Small-Signal Modeling and Experimental Validation of the Three-phase Quasi-Z-Source Inverter

In renewable energy applications, impedance source (Z-source) converters are increasingly used as an attractive alternative to classical two-stage converters. The main advantage of Z-source converters is the possibility to achieve a single-stage DC-AC conversion with both buck and boost operations. In terms of control, the design is challenging due to the system high order. In this paper, different closed loop control schemes are implemented for the quasi-Z-Source three-phase Inverter (qZSI). The detailed small-signal model is obtained in order to tune the control system. Along with the classical Proportional-Integral (PI) regulators, a Proportional-Resonant (PR) regulator is implemented in order to improve the control system performances. To validate the controller design, both simulations and experimental results are provided.