With the development of IGBT and GTO, more and more high-voltage and high-power devices applied in the power system.In terms of stability, harmonic, response speed,the superiority of STATCOM is more far than SVC.In order to make STATCOM play better results,the key is in controller design level.Through the introduction of advanced intelligent control method-extension control,extension control doesn't require to establish accurate mathematical model and has better control performance for the nonlinear system.In addi…