Notice of Pre-AIA or AIA Status
1. The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Detailed Action
2. This office action is in response to the filing with the office dated 01/29/2025.
Information Disclosure Statement
3. The information disclosure statements (IDS) submitted on 01/29/2025 is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
Claim Rejections – 35 U.S.C. 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.
4. Claims 1, 2, 8, 14-16 are rejected under 35 U.S.C. 102 (a) (1) as being anticipated by Gupta et al (US 2013/0264824 A1).
Regarding independent claim 1, Gupta et al (US 2013/0264824 A1) teaches, A method for identifying a defect in at least one electrical component of an energy installation connected to an electrical grid (a method for operating a power generation system coupled to a power grid during a grid fault event or a grid unbalance event paragraph [0001]), the energy installation including: at least one generator unit having at least one multiple-phase generator configured for producing electrical energy and a multiple-phase local transformer with a low-voltage side and a high-voltage side fed by the generator on the low-voltage side (The wind turbine 300 has
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a generator 302, a full scale power converter (inclusive of grid filter) 304 and a transformer (e.g. nacelle transformer) 306, multi-phase connection is shown in figure 3, paragraph [0090]); wherein the method comprises the steps of: monitoring a local voltage asymmetry value on the low-voltage side of the local transformer (during asymmetrical fault condition, the voltage seen at the LV side 308 of the transformer 306 has a non-zero positive sequence component and a non-zero negative sequence component. An example of a positive sequence component 402 and a negative sequence component 404 of the voltage at the LV side 308 of the transformer 306 are shown in FIG. 4. [0090]); and, comparing, in a first comparing step, the monitored local voltage asymmetry value to a predetermined threshold voltage asymmetry value ([0098] FIG. 8 shows a flowchart 800 of a method for operating a power generation system coupled to a power grid during a grid unbalance event or a grid fault event. At 802, a power grid voltage is determined. At 804, a negative sequence grid voltage of the power grid is determined from the power grid voltage. At 806, the determined negative sequence grid voltage is compared with a reference voltage. In one embodiment, the reference voltage may be determined after 802 or 804 of the flowchart 800. At 808, a negative sequence reactive injection current for a possible injection by the power generation system into the power grid is determined based on the result of the comparison. Also see paragraph [0099]).
Regarding dependent claim 2, Gupta et al (US 2013/0264824 A1) teaches the method of claim 1.
Gupta et al (US 2013/0264824 A1) further teaches, wherein the at least one electrical component comprises at least one of the following: i) the local transformer (transformer in figure 3); and, ii) a part of an intermediate electrical network including a collector bus and wherethrough the at least one generator unit is connected to the electrical grid (figure 1, 3, paragraphs [0001], [0034]).
Regarding dependent claim 8, Gupta et al (US 2013/0264824 A1) teaches the method of claim 1.
Gupta et al (US 2013/0264824 A1) further teaches, wherein, from the moment on when the at least one generator unit is being connected to the energy installation, an output power of the at least one generator unit is monitored and compared to a predetermined output power threshold in a third comparing step (Paragraphs [0151], [0152]).
Regarding independent claim 14, Gupta et al (US 2013/0264824 A1) teaches, A generator unit configured for being operated in an energy installation (a method for operating a power generation system coupled to a power grid during a grid fault event or a grid unbalance event paragraph [0001], Wind farm (paragraphs [0100], [0105], [0146])) and being configured to identify a defect in at least one electrical component of the energy installation connected to an electrical grid (The wind turbine 300 has a generator 302, a full scale power converter (inclusive of grid filter) 304 and a transformer (e.g. nacelle transformer) 306, multi-phase connection is shown in figure 3, paragraph [0090]), the energy installation including at least one generator unit having at least one multiple-phase generator configured for producing electrical
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energy and a multiple-phase local transformer with a low-voltage side (The wind turbine 300 has a generator 302, a full scale power converter (inclusive of grid filter) 304 and a transformer (e.g. nacelle transformer) 306, multi-phase connection is shown in figure 3, paragraph [0090]) and a high-voltage side fed by the generator on the low-voltage side (The wind turbine 300 has a generator 302, a full scale power converter (inclusive of grid filter) 304 and a transformer (e.g. nacelle transformer) 306, multi-phase connection is shown in figure 3, paragraph [0090]), the generator unit comprising: a monitoring device configured for monitoring the local voltage asymmetry value on the low-voltage side of the local transformer of the at least one generator unit (during asymmetrical fault condition, the voltage seen at the LV side 308 of the transformer 306 has a non-zero positive sequence component and a non-zero negative sequence component. An example of a positive sequence component 402 and a negative sequence component 404 of the voltage at the LV side 308 of the transformer 306 are shown in FIG. 4. [0090]); and, a computational device configured for comparing the measured local voltage asymmetry value to a predetermined voltage asymmetry threshold ([0098] FIG. 8 shows a flowchart 800 of a method for operating a power generation system coupled to a power grid during a grid unbalance event or a grid fault event. At 802, a power grid voltage is determined. At 804, a negative sequence grid voltage of the power grid is determined from the power grid voltage. At 806, the determined negative sequence grid voltage is compared with a reference voltage. In one embodiment, the reference voltage may be determined after 802 or 804 of the flowchart 800. At 808, a negative sequence reactive injection current for a possible injection by the power generation system into the power grid is determined based on the result of the comparison. Also see paragraph [0099]).
Regarding dependent claim 15, Gupta et al (US 2013/0264824 A1) teaches the generator unit of claim 14.
Gupta et al further teaches, wherein said energy installation includes the at least one generator unit (FIG. 3 shows a schematic diagram of a full scale converter based wind turbine 300. The wind turbine 300 has a generator 302, a full scale power converter (inclusive of grid filter) 304 and a transformer (e.g. nacelle transformer) 306, paragraph [0090]).
Regarding dependent claim 16, Gupta et al (US 2013/0264824 A1) teaches the generator unit of claim 14.
Gupta et al further teaches, An energy installation, comprising the generator unit of claim 14 (wind farm (paragraphs [0100], [0105], [0146]).
Claim Rejections – 35 U.S.C. 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 (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 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.
5. Claims 3-7, 9-11 are rejected under 35 U.S.C. 103 as being unpatentable over Gupta et al (US 20130264824 A1) and in view of Gajic et al (US 2014/0117912 A1)
Regarding dependent claim 3, Gupta et al (US 20130264824 A1) teaches the method of claim 1.
Gupta et al (US 20130264824 A1) further teaches, wherein the energy installation further includes a grid-side multiple-phase main transformer connected, on a low-voltage side thereof (FIG. 3 shows a schematic diagram of a full scale converter based wind turbine 300. The wind turbine 300 has a generator 302, a full scale power converter (inclusive of grid filter) 304 and a transformer (e.g. nacelle transformer) 306. A voltage at a low voltage (LV) side 308 of the transformer 306 is used for wind turbine/converter control strategy, figure 3, [0090]), wherein the method comprises the following further steps: monitoring a grid-side voltage asymmetry value on the low-voltage side or on the high- voltage side of the main
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transformer; and, comparing, in a second comparing step, the local voltage asymmetry value of the at least one generator unit to the grid-side voltage asymmetry value ([0098] FIG. 8 shows a flowchart 800 of a method for operating a power generation system coupled to a power grid during a grid unbalance event or a grid fault event. At 802, a power grid voltage is determined. At 804, a negative sequence grid voltage of the power grid is determined from the power grid voltage. At 806, the determined negative sequence grid voltage is compared with a reference voltage. In one embodiment, the reference voltage may be determined after 802 or 804 of the flowchart 800. At 808, a negative sequence reactive injection current for a possible injection by the power generation system into the power grid is determined based on the result of the comparison. Also see paragraphs [0099], [0100])
Gupta et al does not explicitly teach a high-voltage side of the local transformer of the at least one generator unit, and connected, on a high- voltage side, to the electrical grid.
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Gajic et al (US 2014/0117912 A1) teaches, a high-voltage side of the local transformer of the at least one generator unit, and connected, on a high- voltage side, to the electrical grid ([0044] FIG. 1a illustrates an arrangement for protecting a synchronous generator 1. The synchronous generator 1 is connected to a power grid 3, such as a main national power grid 3, and arranged to generate and transfer electric power into the power grid 3. The synchronous generator 1 has a neutral side 2 wherein the windings of the synchronous generator 1 are interconnected in a Y-coupling and grounded via an impedance or a grounding transformer. The synchronous generator also comprises a terminal side 4 where each winding of the generator is connected to a respective conductor 5, one for each phase. The synchronous generator is connected to the power grid 3 by means of the conductors 5, such as bus bars or cables, and circuit breakers 7, arranged for connecting and disconnecting the synchronous generator 1 from the power grid 3. The synchronous generator is a three-phase synchronous generator 1 connected to a three-phase grid 3, and one conductor 5 and one circuit breaker 7 is arranged for each phase a, b, c. The connection between the synchronous generator 1 and the power grid 3 also includes a step-up transformer arrangement 9, so that the low voltage level power in generator side could be transformed into high voltage level power to the power grid 3 for possible long distance power transmission. The synchronous power generator 1 is mechanically coupled to a turbine system 6, for example a hydro power turbine, or steam turbine from a nuclear reactor or fossil fuel boiler).
Therefore it would have been obvious to one of the ordinary skill in the art before the effective filing date of the claimed invention, to have modified the teachings of Gupta et al (US 20130264824 A1) by providing a high voltage side transformer connected to the grid as taught by Gajic et al (figure 1a, paragraph [0044], [0032]).
One of the ordinary skill in the art would have been motivated to make such a modification so that so that the low voltage level power in generator side could be transformed into high voltage level power to the power grid 3 for possible long distance power transmission, as taught by Gajic et al (figure 1a, paragraph [0044])
Regarding dependent claim 4, Gupta et al (US 20130264824 A1) and Gajic et al (US 2014/0117912 A1) teach the method of claim 3.
Gupta et al (US 20130264824 A1) further teaches, wherein the grid-side voltage asymmetry value is a weighted grid-side voltage asymmetry value that is obtained by multiplying the monitored grid-side voltage asymmetry value by a predetermined factor ([0093] The voltage U on the x-axis of FIG. 7 can be (a) positive sequence voltage, (b) minimum line voltage, (c) maximum line voltage, (d) minimum phase voltage or (e) maximum phase voltage. For a symmetrical grid fault, any one of the above five voltages can be used as the voltage U on the x-axis. For an asymmetrical grid fault, one of positive sequence voltage, minimum line voltage and minimum phase voltage may be used for the x-axis. The voltage used for the x-axis is dependent on the country/region/grid code. Some grid codes may use any one of positive sequence voltage, minimum line voltage and maximum line voltage for symmetrical grid fault, and may use any one of positive sequence voltage and minimum line voltage for asymmetrical grid fault. Therefore, by providing all the above options for the voltage U on the x-axis, the wind turbine can be configured for any country/region/grid code. Also see paragraphs [0098]-[0100]).
Regarding dependent claim 5, Gupta et al (US 20130264824 A1) and Gajic et al (US 2014/0117912 A1) the method of claim 3.
Gupta et al (US 20130264824 A1) further teaches, wherein the first comparing step and the second comparing step are performed by the at least one generator unit (figure 3, paragraph [0090]).
Regarding dependent claim 6, Gupta et al (US 20130264824 A1) and Gajic et al (US 2014/0117912 A1) teach the method of claim 3.
Gupta et al (US 20130264824 A1) further teaches, wherein, when the local voltage asymmetry value exceeds the predetermined threshold voltage asymmetry value and when the local voltage asymmetry value exceeds the grid-side voltage asymmetry value (paragraphs [0093], [0098]-[0100]).
Gupta et al does not teach an alarm step is triggered for the at least one generator unit.
Gajic et al (US 2014/0117912 A1) teaches, wherein, when the local voltage asymmetry value exceeds the predetermined threshold voltage asymmetry value and when the local voltage asymmetry value exceeds the grid-side voltage asymmetry value, an alarm step is triggered for the at least one generator unit ([0045] The arrangement also comprises a monitoring and protection system 10-17 comprising current measuring devices 10 in the form of current transformers 10 and voltage measuring devices 11 in the form of voltage transformers 11, one for each phase 10a-c and 11a-c, respectively. Each measuring device 10-11 is connected by means of secondary cables to a protection unit 12 and arranged and adapted for transferring measurements of currents and voltages to the protection unit, the measuring devices are provided to transfer each phase current (I.sub.a, I.sub.b, I.sub.c) and each phase voltage (V.sub.a, V.sub.b, V.sub.c) to the protection unit 12. Further, the protection unit 12 is operatively connected by secondary cables 13 to the circuit breakers 7a-c and arranged to selectively transfer trip commands to each circuit breaker 7a-c and adapted to selectively connect or disconnect the synchronous generator 1 to and from the power grid 3. The protection unit 12 operatively connected by secondary cables (such as 17 and 36) to the other parts of the generating system, including turbine 6 and rotor exciter system 30 to selectively connect or disconnect the turbine 6 and the rotor exciter system 30. The protection unit 12 includes computer hardware, screen display 14, alarm system 15 and communication system which connect the protection unit 12 with a substation automation system 16 where the operators 19 get alarm signals upon detecting a failure. The detecting and protecting system is adapted to measure the phase currents and the phase voltages at the terminal side 4 of the synchronous generator 1. The detecting and protecting system is adapted to analyse the measurements and take action if a fault is detected, such as alerting an operator visually on the screen, audibly via the loudspeaker, trip the generator 1 from the power grid 3, disconnect the turbine and disconnect the rotor excitation system of the synchronous generator. [0058] The protection unit 12 is also provided with means 51-53 for protecting the synchronous generator 1 and the power system 3 upon detecting a fault. For this purpose the protection unit 12 comprises a circuit breaker tripping unit 51, which is operatively connected to the circuit breakers 7 that connect the synchronous generator 1 to the power grid 3. The protection unit also comprises a visual indicator 52 operatively connected to a display 14 and adapted to output a visual indication for an operator indicating a fault, preferably indicating type of fault, such as a winding fault, for example, and preferably indicating an inter-turn fault and in which phase winding of the synchronous generator the inter-turn fault is located. The protection unit 12 is adapted to provide such a visual indication upon detecting the corresponding fault to the operator 19 through substation automation system 16. The protection unit 12 further comprises an audible alarm output 53 connected to a loudspeaker 15 for the operator 19 of the substation automation system 16 for alarming when a fault is determined. The protection unit may suitably be part of substation automation system 16 which is provided for controlling the overall power generating apparatus including a turbine, a generator 1, a transformer 9 substation and connections to a power grid 3.[0074] The method steps of monitoring the synchronous generator, step 501-511, is followed by a protecting step 513, so that the monitoring also includes taking action when an internal fault is discovered. The protecting step 513 includes at least one of making a visual indication for an operator, making an audible alarm, stopping the power generating process by tripping the generator circuit breaker and disconnecting the generator from the power grid. Preferably, the protecting step 513 is followed by a fault report creating step 514. Also, the created fault report from step 514 is suitably transferred to operator work stations and control arrangements of the power generating process.
Therefore it would have been obvious to one of the ordinary skill in the art before the effective filing date of the claimed invention, to have modified the teachings of Gupta et al (US 20130264824 A1) by providing a monitoring and protection system which includes an alarm as taught by Gajic et al (US 2014/0117912 A1) (paragraphs [0045], [0058], [0074]).
One of the ordinary skill in the art would have been motivated to make such a modification so that an audible alarm output 53 connected to a loudspeaker 15 for the operator 19 of the substation automation system 16 for alarming when a fault is determined. The protection unit may suitably be part of substation automation system 16 which is provided for controlling the overall power generating apparatus including a turbine, a generator 1, a transformer 9 substation and connections to a power grid 3, as taught by Gajic et al (US 2014/0117912 A1) (paragraphs [0045], [0058], [0074]).
Regarding dependent claim 7, Gupta et al (US 20130264824 A1), and Gajic et al (US 20140117912 A1) teach the method of claim 6.
Gupta et al (US 20130264824 A1) further teaches, wherein the alarm step is executed only when at least one of the following occurs: i) the local voltage asymmetry value exceeds the predetermined threshold voltage asymmetry value for a predetermined delay time; and, ii) the local voltage asymmetry value of the at least one generator unit exceeds the grid- side voltage asymmetry value for the predetermined delay time (paragraphs [0093], [0098]-[0100]).
Gupta et al does not teach an alarm step is executed.
Gajic et al (US 2014/0117912 A1) teaches, ([0045] The arrangement also comprises a monitoring and protection system 10-17 comprising current measuring devices 10 in the form of current transformers 10 and voltage measuring devices 11 in the form of voltage transformers 11, one for each phase 10a-c and 11a-c, respectively. Each measuring device 10-11 is connected by means of secondary cables to a protection unit 12 and arranged and adapted for transferring measurements of currents and voltages to the protection unit, the measuring devices are provided to transfer each phase current (I.sub.a, I.sub.b, I.sub.c) and each phase voltage (V.sub.a, V.sub.b, V.sub.c) to the protection unit 12. Further, the protection unit 12 is operatively connected by secondary cables 13 to the circuit breakers 7a-c and arranged to selectively transfer trip commands to each circuit breaker 7a-c and adapted to selectively connect or disconnect the synchronous generator 1 to and from the power grid 3. The protection unit 12 operatively connected by secondary cables (such as 17 and 36) to the other parts of the generating system, including turbine 6 and rotor exciter system 30 to selectively connect or disconnect the turbine 6 and the rotor exciter system 30. The protection unit 12 includes computer hardware, screen display 14, alarm system 15 and communication system which connect the protection unit 12 with a substation automation system 16 where the operators 19 get alarm signals upon detecting a failure. The detecting and protecting system is adapted to measure the phase currents and the phase voltages at the terminal side 4 of the synchronous generator 1. The detecting and protecting system is adapted to analyse the measurements and take action if a fault is detected, such as alerting an operator visually on the screen, audibly via the loudspeaker, trip the generator 1 from the power grid 3, disconnect the turbine and disconnect the rotor excitation system of the synchronous generator. [0058] The protection unit 12 is also provided with means 51-53 for protecting the synchronous generator 1 and the power system 3 upon detecting a fault. For this purpose the protection unit 12 comprises a circuit breaker tripping unit 51, which is operatively connected to the circuit breakers 7 that connect the synchronous generator 1 to the power grid 3. The protection unit also comprises a visual indicator 52 operatively connected to a display 14 and adapted to output a visual indication for an operator indicating a fault, preferably indicating type of fault, such as a winding fault, for example, and preferably indicating an inter-turn fault and in which phase winding of the synchronous generator the inter-turn fault is located. The protection unit 12 is adapted to provide such a visual indication upon detecting the corresponding fault to the operator 19 through substation automation system 16. The protection unit 12 further comprises an audible alarm output 53 connected to a loudspeaker 15 for the operator 19 of the substation automation system 16 for alarming when a fault is determined. The protection unit may suitably be part of substation automation system 16 which is provided for controlling the overall power generating apparatus including a turbine, a generator 1, a transformer 9 substation and connections to a power grid 3. [0074] The method steps of monitoring the synchronous generator, step 501-511, is followed by a protecting step 513, so that the monitoring also includes taking action when an internal fault is discovered. The protecting step 513 includes at least one of making a visual indication for an operator, making an audible alarm, stopping the power generating process by tripping the generator circuit breaker and disconnecting the generator from the power grid. Preferably, the protecting step 513 is followed by a fault report creating step 514. Also, the created fault report from step 514 is suitably transferred to operator work stations and control arrangements of the power generating process.
Therefore it would have been obvious to one of the ordinary skill in the art before the effective filing date of the claimed invention, to have modified the teachings of Gupta et al (US 20130264824 A1) by providing a monitoring and protection system which includes an alarm as taught by Gajic et al (US 2014/0117912 A1) (paragraphs [0045], [0058], [0074]).
One of the ordinary skill in the art would have been motivated to make such a modification so that an audible alarm output 53 connected to a loudspeaker 15 for the operator 19 of the substation automation system 16 for alarming when a fault is determined. The protection unit may suitably be part of substation automation system 16 which is provided for controlling the overall power generating apparatus including a turbine, a generator 1, a transformer 9 substation and connections to a power grid 3, as taught by Gajic et al (US 2014/0117912 A1) (paragraphs [0045], [0058], [0074]).
Regarding dependent claim 9, Gupta et al (US 20130264824 A1) and Gajic et al (US 20140117912 A1) teach the method of claim 8.
Gupta et al (US 20130264824 A1) further teaches, wherein, when the local voltage asymmetry value exceeds the predetermined threshold voltage asymmetry value and the measured output power exceeds the predetermined output power threshold for a predetermined observation time (paragraphs [0093], [0098]-[0100]).
Gupta et al does not teach, an alarm step is triggered.
Gajic et al (US 2014/0117912 A1) teaches, wherein, when the local voltage asymmetry value exceeds the predetermined threshold voltage asymmetry value and when the local voltage asymmetry value exceeds the grid-side voltage asymmetry value, an alarm step is triggered for the at least one generator unit ([0045] The arrangement also comprises a monitoring and protection system 10-17 comprising current measuring devices 10 in the form of current transformers 10 and voltage measuring devices 11 in the form of voltage transformers 11, one for each phase 10a-c and 11a-c, respectively. Each measuring device 10-11 is connected by means of secondary cables to a protection unit 12 and arranged and adapted for transferring measurements of currents and voltages to the protection unit, the measuring devices are provided to transfer each phase current (I.sub.a, I.sub.b, I.sub.c) and each phase voltage (V.sub.a, V.sub.b, V.sub.c) to the protection unit 12. Further, the protection unit 12 is operatively connected by secondary cables 13 to the circuit breakers 7a-c and arranged to selectively transfer trip commands to each circuit breaker 7a-c and adapted to selectively connect or disconnect the synchronous generator 1 to and from the power grid 3. The protection unit 12 operatively connected by secondary cables (such as 17 and 36) to the other parts of the generating system, including turbine 6 and rotor exciter system 30 to selectively connect or disconnect the turbine 6 and the rotor exciter system 30. The protection unit 12 includes computer hardware, screen display 14, alarm system 15 and communication system which connect the protection unit 12 with a substation automation system 16 where the operators 19 get alarm signals upon detecting a failure. The detecting and protecting system is adapted to measure the phase currents and the phase voltages at the terminal side 4 of the synchronous generator 1. The detecting and protecting system is adapted to analyse the measurements and take action if a fault is detected, such as alerting an operator visually on the screen, audibly via the loudspeaker, trip the generator 1 from the power grid 3, disconnect the turbine and disconnect the rotor excitation system of the synchronous generator. [0058] The protection unit 12 is also provided with means 51-53 for protecting the synchronous generator 1 and the power system 3 upon detecting a fault. For this purpose the protection unit 12 comprises a circuit breaker tripping unit 51, which is operatively connected to the circuit breakers 7 that connect the synchronous generator 1 to the power grid 3. The protection unit also comprises a visual indicator 52 operatively connected to a display 14 and adapted to output a visual indication for an operator indicating a fault, preferably indicating type of fault, such as a winding fault, for example, and preferably indicating an inter-turn fault and in which phase winding of the synchronous generator the inter-turn fault is located. The protection unit 12 is adapted to provide such a visual indication upon detecting the corresponding fault to the operator 19 through substation automation system 16. The protection unit 12 further comprises an audible alarm output 53 connected to a loudspeaker 15 for the operator 19 of the substation automation system 16 for alarming when a fault is determined. The protection unit may suitably be part of substation automation system 16 which is provided for controlling the overall power generating apparatus including a turbine, a generator 1, a transformer 9 substation and connections to a power grid 3.[0074] The method steps of monitoring the synchronous generator, step 501-511, is followed by a protecting step 513, so that the monitoring also includes taking action when an internal fault is discovered. The protecting step 513 includes at least one of making a visual indication for an operator, making an audible alarm, stopping the power generating process by tripping the generator circuit breaker and disconnecting the generator from the power grid. Preferably, the protecting step 513 is followed by a fault report creating step 514. Also, the created fault report from step 514 is suitably transferred to operator work stations and control arrangements of the power generating process.
Therefore it would have been obvious to one of the ordinary skill in the art before the effective filing date of the claimed invention, to have modified the teachings of Gupta et al (US 20130264824 A1) by providing a monitoring and protection system which includes an alarm as taught by Gajic et al (US 2014/0117912 A1) (paragraphs [0045], [0058], [0074]).
One of the ordinary skill in the art would have been motivated to make such a modification so that an audible alarm output 53 connected to a loudspeaker 15 for the operator 19 of the substation automation system 16 for alarming when a fault is determined. The protection unit may suitably be part of substation automation system 16 which is provided for controlling the overall power generating apparatus including a turbine, a generator 1, a transformer 9 substation and connections to a power grid 3, as taught by Gajic et al (US 2014/0117912 A1) (paragraphs [0045], [0058], [0074]).
Regarding dependent claim 10, Gupta et al (US 20130264824 A1) and Gajic et al (US 2014/0117912 A1) teach the method of claim 3.
Gupta et al (US 20130264824 A1) further teaches, wherein the at least one generator unit further includes a turbine driving the generator and, at least one of the following occurs: i) the turbine is stopped; and, ii) the at least one generator unit is electrically disconnected from the energy installation (paragraphs [0093], [0098]-[0100]).
Gupta et al does not teach, an alarm step is triggered.
Gajic et al (US 2014/0117912 A1) teaches, wherein, when the local voltage asymmetry value exceeds the predetermined threshold voltage asymmetry value and when the local voltage asymmetry value exceeds the grid-side voltage asymmetry value, an alarm step is triggered for the at least one generator unit ([0045] The arrangement also comprises a monitoring and protection system 10-17 comprising current measuring devices 10 in the form of current transformers 10 and voltage measuring devices 11 in the form of voltage transformers 11, one for each phase 10a-c and 11a-c, respectively. Each measuring device 10-11 is connected by means of secondary cables to a protection unit 12 and arranged and adapted for transferring measurements of currents and voltages to the protection unit, the measuring devices are provided to transfer each phase current (I.sub.a, I.sub.b, I.sub.c) and each phase voltage (V.sub.a, V.sub.b, V.sub.c) to the protection unit 12. Further, the protection unit 12 is operatively connected by secondary cables 13 to the circuit breakers 7a-c and arranged to selectively transfer trip commands to each circuit breaker 7a-c and adapted to selectively connect or disconnect the synchronous generator 1 to and from the power grid 3. The protection unit 12 operatively connected by secondary cables (such as 17 and 36) to the other parts of the generating system, including turbine 6 and rotor exciter system 30 to selectively connect or disconnect the turbine 6 and the rotor exciter system 30. The protection unit 12 includes computer hardware, screen display 14, alarm system 15 and communication system which connect the protection unit 12 with a substation automation system 16 where the operators 19 get alarm signals upon detecting a failure. The detecting and protecting system is adapted to measure the phase currents and the phase voltages at the terminal side 4 of the synchronous generator 1. The detecting and protecting system is adapted to analyse the measurements and take action if a fault is detected, such as alerting an operator visually on the screen, audibly via the loudspeaker, trip the generator 1 from the power grid 3, disconnect the turbine and disconnect the rotor excitation system of the synchronous generator. [0058] The protection unit 12 is also provided with means 51-53 for protecting the synchronous generator 1 and the power system 3 upon detecting a fault. For this purpose the protection unit 12 comprises a circuit breaker tripping unit 51, which is operatively connected to the circuit breakers 7 that connect the synchronous generator 1 to the power grid 3. The protection unit also comprises a visual indicator 52 operatively connected to a display 14 and adapted to output a visual indication for an operator indicating a fault, preferably indicating type of fault, such as a winding fault, for example, and preferably indicating an inter-turn fault and in which phase winding of the synchronous generator the inter-turn fault is located. The protection unit 12 is adapted to provide such a visual indication upon detecting the corresponding fault to the operator 19 through substation automation system 16. The protection unit 12 further comprises an audible alarm output 53 connected to a loudspeaker 15 for the operator 19 of the substation automation system 16 for alarming when a fault is determined. The protection unit may suitably be part of substation automation system 16 which is provided for controlling the overall power generating apparatus including a turbine, a generator 1, a transformer 9 substation and connections to a power grid 3.[0074] The method steps of monitoring the synchronous generator, step 501-511, is followed by a protecting step 513, so that the monitoring also includes taking action when an internal fault is discovered. The protecting step 513 includes at least one of making a visual indication for an operator, making an audible alarm, stopping the power generating process by tripping the generator circuit breaker and disconnecting the generator from the power grid. Preferably, the protecting step 513 is followed by a fault report creating step 514. Also, the created fault report from step 514 is suitably transferred to operator work stations and control arrangements of the power generating process.
Therefore it would have been obvious to one of the ordinary skill in the art before the effective filing date of the claimed invention, to have modified the teachings of Gupta et al (US 20130264824 A1) by providing a monitoring and protection system which includes an alarm as taught by Gajic et al (US 2014/0117912 A1) (paragraphs [0045], [0058], [0074]).
One of the ordinary skill in the art would have been motivated to make such a modification so that an audible alarm output 53 connected to a loudspeaker 15 for the operator 19 of the substation automation system 16 for alarming when a fault is determined. The protection unit may suitably be part of substation automation system 16 which is provided for controlling the overall power generating apparatus including a turbine, a generator 1, a transformer 9 substation and connections to a power grid 3, as taught by Gajic et al (US 2014/0117912 A1) (paragraphs [0045], [0058], [0074]).
Regarding dependent claim 11, Gupta et al (US 20130264824 A1) and Gajic et al (US 2014/0117912 A1) teach the method of claim 3.
Gupta et al (US 20130264824 A1) further teaches, wherein the energy installation is a wind farm (paragraphs [0100], [0105], [0146]).
6. Claims 12 and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Gupta et al (US 2013/0264824 A1) and in view of Grubic et al (US 2017/0176536 A1).
Regarding independent claim 12, Gupta et al (US 2013/0264824 A1) teaches, A storage device comprising: a non-transitory computer readable medium having program code (algorithm in paragraphs [0081], [0184], storage device and non-transitory medium are implicitly taught) for identifying a defect in at least one electrical component of an energy installation connected to an electrical grid (a method for operating a power generation system coupled to a power grid during a grid fault event or a grid unbalance event paragraph [0001]); wherein the energy installation includes at least one generator unit having at least one multiple-phase generator configured for producing electrical energy and a multiple-phase local transformer with a low-voltage side and a high-voltage side fed by the generator on the low- voltage side (The wind turbine 300 has a generator 302, a full scale power converter (inclusive of grid filter) 304 and a transformer (e.g. nacelle transformer) 306, multi-phase connection is shown in figure 3, paragraph [0090]); said program being configured, when executed by a processor, to: monitor a local voltage asymmetry value on the low-voltage side of the local transformer
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(during asymmetrical fault condition, the voltage seen at the LV side 308 of the transformer 306 has a non-zero positive sequence component and a non-zero negative sequence component. An example of a positive sequence component 402 and a negative sequence component 404 of the voltage at the LV side 308 of the transformer 306 are shown in FIG. 4. [0090]); and, compare, in a first comparing step, the monitored local voltage asymmetry value to a predetermined threshold voltage asymmetry value ([0098] FIG. 8 shows a flowchart 800 of a method for operating a power generation system coupled to a power grid during a grid unbalance event or a grid fault event. At 802, a power grid voltage is determined. At 804, a negative sequence grid voltage of the power grid is determined from the power grid voltage. At 806, the determined negative sequence grid voltage is compared with a reference voltage. In one embodiment, the reference voltage may be determined after 802 or 804 of the flowchart 800. At 808, a negative sequence reactive injection current for a possible injection by the power generation system into the power grid is determined based on the result of the comparison. Also see paragraph [0099]).
Gupta et al teaches an algorithm but does not explicitly teach a storage device comprising: a non-transitory computer readable medium having program code.
Grubic et al (US 2017/0176536 A1) teaches, [0033] FIG. 2 is a schematic view of an exemplary electrical power system 200 for wind turbine 100 (shown in FIG. 1). In the exemplary embodiment, electrical power system 200 converts the mechanical energy of rotor blades 112, low-speed shaft 134, gearbox 130, high-speed shaft 136, and generator 132 into electrical energy to transmit over grid bus 138 to the utility grid (not shown) through a transformer 202. Rotor blades 112 mechanically couple with gearbox 130 through low-speed shaft 134, and gearbox 130 mechanically couples with generator 132 through high-speed shaft 136. Electrical power system 200 further includes a controller 206 coupled in electronic data communication with power converter 204 to control the operation of power converter 204. In one embodiment, controller 206 is a portion of a separate, stand-alone unit from power converter 204. In an alternative embodiment, controller 206 is integrated with power converter 204. In the exemplary embodiment, generator 132 is a DFIG including a rotor 208, and a stator 210 magnetically coupled to rotor 208. [0039] The voltage measurement, processing, and display capabilities of electrical power system 200 form a fault detection system 228. As shown in FIG. 2, fault detection system includes acquisition connectors 220 and/or sensors 222, DAQ 218, and display 226. Alternatively, fault detection 228 is entirely contained within power converter 204 or controller 206. In this alternative embodiment, line contactors 216 perform the functions of acquisition connectors 220 and sensors 222, the processor (not shown) of power converter 204 or controller 206 performs the data acquisition and processing functions of DAQ 218, and display 226 can be disposed locally or remotely, by direct or wireless coupling).
Therefore it would have been obvious to one of the ordinary skill in the art before the effective filing date of the claimed invention, to have modified the teachings of Gupta et al (US 20130264824 A1) by providing a fault detection system for a wind turbine which includes a controller 206, display 226 and an alert indication as taught by Grubic et al ([0033], [0039], [0060]).
One of the ordinary skill in the art would have been motivated to make such a modification, when applied to a wind park that includes a plurality of wind turbines, the early warning advantages enable a repair/maintenance crew to prioritize wye-ring crack repairs of individual turbines in a desired order, according to which respective rotors exhibit fault indicators having the greatest magnitude, as taught by Grubic et al (paragraph [0076]).
Regarding independent claim 13, Gupta et al (US 2013/0264824 A1) teaches, A computer program product (algorithm in paragraphs [0081], [0184]) for identifying a defect in at least one electrical component of an energy installation connected to an electrical grid (a method for operating a power generation system coupled to a power grid during a grid fault event or a grid unbalance event paragraph [0001]), the computer program product being stored on a non-transitory computer readable medium (algorithm in paragraphs [0081], [0184], storage device and non-transitory medium are implicitly taught), the energy installation including: at least one generator unit having at least one multiple-phase generator configured for producing electrical energy and a multiple-phase local transformer with a low-voltage side and a high-voltage side fed by the generator on the low-voltage side (The wind turbine 300 has a generator 302, a full scale power converter (inclusive of grid filter) 304 and a transformer (e.g. nacelle transformer) 306, multi-phase connection is shown in figure 3, paragraph [0090]); wherein the program code is configured, when executed by a processor (algorithm in paragraphs [0081], [0184]), to: monitor a local voltage asymmetry value on the low-voltage side of the local transformer; and, compare, in a first comparing step, the monitored local voltage asymmetry value to a
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predetermined threshold voltage asymmetry value ([0098] FIG. 8 shows a flowchart 800 of a method for operating a power generation system coupled to a power grid during a grid unbalance event or a grid fault event. At 802, a power grid voltage is determined. At 804, a negative sequence grid voltage of the power grid is determined from the power grid voltage. At 806, the determined negative sequence grid voltage is compared with a reference voltage. In one embodiment, the reference voltage may be determined after 802 or 804 of the flowchart 800. At 808, a negative sequence reactive injection current for a possible injection by the power generation system into the power grid is determined based on the result of the comparison. Also see paragraph [0099]).
Gupta et al teaches an algorithm but does not explicitly teach a computer program product and wherein the program code is configured, when executed by a processor.
Grubic et al (US 2017/0176536 A1) teaches, ([0033] FIG. 2 is a schematic view of an exemplary electrical power system 200 for wind turbine 100 (shown in FIG. 1). In the exemplary embodiment, electrical power system 200 converts the mechanical energy of rotor blades 112, low-speed shaft 134, gearbox 130, high-speed shaft 136, and generator 132 into electrical energy to transmit over grid bus 138 to the utility grid (not shown) through a transformer 202. Rotor blades 112 mechanically couple with gearbox 130 through low-speed shaft 134, and gearbox 130 mechanically couples with generator 132 through high-speed shaft 136. Electrical power system 200 further includes a controller 206 coupled in electronic data communication with power converter 204 to control the operation of power converter 204. In one embodiment, controller 206 is a portion of a separate, stand-alone unit from power converter 204. In an alternative embodiment, controller 206 is integrated with power converter 204. In the exemplary embodiment, generator 132 is a DFIG including a rotor 208, and a stator 210 magnetically coupled to rotor 208. [0039] The voltage measurement, processing, and display capabilities of electrical power system 200 form a fault detection system 228. As shown in FIG. 2, fault detection system includes acquisition connectors 220 and/or sensors 222, DAQ 218, and display 226. Alternatively, fault detection 228 is entirely contained within power converter 204 or controller 206. In this alternative embodiment, line contactors 216 perform the functions of acquisition connectors 220 and sensors 222, the processor (not shown) of power converter 204 or controller 206 performs the data acquisition and processing functions of DAQ 218, and display 226 can be disposed locally or remotely, by direct or wireless coupling).
Therefore it would have been obvious to one of the ordinary skill in the art before the effective filing date of the claimed invention, to have modified the teachings of Gupta et al (US 20130264824 A1) by providing a fault detection system for a wind turbine which includes a controller 206, display 226 and an alert indication as taught by Grubic et al ([0033], [0039], [0060]).
One of the ordinary skill in the art would have been motivated to make such a modification, when applied to a wind park that includes a plurality of wind turbines, the early warning advantages enable a repair/maintenance crew to prioritize wye-ring crack repairs of individual turbines in a desired order, according to which respective rotors exhibit fault indicators having the greatest magnitude, as taught by Grubic et al (paragraph [0076]).
Closest Prior art
7. The following relevant prior art of record is not cited in the office action.
Jensen et al (US 2013/0128630 A1) teaches, a method of controlling the power input to a HVDC transmission link, which HVDC transmission link is connected to an AC power plant via a first voltage source converter and to AC grid via a second voltage source converter, which method includes using the second voltage source converter to perform voltage control of the HVDC transmission link during a no-fault mode of operation of the grid; monitoring a HVDC transmission link parameter to detect an unbalanced fault; and using the first voltage source converter to regulate the output of the AC power plant on the basis of the monitored HVDC transmission link parameter in the event of an unbalanced fault. Also described are a control module for controlling the power input to a HVDC transmission link; a voltage source converter for a power plant; and a power generation and transmission arrangement.
Wessels (US 2015/0365031 A) teaches, a method for controlling a wind turbine connected to a three-phase electrical supply grid during an asymmetrical grid fault. The method is configured for wind turbines with a doubly-fed induction generator. The reactive current to be fed into the electrical supply grid in the negative phase-sequence system is generated by the line-side and the rotor-side converter in a coordinated manner and depends on the line voltage. The reactive current to be fed into the electrical supply grid is distributed among the rotor-side and line-side converters. As a result, even in the case of severely asymmetrical grid faults, the reactive current to be fed into the electrical supply grid can be provided and excessive loading of the rotor-side converter can be prevented using simple means. The invention is also directed to a wind turbine for performing the above method.
Fortmann et al (US 2010/0052322 A1 ) teaches, A wind energy installation can include a generator which is driven by a rotor and generates electrical power in a multiphase manner for feeding into a network, a converter which is connected to the generator and to the network, and a control system which interacts with the converter and includes a negative sequence system regulation mechanism. The negative sequence system regulation mechanism can include a phase control module configured to determine an electrical variable of the negative sequence system according to the phase. Accordingly, an available current can be provided according to the operating situation for active power or idle power in the negative sequence system regulation mechanism. The negative sequence system regulation mechanism can thus help stabilize the network in the event of asymmetrical network conditions. Also, this relates to a correspondingly equipped wind park and an operating method.
Strafiel et al (US 2021/0184469 A1 ) teaches, a method for controlling a wind power installation and/or a wind farm having at least one wind power installation, particularly in the case of asymmetrical network voltages, comprising: measuring a first voltage of a first phase, a second voltage of a second phase and a third voltage of a third phase of a three-phase electrical system, calculating a symmetrical negative-sequence voltage system from the measured voltages including a first negative-sequence voltage, a second negative-sequence voltage and a third negative-sequence voltage, predefining setpoints for a negative-sequence current system depending on the calculated, symmetrical negative-sequence voltage system including a first negative-sequence current component, a second negative-sequence current component and a third negative-sequence current component, wherein the setpoints are defined such that a balancing of the measured voltages is achieved, feeding an asymmetrical three-phase AC current into a wind farm network or an electrical supply network depending on the predefined setpoints.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to SURESH RAJAPUTRA whose telephone number is (571) 270-0477. The examiner can normally be reached between 8:00 AM - 5:00 PM.
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/SURESH K RAJAPUTRA/Examiner, Art Unit 2858
/RISHI R PATEL/Primary Examiner, Art Unit 2858
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