Improving Power Quality and Distribution Efficiency in Micro-Grids by Cooperative Control of Switching Power Interfaces

Smart grids offer a wide application domain for power electronics. In fact, every distributed energy resource (DER) includes an electronic power processor (Switching Power Interface, SPI) which controls the currents drawn from the grid and can be driven to optimize the power flow, improve voltage stability and increase distribution efficiency. For these aims, such distributed SPIs must perform cooperatively. This is true also in low-voltage residential micro-grids, where the number of active DERs and the generated power may vary during daytime, thus requiring dynamic adaptation of SPI operation. To achieve this goal different approaches can be adopted, depending on the available communication capability. This paper discusses various control solutions applicable in absence of supervisory control, e.g., in residential micro-grids, where communication is possible between neighbor units only (surround control) or is not available at all (plug & play control).