In order to coordinate automatic voltage control(AVC)systems of a large interconnected system,a multi-level multi-area hybrid automatic voltage control(MLMA-HAVC)system was constructed.This system began its trial operation in the Northeast China Grid in January 2010,and for the first time in China and abroad it realized automatic close-loop control of multi-area and multi-level interconnected power grid and multi-objective self-approaching optimization in aspects of security,high quality and economic operation.This system has three breakthroughs in theory and engineering application:1)Established the MLMA-HAVC theory to solve multi-objective optimization of large-scale system;2)proposed reactive power/voltage coordination control method to inhibit or further eliminate regional oscillations;3)presented advanced state estimation algorithm to guarantee acquisition of high reliability data.This paper summarizes the basic principle of MLMA-HAVC,and reports engineering realization of MLMA-HAVC system in the Northeast China Grid.
