标题：Neutral-Point Voltage Balancing Control for Three-Level T-Type Inverter Using SHEPWM
作者：Zhang, Tongsheng; Du, Chunshui; Qin, Changwei; Xing, Xiangyang; Chen, Alian; Zhang, Chenghui
作者机构：[Zhang, Tongsheng; Du, Chunshui; Qin, Changwei; Xing, Xiangyang; Chen, Alian; Zhang, Chenghui] Shandong Univ, Sch Control Sci & Engn, Jinan, Peoples R 更多
会议名称：8th IEEE International Power Electronics and Motion Control Conference (IPEMC-ECCE Asia)
会议日期：MAY 22-26, 2016
来源：2016 IEEE 8TH INTERNATIONAL POWER ELECTRONICS AND MOTION CONTROL CONFERENCE (IPEMC-ECCE ASIA)
关键词：selective harmonic elimination pulse-width modulation (SHEPWM);; eliminate low order harmonics; neutral-point voltage balancing;; three-level T-type inverter
摘要：Selective harmonic elimination pulse-width modulation (SHEPWM) is a well-known switching technique applied in power electronics field for eliminating low order harmonics. According to symmetrical pulse patterns over the quarter of the period in SHEPWM, the neutral-point voltage could be balance naturally in a certain range. However, the neutral-point voltage fluctuation would be enlarging as the output current increases. In addition, when neutral-point voltage is unbalanced seriously, it would cost much time to recover balance on the classical SHEPWM modulation. Therefore, a novel neutral-point voltage balancing control method for three-level T-type inverter (3LT(2)I) using SHEPWM is presented, which installs a cascade small-vector control system behind the conventional three-phase SHEPWM modulation. In order to reduce the switching losses, the small-vector control system unit can be disabled or enabled according to deviation level of the neutral-point voltage. Moreover, the novel control method does not affect the output line-to-line voltage waveforms of SHEPWM inverter. Therefore, it not only has the same effect with the conventional SHEPWM on eliminating low order harmonics, but also can minimize the fluctuation of the neutral-point voltage and restore the neutral-point voltage balance rapidly compared with the conventional SHEPWM. Simulation and experimental results confirmed the performance and effectiveness of the proposed method.