Current-Controlled Interlinking Converter with Grid-Supporting Functionalities

A digital control system is proposed for grid-tied current-controlled interlinking converters that guarantees i) grid-supporting functionalities during grid connected operation and ii) automatic, prompt, and balanced power sharing among converters during islanded operation, without requiring mutual communication or supervising control. Thanks to the implementation of an underlying large-bandwidth inverter controller, several favorable features are conjointly achieved, including effective rejection of circulating harmonic currents, resiliency to grid parameters variations (e.g., frequency and magnitude), smooth transitions between grid-connected and islanded modes. All together, the obtained valuable features make the proposed controller a promising solution for the forthcoming microgrid and smart building scenarios.