4-Let's assume the motor is rotating a fan load. would your method be successful?
The motor has been gradually applied in some fields with relatively high requirements for reliability, power level and power density, such as aerospace, naval propulsion, rail transportation, electric vehicles. If the motor of suitable capacity is allowed to drive the fan, fault-tolerant control is not guaranteed due to the relatively small load.
Author Response File: Author Response.pdf
Reviewer 3 Report
Paper presents an interesting study, but some issues, such as follows, need to be addressed:
- please revise the text overlapping from page 6, line 123;
- please revise the title of paragraph 2.3;
- please revise Fig. 8 format and complete it with the identification of phases for a better readability;
- please revise in lines 248-253: "the harmonic-free vector set on the x-y subspace is utilized in the design of simplified SVM to effectively optimize the voltage vector synthesis and reduce the motor current harmonics in combination with the implementation of harmonic current controller, which reduces the torque fluctuation and is verified by The test results were verified, while the controller also did not need to change the control structure of the DTC;"; meaning is unclear;
- please highlight more the main author contributions in comparison with other performed studies;
- conclusion section should be extended;
- pay attention to punctuation in the entire paper.
Author Response
Dear reviewer:
Thank you for your decision an constructive comments on my manuscript.we have carefully considered the suggestion of reviewer and make some changes.we have tried our best to improve and made some changes in the manuscript.
The yellow part that has been revised according to your comments. Revision notes,point-to-point, are given as follows:
1- please revise the text overlapping from page 6, line 123;
Thank you very much for your seriousness. The overlapping from page 6, line 123 text has been removed to the latex.
2- please revise the title of paragraph 2.3;
Thank you very much for your seriousness. The paragraph 2.3 has been changed.
3- please revise Fig. 8 format and complete it with the identification of phases for a better readability;
Fig. 8 has been changed in the text
4- please revise in lines 248-253: "the harmonic-free vector set on the x-y subspace is utilized in the design of simplified SVM to effectively optimize the voltage vector synthesis and reduce the motor current harmonics in combination with the implementation of harmonic current controller, which reduces the torque fluctuation and is verified by The test results were verified, while the controller also did not need to change the control structure of the DTC;"; meaning is unclear;
The proposed DTC-SVM control strategy does not require any changes of the DTC structure. According to the simplified SVM, the voltage vector synthesis has been effectively optimized by the harmonic-free vector set in the x-y subspace. The harmonic current controller has been combined with the harmonic current controller to reduce the current harmonics of the motor, and the torque ripple suppression in the open-circuit fault mode has been realized.
5-please highlight more the main author contributions in comparison with other performed studies;
Thank you very much for your seriousness.
6-conclusion section should be extended;
The conclusion section had been extended.
7-pay attention to punctuation in the entire paper.
Thank you for your review, all punctuation has been reviewed and corrected in the paper.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The authors have tried to respond to review comments.
Reviewer 2 Report
Accept
