DETAILED ACTION
This Office action is in response to the amendment filed on 22 October 2025.
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 .
Response to Arguments
Applicant's arguments filed 22 October 2025 have been considered but are moot because the new ground of rejection does not rely on the reference (Tsuchiya – see citation below) applied in the prior rejection of record as teaching the newly-recited features of, “a plurality of power converters” being “arranged in parallel with each other so that each power converter from the plurality of power converters independently transfer power to feed the external DC load,” as recited in amended claim 1, and similarly recited in amended claim 11.
However, to the extent that the filed remarks are understood to apply in a more general sense to claim construction and the teachings of the cited prior art, Examiner offers the following comments:
Applicant describes Tsuchiya as disclosing, “an arrangement intended for balancing voltages between multiple PV panels in low-voltage, residential or small-scale renewable systems. The goal of this configuration is equalization of individual PV module output and maintaining voltage balance along a series string” (Remarks, bottom p. 9). Applicant contrasts this with the “industrial” arrangement of the claimed inventions, noting that Tsuchiya lacks the suggestion of “high-capacity converters” for supplying “multi-megawatt DC industrial loads” (Remarks, top p. 10).
On one hand, Examiner respectfully disagrees with the characterization of Tsuchiya’s disclosed arrangement as being necessarily limited to residential or small-scale applications. While Tsuchiya discloses an example at [0019] of the arrangement being installed in a “general household”, the disclosure is not limited to this one example. Paragraph [0019] also describes its use in a “demand facility including a business establishment” that may further include a “power system … provided by a private power plant”. Similarly, at paragraph [0113] Tsuchiya describes further embodiments of the disclosed system which may include additional power generation facilities including wind power and hydroelectric power generation. As such, it is respectfully submitted that Tsuchiya’s arrangement is compatible with an industrial DC-DC power conversion system, and is thus considered to fall under the broadest reasonable scope of the preamble of the claims, as amended.
Second, it must be noted that in several places in the filed Remarks, Applicant distinguishes the invention from the disclosure of Tsuchiya by pointing to certain features that are not present in the claims as filed. In addition to the references, cited above, to “high-capacity converters” that supply “multi-megawatt” loads, Applicant further asserts (Remarks at p. 12) features of the invention including that the converters operate, “with maximum current greater than 10,000 Ampere … to feed the load of 20 MW or above as needed”, thus enabling “scalability, hot-swapping, and uninterrupted fail-safe operation”. Applicant argues that such features “categorically distinguish” the claimed invention from Tsuchiya’s arrangement. However, Examiner respectfully disagrees because only the limitations that are recited in the claims can serve to distinguish over the prior art. Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993).
Finally, it is noted that while the filed amendments are sufficient to overcome the previous rejection under 35 U.S.C. 112(b) for indefiniteness, they nonetheless raise a new issue as to the claims’ scope. Therefore, a new ground of rejection under section 112(b) is made in this Office action, necessitated by Applicant’s amendments.
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 2-10 and 12 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.
Applicant has amended the independent claims 1 and 11, which formerly recited details of a single power converter/power conversion system, by further specifying that the system or method includes a plurality of the power converters, each of which comprises the structural features and functional operations as were recited in the original claim set.
For example, claim 1 recites, at lines 3-4, “a plurality of power converters, each power converter from the plurality of power converters comprising,” which is followed with the limitations of claim 1 as originally filed.
As such, the dependent claims 2-10 and 12, which were formerly understood to further define the single instance of the power converter as originally claimed, are now indefinite in scope because it is not clear if they are limiting the claimed system by further defining just one of the plurality of converters, or if they are intended to further limit each of the plurality of power converters that are now required in the claimed system and method.
For examination purposes, these claims have been interpreted as further limiting each of the plurality of power converters set forth in their respective parent claim.
It is noted that the limitation recited in claim 10 further defines the power conversion system as a whole, and could be considered definite except that it depends from claim 5, which is indefinite for the reasons explained above. As such, the 112(b) rejection, specifically and exclusively as far it is directed to claim 10, could be overcome by amending it to depend directly from the independent claim.
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.
Claims 1-12 are rejected under 35 U.S.C. 103 as being unpatentable over Tsuchiya (US 2021/0218339) in view of “DC Connected Modular Power Converter System for Microgrids” by Grass et al. (hereinafter “Grass”).
In re claim 1, Tsuchiya discloses an industrial DC-to-DC power conversion system for a grid (Fig. 1; see grid connection 10) comprising:
at least one renewable energy-based first input source (30/SB) to provide a first DC input (voltage across terminals S, G);
a rechargeable Bi-directional energy storage device (40/41) adapted to provide an auxiliary DC input (voltage across terminals B, G);
a switching module (63, 64) in electrical communication with each of the renewable energy-based first input source and the rechargeable Bi-directional energy storage device to receive the first DC input and the auxiliary DC input respectively (switching circuits 63, 64 receive the voltages across S, G and B, G as shown in Fig. 1), and provide a switching module DC output (voltage across nodes 60a, G),
a boost module (62) in electrical communication with the switching module DC output (boost circuit 62 receives the voltage across 60a, G as shown), the boost module having a control circuitry (including at least switches 62a-e); and
wherein the control circuitry comprises a plurality of switching elements (62a-e) arranged in series or parallel (for example, switch 62a is in series with switch 62b);
each of the plurality of switching elements (in this case, 62a and 62b) is adapted to be controlled individually and independently of one another (by their respective base terminals), and each of the plurality of switching elements includes IGBT power modules components/devices (see [0025], and noting that the switches 62a, 62b are later referred to in the same manner as “SW elements”);
a control module (61) for controlling each of the switching module (63, 64) and the boost module (62), wherein the control module being adapted to operate the switching module to selectively enable charging of the rechargeable Bi-directional energy storage device from the renewable energy-based first DC input (see Fig. 3 and [0069]: mode 3, power is transferred from the first DC input SB to the battery BATT; see also [0067]: “the controller 61 controls the multiple DCCs 62, 63, and 64 so as to supply the generated power of the solar cell 30 to the storage battery 40 and charge the storage battery 40.”), and wherein the control module being adapted to control the boost module based on the magnitude of first DC input from the renewable energy-based first input source, to selectively operate the plurality of switching elements and provide an output therefrom acting as an input to an external DC load ([0067]: “When the generated power of the solar cell 30 is at an available level, the controller 61 controls the multiple DCCs 62, 63, and 64 so as to supply the generated power of the solar cell 30 to the DC load 20.”).
Tsuchiya discloses the claimed invention as described above, except for a plurality of such power converters, each of the power converters being arranged in parallel with each other so that each power converter independently transfers power to feed the external DC load.
However, the parallel operation of multiple power conversion modules of similar configuration was well-known in the field of power electronics converters and conventionally used for purposes such as combining the power outputs from multiple power sources and for increasing system load capacity. Such conventional knowledge is demonstrated by Grass, which discloses a power system including a plurality of modular DC-DC power converters (Fig. 1: “DC rack” and “further DC racks” as shown) connected in parallel via a DC bus (Abstract, Fig. 1) and configured to independently convert and transfer power between renewable-based sources (Fig. 1: wind turbine, PV generator, etc.), energy storage devices (Fig. 1: HV Li battery) and one or more DC loads (examples shown in Fig. 1; see p. 384, left column, fourth paragraph: “each power system can be operated as uninterruptible power supply for the internal DC grid”; see also pp. 384-385: sections “D. Stationary Battery Storage” and “E. DC power consumption”). Grass teaches that the modular, parallel system of power converters provides flexibility in combining different power sources, in power adaption through parallel operation (understood as increased load capacities), and optimization of energy supply for industrial, data processing, and other systems (see sec. “I. Introduction” on p. 383: list of bullet points bridging left and right columns).
Therefore 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 the system of Tsuchiya according to the teachings in Grass, by expanding the system to include a plurality of the power converters as disclosed in Tsuchiya and arranging the plurality of power converters in parallel with each other so that each power converter independently transfers power to feed the external DC load. Based on Grass’ disclosure as cited above, the person of ordinary skill would have been motivated to make the modification in order to obtain any of the various, known advantages, such as increased load capacity of the system.
In re claim 2, Tsuchiya discloses a measurement module (Fig. 1: 63n, 63k, 63h, 64h, 62h) adapted to continuously measure the magnitude of the first DC input (voltage from S, G: [0046], [0047]), and the switching module DC output (see [0068], [0076]), the measurement module being in communication with the control module ([0028]).
In re claim 3, Tsuchiya discloses wherein when the magnitude of the first DC input (voltage across S, G) is measured to be in a first input range, the control module (61) operates the switching module (63, 64) such that all of the first DC input is passed to the boost module (62) as the switching module DC output (see Fig. 3 and [0067], [0069]: mode 2, power is transferred from SB to DCLD via boost module 62).
In re claim 4, Tsuchiya discloses wherein when the magnitude of the first DC input (S, G) is measured to be in a second input range, the control module (61) operates the switching module (63, 64) such that all of the first DC input and the auxiliary DC input (voltage B, G) is passed to the boost module (62) as the switching module DC output (see Fig. 3 and [0067], [0069]: mode 5, power is transferred from both SB and BATT to DCLD via boost module 62).
In re claim 5, Tsuchiya discloses wherein when the magnitude of the first DC input (S, G) is measured to be in a third input range, the control module (61) operates the switching module (63, 64) such that a first portion of the first DC input is passed to the boost module (62) as the switching module DC output and a second portion of the first DC input is passed to the rechargeable Bi-directional energy storage batteries /device (see Fig. 3 and [0067], [0069]: mode 4, power is transferred from SB to both BATT and DCLD).
In re claim 6, Tsuchiya discloses wherein based on the value of the switching module DC output (60a), the switching elements of the boost module (62) are operated such that the output therefrom is at least at a threshold value required by the external DC load (see [0077]-[0084]: control is carried out according to the disclosed logic in order to prevent the “situation … in which the voltage of the DC load 20 drops and falls below the minimum operating voltage”).
In re claim 7, Tsuchiya discloses wherein when the value of the switching module DC output (60) is measured to being a first output range, all of the switching elements of the plurality of switching elements are closed whereby all of the switching module DC output (node 60a) is boosted to reach at least at a threshold value required by the external DC load (that is, the switches are PWM controlled to boost the voltage; see Fig. 3: mode 2; see [0077]-[0084] with explanation above and see [0056]).
In re claim 8, Tsuchiya discloses wherein when the value of the switching module DC output is measured to be in a second output range, a set of switching elements are opened whereby a portion of the switching module DC output (node 60a) is boosted to reach at least at a threshold value required by the external DC load (see Fig. 3: mode 4; see [0067] and [0069]).
In re claim 9, Tsuchiya discloses wherein the renewable energy-based first input source is one of solar and wind energy based (solar cell 30 in Fig, 1; see [0023]).
In re claim 10, Tsuchiya discloses wherein the external DC load (20) is a Hydrogen electrolyzer or any of the industrial, telecom or Data center loads (see [0021], in which the described water heater and/or its vapor compression pump as driven by the DC input to inverter 21 is considered to be an industrial load). In addition, resulting from the combination of Tsuchiya with Grass in the manner specified above with respect to claim 1, the system is further understood to be for use with other, similar loads as taught by Grass, including those associated with, “industrial production, data processing, mobility, and building technology” (see Grass, p. 383, 4th bullet point).
In re claim 11, Tsuchiya discloses a method of industrial DC-to-DC power conversion (as carried out by the circuitry shown in Fig. 1), the method comprising:
receiving a first DC input (from SB/30) from a renewable energy-based first input source (SB/30) based on generation of the first DC input from one of solar and wind energy (see [0023]);
receiving an auxiliary DC input (from BATT 41) from a rechargeable Bi-directional energy storage device (BATT 41) based on selectively charging of the rechargeable Bi-directional energy storage device from the renewable energy-based first DC input (see Fig. 3 and [0067], [0069]: mode 3, power is transferred from the first DC input SB to the battery BATT);
measuring values, via a measurement module (Fig. 1: 63n, 63k, 63h, 64h, 62h), of the first DC input (from SB 30), and the auxiliary DC input (from BATT 41);
passing one or more of the first DC input and the auxiliary DC input to a boost module (62), characterized in that based on the measurement of the magnitude of the first DC input, when the magnitude of the first DC input is measured to be in a first input range, operating a switching module to pass all of the first DC input to the boost module as the switching module DC output (see Fig. 3 and [0067], [0069]: mode 2, power is transferred from SB to DCLD via boost module 62),
when the magnitude of the first DC input is measured to be in a second input range, operating the switching module to pass all of the first DC input and the auxiliary DC input the boost module as the switching module DC output (see Fig. 3 and [0067], [0069]: mode 5, power is transferred from both SB and BATT to DCLD via boost module 62), and
when the magnitude of the first DC input is measured to be in a third input range, operating the switching module to pass a first portion of the first DC input to the boost module as the switching module DC output and passing a second portion of the first DC input to the rechargeable Bi-directional energy storage batteries /device (see Fig. 3 and [0067], [0069]: mode 4, power is transferred from SB to both BATT and DCLD),
the boost module having a plurality of switching elements (62a-e) arranged in series or parallel (for example, switch 62a is in series with switch 62b),
wherein each of the plurality of switching elements (62a-e) is adapted to be controlled individually and independently of one another (by their respective base terminals), and each of the plurality of switching elements includes IGBT power modules components/devices (see [0025], and noting that the switches 62a, 62b are later referred to in the same manner as “SW elements”); and in that,
operating the plurality of switching elements (62a-e), based on a threshold value required by an external DC load ( DC load 20 in Fig. 1; see [0077]-[0084]: control is carried out according to the disclosed logic in order to prevent the “situation … in which the voltage of the DC load 20 drops and falls below the minimum operating voltage”), to boost the one or more of the first DC input and the auxiliary DC input, passing there through (see Fig. 3 and [0067], [0069]: e.g., modes 1, 2, or 5); and
providing the threshold value to the external load (see [0077]-[0084] as explained above).
Tsuchiya discloses the claimed invention as described above, except for providing a plurality of such power converters, each of the power converters being arranged in parallel with each other so that each power converter independently transfers power to feed the external DC load.
However, the parallel operation of multiple power conversion modules of similar configuration was well-known in the field of power electronics converters and conventionally used for purposes such as combining the power outputs from multiple power sources and for increasing system load capacity. Such conventional knowledge is demonstrated by Grass, which discloses a power system including a plurality of modular DC-DC power converters (Fig. 1: “DC rack” and “further DC racks” as shown) connected in parallel via a DC bus (Abstract, Fig. 1) and configured to independently convert and transfer power between renewable-based sources (Fig. 1: wind turbine, PV generator, etc.), energy storage devices (Fig. 1: HV Li battery) and one or more DC loads (examples shown in Fig. 1; see p. 384, left column, fourth paragraph: “each power system can be operated as uninterruptible power supply for the internal DC grid”; see also pp. 384-385: sections “D. Stationary Battery Storage” and “E. DC power consumption”). Grass teaches that the modular, parallel system of power converters provides flexibility in combining different power sources, in power adaption through parallel operation (understood as increased load capacities), and optimization of energy supply for industrial, data processing, and other systems (see sec. “I. Introduction” on p. 383: list of bullet points bridging left and right columns).
Therefore 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 the method and its provided system of Tsuchiya according to the teachings in Grass, by further providing a plurality of the power converters as disclosed in Tsuchiya, and arranging the plurality of power converters in parallel with each other so that each power converter independently transfers power to feed the external DC load. Based on Grass’ disclosure as cited above, the person of ordinary skill would have been motivated to make the modification in order to obtain any of the various, known advantages, such as increased load capacity of the system and method.
In re claim 12, Tsuchiya discloses wherein the step of operating switching elements includes operating a set of switching elements of the plurality of switching elements (62a-e) periodically for a predetermined period of time (see [0056]), so that output therefrom is at least at a threshold value required by the external DC load (see [0077]-[0084] as explained above).
Additional Prior Art
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
US 2022/0231608, US 2024/0213781, US 2024/0322564 have each been cited because they show examples of modular power conversion systems configured to interconnect and transfer power between renewable-based energy sources, power storage elements/batteries. The disclosed systems are understood as being applicable at a variety of scales, for example up to multiple-megawatt industrial or data-center loads as taught in US 2024/0213781.
Conclusion
Applicant's amendment necessitated the new grounds of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/FRED E FINCH III/Primary Examiner, Art Unit 2838