Hierarchical control of power distribution systems

The concepts of hierarchical system theory, in conjunction with power system engineering, have been applied to enable the real-time control of a large-scale power distribution system.1 The control objective of the distribution system consists of security (equipments protection) and operation (continuity of service) requirements to be satisfied within the feasible control boundaries for all substations composing the distribution system. The overall control strategy for each substation is decomposed into independent control functions which are ordered (ranked) to meet a hierarchy of control requirements specified by the system´s physical operation. This approach was adopted not only to simplify the real-time control problem solution, but also was necessitated by the requirement that a partial feasible solution be provided which meets higher priority objectives when a total feasible solution does not exist. This paper describes, in the hierarchical framework, the physical process, the network decomposition and modeling, the control decomposition and criteria, and the control procedure along with numerical results.