A single phase multistring five-level inverter for grid connected PV system during constant solar radiation

This paper presents a single phase multistring five-level inverter for grid connected PV system with novel pwm switching scheme during constant solar radiation. Two PV strings parallel connected configuration interfaced to inverter, so as to produce five voltage level. Two identical reference signals with proper offset are compared with high frequency carrier signal to produce switching pulses. Instead of a conventional three-level pulse width-modulated (PWM) inverter, here a five-level inverter with novel PWM scheme is used because it gives advantages such as smaller filter size, improved output waveforms, lower total harmonic distortion (THD), lower electromagnetic interference. Also expansion of system becomes more easier. The validation of proposed scheme is done here through MAT LAB simulation.