Prosecution Insights
Last updated: April 19, 2026
Application No. 18/703,364

METHOD FOR IMPROVING EFFICIENCY OF MICRO-INVERTER AND DUAL-ACTIVE-BRIDGE-TYPE MICRO-INVERTER

Non-Final OA §103
Filed
Apr 22, 2024
Examiner
QUDDUS, NUSRAT
Art Unit
2838
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Shanghai Jiao Tong University
OA Round
1 (Non-Final)
89%
Grant Probability
Favorable
1-2
OA Rounds
2y 9m
To Grant
95%
With Interview

Examiner Intelligence

Grants 89% — above average
89%
Career Allow Rate
719 granted / 808 resolved
+21.0% vs TC avg
Moderate +6% lift
Without
With
+5.9%
Interview Lift
resolved cases with interview
Typical timeline
2y 9m
Avg Prosecution
16 currently pending
Career history
824
Total Applications
across all art units

Statute-Specific Performance

§101
0.2%
-39.8% vs TC avg
§103
51.3%
+11.3% vs TC avg
§102
34.8%
-5.2% vs TC avg
§112
11.3%
-28.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 808 resolved cases

Office Action

§103
DETAIL 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 . This Office Action is in response to Applicant’s filing on 04/22/2024. Priority Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55. Claim Rejections - 35 USC § 103 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. 5. Claims 1, 14 are rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (“Li”, US Pat 10454381), in further view of Nasiri et al. (“Nasiri”, US Pat 11689092). Regarding independent claim 1, Li teaches (Fig. 8; col. 3 L31-41 and col. 6 L4-col. 7 L25) a method for improving the efficiency of an inverter, characterized by comprising: performing power modulation mode switching of a dual-active-bridge-type (DAB) inverter (i.e., using bidirectional power flow between DC to AC), such that the power is bi-directionally transmitted from a DC side (102) to an AC side (100) and from the AC side (100) to the DC side (102), thereby reducing an effective value of a secondary side current of a transformer (high-frequency transformer’s (HFT) secondary winding (SW) receiving current (I SW) from primary side current (I PW) in 50); and according to a modulation mode (i.e., grid tired mode, stand-alone inverter mode or critical conduction mode) switching characteristic of the dual-active-bridge- type inverter (DAB) within a power frequency period (i.e., frequency range or period), performing (i.e., using control loops of ‘110, 120, 130, 140’) hybrid optimization on a turn ratio (i.e., winding ratio of HFT on PW vs. SW) of a primary side to a secondary side and a transformer leakage inductance of a high-frequency transformer (HFT’s SW receiving current (I SW) from primary side current (I PW) in 50) of the dual-active-bridge-type (DAB) micro-inverter. However, Li fails to explicitly teach use of a micro-inverter. However, Nasiri explicitly teaches old well-established technique for use of a micro-inverter (micro-inverters or AC-module inverter with a high-frequency transformers (HFTs) embedded in an AC-DC-DC DAB converters, known as high-frequency-link inverter. See, col. 1 L24-col. 2 L20). Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified Li’s methods being explicitly used for a micro-inverter, as doing so would have provided an improved efficiency within the converter with high power capability and current control, as taught by Nasiri (col. 1 L32-64). Regarding claim 14, Li teaches (Fig. 8; col. 3 L31-41 and col. 6 L4-col. 7 L25) a dual-active-bridge-type (DAB) inverter, implements the method according to claim 1. However, Li fails to explicitly teach use of a micro-inverter. However, Nasiri explicitly teaches old well-established technique for use of a micro-inverter (micro-inverters or AC-module inverter with a high-frequency transformers (HFTs) embedded in an AC-DC-DC DAB converters, known as high-frequency-link inverter. See, col. 1 L24-col. 2 L20). Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified Li’s methods being explicitly used for a micro-inverter, as doing so would have provided an improved efficiency within the converter with high power capability and current control, as taught by Nasiri (col. 1 L32-64). Allowable Subject Matter Claims 2-11 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. Regarding claim 2, cited art(s) failed to teach, “performing power modulation mode switching of a dual-active-bridge-type micro-inverter, such that the power is bi-directionally transmitted from a DC side to an AC side and from the AC side to the DC side, thereby reducing an effective value of a secondary side current of a transformer comprises: determining an internal phase shift angle D1 and an external phase shift angle D2, the internal phase shift angle Di is an angle between a negative rising edge of a square wave voltage generated by a primary side square wave generating circuit and a positive rising edge of the square wave voltage generated by the primary side square wave generating circuit; the external phase shift angle D2 is an angle between a fundamental wave of the square wave voltage generated by the primary side square wave generating circuit of the transformer and a fundamental wave of a square wave voltage generated by a secondary side square wave generating circuit of the transformer; directly controlling the primary side square wave generating circuit by using the internal phase shift angle Di to generate a corresponding square wave voltage, controlling the secondary side square wave generating circuit by using the external phase shift angle D2 summed with an output of the current loop closed-loop control by an adder, to generate a corresponding square wave voltage, to realize the given transmission power of the micro-inverter; taking the internal phase shift angle D1 and the external phase shift angle D2 as two control degrees of freedom of the micro-inverter, according to the two control degrees of freedom of the micro-inverter, dividing the modulation mode of transmission power into mode one, mode two and mode three, and according to the instantaneous transmission power of the micro-inverter and the value of the internal phase shift angle D1, switching the micro-inverter between mode three and mode two”. Claims 3-11 are depending from claim 1. Claims 12-13 are allowed. Regarding independent claim 12, cited art(s) failed to teach, “a dual-active-bridge-type micro-inverter, comprises a dual-active-bridge-type micro-inverter body and a power modulation mode switching system; an input end of a phase-locked loop segment is connected to the power grid, an output end of the phase-locked loop segment, after combining with the output end of the power grid current given value, is connected to an input end of a current loop segment; the input end of the feed-forward control segment is connected to the DC side battery, the combination end of the phase-locked loop segment with the output end of the power grid current given value, and the power grid, respectively; one output end of the feed-forward control segment is connected to the primary side square wave generating circuit to control the primary side square wave generating circuit to output square wave voltage, and the other output end of the feed-forward control segment, after combining with the output end of the current loop segment, is connected to the secondary side square wave generating circuit, to control the secondary square wave generating circuit to output square wave voltage, thereby realizing a given transmission power; defining the angle between the negative rising edge of the square wave voltage generated by the primary side square wave generating circuit and the positive rising edge of the square wave voltage generated by the primary side square wave generating circuit as an internal phase shift angle Di; defining the angle between the fundamental wave of the square wave voltage generated by the primary side square wave generating circuit and the fundamental wave of the square wave voltage generated by the secondary side square wave generating circuit as an external phase shift angle D2; and taking the internal phase shift angle Di and the external phase shift angle D2 as two control degrees of freedom of the dual-active-bridge-type micro-inverter, according to the two control degrees of freedom, dividing the modulation mode of transmission power of the dual-active-bridge- type micro-inverter into mode one, mode two and mode three, and according to the instantaneous transmission power of the dual-active-bridge-type micro-inverter and the value of the internal phase shift angle D1, switching the micro-inverter between mode three and mode two”. Claims 13 is depending from claim 12. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to NUSRAT QUDDUS whose telephone number is (571)270-7921. The examiner can normally be reached on M-Th 9-4PM ET. 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, CRYSTAL L. HAMMOND can be reached at (571) 270-1682. 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. /NUSRAT QUDDUS/Examiner, Art Unit 2838 /CRYSTAL L HAMMOND/Supervisory Primary Examiner, Art Unit 2838
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Prosecution Timeline

Apr 22, 2024
Application Filed
Mar 18, 2026
Non-Final Rejection — §103 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
89%
Grant Probability
95%
With Interview (+5.9%)
2y 9m
Median Time to Grant
Low
PTA Risk
Based on 808 resolved cases by this examiner. Grant probability derived from career allow rate.

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