UDE-based robust droop control for parallel inverter operation

A method for controlling an inverter, said method comprising:

• measuring a load voltage and a current associated with said inverter utilizing a plurality of sensors that measure said load voltage and said current associated with said inverter;
• calculating a real power and a reactive power of said inverter with a power unit;
• calculating an RMS load voltage with an RMS component;
• generating a reactive power reference from a feedback load voltage passed from said RMS component;
• filtering a high-frequency component from said reactive power with a low-pass filter;
• controlling said reactive power and providing a voltage set-point associated with an amplitude of a control voltage with a UDE (Uncertainty and Disturbance Estimator)-based controller, wherein said UDE-based controller comprises a configuration of error dynamics, a UDE (Uncertainty and Disturbance Estimator) filter, and a control configuration;
• filtering another high-frequency component from said real power utilizing another low-pass filter;
• generating a phase of said control voltage utilizing a droop coefficient component, a summation component, and an integral component;
• and
• generating said control voltage according to said amplitude and said phase of said control voltage utilizing a control output component.