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 .
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) 1-20 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by DECOCK et al. EP3694099A1.
CLAIM 1
DECOCK et al. discloses a method for operating a plurality of inverter-based resources connected to an electrical grid at a point of common coupling (FIG.1, common output phase terminals 43,45,47), the method comprising:
providing pulse patterns (FIG. 2, 79,81 for at least two of the plurality of inverter-based resources to respective local controllers of the at least two of the plurality of inverter- based resources;
receiving, via the respective local controllers, one or more measured electrical signals from the electrical grid ;
establishing, via the respective local controllers, a timing reference for interleaving the pulse patterns for the at least two of the plurality of inverter-based resources based on the one or more measured electrical signals from the electrical grid (The grid voltage source 62 has a reference current for phase "a" that is i.sub.a, although one or more phases of the grid voltage source 62 can be used as reference phases.); and
operating the at least two of the plurality of inverter-based resources in parallel on the electrical grid via the respective local controllers utilizing the pulse patterns and the timing reference such that the pulse patterns are interleaved with each other to reduce a voltage distortion at the point of common coupling.
The aggregate phase output at the junction of the inverter common output phase terminals (42, 44, 46) and the grid phase terminals (43, 45, 47) is associated with current ripple and harmonic content that can be reduced or ameliorated by the system and method for frequency adjustment of the parallel inverters. As illustrated in FIG. 1, i.sub.a1 and i.sub.a2 are the inverter phase output currents of phase "a", and i.sub.a is the sum of i.sub.a1 and i.sub.a2 of the parallel inverters for a given phase. The ripple frequency of i.sub.a is two times that of i.sub.a1 and i.sub.a2; the ripple amplitude of i.sub.a is reduced by maintain a phase offset in one of PWM carriers by 180 degrees. The grid voltage source 62 has a reference current for phase "a" that is i.sub.a, although one or more phases of the grid voltage source 62 can be used as reference phases.
CLAIM 2
DECOCK et al. discloses the method of claim 1, wherein providing the pulse patterns for the at least two of the plurality of inverter-based resources further comprises:
determining the pulse patterns for the at least two of the plurality of inverter- based resources based on one or more selected harmonics comprising a combination of a magnitude and a phase angle with respect to a fundamental-frequency voltage such that a net effect of the one or more selected harmonics cancel each other when the at least two of the plurality of inverter-based resources are operating on the electrical grid (Figs. 2,3).
CLAIM 3
DECOCK et al. discloses the method of claim 2, wherein the pulse patterns comprises a first pulse pattern having a first amplitude of a selected harmonic and a second pulse pattern having a second amplitude of the selected harmonic, wherein the first and second amplitudes of the selected harmonic are equal.
Fig. 2, PWM 70 equal to PWM 81.
First, an upper graph 200 comprises first pulse-width-modulation carrier signal 79 superimposed on a second pulse-width-modulation carrier signal 81 of a first inverter 23 and the second inverter 123, respectively. The first pulse-width-modulation carrier signal 79 is generally one-hundred and eighty degrees offset (e.g., fixed phase offset that varies based on the number of parallel-coupled inverters) in phase from the second pulse width modulation carrier signal 81, consistent with two inverters (23, 123) coupled in parallel. Further, the relationship of the one-hundred and eighty-degree (180) phase offset may be maintained even if the data processor 68 adjusts the carrier frequency of the first pulse-width-modulation signal 79 and/or carrier frequency of the second pulse-width-modulation signal 81 to align with the reference signal (e.g., V.sub.an) provided by the grid voltage source 62. In general, the fixed phase offset of the output phases of the phase each parallel-coupled inverter is three-hundred and sixty degrees divided by the number (N) of parallel-coupled inverters or 360/N, which equals 180 degrees for two inverters in parallel. Accordingly, if the number of inverters in parallel is increased, the phase offset is determined by the equation 360/N, where N is the number of inverters in parallel.
CLAIM 4
DECOCK et al. discloses the method of claim 3, wherein the first pulse pattern has a first phase angle and the second pulse pattern has a second phase angle, the first phase angle being shifted from the second phase angle by 180 degrees (Fig. 2, PWM 81 shifted 180 deg. from PWM 79).
CLAIM 5
DECOCK et al. discloses the method of claim 1, wherein operating the at least two of the plurality of inverter-based resources in parallel on the electrical grid further comprises utilizing synchronous gating (Fig. 3, 308 grid voltage, inverter based resources 310,312).
CLAIM 6
DECOCK et al. discloses the method of claim 1, wherein operating the at least two of the plurality of inverter-based resources in parallel on the electrical grid further comprises utilizing pulse width modulation (PWM 310,312).
CLAIM 7
DECOCK et al. discloses the method of claim 1, further comprising: predetermining the pulse patterns for the at least two of the plurality of inverter-based resources offline; and storing the pulse patterns for the at least two of the plurality of inverter-based resources in the respective local controllers of the at least two of the plurality of inverter-based resources.
Under a fifth technique, the above frequency adjustments (e.g., for any of the first through the fourth techniques, inclusive) are stored in a look-up table, chart, an inverted file or data structure as frequency adjustment ratio multipliers and corresponding phase differences between the target phase difference and the observed phase difference. For example, the data structure may store calculations or determination of frequency adjustments in accordance with the equations for different ranges of observations of, ΔP, the observed phase difference; ΔP.sub.desired, the target phase difference; and/or δ.sub.1, the first composite phase difference; and δ.sub.2, the second composite phase difference.
CLAIM 8
DECOCK et al. discloses the method of claim 1, wherein the respective local controllers operate independently of each other to establish the timing reference for interleaving the pulse patterns and utilize only the one or more measured electrical signals without communicating to each other (Fig. 2, PWM carrier 70 is not communicating with PWM carrier 81).
CLAIM 9
DECOCK et al. discloses the method of claim 1,
wherein one or more of the plurality of inverter-based resources are wind turbines is considered an intended use for the inverter based system.
It has been held that recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from prior art apparatus satisfying the claimed structural limitations. Ex Parte Masham, 2 USPQ F. 2d 1647 (1987).
CLAIM 10
DECOCK et al. discloses receiving one or more measured electrical signals from the electrical grid; establishing a timing reference for interleaving the pulse patterns for the at least two of the wind turbines based on the one or more measured electrical signals from the electrical grid; and operating the at least two of the wind turbines in parallel on the electrical grid utilizing the pulse patterns and the timing reference such that the pulse patterns are interleaved with each other to reduce a voltage distortion at the point of common coupling (CLAIM 1 REJECTION).
The following recitation is consider an intended use for the invention; A wind farm connected to an electrical grid, comprising: a plurality of wind turbines connected in parallel to the electrical grid at a point of common coupling; a plurality of local controllers, each of the plurality of wind turbines being controlled by one of the plurality of local controllers, each of the plurality of local controllers comprising a pulse pattern programmed therein, the plurality of local controllers configured to perform one or more operations, the one or more operations comprising:
CLAIM 11
DECOCK et al. discloses, In certain prior art, two or more inverters are coupled to an alternating current grid power source by using a phase offset or interleaving angle between the inverters. However, variations in the phase of the grid power source tends to increase harmonic content and current ripple (e.g., in the aggregate alternating current output phase signals) even if the inverters operate with precise and stable phase outputs. Thus, there is need to compensate or adjust the carrier frequency of the pulse-width-modulation signal of one or more inverters to reduce or ameliorate harmonic content and phase ripple associated with the junction of the inverters to the alternating current grid power source.
The recitation with respect to windfarms is consider an intended use for the invention. It has been held that in the manner in which the claimed invention is employed is an intended use for the invention.
CLAIM 12
DECOCK et al. discloses a method for operating a plurality of inverter-based resources connected to an electrical grid at a point of common coupling, the method comprising: determining a pulse pattern for each of the plurality of inverter-based resources; receiving, via respective local controllers of the plurality of inverter-based resources, one or more measured voltage signals from the electrical grid; establishing, via the respective local controllers, a timing reference for interleaving the pulse patterns for the plurality of inverter-based resources based on the one or more measured voltage signals; and operating, via the respective local controllers, the plurality of inverter-based resources in parallel on the electrical grid utilizing the pulse patterns and the timing reference such that pairs of the pulse patterns of the plurality of inverter-based resources are interleaved together to reduce a voltage distortion at the point of common coupling (claim 1 rejection).
CLAIM 13
DECOCK et al. discloses the method of claim 12, wherein determining the pulse pattern for each of the plurality of inverter-based resources further comprises: determining the pulse pattern for each of the plurality of inverter-based resources based on one or more selected harmonics comprising a combination of a magnitude and a phase angle with respect to a fundamental-frequency voltage such that a net effect of the one or more selected harmonics cancel each other when the at least two of the plurality of inverter-based resources are operating on the electrical grid (claim 2 rejection).
CLAIM 14
DECOCK et al. discloses the method of claim 13, wherein an amplitude of the pairs of the pulse patterns are equal (Fig. 2, PWM carrier 79, PWM carrier 81).
CLAIM 15
DECOCK et al. discloses the method of claim 14, wherein a phase angle of the pairs of the pulse patterns shifted from each other as a function of a number of the plurality of inverter-based resources.
First, an upper graph 200 comprises first pulse-width-modulation carrier signal 79 superimposed on a second pulse-width-modulation carrier signal 81 of a first inverter 23 and the second inverter 123, respectively. The first pulse-width-modulation carrier signal 79 is generally one-hundred and eighty degrees offset (e.g., fixed phase offset that varies based on the number of parallel-coupled inverters) in phase from the second pulse width modulation carrier signal 81, consistent with two inverters (23, 123) coupled in parallel. Further, the relationship of the one-hundred and eighty-degree (180) phase offset may be maintained even if the data processor 68 adjusts the carrier frequency of the first pulse-width-modulation signal 79 and/or carrier frequency of the second pulse-width-modulation signal 81 to align with the reference signal (e.g., V.sub.an) provided by the grid voltage source 62. In general, the fixed phase offset of the output phases of the phase each parallel-coupled inverter is three-hundred and sixty degrees divided by the number (N) of parallel-coupled inverters or 360/N, which equals 180 degrees for two inverters in parallel. Accordingly, if the number of inverters in parallel is increased, the phase offset is determined by the equation 360/N, where N is the number of inverters in parallel.
CLAIM 16
DECOCK et al. discloses the method of claim 12, wherein determining the pulse patterns for each of the plurality of inverter-based resources further comprises: predetermining the pulse patterns for each of the plurality of inverter-based resources offline (Fig. 2 presents PWM for each inverter-based resource, 79,81).
Claims 17,18
DECOCK et al. discloses the method of claim 12, wherein operating the at least two of the
plurality of inverter-based resources in parallel on the electrical grid further comprises
utilizing synchronous gating (fig. 3, grid voltage 308 in synchronized with PWM carriers 310,312).
CLAIM 19
DECOCK et al. discloses the method of claim 12, wherein the respective local controllers operate independently of each other to establish the timing reference for interleaving the pulse patterns and utilize only the one or more measured electrical signals without communicating to each other (Fig. 3, no communication channels).
CLAIM 20
DECOCK et al. discloses the method of claim 12,
wherein one or more of the plurality of inverter-based resources are wind turbines ( intended use, no patentable weight given to claim).
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ROBERT L DEBERADINIS whose telephone number is (571)272-2049. The examiner can normally be reached 9 am to 6 pm.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Barnie Rexford can be reached at 571 272 2391. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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September 2, 2026
/ROBERT L DEBERADINIS/Primary Examiner, Art Unit 2836
