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) 1-4 is rejected under 35 U.S.C. 102(a)(1) as being anticipated by Li et al. (CN 114784847 A).
Regarding independent claim 1, Li teaches a high voltage ride-through method for wind power based on coordinated control of energy storage and reactive compensation devices (Fig. 2), comprising following steps:
step 100: fault determination based on voltages of grid connection points of wind farms (pg. 4 of provided translation, paragraph starting “The first aspect of…”; pg. 5 of translation, paragraph starting “The first level is to…”);
step 200: setting voltage fluctuation thresholds of grid connection points under faults, and determining whether to implement super capacitor, doubly-fed induction generator, and static var generator coordinated control strategies based on voltage fluctuation thresholds of grid connection points of commutation bus voltages under faults (pg. 5 of translation, paragraph starting “The first level is to…”);
step 300: calculating reactive power shortage of grid connection points under faults based on the control strategies (pg. 5 of translation, paragraph starting “The first level is to…”);
step 400: determining whether the reactive power shortage of grid connection points is within wind farm regulation ranges and implement corresponding control strategies to adjust voltages based on the reactive power shortage (pg. 5 of translation, paragraph starting “The first level is to…”); and
step 500: determining whether to utilize static var generators to compensate reactive power based on reactive power compensation of doubly-fed induction generators according to deviations between adjusted voltages and steady-state values (pg. 5 of translation, paragraph starting “The first level is to…”).
Regarding claim 2, Li teaches step 200 of setting voltage fluctuation thresholds of grid connection points under faults, and determining whether to implement super capacitor, doubly-fed induction generator, and static var generator coordinated control strategies based on voltage fluctuation thresholds of grid connection points of commutation bus voltages under faults, specifically comprises:
setting voltage fluctuation thresholds of grid connection points under faults, and determining whether grid connection point voltages under faults are greater than the voltage fluctuation thresholds (i.e. if the voltage of the grid-connected point drops enough to need reactive power compensation by the DFIG and/or SVG), if so, implementing coordinated control strategies, and if not, not implementing coordinated control strategies (pg. 5 of provided translation, paragraph starting “The first level is to…”).
Regarding claim 3, Li teaches step 400 of determining whether the reactive power shortage of grid connection points is within wind farm regulation ranges and implement corresponding control strategies to adjust voltages based on the reactive power shortage, specifically comprising:
determining whether the reactive power shortage of grid connection points under faults is less than a sum of reactive power limits of doubly-fed induction generators under constant active power outputs and reactive power limits of super capacitor-side converters (i.e. when the reactive power shortage can be satisfied by the DFIG alone), if so, implementing improved control strategies for energy storage systems to adjust voltages; if not, then utilizing static var generators to compensate for differences and adjust voltages, and re-determining whether there is a need to implement the coordinated control strategies (“to maintain the stable operation”) (pg. 5 of provided translation, paragraph starting “The first level is to…”).
Regarding claim 4, Li teaches the improved control strategies comprise: dividing grid-tie inverters into following two operating modes (bottom half of page 5):
a first mode: during steady-state operation, high voltage ride-through modules take no action, active power output by super capacitors is equal to active power of converters when losses of converters are negligible, reference values of q-axis components of currents flowing from converters to grids are zero, and no reactive power exchange is performed with grids (i.e. when the voltage at the grid connected point doesn’t drop); and
a second mode: when a fault occurs, a high voltage ride-through operation mode is entered and works in an inductive reactive power compensation state, so that reactive power regulation capability of wind farms is utilized and active power stabilization function of super capacitors are leveraged, wherein active power setting values of super capacitors and converters are minimum values of maximum active power absorbed by systems, and reactive power reference values output from converters depend on reactive power regulation limits of wind farms (i.e. when the voltage at the grid connected point does drop).
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) 5 is rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (CN 114784847 A). Li teaches the high voltage ride-through method as described above. Li also teaches step 500 of determining whether to utilize static var generators to compensate reactive power based on reactive power compensation of doubly-fed induction generators according to deviations between adjusted voltages and steady-state values, specifically comprises:
calculating absolute values of differences between real-time measured voltages of grid connection points and steady-state voltages of grid connection points (determining how much/far the voltage has dropped; pg. 5 of provided translation, paragraph starting “The first level is to…”), and
determining whether the absolute values of differences are greater than a certain level (i.e. the level up to where the DFIG can provide enough reactive compensation power alone), if not, using doubly-fed induction generators to compensate for differences in reactive power, if yes, first using the static var generators to compensate until the absolute values of differences between real-time measured voltages of grid connection points and steady-state voltages of grid connection points are less than a certain level, and then using doubly-fed induction generators to compensate for differences in reactive power (pg. 5 of provided translation, paragraph starting “The first level is to…”).
Li fails to explicitly teach determining whether the absolute values of differences are specifically greater than 0.2. However, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have the difference threshold be 0.2, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233. It is also a matter of design choice based on the reactive power compensation capabilities of the DFIG.
Conclusion
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DMP
1/7/2026
/DANIEL CAVALLARI/Primary Examiner, Art Unit 2836