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. Acknowledgment is made that the certified copies have been filed in English.
Claim Objections
Claims 1, 3-4, 6, 8-10, 13-14, 20 objected to because of the following informalities:
Re claims 1 and 13, Applicant is strongly advised that the claims as drafted may be interpreted very broadly under broadest reasonable interpretation to the extent that they could potentially raise issues under 35 USC 112 for encompassing a variety of DC-DC converter systems beyond what is reasonably disclosed as part of Applicant’s invention. As currently drafted, claims 1 and 13 provides insufficient detail as to the structure/manner of operation for adjusting the DC-link voltage, provides no limitation on what is considered an optimal value or value range for the ratio, and provides no limitation on what may be a desired current ripple level, the effect of which is that essentially almost any DC-DC converter system with battery and adjustable voltage DC link may arguably anticipate the recited limitations because it will inherently have some UES/UDC ratio that could be considered preferred/optimal for the disclosed system and inherently has some ripple level from operation of the DC-DC converter that may be considered acceptable for the disclosed system under broadest reasonable interpretation. The lack of structure/operation for achieving desired ripple level and control of DC link voltage may also potentially raise issues under 35 USC 112 for essentially only reciting the intended result of achieving optimal ratio and ripple without specifying the actual manner in which the system is operated to yield the intended result.
It is therefore recommended that at minimum Applicant amend the independent claims to provide at least the basic structure and operation of the system to actively monitor system parameters and adjust the DC link, and preferably also provide actual limitations on the specific manner of estimating corresponding ripple levels based on UES and manner of selecting UDC according to specific comparisons/limits/ideal values. Applicant should amend the claims to at minimum reflect the basic procedure shown in Applicant’s Fig. 10 (similar to claim 2) and basic structure similar to Fig. 11 for example (i.e. measuring current value of UES, calculating and selecting current optimal UDC value according to comparisons/limits/ideal values for predicted ripple, controlling the DC-DC converter or another converter coupled to the DC-link to dynamically adjust UDC to the current optimal UDC value). Preferably the claims should also provide further limitation of the specific manner of selecting the current optimal UDC according to algorithms disclosed in the Specification that would distinguish from prior art systems.
Re claims 3, 6, 9, which make reference to zero or zero points for ripple current, as drafted the claims do not provide sufficient context for when/why/how the ripple would ever be zero, and without further detail of the intended arrangement and values that are estimated to result in zero ripple current the claims may potentially raise clarity issues or be unintentionally broad. An examination of Applicant’s Specification appears to suggest that the actual control referred to is that for an N-phased converter, the ripple would theoretically be close to zero when the duty cycle is at a multiple of 1/N. Given that this appears to be the only disclosed control for achieving “zero” current ripple and that otherwise there appears to be no further way to identify such zero points, it is recommended that Applicant amend the claims to specify the actual required duty ratio being achieved to result in theoretically zero current ripple (i.e. such that ratio is controlled to M / N, where N is the number of interleaved phases of the DC-DC converter and 0 <= M <= N, or more limited range as appropriate). The claims may also specify for example that the ratio is controlled to be within a predetermined range of M/N or similar. Failure to provide sufficient context and definite limitation may raise issues under 35 USC 112.
Re claims 4, and last paragraph of claim 10, Applicant is advised that use of claim language such as “if” may render the limitations as merely optional. It is recommended that if the limitations are meant to be required that the corresponding required structure/arrangement of the system be recited together with explicit operation of how the system will operate “in response to” or “when” a corresponding condition is determined.
Re claim 8, the second line should correct the spelling: “interleaved”.
Re claim 14, as drafted the claim makes repeated introduction to “an AC power source” and “an AC load”, which is potentially confusing as to whether same or different elements are being referred to, and which is subsequently being referred to in claims 15 and 17. It is generally recommended that with respect to the DC link, there seems to be no difference between the recited “AC-DC converter” and a “DC-AC converter” with corresponding AC source and load, and that the claim may simply eliminate reference to the redundant DC-AC converter. The claim may otherwise be amended to ensure all separate elements are given distinct names and consistent reference is made to the names in the claim and its dependents.
Re claim 20, the last line and phrasing of the claim overall is grammatically confusing, and it is recommended the claim be more clearly rephrased: “wherein the controller comprises one or more of a separate controller unit…” if it is meant to describe that the controller includes one or more of the following controllers.
Appropriate correction is required.
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 3, 7-9 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.
Re claims 3, 9. A broad range or limitation together with a narrow range or limitation that falls within the broad range or limitation (in the same claim) may be considered indefinite if the resulting claim does not clearly set forth the metes and bounds of the patent protection desired. See MPEP § 2173.05(c). In the present instance, claims 3, 9 recite respective broad recitations followed by the claims respectively reciting limitations which “preferably” are present which is the narrower statement of the range/limitation. The claim(s) are considered indefinite because there is a question or doubt as to whether the feature introduced by such narrower language is (a) merely exemplary of the remainder of the claim, and therefore not required, or (b) a required feature of the claims. It is recommended that if Applicant intends for a further limitation to be required that they actually be recited as required and not only “preferably” present. The respective claims could be amended to recite the limitations as actually required, recited the limitations as optional/alternatives, move the narrower limitations to a dependent claim instead, or other appropriate amendment to address the indefiniteness issue. For purposes of examination, the claims will be interpreted as reciting the “preferable” limitations as merely optional until appropriate clarification is provided.
Re claims 3, 7, 8. The terms “close to” and “about” are relative terms which renders the claim indefinite. The terms are not specifically defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. Since it is generally understood in the field of electronics that control of values inherently has some margin of error, Applicant is advised that the claim language should generally not require such caveats such as “about” or “close to” unless the specific margin of error can be specifically defined. It is therefore recommended that claims 7-8 be amended to directly recite control to the corresponding values and for purposes of examination are interpreted accordingly. Claim 3 is recommended to be amended according to the suggestions above (see Objections regarding referencing zero or zero points in this application) and for purposes of examination are interpreted as optional limitations regardless as discussed above.
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) 1-9, 11-20 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Banhamhall (US2014/0347899).
Re claim 1. Banhamhall teaches a method (see Banhamhall: Figs. 2, 4), comprising
controlling a current ripple caused by a DC-DC converter (buck converter <1>) coupled between a DC-link (DC link <2>) and an energy storage (dc load/source <4> comprising battery, see Banhamhall: [0028], Fig. 2), the DC-link having a DC-link voltage UDC (dc link voltage <V1>) and the energy storage having a DC energy storage voltage UES (voltage <V2>; see Banhamhall: [0028-0032], Fig. 2 regarding arrangement of the system), wherein the controlling
dynamically adjusts the DC-link voltage UDC to control a ratio UES/UDC to an optimal value or value range that causes a desired current ripple level at the energy storage (see Banhamhall: [0018-0022], [0032], [0033-0036], Figs. 2, 4 regarding system controlling variable DC link voltage <V1> such that it corresponds to a ratio with <V2> that is a null point of the N-phase converter with theoretically zero ripple if possible, and otherwise sets the DC link voltage to minimum or maximum of its allowable range having lowest ripple). See Banhamhall: [0018-0022], [0028-0032], [0033-0036], [0039-0048], Figs. 2, 4. See also the Objection above regarding broadness of the claim language such that a large number of prior art references may arguably anticipate the limitations.
Re claim 2. Banhamhall teaches the method as claimed in claim 1, wherein the dynamically adjusting comprises determining a voltage or voltage range of the energy storage voltage UES, determining the optimal value or value range of the DC-link voltage UDC that gives the optimal value or value range of the ratio UES/UDC for the determined voltage or voltage range of the energy storage voltage UES, and adjusting the DC-link voltage UDC to the optimal value or value range to obtain the desired current ripple level for the determined voltage or voltage range of the energy storage voltage UES (see Banhamhall: [0019-0022], [0032], [0033-0036], Figs. 2, 4 regarding system determining <V2> and controlling variable DC link voltage <V1> based thereon such that it corresponds to a ratio that is a null point of the N-phase converter with minimal ripple if possible, and otherwise sets the DC link voltage to minimum or maximum of its allowable range yielding lowest ripple).
Re claim 3. As best understood, Banhamhall teaches the method as claimed in claim 1, wherein the desired current ripple is equal to or less than a predetermined target ripple or within a predetermined current ripple range, preferably a zero or close to zero (see Banhamhall: [0018-0022], [0032], [0033-0036], Figs. 2, 4 regarding control of <V1> such that the ratio is at a null point where ripple is theoretically zero or in practice close to zero; see also Objection above).
Re claim 4. Banhamhall teaches the method as claimed in claim 1, wherein the determining comprises selecting the highest possible optimal value or value range of the DC-link voltage UDC, if there is a plurality of possible optimal values or value ranges of the DC-link voltage UDC, to enable transferring as much electric power as possible (see Banhamhall: [0021], regarding selecting the highest DC link voltage/corresponding null point if multiple are within the allowable DC link voltage range; note also the Objection above regarding optional phrasing).
Re claim 5. Banhamhall teaches the method as claimed in claim 1, comprising discharging the DC-link before changing from one optimal value or value range of the DC-link voltage UDC to another (see Banhamhall: [0020-0022], [0031-0032], [0033-0036], [0043-0046], Figs. 2, 4 regarding bidirectional active rectifier/inverter <20> controlling DC link voltage and operation to drop DC-link voltage if provides improved ripple, i.e. will discharge the DC-link capacitor voltage).
Re claim 6. Banhamhall teaches the method as claimed in claim 1, wherein the DC-DC converter is an interleaved multi-phase DC-DC converter (see Banhamhall: [0028], Fig. 2 regarding N-phase interleaved bidirectional buck converter), and wherein the method comprises dynamically adjusting the DC-link voltage UDC to control the ratio UES/UDC to a value or value range that corresponds to one of zero points of current ripple (see Banhamhall: [0018-0022], [0032], [0033-0036], Figs. 2, 4 regarding control of <V1> such that the system is at a null point where ripple is theoretically zero or in practice close to zero; see also Objection above).
Re claim 7. As best understood Banhamhall teaches the method as claimed in claim 1, wherein the DC-DC converter is an interleaved three-phase DC-DC converter (see Banhamhall: [0028], Fig. 2 regarding N-phase interleaved bidirectional buck converter, i.e. includes N = 3), and wherein the method comprises adjusting the DC-link voltage to control the ratio UES/UDC to a value or value range that is about or close to one of 1/3, 2/3, and 1 (see Banhamhall: [0018-0022], [0032], [0033-0036], Figs. 2, 4 regarding control of <V1> such that the system is at a null point where ratio V2/V1 = a/N, e.g. 1/3 or 2/3 if N = 3, where ripple is theoretically zero or as close as possible in the allowable DC link voltage range).
Re claim 8. As best understood, Banhamhall teaches the method as claimed in claim 1, wherein the DC-DC converter is an intrleaved six-phase DC-DC converter (see Banhamhall: [0028], Fig. 2 regarding N-phase interleaved bidirectional buck converter, i.e. includes N = 6), and wherein the method comprises adjusting the DC-link voltage to control the ratio UES/UDC to a value or value range that is about or close to one of 1/6, 1/3, 1/2, 2/3, 5/6, 1 (see Banhamhall: [0018-0022], [0032], [0033-0036], Figs. 2, 4 regarding control of <V1> such that the system is at a null point where ratio V2/V1 = a/N, e.g. 1/6, 2/6, 3/6, 4/6, 5/6 if N = 6, where ripple is theoretically zero or as close as possible in the allowable DC link voltage range).
Re claim 9. As best understood Banhamhall teaches the method as claimed in claim 1, wherein the DC-DC converter is an interleaved multi-phase DC-DC converter, preferably and wherein the method comprises selectively switching off one or more phases of a multi-phase interleaved DC-DC converter to obtain a zero point of the current ripple at a desired point of the energy storage voltage range, preferably so that a phase shift between the remaining phases is 180 degrees or 90 degrees and there is a zero point of the current ripple at a midpoint of the energy storage voltage range (see rejection under 35 USC 112(b) regarding all of the limitations effectively recited as optional; Applicant is also generally advised that even if the limitations were given weight, prior art such as Nho, KR2018/0055266A and Maple, US2004/0070283 appears to teach it is known to design interleaved multi-phase DC-DC converters to be able to switch number of operating phases to operating to a 2 or 4 phase mode to allow for operation at null point corresponding to 0.5 duty cycle that is created when N = 2 or 4).
Re claim 11. Banhamhall teaches the method as claimed in claim 1, wherein the energy storage comprises one or more of a rechargeable energy storage, a hydrogen electrolyser, and a fuel cell (see Banhamhall: [0028], Fig. 2 regarding chargeable battery <4>).
Re claim 12. Banhamhall teaches the method as claimed in claim 1, wherein the DC-DC converter is bidirectional (see Banhamhall: [0028], Fig. 2 regarding bidirectional buck converter <1>).
Re claim 13. Banhamhall teaches an electric system (see Banhanhall: Fig. 2), comprising
a DC-link (DC link <2>), the DC-link having an adjustable DC-link voltage UDC (dc link voltage <V1>),
an energy storage (dc load/source <4> comprising battery, see Banhamhall: [0028], Fig. 2), the energy storage having a DC energy storage voltage UES (voltage <V2>),
a DC-DC converter (buck converter <1>) coupled between the DC-link and the energy storage (see Banhamhall: [0028-0032], Fig. 2 regarding arrangement of the system), and a
controller (controller <30>) controlling a current ripple caused by the DC-DC converter by dynamically adjusting the DC-link voltage UDC to control a ratio UES/UDC to an optimal value or value range that causes a desired current ripple level at the energy storage (see Banhamhall: [0018-0022], [0032], [0033-0036], Figs. 2, 4 regarding controller controlling rectifier/inverter <20> and variable DC link voltage <V1> such that it corresponds to a ratio with <V2> that is a null point of the N-phase converter with theoretically zero ripple if possible, and otherwise sets the DC link voltage to minimum or maximum of its allowable range having lowest ripple). See Banhamhall: [0018-0022], [0028-0032], [0033-0036], [0039-0048], Figs. 2, 4. See also the Objection above regarding broadness of the claim language such that a large number of prior art references may arguably anticipate the limitations.
Re claims 14-17. Banhamhall teaches the electric system as claimed in claim 13, comprising at least one further converter (active rectifier/inverter <20>) coupled to the DC-link coupled to a power source (AC grid <28>, see Banhamhall: [0031], Fig. 2) or a load, wherein the at least one further converter comprises one or more of an AC-DC converter (active rectifier/inverter <20>) connected to an AC power source (AC grid <28>, see Banhamhall: [0031], Fig. 2) or an AC load, a DC-AC converter connected to an AC power source or an AC load, and a further DC-DC converter connected to a DC power source or a DC load (all other options recited in the alternative); wherein the AC power source comprises one or more of an AC power grid (AC grid <28>, see Banhamhall: [0031], Fig. 2) and a wind power plant; wherein the DC power source comprises one or more of a battery, a fuel cell, and a solar power plant; wherein the load comprises an AC motor or a DC motor (all other options recited in the alternative).
Re claim 18. Banhamhall teaches the electric system as claimed in claim 13, comprising an adjustable voltage source (active rectifier/inverter <20>, see Banhamhall: [0031-0032], Fig. 2 regarding rectifier/inverter <20> allowing for adjusting of dc link voltage <V1>) of the adjustable DC-link voltage UDC.
Re claim 19. Banhamhall teaches the electric system as claimed in claim 14, wherein an adjustable voltage source of the adjustable DC-link voltage UDC comprises the DC-DC converter or the at least one further converter (active rectifier/inverter <20>, see Banhamhall: [0031-0032], Fig. 2 regarding rectifier/inverter <20> allowing for adjusting of dc link voltage <V1>; note also bidirectional buck converter <1> also generally will affect power/voltage to/from the dc link).
Re claim 20. Banhamhall teaches the electric system as claimed in claim 14, wherein the controller comprises a separate controller unit, a controller of the DC-DC converter or the at least one further converter, or a higher-level controller in the electric system, as any combination thereof (see Banhamhall: [0031-0032], Fig. 2 regarding controller <30> generally being separate or controller of rectifier/inverter <20>).
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.
Claim(s) 10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Banhamhall in view of Tsumura (US2016/0380575).
Re claim 10. Banhamhall teaches the method as claimed in claim 1, and further suggests wherein the DC-DC converter is a single-phase DC-DC converter (see Banhamhall: [0028], Fig. 2 regarding N-phase bidirectional buck converter, i.e. N may be 1), and the method comprises setting a limit value for the current ripple level of the energy storage (see Banhamhall: [0022], [0036], Figs. 2, 4 regarding changing between dc link voltage max and min values when the predicted ripple would be lower, i.e. there is inherently some limit value of the ripple current at which the dc link voltage change would occur based on the system’s established allowable dc link voltage <V1> range and the allowable battery voltage <V2> range; see also the behavior described in [0045]), determining a present current ripple level (see Banhamhall: [0022], [0036], [0045], Figs. 2, 4 regarding changing between dc link voltage max and min values when the predicted ripple would be lower, i.e. the system determines the corresponding ripple to determine which dc-link voltage provides better operating point), adjusting the DC-link voltage UDC primarily to a first predetermined value (see Banhamhall: [0022], [0036], Figs. 2, 4 regarding initially choosing max voltage of the allowable dc link voltage range), and adjusting the level of the DC-link voltage UDC from a first predetermined value to a second predetermined value (note limitation recited as optional; also see Banhamhall: [0022], [0036], Figs. 2, 4 regarding switching to minimum voltage of the allowable dc link voltage range when determined to produce lower ripple, i.e. below the limit value where would switch), if the present current ripple level was to exceed the limit value, wherein the second predetermined value is smaller than the first predetermined value, the second predetermined value controlling the ratio UES/UDC to a value or value range that limits the present current ripple level to the set limit value or less. Note that it is understood the control taught by Banhamhall will change between two DC-link voltage values with the lower voltage having lower ripple if the DC-link allowable maximum and minimum result in duty ratios that become farther/closer to null points based on the allowable range of the energy storage, and that Applicant’s disclosed embodiment also only will function in this manner given similar assumptions on the voltage ranges.
Although Banhamhall does not make explicit discussion of the single-phase embodiment and of explicit use of a limit value for the current ripple level, Tsumura further teaches that it is known in the art of power conversion systems regulating operation of a DC-DC converter to reduce ripple that use of single-phase DC-DC converters are known (see Tsumura: [0038], Fig. 1 regarding example single-phase boost converter <13>) and also that the change of operation point may be based on a set limit value for the ripple being potentially exceeded (see Tsumura: [0049], [0091], Figs. 1, 6, regarding estimation of ripple current and changing boost converter operation when exceeds ripple threshold). 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 Banhamhall in view of Tsumura by having the control method of Banhamhall applied to known single-phase DC-DC converter system as generally suggested by Banhamhall, and having the change of operating point being based on ripple limit value being exceeded as suggested by Tsumura for purposes of predictably and beneficially applying the DC link voltage control and ripple reduction technique of Banhamhall to single phase system even when the null value is not achievable due to the limits on the dc link voltage range (see Banhamhall: [0022], [0036]) and also to have the control be based on preferred ripple limits acceptable for the system (see Tsumura: [0049], [0091-0093] regarding ripple threshold determined based on amount acceptable for components of the power conversion system).
Conclusion
In summary, it is recommended Applicant amend the claims to address the noted Objections and 112 issues, and consider the cited prior art of record which appears to suggest that there are multiple DC-DC converter systems which reduce ripple by adjusting DC-DC link voltage to reach ratios where ripple is theoretically zero, or otherwise adjust the DC link voltage in its allowable range to values as close as possible to minimize ripple. At present it is not apparent what features of the invention would be considered distinguished and nonobvious over the prior art. If Applicant believes a specific embodiment and its operation would be inventive over the prior art, then it is recommended the claims be amended to specifically and clearly recite all required structure of the embodiment, and then the specific operation procedure of its controller to detect, calculate/determine, and control the variables of the system in a manner distinguished and nonobvious over the prior art. Applicant is reminded that claim language is given broadest reasonable interpretation during examination.
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Nho (KR2018/0055266A) and Morioka (US2005/0116695) also disclose DC-DC converters adjusting dc link voltage such that a duty cycle/ratio can be used which minimizes ripple. Maple (US2005/0116695) discloses interleaved DC-DC converter changing number of interleaved phases in operation to minimize ripple at a given duty cycle.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to DAVID A SHIAO whose telephone number is (571)270-7265. The examiner can normally be reached Mon-Fri: 8:30AM-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.
/DAVID A SHIAO/Examiner, Art Unit 2836
/REXFORD N BARNIE/Supervisory Patent Examiner, Art Unit 2836