Switching coordination of distributed dc-dc converters for highly efficient photovoltaic power plants

摘要

A distributed photovoltaic (PV) power plant includes a plurality of distributed dc-dc converters. The dc-dc converters are configured to switch in coordination with one another such that at least one dc-dc converter transfers power to a common dc-bus based upon the total system power available from one or more corresponding strings of PV modules. Due to the coordinated switching of the dc-dc converters, each dc-dc converter transferring power to the common dc-bus continues to operate within its optimal efficiency range as well as to optimize the maximum power point tracking in order to increase the energy yield of the PV power plant.

主权项

1. A string level maximum power point distributed photovoltaic (PV) power plant comprising:
one or more dc-dc converters; at least one string of PV modules, wherein each dc-dc converter receives power from at least one corresponding string of PV modules, and further wherein at least one dc-dc converter is configured to transfer power to a common dc-bus based upon the total system power available from each of its corresponding strings of PV modules such that each dc-dc converter transferring power to the common dc-bus continues to operate within its optimal efficiency range to increase the energy yield of the PV power plant; and at least one combiner box, each combiner box comprising:
at least one local control unit, wherein each local control unit is configured to control a single dc-dc converter selected from the one or more dc-dc converters based on commands received via an external communication bus; anda local data bus configured to provide communication between local control units, wherein each local control unit is configured to select and control operation of its corresponding dc-dc converter such that at least one dc-dc converter transfers power to a common dc-bus based upon the total system power available from each of its corresponding strings of PV modules, and further such that each dc-dc converter transferring power to the common dc-bus continues to operate within its optimal efficiency range to increase the energy yield of the PV power plant.