Simulation Study of 21-level H-bridge Cascade STATCOM Modulation Techniques
Deng Suying1, Deng Mingfeng2
1. Fujian Shanghang Power Company, Shanghang, Fujian 364200; 2. School of Electrical and Information Engineering Changsha University of Science and Technology, Changsha 410004
Abstract：As the main structure of the STATCOM, H-bridge Cascade inverter modulation strategy is an important indicator to measure the performances of the STATCOM. In this paper, build the 21 level H-bridge cascade STATCOM main circuit and build the Carrier Phase-Shifted SPWM simulation module and carrier stacked SPWM simulation module. Analysis the simulation results of both modulation strategy. The simulation results show that Carrier Phase-Shifted SPWM simulation can balanced the power unit, however, the harmonic contents of the switching signal are large. When use carrier stacked SPWM simulation, the harmonics of STATCOM’s output voltage is lower than Carrier Phase-Shifted SPWM simulation. But the power units are unbalance and easy to damage the switching devices. Through the analysis of the advantages and disadvantages of the two modulations strategy, proposed a new carrier Phase-Shifted Stacked SPWM modulation strategy. The simulation results show that this new modulation strategy not only can balance the power units but also can reduce the harmonic contents of the switching signal. These features are better than Carrier Phase-Shifted SPWM simulation and Carrier-Stacked SPWM simulation strategy.
2014, Vol. 15 
