Dynamic voltage restorer using a multilevel converter with a novel cell structure

Voltage sags and swells have a severe impact on sensitive loads. To overcome this problem Dynamic Voltage Restores (DVR) are often used. The DVR is very attractive due to its potential for fast dynamic response to sags disturbances. In this paper, a new multilevel power converter structure for the DVR is proposed. This structure uses three single phase inverters and one three-phase inverter. In this way, a power converter with a five level output voltage is obtained. To control the proposed multilevel power converter a sliding mode controller is used. This control system presents important characteristics such as fast dynamic response and robustness to external perturbations. Several computer simulation results are presented in order to verify the proposed DVR structure.