Photovoltaic Systems with Abnormality Detection Architecture

Abstract

One aspect of the inventive technology disclosed herein, in certain embodiments, may involve the determination of at least one measured, instantaneous intra-string current difference for each of the power generating string, and the use of such determinations to assess the existence of leakage current, a frequent ground fault predecessor, thereby enabling preclusion of a ground fault that would otherwise result. Certain methods and detection architecture may enable precise abnormality location, e.g., enabling the identification of which solar module assembly in particular is faulty. Another aspect relates generally, in certain embodiments, to detection circuit architecture operable to sequentially impress a leakage current inducing voltage upon each rail of a photovoltaic system. Another relates generally, in certain embodiments, to the use of at least one current interrupter at each end of a string to preclude flow therethrough in the event of, e.g., unintended field reversal.

What is claimed is: 
     
         1 - 62 . (canceled) 
     
     
         63 . A solar power circuit operable to detect operational abnormality, said circuit comprising:
 a solar power array that itself comprises at least one power generating string, said at least one power generating string comprising a plurality of serially connected solar module assemblies;   at least one measured, instantaneous intra-string current difference determinator for each of said power generating string, each said determinator determining an instantaneous difference in string current between a respective two points on said at least one power generating string;   operational abnormality assessment componentry that acts on data generated by said at least one measured, instantaneous intra-string current difference determinator; and   computerized detected leakage response componentry that is responsive to said operational abnormality assessment componentry.   
     
     
         64 . A solar power circuit operable to detect operational abnormality as described in  claim 63  wherein said at least one measured, instantaneous intra-string current difference determinator comprises a differential current measurer. 
     
     
         65 . A solar power circuit operable to detect operational abnormality as described in  claim 63  wherein said at least one measured, instantaneous intra-string current difference determinator comprises two current measurers, one at a first of said respective two points and another at a second of said respective two points. 
     
     
         66 . A solar power circuit operable to detect operational abnormality as described in  claim 65  wherein said at least one measured, instantaneous intra-string current difference determinator comprises computerized componentry that compares a current measurement at said first point with a current measurement at said second point. 
     
     
         67 . A solar power circuit operable to detect operational abnormality as described in  claim 63  wherein said at least one solar power generating string comprises no converter. 
     
     
         68 . A solar power circuit operable to detect operational abnormality as described in  claim 63  wherein said at least one solar power generating string comprises only one converter. 
     
     
         69 . A solar power circuit operable to detect operational abnormality as described in  claim 63  wherein said at least one solar power generating string comprises more than one converter. 
     
     
         70 . A solar power circuit operable to detect operational abnormality as described in  claim 69  wherein said at least one solar power generating string comprises one converter per module. 
     
     
         71 . A solar power circuit operable to detect operational abnormality as described in  claim 70  further comprising measurement componentry configured to measure a converter input current, a converter output current, converter input voltage and converter output voltage of a converter of a serially connected module assembly that is nearest one rail of said at least one solar power generating string of said solar panel array. 
     
     
         72 . A solar power circuit operable to detect operational abnormality as described in  claim 63  wherein said at least one solar power generating string comprises no sub strings. 
     
     
         73 . A solar power circuit operable to detect operational abnormality as described in  claim 63  wherein said at least one solar power generating string comprises a plurality of substrings. 
     
     
         74 . A solar power circuit operable to detect operational abnormality as described in  claim 63  further comprising computerized data handling componentry configured to handle data generated by said at least one measured, instantaneous intra-string current difference determinator. 
     
     
         75 . An electrical circuit incorporated into a photovoltaic system having at least two rails, and enabling polarity reversal and detection of leakage current from said photovoltaic system, said electrical circuit comprising:
 rail disconnect switch componentry able to disconnect said at least two rails;   rail ground switch componentry able to independently ground each of said at least two rails;   at least one current limiting resistor established so leakage current will pass therethrough;   a ground connection with said at least one current limiting resistor; and   at least one current measurer established to detect said leakage current.   
     
     
         76 . An electrical circuit incorporated into a photovoltaic system having at least two rails, and enabling polarity reversal and detection of leakage current from said photovoltaic system as described in  claim 75  wherein said rail disconnect switch componentry comprises one rail disconnect switch for each of said at least two rails. 
     
     
         77 . An electrical circuit incorporated into a photovoltaic system having at least two rails, and enabling polarity reversal and detection of leakage current from said photovoltaic system as described in  claim 75  wherein said rail ground switch componentry comprises at least one rail ground switch. 
     
     
         78 . An electrical circuit incorporated into a photovoltaic system having at least two rails, and enabling polarity reversal and detection of leakage current from said photovoltaic system as described in  claim 77  wherein said rail ground switch componentry comprises one rail ground switch for each two of said at least two rails. 
     
     
         79 . An electrical circuit incorporated into a photovoltaic system having at least two rails, and enabling polarity reversal and detection of leakage current from said photovoltaic system as described in  claim 78  wherein said rail ground switch comprises a single pole, double throw switch. 
     
     
         80 . An electrical circuit incorporated into a photovoltaic system having at least two rails, and enabling polarity reversal and detection of leakage current from said photovoltaic system as described in  claim 75  wherein said rail ground switch componentry is operable to reverse polarity of module side componentry. 
     
     
         81 . An electrical circuit incorporated into a photovoltaic system having at least two rails, and enabling polarity reversal and detection of leakage current from said photovoltaic system as described in  claim 80  wherein said module side componentry comprises at least one solar power string. 
     
     
         82 . An electrical circuit incorporated into a photovoltaic system having at least two rails, and enabling polarity reversal and detection of leakage current from said photovoltaic system as described in  claim 80  wherein said module side componentry comprises at least one solar power array. 
     
     
         83 - 123 . (canceled)