CURRENT CONTROL OF Z-SOURCE FOUR-LEG INVERTER FOR AUTONOMOUS PHOTOVOLTAIC SYSTEM BASED ON MODEL PREDICTIVE CONTROL

Abstract

The relevance. Renewable energy resources for electrical power generation have gained higher interest over the traditional underground fuels due to geo-reasons, such as the low generation cost and clean energy resources. Moreover, renewable energy resources, especially photovoltaic generation system, can efficiently be used as an autonomous power supply for consumers geographically located in remote, inaccessible areas. The performance of autonomous power supply depends mainly on the conversion system and its control technique. Therefore, this paper uses a new and alternative control system based on the finite control set model predictive control strategy to control the load current of the Z-source four-leg inverter employed for the autonomous photovoltaic generation system. The main aim of the research is the development of a control algorithm based on finite control set model predictive control strategy to regulate the load currents of Z-source four-leg inverter for a geographical stand-alone photovoltaic generation system. Methods: mathematical and computer modeling using the MatLab/Simulink software environment. Results. Due to using Z-source four-leg inverter, the power conversion system for the photovoltaic generation systems is reduced to be single-stage, instead of two-stage power conversion. The results show that the proposed control algorithm can effectively regulate load current under balanced/unbalanced issues with high controllability. The proposed control algorithm has excellent steady-state and transient performances.

Keywords

• renewable energy resources
• autonomous photovoltaic systems
• model predictive control
• four-leg inverter
• z-source inverter