Title :
A Novel Balancing Method for DC Voltage of Cascaded Multilevel STATCOM
Author :
Sun, Yao ; Ma, Luyao ; Xiong, Liansong
Author_Institution :
Sch. of Electr. Eng., Xi´´an Jiaotong Univ., Xi´´an, China
Abstract :
The stability of DC voltage is crucial to cascaded multilevel converter-based STATCOM. This paper introduces a hierarchical control scheme for DC voltage of cascaded STATCOM. The first layer of the control scheme maintains the phase voltage and the second layer balance the capacitor voltage within each phase. Specially, for the second layer we propose a novel method incorporating an extra balancing capacitor to redistribute energy among inverter modules. We develop two control strategies for the balancing process. Two-module five-level STATCOM was simulated as an example and results indicate that the proposed control scheme effectively stabilized the DC voltage. Finally, the two balancing strategies are theoretically compared.
Keywords :
power system stability; static VAr compensators; voltage control; DC voltage control scheme; DC voltage stability; balancing method; capacitor voltage; cascaded multilevel STATCOM; cascaded multilevel converter-based STATCOM; extra balancing capacitor; inverter modules; phase voltage; second layer balance; Automatic voltage control; Capacitors; Inverters; Silicon; Switches;
Conference_Titel :
Power and Energy Engineering Conference (APPEEC), 2012 Asia-Pacific
Conference_Location :
Shanghai
Print_ISBN :
978-1-4577-0545-8
DOI :
10.1109/APPEEC.2012.6307310