| Title |
An Improved Voltage Control Scheme for DC-Link Voltage Balancing in a Four-Level Inverter |
| Authors |
김래영(Kim, Rae-Yeong) ; 이요한(Lee, Yo-Han) ; 최창호(Choe, Chang-Ho) ; 현동석(Hyeon, Dong-Seok) |
| Keywords |
DC-link Balancing ; Multi-level Inverter ; SVPWM ; Variable Speed Drives |
| Abstract |
Multi-level inverters are now receiving widespread interest form the industrial drives for high power variable speed applications. Especially, for the high power variable speed applications, a diode clamped multi-level inverter has been widely used. However, it has the inherent problem that the voltage of the link capacitors fluctuates. This paper describes a voltage control scheme effectively to suppress the DC-link potential fluctuation for a diode clamped four-level inverter. The current to flow from/into the each link capacitor is analyzed and the operation limit is obtained when a conventional SVPWM is used. To overcome the operation limit, a modified carrier-based SVPWM is proposed. Various simulation and experiment results are presented to verify the proposed voltage control scheme for DC-link voltage balancing. |