Distributed power harvesting systems using DC power sources

A method comprising:

• connecting a plurality of photovoltaic sub strings in parallel across input terminals of a direct current power converter, wherein each photovoltaic sub string of the plurality of photovoltaic sub strings comprises a plurality of serially-connected photovoltaic cells;
• attaching a single bypass diode in parallel and in shunt across the input terminals;
• setting, by a controller and a control loop of the direct current power converter, a voltage or a current at the input terminals;
• and
• bypassing the plurality of photovoltaic sub-strings connected in parallel.

A system comprising:

• a plurality of photovoltaic panels connected in a series string, each comprising:
• a plurality of photovoltaic sub-strings connected in parallel, wherein each photovoltaic sub-string comprises a plurality of serially-connected photovoltaic-cells;
• a single diode connected in parallel and in shunt across the plurality of photovoltaic sub-strings connected in parallel and configured to bypass the plurality of photovoltaic sub-strings;
• and
• a direct current power converter comprising input terminals, output terminals, a control loop, and a controller, wherein:
• the input terminals are configured to receive input power from the plurality of photovoltaic sub-strings;
• the direct current power converter is configured to convert the input power to output power at the output terminals;
• the control loop is coupled to at least one of the input terminals;
• and
• the controller is configured to set, using the control loop, a voltage or a current at the input terminals;
• and
• an inverter comprising inverter input terminals, wherein the inverter is configured to receive power from the series string at the inverter input terminals.