Abstract
Distributed generators (DGs) in Smart Grids should actively participate in the grid control of active power (P), reactive power (Q), frequency (f), and voltage (U) through their grid interfaces, namely inverters. As these DGs are joining the existing conventional power systems and for smooth transition towards Smart Grids, these DGs must follow the existing grid control, which is used by the UCTE. However, standard communication between utilities controllers and inverters is needed for the grid control and for the exchange of power. Therefore, a strategy is proposed depending on the UCTE grid control by clustering the secondary control using international communication standards. De facto, proprietary and standard protocols are investigated for this purpose. Then, logical nodes needed for primary and secondary grid control are adopted from the IEC 61850 that ensures interoperability. For communication, standard legacy SCADA protocols IEEE P1815 (DNP3) and IEC 60870-5-104 are proposed, which introduce standard communication mechanism.