Design and Evaluation of a Bi-directional Data Acquisition and Control System for Small-scale Solar Power Plants

In a wide area power dispatch system, accurate and timely online communication between central supervisory control center and distributed energy resource (DER) power plants plays an important role for power operation stability. In order to collect online photovoltaics (PV) data from massive small-scale devices with different proprietary protocols, we first develop a 61850-based data aggregation server supporting commonly used protocols in data exchange. Furthermore, bi-directional Modbus controllers are then designed to transform dispatch commands from control center to RS-485 PV inverter commands. Combined with the 61850-based aggregation server and bidirectional Modbus controllers, our proposed PV information and communication technology (PV ICT) architecture is capable of dispatching PV power generation on massive non-61850-standard PV inverters.