Experimental and Theoretical Analysis of Trans-Z-Source Inverters With Leakage Inductance Effects

Transformer-based Z-source (trans-Z-source) inverters are recently proposed to extend the traditional Z-source inverter with higher buck-boost capabilities as well as reducing the passive components at the same time. A new scheme for high-boost trans-Z-source inverter is proposed in this paper. In the traditional trans-Z-source inverters for high boosting voltages, the modulation index can be high by increasing the transformer turns ratio. The proposed topology has two transformers, two capacitors, and three diodes in the Z-impedance network. With fewer active and passive components and low shoot-through duty ratio, the new topology produces an output voltage with high quality and low total harmonic distortion. The new method is compared with the previously proposed schemes in terms of voltage stresses on diodes and capacitors, efficiency, voltage gain, and switching device power factor of the diodes. The operating principles of the new scheme along with the transformer leakage inductance effects on the voltage gain have been investigated through detailed analytical and mathematical derivations. The validity and effectiveness of the new circuit have been verified by experiments and simulations.