Fast Driving Cycle Efficiency Optimization of Interior Permanent Magnet Synchronous Machines Considering PWM-Induced Harmonic Losses

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

1. In the Abstract, the authors propose incorporating PWM-induced harmonic losses into driving-cycle efficiency optimization, but the influence of these losses on the total loss and optimization results is not explained, making the research motivation insufficiently clear. The Abstract emphasizes the use of a rapid calculation method, while also stating that the computational time increases by 17 h; the reference basis for “rapid” should be clarified. The Abstract should also provide a more direct comparison before and after optimization. In addition, “THEFEA” seems to be “THFEA”; the abbreviation should be checked and unified.
2. In the Introduction, the paragraph discussing computational time contains confusing reference numbers and unclear logic. This paragraph should be rewritten, and it should be clarified whether the comparison of different computational times is based on the same computing platform.
3. The titles of Sections 2.1 and 2.2 are identical, and some contents are repeated. The main text states that the prototype is a 48-slot 8-pole IPMSM, whereas the “Number of poles” in Table 3 is 4. The authors should check and unify the relevant descriptions.
4. The manuscript assumes that the motor produces no torque when the vehicle is stationary or decelerating, which is equivalent to neglecting regenerative braking. This treatment may affect the distribution of representative points, the weight factors, and the weighted loss evaluation. The authors should explain the rationality of this assumption and its influence on the optimization results.
5. In Section 3, Lines 180–182 repeat previous content and should be deleted. In Line 205, “two structures” should be changed to “three structures”. In Line 214, “5id×5id” should be changed to “5id×5iq”. The authors should check and revise the relevant descriptions.
6. The description of Figure 8 in the main text is inconsistent with its caption. The data in Table 10 are inconsistent with the corresponding explanation in the main text. The authors should revise these issues and check whether similar inconsistencies among figures, tables, data, and textual descriptions exist throughout the manuscript.
7. The PWM-induced harmonic loss coefficients are extracted only at one weighted operating condition and the initial rotor position, and then used throughout the whole optimization process. The authors should explain the influence of this simplification on the Pareto ranking and the selection of the final optimized structure.

Author Response

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

This manuscript addresses a relevant problem in EV traction motor design: how to include PWM-induced harmonic losses in drive-cycle-based IPMSM efficiency optimization without making the optimization computationally heavy. The paper uses K-means representative operating points and small-signal THFEA-based fast calculation of PWM-induced harmonic losses. The topic is significant because PWM harmonic losses can be non-negligible in EV operation, and conventional PWM transient FEA is too expensive for iterative design optimization.

The contribution is useful but incremental. The individual components of the workflow are largely established in the literature; the main added value is their integration into a multi-objective cost/loss optimization and the demonstration that neglecting PWM-induced losses can select a different and inferior design. The comparison between Structure A and Structure B supports the central conclusion.
Reference list, Tables and Figures are generally useful, however, considering the comments below:

1. References 14 and 26 are not cited in the text.
2. Please check number of poles in the text and Table 3, whether it is 4 or 8.
3. Fig. 8 a legend typo.
4. The sentence in lines 403–405 says Structure B has larger PWM​ and total losses, but Table 10 shows Structure B has smaller PWM​ and total losses. Please check.
5. There are many repetitive fragments: Lines 117–121 and 128–132; 2.1 and 2.2 heading; 163-166 and 180-182; 424-429 and 434-438.
6. Please check the total loss claim: 3.11% or 3.0% as it is different in the abstract and conclusion.

Author Response

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have adequately addressed all of my comments, and the manuscript has been carefully revised.