DCT

2:24-cv-01270

PSLC LLC v. Generac Power Systems Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:24-cv-01270, E.D. Wis., 10/07/2024
  • Venue Allegations: Plaintiff alleges venue is proper in the Eastern District of Wisconsin because Defendant maintains its principal place of business in Waukesha, WI, and operates multiple manufacturing facilities within the district.
  • Core Dispute: Plaintiff alleges that Defendant’s backup power and load management products, including the Generac PWRcell Systems, infringe three patents related to proactive power source load control.
  • Technical Context: The technology addresses the management of electrical loads for backup power sources, such as generators or battery systems, to prevent overloads and allow for the use of smaller, more efficient power sources.
  • Key Procedural History: The complaint alleges that the inventor made Defendant aware of his inventions through communications beginning in 2012 and specifically notified Defendant of two of the patents-in-suit in January 2021. The complaint also notes that one of the patents-in-suit was cited by a patent examiner as grounds for a rejection during the prosecution of one of Defendant’s own patents, which may be presented as evidence of pre-suit knowledge.

Case Timeline

Date Event
2011-05-26 Priority Date for ’727, ’618, and ’857 Patents
2012-02-14 Inventor's first alleged communication with Defendant
2012-03-15 Inventor's alleged follow-up communication with Defendant
2020-12-29 U.S. Patent No. 10,879,727 Issued
2021-01-12 U.S. Patent No. 10,892,618 Issued
2021-01-24 Inventor's alleged communication notifying Defendant of ’727 and ’618 Patents
2021-07-29 Defendant's U.S. Patent No. 11,831,197 Filed (prosecution history mentioned in complaint)
2024-04-23 U.S. Patent No. 11,967,857 Issued
2024-10-07 Complaint Filed

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

U.S. Patent No. 10,879,727 - "POWER SOURCE LOAD CONTROL" (Issued Dec. 29, 2020)

The Invention Explained

  • Problem Addressed: The patent's background describes the problem of sizing backup power sources. Conventional systems often required oversized, inefficient generators to handle the maximum potential electrical load, or they employed reactive load-shedding systems that only disconnected loads after an overload had already occurred, risking damage to the generator or connected devices (Compl. ¶¶16, 18; ’727 Patent, col. 2:15-18).
  • The Patented Solution: The invention proposes a proactive method for controlling the load presented to a power source by intelligently and selectively connecting or disconnecting loads to keep the total load below the source's maximum output capability (Compl. ¶11; ’727 Patent, Abstract). This is achieved through a "Load Control" unit that monitors the power source and controls individual "Load Switches" connected to various appliances, as illustrated in the patent's Figure 4, allowing smaller, more efficient power sources to be used without risk of overload (’727 Patent, Fig. 4).
  • Technical Importance: This approach allows for the creation of more affordable, reliable, and efficient backup power systems for residential and small business use (Compl. ¶16).

Key Claims at a Glance

  • The complaint asserts independent claim 37 (Compl. ¶28).
  • Claim 37 is an apparatus claim comprising these essential elements:
    • A backup power system transfer switch controllable to select between a power grid circuit and a DC to AC Inverter powered by a battery.
    • A processor circuit programmed to control the system to power loads (including a battery charger) from the grid when grid power is acceptable.
    • The processor circuit is further programmed to cause loads, but not the battery charger, to be powered by the DC to AC Inverter when grid power is unacceptable.
    • The processor circuit is also programmed to timely monitor the current provided by the inverter to the loads and prevent its maximum current capacity from being exceeded.
  • The complaint reserves the right to assert other claims (Compl. ¶31).

U.S. Patent No. 10,892,618 - "POWER SOURCE LOAD CONTROL" (Issued Jan. 12, 2021)

The Invention Explained

  • Problem Addressed: The patent addresses the challenge of managing loads for a backup power system that is not capable of simultaneously powering all connected loads in a home or business (’618 Patent, col. 15:15-17).
  • The Patented Solution: The invention describes a backup power system with a "load coupler" that contains a processor circuit and a contactor for controlling power to a specific load (’618 Patent, Claim 17). The system is designed to allow an installer to configure its operation via a user input circuit. The processor is programmed to proactively shed the load in response to a potential overload of the backup power source and then re-supply power after a known time period that is responsive to the installer's configuration (’618 Patent, Claim 17(d)-(e)).
  • Technical Importance: This technology provides an intelligent and installer-configurable method for managing individual high-power loads, improving the safety and reliability of smaller backup power systems (Compl. ¶42).

Key Claims at a Glance

  • The complaint asserts independent claim 17 (Compl. ¶40).
  • Claim 17 is a system claim comprising these essential elements:
    • A second power source (backup) not capable of powering all loads simultaneously.
    • A transfer switch to select between a primary and the second power source.
    • A "first load coupler" which itself includes: (a) a contactor, (b) a power supply for a processor, (c) the processor circuit for controlling the contactor, (d) a user input circuit for an installer to configure the coupler, and (e) programming for the processor to cause a load shed on potential overload and resupply power after a known, installer-configured time period.
  • The complaint reserves the right to assert other claims (Compl. ¶43).

U.S. Patent No. 11,967,857 - "POWER SOURCE LOAD CONTROL" (Issued Apr. 23, 2024) (Multi-Patent Capsule)

Technology Synopsis

This patent describes a power system that uses the frequency of its AC power output as a communication signal to manage loads (Compl. ¶52). The system's inverter operates at a first frequency (e.g., 60 Hz) during normal operation but shifts to a second, lower frequency (e.g., 58 Hz) when it is overloaded or nearing an overload condition. This frequency shift signals a processor circuit to control or disconnect loads to prevent or alleviate the overload (Compl. ¶54; ’857 Patent, Claim 1).

Asserted Claims

The complaint asserts independent claim 1 (Compl. ¶52).

Accused Features

The complaint alleges that the Generac PWRcell Inverter monitors its output power and, when overloaded, changes its output frequency to signal the PWRmanager and/or Smart Management Modules (SMMs) to disconnect loads (Compl. ¶54).

III. The Accused Instrumentality

Product Identification

The accused instrumentalities are the Generac PWRcell Systems, which include various components such as the PWRManager, PWRcell Battery, PWRcell Inverter, PV Link Substring Optimizer, PWRcell Automatic Transfer Switch (ATS), PWRGenerator, Smart Management Modules (SMMs), and the PWRView App (Compl. ¶21).

Functionality and Market Context

The accused products constitute a backup power system for homes and businesses, often integrated with solar photovoltaic arrays (Compl. ¶22). The complaint alleges that the PWRcell Inverter converts DC power from the PWRcell Battery or a solar array into AC power for household loads during a grid outage. The PWRcell ATS manages the switchover from grid power to backup power (Compl. ¶22). The PWRmanager and SMMs are identified as the load control devices used to prevent the Inverter from being overloaded by managing which loads are powered (Compl. ¶23). The complaint uses a system diagram from a Generac installation manual, Figure 8-1, to illustrate the interconnection and operation of these components (Compl. ¶29).

IV. Analysis of Infringement Allegations

’727 Patent Infringement Allegations

Claim Element (from Independent Claim 37) Alleged Infringing Functionality Complaint Citation Patent Citation
(a) a small backup power system transfer switch which is controllable to select a power grid service circuit or a DC to AC Inverter to power a group of loads... The PWRcell ATS, which selects between the AC grid and the PWRcell Inverter to power loads. ¶30 col. 10:25-30
(b) a processor circuit being programmed to control the transfer switch and the DC to AC Inverter to power... loads... from the power grid when the power grid operates at an acceptable voltage... Processors located in the PWRcell Inverter and PWRmanager control the system to use grid power when available. ¶30 col. 10:25-30
...and to cause the one or more loads... but not the battery charger to be powered by the DC to AC Inverter when the power grid does not operate at the acceptable voltage; When the grid is down, DC power from the PWRcell Battery is converted by the Inverter to AC power for the loads. ¶30 col. 10:25-30
(c) the processor circuit being programmed to timely monitor the current provided to the loads by said DC to AC Inverter and to prevent exceeding the maximum current capacity of the DC to AC Inverter. The processor circuit monitors the Inverter's output to prevent overloads. ¶30 col. 10:31-35
  • Identified Points of Contention:
    • Scope Questions: A central question may be whether the system's distributed processing capabilities (located on the Inverter and in the PWRmanager) collectively meet the "a processor circuit" limitation of the claim (Compl. ¶30).
    • Technical Questions: What evidence does the complaint provide that the accused system performs the negative limitation of powering loads "but not the battery charger" from the inverter when the grid is down, as required by claim 37(b)? The complaint's allegations focus on the affirmative powering of loads but are less specific on this point (Compl. ¶30).

’618 Patent Infringement Allegations

Claim Element (from Independent Claim 17) Alleged Infringing Functionality Complaint Citation Patent Citation
a second power source... not being capable of simultaneously powering all of the loads... The PWRcell Inverter, which is allegedly not capable of powering all loads simultaneously, as evidenced by the presence of the PWRmanager for load control. ¶42 col. 15:15-17
a transfer switch having an output, a first input coupled to a first power source and a second input coupled to the second power source... The PWRcell ATS, which is coupled to the grid (first source) and the Inverter (second source) and has an output to the loads. ¶42 col. 15:18-23
a first load coupler comprising: ...a) a contactor... The PWRmanager or SMMs, which are alleged to be a load coupler comprising a contactor. ¶42 col. 16:1-5
d) a user input circuit coupled to the processor circuit and enabling a user who is an installer to configure the first load coupler... The system allegedly includes a WiFi Access Point that allows an installer to configure the load coupler to operate with the first load via a mobile device. ¶42 col. 16:11-14
e) the processor circuit being programmed to cause a load shed... and further operating to close the contactor to resupply power to the first load after at least a known time period... The processor circuit is programmed to shed loads to avoid an overload and resupply power after a set period of time. ¶42 col. 16:15-23
  • Identified Points of Contention:
    • Scope Questions: Does the accused "PWRmanager or SMMs" architecture meet the structural and functional definition of the claimed "first load coupler"? (Compl. ¶42).
    • Technical Questions: The complaint alleges the system resupplies power after a "set period of time," but does it provide sufficient factual basis to show this time period is specifically "responsive to the first load coupler configuration by the installer" as required by claim 17(e)? (Compl. ¶42).

V. Key Claim Terms for Construction

  • The Term: "small backup power system transfer switch" (’727 Patent, claim 37(a))
    • Context and Importance: The construction of this term is central to whether the patent, which illustrates simpler generator-based backups, applies to the accused modern, integrated solar and battery storage systems. Practitioners may focus on this term because Defendant may argue its sophisticated PWRcell ATS is not the "small" or simple component contemplated by the patent.
    • Intrinsic Evidence for a Broader Interpretation: The patent specification states that "Generator" is intended to encompass a wide range of power sources, including "solar panels, fuel cells, flywheels, batteries," and may incorporate a "DC to AC Inverter circuit," which aligns with the technology of the accused system (’727 Patent, col. 13:43-49).
    • Evidence for a Narrower Interpretation: The patent's background section and figures (e.g., Figs. 1-3) primarily discuss and depict prior art based on traditional internal combustion generators, which may suggest the invention was conceived in a narrower technological context (’727 Patent, col. 5:10-25; Figs. 1-3).
  • The Term: "load coupler" (’618 Patent, claim 17)
    • Context and Importance: Infringement of claim 17 hinges on whether the accused PWRmanager and/or SMMs embody this claimed element. The dispute may turn on whether the accused products, which manage loads, meet the specific structural and functional requirements laid out for the "load coupler" in the claim itself.
    • Intrinsic Evidence for a Broader Interpretation: Claim 17 itself provides a detailed definition of the "load coupler" by listing its required sub-components (contactor, processor, user input, etc.). Plaintiff may argue that any device containing these components and performing their functions is a "load coupler," regardless of its name.
    • Evidence for a Narrower Interpretation: The patent depicts a "Load Coupler" as a discrete component in a block diagram (e.g., "Load Coupler 80" in Fig. 13 of the patent family), which could be used to argue that the distributed architecture of the accused PWRmanager and SMMs does not meet the definition (’618 Patent, Fig. 13).

VI. Other Allegations

  • Indirect Infringement: The complaint alleges inducement based on Defendant’s user manuals and installation instructions, which allegedly instruct customers on how to set up and operate the accused products in an infringing manner (Compl. ¶¶33, 45, 57). It also alleges contributory infringement on the grounds that the accused products are especially designed for this use and have no substantial non-infringing use (Compl. ¶¶34, 46, 58).
  • Willful Infringement: Willfulness is alleged based on Defendant's alleged pre-suit knowledge of the patents. The complaint cites multiple alleged communications from the inventor to Defendant, including a January 2021 letter that specifically identified the ’727 and ’618 Patents (Compl. ¶¶12-13). It further alleges that the ’727 Patent was cited against Defendant during the prosecution of its own patent application, constituting actual notice (Compl. ¶13).

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

  • A core issue will be one of definitional scope: can claim terms such as "small backup power system" and "load coupler," rooted in the patent's context of traditional generator-based systems, be construed to cover the technologically distinct components of Defendant's modern, integrated solar and battery storage systems?
  • A key evidentiary question will be one of functional proof: does the complaint and subsequent discovery provide sufficient technical evidence that the accused Generac systems perform the specific, nuanced functions required by the asserted claims, such as the negative limitation of not powering the battery charger from the inverter (in the '727 patent) or making a post-shed reconnection time dependent on an installer's configuration (in the '618 patent)?