Title :
A PWM strategy for four-leg voltage source converters and applications to a novel line interactive UPS in a three-phase four-wire system
Author :
Kim, Jang-Hwan ; Sul, Seung-Ki ; Kim, Hyosung ; Ji, Jun-Keun
Author_Institution :
Sch. of Electr. Eng. & Comput. Sci., Seoul Nat. Univ., South Korea
Abstract :
A four-leg pulse width modulation (PWM) voltage source converter (VSC) is used to supply three phase balanced voltage even under an unbalanced load condition in three phase four wire power distribution network. A novel carrier-based modulation technique for the converter is described with the concept of an offset voltage and also is extended to so called ´discontinuous PWM (DPWM)´ to minimize switching losses of VSC. As a practical application example of the four-leg VSC, a line interactive uninterruptible power supply (UPS) system is chosen. The feasibility of the proposed PWM strategies and control algorithms has been verified by the simulation and experimental results.
Keywords :
PWM power convertors; distribution networks; losses; power supply quality; switching convertors; uninterruptible power supplies; DPWM; PWM converter; UPS; VSC; carrier-based modulation technique; control algorithm; discontinuous PWM; four-leg pulse width modulation converter; offset voltage; power distribution network; switching losses; three phase balanced voltage; three phase four wire system; unbalanced load condition; uninterruptible power supply; voltage source converter; Phase modulation; Power conversion; Power systems; Pulse width modulation; Pulse width modulation converters; Switching converters; Switching loss; Uninterruptible power systems; Voltage; Wire;
Conference_Titel :
Industry Applications Conference, 2004. 39th IAS Annual Meeting. Conference Record of the 2004 IEEE
Print_ISBN :
0-7803-8486-5
DOI :
10.1109/IAS.2004.1348782
