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 information disclosure statements (IDS) submitted on 5 December 2024 and 23 May 2025 are in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statements are being considered by the examiner.
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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 1-2 and 11-13 are rejected under 35 U.S.C. 103 as being unpatentable over US 2015/0370278 by Li et al. (Li hereinafter) in view of “Adaptive Step Size With Adaptive-Perturbation-Frequency Digital MPPT Controller for a Single-Sensor Photovoltaic Solar System” by Jiang et al. (Jiang hereinafter).
Regarding claim 1, Li discloses a method comprising: calculating, based on a measurement of an output current level from a photovoltaic panel [see at least paragraph 0008, “sampling present voltage and present current of the photovoltaic array”], a power difference [see at least paragraph 0010, “using a difference between the present power and power for a previous sampling time”] between a present output power from the photovoltaic panel [see at least paragraph 0009, “obtaining present power based on the present voltage and the present current…”] and a previous output power [see at least paragraph 0010, “and power for previous sampling time”]; determining a voltage step corresponding to the power difference [see at least paragraph 0010, “obtaining present gradient perturbation voltage step ratio based on ratio of the present perturbation power to perturbation power for previous sampling time”]; and modifying the voltage of the photovoltaic panel, by the voltage step [see at least paragraphs 0011-0012, “controlling output voltage of the photovoltaic array based on the perturbation voltage step”].
Li fails to disclose determining, based on a correspondence of voltage steps to timesteps, a timestep corresponding to the voltage step; and modifying the voltage of the photovoltaic panel, by the voltage step, for a duration of the timestep. However, Jiang discloses an adaptive step size with adaptive perturbation frequency in a MPPT system [see at least Abstract] wherein a duty cycle step size (similar function to voltage step) is variable [see at least Table II] results in different adaptive perturbation time period [see at least page 3198, column 2, “Different step sizes ∆D result in different output voltage settling times that determine the adaptive perturbation time period”; Formula 15].
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the Applicant's invention to modify the variable step MPPT system of Li to include the adaptive perturbation timing in an MPPT system, as disclosed by Jiang, to improve performance including convergence speed and tracking efficiency over fixed duty cycle perturbation step size [see Jiang page 2201, column 1, “When the adaptive perturbation period scheme is activated…”]. Thus, creating a more reliable output, by reducing convergence speed, for attached devices and reducing the chance of damaging fluctuations.
Regarding claim 2, Li in view of Jiang teaches the method of claim 1.
Li discloses wherein the determining the voltage step is based on the power difference [see at least paragraph 0010, “obtaining present gradient perturbation voltage step ratio based on ratio of the present perturbation power to perturbation power for previous sampling time”] and a correspondence of power difference to voltage step [see at least paragraph 0079], and wherein the method further comprises determining the correspondence of power difference to voltage step [see at least below paragraph 0079,
Udc.sub.ref.sub.k+1=Udc.sub.ref.sub.k+ΔU.sub.k+1, if ΔP.sub.k×ΔU.sub.k>0;
Udc.sub.ref.sub.k+1=Udc.sub.ref.sub.k−ΔU.sub.k+1, if ΔP.sub.k×ΔU.sub.k<0].
Regarding claim 11, Li discloses an apparatus comprising: a power converter [see at least Figure 3, “inverter”] configured to convert power between first terminals [see at least Figure 3, left input into “inverter”] and second terminals [see at least Figure 3, right output out of “inverter”\, wherein the first terminals are for coupling to a photovoltaic panel [see at least Figure 3, left component non labeled; Abstract, “photovoltaic array”]; a sensor [see at least Figure 3, “sensor” between “photovoltaic” and “inverter”] configured to measure an output current level from the photovoltaic panels at the first terminals [see at least paragraph 0008, “sampling present voltage and present current of the photovoltaic array”]; and a controller [see at least Figure 3, “MPPT” and “double-loop close control”] configured to: calculate, based at least on the measurement of the output current level from a photovoltaic panel [see at least paragraph 0008, “sampling present voltage and present current of the photovoltaic array”], a power difference [see at least paragraph 0010, “using a difference between the present power and power for a previous sampling time”] between a present output power from the photovoltaic panel [see at least paragraph 0009, “obtaining present power based on the present voltage and the present current…”] and a previous output power [see at least paragraph 0010, “and power for previous sampling time”]; determine a voltage step corresponding to the power difference [see at least paragraph 0010, “obtaining present gradient perturbation voltage step ratio based on ratio of the present perturbation power to perturbation power for previous sampling time”]; and control the power converter to modify the voltage at the first terminals by the voltage step [see at least paragraphs 0011-0012, “controlling output voltage of the photovoltaic array based on the perturbation voltage step”].
Li fails to disclose determine a timestep corresponding to the voltage step; and control the power converter to modify the voltage at the first terminals by the voltage step for a duration of the timestep. However, Jiang discloses an adaptive step size with adaptive perturbation frequency in a MPPT system [see at least Abstract] wherein a duty cycle step size (similar function to voltage step) is variable [see at least Table II] results in different adaptive perturbation time period [see at least page 3198, column 2, “Different step sizes ∆D result in different output voltage settling times that determine the adaptive perturbation time period”; Formula 15].
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the Applicant's invention to modify the variable step MPPT system of Li to include the adaptive perturbation timing in an MPPT system, as disclosed by Jiang, to improve performance including convergence speed and tracking efficiency over fixed duty cycle perturbation step size [see Jiang page 2201, column 1, “When the adaptive perturbation period scheme is activated…”]. Thus, creating a more reliable output, by reducing convergence speed, for attached devices and reducing the chance of damaging fluctuations.
Regarding claim 12, Li in view of Jiang teaches the apparatus of claim 11.
Li discloses wherein the controller is further configured to determine the voltage step based on the power difference [see at least paragraph 0010, “obtaining present gradient perturbation voltage step ratio based on ratio of the present perturbation power to perturbation power for previous sampling time”] and a correspondence of power difference to voltage step [see at least paragraph 0079], and wherein the control is configured to determine the correspondence of power difference to voltage step [see at least below paragraph 0079, Udc.sub.ref.sub.k+1=Udc.sub.ref.sub.k+ΔU.sub.k+1, if ΔP.sub.k×ΔU.sub.k>0; Udc.sub.ref.sub.k+1=Udc.sub.ref.sub.k−ΔU.sub.k+1, if ΔP.sub.k×ΔU.sub.k<0].
Regarding claim 13, Li in view of Jiang teaches the apparatus of claim 11.
Jiang discloses wherein the controller is further configured to determine the correspondence of voltage steps to timesteps [see at least page 3198, column 2, “Different step sizes ∆D result in different output voltage settling times that determine the adaptive perturbation time period”; Formula 15].
Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over US 2015/0370278 by Li et al. (Li hereinafter) in view of “Adaptive Step Size With Adaptive-Perturbation-Frequency Digital MPPT Controller for a Single-Sensor Photovoltaic Solar System” by Jiang et al. (Jiang hereinafter) in further view of US 2020/0153336 by Mihai et al. (Mihai hereinafter).
Regarding claim 3, Li in view of Jiang teaches the method of claim 1.
Jiang discloses the correspondence of voltage steps to timesteps [see at least page 3198, column 2, “Different step sizes ∆D result in different output voltage settling times that determine the adaptive perturbation time period”; Formula 15].
Li in view of Jiang fails to teach further comprises determining, based on a current error difference, the correspondence of voltage steps to timesteps. However, Mihai discloses a photovoltaic system [see Figure 1; Abstract] which utilizes a current error signal as a factor in a control strategy for voltage output of a photovoltaic array [see at least paragraph 0097, “pre-charge current error signals” and “process current error signal”].
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the Applicant's invention to modify the MPPT photovoltaic system of Li in view of Jiang to factor current error signals, as disclosed by Mihai, including the difference of current error signals in order to more accurately determine a perturbation and reliably make adjustments to the control steps necessary to stabilize the output. Thus, creating a more reliable output for attached devices and reducing the chance of damaging fluctuations
Allowable Subject Matter
Claims 4-10 and 14-20 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.
The following is a statement of reasons for the indication of allowable subject matter: claims 4-10 and 14-20 are considered to contain allowable subject matter in light of the review of EPO OA dated 13 May 2025 which indicated allowable subject matter and further as the prior art, alone or in combination fails to disclose all of the limitations of claims 4 and 14: wherein, determining the correspondence of voltage step to timesteps comprises: determining, for a selected voltage step of a plurality of voltage steps, a current step response of an output current flowing from the photovoltaic panel; determining a convergence current level to which the output current, from the photovoltaic panel, converges over time; applying the voltage step a plurality of times, each time for a time-period of a plurality of time-periods; for each time-period, measuring a corresponding level of an output current flowing from the photovoltaic panel; determining, based on the corresponding level of the output current of each time-period, a current frequency response; identifying, from the current frequency response, a time-period with a corresponding level of the output current at in which a difference between the current corresponding to the time-period and the convergence current level, is equal or smaller than a current error difference; and setting the time-period as corresponding to the voltage step of claim 4 with similar language present in claim 14. Claims 5-10 and 15-20 are dependent on the above claims.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Wu (WO 2013/044580) discloses MPPT control system with self-adaptive control and step length.
Berroteran et al. (US 2021/0057915) discloses a dual-sampling MPPT control system with varying voltage steps.
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/JOEL BARNETT/Examiner, Art Unit 2849
/Menatoallah Youssef/SPE, Art Unit 2849