IP Library Granted Patent US 12,362,572
Granted Patent B2
US 12,362,572 · App. 18/668,797 · Granted Jul 15, 2025

Systems and methods for photovoltaic production curtailment and autonomous load breaking

Inventors: Brian Kuhn (Austin, TX); Sandeep Narla (Newark, CA)
Assignee: Unirac, Inc.
H02J3/381H02J3/14H02J3/32H02J9/06H02J2300/24
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Quick Facts
Patent No.
US 12,362,572
App. No.
18/668,797
Granted
Jul 15, 2025
Kind
B2
Abstract

The present disclosure provides curtailing photovoltaic (PV) power output and autonomous load breaking in a backup mode of an electrical system. The electrical system includes a PV system, an energy storage system having a storage converter, and an energy control system. The energy control system is electrically coupled to the PV system, the energy storage system, and a plurality of backup loads. The electrical system includes an autonomous load breaker electrically coupled to a first backup load. When the energy control system switches from an on-grid mode to the backup mode, the storage converter adjusts the frequency of the power supplied to the backup side of the energy control system to a setpoint frequency that curtails PV power output, and the autonomous load breaker electrically disconnects the first backup load from the energy control system.

Claims (40)

1. An electrical system, comprising:

an energy control system electrically coupled to a plurality of backup loads including a first backup load;

a photovoltaic (PV) power generation system electrically coupled to the energy control system, the PV power generation system configured to generate and supply power;

an energy storage system electrically coupled to the energy control system, the energy storage system configured to store power supplied by the PV power generation system and discharge stored power to the energy control system; and

an autonomous smart load breaker electrically coupled to the first backup load,

wherein the energy control system is configured to operate in an on-grid mode electrically connecting the PV power generation system to a utility grid and a backup mode electrically disconnecting the PV power generation system and the plurality of backup loads from the utility grid,

wherein the autonomous smart load breaker is configured to:

detect changes in a frequency of power supplied to the energy control system, wherein the frequency is adjusted by the energy storage system during discharge of the stored power to the first backup load;

connect the first backup load with the energy control system when the frequency is in a first frequency range to increase PV power output; and

disconnect the first backup load from the energy control system when the frequency is in a second frequency range to curtail PV power output.

2. The electrical system of claim 1 , wherein the autonomous smart load breaker comprises a switch and a microcontroller configured to operate the switch.

3. The electrical system of claim 1 , wherein the autonomous smart load breaker comprises an electro-mechanical relay.

4. The electrical system of claim 1 , wherein the autonomous smart load breaker comprises a solid-state switch.

5. The electrical system of claim 1 , wherein the autonomous smart load breaker comprises measurement circuitry configured to detect at least one of voltage and current, and the autonomous smart load breaker is configured to determine whether to disconnect the first backup load from the energy control system based on the detected voltage or current.

6. The electrical system of claim 1 , wherein the first frequency range emulates frequency of power supplied by a utility grid to increase PV power output.

7. The electrical system of claim 1 , wherein the second frequency range is different from the first frequency range to curtail PV power output.

8. An electrical system comprising:

an energy control system configured to operate in an on-grid mode electrically connecting a PV power generation system to a utility grid and a backup mode electrically disconnecting the PV power generation system and a plurality of backup loads from the utility grid;

an autonomous smart load breaker comprising a microcontroller configured to:

detect changes in a frequency of power supplied to the energy control system, wherein the frequency is adjusted by an energy storage system during discharge of stored power to a first backup load of the plurality of backup loads;

connect the first backup load with the energy control system when the frequency is in a first frequency range to increase photovoltaic (PV) power output; and

disconnect the first backup load from the energy control system when the frequency is in a second frequency range to curtail PV power output.

9. The autonomous smart load breaker of claim 8 , further comprising a switch, wherein a microcontroller of the microcontroller is configured to operate the switch.

10. The autonomous smart load breaker of claim 8 , further comprising an electro-mechanical relay.

11. The autonomous smart load breaker of claim 8 , further comprising a solid-state switch.

12. The autonomous smart load breaker of claim 8 , wherein the first frequency range emulates frequency of power supplied by the utility grid to increase PV power output.

13. The autonomous smart load breaker of claim 8 , wherein the second frequency range is different from the first frequency range to curtail PV power output.

14. The autonomous smart load breaker of claim 8 , further comprising measurement circuitry configured to detect at least one of voltage and current, wherein the autonomous smart load breaker is configured to determine whether to disconnect the first backup load from the energy control system based on the detected voltage or current.

15. A computer-implemented method comprising under control of an energy control system configured to execute specific steps:

operating in an on-grid mode electrically connecting a PV power generation system to a utility grid; and

operating in a backup mode electrically disconnecting the PV power generation system and a plurality of backup loads from the utility grid;

under control of a microcontroller associated with an autonomous smart load breaker, the microcontroller configured to execute specific steps:

detecting changes in a frequency of power supplied to an energy control system, wherein the frequency is adjusted by an energy storage system during discharge of stored power to a first backup load of the plurality of backup loads;

connecting the first backup load with the energy control system when the frequency is in a first frequency range to increase photovoltaic (PV) power output; and

disconnecting the first backup load from the energy control system when the frequency is in a second frequency range to curtail PV power output.

16. The computer-implemented method of claim 15 , further comprising operating a switch of the autonomous smart load breaker.

17. The computer-implemented method of claim 15 , wherein connecting the first backup load with the energy control system when the frequency is in a first frequency range to increase PV power output further comprises connecting the first backup load with the energy control system when the frequency is in the first frequency range that emulates frequency of power supplied by a utility grid to increase PV power output.

18. The computer-implemented method of claim 15 , wherein disconnecting the first backup load from the energy control system when the frequency is in a second frequency range to curtail PV power output further comprises disconnecting the first backup load from the energy control system when the frequency is in the second frequency range that is different from the first frequency range to curtail PV power output.

19. The computer-implemented method of claim 15 , further comprising disrupting an electrical connection between the energy control system and the first backup load within a predetermined time period.

20. The computer-implemented method of claim 19 , wherein disrupting the electrical connection between the energy control system and the first backup load within the predetermined time period further comprises disrupting the electrical connection within a response time in a range between approximately 10 milliseconds and approximately 40 milliseconds.

Assignments (4)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 16, 2025
From: SUNPOWER CORPORATION; SUNPOWER CORPORATION, SYSTEMS
To: UNIRAC, INC.
Reel/Frame 071302/0904 →
RELEASE OF SECURITY INTEREST Recorded Apr 1, 2025
From: SUNPOWER CORPORATION,
To: UNIRAC, INC.
Reel/Frame 070704/0860 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Nov 18, 2024
From: SUNPOWER CORPORATION
To: UNIRAC, INC.
Reel/Frame 069380/0745 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 20, 2024
From: KUHN, BRIAN; NARLA, SANDEEP
To: SUNPOWER CORPORATION
Reel/Frame 067465/0958 →
Continuity (3)
Division 17587482 · Jan 28, 2022
Provisional Application 63144256 · Feb 1, 2021
Related Publication 20240305108A1 · Sep 12, 2024
References Cited (5)
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US 20160190810A1 · Bhavaraju et al. · 2016 [cited by applicant]
US 20180048159A1 · Narla et al. · 2018 [cited by applicant]
US 20200336003A1 · Narla · 2020 [cited by examiner]