Model Predictive Control of Z Source Inverter : Formulation & Simulation

This paper presents Model Predictive Control (MPC) of impedance-source (commonly known as Z-source) inverter in a three phase network. The Z-source converter employs a unique impedance circuitry to couple the converter main circuit to the power source, thus employing unique features that cannot be obtained in the traditional voltage-source and current-source inverters where a capacitor and inductor are used respectively. A typical model for a three phase ZSI using balanced load is developed, where MPC due to its feedback control algorithm, predicted the future output current across the load and solved an optimization problem with a view to selecting the optimal control. The quality of output waveform has been analysed by maintaining the total harmonic distortion (THD) at an optimum level. Moreover, an inverse relationship between THD and Switching frequency is also noted. In addition, inductor current & capacitor voltage has also been tracked and effect on THD is analyzed by changing values in source side inductor & resistor