Design and analysis of a transformer-less single-phase grid-tie photovoltaic inverter using boost converter with Immittance conversion topology

摘要

The following paper presents a newly developed transformer-less grid-tie pure sine wave inverter (GTI) for photovoltaic (PV) application. The proposed topology employs a PV panel, a dual-stage switch mode boost converter, a voltage divider circuit, an H-bridge inverter and a T-LCL Immittance conversion filter circuit. For gate drive circuit of inverter, a combination of sinusoidal pulse width modulation (SPWM) and square wave signal under grid synchronization form are used. The proposed design has a various desirable features such as better utilization of the photovoltaic array, low cost, compact size, simpler control, and lower harmonics with higher efficiency. It highly reduces total harmonic distortion (THD) which is less than 0.5%, and swells inverter efficiency up to 98%. The proposed design is mathematically modeled which is simulated via PSIM and finally the results are presented to confirm the effectiveness of this grid-tie inverter viability.