DCT

1:21-cv-11446

General Electric Co v. Gamesa Electric Sau

Log In

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:21-cv-11446, D. Mass., 02/22/2023
  • Venue Allegations: Venue is based on Defendant Siemens Gamesa Renewable Energy Inc. having a regular and established place of business and committing alleged acts of infringement in the District of Massachusetts, with venue over the foreign defendants premised on an alter ego theory.
  • Core Dispute: Plaintiff alleges that Defendant’s onshore and offshore wind turbines infringe patents related to maintaining connection to the power grid during low-voltage and zero-voltage events.
  • Technical Context: The technology addresses the critical need for wind turbines to remain operational and synchronized with the power grid during electrical faults, a capability essential for grid stability as renewable sources constitute a larger share of energy production.
  • Key Procedural History: The asserted patents have a significant litigation and post-grant review history. The ’985 Patent survived an inter partes reexamination and two IPR challenges from competitors. The ’705 Patent similarly survived multiple reexaminations and an IPR that was dismissed following a license agreement. Most notably, the parties previously litigated these patents at the International Trade Commission (ITC), where the defendants were found to infringe claims of both patents. However, the ITC's Administrative Law Judge also found claim 1 of the '705 Patent ineligible under 35 U.S.C. § 101, a non-binding conclusion that the plaintiff disputes in the current action.

Case Timeline

Date Event
2003-01-24 U.S. Patent No. 6,921,985 Priority Date
2005-07-26 U.S. Patent No. 6,921,985 Issued
2006-10-20 U.S. Patent No. 7,629,705 Priority Date
2009-12-08 U.S. Patent No. 7,629,705 Issued
2012-03-08 Jury finds '705 Patent infringed in prior litigation
2012-10-22 Inter partes reexamination of '985 Patent filed
2013-07-12 Ex parte reexamination certificate confirms '705 Patent claim 1
2014-04-24 Second ex parte reexamination certificate confirms '705 Patent claim 1
2016-08-17 Inter partes reexamination certificate issues for '705 Patent
2019-07-01 PTAB terminates IPR on '985 Patent after settlement
2020-07-31 GE files ITC complaint, providing alleged notice of infringement
2020-09-08 ITC institutes investigation involving the Asserted Patents
2021-09-02 GE files original complaint in D. Mass.
2023-02-22 Amended Complaint Filed

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 6,921,985 - "Low Voltage Ride Through for Wind Turbine Generators," Issued July 26, 2005

The Invention Explained

  • Problem Addressed: As wind farms became larger contributors to electrical grids, grid operators began requiring turbines to remain connected during grid voltage sags, rather than "tripping offline" as they had previously done ('985 Patent, col. 1:12-33; Compl. ¶20). A key challenge is that during a low voltage event, a turbine may lack sufficient power for its own control systems, and without the electrical load from the grid, its rotor can accelerate to dangerous overspeed levels ('985 Patent, col. 4:19-27).
  • The Patented Solution: The invention describes a system that uses an uninterruptible power supply (UPS) to provide backup power to critical components, specifically the turbine controller and the blade pitch control system, during a low voltage event ('985 Patent, Abstract; col. 4:28-40). This allows the controller to actively adjust the pitch of the turbine blades to manage rotor speed and keep the generator synchronized with the grid, enabling it to "ride through" the fault (Compl. ¶24). The system may also temporarily shut down non-vital subsystems to conserve power ('985 Patent, col. 2:30-34).
  • Technical Importance: This "low-voltage ride through" (LVRT) capability was a critical step in integrating large-scale wind power into modern, stable electrical grids (Compl. ¶20).

Key Claims at a Glance

  • The complaint asserts independent claims 1 and 29, and dependent claims 6, 12, and 15 (Compl. ¶57). Amended independent claim 1, as modified by reexamination, is central to the infringement allegations and includes the following essential elements:
    • A wind turbine generator comprising a generator, a blade pitch control system, and a turbine controller.
    • A first power source (e.g., the grid) to provide power during a first, normal mode of operation.
    • An uninterruptible power supply (UPS) coupled to the controller and pitch system to provide power during a low voltage event where the generator remains connected to the grid and the voltage is less than 50% of rated voltage.
    • Wherein, upon detecting a transition to a second mode of operation that comprises the low voltage event, the turbine controller causes the blade pitch control system to vary the blade pitch in response.

U.S. Patent No. 7,629,705 - "Method and Apparatus for Operating Electrical Machines," Issued December 8, 2009

The Invention Explained

  • Problem Addressed: The '705 Patent addresses a more severe fault than LVRT: a "zero-voltage event," where the grid voltage drops to nearly zero. In this condition, a turbine's control system is effectively "blind" to the grid's phase and frequency, making it difficult to maintain synchronization for a quick recovery ('705 Patent, col. 6:62-67; Compl. ¶31).
  • The Patented Solution: The invention discloses a method and a control system, featuring a phase-locked loop (PLL) regulator, that enables an electrical machine to remain connected to the power system during and after a zero-voltage event ('705 Patent, Abstract). The control system is configured to prevent its internal frequency reference from "wandering" during the outage, such that when grid voltage returns, the turbine is already synchronized and can immediately resume power delivery, thereby supporting grid recovery ('705 Patent, col. 10:26-42; Compl. ¶34).
  • Technical Importance: This "zero-voltage ride through" (ZVRT) capability represents an advancement over LVRT, providing greater grid stability by mitigating the risk of cascading failures during the most severe types of electrical grid disturbances (Compl. ¶32).

Key Claims at a Glance

  • The complaint asserts independent claim 1 and dependent claims 2 and 3 (Compl. ¶72). Independent claim 1 recites:
    • A method for operating an electrical machine coupled to an electric power system.
    • The method comprises configuring the machine to remain electrically connected to the power system during and after a voltage amplitude operates outside a predetermined range.
    • This configuring step involves electrically coupling a control system to the power system and placing it in electronic data communication with the electrical machine.
    • The configuration is such that the machine remains connected even when the voltage decreases to "approximately zero volts for the undetermined period of time, thereby facilitating zero voltage ride through (ZVRT)."

III. The Accused Instrumentality

Product Identification

The accused instrumentalities are a wide range of Siemens Gamesa's onshore and offshore variable speed wind turbine generators, including but not limited to the SWT 2.3-108, SG 5.0-145, SG 8.0-167 DD, and SG 14-222 DD models (Compl. ¶52).

Functionality and Market Context

The complaint alleges these turbines are sold and used in the U.S. with LVRT and ZVRT capabilities (Compl. ¶52). The complaint specifically alleges that component parts—including controllers, converters, and software—are designed and "always configured to perform LVRT and/or ZVRT in a manner that infringes" the asserted patents (Compl. ¶53). The SG 4.5 model is used as a representative example to explain the allegedly infringing functionality for both patents (Compl. ¶¶61, 73-77). The complaint's visual evidence shows a marketing brochure for the "New SG 4.5-145 wind turbine," which is described as a "new generation of turbines" featuring a "doubly-fed induction generator" (Compl. p. 20).

IV. Analysis of Infringement Allegations

'985 Patent Infringement Allegations

Claim Element (from Independent Claim 1, as amended) Alleged Infringing Functionality Complaint Citation Patent Citation
A wind turbine generator comprising: a generator; a blade pitch control system to vary a pitch of one or more blades; a turbine controller coupled with the blade pitch control system; The Accused Products are wind turbine generators that include a generator, a blade pitch control system, and a turbine controller. The SG 4.5 turbine is identified as a representative example (Compl. p. 20). ¶¶59-60 col. 4:44-50
a first power source coupled with the turbine controller and with the blade pitch control system to provide power during a first mode of operation; During normal operation (a "first mode"), the grid/generator is the source of power for the controller and pitch system. This mode corresponds to a control system signal, "CcuDipOn," being set to FALSE. ¶61 col. 5:32-37
an uninterruptible power supply coupled to the turbine controller and with the blade pitch control system to provide power during a low voltage event in which the generator ... is less than 50% of a rated voltage... The Accused Products include a UPS that powers the turbine controller and blade pitch control system during a low voltage event where the voltage is less than 50% of the rated voltage. ¶¶62-63 col. 5:37-43
wherein in response to detection of a transition from the first mode of operation to a second mode of operation comprising the low voltage event the turbine controller causes the blade pitch control system to vary the pitch... A transition to a "second mode of operation" (when CcuDipOn is set to TRUE), which comprises the low voltage event, is detected. In response, the turbine controller generates an "optimized pitch reference" to vary the pitch of the blades. ¶64 col. 5:26-31

Identified Points of Contention

  • Scope Questions: A central question may be whether the accused products' "second mode of operation," allegedly triggered by the "CcuDipOn" signal, corresponds to the specific mode recited in the claim. The defense may argue its operational modes are distinct from the claimed "second mode of operation comprising the low voltage event."
  • Technical Questions: What evidence demonstrates that the generation of an "optimized pitch reference" is caused in response to the detection of the transition to the second mode, as the claim requires? The analysis will likely focus on the logic and timing of the accused control software to determine if the alleged cause-and-effect relationship meets the claim language.

'705 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A method for operating an electrical machine, said method comprising: coupling the electrical machine to an electric power system... The operation of the Accused Products involves coupling the generator (an electrical machine) to the electrical grid. ¶73 col. 1:47-52
configuring the electrical machine such that the electrical machine remains electrically connected to the electric power system during and subsequent to a voltage amplitude...operating outside of a predetermined range... The Accused Products are configured to remain electrically connected to the grid when grid voltage drops to approximately zero for a period of up to 500 milliseconds. ¶74 col. 6:58-67
said configuring... comprising: electrically coupling at least a portion of a control system to at least a portion of the electric power system; The Accused Products include a converter control unit (CCU), which is a control system that is electrically coupled to the electric power system. ¶75 col. 7:56-61
coupling the control system in electronic data communication with at least a portion of the electrical machine; and The CCU is in electronic data communication with the generator to obtain rotor speed measurements. ¶76 col. 11:1-6
configuring the electrical machine and the control system such that the electrical machine remains electrically connected...during...the voltage amplitude...decreasing below the predetermined range including approximately zero volts... The control unit and generator are configured to ensure the generator remains connected during a voltage drop to approximately zero volts, thereby facilitating ZVRT. ¶77 col. 11:39-47

Identified Points of Contention

  • Scope Questions: What is the proper construction of "approximately zero volts"? This term is not explicitly defined with a numerical value in the patent and will be a critical point of dispute, distinguishing the claimed ZVRT from conventional LVRT. The interpretation of "undetermined period of time" will also be central to defining the claim's scope.
  • Technical Questions: The complaint alleges on "information and belief" that the accused products practice the dependent claims by using a PLL and associated algorithms to satisfy industry standards like IEEE 1547-2018 (Compl. ¶¶78-82). A key question will be whether compliance with an industry standard is sufficient to prove that the products perform the specific steps of the patented method, or if there is a technical mismatch between the standard's requirements and the claim limitations.

V. Key Claim Terms for Construction

'985 Patent

  • The Term: "in response to detection of a transition from the first mode of operation to a second mode of operation"
  • Context and Importance: This phrase establishes the causal link and timing for the claimed protective action (varying the blade pitch). The infringement case depends on mapping the accused product's change in operational state (e.g., the "CcuDipOn" signal changing) to this claimed "transition." Practitioners may focus on this term because the defense could argue that their pitch control adjustments are triggered directly by voltage levels or rotor speed, not by a discrete "detection of a transition" between defined modes.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification discusses detecting a "low voltage event" generally, which could support an interpretation where any system logic that recognizes the fault condition and acts upon it constitutes the claimed "detection of a transition" ('985 Patent, col. 6:11-12).
    • Evidence for a Narrower Interpretation: The flow chart in Figure 6 shows "DETECT LOW VOLTAGE EVENT" as a distinct, initial step (600), followed by other actions ('985 Patent, Fig. 6). This could support a narrower reading that requires a specific, discrete detection event that initiates a new mode, rather than a continuous response to changing conditions.

'705 Patent

  • The Term: "approximately zero volts"
  • Context and Importance: The definition of this term is fundamental to the patent's novelty and the infringement analysis, as it distinguishes the claimed "ZVRT" from prior art "LVRT." The court's construction will determine the threshold for a grid fault severe enough to fall within the patent's scope. Practitioners may focus on this term because its ambiguity creates a significant risk for both parties.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The patent contrasts ZVRT with LVRT, where "the voltage amplitude rapidly decreases, yet does not decrease to zero volts" ('705 Patent, col. 6:65-67). This suggests "approximately zero" means a condition qualitatively different and more severe than a standard low-voltage sag, without requiring a literal zero reading.
    • Evidence for a Narrower Interpretation: The abstract states the invention facilitates connection "subsequent to a voltage amplitude of the electric power system operating outside of a predetermined range." The description of the graph in Figure 3 refers to a "zero voltage transient" and a "zero voltage condition" starting at time zero, which could imply a very narrow range close to absolute zero ('705 Patent, col. 6:20-27).

VI. Other Allegations

  • Indirect Infringement: The complaint alleges induced infringement for both patents based on Siemens Gamesa providing customers with instruction manuals, field technicians, and commissioning support that allegedly instruct on the use of the infringing LVRT and ZVRT features (Compl. ¶¶54, 66, 89). Contributory infringement is alleged on the basis that the defendants supply components (e.g., controllers, converters) that are a material part of the patented inventions and are not staple articles of commerce suitable for substantial non-infringing use (Compl. ¶¶67, 90).
  • Willful Infringement: Willfulness is alleged for both patents. The complaint bases this on defendants' alleged knowledge of the patents stemming from prior correspondence, the filing of the ITC complaint on July 31, 2020, and the fact that the defendants' alleged infringement continued after this notice (Compl. ¶¶69, 92).

VII. Analyst’s Conclusion: Key Questions for the Case

  • A core issue will be one of definitional scope: can the term "approximately zero volts" in the '705 Patent be construed to cover the specific fault conditions (e.g., voltage drops for up to 500ms) that the accused turbines are designed to ride through, or will it be limited to a stricter, near-zero condition that the accused products may not encounter or address in the claimed manner?
  • A key evidentiary question will be one of functional mapping: for the '985 Patent, does the accused turbine's control logic, specifically the "CcuDipOn" signal and subsequent "optimized pitch reference," perform the precise sequence of "detection of a transition" that "causes" the pitch to vary, as required by claim 1? This will require a detailed technical comparison of the accused software's operation against the claim's specific causal language.
  • A central procedural question will be the persuasive weight of prior proceedings: how will the extensive history, particularly the ITC's finding of infringement but also the § 101 ineligibility ruling for the '705 Patent's lead claim, influence the court’s own analysis? While not legally binding, the detailed technical record and legal arguments from the ITC investigation will likely shape the strategies and evidence presented in this case.