Gradient based centralized optimal Volt/Var control strategy for smart distribution system

With the development of enabling power electronic devices, such as the solid state transformer (SST) [1], the concept of a novel future renewable electric energy delivery and management system [2] is raised. The Future Renewable Electric Energy Delivery and Management (FREEDM) system is a smart distribution system that can accommodate distributed renewable energy, distributed energy storage devices, and plug-in hybrid electric vehicles (PHEVs), As the complexity of the power system increases, the need for a sophisticated power system operation and control method is becoming a critical issue. The new devices shouldn´t disturb normal system operations, and the capabilities of these devices should help support the customer needs and enhance system performance. Therefore, this paper develops a centralized Volt/Var control strategy to minimize power system losses while maintaining voltage profiles within acceptable limits.