Three-phase switch-mode rectifier constructed using single-phase modules

A three-phase (3φ) switch-mode rectifier (SMR) constructed using single-phase (1φ) modules is presented in this paper. The AC sides of three modules are Δ-connected, with proper control, good power quality in line drawn currents under well-regulated DC output voltage is obtained. As one module fault occurs, the proposed 3φ SMR becomes V-connected. At the worst case, when two constituted 1φ modules are faulted, the proposed 3φ SMR will be operated as 1φ SMR to continuously supply regulated DC voltage output. As to the control aspect, the dynamic model of the 3φ SMR under nominal operating condition is estimated. And accordingly, a feedback controller is designed to meet the given voltage regulation control specifications. Then a robust controller is further developed to reduce the control performance degradation due to the changes of operating condition and number of connected modules.