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 .
This action is in response to an amendment filed on 09/29/2025.
Claims 1-15 are pending for examination.
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.
Claims 1-15 are rejected under 35 U.S.C. 102 (a) (1) as being anticipated by Shanghai et al. (CN 102,999,675 B and Shanghai hereinafter – English machine translation of record).
As to Claim 1, Shanghai in its teachings as shown in Fig.1-11 disclose a method of operating a power converter, wherein the power converter comprises a rotor side converter configured to be electrically coupled to a rotor of a wound rotor induction generator (see Fig.10, DFIG), wherein the method comprises:
operating the power converter in a grid forming operating mode (see Fig.1) in which the rotor side converter is operated to control an output voltage (see [0113]-[0114] and [0121] – [0128]) at a stator of the wound rotor induction generator in accordance with a reference stator voltage (see [0113] – [0114]), wherein operating the power converter in the grid forming operating mode comprises:
based on the reference stator voltage for the output stator voltage, deriving a reference rotor current for a rotor current in the rotor (see equations 5, 6 and 7 and also [0115] – [0118]); and
controlling the rotor current in the rotor in accordance with the reference rotor current (see also Fig. 7).
As to Claim 2, Shanghai disclose the method according to claim 1, wherein the rotor current is a three-phase rotor current, wherein the reference rotor current for the three-phase rotor current is derived in a rotating d-q frame which rotates with a phase angle and which includes a d component of the rotor current and a q component of the rotor current, and wherein the rotor current is controlled by a rotor current controller comprising a respective d component current controller and a respective q component current controller, and wherein at least one of the d-axis current controller and the q-axis current controller is a proportional-integral controller (see [0125] – [0126]).
As to Claim 3, Shanghai disclose the method according to claim 1, wherein controlling the output stator voltage comprises controlling an output stator voltage magnitude and/or controlling an output stator voltage phase (see Fig.7 and [0113]).
As to Claim 4, Shanghai disclose the method according to claim 3, wherein operating the power converter in the grid forming operating mode further comprises: determining a phase angle of the output stator voltage based on a swing equation in response to a reference torque and a monitored torque or in response to a reference active power and a monitored active power (see formula 2 and [0098] – [0100]).
As to Claim 5, Shanghai disclose the method according to claim 4, wherein the swing equation is a second order differential equation, wherein the second order differential equation models an inertial response, and wherein the second order differential equation is represented by an equation d(dθ/dt)/dt=1/(2H)(τ*−τ−D(ω.sub.0−ω)) or d(dθ/dt)/dt=1/(2H)(Ψ*−Ψ−D(ω.sub.0−ω)), wherein θ is the phase angle, H is an inertia coefficient, D is a damping coefficient, ω.sub.0 is a predetermined nominal frequency, ω is an electrical angular velocity, τ* is the reference torque, τ is the monitored torque, P* is the reference active power, P is the monitored active power (see formula 2 and [0098] – [0100]).
As to Claim 6, Shanghai disclose the method according to claim 4, wherein the method further comprises; applying a reference frame transformation based on the determined phase angle (θ), wherein the applying the reference frame transformation comprises at least one of transforming from the dq-frame into the abc-frame and transforming from the abc-frame into the dq-frame (see formula 2 and [0098] – [0100]).
As to Claim 7, Shanghai disclose the method according to claim 1, wherein deriving the reference rotor current from the reference stator voltage comprises
monitoring a stator current in stator windings of the stator to generate a monitored stator current, deriving a reference flux from the reference stator voltage, and
generating the reference rotor current based on the reference flux and the monitored stator current (see equations 3, 4 and 6 and also [0103] - [0110]).
As to Claim 8, Shanghai disclose the method according to claim 7, wherein, the reference flux is a reference stator flux and the reference rotor current is generated from the reference stator flux by a stator flux rotor current equation set, wherein the stator flux rotor current equation set comprises i* r,d=(Ψ*s,d−Lsis,d)/Lm and i*r,q (Ψ*s,q−Lsi s,q)/Lm wherein i*r,d is the reference rotor current in d axis, i*r,q is the reference rotor current in q axis, Ψ*s,d is the reference stator flux in d axis, Ψ*s,q is the reference stator flux in q axis, is,d is the monitored stator current in d axis, is,q is the monitored stator current in q axis, Lm is a magnetizing inductance and Ls is a stator inductance; or
wherein the reference flux is a reference rotor flux and the reference rotor current is generated from the reference rotor flux by a rotor flux rotor current equation set, wherein the rotor flux rotor current equation set comprises i*r,d=(Ψ* r,d−Lmis,d)/L.sub.r and i*r,q(Ψ*r,q−Lmis,q)/Lr, wherein i*r,d is the reference rotor current in d axis, i*r,q is the reference rotor current in q axis, Ψ*r,d is the reference rotor flux in d axis, Ψ*r,q is the reference rotor flux in q axis, is,d is the monitored stator current in d axis, is,q is the monitored stator current in q axis, Lm is the magnetizing inductance and Lr is a rotor inductance (see equations 3, 4 and 6 and also [0103]-[0110]).
As to Claim 9, Shanghai disclose the method according to claim 7, wherein the reference flux is a reference stator flux and deriving the reference flux comprises:
providing a reference reactive power, monitoring a reactive power to generate a monitored reactive power (Q), and generating the reference stator flux by a reactive power controller e based on the reference reactive power and the monitored reactive power (see equation 5 and [0108]).
As to Claim 10, Shanghai disclose the method according to claim 9, wherein the reactive power controller is cascaded by a voltage control and providing the reference reactive power further comprises: providing the reference stator voltage, monitoring the output stator voltage to generate a monitored stator voltage, and generating the reference reactive power by a voltage controller based on the reference stator voltage and the monitored stator voltage (see equation 5 and [0108]).
As to Claim 11, Shanghai disclose the method according to claim 7, wherein the reference flux is a reference rotor flux and providing the reference flux comprises:
providing a reference equivalent synchronous generator voltage, and generating the reference rotor flux based on the reference equivalent synchronous generator voltage, wherein, generating the reference rotor flux is based on an equation Ψ*r,d=E*eq/(ωg (Lm/Lr)), wherein Ψ*r,d is the reference rotor flux in d axis, E*eq is the reference equivalent synchronous generator voltage, ωg is a grid frequency, Lm is a magnetizing inductance, and Lr is a rotor inductance (see equation 5, [0108] and [0118]).
As to Claim 12, Shanghai disclose a control system for controlling the operation of the power converter comprising the rotor side converter configured to be electrically coupled to the rotor of the wound rotor induction generator, wherein the control system is configured to operate the power converter in the grid forming operating mode in which the rotor side converter is operated to control the output stator voltage at the stator of the wound rotor induction generator in accordance with the reference stator voltage, wherein the control system is configured to perform the method according to claim 1 (see [0114] – [0121]).
As to Claim 13, Shanghai disclose a power generation system comprising: the wound rotor induction generator comprising the rotor and the stator, wherein the stator is configured to be electrically coupled to a power grid, the power converter comprising the rotor side converter configured to be electrically coupled to the rotor of the wound rotor induction generator, and the control system according to claim 12, wherein the control system is coupled to the power converter to control the operation of the power converter (see Fig.11 and [0060]).
As to Claim 14, Shanghai disclose the power generation system according to claim 13, wherein the power converter further includes a grid side converter that is coupled to the rotor side converter, wherein the control system is configured to operate the grid side converter in a power grid following operation, wherein the grid following operation includes vector control or inertia synchronization control (see Fig.10 and also [0135]- [0137]).
As to Claim 15, Shanghai disclose a computer program product, comprising a computer readable hardware storage device having computer readable program code stored therein, said program code executable by a processor of a computer system to implement a method for controlling the operation of the power converter comprising the rotor side converter configured to be electrically coupled to the rotor of the wound rotor induction generator, wherein the computer program comprises control instructions which, when executed by a processing unit of a control system controlling the operation of the power converter, cause the processing unit to perform the method according to claim 1 (see Abstract and [0001]).
Response to Arguments/Remarks
As to applicant’s arguments as shown in pages 6-9 “…Applicant contends that claim 1 is not anticipated by Shanghai because Shanghai does not teach each and every element of claim 1... Moreover, document Shanghai fails to disclose a method of operating a power converter as claimed…Applicant contends that Shanghai fails to disclose operating the power converter in a grid forming operating mode as recited by claim 1, and instead only teaches conventional grid following operation with power control loops. The claimed method of controlling stator voltage according to a reference stator voltage is fundamentally different from Shanghai's power-controlled approach. Therefore, Shanghai does not anticipate the claimed subject matter. Claims 2-15 depend directly or indirectly from claim 1 and are allowable for at least the same reasons as claim 1, as they all require the grid forming operating mode that Shanghai fails to disclose…”
In response to applicant’s argument, the examiner respectfully disagrees with the applicant’s assertion. The examiner would also like to emphasize that the claims are examined enlight of the specification using the broadest reasonable interpretation (BRI) as cited in the previous office action of record. In addition, in contrary to applicant’s argument, Shanghai clearly teaches what is broadly claimed by the applicant in which power grid side transducer adopts the orientation of the stator voltage vector control scheme for controlling the AC-DC-AC frequency converter DC bus voltage and reactive power transmitted by the network-side inverter. power network side frequency converter control system adopts double closed loop structure; the outer ring is a DC voltage control loop, inner loop is a current control loop, as shown in FIG. 8 (see [0104]). Moreover, it is also thought that the dq converting module for converting the frequency modulation coefficient signal of lower stator flux orientation reference coordinate system output by the current controller is signal input of the double-fed motor rotor reference coordinate system in the DFIG; dq conversion module for converting the double-fed motor rotor current by the expression method of rotor reference coordinate system is converted into the expression method of stator flux orientation coordinate system so as to realize the rotor side converter for controlling the stator flux orientation; and DFGI module composed of an induction generator and rotor side converter model, the model equation and input and output are all under the rotor reference coordinate system representation, the output signal with a rotor current, Id, rotor position corner I and stator and rotor flux real part and imaginary (see also [0115] – [0118]). Hence, the claimed and argued limitations of independent claim 1 is anticipated by Shanghai and its respective dependent claims 2-15 remain rejected. In conclusion, applicant’s arguments/remarks filed on 09/29/2025 have been fully considered but they are not persuasive as shown above.
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 GABRIEL T AGARED whose telephone number is (571)270-1981. The examiner can normally be reached 8-5 (Mon- Thur).
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/GABRIEL AGARED/Primary Examiner, Art Unit 2846