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 .
Information Disclosure Statement
The listing of references in the specification is not a proper information disclosure statement. 37 CFR 1.98(b) requires a list of all patents, publications, or other information submitted for consideration by the Office, and MPEP § 609.04(a) states, "the list may not be incorporated into the specification but must be submitted in a separate paper." Therefore, unless the references have been cited by the examiner on form PTO-892, they have not been considered.
Claim Objections
Claims 5-6, 15-16 objected to because of the following informalities:
Re claims 5-6, 15-16, respective last paragraphs, it is recommended the claims be amended to clarify: “ϕr is the estimate of the remanent flux in the transformer” since it appears the formulas are what is used to estimate the remanent flux or uses value from the estimate based on Applicant’s disclosure.
Appropriate correction is required.
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.
Claim(s) 1-4, 7-14, 17-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Chekavskyy (US2024/0275271) in view of Non-Patent Literature: “An Inrush Current Suppression Strategy for Fast Voltage Recovery”, hereinafter Li.
Re claim 1. Chekavskyy teaches a method for energizing a transformer (transformer <TR>) with inverter-based resources (IBRs) (see Chekavskyy: [0003], [0033-0034], Figs. 2a-b, 3, 5b; note it is implied power electronics converter <PEC> may be an inverter, but see also further obviousness below), the method comprising:
generating an estimate of a remanent flux (magnetic flux initial condition, part of estimated flux of flux estimator <E> and also part of modeled flux of <ACU>, see Chekavskyy: [0037], [0057-0058]) in the transformer using samples of the current of the inverter, a DC voltage of the inverter, and an inverter switching function (see Chekavskyy: [0044-0045], [0052], [0057-0058], [0089-0090], [0094], Figs. 2a-b regarding flux estimator <E> and <ACU> using primary current, voltage, and predicted/modeled effects of PEC voltage switching control to estimate flux ϕ and also generate reference magnetic flux ϕ* which include estimates of the initial/residual flux);
determining an initial voltage phase angle of the inverter based on the estimated remanent flux in the transformer; and
starting the inverter with the initial voltage phase angle of the inverter (see Chekavskyy: [0043-0049], [0052-0053], [0064-0068], [0071], [0076], [0089-0090], Figs. 2a-b, 5b, regarding determining adjustment to PEC voltage output, i.e. including effectively a determined adjusted initial angle, based on the combined flux adjustment). See Chekavskyy: [0003], [0033-0034], [0037], [0043-0049], [0052-0053], [0057-0058], [0064-0068], [0071], [0076], [0089-0090], Figs. 2a-b, 3, 5b.
Although Chekavskyy generally discloses use of a switching-cycle-based feedback loop to control the PEC, Chekavskyy does not explicitly disclose the feedback loop includes feedback control to regulate current to zero. Li, however, teaches that it is known in the art of inverter control limiting inrush current to a transformer for the control loop to be modified to regulate a current of an inverter of the transformer to zero via a switching-cycle-based direct current (DC) feedback loop with an input current of zero (see Li: pgs. 2-3, Figs. 1, 4 regarding adding a current control loop to voltage control loop with reference value of zero to bring inverter current/primary winding current DC current to zero and reduce inrush and saturation of the transformer). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the system of Chekavskyy to incorporate the teachings of Li by adding a current control loop as recited to the inverter voltage control for purposes of controlling average DC current to the transformer from the inverter is zero to reduce inrush and saturation of the transformer (see Li: pg. 3).
Re claim 2. Chekavskyy in view of Li teaches the method according to claim 1, wherein the transformer is energized in less than 100 milliseconds (ms) (see Chekavskyy: [0074], Fig. 5b regarding potential operation to start supplying transformer by PEC being on the scale of 30ms; additionally, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to select and optimize respective voltage and current ratings of components of the system such that it results in a system capable of energization in the recited timeframe since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233. See also MPEP: 2144.05, II).
Re claim 3-4. Chekavskyy in view of Li teaches the method according to claim 1, wherein an inrush current of the transformer during the energizing of the transformer is less than 10 milliamps (mA) and less than 0.1 mA (see Chekavskyy: [0033], [0065-0066], [0076], Fig. 5b regarding design of the system to minimize inrush and selection of k and allowed amount of flux depending on desired performance; it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to select and optimize respective voltage and current ratings of components of the system such that it results in a system having inrush current in the recited range since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233. See also MPEP: 2144.05, II; one of ordinary skill would find it obvious and desirable that depending on the power rating of the inverter and degree to which flux is limited to result in smaller corresponding inrush current values if desired or suited for the intended application).
Re claim 7. Chekavskyy in view of Li teaches the method according to claim 1, wherein the regulating of the current of the inverter comprises sampling the current of the inverter at each switching cycle and comparing the sampled inverter current with a reference value (see Li: pg. 3, Figs. 1, 4 regarding sampling and averaging inverter/primary winding current and comparing with reference).
Re claim 8. Chekavskyy in view of Li teaches the method according to claim 7, wherein, at each switching cycle, either a first device of the inverter or a second device of the inverter is switched, depending on whether the sampled inverter current is higher or lower than the reference value (see Li: pgs. 2-3, Figs. 1, 4 regarding sampling and averaging inverter/primary winding current and comparing with reference to control PWM switching of inverter with high side and low side transistors, i.e. generally switched depending on the correction voltage derived from current control).
Re claim 9. Chekavskyy in view of Li teaches the method according to claim 1, wherein the transformer is connected to a solar panel, a wind turbine, a fuel cell, and/or a battery (see Li: Fig. 1 regarding system generally able to function with a DC source/battery at inverter input; alternatively, Official Notice is hereby taken that it is well known in the art of transformer coupled inverter power supply systems for the inverter to receive power from known types of power sources such as solar panels, wind turbines, fuel cells, or batteries, and it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to implement the system of Chekavskyy in view of Li by having the inverter/PEC be supplied by one of the known power source types to predictably provide DC electric power that may then be inverted to supply to transformer and corresponding load/grid per user’s intended application).
Re claim 10. Chekavskyy in view of Li teaches the method according to claim 1, wherein the transformer is connected with a power plant, a microgrid, and/or a distributed generation grid (see Chekavskyy: [0042], Figs. 2a-b regarding transformer output able to be to the grid/distributed generation grid).
Re claim 11, the claim recites a system for energizing a transformer having essentially the same components operated in the same manner as recited in claim 1, and is therefore rejected by the same reasoning applied above. Although Chekavskyy in view of Li does not explicitly disclose implementation of the control systems as a processor executing instructions stored in machine-readable medium, Official Notice is hereby taken that it is very well known in the art of power converter control systems for control functions to be implemented via processor executing stored instructions as recited and it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to implement the control systems of Chekavskyy in view of Li in this manner for purposes of providing well-known, equivalent control means that predictably allow for automatic control of the system in the desired manner.
Re claims 12-14, 17-20, the further recited limitations essentially correspond to the limitations recited in claim 2-4, 7-10, and are therefore rejected by the same reasoning applied above.
Allowable Subject Matter
Claims 5-6, 15-16 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 and upon addressing the noted Objections.
The following is a statement of reasons for the indication of allowable subject matter:
Claim 5 would be allowable over the prior art of record because the prior art of record, taken alone or in combination, does not teach, suggest, or render obvious a method as recited in claim 1, and further “wherein the estimate of the remanent flux in the transformer is generated using Equations 5 as follows: [Equation 5] where Φ𝑟 is the remanent flux in the transformer, Ts is a time period, N1 is a number of turns of a first winding of the transformer, i1(n) is a current in the first winding of the transformer in a first sampling, i1(n+1) is the current in the first winding of the transformer in a second sampling, vt1(n) is a voltage of the inverter in the first sampling, and vt1(n+1) is the voltage of the inverter in the second sampling”. As discussed above, Chekavskyy and Li disclose methods for energizing a transformer, generally including techniques that will estimate remanent flux in the transformer. Other similar prior art such as Non-Patent Literature: “An inrush current mitigation approach of the output transformer for inverter” and other cited prior art of record also discloses other known ways to calculate remanent flux, but the cited prior art of record does not appear to teach or suggest calculating the remanent flux according to the recited formula and its corresponding variables/parameters. Claim 5, in light of Applicant’s Specification and Drawings, would therefore overcome the cited prior art of record.
Claim 6 would be allowable over the prior art of record because the prior art of record, taken alone or in combination, does not teach, suggest, or render obvious a method as recited in claim 1, and further “wherein the initial voltage phase angle of the inverter is determined using Equation 7 as follows: [Equation 7] where 𝜑0 is the initial voltage phase angle of the inverter, Φ𝑟 is the remanent flux in the transformer, N1 is a number of turns of a first winding of the transformer, 𝜔 is a frequency of the inverter, and vt1 is a voltage of the inverter”. As discussed above, Chekavskyy and Li disclose methods for energizing a transformer, generally including techniques that will adjust initial voltage phase angle generally based on estimated remanent flux in the transformer. Other similar prior art such as Non-Patent Literature: “An inrush current mitigation approach of the output transformer for inverter” and other cited prior art of record also discloses other known ways to determine initial voltage phase angle of inverter to offset the remanent flux, but the cited prior art of record does not appear to teach or suggest calculating the remanent flux according to the recited formula and its corresponding variables/parameters. Claim 6, in light of Applicant’s Specification and Drawings, would therefore overcome the cited prior art of record.
Re Claims 15-16, the further recited limitations essentially correspond to the limitations recited in claim 5-6, and would therefore overcome the cited prior art of record by the same reasoning applied above.
Conclusion
In summary, it is recommended provide IDS with any references that are desired to be made of record and considered, consider the similar cited prior art of record, and consider the indicated allowable subject matter. Applicant is generally advised that claim language is given broadest reasonable interpretation, and to ensure that the claims sufficiently and clearly recite details of the manner in which the control is implemented, such as specific way that the remanent flux is estimated or the initial voltage phase angle is determined in the indicated allowable subject matter, in order to distinguish from similar prior art of record which may broadly function similarly. Applicant should provide specific explanation as to how any claimed features overcome the cited prior art of record to help clarify the record as appropriate.
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Non-Patent Literature: “An inrush current mitigation approach of the output transformer for inverter” discloses a transformer inrush mitigation system which controls inverter starting phase angle to offset residual flux in the transformer.
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/DAVID A SHIAO/Examiner, Art Unit 2836
/REXFORD N BARNIE/Supervisory Patent Examiner, Art Unit 2836
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