General Electric Co v. Vestas Wind Systems A S

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: General Electric Co. (New York)
  • Defendant: Vestas Wind Systems A/S (Denmark); Vestas-American Wind Technology, Inc. (California)
  • Plaintiff’s Counsel: Raines Feldman LLP; Weil, Gotshal & Manges LLP
• Case Identification: 2:17-cv-05653, C.D. Cal., 07/31/2017
• Venue Allegations: Venue is alleged to be proper as Defendant Vestas-American Wind Technology, Inc. is incorporated in California, and thus resides in the district. Defendant Vestas Wind Systems A/S is a foreign entity that may be sued in any judicial district.
• Core Dispute: Plaintiff alleges that Defendant’s variable speed wind turbines infringe a patent related to technology that allows a turbine to remain connected to the power grid during severe voltage drops, a feature known as Zero Voltage Ride Through (ZVRT).
• Technical Context: The technology addresses the need for power grid stability by preventing large wind turbines from disconnecting during transient voltage faults, which was a significant operational problem for renewable energy integration.
• Key Procedural History: The complaint highlights that the patent-in-suit was previously litigated against Mitsubishi, resulting in a finding of infringement, a damages award exceeding $170 million, and a permanent injunction, which was followed by a settlement. The complaint also notes that the patentability of the asserted claim was confirmed through multiple ex parte and inter partes reexamination proceedings at the U.S. Patent and Trademark Office.

Case Timeline

Date	Event
2006-10-20	’705 Patent Priority Date
2009-12-08	’705 Patent Issue Date
2010-02-11	GE files suit against Mitsubishi on ’705 Patent
2011-03-24	Mitsubishi requests inter partes reexamination of ’705 Patent
2011-09-14	Alleged date of Defendants' knowledge of ’705 Patent via subpoena
2012-09-14	Mitsubishi requests first ex parte reexamination of ’705 Patent
2013-03-24	Mitsubishi requests second ex parte reexamination of ’705 Patent
2013-07-12	First ex parte reexamination certificate confirms patentability of Claim 1
2013-12-XX	GE and Mitsubishi reach settlement
2014-04-24	Second ex parte reexamination certificate confirms patentability of Claim 1
2016-08-17	Inter partes reexamination certificate confirms patentability of Claims 7-8
2017-07-31	Complaint Filing Date

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

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

• Patent Identification: U.S. Patent No. 7,629,705, "Method and Apparatus for Operating Electrical Machines," issued December 8, 2009.

The Invention Explained

• Problem Addressed: The patent addresses the problem of grid-connected wind turbines disconnecting from the power grid during voltage fluctuations, such as short circuits or lightning strikes. This disconnection, while intended to protect the turbine, can destabilize the overall power grid, especially as wind power constitutes a larger portion of energy generation (’705 Patent, col. 1:28-40).
• The Patented Solution: The invention is a method and control system for an electrical machine (e.g., a wind turbine generator) that allows it to remain electrically connected to the power grid during and after severe voltage drops, including events where the voltage drops to "approximately zero volts" for a period of time (’705 Patent, Abstract). The control system, which may use a phase-locked loop (PLL) regulator, dynamically adjusts its operating parameters to manage the fault without tripping offline, thereby supporting grid stability instead of contributing to its disruption (’705 Patent, col. 8:28-47; Fig. 4).
• Technical Importance: This "ride-through" capability, particularly for zero-voltage events (ZVRT), allows wind farms to behave more like conventional power plants, enhancing grid reliability and enabling higher penetration of renewable energy sources (’705 Patent, col. 8:43-47).

Key Claims at a Glance

• The complaint asserts infringement of at least independent Claim 1 (Compl. ¶18).
• The essential elements of independent Claim 1 are:
  • A method for operating an electrical machine, comprising:
  • coupling the electrical machine to an electric power system configured to transmit power;
  • configuring the machine to remain connected to the power system during and after a voltage amplitude operates outside a predetermined range for an undetermined period of time;
  • wherein said configuring comprises:
    • electrically coupling a control system to the power system;
    • coupling the control system in electronic data communication with the electrical machine; and
    • configuring the machine and control system to remain connected during and after the voltage decreases below the predetermined range, including to "approximately zero volts for the undetermined period of time," thereby facilitating zero-voltage ride-through (ZVRT).
• The complaint does not explicitly reserve the right to assert dependent claims, but the broad language of the infringement count ("one or more claims") leaves this possibility open (Compl. ¶9).

III. The Accused Instrumentality

Product Identification

• The Accused Products include, but are not limited to, Defendants' V90-3.0, V100-2.0, V112-3.0, and V117-3.3 wind turbines (Compl. ¶18).

Functionality and Market Context

• The complaint alleges that the Accused Products are variable speed wind turbines equipped with "ride-through capabilities" designed to keep the turbines connected to the grid during electrical faults (Compl. ¶23). This functionality is allegedly managed by a "Vestas Multi Processor (VMP) Controller," which monitors the grid and controls the turbine's operation during voltage disturbances (Compl. ¶¶ 24, 25).
• The complaint provides visual evidence from a Vestas brochure for its V117 turbine, which includes a "Low voltage tolerance curve." This chart graphically depicts the turbine's designed capability to stay connected to the grid when voltage drops to zero for a short duration. (Compl. ¶23, p. 9).
• The complaint alleges that these features are marketed as providing "advanced grid compliance" and support for "grid levels and stability in the event of grid disturbances" (Compl. ¶23). This functionality is central to meeting modern grid code requirements for renewable energy installations.

IV. Analysis of Infringement Allegations

• Claim Chart Summary:

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 such that the electric power system is configured to transmit at least one phase of electric power to the electrical machine;	The Accused Products are wind turbines with either a doubly-fed induction generator (DFIG) or a full conversion generator, which is coupled to a three-phase electric power system. A diagram from a Vestas brochure illustrates the generator connected to the grid interface through various components. (Compl. ¶22, p. 7).	¶22	col. 2:48-54
and configuring the electrical machine such that the electrical machine remains electrically connected to the electric power system during and subsequent to a voltage amplitude of the electric power system operating outside of a predetermined range for an undetermined period of time...	The Accused Products are configured with "ride-through capabilities" to remain connected during voltage events. This is supported by a Vestas brochure stating its products are "designed so that your wind park will be fully compliant with applicable grid codes" and a graph showing a "Low voltage tolerance curve." (Compl. ¶23, p. 9).	¶23	col. 2:41-47
...said configuring the electrical machine comprising: electrically coupling at least a portion of a control system to at least a portion of the electric power system;	The Accused Products are controlled by a "Vestas Multi Processor (VMP) Controller," which monitors the electric power system and operates the turbine during voltage disturbances. An excerpt from a Vestas presentation shows this controller synchronizing the generator to the grid. (Compl. ¶24, p. 10).	¶24	col. 2:55-60
coupling the control system in electronic data communication with at least a portion of the electrical machine; and	The VMP Controller allegedly includes a processor for the turbine's power converter and is in electronic data communication with it to provide "monitoring and supervision of overall operation" and "operating the wind turbine during various fault situations." An excerpt from a Vestas specification details the VMP Controller's functions. (Compl. ¶25, p. 11).	¶25	col. 7:1-3
configuring the electrical machine and the control system such that the electrical machine remains electrically connected to the electric power system during and subsequent to the voltage amplitude of the electric power system decreasing below the predetermined range including approximately zero volts for the undetermined period of time, thereby facilitating zero-voltage ride-through (ZVRT).	The Accused Products are configured with ride-through capabilities to remain connected when voltage drops to "approximately zero volts," facilitating ZVRT. This is evidenced by a Vestas brochure stating the turbine has "Zero Voltage Ride Through: 0.5 s" and a fault-tolerance graph showing operation at 0 volts for approximately 0.45 seconds. (Compl. ¶26, p. 9, 13-14).	¶26	col. 8:28-47

• Identified Points of Contention:
  • Scope Questions: A central dispute may arise over the construction of "undetermined period of time." The defense could argue that the accused systems, which are designed to ride through faults for a specified duration (e.g., "0.5 s" as cited in the complaint at ¶26), do not operate for an "undetermined" period as required by the claim.
  • Technical Questions: The analysis may focus on whether the accused VMP Controller functions in a way that meets the limitations of the "control system" as described in the patent. The patent discloses a specific control system using a multi-state phase-locked loop (PLL) regulator (’705 Patent, Figs. 4-5), raising the question of whether the accused controller must possess similar features or if a more generic controller suffices.
  • Scope Questions: The term "approximately zero volts" will likely be a point of contention. The question will be what technical threshold this term implies and whether the accused products' low-voltage ride-through performance, as depicted in their own technical documents, falls within that scope.

V. Key Claim Terms for Construction

• The Term: "undetermined period of time"

• Context and Importance: This term is critical because the Accused Products are allegedly designed to ride through faults for a specific, or "determined," duration (e.g., 0.5 seconds). The infringement analysis will depend on whether this claim language can read on a system with a pre-set, albeit not instantaneous, fault tolerance window.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The patent's abstract and claims use the term without quantitative limits, suggesting it should be given its plain and ordinary meaning of a non-specific duration, contrasting with systems that would disconnect instantly (’705 Patent, Abstract; col. 11:51-53).
  • Evidence for a Narrower Interpretation: The specification includes an exemplary embodiment where a zero-voltage condition lasts for a specific duration of "0.15 seconds" (’705 Patent, Fig. 3; col. 5:30-35). A defendant may argue this example limits the scope of "undetermined" to short, transient events of a similar magnitude.

• The Term: "approximately zero volts"

• Context and Importance: The scope of this term defines the severity of the grid fault the patented method addresses. Infringement will depend on whether the low-voltage events the Accused Products are designed to handle qualify as "approximately zero."

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The patent repeatedly distinguishes its invention, "zero voltage ride through (ZVRT)," from the prior art concept of "low voltage ride through (LVRT)," suggesting "approximately zero" is meant to encompass the most severe category of voltage sags, including a complete loss of voltage on the grid bus (’705 Patent, col. 5:65-col. 6:2).
  • Evidence for a Narrower Interpretation: The use of "approximately" indicates the value is not strictly absolute zero. A defendant may point to embodiments or technical constraints to argue that the term requires the voltage to fall below a specific, very low (but non-zero) threshold, and that their system operates differently.

VI. Other Allegations

• Indirect Infringement: The complaint alleges contributory infringement, asserting that Defendant Vestas A/S knows the Accused Products "are especially made or especially adapted for use in the infringement" of Claim 1, are a "material part of the invention," and have "no substantial non-infringing use" (Compl. ¶30). The allegation is that the ZVRT components and control systems are specifically designed to practice the patented method.
• Willful Infringement: Willfulness is alleged based on Defendants having actual knowledge of the ’705 patent since at least September 14, 2011 (Compl. ¶31). This knowledge is alleged to stem from subpoenas served on Vestas-American and one of its engineers in connection with prior litigation between GE and Mitsubishi involving the same patent. The complaint states the subpoena specifically requested information on "methods and apparatuses of Vestas for... operat[ing]... during low voltage or zero voltage events" (Compl. ¶29).

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

• A core issue will be one of definitional scope: Can the claim terms "undetermined period of time" and "approximately zero volts" be construed to read on the accused turbines, which are marketed with specific, quantified ride-through capabilities (e.g., "0.5 s" at zero volts)? The outcome of claim construction on these terms appears central to the infringement analysis.
• A key evidentiary and legal question will surround willfulness. Given the patent's robust post-grant history and the specific allegation that Defendants were on notice via a subpoena in the prior Mitsubishi litigation, the case will likely involve a detailed examination of whether Defendants' continued alleged infringement after September 2011 constituted objective recklessness.
• A final question will be one of technical implementation: Does the accused "VMP Controller" function in a way that infringes the "configuring" steps of Claim 1, particularly in light of the patent's detailed disclosure of a specific phase-locked loop (PLL) control system embodiment? The dispute may focus on whether the claim requires such a specific implementation or covers any control system that achieves the ZVRT result.