Title :
Hysteresis-band control based PWM strategy of three-level neutral-point balance
Author :
Wenxi, Yao ; Zhengyu, Lu ; Rongxiang, Zhao ; Wanmin, Fei ; Zhaoming, Qiao
Author_Institution :
Nat. Lab. of Power Electron., Zhejiang Univ., Hangzhou, China
Abstract :
A new method of neutral-point balance based on hysteresis-band control for NPC three-level inverters is proposed in this paper. The neutral-point is balanced by PWM control according to the direction of neutral-point current and the state of neutral-point voltage. The neutral-point current direction is got by output current of each phase and PWM group. The state of neutral point voltage is decided by hysteresis-band control. PWM group is regrouped when it goes against the neutral point potential balance. Being independent of PWM mode, this scheme can be used in any PWM mode for neutral-point balance control. The amplitude of neutral point voltage ripple and the switch times of IGBT can be adjusted by regulating the width of hysteresis-band. The method is verified by simulation and experiment of three-level converter with SHEPWM control scheme.
Keywords :
PWM invertors; insulated gate bipolar transistors; switching convertors; IGBT; NPC three-level inverters; PWM control; PWM strategy; hysteresis-band control; neutral-point current; three-level converter; three-level neutral-point balance; Energy conversion; Hysteresis; Insulated gate bipolar transistors; Laboratories; Power electronics; Pulse width modulation; Pulse width modulation inverters; Space vector pulse width modulation; Switches; Voltage control;
Conference_Titel :
Applied Power Electronics Conference and Exposition, 2005. APEC 2005. Twentieth Annual IEEE
Print_ISBN :
0-7803-8975-1
DOI :
10.1109/APEC.2005.1452966
