Seamless control of distributed multi-converter system with high power quality

Robust control of inverter-interfaced distributed energy resource (DER) in a smart distribution grid is essential in order to facilitate flexibility of the grid. This paper presents a control structure for multi-converter system based on direct-current control and dynamic power sharing at the point of common coupling (PCC). The system includes two voltage source converters (VSCs) for grid interface of DERs and the active damping controller in the voltage control which is provided by the converter-interfaced load (CIL) for effective rejection of disturbances. On the other hand, wide band voltage control loop in both grid-connected and islanded modes is designed to improve the dynamic response of the system featuring power quality (PQ) improvement. The proposed scheme addresses a robust controller against interaction dynamics between active damping and current tracking controller in the presence of grid induced disturbances.