DETAILED ACTION
The instant action is in response to application 19 October 2023.
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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 7 May 2026 has been entered.
Specification
The specification has not been checked to the extent necessary to determine the presence of all possible minor errors. Applicant's cooperation is requested in correcting any errors of which applicant may become aware in the specification.
Priority
Acknowledgment is made of applicant's claim for priority based on a WIPO application filed in Italy on 20 April 2021.
Response to Arguments
Applicant’s responses to the merits have been considered but are not persuasive. Applicant argues, in particular, that “preventing desynchronization of the power converter relative to the power grid,” does not appear to be taught by the combination. While applicants’ invention does do this in a slightly different manner, the above limitation is extremely broad. Shui explicitly mentions fault ride through in Section 4 of his publication and discusses it at some length. Garcia also shows a fault ride through in Figure 1, and describes a number of ways to ride through a fault. Keeping a generator active definitely provides Watt support, and in most cases provides VAR support as well. Both of which prevents desynchronization. While applicant may have meant something different, the breadth of the limitation means that the prior art still reads on the subject.
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 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.
For method claims, note that under MPEP 2112.02, the principles of inherency, if a prior art device, in its normal and usual operation, would necessarily perform the method claimed, then the method claimed will be considered to be anticipated by the prior art device. When the prior art device is the same as a device described in the specification for carrying out the claimed method, it can be assumed the device will inherently perform the claimed process. In re King, 801 F.2d 1324, 231 USPQ 136 (Fed. Cir. 1986). Therefore the previous rejections based on the apparatus will not be repeated. (The claims have been condensed.)
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.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
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 of this title, 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 1-20 are rejected under 35 U.S.C. 103 as being unpatentable over Shuai et als “Transient Angle Stability of Virtual Synchronous Generators Using Lyapunov’s Direct Method” (IEEE NPL) in view of Garcia (US 20150137520).
As to claim 1, Shuai discloses a method of controlling a power converter (Fig. 1/2) to mimic a synchronous generator (title) “virtual synchronous generator”, wherein the method comprises:]determining a frequency control error (input kp) in dependence on at least a setpoint frequency (w0) and an actual frequency (w), determining an active power target (P*), determining a phase angle target (theta (output 1/s)),determining a voltage control error (input Dq) in dependence on at least a setpoint voltage (E0) and an actual voltage (E), determining a reactive power target (Q*), [[- ]]determining an output voltage target (Vd*), and controlling the power converter based on the output voltage target (Fig. 1, has phase and PWM inputs) and the phase angle target, wherein the method comprises preventing desynchronization of the power converter relative to the power grid, by at least one of reactive power target (Exc) otherwise (Fig. 2 B, shows Q error reading into the voltage calculation)..
Shuai does not disclose freezing the active power target (PSet) to remain constant in case a fault signal (SF) indicating a fault is detected, freezing the phase angle target (Ф) to remain constant in case a fault signal (SF) indicating a fault is detected, freezing the reactive power target (Exc) to remain constant in case a fault signal (SF) indicating a fault is detected, or freezing the output voltage target (Vd*) to remain constant in case a fault signal (SF).
Garcia teaches preventing desynchronization of the power converter relative to the power grid (Fig. 1), by freezing the active power target (PSet) to remain constant in case a fault signal (SF) indicating a fault is detected, freezing the phase angle target (Ф) to remain constant in case a fault signal (SF) indicating a fault is detected, freezing the reactive power target (Exc) to remain constant in case a fault signal (SF) indicating a fault is detected are frozen to the saved/pre-fault values, the WTGs are working in their local LVRT mode during the FREEZE-Q CTRL state.”), or freezing the output voltage target (Vd*) to remain constant in case a fault signal (SF) (See Fig. 5, specifying a freeze control state, and ¶8 “and at least that part of the central plant controller which provides control of electric production in the nominal-operation mode is frozen and a pre-fault-operation value of at least one control variable is stored.” describing how at least one individual control value shown in Fig. 4 corresponding to Pref (power), PFref (phase angle), Qref (reactive power), and Vref (votlage)).
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 device above to use the fault control of Garcia in the system above to provide low voltage ride through.
As to claim 2, Shuai in view of Garcia teaches wherein the method comprises determining [[a]]an initialization value of at least one of an actual active power (Pact) and an actual reactive power (Qact) of the power converter when the fault signal (SF) indicating a fault is detected (The value is frozen, so it must be stored from prefault data).
As to claim 3, Shuai in view of Garcia teaches wherein the method comprises continuously storing data in a memory in predetermined periods, wherein the data include at least one of the actual active power and the actual reactive power, and wherein determining the initialization value includes selecting the initialization value out of the data stored in the memory (The value is frozen, so it must be stored from prefault data)..
As to claim 4, Shuai in view of Garcia teaches wherein the method comprises determining that the fault is no longer detected, and determining the active power target using the initialization value of the actual active power (Shuai, Fig. 2a) and/or determining the reactive power target using the initialization value of the actual reactive power (Shuai, Fig. 2b).
As to claim 5, Shuai in view of Garcai teaches wherein the method comprises waiting for a predetermined time after detecting that the fault is no longer (Garcia, Fig. 5) detected before determining the active power target (PSet) using the initialization value of the actual active power (Shuai, Fig. 2) and/or determining the reactive power target using the initialization value of the actual reactive power (Shuai, Fig. 2).
As to claim 6, Shuai in view of Garcia teaches wherein the method is configured to mimic a synchronous generator (title Shuai).
As to claim 7, Shuai in view of Garcia teaches wherein, in case no fault signal indicating a fault is detected, determining the phase angle target in dependence on at least the active power target includes: determining an active power error in dependence on at least the active power target and an actual active power, and determining the phase angle target in dependence on at least the active power error (Shuai, Fig. 2).
As to claim 9, wherein, Shuai in view of Garcia teaches in case no fault signal (SF) indicating a fault is detected, determining the output voltage target in dependence on at least the reactive power target (Exc) includes: determining a reactive power error in dependence on at least the reactive power target and an actual reactive power and determining the output voltage target in dependence on at least the reactive power error (Shuai, Fig. 2).
As to claim 11, Shuai in view of Garcia teaches a control arrangement and -a power converter (Virtual synchronous generator) that is realized as a voltage-controlled voltage source converter, wherein the control arrangement (item generating gate signals) is configured to execute the method of controlling the power converter of claim 1.
As to claim 12, Shuai in view of Garcia teaches a non-transitory computer-readable medium having a computer program comprising instructions stored thereon, wherein the instructions, when executed by a processor, cause the processor to perform the method of controlling the power converter of claim 1 (Garcia, ¶109).
As to claims 13-20, these are similar to claims already rejected above and are obvious for similar reasons.
Conclusion
Examiner has cited particular column, paragraph, and line numbers in the references applied to the claims above for the convenience of the applicant. Although the specified citations are representative of the teachings of the art and are applied to specific limitations within the individual claim, other passages and figures may apply as well. It is respectfully requested from the applicant in preparing responses, to fully consider the references in their entirety as potentially teaching all or part of the claimed invention, as well as the context of the passage as taught by the prior art or disclosed by the Examiner. In the case of amending the claimed invention, Applicant is respectfully requested to indicate the portion(s) of the specification which dictate(s) the structure relied on for proper interpretation and also to verify and ascertain the metes and bounds of the claimed invention.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to PETER M NOVAK whose telephone number is (571)270-1375. The examiner can normally be reached on 9AM-5PM,Monday through Thursday, EST.
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/PETER M NOVAK/ Primary Examiner, Art Unit 2839
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