Title |
Voltage Balancing Control of Input Voltage Source Employing Series-connected Capacitors in 7-level PWM Inverter |
Authors |
김진산(Jin-San Kim) ; 강필순(Feel-soon Kang) |
DOI |
http://doi.org/10.5370/KIEE.2018.67.2.209 |
Keywords |
Multilevel inverter ; Voltage imbalance ; Capacitor |
Abstract |
This paper present a 7-level PWM inverter adopting voltage balancing control to series-connected input capacitors. The prior proposed 7-level PWM inverter consists of dc input source, three series-connected capacitors, two bidirectional switch modules, and an H-bridge. This circuit topology is useful to increase the number of output voltage levels, however it fails to generate 7-level in output voltage without consideration for voltage balancing among series-connected capacitors. Capacitor voltage imbalance is caused on the different period between charging and discharging of capacitor. To solve this problem, we uses the amplitude modulation of carrier wave, which is used to produce the center output voltage level. To verify the validity of the proposed control method, we carried out computer-aided simulation and experiments using a prototype. |