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US 12,719,405 B2Granted
Learning axis-tilt and cross-axis slopes for slope-aware backtracking
AssigneeArray Tech, Inc.
InventorsJohn Moseley, Kyumin Lee, Kendra Lynn Conrad
Life of this patent
Estimating the term…
Abstract
Embodiments of the present disclosure may provide improvements over existing solar tracking systems by implementing a backtracking process that optimizes irradiance capture while also reducing row-to-row shading. In some embodiments, a “slope-aware” backtracking model accounts for east-west and north-south slopes that are present, as in uneven or hilly terrain.
Claims22
A method for learning axis-tilt and cross-axis slopes for slope-aware backtracking in single-axis solar tracking systems, the method comprising:
- monitoring an amount of power produced by a photovoltaic (PV) panel on a tracker axis during a first learning period by maintaining the PV panel at a learning angle to identify a first knee timestamp on a first backtracking curve for the PV panel;
- monitoring an amount of power produced by the PV panel on the tracker axis during a second learning period by maintaining the PV panel at the same learning angle to identify a second knee timestamp on a second backtracking curve for the PV panel, wherein the first learning period and the second learning period occur at different times of a year;
- determining a solar azimuth angle and solar zenith angle for the first knee timestamp;
- determining a solar azimuth angle and solar zenith angle for the second knee timestamp;
- transforming the solar azimuth and solar zenith angles for the first knee timestamp and the solar azimuth and solar zenith angles for the second knee timestamp into a cartesian coordinate system and rotating the transformed solar coordinates into a tracker reference frame;
- determining an axis-tilt angle;
- determining a projected solar zenith angle;
- determining a limiting cross-axis slope, wherein determining the limiting cross-axis slope includes an evaluation of the following equation:
- Δ
-
- R
- =
- sgn
-
- θ
- PSZ
-
- cos
- -
- 1
-
- {
- P
- L
- m
- ·
- (
- cos
-
- θ
- PSZ
- -
- m
- lim
-
- sin
-
- θ
- PSZ
- )
- }
- ;
- determining, based on the axis-tilt angle and the limiting cross-axis slope, a plurality of backtracking angles for the tracker axis by varying known solar azimuth and solar zenith angles to create a backtracking curve;
- and
- rotating the PV panel on the tracker axis according to the backtracking curve.
42 more elements
A method for learning axis-tilt and cross-axis slopes for slope-aware backtracking in single-axis solar tracking systems, the method comprising:
- monitoring an amount of power produced by a photovoltaic (PV) panel on a tracker axis during a single learning period using a first learning angle to identify a first knee timestamp on a backtracking curve for the PV panel;
- monitoring an amount of power produced by the PV panel on the tracker axis during the same learning period using a second learning angle to identify a second knee timestamp on the same backtracking curve for the PV panel, wherein the first learning angle and the second learning angle are different angles;
- determining a solar azimuth angle and solar zenith angle for the first knee timestamp;
- determining a solar azimuth angle and solar zenith angle for the second knee timestamp;
- transforming the solar azimuth and solar zenith angles for the first knee timestamp and the solar azimuth and solar zenith angles for the second knee timestamp into a cartesian coordinate system and rotating into the tracker reference frame;
- determining an axis-tilt angle;
- determining a limiting cross-axis slope;
- wherein determining the limiting cross-axis slope includes evaluating the following equations:
- R
- 1
- =
- θ
- PSZ
-
- _
-
- 1
- -
- sgn
-
- θ
- PSZ
-
- _
-
- 1
-
- cos
- -
- 1
-
- {
- P
- L
- m
- ·
- (
- cos
-
- θ
- PSZ
-
- _
-
- 1
- -
- m
- lim
-
- sin
-
- θ
- PSZ
-
- _
-
- 1
- )
- }
- R
- 2
- =
- θ
- PSZ
-
- _
-
- 2
- -
- sgn
-
- θ
- PSZ
-
- _
-
- 2
-
- cos
- -
- 1
-
- {
- P
- L
- m
- ·
- (
- cos
-
- θ
- PSZ
-
- _
-
- 2
- -
- m
- lim
-
- sin
-
- θ
- PSZ
-
- _
-
- 2
- )
- }
- ;
- determining, based on the axis-tilt angle and the limiting cross-axis slope, a plurality of backtracking angles for the tracker axis by varying known solar azimuth and solar zenith angles to create a backtracking curve;
- and
- rotating the PV panel on the tracker axis according to the backtracking curve.
111 more elements
Dependencies are inferred from the claim text.