Hierarchical and Distributed Control of Voltage/VAR

Recent developments in the restructuring of power systems, and the emerging of distributed and renewable generation, show voltage/VAR optimization and control of a large-scale power system to be an important issue. With so many independent entities appearing in a restructured power system, traditional centralized optimization and control approaches cannot easily meet the various strict requirements for online voltage/VAR optimization and control. The rapid development of computer network technology and the application of high-speed, broadband telecommunication techniques have provided new opportunities for power system voltage/VAR optimization and control. The economical and reliable merits of voltage/VAR optimization and control scheme as proposed in this chapter indicate that distributed and hierarchical generation will be the trend for large-scale power system voltage/VAR optimization and control.