Controlling Method of Cascaded H-bridge Multilevel Inverter based on CPS-SPWM Technique
You Linxu1, Wang Ruifeng2, Guo Moufa1
1. College of Electrical Engineering and Automation, Fuzhou University, Fuzhou 350116; 2. State Grid Fujian Technical Training Center, Quanzhou, Fujian 362000
Abstract：Cascaded H-bridge multilevel inverter is appropriate for varies occasions of high voltage and large current. Carrier Phase Shifted Sinuous Pulse Width Modulation (CPS-SPWM) technique is apt to realize, which has high equivalent carrier frequency, has been the most widely used modulation technique on cascaded multilevel inverter. In this paper, an improved method of carrier phase shift modulation method is adopted which needs less hardware resources. On the basis of detailed analysis on its modulation principle, a simulation model of cascaded H-bridge multilevel inverter is built using PSCAD/EMTDC software. Combining a physical experimental system based on IPM modules, the influence of carrier frequencies is studied on the harmonic characteristic of inverter output voltage. The simulation results and experiment results both show that improved CPS-SPWM technique can make the output voltage of inverter approach to sinusoidal wave better and reduce its distortion factor.
2016, Vol. 17 
