Bode diagram based control system design of three phase grid tied photovoltaic systems with Quasi-Z source inverter

In single-stage power conversion, quasi-Z Source inverter (ZSI) provides buck-boost capability and permits shoot through state to enhance the input dc-link voltage. This article discusses the control system design for quasi-ZSI based three-phase grid-tied photovoltaic (PV) systems. The inclusion of a low pass filter in the shoot-through duty ratio control loop eliminates ripples in the calculated duty ratio. For tuning the controller gains, an analysis of bode diagrams for the system under consideration is presented. This theoretical analysis is validated by simulation studies using MATLAB/SIMULINK. The simulation studies reveal that the proposed control system design results in grid code compliant operation of grid-tied PV systems with sinusoidal currents injected at unity power factor. Moreover, PV operation at maximum power point is achieved with good steady-state and dynamic performance. Copyright (c) 2021 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference Additive Manufacturing and Advanced Materials-AM2 2021.