Abstract: A control system and method include a control strategy and a UDE (Uncertainty and Disturbance Estimator)-based controller incorporated into the control strategy to achieve proportional load sharing for parallel-operated inverters. The UDE-based controller regulates the reactive power against the output generated by a reactive power reference unit according to the load voltage to generate the amplitude of the control voltage. The conventional droop method regulates real power to generate the phase of the control voltage. As a result, the model uncertainties (e.g., parameter drifts and uncertain output impedance), and system disturbances (e.g., fluctuating DC-link voltage and load change) can be estimated and compensated for accurate load sharing.

Abstract: A control system and method include a control strategy and a UDE (Uncertainty and Disturbance Estimator)-based controller incorporated into the control strategy to achieve proportional load sharing for parallel-operated inverters. The UDE-based controller regulates the reactive power against the output generated by a reactive power reference unit according to the load voltage to generate the amplitude of the control voltage. The conventional droop method regulates real power to generate the phase of the control voltage. As a result, the model uncertainties (e.g., parameter drifts and uncertain output impedance), and system disturbances (e.g., fluctuating DC-link voltage and load change) can be estimated and compensated for accurate load sharing.

Abstract: A method of controlling an inverter, by modelling a synchronous generator is provided.

Abstract: The invention is concerned with a device and a method for controlling an inverter associated with a power source, which typically will be a distributed power source. The role of an inverter is to modulate the electrical power output, e.g. to provide a three phase AC electrical output at suitable voltage, where the output is to be supplied to a conventional power distribution, grid. The invention involves modelling the behaviour of a synchronous electrical generator. Variables represent the angular position and rotational speed of the virtual rotor (14) of this virtual synchronous generator. The torque electromagnetically exerted on the rotor is calculated from a measured inverter output current, and from a variable representing excitation current in the rotor.