DETAILED ACTION
Status of Claims
This action is in reply to the application filed on July 11, 2023.
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claims 1-15 are currently pending and have been examined.
Claims Objection
Claims 1-15 are objected to under 37 CFR 1.75(d)(1) as being of improper form because each claim limitation ends with a comma, whereas each should end with a semicolon, except for the last limitation which should end with a period. Applicant is required to correct the punctuation of claims 1-15 so that each limitation ends with a semicolon, and the final limitation ends with a period.
The requirement for proper punctuation in claims is addressed in MPEP § 608.01(m):
“Each claim begins with a capital letter and ends with a period. Where a claim sets forth a plurality of elements or steps, each element or step of the claim should be separated by a line indentation or start a new line, and the elements or steps should be separated by semicolons.”
Claim Rejections - 35 USC § 101
35 U.S.C. 101 reads as follows:
Whoever invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof, may obtain a patent therefor, subject to the conditions and requirements of this title.
Claim 15 is directed to non-statutory subject matter. The claim(s) does/do not fall within at least one of the four categories of patent eligible subject matter because claim 15 recites “A computer program product comprising instructions…”
A computer program product is not inherently limited to a non-transitory computer-readable storage medium. Under current USPTO practice, if the broadest reasonable interpretation of a computer-readable medium or computer program product encompasses a transitory propagating signal, the claim may be considered to encompass non-statutory subject matter under § 101.
Here, claim 15 does not recite: “non-transitory computer-readable storage medium” or equivalent language. The specification at paragraph [0037] similarly states: “The present invention relates to a computer program product comprising instructions which, when the program is executed by a computer, cause the computer to carry out an embodiment of the method disclosed herein.”
The provided specification text does not appear to expressly define the computer program product as non-transitory or as a physical storage medium.
Recommended amendment:
Claim 15: “A non-transitory computer-readable storage medium having instructions stored thereon, wherein said instructions, when executed by one or more processors, cause the one or more processors to perform the steps of the method according to claim 1.”
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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1, 3, and 14-15 are rejected under 35 U.S.C. 103 as being unpatentable over Häkli et al. (US 2020/0136544 A1).
Regarding Claims 1, 3, 14, and 15: Häkli teaches a method for estimating electrical parameters of an electric motor and a power filter connected to a power converter, the method comprising:
injecting an AC signal of different frequencies for a given time window in the power filter and the motor (“… a frequency sweep with a low voltage magnitude is applied to the motor(s) over a specified frequency range (e.g. 300-5000 Hz). The current resulting from the applied frequency sweep is then measured.” See ¶¶ 13, 39 & 36, & fig.4), (“Applying a small signal frequency sweep may comprise applying a low voltage magnitude signal … to the motor over a frequency range …” ¶ 16).
measuring a response signal of the power filter and the motor to the injected AC signal, (“The current resulting from the applied frequency sweep is then measured.”; “… measured current plotted on the y-axis …” See ¶¶ 39, 36, 37, & Figs. 4, 6, 7).
determining a resonance frequency of the power filter based on the measured response signal, (“The current noticeably peaks at the resonant frequency allowing detection of the resonant frequency …”; “… each of the current plots … shows a similar resonance response, with the resonant current occurring at close to 75 ms. Thus, the frequency output … at time t=75 ms gives the electrical resonant frequency …”) See ¶¶ 38-49, & Figs. 5, 6, 7).
Häkli does not explicitly disclose calculating a ratio of the two values, leakage inductances of the power filter and the motor.
However, Häkli teaches “one parameter is the resonance frequency of the output filter 22 in combination with the cable and motor impedances. This resonance frequency depends, amongst other things, on motor cable length(s) and motor impedance(s) which can vary quite a lot depending on motor types” (¶ 31).
“…each of the current plots 71 to 75 shows a similar resonance response, with the resonant current occurring at close to 75 ms. Thus, the frequency output of the ASD 4 of the motor drive system 20 at time t=75 ms gives the electrical resonant frequency of the system 20.”“The different frequency responses shown in the plot 80 are caused by, and can be used to measure, the impact of saturation of inductors in the motor drive system 20.” (¶¶ 44 & 48).
“At step 52 of the algorithm 40, a number of variables of the system are determined or defined. These might include one or more of minimum, optimum and maximum switching frequencies for the system 20. These might also include parameters for control set to ensure stable operation for this specific system resonance frequency.” (¶ 49).
“In one form of the invention, an optimum switching frequency for the system 20 may be set at a predetermined multiple of the resonance frequency detected during the step 46 of the algorithm 40. By way of example, a frequency of three times the resonant frequency could be set. … such that the effect of saturation of the inductances in the motor system 20 are taken into account. Thus, it may be advantageous if the instances of the frequency sweep steps 44 occur over a range of DC magnetization levels that might reasonably be expected to occur during the operation of the motor system 20.” (¶ 50).
“The different frequency responses shown in the plot 80 are caused by, and can be used to measure, the impact of saturation of inductors in the motor drive system 20.” (¶¶ 47 & 48).
Therefore, Häkli repeatedly teaches that the frequency sweep is used to determine resonance frequencies that are functions of both the filter and motor impedances (which include their respective leakage inductances). By varying the DC magnetization level (¶¶ 47 & 48), the method enables separation of the effects of the filter and motor inductances, since the inductor saturation (primarily in the motor) shifts the resonance, allowing the user to “measure the impact of saturation of inductors in the motor drive system 20.”
At step 52 (¶ 49), the system determines “a number of variables,” which by context includes the inductances of the filter and the motor, since these are the key variables that affect the resonance and are necessary for setting the “parameters for control set to ensure stable operation for this specific system resonance frequency.”
Häkli does not explicitly state “calculate the leakage inductance of the filter” or “calculate the leakage inductance of the motor” in those exact words, but it is clear from the technical context, the discussion of resonance frequency dependence, and the measurement of changes due to inductor saturation, that both values are being determined (or are determinable) from the data.
It would have been obvious to a person of ordinary skill in the art at the time of the invention to calculate the ratio of the filter leakage inductance to the motor leakage inductance in view of Häkli’s explicit teaching of separately determining both values. Once both the filter and motor leakage inductances are known, calculating their ratio is a simple mathematical operation (division) that would have been within the ordinary skill in the art.
Calculating the ratio of two system parameters (such as filter and motor leakage inductances) is a common and routine practice in the field of electrical engineering and motor drive diagnostics. The ratio provides a normalized measure of the relative contribution of the filter and the motor to the overall system inductance, which can be useful for system characterization, control tuning, diagnostics, or for compensating system behavior. In particular, as Häkli teaches determining both values for the purpose of system adaptation and control (¶¶ 50-51), one of ordinary skill would be motivated to also consider their ratio to further enhance diagnostics or to enable normalized comparisons across different systems or operating conditions.
Regarding Claim 3: Häkli teaches the method according to claim 1, wherein the method is carried out while the power filter is connected to the motor (¶¶ 15, 35, 36, 39, 46, & 53, Figs. 3, 4, 6, 7).
Claims 2, 4, 6, 8, and 12 are rejected under 35 U.S.C. 103 as being unpatentable over Häkli et al. (US 2020/0136544 A1) in view of Nalakath (US 2020/0358385 A1).Regarding Claim 2: Häkli substantially discloses the claimed invention but does not appear to explicitly teach if no resonance frequency of the power filter is determined, only estimate motor parameters. However, Nalakath describes a commissioning method for both synchronous and asynchronous motors, with the ability to select which parameters to estimate based on system configuration—if only the motor is present, only motor parameters are estimated (¶¶ 86-88).
Regarding Claim 4: Häkli substantially discloses the claimed invention but does not appear to explicitly teach sum of leakage inductances (filter + motor) by small-signal step voltage test at DC offset. However, Nalakath discloses the use of a DC ramp/step excitation to extract the sum of stator and leakage inductances, and explains how the test is performed at a set DC bias (¶¶ 45, 53, 57).
Regarding Claim 6: Häkli substantially discloses the claimed invention but does not appear to explicitly teach wherein a ratio of motor/filter leakage inductances is measured by using injected AC signal at DC offset. However, Nalakath describes extracting both leakage inductances using AC and DC tests; calculating their ratio is an obvious, routine mathematical step once both are known (¶¶ 47, 53, 58).
Regarding Claim 8: Häkli substantially discloses the claimed invention but does not appear to explicitly teach wherein further electrical parameters are calculated based on the ratio of leakage inductances of the power filter and the motor, wherein the further electrical parameters are selected from the following list: stator resistance (Rs), rotor resistance (Rr), motor leakage inductance (Lσ), magnetizing inductance (Lh), capacitance (Cf), and filter inductance (Lf), wherein the capacitance (Cf) is also estimated for each phase individually to consider unbalanced cases of capacitance. However, Nalakath teaches estimation of Rs, Rr, Lσ, Lh, and shows how per-phase analysis is possible via the test sequences (¶¶ 45, 57, 87, 88).
Regarding Claim 12: Häkli substantially discloses the claimed invention but does not appear to explicitly teach wherein a DC test is used for measuring stator resistance (Rs) and filter resistance (Rf) parameters, a step test is used for measuring motor leakage inductance (Lσ) und filter induction (Lf) parameters at four DC biases, AC tests are used for measuring magnetizing inductance (Lh) and rotor resistance (Rr) parameters, wherein the step test is performed with a current target of predefined percentage of a nominal magnetization current, wherein from the step test and the AC tests, the nominal magnetizing current is identified, wherein the AC signal of different frequencies is injected only once at a de bias equal to the identified nominal magnetizing current, and wherein the step test is rerun at the nominal magnetizing current with a current target of predefined percentage of nominal motor current, such that the result of the rerun step test is the sum of motor leakage and filter inductances. However, Nalakath teaches a comprehensive suite of DC, step, and AC tests for extracting all the listed parameters (¶¶ 45, 57, 58, 87, 88).
Claims 5 and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Häkli et al. (US 2020/0136544 A1) in view of Glibbery (US 2021/0021221 A1).Regarding Claim 5: Häkli substantially discloses the claimed invention but does not appear to explicitly teach numerical filter to remove LC resonance from step test signal. However, Glibbery teaches applying digital filtering and inverse filtering to voltage/current signals to isolate parameters and remove confounding effects such as resonance (¶¶ 111-116).
Regarding Claim 13: Häkli substantially discloses the claimed invention but does not appear to explicitly teach ESR of filter capacitor determined by peak at resonant frequency.
However, Glibbery teaches using frequency response and resonance analysis to extract equivalent series resistance (ESR) from resonance peak characteristics (¶¶ 80, 84, 85, 114, 115).
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Häkli et al. (US 2020/0136544 A1) in view of da Silva (US 2017/0063268 A1).
Regarding Claim 7: Häkli substantially discloses the claimed invention but does not appear to explicitly teach wherein the injection of the AC signal of different frequencies covers a frequency range within a minimum frequency up to a maximum frequency, and is monotonical increased or decreased, or random, or a given order, and covers an entire range with a given step-size. However, da Silva describes frequency response analysis using sweeps over a frequency range, with user-definable frequency arrays and step sizes (¶¶ 52-54, Figs. 5, 6, 8).
Claims 9-11 are rejected under 35 U.S.C. 103 as being unpatentable over Häkli et al. (US 2020/0136544 A1) in view of Jayaraman (US 2024/0186922 A1).
Regarding Claim 9: Häkli substantially discloses the claimed invention but does not appear to explicitly teach wherein the further electrical parameters are used to adjust control parameters for controlling the motor and/or the power filter. However, Jayaraman teaches using estimated parameters for health monitoring, control, and adaptation (¶¶ 9 & 14-18).
Regarding Claim 10: Häkli substantially discloses the claimed invention but does not appear to explicitly teach wherein the adjustment of the control parameters is carried out periodically and/or in response to a user command. However, Jayaraman describes periodic or event-driven adjustment of control parameters based on health monitoring and parameter estimation (¶¶ 33, 34, 111, 112).
Regarding Claim 11: Häkli substantially discloses the claimed invention but does not appear to explicitly teach wherein a degradation level of the power filter component parameters, capacitances, inductances and resistances (LC or LCL) are periodically compared at different time moments against different given thresholds. However, Jayaraman describes logging and comparing parameters over time for health monitoring and maintenance scheduling (¶¶ 34 & 111-112).
Conclusion
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/FAHD A OBEID/Supervisory Patent Examiner, Art Unit 3627
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