Hybrid SVM-SOPWM Modulation of Current-Fed Three-level Inverter for High Power Application

Abstract

The goal of the paper is to develop a hybrid modulation technique to combine space vector modulation (SVM) scheme and synchronous optimal pulsewidth modulation (SOPWM) technique for current source inverter (CSI). SVM provides better dynamic performance, but is unable to produce less total harmonic distortion (THD) on inverter current at low device switching frequency (<; 1 kHz). SOPWM provides less THD even at low device switching frequency, however it needs a conversion technique to operate CSI and it needs an additional control technique to improve dynamic performance. Hence to overcome these limitations, this paper develops a single modulation technique called optimal SVM technique that can achieve less THD as well as better dynamic performance. To develop optimal SVM technique, three methods have been proposed in this paper. These three methods do not require an additional conversion technique to operate CSI and they provide less THD even under low device switching frequency of 450 Hz. Experimental results prove that the proposed modulation technique can provide better steady-state performance as well as dynamic performance.