US 11,757,286 B2
Method and system for providing renewable energy plant frequency response
Dmitriy Anichkov, Somerville, NJ (US)
Assigned to MERIT SI, LLC, Annandale, NJ (US)
Appl. No. 17/40,566
Filed by MERIT SI, LLC, Annandale, NJ (US)
PCT Filed Apr. 22, 2019, PCT No. PCT/US2019/028489
§ 371(c)(1), (2) Date Sep. 23, 2020,
PCT Pub. No. WO2019/209701, PCT Pub. Date Oct. 31, 2019.
Claims priority of provisional application 62/662,307, filed on Apr. 25, 2018.
Prior Publication US 2021/0066925 A1, Mar. 4, 2021
Int. Cl. H02J 3/38 (2006.01); H02J 3/06 (2006.01); H02J 3/16 (2006.01); F03D 9/25 (2016.01)
CPC H02J 3/381 (2013.01) [F03D 9/255 (2017.02); H02J 2300/20 (2020.01)] 17 Claims
OG exemplary drawing
 
1. A method for providing frequency response for a renewable energy plant coupled to an electric power grid, the renewable energy plant having an intermittent energy source, the method comprising:
using a renewable energy plant control system, measuring frequency of the power output from the renewable energy plant and determining a first difference signal between the measured frequency and a frequency reference;
measuring power output from the renewable energy plant and storing the measured power output as a stored measured power output value;
while the first difference signal is within a predetermined frequency deviation deadband, determining a second difference signal as a difference between a power reference and the measured power output;
while the first difference signal indicates an over-frequency condition, determining the second difference signal as a difference between the stored measured power output value and the measured power output;
while the first difference signal indicates an under-frequency condition, setting the second difference signal equal to the power reference;
generating an error signal by limiting a sum of the first and second difference signals between predetermined minimum and maximum power error limits;
generating a control signal by applying the error signal to a controller; and,
applying the control signal to the intermittent energy source to control the power output therefrom.