DCT

3:21-cv-08534

CyboEnergy Inc v. Northern Electric Power Technology Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 3:21-cv-08534, N.D. Cal., 05/09/2022
  • Venue Allegations: Venue is alleged to be proper based on Defendant maintaining a regular and established place of business in the district and committing the alleged acts of infringement within the district.
  • Core Dispute: Plaintiff alleges that Defendant’s solar microinverters infringe patents related to scalable, daisy-chainable power inversion systems and a method for maximizing power production in low-light conditions.
  • Technical Context: The technology concerns solar microinverters, which convert DC power from individual solar panels into AC power for a power grid, representing a key component in distributed renewable energy systems.
  • Key Procedural History: This First Amended Complaint follows an original complaint. The allegations of indirect infringement are currently based on knowledge from the date of the lawsuit's filing, with Plaintiff expressly reserving the right to amend its pleading upon discovery of pre-filing knowledge. Subsequent to its issuance, U.S. Patent No. 8,786,133 underwent an ex parte reexamination, which confirmed the patentability of asserted claims 15-24.

Case Timeline

Date Event
2009-07-16 '133 Patent Priority Date
2013-03-07 '489 Patent Priority Date
2014-07-22 '133 Patent Issue Date
2016-05-03 '489 Patent Issue Date
2022-05-09 First Amended Complaint Filing Date

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

U.S. Patent No. 8,786,133 - "Smart and Scalable Power Inverters," issued July 22, 2014

The Invention Explained

  • Problem Addressed: The patent identifies shortcomings with traditional, large centralized solar power inverters, including that they represent a single point of failure for the entire system, are costly, and are inefficient because the system's performance is dictated by the weakest-performing solar module (’133 Patent, col. 1:35-48).
  • The Patented Solution: The invention describes a decentralized system using multiple "smart" microinverters, where each inverter connects to one or more DC power sources. These inverters are designed to connect to each other in a "daisy chain" on the AC side, which simplifies wiring and allows the system to be scaled up or down easily by adding or removing inverters and their associated power sources (’133 Patent, col. 1:17-28; Fig. 3). This architecture is intended to improve system resilience and maximize energy production from each individual module.
  • Technical Importance: This decentralized, scalable approach was designed to overcome the installation complexity and performance bottlenecks of centralized inverter systems, thereby improving overall efficiency and flexibility in solar installations (’133 Patent, col. 1:59-62).

Key Claims at a Glance

  • The complaint asserts independent claims 15 and 19.
  • Independent Claim 15 (System):
    • A plurality of power inverters, each including a single DC-AC inverter, at least two DC power input ports, an AC power input port, and an AC power output port.
    • Each of the DC power input ports has one DC power source connected to it.
    • The AC output port of each inverter is connected in a daisy chain to the AC input port of the next inverter, with the last inverter connecting to a power service panel.
    • The system is incrementally scalable by adding or subtracting DC power sources and daisy-chained inverters.
  • Independent Claim 19 (Method):
    • Providing a plurality of DC power sources and a plurality of DC to AC power inverters with the port configuration described in claim 15.
    • Connecting at least one DC power source to each DC input port.
    • Providing AC power to the power grid.
  • The complaint notes that it accuses infringement of one or more of claims 1-24, reserving the right to assert additional claims (Compl. ¶9).

U.S. Patent No. 9,331,489 - "Maximizing Power Production at Low Sunlight by Solar Power Mini-Inverters," issued May 3, 2016

The Invention Explained

  • Problem Addressed: Standard solar inverters often shut down in low-light conditions (e.g., sunrise, sunset, or partial shading) because the connected solar panel cannot produce sufficient power to simultaneously operate the inverter's internal electronics and generate AC power for the grid (’489 Patent, col. 3:1-14).
  • The Patented Solution: The patent describes a multi-channel inverter that can operate in a "low power mode." In this mode, the inverter detects the low-power condition and dedicates the power from one of its input channels exclusively to run its internal electronics. The remaining channels continue to generate AC power from their respective solar panels, allowing the inverter to remain operational and productive during periods of low irradiance when it would otherwise be offline (’489 Patent, col. 1:55-64; Fig. 3).
  • Technical Importance: This mode of operation allows the inverter to extend its power generation window each day, thereby "harvesting more sun power" and increasing the total energy output of the solar power system (’489 Patent, col. 9:55-60).

Key Claims at a Glance

  • The complaint asserts independent claim 14.
  • Independent Claim 14 (Apparatus):
    • An m-channel solar power inverter with at least two DC input channels.
    • An AC power output port to supply AC power to an electric grid.
    • A DC power combiner connected to the DC-DC boost converters of the input channels.
    • A digital microcontroller arranged to calculate DC input power for each channel and run the inverter in a "normal or low power mode" based on that calculation.
    • A DC power supply connected to all input channels via the combiner, which is "configured to take DC power from a dedicated input channel" when the microcontroller detects that the input power is below a pre-determined value.
  • The complaint notes that it accuses infringement of one or more of claims 1-16 (Compl. ¶16).

III. The Accused Instrumentality

Product Identification

  • The accused instrumentalities are Defendant's BDM-600 and BDM-800 series solar microinverters, identified as "Dual Module Microinverters" (Compl. ¶10, pp. 4, 6).

Functionality and Market Context

  • The complaint alleges these products are solar inverters that convert DC power from solar panels into AC power for a power grid (Compl. ¶10, p. 4). They are described as having multiple DC input ports to connect to individual solar panels and AC ports that allow multiple inverters to be connected together to form a "continuous AC branch circuit" (Compl. ¶10, p. 5). The complaint alleges that Defendant's product documentation, such as the "Installation and Operations Manual," instructs users on how to connect the inverters in this scalable, daisy-chained fashion (Compl. ¶10, p. 5). The inverters are also alleged to have features like Maximum Power Point Tracking (MPPT) to manage issues such as partial shading (Compl. ¶17, p. 11).

IV. Analysis of Infringement Allegations

’133 Patent Infringement Allegations

The complaint includes a system diagram from Defendant's documentation showing multiple microinverters connected to solar panels and daisy-chained together to supply power to the grid (Compl. ¶10, p. 4). A product diagram of the BDM-800 inverter is also provided, with labels identifying the "DC Input Port 1", "DC Input Port 2", "AC Input Port", and "AC Output Port" (Compl. ¶10, p. 5).

Claim Element (from Independent Claim 15) Alleged Infringing Functionality Complaint Citation Patent Citation
a) a plurality of power inverters, each of said power inverters including a single DC-AC inverter, at least two DC power input ports coupled to the single DC-AC inverter, an AC power input port, and an AC power output port... The accused BDM-600 and BDM-800 inverters are alleged to be sold as a system with a plurality of inverters, each with the claimed port configuration. ¶10 col. 5:45-51
b) said AC power output port of each power inverter being connected in a daisy chain to the AC power input port of the next power inverter, except for the AC power input port of the first power inverter being left open... Defendant's installation manual allegedly instructs users to "Plug the AC connectors of neighboring BDM inverters to form a continuous AC branch circuit." ¶10 col. 3:41-50
c) whereby said system is incrementally scalable by adding or subtracting DC power sources and daisy-chained inverters. Plaintiff alleges that the product datasheet's specification of a "Maximum Number of Units Per Branch" implies that the system is scalable by adding or subtracting inverters. ¶10 col. 1:17-28
  • Identified Points of Contention:
    • Scope Questions: A central question may be whether the term "daisy chain," as used in the patent, reads on the accused products' method of forming a "continuous AC branch circuit." The defense may argue that its connection topology (e.g., using T-connectors to a trunk cable) is distinct from the specific pass-through arrangement illustrated in the patent's figures.
    • Technical Questions: The complaint relies on Defendant's product manuals and datasheets. A factual question will be whether the actual physical and electrical operation of the accused systems conforms to the functions described in that literature and required by the claims.

’489 Patent Infringement Allegations

The complaint again presents a diagram of the accused BDM-800 microinverter, highlighting its multiple "DC Input Port" connections (Compl. ¶17, p. 10).

Claim Element (from Independent Claim 14) Alleged Infringing Functionality Complaint Citation Patent Citation
a) at least two DC input channels, each of which comprises a DC-DC boost converter, measurement circuits... to connect to a solar panel; The BDM-800 datasheet is cited to show the inverter has at least two DC input channels. The complaint infers that each channel must include a DC boost converter and associated circuits to receive power from a solar panel. ¶17 col. 4:27-31
d) a digital microcontroller... constructed to run the power inverter in normal or low power mode based on calculated DC input power; The complaint alleges that a microcontroller is a "necessary component" to perform MPPT, a feature the accused products have, and that it "will have to connect to the DC-DC boost converters" to perform this function. ¶17 col. 5:1-14
e) a DC power supply... configured to take DC power from a dedicated input channel... when the digital microcontroller detects that the calculated input power is below a pre-determined value. The complaint alleges that because the inverter's electronics require DC power, it "will have to include a DC power supply" and that this supply would be connected to the input channels. There is no direct allegation of this specific low-power mode function. ¶17 col. 5:29-41
  • Identified Points of Contention:
    • Technical Questions: The infringement allegations for the '489 patent appear to be largely inferential. The complaint alleges the presence of components like a microcontroller and a DC power supply but does not provide specific factual allegations or evidence that these components operate in the claimed "low power mode." A key question will be what evidence exists to show the accused inverters actually dedicate one input channel to power internal electronics during low-light conditions, as specifically required by the claim, rather than simply shutting down.

V. Key Claim Terms for Construction

  • The Term: "daisy chain" (’133 Patent, Claim 15)

    • Context and Importance: This term is fundamental to the '133 patent's claimed invention of a scalable, easily-wired system. The definition of how the inverters must be connected will be critical to the infringement analysis.
    • Intrinsic Evidence for a Broader Interpretation: The patent specification states that "the generated AC power from each power inverter is added in parallel onto the AC powerline," which may support a broader construction covering any connection scheme that achieves parallel power addition, not just a literal serial connection (’133 Patent, col. 4:63-65).
    • Intrinsic Evidence for a Narrower Interpretation: The claim language recites connecting "the AC power output port of each power inverter... to the AC power input port of the next power inverter." This, combined with figures like Fig. 3 showing distinct input (51) and output (52) ports, could support a narrower construction limited to a specific pass-through architecture.

  • The Term: "configured to take DC power from a dedicated input channel" (’489 Patent, Claim 14)

    • Context and Importance: This phrase defines the core mechanism of the "low power mode" invention. Infringement hinges entirely on whether the accused product performs this specific function.
    • Intrinsic Evidence for a Broader Interpretation: A plaintiff may argue the term should be interpreted functionally to cover any operational mode where one input is prioritized to provide internal power to prevent a shutdown, even if the dedication is not permanent or exclusive.
    • Intrinsic Evidence for a Narrower Interpretation: The term "dedicated" suggests a formal, exclusive assignment of function. The specification explains that the microcontroller controls a DC-DC converter to "stop[] pulling power from its connected solar panel for AC power generation," so that power can instead be routed to the DC power supply (’489 Patent, col. 5:30-38). This language may support a narrower construction requiring a clear and distinct separation of functions between the dedicated channel and the power-generating channels.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges both induced and contributory infringement. The inducement claim is based on allegations that Defendant's installation and operations manuals instruct customers on how to assemble and use the accused products in an infringing manner (Compl. ¶11, ¶18). The contributory infringement claim is based on the same acts, coupled with an allegation of knowledge (Compl. ¶12, ¶19).
  • Willful Infringement: The complaint does not use the term "willful." However, it alleges that Defendant has known of the patents-in-suit and the underlying technology "from at least the date of the lawsuit filing" (Compl. ¶11, ¶12, ¶18, ¶19). These allegations establish a basis for a claim of post-filing willful infringement. The complaint also expressly reserves the right to amend its pleadings if pre-filing knowledge is uncovered in discovery (Compl. p. 9 n.1, p. 13 n.3).

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

  • A key evidentiary question will be one of operational functionality: Does Plaintiff possess evidence that the accused NEP inverters perform the specific "low power mode" claimed in the '489 patent—namely, dedicating one solar panel input to power internal electronics while other inputs continue generating grid power—or are the allegations based on inference without direct proof of this function?
  • A central issue for the '133 patent will be one of definitional scope: Can the term "daisy chain", as defined in the context of a pass-through architecture with distinct AC input and output ports, be construed to cover the accused products' method of forming a "continuous AC branch circuit"?
  • A third question will relate to knowledge and damages: As the complaint currently pleads knowledge only from the date of filing, a critical issue for indirect infringement and potential enhanced damages will be whether Plaintiff can produce evidence during discovery demonstrating that Defendant had knowledge of the patents prior to the lawsuit's commencement.