In this paper

the main circuit topology structure of cascade multi-level STATCOM and the phase shifting modulation principle of unipolar double frequency carrier are studied. The STACOM control system is designed. In Matlab / Simulink software

6 kV cascade 8 H-bridge converters STATCOM is set up. It is shown by the simulation that STATCOM can track load fluctuations fast so to achieve dynamic reactive power compensation. The developed ±2.8 Mvar

6 kV cascade STATCOM device is put into operation at 6 kV substation at Jiangzhuang Mine of Shandong Energy Zaozhuang Mining Group Co.

Ltd. It passes actual test and also proves that the STATCOM has superior reactive power compensation function.