A Novel Cooperative Protocol for Distributed Voltage Control in Active Distribution Systems

In this paper, a novel cooperative protocol has been proposed to provide a proper voltage control for multiple feeders having a transformer tap-changer (LTC), unbalanced load diversity (station with different feeder loads) and multiple distributed generation (DG) units in each feeder. The proposed cooperative protocol has been defined according to the distributed control technology, where LTC and DG units are considered as control agents. Two conflicting objectives have been defined for each control agent. The first objective aims to achieve the system requirements by minimizing the voltage deviation and the second objective aims to achieve the device requirements by reducing the tap operation and maximizing the energy capture for LTC and DG units, respectively. The interior structures of the control agents and the communication acts between them have been designed to achieve the best compromise between the two objectives of each control agent. The effectiveness of the proposed cooperative scheme has been verified via different case studies.