A study and implementation of three-level boost converter with MPPT for PV application

This paper presents present a study and implementation of a three-level boost converter. This converter feature includes low devices voltages stress requirement for high voltage application, small inductor size that leads to the reduction of cost and size and can be operated with a wide range input voltage. Unlike conventional method, output capacitor voltage balancing was done by a slight phase shift adjustment. Perturbation and Observation Maximum Power Point Tracking (MPPT) method is applied to the converter to track the maximum voltage in the different irradiation condition. A 5kW three-level boost converter with a wide range input voltage from 480V to 700V and high output voltage up to 750V was implemented. The MPPT control is realized by a digital signal processor (DSP) TMS320F28035. The efficiency of the prototype system can reach to 98% and the MPPT average accuracy reaches 98.5%.