DESIGN OF FUZZY CONTROLLER FOR GRID CONNECTED PHOTOVOLTAIC POWER GENERATION

Multilevel inverter technology has emerged recently as an important alternative in the area of high-power medium-voltage energy control. In this paper, a multilevel inverter topology is developed and applied for injecting the real power of renewable power into the grid to reduce the switching losses, total harmonic distortions and electromagnetic interference caused by switching operation of power electronic devices. The grid connected photovoltaic system consists of a solar cell array, dc-dc boost converter, a multi-level inverter are coupled to the load system. This multi-level inverter consists of two capacitors, a dual-buck converter, a full-bridge inverter and a filter. In photovoltaic grid connected systems, power electronic converters are used to convert the power, which is generated from PV panel and transfer to grid. So, the dc-dc converter, dc-ac inverters and their controllers are playing an important role in grid connected PV systems. The output power of solar cell array is dc power. So, the inverter is necessarily to convert the dc power to ac power and inject that power into grid. In this paper, five-level inverter with dual-buck converter is used. The dual-buck converter converts the dc voltage from PV panel into three level voltages. Further, the three level voltages is converted into five-level with the help of full-bridge inverter. The dc-dc converter and dc-ac inverter are controlled by developing fuzzy logic controller. The performance of the developed renewable power generation system is compared for Proportional-Integral controlled system and Fuzzy logic controlled system. However the Efficiency of using fuzzy controller to the system is increased