Design and Analysis of Novel Tristate Quasi-Z-Source Converter with Improved Dynamic Performance

In this article, a novel fifth order two switch tristate quasi-Z-source boost converter (TQZBC) topology is proposed. It features a two-switch structure, a shared ground between load and source, low voltage stress and achieves high voltage gains corresponding to conventional DC-DC quasi-Z-source converters. With tristate configuration peak inductor current is reduced by incorporating a freewheeling interval through an simple switching control technique at the end of inductor charging state. Detailed examination involving steady-state and small-signal models is formulated for TQZBC and compared with those conventional boost converters, investigating various performance aspects. Simulations confirm the controller's performance in achieving regulation objectives. All theoretical findings are verified experimentally using TMS320F28379D DSP board for converter switching implementation and 240 W, 48 V to 120 V TQZBC prototype is developed.