Compensation of Wide Range and Low Dc-link Voltage with Hybrid-statcom

A hybrid-STATCOM in three-phase power system is proposed and discussed as a costeffective reactive power compensator for medium voltage level application is proposed in this paper. Because of these prominent characteristics, the system costs can be greatly reduced. Its V-I characteristic is then analyzed, discussed, and compared with traditional STATCOM and capacitive-coupled STATCOM (C-STATCOM). The system parameter design is then proposed on the basis of consideration of the reactive power compensation range and avoidance of the potential resonance problem. After that, a control strategy for hybrid-STATCOM is proposed to allow operation under different voltage and current conditions, such as unbalanced current, voltage dip, and voltage fault. By using the simulation results we can verify the wide compensation range and low DC-link voltage characteristics and the good dynamic performance of the proposed hybrid-STATCOM.