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 .
Response to Arguments
Applicant's arguments filed July 21st, 2026 have been fully considered but they are not persuasive.
Applicant argues Cousineau regulates a switch position rather than a DC-link voltage or power and that Cousineau fails to teach the converter being a bidirectional converter. In response to applicant's arguments against the references individually, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986). In the combination made according to the rejection, the regulation is performed by the bi-directional DC-to-DC converter of Burra which is commanded by a controller to transfer a demanded power to or from the DC link (Burra, paragraphs 12, 15, 16); that is, an active, commanded regulation of a DC-link electrical quantity, not a mere change of circuit topology. Second, Cousineau discloses the charging path is not a bare on/off switch. The SCR’s, the current sensor, error amplifier, and gate drivers form a closed regulation loop that controls the charging sequence toward a defined charge level. The DC bus voltage passage was cited as the feedback input to that regulation, not as the regulation itself. Last, under broadest reasonable interpretation, the claim requires that the activating command cause the converter to regulate at least one of a voltage and power at the DC link such that energy is transferred. A converter commanded to draw a controlled charging power from the DC link regulates the power at the DC link within the plain meaning of the claim. The claim language does not require the regulation be “the primary control objective”.
Applicant argues Cousineau teaches a parallel-connected supercapacitor is a passive element that is monitoring the system rather than utilized for regulating and controlling it. This argument is not persuasive. The combination replaces the direct-parallel coupling of Cousineau with a converter-mediated coupling of Burra. The combination provides a system with the storage is no longer passively charging parallel element; charge and discharge are actively commanded through the interposed converter of Burra.
Applicant argues the converter of Burra serves grid-frequency stabilization and the actuator mode plays no role. This argument is not persuasive. The test for obviousness is not whether the features of a secondary reference may be bodily incorporated into the structure of the primary reference; nor is it that the claimed invention must be expressly suggested in any one or all of the references. Rather, the test is what the combined teachings of the references would have suggested to those of ordinary skill in the art. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981). In this instance, the rejection does not import the grid-frequency stabilization logic of Burra but instead adopts the converter-interposed storage topology while the operating mode dependent trigger remains supplied by Cousineau. The pitch processor of Cousineau already generates a charging-path command when the servo motor is being driven into a generator mode. Both references are directed to the same field of endeavor (energy storage coupled to a wind turbine DC link). Additionally, the articulated motivation is drawn from Burra (Paragraphs 15-16).
The rejections are maintained.
Claim Objections
Claim 9 is objected to because of the following informalities:
Claim 9 recites “wherein: wherein the first operating mode…” The duplication of the wherein should be corrected.
Appropriate correction is required.
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.
Claims 1-4, 6, 11-13, and 15 are rejected under 35 U.S.C. 103 as being unpatentable over Cousineau (WO 2007132303) in view of Burra (EP 2306001).
Regarding claims 1 and 11-12;
Cousineau discloses a method for controlling an electro-mechanical actuation system of a wind turbine (Figure 1), a controller and non-transitory computer-readable storage medium with a computer program stored thereon, and a processor (pitch control processor, an embedded or PLC type control system), the electro-mechanical actuation system including an electro-mechanical actuator configured to be connected to a DC link intermediate circuit (“a single electric motor is used to drive the blade pitch gearbox which in turn drives the blade pitch bearing”) and an energy storage unit connectable to the DC link intermediate circuit via a converter (“Super Capacitor energy storage bank connected in parallel with the Servo Amplifier DC bus”), the method comprising: providing first information which is representative of an operating mode of the electro-mechanical actuator, wherein the operating mode can either be a first operating mode or a second operating mode (“when the servo motor is being driven into a generator mode by the weight or counter balance of the blade during certain pitch activity”); and, if the operating mode is the second operating mode, generating an activating command for the converter (“The Pitch Processor allows a second method of battery charging, through the Regeneration Resistor control line. This is usually turned on when the servo motor is being driven into a generator mode”) which is configured to cause the converter to regulate at least one of a voltage and a power at the DC link intermediate circuit such that energy is transferred from the DC link intermediate circuit into the energy storage unit (“The level of capacitor charge is directly proportional to its voltage and is monitored by the Pitch Processor Control via the DC Bus Voltage Sense input line”). The “computer program” and its respective instructions are provided above in the method steps (“Pitch Control Processor, an embedded or PLC type control system” which includes the instructions and non-transitory computer-readable storage medium).
Cousineau fails to teach the converter being a bidirectional converter.
Burra teaches a multi-use energy storage for renewable sources, the system connects the storage devices to a DC link by a bidirectional converter (“The system 40 further includes one or more energy storage devices 54 which are coupled to the DC link 46 via one or more respective bidirectional DC to DC converters 56”).
Because Cousineau and Burra both are directed to energy storage systems for wind turbine applications through DC bus architecture, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the system architecture of Cousineau such that the converter is a bidirectional converter as taught by Burra for the purposes of enabling flow from the DC link to the energy storage device to the DC link, thereby providing improved energy recovery during regeneration events and power assist during high demand motoring.
Regarding claim 2, Cousineau in view of Burra teaches the method according to claim 1 above. Cousineau as modified by Burra further teaches the first operating mode is an electrical power consuming mode of the electro-mechanical actuator, and the second operating mode is an electrical power generating mode of the electro-mechanical actuator (“when the servo motor is being driven into a generator mode” explicitly identifies the power generating mode; the power consuming mode is the pitching mode of the servo motor; Cousineau), the method further comprising: providing second information which is representative of one of an actual voltage and an actual power at the DC link intermediate circuit (“monitored by the pitch processor control via the DC bus voltage sense input line”; Cousineau); determining third information (Burra: DC link voltage setpoint) in dependence upon the second information, wherein the third information is an operating information for the converter and is representative of one of a DC link voltage setpoint and a DC link power setpoint (Cousineau as modified by Burra: pitch processor monitors voltage and controls charging based on capacitor charge level; error amplifier compares actual to a setpoint), wherein, for the second operating mode, the third information is based on one of: the DC link voltage setpoint is lesser than the actual voltage of the DC link intermediate circuit (Cousineau as modified by Burra: in generator mode, the regenerated energy raised DC bus voltage above nominal, and charging brings it down).
Regarding claim 3, Cousineau in view of Burra teaches the method according to claim 2 above. Cousineau as modified by Burra further teaches the converter is operated according to the third information, the voltage a at the DC link intermediate circuit is regulated by the converter until the DC link voltage setpoint is attained, by transferring energy from the DC link intermediate circuit to the energy storage unit, thus charging the energy storage unit up (the SCR’s along with the DC current measurement (current sensor) is used in a standard ‘off the shelf’ arrangement of error amplifier and gate driver…to control the charging sequence; there is then a loop control until the setpoint is reached).
Regarding claim 4, Cousineau in view of Burra teaches the method according to claim 2 above. Cousineau further discloses providing fourth information (minimum predefined voltage) which is representative of a minimum predefined voltage at the DC link intermediate circuit (pitch processor monitors voltage levels with defined thresholds for charging control), wherein: if the operating mode is the second operating mode, the activating command is only generated if a comparison between the fourth information and the second information reveals one of the following: the actual voltage is above the minimum predefined voltage (pitch processor monitors voltage via DC bus voltage sense input line and controls charging; charging (activating command) would only be beneficial when the DC bus voltage is above the minimum level where regenerating energy is available; below the minimum voltage, there is no excess energy to transfer to storage).
Regarding claim 6, Cousineau in view of Burra teaches the method according to claim 4 above. Cousineau further discloses the DC link intermediate circuit has a first side and a second side and is connectable to a first converter (rectifier D1-D6) on the first side and to a second converter (servo amplifier) on the second side; the DC link intermediate circuit is configured to be powered from a supply grid via the first converter; and, the DC link intermediate circuit is configured to be connected to the electro-mechanical actuator via the second converter (first converter being at the grid and the second converter at the actuator; “a three-phase bridge rectifier D1-D6” (first side) and “servo amplifier supplying three phase AC power that drives said AC motor” (second side)); the method further comprising: providing sixth information which is representative of one of a rectified supply grid voltage (rectified supply grid voltage and grid current load power; when not in regeneration mode, the DC bus voltage corresponds to the rectified grid voltage; see Page 4, Line 33 – Page 5, Line 30); wherein, if the operating mode is the second operating mode: the third information is also determined in dependence upon the sixth information so that: the DC link voltage setpoint is greater than the rectified supply grid voltage (Page 14, Line 6 to Page 15, Line 21); and, the fourth information (charging information) is also determined in dependence upon the sixth information so that one of: the minimum predefined voltage is greater than the rectified supply grid voltage (energy storage operates at voltage above the grid-rectified baseline; minimum predefined voltage as a threshold below which charging is not triggered: the super capacitor bank operate between 150V and 250V, and the minimum predefined voltage must be set above whatever baseline voltage the rectified grid would provide to the super capacitor circuit; the voltage level operation is then distinct form the main rectified gris bus, thereby ensuring charging activation responds only to regenerative events, not normal grid fluctuations).
Regarding claim 13;
Cousineau discloses an electro-mechanical actuation system for a wind turbine (Figure 1), the electro-mechanical actuation system comprising: a first converter (three phase AC power is rectified by a three phase bridge rectifier D1-D6) connected to a supply grid (three-phase electrical grid power); a DC link intermediate circuit (servo amplifier DC bus) having a first side, said DC link intermediate circuit being connected on said first side to said first converter (D1-D6 outputs to the DC bus) and configured to be powered from the supply grid via said first converter (servo amplifier powered by three-phase electrical power drives an AC motor); a converter (“Super Capacitor energy storage bank connected in parallel with the Servo Amplifier DC bus”), an electro-mechanical actuator (AC motor that changes the pitch of the rotor blades); an energy storage unit (super capacitor type energy storage) connected to said DC link intermediate circuit via said converter; a controller having a processor and a non-transitory computer readable medium having a computer program including a plurality of instructions stored thereon (pitch control processor an embedded or PLC type control system); wherein the plurality of instructions are configured, when the computer program is executed by the processor, to cause the controller to: provide first information which is representative of an operating mode of the electro-mechanical actuator, wherein the operating mode can either be a first operating mode or a second operating mode (pitch mode or generator mode); and, i if the operating mode is the second operating mode, generating an activating command for the converter (“The Pitch Processor allows a second method of battery charging, through the Regeneration Resistor control line. This is usually turned on when the servo motor is being driven into a generator mode”) which is configured to cause the converter to regulate at least one of a voltage and a power at the DC link intermediate circuit such that energy is transferred from the DC link intermediate circuit into the energy storage unit (“The level of capacitor charge is directly proportional to its voltage and is monitored by the Pitch Processor Control via the DC Bus Voltage Sense input line”); the electro-mechanical actuator being connected to the DC link intermediate circuit (the servo amplifier (connected to the DC bus) drives the AC motor, placing the actuator on the second side opposite the grid rectifier); the controller being configured to control the converter according to the activating command (the pitch processor control regulates the charging system by switching between charge and operate); and, the converter being configured to regulate a voltage at the DC link intermediate circuit upon reception of the activating command such that energy is transferred from the DC link intermediate circuit into the energy storage unit (“the level of capacitor charge is directly proportional to its voltage and is monitored by the pitch processor control via the DC bus voltage sense input line”).
Cousineau fails to teach the converter which is bidirectional.
Burra teaches a multi-use energy storage for renewable sources, the system connects the storage devices to a DC link by a bidirectional converter (“The system 40 further includes one or more energy storage devices 54 which are coupled to the DC link 46 via one or more respective bidirectional DC to DC converters 56”).
Because Cousineau and Burra both are directed to energy storage systems for wind turbine applications through DC bus architecture, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the system architecture of Cousineau such that the converter is a bidirectional converter as taught by Burra for the purposes of enabling flow from the DC link to the energy storage device to the DC link, thereby providing improved energy recovery during regeneration events and power assist during high demand motoring.
Regarding claim 15, Cousineau in view of Burra teaches the system according to claim 13 above. Cousineau further discloses a first measuring device connected to the DC link intermediate circuit and configured to measure an actual voltage of the DC link intermediate circuit (“monitored by the pitch processor control via the DC bus voltage sense input line”); and, a second measuring device connected to the energy storage unit and configured to measure an actual charging voltage of the energy storage unit (the level of capacitor charge is directly proportional to its voltage and is monitored by the pitch processor control).
Claims 5, 7-9, and 14 are rejected under 35 U.S.C. 103 as being unpatentable over Cousineau (WO 2007132303) in view of Burra (EP 2306001), and further in view of Becker (US 20120169051).
Regarding claim 5;
Cousineau in view of Burra teaches the method according to claim 2 above. Cousineau further discloses an energy dissipating element is connectable to the DC link intermediate circuit (the pitch processor allows a second method of battery charging through the regeneration resistor control line).
Cousineau fails to teach providing fifth information which is representative of one of an upper threshold voltage of the DC link intermediate circuit and an upper threshold power of the DC link intermediate circuit; wherein, if the operating mode is the second operating mode, the activating command is only generated if the comparison between the second information and the fifth information reveals at least one of: the actual voltage of the DC link intermediate circuit is below the upper threshold voltage, and, the actual power of the DC link intermediate circuit is below the upper threshold power; and, wherein a chopper command is generated if the operating mode is the second operating mode and if the comparison between the second information and the fifth information reveals at least one of: the actual voltage of the DC link intermediate circuit is equal to or above the upper threshold voltage, and, the actual power of the DC link intermediate circuit is equal to or above the upper threshold power; and, wherein the chopper command is configured to cause energy transfer from the DC link intermediate circuit to the energy dissipating element.
Becker teaches an adjustment device for blade pitch adjustment systems for wind energy with a DC link circuit. Becker further teaches an upper threshold voltage (Paragraphs 63 and 70; overvoltage protection requires an upper threshold voltage to trigger), and an overvoltage condition detection (“if the motor is operated such that it increases the voltages at the outputs, this leads to a reverse current flow and to an overvoltage at terminals”; Paragraph 47). With the overvoltage protection, normal charging (activating command) only occurs when the voltage is below the overvoltage threshold; when above the threshold, the system enters protective dissipation mode rather than charging mode. The voltage is dissipated by regularly opening and closing the switch S7; “regularly opening and closing” is considered a chopper operation and is triggered when overvoltage conditions exist. The chopper command is configured to cause energy transfer from the DC link to the energy dissipating element (“A series circuit comprising the switches S1 and S4, a series circuit comprising the switches S3 and S6, a series circuit comprising switches S5 and S2, and a series circuit comprising the switch S7, and the resistor”; energy is then dissipated by resistor R).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the method of Cousineau such that providing fifth information which is representative of an upper threshold voltage of the DC link intermediate circuit; wherein, if the operating mode is the second operating mode, the activating command is only generated if the comparison between the second information and the fifth information reveals: the actual voltage of the DC link intermediate circuit is below the upper threshold voltage; and, wherein a chopper command is generated if the operating mode is the second operating mode and if the comparison between the second information and the fifth information reveals: the actual voltage of the DC link intermediate circuit is equal to or above the upper threshold voltage; and, wherein the chopper command is configured to cause energy transfer from the DC link intermediate circuit to the energy dissipating element as taught by Becker for the purposes of providing precise energy dissipation and improved safety to prevent overvoltage damage.
Regarding claim 7;
Cousineau in view of Burra teaches the method according to claim 1 above. Cousineau further discloses providing seventh information which is representative of one of a nominal charging voltage of the energy storage unit (250V is the target nominal charging voltage), providing eighth information which is representative of an actual charging voltage of the energy storage unit (level of capacitor charge is directly proportional to its voltage and is monitored by the Pitch Processor Control), the activating command is only generated if the actual charging voltage does not exceed the nominal charging voltage by more than a critical voltage threshold (Cousineau monitors the capacitor charge level and controls charging via the pitch processor; the system prevents overcharging beyond the rated voltage (300V per the calculation section) to avoid damage to the super capacitor(s); 150-250 is the operating range for safe operating limits).
Cousineau fails to teach a chopper command is generated if the operating mode is the second operating mode and if the comparison between the seventh information and the eighth information reveals at least one of: the actual charging voltage of the energy storage unit exceeds the nominal charging voltage by more than the critical voltage threshold, and, the actual charging power of the energy storage unit exceeds the nominal charging power by more than the critical power threshold; and, wherein said chopper command is configured to cause the transfer of energy from the DC link intermediate circuit to an energy dissipating element.
Becker teaches a chopper command is generated if the operating mode is the second operating mode and if the comparison between two sets of information reveals that the actual charging voltage of the energy storage unit exceeds the nominal charging voltage more than the critical voltage threshold (the voltage is dissipated by regularly opening and closing the switch S7; when the overvoltage condition exists (storage full, can’t accept more charge), the chopper activates to dissipate the excess energy), and the chopper command is configured to cause an energy transfer from a circuit to an energy dissipating element (a series circuit comprising the switch S7 and the resistor R; the resistor R is the energy dissipating element and the voltage is dissipated).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the method of Cousineau such that a chopper command is generated if the operating mode is the second operating mode and if the comparison between the seventh information and the eighth information reveals the actual charging voltage of the energy storage unit exceeds the nominal charging voltage by more than the critical voltage threshold; and, wherein said chopper command is configured to cause the transfer of energy from the DC link intermediate circuit to an energy dissipating element as taught by Becker for the purposes of providing precise energy dissipation and improved safety to prevent overvoltage damage.
Regarding claim 8, Cousineau in view of Burra and Becker teaches the method according to claim 7 above. Cousineau as modified by Burra and Becker further teaches a discharging command is generated if the first operating mode and actual charging is above the nominal (Burra: “the transient power or the temporary power boost may be increased by five to ten percent for up to ten seconds”; during high demand motoring (first operating mode), when the storage has excess charge (above nominal), the energy is discharged to assist the discharge during high demand; Burra: “converter 56 then provides the demanded transient power to the DC link from the energy storage device”; the bidirectional converter discharges storage to the DC link during power consuming transients). Additionally, Cousineau as modified by Burra and Becker teaches the transfer energy from the energy storage unit to the electro-mechanical actuator via the DC link (Burra: “converter 56 then provides the demanded transient power to the DC link from the energy storage device”; the energy flows from storage [Wingdings font/0xE0]converter[Wingdings font/0xE0]DC link[Wingdings font/0xE0]actuator). Thus, the combination of Cousineau and Burra teaches the bidirectional converter discharge capability.
Regarding claim 9, Cousineau in view of Burra and Becker teaches the method according to claim 8 above. Cousineau as modified by Burra further teaches the first operating mode is an electrical power consuming mode of the electro-mechanical actuator, and the second operating mode is an electrical power generating mode of the electro-mechanical actuator (“when the servo motor is being driven into a generator mode” explicitly identifies the power generating mode; the power consuming mode is the pitching mode of the servo motor; Cousineau), the method further comprising: providing second information which is representative of one of an actual voltage and an actual power at the DC link intermediate circuit (“monitored by the pitch processor control via the DC bus voltage sense input line”; Cousineau); determining third information (Burra: DC link voltage setpoint) in dependence upon the second information, wherein the third information is an operating information for the converter and is representative of one of a DC link voltage setpoint and a DC link power setpoint (Cousineau as modified by Burra: pitch processor monitors voltage and controls charging based on capacitor charge level; error amplifier compares actual to a setpoint), wherein, for the second operating mode, the third information is based on one of: the DC link voltage setpoint is lesser than the actual voltage of the DC link intermediate circuit (Cousineau as modified by Burra: in generator mode, the regenerated energy raised DC bus voltage above nominal, and charging brings it down). Cousineau as modified by Burra further teaches the converter is operated according to the third information, the voltage a at the DC link intermediate circuit is regulated by the converter until the DC link voltage setpoint is attained, by transferring energy from the DC link intermediate circuit to the energy storage unit, thus charging the energy storage unit up (the SCR’s along with the DC current measurement (current sensor) is used in a standard ‘off the shelf’ arrangement of error amplifier and gate driver…to control the charging sequence; there is then a loop control until the setpoint is reached).
Regarding claim 14;
Cousineau in view of Burra and Becker teaches the system according to claim 13 above. Cousineau further discloses a second converter connected to a second side of the DC link intermediate circuit (see claim 1 of Cousineau; the servo amplifier includes an inverter connected to the DC bus and outputting to the motor).
Cousineau fails to teach a braking resistor connected to the DC link intermediate circuit via a switching module being communicatively coupled to the controller.
Becker further teaches a braking resistor as part of the circuit (“ a series circuit comprising the switch S, and the resistor R) connected via a switching module (resistor R connected to switch S, the switching module connecting the resistor to the DC link intermediate circuit) and the switching module being communicatively coupled to the controller (each of the switches is controlled by a pulse width modulated signal; the inverter has a multiplicity of switches which are each provided between a node on the DC voltage side and a node on the AC voltage side).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the system of Cousineau such that a braking resistor connected to the DC link intermediate circuit via a switching module being communicatively coupled to the controller as taught by Becker for the purposes of providing a controlled energy dissipation, enabling precise energy management when storage is full or during overvoltage conditions, improving system reliability and component protection.
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JUSTIN D SEABE whose telephone number is (571)272-4961. The examiner can normally be reached Monday-Friday, 9:00-5:30.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Nathaniel Wiehe can be reached at 571-272-8648. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/JUSTIN D SEABE/Primary Examiner, Art Unit 3745
