A New Simplified Space–Vector PWM Method for Three-Level Inverters.pdf

IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 16, NO. 4, JULY 2001 545 A New Simplified Space–Vector PWM Method for Three-Level Inverters Jae Hyeong Seo, Member, IEEE, Chang Ho Choi, Member, IEEE, and Dong Seok Hyun, Senior Member, IEEE Abstract—In this paper, a new simplified space–vector pulse width modulation (SVPWM) method for three-level inverter is proposed. This method is based on the simplification of the space–vector diagram of a three-level inverter into that of a two-level inverter. If simplified by the proposed method, all the remaining procedures necessary for the three-level SVPWM are done like conventional two-level inverter and the execution time is greatly reduced. The dc-link neutral-point potential control al- gorithms are implemented more easily. And the proposed method can be applied to the multi-level inverters above three-level. The validity of the new SVPWM method is verified by experiment with a 1000 KVA three-level insulated gate bipolar transistor (IGBT) inverter. Index Terms—Multilevel inverter, space-vector PWM, three- level inverter. I. INTRODUCTION Fig. 1. Circuit diagram of a three-level inverter. ECENTLY, with the dramatic improvements in high Rvoltage technologies, high voltage insulated gate bipolar switching frequency and the blocking voltage of the switching transistor (HVIGBT) and gate commutated thyristor (GCT) are device is half of the dc-link voltage. So the three-level inverter expanding the area of their application. For the high perfor- topology is generally used in realizing the high performance, mance ac drive systems at increased power level, high q