Solar tracker system

Abstract

A photovoltaic system includes a collection of photovoltaic modules, a base supporting the collection of photovoltaic modules, and a damper coupled between the collection of photovoltaic modules and the base. The damper resists movement of the photovoltaic modules relative to the base. The damper has a first damping ratio when the collection of photovoltaic modules moves at a first rate relative to the base and a second damping ratio when the collection of photovoltaic modules moves at a second rate relative to the base, and the damper passively transitions from the first damping ratio to the second damping ratio.

What is claimed is: 
     
         1 . A system comprising:
 a photovoltaic module; and   a damper coupled to the photovoltaic module, the damper including a variable damping ratio that varies as a function of a current loading force on the photovoltaic module, wherein the photovoltaic module experiences loading forces in response to environmental stress and in response to positional adjustment via an actuator, and wherein the variable damping ratio is a first damping ratio in response to the environmental stress and a second damping ratio in response to the positional adjustment via the actuator.   
     
     
         2 . The system of  claim 1 , wherein the photovoltaic module is a first module in an array of photovoltaic modules that are each individually damped. 
     
     
         3 . The system of  claim 1 , wherein the damping ratio increases in response to increases in current loading force. 
     
     
         4 . The system of  claim 3 , wherein the damper further comprises:
 a piston driven by the current loading force on the photovoltaic module; and   a piston chamber including a non-Newtonian fluid that increases in viscosity relative to the current loading force driving the piston.   
     
     
         5 . The system of  claim 3 , wherein the damper further comprises:
 a piston driven by the current loading force on the photovoltaic module and including a variable vent size based on the current loading force; and   a piston chamber including a fluid that resists motion of the piston, wherein the fluid is displaced in response to movement of the piston via a vent having the variable vent size.   
     
     
         6 . The system of  claim 5 , wherein the variable vent size decreases in response to increases in the current loading force. 
     
     
         7 . The system of  claim 1 , wherein a certain current loading force causes a damping ratio that fully locks movement of the damper. 
     
     
         8 . The system of  claim 1 , further comprising:
 an actuator configured to position the photovoltaic module using a low current loading force with a corresponding low damping ratio.   
     
     
         9 . A photovoltaic system, comprising:
 a photovoltaic module;   a mount affixed to the photovoltaic module and configured to enable the photovoltaic module to pivot about an axis;   an actuator configured to pivot an angular position of the photovoltaic module about the axis and relative to the mount; and   a damper coupled to the photovoltaic module and resisting angular position adjustment of the photovoltaic module, wherein the damper exhibits a variable damping ratio as a function of a current loading condition of the photovoltaic module, wherein the photovoltaic module experiences loading conditions in response to environmental stress and in response to positional adjustment via an actuator, and wherein the variable damping ratio is a first damping ratio in response to the environmental stress and a second damping ratio in response to the positional adjustment via the actuator.   
     
     
         10 . The system of  claim 9 , wherein the damping ratio increases in response to increases in the current loading condition. 
     
     
         11 . The system of  claim 10 , wherein the damper further comprises:
 a piston driven by the current loading condition on the photovoltaic module; and   a piston chamber including a non-Newtonian fluid that increases in viscosity relative to the current loading condition driving the piston.   
     
     
         12 . The system of  claim 10 , wherein the damper further comprises:
 a piston driven by the current loading condition on the photovoltaic module and including a variable vent size based on the current loading condition; and   a piston chamber including a fluid that resists motion of the piston, wherein the fluid is displaced in response to movement of the piston via a vent having the variable vent size.   
     
     
         13 . The system of  claim 12 , wherein the variable vent size decreases in response to increases in the current loading force. 
     
     
         14 . The system of  claim 9 , wherein a certain current loading condition causes a damping ratio that fully locks movement of the damper. 
     
     
         15 . A method comprising:
 setting, by an actuator, an angular position of a photovoltaic module about an axis and relative to a mount; and   resisting angular position adjustment, by a damper of the photovoltaic module, wherein said resisting applies a variable damping ratio as a function of a current loading condition on the photovoltaic module, wherein the photovoltaic module experiences loading conditions in response to environmental stress and in response to positional adjustment via an actuator, and wherein the variable damping ratio is a first damping ratio in response to the environmental stress and a second damping ratio in response to the positional adjustment via the actuator.   
     
     
         16 . The method of  claim 15 , wherein the damping ratio increases in response to increases in force of the current loading condition. 
     
     
         17 . The method of  claim 15 , wherein the damping ratio increases in response to increases in the current loading condition. 
     
     
         18 . The method of  claim 17 , wherein said resisting further comprises:
 driving a piston driven by the current loading condition on the photovoltaic module; and   increasing viscosity, of a non-Newtonian included inside a piston chamber, relative to the current loading condition driving the piston.   
     
     
         19 . The method of  claim 17 , wherein said resisting further comprises:
 driving a piston by the current loading condition on the photovoltaic module and including a variable vent size based on the current loading condition; and   displacing a fluid included in a piston chamber through a vent of the piston in response to said driving the piston at a variable rate based on the variable vent size.   
     
     
         20 . The method of  claim 19 , wherein the variable vent size decreases in response to increases in the current loading force. 
     
     
         21 . The method of  claim 15 , further comprising:
 in response to a certain current loading condition, fully locking movement of the damper.