Universal control unit for PV fed single stage inverters

A microgrid (MG) controller for a plurality of distributed generators (DGs) of Renewable Energy Sources (RESs), the MG controller comprising:

• a power sharing unit configured to share power proportionally in a single current controlled mode (CCM) between the plurality of DGs based on a power capacity for each DG of the plurality of DGs, the power sharing unit comprising:
• a robust current droop controller (RCDC) configured to provide proportional active current shared between the plurality of DGs;
• and
• a quasi-proportional resonant (QPR) regulator coupled to the RCDC within a unified architecture, the QPR regulator configured to regulate a reference current signal;
• and
• a DC-link voltage regulation unit comprising:
• a perturb and observe (P&O) Maximum solar Power Point Tracking (MPPT) control system configured to extract a maximum solar power point (MPP) for at least one photovoltaic (PV) array of PV arrays, wherein the P&O MPPT control system is further configured to extract the MPP based on an AC current measurement by a current sensor with a first power rating that is less than a second power rating for a PV inverter associated with the PV arrays;
• and
• a DC-link voltage controller configured to regulate, based on the MPP, an output voltage for at least one of the PV arrays using a current setpoint.

A method for controlling a microgrid of a plurality of distributed generators (DGs) of photovoltaic (PV) arrays, the method comprising:

• sharing power proportionally in a single current controlled mode (CCM) between the plurality of DGs based on a power capacity for each DG of the plurality of DGs, sharing the power proportionally comprises:
• regulating a reference current signal with a quasi-proportional resonant (QPR) regulator within a unified architecture with a robust current droop controller (RCDC);
• and
• providing, based on the reference current signal, a proportional active current shared between the plurality of DGs;
• extracting, using a perturb and observe (P&O) Maximum solar Power Point Tracking (MPPT) control system of a DC-link voltage regulation unit, a maximum solar power point (MPP) for at least one of the PV arrays based on an AC current measurement by a current sensor with a first power rating that is less than a second power rating for a PV inverter associated with the PV arrays;
• and
• regulating, based on the MPP, an output voltage for at least one of the PV arrays using a current setpoint.