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
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) 1-5, and 14-18 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Brogan et al. (U.S. Patent Publication Number 2020/0400120).
Regarding Claim 1:
Brogan et al. discloses a method of synchronized blackstart (see, at least, paragraphs 0003-0004, 0015-0025, 0064-0065, 0072-0073, etc.) in a power generating farm (Fig. 1, wind park 100) connected to an electrical grid (Fig. 1, grid 109), the method comprising: selecting, at least, a subset of a plurality of inverter-based resources at the power generating farm (Fig. 1, one of wind turbines 101a, 101b, 101c, etc., and their related discussion; see, at least, claim 1, “starting at least one first wind turbine…”) having grid forming capability (see, at least, claim 1, “… each being equipped with…a grid forming function…”) and an anchor power generating asset that are capable of contributing to the blackstart based on one more parameters (see, at least, claim 1, “…utilizing the respective grid independent energy supply for starting…” claim 14, “… wherein at least one of the grid independent energy supply… comprises at least one of: a Diesel and/or hydrogen powered generator; a solar cell system; an electric energy storage, in particular battery, accumulator, capacitor bank.” The anchor power generating asset read on by the respective grid independent energy supply comprising at least one of the assets as discussed), the plurality of inverter-based resources being connected to the electrical grid via a transmission network (Fig. 1, collector system 106 comprising cables 105 for connecting the plurality of wind turbines to grid 109 as shown, and their related discussion; see, at least, paragraph 0057); utilizing the grid forming capability of the subset of the plurality of inverter-based resources for initial start-up to bring the subset of the plurality of inverter-based resources online (see, at least, claim 1, “…starting at least one first wind turbine, each being equipped with an utility grid independent energy supply and a grid forming function, to produce electrical energy from wind energy, thereby utilizing the respective grid independent energy supply for starting; performing the grid forming function by the at least one first wind turbine to achieve a reference voltage in the collector system…”) and form a plurality of islands (see, at least, paragraphs 0080-0081, 0086-0088, claims 1, 3, etc. which disclose the start up method including connecting the first wind turbine, thereby forming a plurality of islands associated with the remaining wind turbines 101x), thereby partially re-energizing the transmission network and enabling restoration of one or more critical loads within a first time period during the blackstart (see, at least, claim 3, paragraphs 0069-0073, etc., which discloses “… allows them to supply the auxiliary loads (for example 167, 169, 171, 173, 175) for a given number of hours and pre-charge the main converter DC link 141…”); and during a subsequent, second time period, further energizing the transmission network to fully restore the electrical grid to normal operation (see, at least, claims 1, 3, etc. which disclose “starting at least one second wind turbine and/or at least one third wind turbine to produce energy by conversion of wind energy, thereby utilizing energy provided in the collector system for starting…”).
Regarding Claim 2:
Brogan teaches the limitations of the preceding claim 1. Brogan further discloses comprising identifying one or more local loads for the subset of the plurality of inverter-based resources (see, at least, claim 3, paragraphs 0069-0073, etc., which discloses “… allows them to supply the auxiliary loads (for example 167, 169, 171, 173, 175)…”), the one or more local loads comprising at least one of a block load connection capability, controllable loads, and non-controllable loads of the power generating farm (see, at least, paragraphs 0068-0069, etc. which disclose “In particular, the power supply 163 may be connected or connectable for energy supply to pumps or fans 167, may be connected to a pitching system 169, may be connected to a yawning system 171 and may be connected to measurement equipment 173 and may further be connected to a DC link pre-charging equipment 175 which may all or at least in part need electrical energy in order to support starting the wind turbine”).
Regarding Claim 3:
Brogan teaches the limitations of the preceding claim 2. Brogan further discloses wherein the one or more parameters comprise at least one of one or more environmental conditions, a layout of the inverter-based resources, the one or more local loads, one or more power reserve requirements, or combinations thereof (see, at least, paragraph 0020, “At amount of energy storage in X wind turbines…” reading on “one or more power reserve requirements” or paragraphs 0068-0069, etc. “…low wind period” reading on “one or more environmental conditions”).
Regarding Claim 4:
Brogan teaches the limitations of the preceding claim 2. Brogan further discloses wherein utilizing the grid forming capability of the subset of the plurality of inverter-based resources for initial start-up further comprises: soft starting the subset of the plurality of inverter-based resources using, at least, the anchor power generating asset and at least one of the one or more local loads or a grid following capability of the subset of the plurality of inverter-based resources (see, at least, paragraphs 0068-0069, claims 1, 14, etc. which disclose the start up is a combination of wind power and grid independent power supply comprising at least one of: a Diesel and/or hydrogen powered generator; a solar cell system; an electric energy storage, in particular battery, accumulator, capacitor bank).
Regarding Claim 5:
Brogan teaches the limitations of the preceding claim 4. Brogan further discloses wherein soft starting the subset of the plurality of inverter-based resources using, at least, the anchor power generating asset and at least one of the one or more local loads or the grid following capability of the subset of the plurality of inverter-based resources further comprises: setting a voltage reference of the subset of the plurality of inverter-based resources to a nominal voltage; setting a reference frequency of the subset of the plurality of inverter-based resources to a nominal frequency (see, at least paragraphs 0036-0038, 0082, claim 1, claim 2, etc. which disclose a reference voltage may be equal to a nominal voltage, and performing the respective grid forming function by the at least one first wind turbine to achieve the reference voltage, as well as a nominal frequency associated with the collector system voltage); and utilizing the grid following capability for the subset of the plurality of inverter-based resources to determine an active power reference and a reactive power reference (see, at least paragraphs 0036-0040, 0060, 0065, 0076-0086, claim 1, claim 2, claims 8-9, etc. which disclose the respective matching to active and reactive power demand of the collector system, i.e., determining an active and reactive power reference through utilization of the grid following capability).
Regarding Claim 14:
Brogan teaches the limitations of the preceding claim 1. Brogan further discloses wherein the anchor power generating asset is an anchor generator at the power generating farm (Fig. 1, energy supply 103am 103b, 103c each respectively by wind turbines 101a, 101b, 101c, etc., and their related discussion).
Regarding Claim 15:
Brogan et al. discloses a wind farm (Fig. 1, wind park 100 with wind turbines 101a, 101b, 101c, etc.) connected to an electrical grid (Fig. 1, grid 109), the wind farm comprising: a plurality of wind turbines (Fig. 1, wind turbines 101a, 101b, 101c, etc., and their related discussion; see, at least, claim 1, “starting at least one first wind turbine…”) connected to the electrical grid via a transmission network (Fig. 1, collector system 106 comprising cables 105 for connecting the plurality of wind turbines to grid 109 as shown, and their related discussion; see, at least, paragraph 0057); a controller comprising at least one processor (Fig. 1, controller 119 and its related discussion; see, at least, paragraphs 0020, 0025, 0060, 0067, etc. which disclose the controller including a control algorithm for carrying out the respective self-managing processes), the at least one processor configured to perform a plurality of operations, the plurality of operations comprising: selecting, at least, a subset of the plurality of wind turbines (Fig. 1, one of wind turbines 101a, 101b, 101c, etc., and their related discussion; see, at least, claim 1, “starting at least one first wind turbine…”) having grid forming capability (see, at least, claim 1, “… each being equipped with…a grid forming function…”) and an anchor power generating asset that are capable of contributing to the blackstart based on one more parameters (see, at least, claim 1, “…utilizing the respective grid independent energy supply for starting…” claim 14, “… wherein at least one of the grid independent energy supply… comprises at least one of: a Diesel and/or hydrogen powered generator; a solar cell system; an electric energy storage, in particular battery, accumulator, capacitor bank.” The anchor power generating asset read on by the respective grid independent energy supply comprising at least one of the assets as discussed); utilizing the grid forming capability of the subset of the plurality of inverter-based resources for initial start-up to bring the subset of the plurality of inverter-based resources online (see, at least, claim 1, “…starting at least one first wind turbine, each being equipped with an utility grid independent energy supply and a grid forming function, to produce electrical energy from wind energy, thereby utilizing the respective grid independent energy supply for starting; performing the grid forming function by the at least one first wind turbine to achieve a reference voltage in the collector system…”) and form a plurality of islands (see, at least, paragraphs 0080-0081, 0086-0088, claims 1, 3, etc. which disclose the start up method including connecting the first wind turbine, thereby forming a plurality of islands associated with the remaining wind turbines 101x), thereby partially re-energizing the transmission network and enabling restoration of one or more critical loads within a first time period during the blackstart (see, at least, claim 3, paragraphs 0069-0073, etc., which discloses “… allows them to supply the auxiliary loads (for example 167, 169, 171, 173, 175) for a given number of hours and pre-charge the main converter DC link 141…”); and during a subsequent, second time period, further energizing the transmission network to fully restore the electrical grid to normal operation (see, at least, claims 1, 3, etc. which disclose “starting at least one second wind turbine and/or at least one third wind turbine to produce energy by conversion of wind energy, thereby utilizing energy provided in the collector system for starting…”).
Regarding Claim 16:
Brogan teaches the limitations of the preceding claim 15. Brogan further discloses wherein the one or more parameters comprise at least one of one or more environmental conditions, a layout of the inverter-based resources, the one or more local loads, one or more power reserve requirements, or combinations thereof (see, at least, paragraph 0020, “At amount of energy storage in X wind turbines…” reading on “one or more power reserve requirements” or paragraphs 0068-0069, etc. “…low wind period” reading on “one or more environmental conditions”).
Regarding Claim 17:
Brogan teaches the limitations of the preceding claim 15. Brogan further discloses wherein utilizing the grid forming capability of the plurality of wind turbines for initial start-up further comprises: soft starting the subset of the plurality of wind turbines using, at least, the anchor power generating asset and at least one of the one or more local loads or a grid following capability of the subset of the plurality of inverter-based resources (see, at least, paragraphs 0068-0069, claims 1, 14, etc. which disclose the start up is a combination of wind power and grid independent power supply comprising at least one of: a Diesel and/or hydrogen powered generator; a solar cell system; an electric energy storage, in particular battery, accumulator, capacitor bank).
Regarding Claim 18:
Brogan teaches the limitations of the preceding claim 17. Brogan further discloses wherein soft starting the subset of the plurality of wind turbines using, at least, the anchor power generating asset and at least one of the one or more local loads or the grid following capability of the subset of the plurality of wind turbines further comprises: setting a voltage reference to a nominal voltage and a reference frequency to a nominal frequency for the subset of the plurality of inverter-based resources; setting the reference frequency to the nominal frequency for the subset of the plurality of inverter-based resources (see, at least paragraphs 0036-0038, 0082, claim 1, claim 2, etc. which disclose a reference voltage may be equal to a nominal voltage, and performing the respective grid forming function by the at least one first wind turbine to achieve the reference voltage, as well as a nominal frequency associated with the collector system voltage); and utilizing the grid following capability for the subset of the plurality of wind turbines to determine an active power reference and a reactive power reference (see, at least paragraphs 0036-0040, 0060, 0065, 0076-0086, claim 1, claim 2, claims 8-9, etc. which disclose the respective matching to active and reactive power demand of the collector system, i.e., determining an active and reactive power reference through utilization of the grid following capability).
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) 6-10 and 19-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Brogan et al. (U.S. Patent Publication Number 2020/0400120) in view of Rodriguez-Cabero et al. (IEEE, “Virtual Impedance Design Considerations for Virtual Synchronous Machines in Weak Grids”).
Regarding Claim 6:
Brogan teaches the limitations of the preceding claim 5. Brogan further discloses wherein utilizing the grid forming capability of the subset of the plurality of inverter-based resources for initial start-up further comprises: coordinating the subset of the plurality of inverter-based resources to maintain corresponding voltage and frequency of the subset of the plurality of inverter-based resources (see, at least, paragraph 0025 which discloses “A park level controller for high level coordination…”, paragraphs 0097-0101, etc. which provide further insight into the “park level coordination”). While Brogan discloses the utilization of a virtual synchronous machine (VSM) type power control, Brogan fails to teach such control “using a dynamic virtual impedance”.
However, Rodriguez-Cabero et al. discloses such VSM control as using a dynamic virtual impedance (see, at least, Abstract which discloses “This control technique is commonly referred to as Virtual Synchronous Machine (VSM) and recent studies have shown that VSMs are sensitive to variations in the network parameters if no countermeasures in form of virtual impedances are applied.”). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to realize the VSM type power control of Brogan as using a dynamic virtual impedance, as taught within Rodriguez-Cabero, as Rodriguez-Cabero explains that VSM control is sensitive to variations in network parameters and that applying virtual impedance serves as a countermeasure to improve system stability, robustness, and reliable operation under changing network conditions.
Regarding Claim 7:
Modified Brogan teaches the limitations of the preceding claim 6. Modified Brogan in further view of Brogan, discloses wherein utilizing the grid forming capability of the subset of the plurality of inverter-based resources for initial start-up further comprises: monitoring the voltage and the frequency of the subset of the plurality of inverter-based resources to maintain stability thereof (see, at least, paragraphs 0034-0035, 0063, claim 5, etc.).
Regarding Claim 8:
Modified Brogan teaches the limitations of the preceding claim 6. Modified Brogan, in further view of Brogan, discloses wherein the plurality of inverter-based resources is a plurality of wind turbines (Fig. 1, wind turbines 101a, 101b, 101c, etc., and their related discussion), wherein coordinating the subset of the plurality of inverter-based resources to maintain corresponding voltage and frequency of the subset of the plurality of inverter-based resources using a dynamic virtual impedance further comprises: using the dynamic virtual impedance in control of a power converter of each wind turbine in the subset of the plurality of wind turbines to provide stable start-up of the subset of the plurality of wind turbines (see, at least, paragraphs 0011-0015, 0020, 0028-0034, etc. which disclose the respective converter associated with each wind turbine, as well as Rodriguez-Cabero Section IV. Stability Analysis beginning at page 1482 through page 1485 which disclose the use of virtual impedance to mitigate the impact of the grid impedance, especially under weak grid conditions).
Regarding Claim 9:
Modified Brogan teaches the limitations of the preceding claim 6. Modified Brogan, in further view of Brogan, discloses determining the dynamic virtual impedance as a function of a combination of at least two of the following: one or more gains, one or more factors relating to a state of the plurality of inverter-based resources, a cable impedance, a distance between neighboring inverter-based resources, transformer impedance in energization path, and a nominal impedance, the start of the plurality of inverter-based resources comprises at least one of a start-up or steady-state (see, at least, paragraphs 0057, 0061, 0066, which disclose the respective considerations of operating states related to the wind turbines of the system, the components of the system, such as cables 105 (and potentially other components like capacitor banks, transformer, filters, and the like), as well as the teachings of Rodriguez-Cabero with respect to the dynamic virtual impedance as previously discussed. That is, the respective combination teaches the consideration of such factors so as to ensure and maintain grid stability through use of the VSM control technique, including the dynamic virtual impedance as laid out within Rodriguez-Cabero).
Regarding Claim 10:
Modified Brogan teaches the limitations of the preceding claim 9. Modified Brogan, in further view of Brogan, discloses wherein utilizing the grid forming capability of the subset of the plurality of inverter-based resources for initial start-up further comprises: synchronizing or spacing apart timing of start-up of the subset of the plurality of inverter-based resources to improve coordination (see, at least, paragraphs 0079-0080, 0087, etc.).
Regarding Claim 19:
Brogan teaches the limitations of the preceding claim 18. Brogan further discloses wherein utilizing the grid forming capability of the subset of the plurality of wind turbines for initial start-up further comprises: coordinating the subset of the plurality of wind turbines to maintain corresponding voltage and frequency of the subset of the plurality of wind turbines (see, at least, paragraph 0025 which discloses “A park level controller for high level coordination…”, paragraphs 0097-0101, etc. which provide further insight into the “park level coordination”). While Brogan discloses the utilization of a virtual synchronous machine (VSM) type power control, Brogan fails to teach such control “using a dynamic virtual impedance”.
However, Rodriguez-Cabero et al. discloses such VSM control as using a dynamic virtual impedance (see, at least, Abstract which discloses “This control technique is commonly referred to as Virtual Synchronous Machine (VSM) and recent studies have shown that VSMs are sensitive to variations in the network parameters if no countermeasures in form of virtual impedances are applied.”), and wherein coordinating the subset of the plurality of wind turbines to maintain corresponding voltage and frequency of the subset of the plurality of wind turbines using a dynamic virtual impedance further comprises using the dynamic virtual impedance in control of a power converter of each wind turbine in the subset of the plurality of wind turbines to provide stable start-up of the subset of the plurality of wind turbines (Section IV. Stability Analysis beginning at page 1482 through page 1485 which disclose the use of virtual impedance to mitigate the impact of the grid impedance, especially under weak grid conditions . See also Brogan: at least, paragraphs 0011-0015, 0020, 0028-0034, etc. which disclose the respective converter associated with each wind turbine). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to realize the VSM type power control of Brogan as using a dynamic virtual impedance, as taught within Rodriguez-Cabero, as Rodriguez-Cabero explains that VSM control is sensitive to variations in network parameters and that applying virtual impedance serves as a countermeasure to improve system stability, robustness, and reliable operation under changing network conditions.
Regarding Claim 20:
Modified Brogan teaches the limitations of the preceding claim 19. Modified Brogan, in further view of Brogan, discloses wherein utilizing the grid forming capability of the subset of the plurality of wind turbines for initial start-up further comprises: synchronizing or spacing apart timing of start-up of the subset of the plurality of wind turbines to improve coordination (see, at least, paragraphs 0079-0080, 0087, etc.).
Allowable Subject Matter
Claims 11-13 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:
Dependent claim 11 is currently believed to be directed towards a non-obvious improvement over the prior art of record. While the prior art discloses a similar method for a synchronized blackstart within a power generating farm system, the prior art of record fails to appropriately teach or suggest: “determining whether the stability is able to be maintained by the subset of the plurality of inverter-based resources” in addition to the subsequent control which is required to take place under the conditions of whether the stability determination indicates stability is unable to be maintained or is able to be maintained as recited within the current claim language. It appears as though claim 11, if rewritten in its entirety in independent form, would be in condition for allowance, as said claim limitations appear to be directed towards a non-obvious improvement over the prior art of record. Dependent claims 12 and 13 are objected to as being ultimately dependent upon claim 11.
Conclusion
Prior art deemed relevant, but not currently relied upon:
Price U.S. Patent Publication Number 2020/0153250
Abeyasekera U.S. Patent Publication Number 2021/0047997
Abeyasekera U.S. Patent Publication Number 2022/0364546
Biris et al. U.S. Patent Publication Number 2023/0048911
Massoud et al. U.S. Patent Number 11,777,310
Hart et al. U.S. Patent Publication Number 2023/0369865
Basak et al. U.S. Patent Publication Number 2024/0072698
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/JOSEPH N INGE/Examiner, Art Unit 2836
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