| Popis: |
This paper presents a reduced DC voltage-fed transformer-less D-STATCOM with improved configurations embedding Z-source element at the AC side. The additional Z-source element helps to achieve additional boost factor and the same has been derived from conventional Z-source derived DCDC converters. In the proposed configuration, no shoot through state is required and DC bus voltage of the converter does not have any zero state. The bidirectional switches added in the Z-source converter conducts only during the free-wheeling period of the converter operation and hence associated power losses are minimal in these bidirectional switches. A simple configuration based on inductor-capacitor-diode and an advanced coupled inductor based configurations are proposed. The various modes of operation, closed loop control in STATCOM mode, the leakage current-path analysis and its detailed performance evaluation are presented. The proposed configuration requires nearly (1/4) times the DC bus voltage (PV stack voltage) compared to standard single stage direct PV fed converters like HERIC, H5 etc. Simulation results are presented to validate the effectiveness of the proposal. |
