Reverse Bias Protected Solar Array With Integrated Bypass Battery

Abstract

A method for protecting the photovoltaic cells in a photovoltaic (PV) way from reverse bias damage by utilizing a rechargeable battery for bypassing current from a shaded photovoltaic cell or group of cells, avoiding the need for a bypass diode. Further, the method mitigates the voltage degradation of a PV array caused by shaded cells.

1 . (canceled) 
     
     
         2 . A photovoltaic array with tolerance to damage from partial shading comprising:
 a plurality of modules connected in series for producing an electric current, each of the modules comprising at least one photovoltaic cell connected in parallel with at least one battery;   wherein during temporary shading from a light source of one or more, but not all, of the modules, the remainder of the modules remain lit by the light source to produce electric current; and   wherein, during temporary shading, the battery of the one or more shaded modules shunts the electric current within the respective module to protect the array from hot-spot damage.   
     
     
         3 . The photovoltaic array of  claim 2 , wherein the modules do not use any shunting diodes for protection. 
     
     
         4 . The photovoltaic array of  claim 2 , wherein the battery is integrated with the photovoltaic cell on a thin-film substrate. 
     
     
         5 . The photovoltaic array of  claim 2 , wherein the battery is a rechargeable battery. 
     
     
         6 . The photovoltaic array of  claim 2 , wherein the battery compensates for a voltage drop of the photovoltaic cell that is shaded while the photovoltaic array is generating power from light. 
     
     
         7 . The photovoltaic array of  claim 2 , wherein the at least one battery is sized for carrying a specified current without damage. 
     
     
         8 . The photovoltaic array of  claim 2 , wherein the at least one battery is sized with a storage capacity sufficient for providing energy during the period of temporary partial shading of the array, but not sufficiently large for providing energy during a substantial majority of an eclipse or nighttime period. 
     
     
         9 . The photovoltaic array of  claim 2 , wherein the array is mounted on a spacecraft placed in orbit around a body, and wherein the temporary shading is due to a part of the spacecraft at least partially blocking light from part of the array. 
     
     
         10 . The photovoltaic array of  claim 2 , wherein the photovoltaic cell and the battery are thin-film devices integrated on a common substrate. 
     
     
         11 . A photovoltaic array with tolerance to damage from partial shading comprising:
 a plurality of modules connected in series for producing an electric current, each of the modules comprising at least (N) photovoltaic cells connected in parallel with at least (M) batteries;   wherein during temporary shading from a light source of one or more, but not all, of the modules, the remainder of the modules remain lit by the light source to produce electric current; and   wherein, during temporary shading, the battery of the one or more shaded modules shunts the electric current within the respective module to protect the array from hot-spot damage.   
     
     
         12 . The photovoltaic array of  claim 11 , wherein the maximum power voltage from the (N) photovoltaic cells is substantially equal to the battery voltage from the (M) batteries. 
     
     
         13 . The photovoltaic array of  claim 12 , wherein (N) and (M) are natural numbers. 
     
     
         14 . The photovoltaic array of  claim 11 , wherein the modules do not use any shunting diodes for protection. 
     
     
         15 . The photovoltaic array of  claim 11 , wherein the battery is integrated with the photovoltaic cell on a thin-film substrate. 
     
     
         16 . The photovoltaic array of  claim 11 , wherein the battery is a rechargeable battery. 
     
     
         17 . The photovoltaic array of  claim 11 , wherein the battery compensates for a voltage drop of the photovoltaic cell that is shaded while the photovoltaic array is generating power from light. 
     
     
         18 . The photovoltaic array of  claim 11 , wherein the at least one battery is sized for carrying a specified current without damage. 
     
     
         19 . The photovoltaic array of  claim 11 , wherein the at least one battery is sized with a storage capacity sufficient for providing energy during the period of temporary partial shading of the array, but not sufficiently large for providing energy during a substantial majority of an eclipse or nighttime period. 
     
     
         20 . The photovoltaic array of  claim 11 , wherein the array is mounted on a spacecraft placed in orbit around a body, and wherein the temporary shading is due to a part of the spacecraft at least partially blocking light from part of the array. 
     
     
         21 . The photovoltaic array of  claim 11 , wherein the photovoltaic cell and the battery are thin-film devices integrated on a common substrate.