Prosecution Insights
Last updated: April 19, 2026
Application No. 18/932,185

GRID-FORMING INVERTER AND GRID-FORMING INVERTER SYSTEM FOR DISTRIBUTED POWER SOURCES BASED ON INTERMITTENT RENEWABLE ENERGY SOURCES AND CONTROL METHOD THEREOF

Non-Final OA §102§112
Filed
Oct 30, 2024
Examiner
KAPLAN, HAL IRA
Art Unit
2836
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Korea Institute Of Energy Research
OA Round
1 (Non-Final)
86%
Grant Probability
Favorable
1-2
OA Rounds
2y 9m
To Grant
95%
With Interview

Examiner Intelligence

Grants 86% — above average
86%
Career Allow Rate
756 granted / 879 resolved
+18.0% vs TC avg
Moderate +9% lift
Without
With
+9.1%
Interview Lift
resolved cases with interview
Typical timeline
2y 9m
Avg Prosecution
15 currently pending
Career history
894
Total Applications
across all art units

Statute-Specific Performance

§101
2.6%
-37.4% vs TC avg
§103
34.6%
-5.4% vs TC avg
§102
24.4%
-15.6% vs TC avg
§112
31.6%
-8.4% vs TC avg
Black line = Tech Center average estimate • Based on career data from 879 resolved cases

Office Action

§102 §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 . Priority Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55. Specification The disclosure is objected to because of the following informalities: Paragraph [0080], line 1, “frequency command valve” should be “frequency command value”. Paragraph [0120], line 6, “doop curve” should be “droop curve”. Appropriate correction is required. Drawings The drawings were received on October 30, 2014. These drawings are acceptable. 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. Claims 12-14 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. Claim 12 recites the limitation “the size of converted power is reduced”. It is unclear what is meant by the “size” of converted power. For examination purposes, it has been assumed that the amount of converted power is reduced in the droop mode. Claims 13-14 inherit this deficiency. Claim Rejections - 35 USC § 102 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 the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action: A person shall be entitled to a patent unless – (a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention. Claim(s) 1-5, 7, and 9 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by the international patent application of Ho et al. (WO 2021256850 A1). An English translation of Ho is attached. As to claim 1, Ho discloses a grid-forming inverter comprising: a power stage to convert electric power according to on/off controls of switching devices and to output the converted electric power to a grid (see Figures 1 and 2, grid connected inverter), and a control circuit to calculate a frequency command value in proportion to a direct current input voltage and to control the switching devices using pulse width modulation (PWM) according to the frequency command value (see paragraphs [0030], [0031], [0037], [0073], and Figures 5 and 6. The inverter operates proportionally based on incoming power from the solar panel (PV), the solar panel (PV) would generate power based on temperature and/or ambient conditions). As to claim 2, a capacitor is disposed in an input side of the power stage and the direct current input voltage is formed in the capacitor (see Figure 2). As to claim 3, the capacitor is a DC-link capacitor disposed between the input side of the power stage and a source-side converter (see solar panel (PV) coupled to a capacitor which is coupled to the inverter, Figures 1 and 2). As to claim 4, to the source-side converter, a renewable energy source, in which the generation output is changed depending on weather conditions, is connected (see solar panel (PV), which generates power based on sunlight). As to claim 5, between an output side of the power stage and a grid connection point, an output filter having a constant impedance is disposed (the inductors (Lf) and capacitors (Cf) after the inverter are filters, see Figure 2). As to claim 7, Ho teaches a grid-forming inverter control method, in which a grid-forming inverter controls a power stage to convert electric power according to on/off controls of switching devices and to output the converted electric power to a grid (see grid connected inverter, Figures 1 and 2); comprising: calculating frequency parameters including a frequency command value in proportion to a direct current input voltage; and controlling the switching devices using pulse width modulation (PWM) according to factors including the frequency command value (see paragraphs [0030], [0031], [0037], and [0073], and Figures 5-6; see element 130; the inverter operates proportionally based on incoming power from the solar panel, the solar panel would generate power based on temperature and/or ambient conditions). As to claim 9, between an input side of the power stage and a source-side converter, a DC-link capacitor is disposed (see Figure 2). Allowable Subject Matter Claims 11 and 15 allowed. Claims 6, 8, and 10 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. Claims 12-14 would be allowable if rewritten or amended to overcome the rejection(s) under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), 2nd paragraph, set forth in this Office action. The following is an examiner’s statement of reasons for allowance: Claims 11 and 15 are allowed, and claims 12-14 contain allowable subject matter, because none of the prior art of record discloses or suggests a grid-side converter to calculate a frequency command value in proportion to a voltage of the DC-link capacitor to convert electric power of the DC-link capacitor according to the frequency command value, and to output it to a grid, in combination with the remaining claimed features. Any comments considered necessary by applicant must be submitted no later than the payment of the issue fee and, to avoid processing delays, should preferably accompany the issue fee. Such submissions should be clearly labeled “Comments on Statement of Reasons for Allowance.” The following is a statement of reasons for the indication of allowable subject matter: Claim 6 contains allowable subject matter because none of the prior art of record discloses or suggests the control circuit calculating the frequency command value by multiplying a difference between the direct current input voltage and a reference direct current voltage by a proportional constant and adding a nominal frequency to a result value, in combination with the remaining claimed features. Claim 8 contains allowable subject matter because none of the prior art of record discloses or suggests calculating a voltage command value according to a difference between a value of reactive power of outputted power and a received reactive power command value, and the switching devices are controlled using PWM according to the frequency command value and the voltage command value in the step of controlling the switching devices using PWM, in combination with the remaining claimed features. Claim 10 contains allowable subject matter because none of the prior art of record discloses or suggests in the step of calculating the frequency command value, the frequency command value is calculated by multiplying a difference between the direct current input voltage and a reference direct current voltage by a proportional constant and adding a nominal frequency to a result value, in combination with the remaining claimed features. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to HAL KAPLAN whose telephone number is (571)272-8587. The examiner can normally be reached 9:30AM-5:00PM. 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, Rexford Barnie can be reached at 571-272-7492. 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. /HAL KAPLAN/Primary Examiner, Art Unit 2836
Read full office action

Prosecution Timeline

Oct 30, 2024
Application Filed
Jan 29, 2026
Non-Final Rejection — §102, §112 (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
86%
Grant Probability
95%
With Interview (+9.1%)
2y 9m
Median Time to Grant
Low
PTA Risk
Based on 879 resolved cases by this examiner. Grant probability derived from career allow rate.

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