Grid-Connected PV System Using a T-Type qZS Inverter with an Integral Time Derivative Approach to Ensure MPP and Decoupled Current Control

Three-level quasi-Z-Source (qZS) inverters based on the T-Type topology are especially indicated to be used in grid-connected PV systems. In fact, they present an important feature for this type of application since presents Buck-Boost characteristic. Besides that, is also characterized by high reliability and multilevel operation. However, associated to this converter, it must be used controllers that will ensure their best performance. In this context, this paper will propose a global control system for the three phase T-Type qZS inverter in a grid-connected PV System. So, it will be considered a MPPT algorithm based on a robust integral time derivative approach. For the output currents will be used a decoupled current controller in which will be associated to a SPWM modulator. The performance of the system will be verified and tested by simulation studies. The results will show that this system will provide results well adapted for this application.