Study and integration of photovoltaic systems

Abstract

This thesis aimed to study the structure of an on grid photovoltaic system and to get by the aspect of integration of such system to the power network. The integration method can have different topologies and is usually based on power electronic devices controlled by dedicated controllers. In order to transform the direct output signal of the PV panels to an alternative signal connected to the utility network, the Modular Multilevel Converter (MMC) was used in this study. The challenges linked to this type of converters are associated with its sub-modules balancing control, the suppression of the circulating current, the complexity of its control, and its related performance. Simulation of the converter dynamic behavior including the related control technique is done through Matlab Simulink [1]. The adopted control strategy used is based on the reverse model predictive control and was used in order to reduce the computational burden by calculating the number of inserted MMC’s submodules directly, based on the reverse prediction of arm voltages. Preliminary results showed that the output of the used system presents reasonable accuracy when compared to the parameters of the tied- to electrical network. In addition a case study of a grid connected photovoltaic system is presented in this work: the site conditions, power aspects, topology, economical study are all presented for a particular application.