Mass damper for solar tracker

• US 9,998,068 B2
• Filed: 01/29/2016
• Issued: 06/12/2018
• 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): Huson, Gregory
• Assistant Examiner(s): Namay, Daniel E
• Application Number:
  US15/011,070
• Publication Number:
  US 20160365828A1
• Time in Patent Office: 865 Days
• Field of Search: 126571, 126570, 126600, 126573, 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 system comprising;

a first pillar structure and a second pillar structure;

a torque tube configured between the first pillar structure and the second pillar structure;

a plurality of solar modules configured spatially along the 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 coupled to sandwich the torque tube between a lower portion of the clamp device and each panel rail;

a mass damper structure comprising a mechanical isolator comprising an elastic material configured to separate the panel rail from the torque tube; and

;

causing destructive interference, using the mechanical isolator, with a natural resonant frequency of the system without the mechanical isolator to reduce a mechanical vibration of the system,

wherein the mechanical isolator comprises a rubber like material having a thickness;

wherein the mechanical isolator comprises a thickness of material having one or more openings to make the mechanical isolator more flexible in characteristics, each of the openings traversing through the thickness of the mechanical isolator, each of the openings being symmetrically and spatially 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.

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

and is configured to mechanically and electrically isolate the solar module from the torque tube.

3. 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.

4. The method of claim 1 wherein the mechanical isolator comprises a material selected from a rubber material or a polymer material.

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

6. 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.

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

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

9. The method of claim 1 wherein the panel rail comprises a top-hat structure, the top hat structure comprising a top region, which has a pair of openings for the clamp device, and 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 brim region, the second brim region physically connects to the mechanical isolator, the second side characterized by a second side height and the mechanical isolator having a thickness, the second side height and the thickness are substantially equal to a first side height characterizing the first side, the mechanical isolator being coupled to an edge of a second solar module.

10. The method of claim 1 wherein the panel rail comprises a top-hat structure, the top hat structure comprising a top region, which has a pair of openings for the clamp device, 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 brim region, the second brim region physically connects to a first edge of the mechanical isolator, the second side characterized by a second side height and the mechanical isolator having a thickness, the second side height and the thickness are substantially equal to a first side height characterizing the first side, the mechanical isolator having a second edge being coupled to an edge of a second solar module;

and further comprising a polymeric or rubber bumper structure configured on either the first solar module or second solar module and provided between the first solar module and the second solar module.

11. A solar tracker method comprising:

providing a mass damper structure comprising a mechanical isolator comprising an elastic material configured to separate a panel rail from a torque tube and cause destructive interference with a natural resonant frequency of the solar tracker system without the mechanical isolator to reduce a mechanical vibration of the solar tracker system;

wherein the mechanical isolator comprises a rubber like material having a thickness;

wherein the mechanical isolator comprises a thickness of material having one or more openings to make the mechanical isolator more flexible in characteristics, each of the openings traversing through the thickness of the mechanical isolator, each of the openings being symmetrically and spatially 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,

wherein mechanical isolator has a thickness of three inches and less, and a width of two inches and less;

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;

wherein the mechanical vibration leads to failure of the solar tracker system without the mechanical isolator;

wherein the mechanical vibration is derived from external wind subjected to the solar tracker system.

12. The method of claim 11 further comprising a pair of pillars configured to hold the torque tube;

and a clamp assembly coupled to one side of the torque tube and an off-set drive coupled to the other side of the torque tube.

13. The method of claim 12 wherein the mechanical isolator is provided in one of a center solar panels spatially disposed on a panel bank comprising a plurality of solar modules disposed on the torque tube.

14. The method of claim 13 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.

15. The method of claim 14 wherein the panel bank is one of a plurality of panel banks configured on a drive assembly coupled to the torque tube.

16. The method of claim 14 wherein the other plurality of solar modules is free from any mechanical isolator.

17. The method of claim 14 wherein the mechanical isolator comprises a thickness of polymer or rubber material suitable to absorb vibration, and shock, and cause destructive interface for any natural resonance on the system.