Modelling and simulation of Multilevel Inverter for grid connected Photovoltaic system

This paper presents a grid-connected Photovoltaic (PV) system utilizing a 5-level Diode Clamped Multilevel Inverter (DCMI). A multilevel inverter is more advantageous over other conventional inverters and is suitable for a PV system as it improves the power quality and lowers the harmonic distortion using a suitable modulation technique. A closed loop control system is developed using Simulink environment for the 5 level DCMI. The system consists of a DC-DC converter, a 48V battery, a 5 level DCMI and a filter. A DC-DC converter is used to convert the PV voltage level suitable for the 48V battery. A battery is used to assist with the grid network in the event of unfavorable weather conditions. A feedback loop is proposed for a PV array, also known as maximum power point tracking (MPPT) which helps to extract maximum power under various operating conditions. Simulation results verify the performance of the 5 level D CMI design configuration and control strategy under various operating conditions.

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