Patent ID: 8618692

Claim:
A distributed power system comprising: a plurality of DC power sources, each DC power source with positive and negative poles; a plurality of power converters coupled respectively to the DC power sources, each power converter including a first terminal, a second terminal, a third terminal and a fourth terminal, wherein said first terminal is adapted for coupling to said positive pole and said second terminal is adapted for coupling to said negative pole; wherein each said power converter includes: (i) a control loop adapted for setting the voltage between or current through said first and second terminals, and (ii) a power conversion portion adapted to perform at least one of: converting power from said first and second terminals to said third and fourth terminals to discharge said power source connected thereto, or converting power from said third and fourth terminals to said first and second terminals to charge said power source connected thereto; wherein each of said power converters is adapted for serial connection to at least one other power converter by connecting respectively said third and fourth terminals, thereby forming a serial string; and a power controller adapted for coupling to said serial string, the power controller including a control part adapted to maintain current through or voltage across said serial string at a predetermined value.