Mass damper for solar tracker

• US 10,601,365 B2
• Filed: 05/14/2018
• Issued: 03/24/2020
• Est. Priority Date: 06/09/2015
• Status: Active Grant

• Current Assignee: Nextracker
• Original Assignee: NEXTracker, Inc. (Flex, Ltd.)
• Inventors: Au, Alexander W.
• Primary Examiner(s): McAllister, Steven B
• Assistant Examiner(s): Namay, Daniel E.
• Application Number:
  US15/979,368
• Publication Number:
  US 20190140583A1
• Time in Patent Office: 680 Days
• Field of Search: 126571, 126570, 126600, 745744, 248638
• CPC Class Codes: F16F 1/36 made of rubber or other material having high internal friction, e.g. thermoplastic elastomers spring units consisting of several springs F16F3/08
• CPC Class Codes: F16F 15/08 with rubber springs grommet- or bushing-type resilient mountings F16F1/3732, F16F1/38; with springs made of rubber and metal arrangement of internal-combustion or jet-propulsion units B60K5/12; mounting of propulsion plants on vessels B63H21/30; mounting of vehicle drivers' cabs B62D33/0604
• CPC Class Codes: F16M 11/04 Means for attachment of apparatus; Means allowing adjustment of the apparatus relatively to the stand
• CPC Class Codes: F24S 2025/6003 by clamping
• CPC Class Codes: F24S 2030/19 Movement dampening means; Braking means
• CPC Class Codes: F24S 25/65 for coupling adjacent supporting elements, e.g. for connecting profiles together
• CPC Class Codes: F24S 30/425 Horizontal axis
• CPC Class Codes: F24S 40/85 Arrangements for protecting solar collectors against adverse weather conditions F24S40/10 takes precedence
• CPC Class Codes: H02S 20/32 specially adapted for solar tracking
• CPC Class Codes: H02S 30/10 Frame structures
• CPC Class Codes: Y02B 10/70 Hybrid systems, e.g. uninterruptible or back-up power supplies integrating renewable energies
• CPC Class Codes: Y02E 10/47 Mountings or tracking
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy

Abstract

In an example, the system has a mechanical isolator comprising an elastic material configured to separate the panel rail from the torque tube cause destructive interference with a natural resonant frequency of the system without the mechanical isolator to reduce a mechanical vibration of the system.

Claims

1. A method of operating a solar tracker system, comprising:

providing the solar tracker system comprising;

a plurality of solar modules configured spatially along a torque tube from a first end to a second end;

a panel rail configured to support each of the plurality of solar modules;

a clamp device configured to couple each panel rail to the torque tube; and

a mass damper structure comprising a mechanical isolator comprising an elastic material coupled between a panel rail and the torque tube; and

causing destructive interference, using the mechanical isolator, with a natural resonant frequency of the solar tracker system.

2. The method of claim 1, wherein the elastic material comprises a rubber-like material having a thickness, and

wherein the mechanical isolator comprises a thickness of material having an opening, the opening traversing through the thickness of the mechanical isolator the opening being disposed along a length of the mechanical isolator, the mechanical isolator being characterized by a narrow region along a center of the length in relationship to each edge region of the mechanical isolator.

3. The method of claim 1, wherein the mechanical isolator has a thickness of three inches or less and a width of two inches or less, and

wherein the mechanical isolator is configured to mechanically isolate the solar module from the torque tube.

4. The method of claim 1, wherein the natural resonant frequency ranges from 1 Hz to 10 Hz in a torsional mode and 1 Hz to 5 Hz in a bending mode.

5. The method of claim 1, wherein the elastic material comprises a rubber material or a polymer material.

6. The method of claim 1, wherein the mechanical vibration leads to failure of the solar tracker system without the mechanical isolator.

7. The method of claim 1, wherein the mechanical isolator comprises a stiffness to tune a mass and an inertia of the tracker system to reduce the mechanical vibration.

8. The method of claim 1, wherein the mechanical vibration comprises a torsional mode and a bending mode.

9. The method of claim 1, wherein the mechanical vibration is derived from external wind subjected to the solar tracker system.

10. The method of claim 1, wherein the panel rail includes a first side coupled to an edge of a first solar module and a second side coupled to the mechanical isolator, the second side having a second side height and the mechanical isolator having a thickness, the second side height and the thickness being substantially equal to a first side height of the first side, the mechanical isolator being coupled to an edge of a second solar module.

11. The method of claim 10, further comprising a polymeric or rubber bumper structure configured on either the first solar module or the second solar module and provided between the first solar module and the second solar module.

12. A solar tracker comprising:

a panel rail configured to support a solar module;

a torque tube coupled to the panel rail; and

a mass damper structure comprising a mechanical isolator comprising an elastic material coupled between a panel rail and a torque tube and configured to cause destructive interference with a natural resonant frequency of the solar tracker;

wherein the mechanical isolator comprises a rubber-like material having a thickness,

wherein the mechanical isolator comprises a thickness of material having an opening, the opening traversing through the thickness of the mechanical isolator, the mechanical isolator having a narrow region at a center of the mechanical isolator in relationship to each edge region of the mechanical isolator, and

wherein the natural resonant frequency ranges from 1 Hz to 10 Hz in a torsional mode and 1 Hz to 5 Hz in a bending mode.

13. The solar tracker of claim 12, further comprising:

a pair of piers configured to support the torque tube;

a clamp assembly coupled to a first side of the torque tube; and

an off-set drive coupled to a second side of the torque tube.

14. The solar tracker of claim 13, wherein the mechanical isolator is provided in a center solar panel spatially disposed on a panel bank comprising a plurality of solar modules disposed on the torque tube.

15. The solar tracker of claim 14, wherein the panel bank is configured between the pair of piers, each of the piers configured with a clamp assembly coupled to the torque tube.

16. The solar tracker of claim 15, wherein the panel bank is one of a plurality of panel banks configured on a drive assembly coupled to the torque tube.

17. The solar tracker of claim 15, wherein the other plurality of solar modules is free from a mechanical isolator.

18. The solar tracker of claim 15, wherein the mechanical isolator comprises a thickness of polymer or rubber material suitable to absorb vibration and shock, and cause destructive interference for any natural resonance on the solar tracker.

19. The solar tracker of claim 12, wherein the mechanical isolator symmetrically flares out from the center to the edge regions of the mechanical isolator.

20. The solar tracker of claim 12, wherein the mechanical isolator further comprises a flange disposed at each of the edge regions of the mechanical isolator.