Design of a Hybrid Controller for the Three-phase Four-leg Voltage-source Inverter with Unbalanced Load

作者：Doan Van Tuan; Kim Ki Young; Choi Woojin^*; Kim Dae Wook

来源：Journal of Power Electronics, 2017, 17(1): 181-189.

DOI：10.6113/JPE.2017.17.1.181

• Hybrid controller
• Resonant controller
• Three-phase four-leg voltage-source inverter
• Unbalanced load condition

The three-phase four-leg voltage-source inverter topology is an interesting option for the three-phase four-wire system. With an additional leg, this topology can achieve superior performance under unbalanced and nonlinear load conditions. However, because of the low bandwidth of conventional controllers in high-power inverter applications, the system cannot guarantee a balanced output voltage under the unbalanced load condition. Most of the methods proposed to solve this problem mainly use the multiple synchronous frame method, which requires several controllers and a large amount of computation because of frame transformation. This study proposes a simple hybrid controller that combines proportional integral (PI) and resonant controllers in the synchronous frame synchronized with the positive-sequence component of the output voltage of the three-phase four-leg inverter. The design procedure for the controller and the theoretical analysis are presented. The performance of the proposed method is verified by the experimental results and compared with that of the conventional PI controller.

• 出版日期2017-1