Simplified reference signal generator equation for single phase grid-tied photovoltaic inverters

Abstract

The current controller for a single phase grid-tied photovoltaic (PV) inverters widely compete with a variety of methods. This paper concentrates on a ramp comparison method which mainly focus on pulse width modulation (PWM). In PWM, the reference with compensated error is compared to a triangle waveform. The desired reference current from the inverter is produced through the generated reference signal. Nevertheless, the conventional method becomes complex in determining the reference signal if the system's ac main voltage varied. Thus, this paper proposes a simplified equation of the reference signal in order to cut down the mathematical complexity. The simplified method is verified using a 5 kVA single phase half-bridge grid-tied inverter. The simulated result shows the difference of the error uncertainty for the desired reference current between conventional and simplified equations is ±0.02 %.