TITLE:
Research of Mining STATCOM Based on Hybrid Multilevel H-bridge Inverter
AUTHORS:
Yaopu Li, Cong Wang, Xu Zhao, Kai Zhang
KEYWORDS:
H-bridge; STATCOM; SVG; Hybrid; Coal Mine; PWM Control; Inverter
JOURNAL NAME:
Energy and Power Engineering,
Vol.5 No.4B,
October
30,
2013
ABSTRACT: The paper presents a new STATCOM system based on
H-bridge inverter. It can be used in mine power network. It has been commonly
verified for the positive effects of SVG on the reactive power compensation and
voltage fluctuation suppression. This paper focuses on a generalized structure
of multilevel power converter where individual voltage sources are not
necessarily the same. The cascade H-bridge consists of two cells, high-voltage
cell and low-voltage cell. The high-voltage cell is responsible for voltage
lifting, while the low-voltage cell is responsible for PWM modulation. If two
cells are cascaded with DC voltages in a ratio of 2:1, the single-phase output
voltage can reach 7 levels. Increasing voltage levels of output waveform can
bring up AC current quality, optimize harmonic spectrum and enhance converter
efficiency. The hybrid multilevel is characterized by per-phase series
connection of a high-voltage H-bridge converter and a low-voltage H-bridge
converter. Due to the different capacitor voltage, it is a key problem as to
how to maintain the capacitor’s voltage at a reference level. Independent DC
source can effectively ensure the DC voltage. Through the reactive power
compensation technology, the three-phase voltage and current can remain at the
same phase.