PTAB

IPR2017-01134

Gridco Inc v. VaRenTec Inc

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Systems And Methods For Edge Of Network Voltage Control Of A Power Grid
  • Brief Description: The ’922 patent describes a system for regulating voltage on a power distribution network. The system uses multiple shunt-connected, switch-controlled Volt-Ampere Reactive (VAR) sources placed at or near the network's edge, which use predetermined, non-equal time delays to control their switching operations and prevent system instability.

3. Grounds for Unpatentability

Ground 1A: Obviousness over D'Aquila and the Green Book - Claims 1-2, 8-10, and 15-16 are obvious over D'Aquila in view of the Green Book.

  • Prior Art Relied Upon: D'Aquila (Patent 5,402,057) and the Green Book (Electric Utility Engineering Reference Book: Volume 3: Distribution Systems).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that D'Aquila discloses nearly every element of the challenged claims, including a power distribution network with VAR sources located near loads to regulate voltage. D'Aquila teaches a system that monitors voltage and switches shunt reactances (capacitors) to keep load voltage constant. However, while D'Aquila recognizes the need for time delays to prevent "hunting" (undesired, rapid switching), it does not detail the specific mechanism. Petitioner asserted that the Green Book, a foundational reference in power distribution engineering, remedies this by explicitly teaching the use of coordinated, predetermined, and unequal time delays for multiple voltage regulators (including switched capacitors) to prevent the exact problem of "hunting" or "pumping."
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSA), starting with D'Aquila's system and its recognized need to avoid "hunting," would be directly motivated to consult a standard industry reference like the Green Book. The Green Book provides the well-known and detailed solution—using definite, unequal time delays—to solve the precise problem identified in D'Aquila.
    • Expectation of Success: Petitioner contended that combining the known time-delay coordination techniques from the Green Book with the voltage regulation system of D'Aquila was a straightforward application of established principles in the predictable field of electrical engineering, carrying a high expectation of success.

Ground 2A: Obviousness over the Green Book and NoMAX - Claims 1-2, 8-10, and 15-16 are obvious over the Green Book in view of NoMAX.

  • Prior Art Relied Upon: The Green Book and NoMAX (NoMAX® Instruction manual 900 Series Switched Capacitor Controls ©2007).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner asserted that the Green Book teaches the fundamental system for voltage regulation, including the use of switched shunt capacitors placed near loads and the necessity of using definite, unequal time delays to prevent "pumping." The Green Book, published in 1965, describes implementing these functions with older control circuits. NoMAX is an instruction manual for a modern, commercially available, microprocessor-based controller for switched capacitor banks. It explicitly teaches a "voltage control mode" that performs the functions of the claimed processor, including monitoring proximate voltage, waiting for a user-settable, predetermined time delay, and then switching the capacitor bank.
    • Motivation to Combine: A POSA tasked with implementing the voltage regulation and coordination scheme described in the Green Book would have been motivated to use a modern, processor-based controller. Petitioner argued it would be obvious to replace the outdated control circuits described in the Green Book with a modern, off-the-shelf digital controller like NoMAX to achieve the same functions with greater precision and flexibility. This constitutes a simple substitution of a known, modern equivalent for an older technology to achieve a predictable result.
    • Expectation of Success: Implementing the well-understood control logic from the Green Book using a modern processor-based system from NoMAX would be a routine design choice for a POSA, with a clear and predictable outcome.

  • Additional Grounds: Petitioner asserted additional obviousness challenges, including combining D'Aquila and NoMAX (Ground 3A). It also presented grounds adding IEEE SVC, a technical paper on Static Var Compensation, to the primary combinations to teach specific delay schemes for claim 3 (Grounds 1B, 2B, and 3B), such as having delays for two VAR sources be equal while a third is different.

4. Key Claim Construction Positions

  • "at or near the edge of the distribution power network": Petitioner argued this term should be construed to mean "on that portion of the power distribution network that is closer to the load that is to receive power than to the substation serving that load, which portion may be on a medium voltage portion or low voltage portion of a distribution feeder." This construction, based on the specification and file history, was argued to be broad enough to cover placement on primary (medium voltage) feeders, which is where the prior art often placed such devices.
  • "non-continuously monitor the proximate voltage": For the purposes of the IPR, Petitioner adopted the Patent Owner's proposed construction from related litigation: "waiting for a delay and then evaluating the proximate voltage to determine, after the delay, whether to enable a VAR compensation component based on the proximate voltage." This construction links the "monitoring" step directly to the claimed time delay function.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-3, 8-10, and 15-16 of Patent 9,293,922 as unpatentable.