Solar monitor for solar device

Abstract

A solar monitor measures electrical characteristics of a designated solar device within an array of solar devices that are coupled in series. The solar monitor includes a charge storage element and a charger coupled to the charge storage element to establish a positive voltage and/or a negative voltage on the charge storage element. A switch within the solar monitor is coupled in a shunt configuration with the designated solar device and with a subsequent device in the array. The switch selectively couples the charge storage element to the designated solar device to vary an operating current that flows between the designated solar device and the subsequent solar device. The solar monitor includes a current detector to measure the current of the designated solar device, and a voltage detector to measure the voltage of the designated solar device.

1 . A solar monitor, comprising:
 a switch having a first contact coupled to a first port of a designated solar device within an array of operating solar devices that are coupled in series, wherein the switch is in a shunt configuration with the designated solar device and a subsequent solar device in the array of operating solar devices that are coupled in series, the switch varying an operating current flowing between the designated solar device and the subsequent solar device;   a charge storage element having a first terminal coupled to a second contact of the switch and having a second terminal coupled to a second port of the designated solar device;   a charger coupled to the first terminal of the charge storage element;   a voltage detector coupled to a node located between the first terminal of the charge storage element and the first port of the designated solar device; and   a current detector configured to measure a current at the first port of the designated solar device.   
     
     
         2 . The solar monitor of  claim 1  wherein the switch is coupled to the first port of the designated solar device through a fuse. 
     
     
         3 . The solar monitor of  claim 1  wherein the charger establishes a voltage on the charge storage device when the switch is open. 
     
     
         4 . The solar monitor of  claim 1  wherein the switch is open while the charger provides a negative charge to the first terminal of the charge storage element, wherein the switch is closed while the voltage detector measures a voltage at the node and while the current detector measures the current at the first port of the designated solar device, and wherein varying the operating current flowing between the designated solar device and the subsequent solar device includes decreasing the operating current in response to the negative charge when the switch is closed. 
     
     
         5 . The solar monitor of  claim 1  wherein the switch is open while the charger provides a positive charge to the first terminal of the charge storage element, wherein the switch is closed while the voltage detector measures a voltage at the node and while the current detector measures the current at the first port of the designated solar device, and wherein varying the operating current flowing between the designated solar device and the subsequent solar device includes increasing the operating current in response to the positive charge when the switch is closed. 
     
     
         6 . The solar monitor of  claim 4  wherein the switch is open while the charger provides a positive charge to the first terminal of the charge storage element, wherein the switch is closed while the voltage detector measures a voltage at the node and while the current detector measures the current at the first port of the designated solar device, and wherein varying the operating current flowing between the designated solar device and the subsequent solar device includes increasing the operating current in response to the positive charge when the switch is closed. 
     
     
         7 . The solar monitor of  claim 5  wherein the positive charge establishes a corresponding positive voltage on the charge storage element that exceeds an open circuit voltage of the designated solar device. 
     
     
         8 . The solar monitor of  claim 1  wherein the current detector includes a resistive element interposed between the first port of the designated solar device and the subsequent solar device, a first voltage detector coupled to a first terminal of the resistive element, and a second voltage detector coupled to a second terminal of the resistive element. 
     
     
         9 . The solar monitor of  claim 8  wherein the resistive element is established by a designated length of a conductor that couples to the first port of the designated solar device. 
     
     
         10 . The solar monitor of  claim 1  wherein the current detector is in a shunt configuration with the first port of the designated solar device and the subsequent solar device in the array of operating solar devices that are coupled in series. 
     
     
         11 . The solar monitor of  claim 1  wherein the current detector is in a series configuration with the first port of the designated solar device and the subsequent solar device in the array of operating solar devices that are coupled in series.