DCT
2:23-cv-00311
CyboEnergy Inc v. Hoymiles Power Electronics USA Inc
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: CyboEnergy, Inc. (Delaware)
- Defendant: Hoymiles Power Electronics USA, Inc. (Delaware)
- Plaintiff’s Counsel: Ramey LLP
- Case Identification: 2:23-cv-00311, E.D. Tex., 06/27/2023
- Venue Allegations: Plaintiff alleges venue is proper because Defendant maintains a regular and established place of business in the district and has committed acts of infringement there.
- Core Dispute: Plaintiff alleges that Defendant’s power inverters infringe two patents related to scalable, multi-input solar power inverter systems and their method of operation in low-light conditions.
- Technical Context: The technology concerns solar power inverters, which are essential components that convert direct current (DC) from solar panels into alternating current (AC) suitable for use in the power grid.
- Key Procedural History: U.S. Patent No. 8,786,133 was the subject of an ex parte reexamination proceeding. The resulting certificate confirmed the patentability of claims 15-24, while claims 1-14 (which includes asserted independent claim 1) were not reexamined.
Case Timeline
| Date | Event |
|---|---|
| 2009-07-16 | U.S. Patent 8,786,133 Priority Date |
| 2013-03-07 | U.S. Patent 9,331,489 Application Filing Date |
| 2014-07-22 | U.S. Patent 8,786,133 Issue Date |
| 2016-05-03 | U.S. Patent 9,331,489 Issue Date |
| 2023-06-27 | Complaint Filing Date |
| 2025-02-13 | U.S. Patent 8,786,133 Reexamination Certificate Issue 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’s background section describes the shortcomings of traditional solar power systems that use a single, large, centralized inverter. These systems are identified as having a single point of failure, being costly and complex to wire, and suffering from system-wide performance degradation if even one solar panel is underperforming (e.g., due to shading) (’133 Patent, col. 1:36-57).
- The Patented Solution: The invention proposes a decentralized system using multiple, smaller "smart" inverters, each connected to one or more DC power sources. The key architectural feature is that the AC outputs of these inverters are connected in a "daisy chain," where the AC output port of one inverter connects to the AC input port of the next. This arrangement is described as a "pass-through" connection that adds the generated AC power from each inverter in parallel onto the power line, simplifying installation and improving scalability ('133 Patent, col. 3:52-64; Fig. 3).
- Technical Importance: This decentralized "daisy-chain" architecture was designed to increase the reliability, installation flexibility, and overall energy-harvesting efficiency of photovoltaic solar power systems ('133 Patent, col. 1:58-64).
Key Claims at a Glance
- The complaint asserts claims 1-24 (Compl. ¶8). Independent claim 1 is representative of the system claims.
- Independent Claim 1 recites a system for providing AC power, comprising:
- A plurality of power inverters, each having one DC power input port, an AC power input port, and an AC power output port.
- The AC power output port of each inverter being connected in a "daisy chain" to the AC power input port of the next inverter.
- Each power inverter including specific internal components, such as a DC-DC boost converter, a DC-AC inverter, an internal AC powerline, a load interface circuit, and an "MFA microcontroller" to manage the inverter’s functions.
- The complaint reserves the right to assert dependent claims (Compl. ¶8).
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: The patent identifies a specific operational challenge with solar inverters: in low-light conditions (such as sunrise, sunset, or cloud cover), a solar panel may not produce enough DC power to both operate the inverter's internal electronics and simultaneously generate AC power for the grid. This can force the inverter to repeatedly shut down and attempt to restart, leading to significant loss of potential power generation (’489 Patent, col. 4:1-19).
- The Patented Solution: The invention is a multi-channel power inverter that can operate in a "low power mode." In this mode, the inverter's microcontroller is programmed to dedicate one of its input channels exclusively to powering its own internal electronic circuits. This allows the remaining input channels to continue converting whatever DC power they receive into usable AC power, thereby enabling the inverter to operate and produce power in much lower light conditions than would otherwise be possible ('489 Patent, col. 5:26-44; col. 11:47-54).
- Technical Importance: This method allows a solar power system to extend its daily operational window, harvesting power during low-irradiance periods that are typically non-productive for conventional inverters ('489 Patent, col. 1:52-65).
Key Claims at a Glance
- The complaint asserts claims 1-16 (Compl. ¶15). Independent claim 1 is representative of the system claims.
- Independent Claim 1 recites a multiple channel DC-to-AC power inverter, comprising:
- At least two DC power input ports.
- An AC power output port to supply power to a grid.
- A digital microcontroller arranged to run the inverter in a "normal or low power mode based on calculated DC input power."
- A DC power supply configured to be powered by a "dedicated" input channel when the microcontroller detects that the input power is below a pre-determined value.
- The complaint reserves the right to assert dependent claims (Compl. ¶15).
III. The Accused Instrumentality
- Product Identification: The complaint accuses "power inverters" that are manufactured, offered for sale, and sold by Defendant Hoymiles (Compl. ¶8, ¶15). The complaint does not identify specific product models or series.
- Functionality and Market Context: The complaint alleges that the accused products are power inverters that perform infringing methods or processes (Compl. ¶2). It does not provide specific details about the technical operation or market position of the accused Hoymiles inverters. No probative visual evidence provided in complaint.
IV. Analysis of Infringement Allegations
The complaint refers to claim chart exhibits (Exhibits B and D) that were not included with the filing (Compl. ¶9, ¶16). The following analysis is based on the narrative infringement theory inferred from the patents and the complaint's general allegations.
'133 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a) a plurality of power inverters, each of said power inverters having one DC power input port, an AC power input port, and an AC power output port... | The complaint alleges Defendant sells power inverters that are used in systems containing a plurality of such devices, each with the claimed ports. | ¶8 | col. 11:40-42 |
| b) said AC power output port of each inverter being connected in a daisy chain to the AC power input port of the next inverter... | The complaint alleges the accused inverters are installed in a "daisy chain" configuration, as allegedly instructed by Defendant. | ¶10 | col. 11:43-46 |
| c) each of said power inverters including... i) a DC-DC boost converter... ii) a DC-AC inverter... v) an MFA microcontroller... | The complaint alleges that each accused inverter contains the internal components recited in the claim, including a microcontroller that performs control functions. | ¶8 | col. 11:51-65; col. 12:1-15 |
- Identified Points of Contention:
- Technical Question: A factual question for the court will be whether Hoymiles' inverters are, in practice, installed in the specific "daisy chain" configuration claimed, where the AC output port of one unit connects directly to the AC input port of the next.
- Scope Questions: The infringement analysis may focus on the definition of "daisy chain." A key question is whether the accused systems' method of AC connection meets the specific structural requirements of the claim, or if Plaintiff will argue for a broader functional interpretation.
'489 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| h) a digital microcontroller... arranged to perform... running the multiple channel DC-to-AC power inverter in normal or low power mode based on calculated DC input power | The complaint alleges the accused multi-channel inverters contain a microcontroller that operates the device in different modes depending on the level of input power. | ¶15 | col. 11:18-32 |
| l) a DC power supply... configured with one input channel and its connected solar panel dedicated to supply DC power to the DC power supply when the digital microcontroller detects that calculated input power is below a pre-determined value | The complaint alleges that in low-light conditions, the accused inverters use one of their input channels to power their internal electronics, while the other channels continue to generate power. | ¶15 | col. 11:47-54 |
- Identified Points of Contention:
- Technical Question: What evidence demonstrates that the accused inverters' "low power mode" functions as claimed? Specifically, discovery may focus on whether a single, specific input channel is "dedicated" to powering internal electronics, as opposed to the electronics drawing power from a combined input bus or another internal source.
- Evidentiary Question: The complaint does not specify how the accused products' logic determines that input power is "below a pre-determined value." A factual dispute may arise over whether the accused devices employ the specific triggering conditions for the low power mode as envisioned by the patent.
V. Key Claim Terms for Construction
'133 Patent
- The Term: "daisy chain"
- Context and Importance: This term is central to the asserted novelty of the '133 patent's system architecture. The definition will determine whether various methods of interconnecting multiple inverters fall within the scope of the claims.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification describes the result of the daisy chain as the generated AC power being "added in parallel onto the AC powerline" ('133 Patent, col. 3:61-64). A party may argue this functional outcome is the key, suggesting any wiring scheme that achieves this parallel combination could be considered a "daisy chain."
- Evidence for a Narrower Interpretation: The claim language is structurally specific, reciting the "AC power output port of each inverter being connected... to the AC power input port of the next inverter" ('133 Patent, col. 11:43-46). This language, along with diagrams like Figure 3 showing a direct port-to-port link (52 to 51), suggests a specific physical connection is required, not just a general parallel wiring topology.
'489 Patent
- The Term: "dedicated to supply DC power"
- Context and Importance: This phrase defines the core mechanism of the claimed "low power mode." The infringement analysis for the '489 patent hinges on whether an accused inverter's power management in low light meets this "dedicated" channel requirement.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: One could argue that if an input channel becomes the de facto sole source of power for the internal electronics under certain conditions, it is functionally "dedicated," even without a formal mode switch that isolates it for that purpose.
- Evidence for a Narrower Interpretation: The specification describes a deliberate control action where the microcontroller "will select a channel... and control the corresponding DC-DC boost converter... so that it stops pulling power... for AC power generation," with its DC power then passing through to the internal power supply ('489 Patent, col. 5:31-40). This suggests a specific, programmatic repurposing of a channel, not merely a passive state.
VI. Other Allegations
- Indirect Infringement: The complaint alleges that Defendant induces infringement by providing materials such as "product manuals, brochures, videos, demonstrations, and website materials" that instruct customers on how to use the accused inverters in an infringing manner (Compl. ¶10, ¶17).
- Willful Infringement: The complaint includes a prayer for a declaration of willful infringement and treble damages (Compl., Prayer for Relief ¶e). The body of the complaint does not, however, plead specific facts alleging pre-suit knowledge of the patents or other egregious conduct.
VII. Analyst’s Conclusion: Key Questions for the Case
- An Evidentiary Question of Operation: A central issue will be whether discovery confirms that the accused Hoymiles inverters actually operate as claimed. This includes establishing whether they are installed using the specific port-to-port AC "daisy-chaining" required by the '133 patent, and whether they employ the '489 patent's "low power mode" by dedicating a single input channel to power internal electronics.
- A Definitional Question of Scope: The outcome may depend on claim construction, particularly for the term "daisy chain" in the '133 patent. The court will likely need to resolve whether this term requires the specific physical output-to-input port connection described in the patent's embodiments, or if it can be interpreted more broadly to cover other system architectures that achieve a parallel connection of inverters.
- A Procedural Question of Validity: For the '133 patent, a key issue will be the impact of the ex parte reexamination. While the confirmation of claims 15-24 may strengthen their presumption of validity, the fact that asserted independent claim 1 was not part of that reexamination leaves its validity open to challenge under a lower clear-and-convincing evidence standard than if it had been reexamined and confirmed.