Multi-input PV inverter system and method

A method for determining a mode of operation of a power generation system that is coupled to a power grid irrespective of a state of operation of said power grid, the method comprising:

• a) determining a voltage at a point of common coupling, said point of common coupling being a coupling point to which said power grid and said power generation system and at least one load is coupled;
• b) determining a rise in said voltage determined in step a);
• c) determining a rise in current output from an inverter of said power generation system;
• d) determining if a specific condition is true, said specific condition being
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• e) determining that said power generation system is operating in an on-grid operating mode if said specific condition is false;
• f) determining that said power generation is operating in an off-grid operating mode if said specific condition is true;
• wherein
• Rg is a typical resistance between the grid and said inverter;
• VT0 is a terminal voltage when said inverter is not turned on;
• VT is a voltage measured at said terminals of the battery inverter;
• IPV is a current supplied by said inverter to said load;
• and
• wherein steps a)-c) are repeated for multiple readings of said currents and voltages.

A system for managing an operation of a power inverter for use with a power generation subsystem, the system comprising:

• a data sensing module for receiving power related data from circuitry monitored by said system;
• a data processing module for calculating mode of operation data based on said power related data received by said data sensing module, said mode of operation data being used to determine a mode of operation for said power inverter;
• a controller module for controlling said power inverter based on said mode of operation determined by said data processing module;
• wherein
• said mode of operation data is based on an amount of voltage sensed at a point of common coupling between said power grid, said battery inverter, and said power inverter irrespective of a state of operation of said power grid.