US 10516270B2

US Patent 10516270B2, titled "Method and apparatus for coordination of generators in droop controlled microgrids using hysteresis," was filed on January 4, 2017, and issued on December 24, 2019. [cite: The full patent text confirms the filing date and publication date] The current assignee is Enphase Energy Inc. [cite: The full patent text indicates Enphase Energy Inc. as the Current Assignee and Original Assignee] The inventors are Donald Richard Zimmanck, Martin Fornage, Michael J. Harrison, and Christopher Rowe. [cite: The full patent text lists the inventors]

Abstract:
The patent describes a method and apparatus for autonomously operating a microgrid power generator. This involves obtaining a first measurement of a grid parameter (e.g., frequency) from a microgrid transmission line connected to a power generator. This first measurement is compared to a "turn-on threshold." If the measurement is below this threshold, the power generator begins generating power. After power generation starts, a second measurement of the same grid parameter is obtained. This second measurement is then compared to a "shut-down threshold" that is set higher than the turn-on threshold. If the second measurement exceeds the shut-down threshold, the power generation by the generator is stopped. [cite: The full patent text provides the abstract]

Plain-Language Overview of Independent Claims:

• Independent Claim 1 (Method): This claim describes a method for a power generator within a microgrid to operate on its own. The method involves continuously checking a grid condition (like frequency). If this condition drops below a specific "turn-on" level, the generator starts producing power. Once the generator is on, the system continues to monitor the grid condition. If the condition then rises above a different, higher "shut-down" level, the generator stops producing power. This "shut-down" level is specifically chosen to be higher than the "turn-on" level to prevent the generator from rapidly turning on and off due to the frequency changes that occur when it starts up.

• Independent Claim 7 (Apparatus): This claim describes a physical device, a "generator controller," designed to perform the autonomous operation outlined in Claim 1. The controller is equipped to measure a grid parameter (such as frequency) on a microgrid line connected to a power generator. It compares this measurement to pre-defined "turn-on" and "shut-down" thresholds. Based on these comparisons, the controller can initiate or stop the power generator's operation, ensuring the "shut-down" threshold is higher than the "turn-on" threshold to avoid instability.

• Independent Claim 15 (Non-Transitory Computer Readable Medium): This claim covers a computer program stored on a non-transitory medium (e.g., a hard drive or flash memory). When a processor executes this program, it performs the same method described in Claim 1. That is, it enables autonomous control of a microgrid power generator by monitoring a grid parameter, comparing it to "turn-on" and "shut-down" thresholds, and accordingly initiating or stopping power generation. The "shut-down" threshold is greater than the "turn-on" threshold.

USPTO and CAFC 2026 Dockets:
As of April 26, 2026, searches of the USPTO database and CAFC 2026 dockets for US patent 10516270B2 did not yield any specific docket entries or legal actions related to this patent in 2026. General information regarding USPTO search tools and CAFC case information was found. The patent's legal status is listed as "Active" and is expected to expire on November 6, 2037. [cite: The full patent text indicates "Active, expires 2037-11-06"]