Prosecution Insights
Last updated: April 19, 2026
Application No. 18/546,558

METHOD FOR SELECTING A CHOPPING FREQUENCY OF AN INVERTER CONTROLLING AN ELECTRIC MACHINE, AND CORRESPONDING DEVICE

Non-Final OA §103§112
Filed
Aug 15, 2023
Examiner
DINH, THAI T
Art Unit
2846
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Nidec Psa Emotors
OA Round
1 (Non-Final)
86%
Grant Probability
Favorable
1-2
OA Rounds
2y 5m
To Grant
86%
With Interview

Examiner Intelligence

Grants 86% — above average
86%
Career Allow Rate
558 granted / 651 resolved
+17.7% vs TC avg
Minimal -0% lift
Without
With
+-0.1%
Interview Lift
resolved cases with interview
Typical timeline
2y 5m
Avg Prosecution
27 currently pending
Career history
678
Total Applications
across all art units

Statute-Specific Performance

§101
3.1%
-36.9% vs TC avg
§103
49.4%
+9.4% vs TC avg
§102
23.4%
-16.6% vs TC avg
§112
20.8%
-19.2% vs TC avg
Black line = Tech Center average estimate • Based on career data from 651 resolved cases

Office Action

§103 §112
DETAILED ACTION Notice of Pre-AIA or AIA Status The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . Claim Rejections - 35 USC § 112 The following is a quotation of 35 U.S.C. 112(b): (b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention. The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph: The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention. Claim 4 recites the limitation "the torque setpoint" in lines 11-12. There is insufficient antecedent basis for this limitation in the claim. Claim Rejections - 35 USC § 103 In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status. The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action: A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made. Claims 1-5 and 8-13 are rejected under 35 U.S.C. 103 as being unpatentable over Nomura et al. (hereinafter Nomura, US 2007/0052382 A1) in view of Suhama et al. (hereinafter Suhama, US 2013/0169206 A1). For claim 1, Nomura discloses a method for selecting a chopping frequency for application thereof to an inverter controlling a rotating electric machine (Figs. 1-3 of Nomura discloses a method for selecting a chopping frequency for application thereof to an inverter 104 controlling a rotating electric machine 110 – see Nomura, Figs. 1-3, paragraphs [0032]-[0040] and [0042]-[0043]), wherein the chopping frequency is chosen from among multiple predetermined frequencies depending on the position, in a map, of a current operating point of the assembly formed by the electric machine and the inverter, the map having at least the rotational speed of the electric machine or the frequency of the electric current applied thereto as parameter (Figs. 1-3 of Nomura discloses the chopping frequency is chosen from among multiple predetermined frequencies (2kHz -12kHz) depending on the position, in a map (Fig. 3), of a current operating point of the assembly formed by the electric machine 110 and the inverter 104, the map having at least the rotational speed of the electric machine (Fig. 3, motor speed) or the frequency of the electric current applied thereto as parameter – see Nomura, Figs. 1-3, paragraphs [0032], [0039]-[0040], and [0044]), wherein in at least part of the map, the chopping frequency is furthermore chosen based on a parameter representative of a thermal condition of the electronic switches contained in the inverter (see Nomura, Figs. 1-3, paragraphs [0040] and [0043]-[0044]). Nomura is silent for disclosing in a nominal operation area of the assembly formed by the electric machine and the inverter, the chopping frequency is chosen from among three different chopping frequencies, namely a first chopping frequency, a second chopping frequency, and a third chopping frequency, and wherein the map defines three parts in the nominal operation area, namely a first part, a second part and a third part, and wherein: - when the current operating point of the assembly formed by the electric machine and the inverter is positioned in the first part, the first chopping frequency is chosen, - when the current operating point of the assembly formed by the electric machine and the inverter is positioned in the second part, the second chopping frequency is chosen or the third chopping frequency is chosen, depending on the parameter representative of the thermal condition of the electronic switches contained in the inverter, and - when the current operating point of the assembly formed by the electric machine and the inverter is positioned in a third part, the third chopping frequency is chosen. However, Suhama discloses in a nominal operation area of the assembly formed by the electric machine and the inverter, the chopping frequency is chosen from among three different chopping frequencies, namely a first chopping frequency, a second chopping frequency, and a third chopping frequency (Figs. 1-4 of Suhama disclose, in a nominal operation area of the assembly formed by the electric machine M1 and the inverter 14, the chopping frequency fs is chosen from among three different chopping frequencies, namely a first chopping frequency fs1, a second chopping frequency fs2, and a third chopping frequency fs3 – see Suhama, Figs. 1-4, paragraphs [0047], [0051] and [0061]-[0064]), wherein the map defines three parts in the nominal operation area, namely a first part, a second part and a third part (Fig. 4 of Suhama discloses the map defines three parts in the nominal operation area, namely a first part (Fig. 4, region 0<N< N1 and T>T1), a second part (Fig. 4, region N1<N<N2) and a third part (Fig. 4, region 0<N<N1 and T<T1 in combining region N1<N<N2 and T<T2), and wherein: - when the current operating point of the assembly formed by the electric machine and the inverter is positioned in the first part, the first chopping frequency is chosen (Figs. 3-4 of Suhama disclose the current operating point of the assembly formed by the electric machine M1 and the inverter 14 is positioned in the first part (Fig. 4, region: 0<N< N1 and T>T1), the first chopping frequency fs1 is chosen -- see Suhama, Fig. 4, paragraph [0061]-[0062]), - when the current operating point of the assembly formed by the electric machine and the inverter is positioned in the second part, the second chopping frequency is chosen or the third chopping frequency is chosen, depending on the parameter representative of the thermal condition of the electronic switches contained in the inverter (Figs. 3-4 of Suhama disclose the current operating point of the assembly formed by the electric machine M1 and the inverter 14 is positioned in the second part (Fig. 4, region N1<N<N)), the second chopping frequency fs2 is chosen if T>T2 or the third chopping frequency fs3 is chosen if T<T2, depending on the parameter representative of the thermal condition T of the electronic switches contained in the inverter 14 -- see Suhama, Fig. 4, paragraph [0061]-[0062]), and - when the current operating point of the assembly formed by the electric machine and the inverter is positioned in a third part, the third chopping frequency is chosen (Figs. 3-4 of Suhama disclose the current operating point of the assembly formed by the electric machine M1 and the inverter 14 is positioned in a third part (Fig. 4, region 0<N<N1 and T<T1 in combining region N1<N<N2 and T<T2), the third chopping frequency fs3 is chosen -- see Suhama, Fig. 4, paragraph [0061]-[0062]). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to modify teaching of Nomura to incorporate teaching of Suhama for purpose of reducing both noise in the power control system and loss in motor. For claim 2, Nomura in view of Suhama disclose the method according to claim 1, wherein - the first part of the map corresponds to the part of the nominal operation area positioned up to a first threshold of the rotational speed of the electric machine or of the frequency of the electric current applied thereto (Fig. 4 of Suhama discloses the first part (Fig. 4, region 0<N< N1 and T>T1) of the map corresponds to the part of the nominal operation area positioned up to a first threshold N1 of the rotational speed of the electric machine M1 or of the frequency fs1 of the electric current applied thereto -- see Suhama, Fig. 4, paragraph [0061]-[0062]), - the second part of the map corresponds to the part of the nominal operation area positioned above the first threshold of the rotational speed of the electric machine or of the frequency of the electric current applied thereto and which extends up to a second threshold of the rotational speed of the electric machine or of the frequency of the electric current applied thereto (Fig. 4 of Suhama discloses the second part (Fig. 4, region N1<N<N2) of the map corresponds to the part of the nominal operation area positioned above the first threshold N1 of the rotational speed of the electric machine M1 or of the frequency fs2 of the electric current applied thereto and which extends up to a second threshold N2 of the rotational speed of the electric machine M1 or of the frequency (fs2/fs3) of the electric current applied thereto -- see Suhama, Fig. 4, paragraph [0061]-[0062]), - the third part of the map corresponds to the part of the nominal operation area positioned above the second threshold of the rotational speed of the electric machine or of the frequency of the electric current applied thereto (Fig. 4 of Suhama discloses the third part (Fig. 4, region 0<N<N1 and T<T1 in combining region N1<N<N2 and T<T2) of the map corresponds to the part of the nominal operation area positioned above the second threshold N2 of the rotational speed of the electric machine M1 or of the frequency fs3 of the electric current applied thereto -- see Suhama, Fig. 4, paragraph [0061]-[0062]). For claim 3, Nomura in view of Suhama disclose the method according to claim 1, wherein - the first part of the map corresponds to the part of the nominal operation area positioned up to a first threshold of the rotational speed of the electric machine or of the frequency of the electric current applied thereto (Fig. 4 of Suhama discloses the first part (Fig. 4, region 0<N< N1 and T>T1) of the map corresponds to the part of the nominal operation area positioned up to a first threshold N1 of the rotational speed of the electric machine M1 or of the frequency fs1 of the electric current applied thereto -- see Suhama, Fig. 4, paragraph [0061]-[0062]), - the second part of the map corresponds to the part of the nominal operation area positioned above the first threshold of the rotational speed of the electric machine or of the frequency of the electric current applied thereto and above a threshold of an intensity setpoint of the current to be applied to the electric machine or of a torque setpoint (Fig. 4 of Suhama discloses the second part (Fig. 4, region N1<N<N2) of the map corresponds to the part of the nominal operation area positioned above the first threshold N1 of the rotational speed of the electric machine M1 or of the frequency fs2 of the electric current applied thereto and above a threshold of an intensity setpoint of the current to be applied to the electric machine M1 or of a torque setpoint T2 -- see Suhama, Fig. 4, paragraph [0061]-[0062]. It is noted that torque is proportional to current in an electric machine. Thus, the threshold of intensity setpoint of the current is considered obviously as threshold of torque), - the third part of the map corresponds to the part of the nominal operation area positioned above the first threshold of the rotational speed of the electric machine or of the frequency of the electric current applied thereto and which extends up to the threshold of the intensity setpoint of the current to be applied to the electric machine or of the torque setpoint (Fig. 4 of Suhama discloses the third part (Fig. 4, region 0<N<N1 and T<T1 in combining region N1<N<N2 and T<T2) of the map corresponds to the part of the nominal operation area positioned above the first threshold N1 of the rotational speed of the electric machine M1 or of the frequency fs3 of the electric current applied thereto and which extends up to the threshold of the intensity setpoint of the current to be applied to the electric machine or of the torque setpoint T1/T2 -- see Suhama, Fig. 4, paragraph [0061]-[0062]). For claim 4, Nomura discloses a method for selecting a chopping frequency for application thereof to an inverter controlling a rotating electric machine (Figs. 1-3 of Nomura discloses a method for selecting a chopping frequency for application thereof to an inverter 104 controlling a rotating electric machine 110 – see Nomura, Figs. 1-3, paragraphs [0032]-[0040] and [0042]-[0043]), wherein the chopping frequency is chosen from among multiple predetermined frequencies depending on the position, in a map, of a current operating point of the assembly formed by the electric machine and the inverter, the map having at least the rotational speed of the electric machine or the frequency of the electric current applied thereto as parameter (Figs. 1-3 of Nomura discloses the chopping frequency is chosen from among multiple predetermined frequencies (2kHz -12kHz) depending on the position, in a map (Fig. 3), of a current operating point of the assembly formed by the electric machine 110 and the inverter 104, the map having at least the rotational speed of the electric machine (Fig. 3, motor speed) or the frequency of the electric current applied thereto as parameter – see Nomura, Figs. 1-3, paragraphs [0032], [0039]-[0040], and [0044]), wherein in at least part of the map, the chopping frequency is furthermore chosen based on a parameter representative of a thermal condition of the electronic switches contained in the inverter (see Nomura, Figs. 1-3, paragraphs [0040] and [0043]-[0044]). Nomura is silent for disclosing the map further includes, as parameter, the torque setpoint to be applied to the electric machine or the intensity setpoint of the current to be applied to the electric machine by the inverter. However, Suhama discloses the map further includes, as parameter, the torque setpoint to be applied to the electric machine or the intensity setpoint of the current to be applied to the electric machine by the inverter (Figs. 3-4 of Suhama disclose the map further includes, as parameter, the torque setpoint Trq to be applied to the electric machine M1 or the intensity setpoint of the current to be applied to the electric machine M1 by the inverter 14 – see Suhama, Figs. 3-4, paragraphs [0060]-[0064]). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to modify teaching of Nomura to incorporate teaching of Suhama for purpose of reducing both noise in the power control system and loss in motor. For claim 5, Nomura in view of Suhama disclose the method according to claim 1, wherein the parameter representative of the thermal condition of the switches of the inverter is a measured temperature of the switches or estimated temperature of the switches based on the operating parameters of the inverter over time (Figs. 1-3 of Nomura discloses the parameter representative of the thermal condition of the switches 111-116 of the inverter 104 is a measured temperature of the switches or estimated temperature of the switches based on the operating parameters of the inverter over time – see Nomura, Figs. 1-3, paragraphs [0040] and [0043]-[0044]). For claim 8, Nomura in view of Suhama disclose the method according to claim 1, wherein the first chopping frequency is less than the second chopping frequency, and the second chopping frequency is less than the third chopping frequency (see Suhama, Fig. 4, paragraph [0063]). For claim 9, Nomura in view of Suhama disclose the method according to claim 8, wherein: - the first chopping frequency (Fig. 4 of Suhama, fs1) is comprised between 4 kHz and 6 kHz (Nomura in view of Suhama is silent for disclosing the specific first chopping frequency which is comprised between 4 kHz and 6 kHz. However, Fig. 3 of Nomura disclose the chopping frequency between 2 kHz and 12kHz; and Suhama discloses frequency fs fluctuates within the range of a large region from the low frequency region (see Suhama, Fig. 4, paragraphs [0063]-[0064]). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to modify teaching of Nomura in view of Suhama to have specific first chopping frequency between 4 kHz and 6 kHz for purpose of performing specific functions of a particular application); - the second chopping frequency (Fig. 4 of Suhama, fs2) is comprised between 6 kHz and 9 kHz (Similarly, Nomura in view of Suhama is silent for disclosing the specific second chopping frequency which is comprised between 6 kHz and 9 kHz. However, Fig. 3 of Nomura disclose the chopping frequency between 2 kHz and 12kHz; and Suhama discloses frequency fs fluctuates within the range of a large region from the low frequency region (see Suhama, Fig. 4, paragraphs [0063]-[0064]). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to modify teaching of Nomura in view of Suhama to have specific second chopping frequency between 6 kHz and 9 kHz for purpose of performing specific functions of a particular application); - the third chopping frequency (Fig. 4 of Suhama, fs3) is comprised between 9 kHz and 12 kHz (Similarly, Nomura in view of Suhama is silent for disclosing the specific third chopping frequency which is comprised between 9 kHz and 12 kHz. However, Fig. 3 of Nomura disclose the chopping frequency between 2 kHz and 12kHz; and Suhama discloses frequency fs fluctuates within the range of a large region from the low frequency region (see Suhama, Fig. 4, paragraphs [0063]-[0064]). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to modify teaching of Nomura in view of Suhama to have specific second chopping frequency between 9 kHz and 12 kHz for purpose of performing specific functions of a particular application). For claim 10, Nomura in view of Suhama disclose tyhe method according to claim 1, wherein when the rotational speed of the electric machine exceeds a maximum rotational speed such that the operating point of the assembly exits the nominal operation area, a fourth chopping frequency is chosen, the fourth chopping frequency being greater than the third chopping frequency (Fig. 4 of Suhama discloses when the rotational speed N of the electric machine M1 exceeds a maximum rotational speed N2 such that the operating point of the assembly exits the nominal operation area, a fourth chopping frequency fs4 is chosen, the fourth chopping frequency fs4 being greater than the third chopping frequency fs3 – see Suhama, Figs. 3-4, paragraphs [0062]-[0063]). For claim 11, Nomura in view of Suhama disclose a method for controlling an inverter controlling a rotating electric machine, the control method including the steps of: - implementing a method for selecting a chopping frequency according to claim 1 (see explanation in claim 1 above), - applying the chosen chopping frequency to the inverter (see Nomura, Figs. 1-3, paragraphs [0032]-[0041]). Claims 12 is an apparatus claim which is either same or similar to combination of “a method” claim 1 and claim 11. The explanation is omitted. For claim 13, Nomura in view of Suhama disclose an electric motor vehicle (Suhama discloses an electric motor vehicle – see Suhama, Fig. 1, paragraphs [0002], [0030] and [0045]-[0046]) including a device according to claim 12 (see explanation in claim 12 above). Claims 6-7 are rejected under 35 U.S.C. 103 as being unpatentable over Nomura et al. (hereinafter Nomura, US 2007/0052382 A1) in view of Suhama et al. (hereinafter Suhama, US 2013/0169206 A1), further in view of Youn et al. (hereinafter Youn, US 2018/0054153 A1). For claim 6, Nomura in view of Suhama disclose the method according to claim 1, wherein the parameter representative of the thermal condition of the switches is a function of the current voltage of a battery for powering the inverter and the electric machine (Fig. 1 of Nomura discloses the parameter representative of the thermal condition of the switches 111-116 via temperature measuring section 106 – see Nomura, Fig. 1, paragraph [0039]. Nomura discloses power source 101 and a rectifier 103 which supply a DC voltage for powering the inverter 104 and the electric machine 110 – see Nomura, Fig. 1, paragraphs [0034]-[0035]. It is well-known in art that power source 101 and a rectifier 103 can be replaced by a battery for powering the inverter and the electric machine. Also, the thermal condition of the switches is directly proportional to voltage. Thus, thermal condition of the switches is a function of the current voltage of the battery. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to modify teaching of Nomura to include a battery instead of power source and a rectifier, and thermal condition of the switches is a function of the current voltage of the battery to meet the design criteria of a particular application). Nomura and Suhama are silent for disclosing the parameter representative of a temperature of a coolant present in a coolant circuit of the inverter. However, Youn discloses the parameter representative of a temperature of a coolant present in a coolant circuit of the inverter (see Youn, Figs. 1-3 and 5, paragraphs [0026]-[0031] and [0033]). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to modify teaching of Nomura in view of Suhama to incorporate teaching of Youn for purpose of reducing loss of a switching frequency of the inverter. For claim 7, Nomura in view of Suhama, further in view of Youn disclose the method according to claim 6, wherein when the current operating point of the assembly formed by the electric machine and the inverter is positioned in the second part of the map, wherein the second chopping frequency is chosen if the temperature of the coolant at the inlet of the inverter is above a predefined value positioned between 50 °C and 90 °C, and if the voltage of the battery is greater than a predefined voltage comprised between 300 V and 380 V, and the third chopping frequency is chosen if these conditions are not met (Nomura, Suhama and Youn do not disclose specific second chopping frequency is chosen if the temperature of the coolant at the inlet of the inverter is above a predefined value positioned between 50 °C and 90 °C, and if the voltage of the battery is greater than a specific predefined voltage comprised between 300 V and 380 V, and the third chopping frequency is chosen if these conditions are not met. However, Nomura obviously discloses thermal condition of the switches is a function of the current voltage of the battery (see explanation in claim 6 above); Suhama discloses second and third chopping frequencies (see Suhama, Fig. 4); and Youn discloses switching frequency of inverter which is adjusted based on the monitored temperature of the coolant (see Youn, Figs. 1-3 and 5, abstract, paragraphs [0030]-[0031] and [0033]). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to modify teaching of Nomura in view of Suhama, further in view of Youn to include when the current operating point of the assembly formed by the electric machine and the inverter is positioned in the second part of the map, wherein the second chopping frequency is chosen if the temperature of the coolant at the inlet of the inverter is above a predefined value positioned between 50 °C and 90 °C, and if the voltage of the battery is greater than a predefined voltage comprised between 300 V and 380 V, and the third chopping frequency is chosen if these conditions are not met to meet the design criteria of a particular application). Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to THAI T DINH whose telephone number is (571)270-3852. The examiner can normally be reached (571)270-3852. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, EDUARDO COLON-SANTANA can be reached at (571)272-2060. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /THAI T DINH/Primary Examiner, Art Unit 2846 Nov 1, 2025
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Prosecution Timeline

Aug 15, 2023
Application Filed
Nov 01, 2025
Non-Final Rejection — §103, §112 (current)

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Expected OA Rounds
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Grant Probability
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2y 5m
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