System and method for flexible solar tracker and testing
Disclosed herein is a technique of configuring flexible photovoltaic tracker systems with high damping and low angle stow positions. Under dynamic environmental loads implementing a high amount of damping (e.g., greater than 25% of critical damping, greater than 50% of critical damping) or a very high amount of damping (e.g., 100% or greater of critical damping, infinite damping) enables the flexible tracker system to prevent problematic aeroelastic behaviors while positioned in a low stow angle. The disclosed technique is further applied to a prototyping process during wind tunnel testing.
1. A method of prototyping a solar tracker in a wind tunnel comprising:
determining total system damping of a flexible solar tracker system when measured under multiple conditions, wherein the flexible solar tracker system is equipped with a damper assembly that passively shift between two damping ratio stages based on damper speed, wherein a first damping ratio stage corresponding to slower damper speeds has a lesser total system damping ratio than a second damping ratio stage corresponding to faster damper speeds;
configuring the flexible solar tracker system in the wind tunnel in a low angle stow position; and
in response to said configuring, executing a dynamic loading wind tunnel test on the flexible solar tracker system that causes the damper assembly to passively shift between the two damping ratio stages.
2. The method of claim 1 , further comprising:
in response to said executing, selecting the total system damping ratio against row rotation based on results of the dynamic loading wind tunnel test.
3. The method of claim 1 , further comprising:
in response to said executing, modifying structural components of the flexible solar tracker system based on results of the dynamic loading wind tunnel test.
4. The method of claim 1 , wherein the low angle stow position is less than 20 degrees from horizontal plane.
5. The method of claim 1 , wherein said determining total system damping is based on any of:
a pluck test;
a predictive model; or
previous wind tunnel tests.
6. The method of claim 1 , wherein the total system damping ratio of the second damping ratio stage is critically damped.
7. The method of claim 1 , wherein total system damping ratio of the second damping ratio stage is overdamped.
8. The method of claim 1 , wherein the damper assembly passively shifts between damping ratio stages based on closure of a valve that reduces fluidic throughput of a damper piston.
9. The method of claim 1 , wherein the flexible solar tracker system includes substitute panels.
10. A method of prototyping a solar tracker in a wind tunnel comprising:
configuring a flexible solar tracker system in a wind tunnel in a low angle stow position, the flexible solar tracker system having a variable total system damping via a damper assembly that passively shifts between two damping ratio stages based on damper speed, wherein a first damping ratio stage corresponding to slower damper speeds causes a system damping ratio under 25% of critical damping and a second damping ratio stage corresponding to faster damper speeds causes a system damping ratio at or greater than critical damping;
in response to said configuring, executing a dynamic loading wind tunnel test on the flexible solar tracker system that causes the damper assembly to passively shift between the two damping ratio stages; and
in response to said executing, selecting the total system damping ratio against row rotation based on results of the dynamic loading wind tunnel test.
11. The method of claim 10 , further comprising:
determining a total system damping of the flexible solar tracker system when measured under peak design wind loading.
12. The method of claim 10 , further comprising:
in response to said executing, modifying structural components of the flexible solar tracker system based on results of the dynamic loading wind tunnel test.
13. The method of claim 10 , wherein measurements of loading into the damper assembly with an aeroelastic wind tunnel test or similar analysis shows the damper assembly to prevent damage resulting from an environmental wind loading.
14. The method of claim 10 , wherein the flexible solar tracker system includes substitute panels.
15. The method of claim 10 , wherein the low angle stow position is less than 20 degrees from horizontal plane.
16. A system comprising:
a flexible solar tracker system equipped with a damper assembly that passively shifts between two damping ratio stages based on damper speed, wherein a first damping ratio stage corresponding to slower damper speeds has a lesser total system damping ratio than a second damping ratio stage corresponding to faster damper speeds; and
a set of panels affixed to the flexible solar tracker and configured in a low angle stow position associated with a dynamic loading wind tunnel test on the flexible solar tracker system.
17. The system of claim 16 , wherein the low angle stow position is less than 20 degrees from horizontal plane.
18. The system of claim 16 , wherein the total system damping is predetermined based on any of:
a pluck test;
a predictive model; or
previous wind tunnel tests.
19. The system of claim 16 , wherein the total system damping ratio of the second damping ratio stage is critically damped.
20. The system of claim 16 , wherein the total system damping ratio of the second damping ratio stage is overdamped.
21. The system of claim 16 , wherein the set of panels are substitute panels.