Phased preventive control of smart distribution system under non-fault conditions

Online security early warning and preventive control are important parts of self-healing for smart distribution system. The structure of security early warning and preventive control are presented in this paper. Preventive control is equivalent to a multi-stages decision problem, which is divided into three stages: regulation of output for distributed generators and reactive power compensation device, network reconfiguration of exchanging the status between sectionalizing switches and tie switches, and load shedding. Whether the stage is executed or not based on the value of state function. Order of distributed generators and capacitor rank are determined by the value of sensitivity about injecting reactive power nodes with the over limit of voltage amplitude node, basic-loop matrix is presented to avoid infeasible solutions which do not satisfy topological constraints in the network reconfiguration. The effectiveness of the propose approach is demonstrated by simulations on IEEE 33-nodes system.